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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull persistent dentry infrastructure and conversion from Al Viro:
"Some filesystems use a kinda-sorta controlled dentry refcount leak to
pin dentries of created objects in dcache (and undo it when removing
those). A reference is grabbed and not released, but it's not actually
_stored_ anywhere.
That works, but it's hard to follow and verify; among other things, we
have no way to tell _which_ of the increments is intended to be an
unpaired one. Worse, on removal we need to decide whether the
reference had already been dropped, which can be non-trivial if that
removal is on umount and we need to figure out if this dentry is
pinned due to e.g. unlink() not done. Usually that is handled by using
kill_litter_super() as ->kill_sb(), but there are open-coded special
cases of the same (consider e.g. /proc/self).
Things get simpler if we introduce a new dentry flag
(DCACHE_PERSISTENT) marking those "leaked" dentries. Having it set
claims responsibility for +1 in refcount.
The end result this series is aiming for:
- get these unbalanced dget() and dput() replaced with new primitives
that would, in addition to adjusting refcount, set and clear
persistency flag.
- instead of having kill_litter_super() mess with removing the
remaining "leaked" references (e.g. for all tmpfs files that hadn't
been removed prior to umount), have the regular
shrink_dcache_for_umount() strip DCACHE_PERSISTENT of all dentries,
dropping the corresponding reference if it had been set. After that
kill_litter_super() becomes an equivalent of kill_anon_super().
Doing that in a single step is not feasible - it would affect too many
places in too many filesystems. It has to be split into a series.
This work has really started early in 2024; quite a few preliminary
pieces have already gone into mainline. This chunk is finally getting
to the meat of that stuff - infrastructure and most of the conversions
to it.
Some pieces are still sitting in the local branches, but the bulk of
that stuff is here"
* tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
d_make_discardable(): warn if given a non-persistent dentry
kill securityfs_recursive_remove()
convert securityfs
get rid of kill_litter_super()
convert rust_binderfs
convert nfsctl
convert rpc_pipefs
convert hypfs
hypfs: swich hypfs_create_u64() to returning int
hypfs: switch hypfs_create_str() to returning int
hypfs: don't pin dentries twice
convert gadgetfs
gadgetfs: switch to simple_remove_by_name()
convert functionfs
functionfs: switch to simple_remove_by_name()
functionfs: fix the open/removal races
functionfs: need to cancel ->reset_work in ->kill_sb()
functionfs: don't bother with ffs->ref in ffs_data_{opened,closed}()
functionfs: don't abuse ffs_data_closed() on fs shutdown
convert selinuxfs
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull directory locking updates from Christian Brauner:
"This contains the work to add centralized APIs for directory locking
operations.
This series is part of a larger effort to change directory operation
locking to allow multiple concurrent operations in a directory. The
ultimate goal is to lock the target dentry(s) rather than the whole
parent directory.
To help with changing the locking protocol, this series centralizes
locking and lookup in new helper functions. The helpers establish a
pattern where it is the dentry that is being locked and unlocked
(currently the lock is held on dentry->d_parent->d_inode, but that can
change in the future).
This also changes vfs_mkdir() to unlock the parent on failure, as well
as dput()ing the dentry. This allows end_creating() to only require
the target dentry (which may be IS_ERR() after vfs_mkdir()), not the
parent"
* tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
nfsd: fix end_creating() conversion
VFS: introduce end_creating_keep()
VFS: change vfs_mkdir() to unlock on failure.
ecryptfs: use new start_creating/start_removing APIs
Add start_renaming_two_dentries()
VFS/ovl/smb: introduce start_renaming_dentry()
VFS/nfsd/ovl: introduce start_renaming() and end_renaming()
VFS: add start_creating_killable() and start_removing_killable()
VFS: introduce start_removing_dentry()
smb/server: use end_removing_noperm for for target of smb2_create_link()
VFS: introduce start_creating_noperm() and start_removing_noperm()
VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing()
VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()
VFS: tidy up do_unlinkat()
VFS: introduce start_dirop() and end_dirop()
debugfs: rename end_creating() to debugfs_end_creating()
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull namespace updates from Christian Brauner:
"This contains substantial namespace infrastructure changes including a new
system call, active reference counting, and extensive header cleanups.
The branch depends on the shared kbuild branch for -fms-extensions support.
Features:
- listns() system call
Add a new listns() system call that allows userspace to iterate
through namespaces in the system. This provides a programmatic
interface to discover and inspect namespaces, addressing
longstanding limitations:
Currently, there is no direct way for userspace to enumerate
namespaces. Applications must resort to scanning /proc/*/ns/ across
all processes, which is:
- Inefficient - requires iterating over all processes
- Incomplete - misses namespaces not attached to any running
process but kept alive by file descriptors, bind mounts, or
parent references
- Permission-heavy - requires access to /proc for many processes
- No ordering or ownership information
- No filtering per namespace type
The listns() system call solves these problems:
ssize_t listns(const struct ns_id_req *req, u64 *ns_ids,
size_t nr_ns_ids, unsigned int flags);
struct ns_id_req {
__u32 size;
__u32 spare;
__u64 ns_id;
struct /* listns */ {
__u32 ns_type;
__u32 spare2;
__u64 user_ns_id;
};
};
Features include:
- Pagination support for large namespace sets
- Filtering by namespace type (MNT_NS, NET_NS, USER_NS, etc.)
- Filtering by owning user namespace
- Permission checks respecting namespace isolation
- Active Reference Counting
Introduce an active reference count that tracks namespace
visibility to userspace. A namespace is visible in the following
cases:
- The namespace is in use by a task
- The namespace is persisted through a VFS object (namespace file
descriptor or bind-mount)
- The namespace is a hierarchical type and is the parent of child
namespaces
The active reference count does not regulate lifetime (that's still
done by the normal reference count) - it only regulates visibility
to namespace file handles and listns().
This prevents resurrection of namespaces that are pinned only for
internal kernel reasons (e.g., user namespaces held by
file->f_cred, lazy TLB references on idle CPUs, etc.) which should
not be accessible via (1)-(3).
- Unified Namespace Tree
Introduce a unified tree structure for all namespaces with:
- Fixed IDs assigned to initial namespaces
- Lookup based solely on inode number
- Maintained list of owned namespaces per user namespace
- Simplified rbtree comparison helpers
Cleanups
- Header Reorganization:
- Move namespace types into separate header (ns_common_types.h)
- Decouple nstree from ns_common header
- Move nstree types into separate header
- Switch to new ns_tree_{node,root} structures with helper functions
- Use guards for ns_tree_lock
- Initial Namespace Reference Count Optimization
- Make all reference counts on initial namespaces a nop to avoid
pointless cacheline ping-pong for namespaces that can never go
away
- Drop custom reference count initialization for initial namespaces
- Add NS_COMMON_INIT() macro and use it for all namespaces
- pid: rely on common reference count behavior
- Miscellaneous Cleanups
- Rename exit_task_namespaces() to exit_nsproxy_namespaces()
- Rename is_initial_namespace() and make argument const
- Use boolean to indicate anonymous mount namespace
- Simplify owner list iteration in nstree
- nsfs: raise SB_I_NODEV, SB_I_NOEXEC, and DCACHE_DONTCACHE explicitly
- nsfs: use inode_just_drop()
- pidfs: raise DCACHE_DONTCACHE explicitly
- pidfs: simplify PIDFD_GET__NAMESPACE ioctls
- libfs: allow to specify s_d_flags
- cgroup: add cgroup namespace to tree after owner is set
- nsproxy: fix free_nsproxy() and simplify create_new_namespaces()
Fixes:
- setns(pidfd, ...) race condition
Fix a subtle race when using pidfds with setns(). When the target
task exits after prepare_nsset() but before commit_nsset(), the
namespace's active reference count might have been dropped. If
setns() then installs the namespaces, it would bump the active
reference count from zero without taking the required reference on
the owner namespace, leading to underflow when later decremented.
The fix resurrects the ownership chain if necessary - if the caller
succeeded in grabbing passive references, the setns() should
succeed even if the target task exits or gets reaped.
- Return EFAULT on put_user() error instead of success
- Make sure references are dropped outside of RCU lock (some
namespaces like mount namespace sleep when putting the last
reference)
- Don't skip active reference count initialization for network
namespace
- Add asserts for active refcount underflow
- Add asserts for initial namespace reference counts (both passive
and active)
- ipc: enable is_ns_init_id() assertions
- Fix kernel-doc comments for internal nstree functions
- Selftests
- 15 active reference count tests
- 9 listns() functionality tests
- 7 listns() permission tests
- 12 inactive namespace resurrection tests
- 3 threaded active reference count tests
- commit_creds() active reference tests
- Pagination and stress tests
- EFAULT handling test
- nsid tests fixes"
* tag 'namespace-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (103 commits)
pidfs: simplify PIDFD_GET_<type>_NAMESPACE ioctls
nstree: fix kernel-doc comments for internal functions
nsproxy: fix free_nsproxy() and simplify create_new_namespaces()
selftests/namespaces: fix nsid tests
ns: drop custom reference count initialization for initial namespaces
pid: rely on common reference count behavior
ns: add asserts for initial namespace active reference counts
ns: add asserts for initial namespace reference counts
ns: make all reference counts on initial namespace a nop
ipc: enable is_ns_init_id() assertions
fs: use boolean to indicate anonymous mount namespace
ns: rename is_initial_namespace()
ns: make is_initial_namespace() argument const
nstree: use guards for ns_tree_lock
nstree: simplify owner list iteration
nstree: switch to new structures
nstree: add helper to operate on struct ns_tree_{node,root}
nstree: move nstree types into separate header
nstree: decouple from ns_common header
ns: move namespace types into separate header
...
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At this point there are very few call chains that might lead to
d_make_discardable() on a dentry that hadn't been made persistent:
calls of simple_unlink() and simple_rmdir() in configfs and
apparmorfs.
Both filesystems do pin (part of) their contents in dcache, but
they are currently playing very unusual games with that. Converting
them to more usual patterns might be possible, but it's definitely
going to be a long series of changes in both cases.
For now the easiest solution is to have both stop using simple_unlink()
and simple_rmdir() - that allows to make d_make_discardable() warn
when given a non-persistent dentry.
Rather than giving them full-blown private copies (with calls of
d_make_discardable() replaced with dput()), let's pull the parts of
simple_unlink() and simple_rmdir() that deal with timestamps and link
counts into separate helpers (__simple_unlink() and __simple_rmdir()
resp.) and have those used by configfs and apparmorfs.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Note that simple_unlink() et.al. are used by many filesystems; for now
they can not assume that persistency mark will have been set back
when the object got created. Once all conversions are done we'll
have them complain if called for something that had not been marked
persistent.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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should be paired with simple_start_creating() - unlocks parent and
drops dentry reference.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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simple_recursive_removal(), but instead of victim dentry it takes
parent + name.
Used to be open-coded in fs/fuse/control.c, but there's no need to expose
the guts of that thing there and there are other potential users, so
let's lift it into libfs...
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The fact that directory operations (create,remove,rename) are protected
by a lock on the parent is known widely throughout the kernel.
In order to change this - to instead lock the target dentry - it is
best to centralise this knowledge so it can be changed in one place.
This patch introduces start_dirop() which is local to VFS code.
It performs the required locking for create and remove. Rename
will be handled separately.
Various functions with names like start_creating() or start_removing_path(),
some of which already exist, will export this functionality beyond the VFS.
end_dirop() is the partner of start_dirop(). It drops the lock and
releases the reference on the dentry.
It *is* exported so that various end_creating etc functions can be inline.
As vfs_mkdir() drops the dentry on error we cannot use end_dirop() as
that won't unlock when the dentry IS_ERR(). For now we need an explicit
unlock when dentry IS_ERR(). I hope to change vfs_mkdir() to unlock
when it drops a dentry so that explicit unlock can go away.
end_dirop() can always be called on the result of start_dirop(), but not
after vfs_mkdir(). After a vfs_mkdir() we still may need the explicit
unlock as seen in end_creating_path().
As well as adding start_dirop() and end_dirop()
this patch uses them in:
- simple_start_creating (which requires sharing lookup_noperm_common()
with libfs.c)
- start_removing_path / start_removing_user_path_at
- filename_create / end_creating_path()
- do_rmdir(), do_unlinkat()
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20251113002050.676694-3-neilb@ownmail.net
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Make it possible for pseudo filesystems to specify default dentry flags.
Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-1-2e6f823ebdc0@kernel.org
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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All places were patched by coccinelle with the default expecting that
->i_lock is held, afterwards entries got fixed up by hand to use
unlocked variants as needed.
The script:
@@
expression inode, flags;
@@
- inode->i_state & flags
+ inode_state_read(inode) & flags
@@
expression inode, flags;
@@
- inode->i_state &= ~flags
+ inode_state_clear(inode, flags)
@@
expression inode, flag1, flag2;
@@
- inode->i_state &= ~flag1 & ~flag2
+ inode_state_clear(inode, flag1 | flag2)
@@
expression inode, flags;
@@
- inode->i_state |= flags
+ inode_state_set(inode, flags)
@@
expression inode, flags;
@@
- inode->i_state = flags
+ inode_state_assign(inode, flags)
@@
expression inode, flags;
@@
- flags = inode->i_state
+ flags = inode_state_read(inode)
@@
expression inode, flags;
@@
- READ_ONCE(inode->i_state) & flags
+ inode_state_read(inode) & flags
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pidfs updates from Christian Brauner:
- persistent info
Persist exit and coredump information independent of whether anyone
currently holds a pidfd for the struct pid.
The current scheme allocated pidfs dentries on-demand repeatedly.
This scheme is reaching it's limits as it makes it impossible to pin
information that needs to be available after the task has exited or
coredumped and that should not be lost simply because the pidfd got
closed temporarily. The next opener should still see the stashed
information.
This is also a prerequisite for supporting extended attributes on
pidfds to allow attaching meta information to them.
If someone opens a pidfd for a struct pid a pidfs dentry is allocated
and stashed in pid->stashed. Once the last pidfd for the struct pid
is closed the pidfs dentry is released and removed from pid->stashed.
So if 10 callers create a pidfs dentry for the same struct pid
sequentially, i.e., each closing the pidfd before the other creates a
new one then a new pidfs dentry is allocated every time.
Because multiple tasks acquiring and releasing a pidfd for the same
struct pid can race with each another a task may still find a valid
pidfs entry from the previous task in pid->stashed and reuse it. Or
it might find a dead dentry in there and fail to reuse it and so
stashes a new pidfs dentry. Multiple tasks may race to stash a new
pidfs dentry but only one will succeed, the other ones will put their
dentry.
The current scheme aims to ensure that a pidfs dentry for a struct
pid can only be created if the task is still alive or if a pidfs
dentry already existed before the task was reaped and so exit
information has been was stashed in the pidfs inode.
That's great except that it's buggy. If a pidfs dentry is stashed in
pid->stashed after pidfs_exit() but before __unhash_process() is
called we will return a pidfd for a reaped task without exit
information being available.
The pidfds_pid_valid() check does not guard against this race as it
doens't sync at all with pidfs_exit(). The pid_has_task() check might
be successful simply because we're before __unhash_process() but
after pidfs_exit().
Introduce a new scheme where the lifetime of information associated
with a pidfs entry (coredump and exit information) isn't bound to the
lifetime of the pidfs inode but the struct pid itself.
The first time a pidfs dentry is allocated for a struct pid a struct
pidfs_attr will be allocated which will be used to store exit and
coredump information.
If all pidfs for the pidfs dentry are closed the dentry and inode can
be cleaned up but the struct pidfs_attr will stick until the struct
pid itself is freed. This will ensure minimal memory usage while
persisting relevant information.
The new scheme has various advantages. First, it allows to close the
race where we end up handing out a pidfd for a reaped task for which
no exit information is available. Second, it minimizes memory usage.
Third, it allows to remove complex lifetime tracking via dentries
when registering a struct pid with pidfs. There's no need to get or
put a reference. Instead, the lifetime of exit and coredump
information associated with a struct pid is bound to the lifetime of
struct pid itself.
- extended attributes
Now that we have a way to persist information for pidfs dentries we
can start supporting extended attributes on pidfds. This will allow
userspace to attach meta information to tasks.
One natural extension would be to introduce a custom pidfs.* extended
attribute space and allow for the inheritance of extended attributes
across fork() and exec().
The first simple scheme will allow privileged userspace to set
trusted extended attributes on pidfs inodes.
- Allow autonomous pidfs file handles
Various filesystems such as pidfs and drm support opening file
handles without having to require a file descriptor to identify the
filesystem. The filesystem are global single instances and can be
trivially identified solely on the information encoded in the file
handle.
This makes it possible to not have to keep or acquire a sentinal file
descriptor just to pass it to open_by_handle_at() to identify the
filesystem. That's especially useful when such sentinel file
descriptor cannot or should not be acquired.
For pidfs this means a file handle can function as full replacement
for storing a pid in a file. Instead a file handle can be stored and
reopened purely based on the file handle.
Such autonomous file handles can be opened with or without specifying
a a file descriptor. If no proper file descriptor is used the
FD_PIDFS_ROOT sentinel must be passed. This allows us to define
further special negative fd sentinels in the future.
Userspace can trivially test for support by trying to open the file
handle with an invalid file descriptor.
- Allow pidfds for reaped tasks with SCM_PIDFD messages
This is a logical continuation of the earlier work to create pidfds
for reaped tasks through the SO_PEERPIDFD socket option merged in
923ea4d4482b ("Merge patch series "net, pidfs: enable handing out
pidfds for reaped sk->sk_peer_pid"").
- Two minor fixes:
* Fold fs_struct->{lock,seq} into a seqlock
* Don't bother with path_{get,put}() in unix_open_file()
* tag 'vfs-6.17-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (37 commits)
don't bother with path_get()/path_put() in unix_open_file()
fold fs_struct->{lock,seq} into a seqlock
selftests: net: extend SCM_PIDFD test to cover stale pidfds
af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD
af_unix: stash pidfs dentry when needed
af_unix/scm: fix whitespace errors
af_unix: introduce and use scm_replace_pid() helper
af_unix: introduce unix_skb_to_scm helper
af_unix: rework unix_maybe_add_creds() to allow sleep
selftests/pidfd: decode pidfd file handles withou having to specify an fd
fhandle, pidfs: support open_by_handle_at() purely based on file handle
uapi/fcntl: add FD_PIDFS_ROOT
uapi/fcntl: add FD_INVALID
fcntl/pidfd: redefine PIDFD_SELF_THREAD_GROUP
uapi/fcntl: mark range as reserved
fhandle: reflow get_path_anchor()
pidfs: add pidfs_root_path() helper
fhandle: rename to get_path_anchor()
fhandle: hoist copy_from_user() above get_path_from_fd()
fhandle: raise FILEID_IS_DIR in handle_type
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc VFS updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Add ext4 IOCB_DONTCACHE support
This refactors the address_space_operations write_begin() and
write_end() callbacks to take const struct kiocb * as their first
argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate
to the filesystem's buffered I/O path.
Ext4 is updated to implement handling of the IOCB_DONTCACHE flag
and advertises support via the FOP_DONTCACHE file operation flag.
Additionally, the i915 driver's shmem write paths are updated to
bypass the legacy write_begin/write_end interface in favor of
directly calling write_iter() with a constructed synchronous kiocb.
Another i915 change replaces a manual write loop with
kernel_write() during GEM shmem object creation.
Cleanups:
- don't duplicate vfs_open() in kernel_file_open()
- proc_fd_getattr(): don't bother with S_ISDIR() check
- fs/ecryptfs: replace snprintf with sysfs_emit in show function
- vfs: Remove unnecessary list_for_each_entry_safe() from
evict_inodes()
- filelock: add new locks_wake_up_waiter() helper
- fs: Remove three arguments from block_write_end()
- VFS: change old_dir and new_dir in struct renamedata to dentrys
- netfs: Remove unused declaration netfs_queue_write_request()
Fixes:
- eventpoll: Fix semi-unbounded recursion
- eventpoll: fix sphinx documentation build warning
- fs/read_write: Fix spelling typo
- fs: annotate data race between poll_schedule_timeout() and
pollwake()
- fs/pipe: set FMODE_NOWAIT in create_pipe_files()
- docs/vfs: update references to i_mutex to i_rwsem
- fs/buffer: remove comment about hard sectorsize
- fs/buffer: remove the min and max limit checks in __getblk_slow()
- fs/libfs: don't assume blocksize <= PAGE_SIZE in
generic_check_addressable
- fs_context: fix parameter name in infofc() macro
- fs: Prevent file descriptor table allocations exceeding INT_MAX"
* tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
netfs: Remove unused declaration netfs_queue_write_request()
eventpoll: fix sphinx documentation build warning
ext4: support uncached buffered I/O
mm/pagemap: add write_begin_get_folio() helper function
fs: change write_begin/write_end interface to take struct kiocb *
drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
drm/i915: Use kernel_write() in shmem object create
eventpoll: Fix semi-unbounded recursion
vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes()
fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable
fs/buffer: remove the min and max limit checks in __getblk_slow()
fs: Prevent file descriptor table allocations exceeding INT_MAX
fs: Remove three arguments from block_write_end()
fs/ecryptfs: replace snprintf with sysfs_emit in show function
fs: annotate suspected data race between poll_schedule_timeout() and pollwake()
docs/vfs: update references to i_mutex to i_rwsem
fs/buffer: remove comment about hard sectorsize
fs_context: fix parameter name in infofc() macro
VFS: change old_dir and new_dir in struct renamedata to dentrys
proc_fd_getattr(): don't bother with S_ISDIR() check
...
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull rpc_pipefs updates from Al Viro:
"Massage rpc_pipefs to use saner primitives and clean up the APIs
provided to the rest of the kernel"
* tag 'pull-rpc_pipefs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
rpc_create_client_dir(): return 0 or -E...
rpc_create_client_dir(): don't bother with rpc_populate()
rpc_new_dir(): the last argument is always NULL
rpc_pipe: expand the calls of rpc_mkdir_populate()
rpc_gssd_dummy_populate(): don't bother with rpc_populate()
rpc_mkpipe_dentry(): switch to simple_start_creating()
rpc_pipe: saner primitive for creating regular files
rpc_pipe: saner primitive for creating subdirectories
rpc_pipe: don't overdo directory locking
rpc_mkpipe_dentry(): saner calling conventions
rpc_unlink(): saner calling conventions
rpc_populate(): lift cleanup into callers
rpc_unlink(): use simple_recursive_removal()
rpc_{rmdir_,}depopulate(): use simple_recursive_removal() instead
rpc_pipe: clean failure exits in fill_super
new helper: simple_start_creating()
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull simple_recursive_removal() update from Al Viro:
"Removing subtrees of kernel filesystems is done in quite a few places;
unfortunately, it's easy to get wrong. A number of open-coded attempts
are out there, with varying amount of bogosities.
simple_recursive_removal() had been introduced for doing that with all
precautions needed; it does an equivalent of rm -rf, with sufficient
locking, eviction of anything mounted on top of the subtree, etc.
This series converts a bunch of open-coded instances to using that"
* tag 'pull-simple_recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
functionfs, gadgetfs: use simple_recursive_removal()
kill binderfs_remove_file()
fuse_ctl: use simple_recursive_removal()
pstore: switch to locked_recursive_removal()
binfmt_misc: switch to locked_recursive_removal()
spufs: switch to locked_recursive_removal()
add locked_recursive_removal()
better lockdep annotations for simple_recursive_removal()
simple_recursive_removal(): saner interaction with fsnotify
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dentry d_flags updates from Al Viro:
"The current exclusion rules for dentry->d_flags stores are rather
unpleasant. The basic rules are simple:
- stores to dentry->d_flags are OK under dentry->d_lock
- stores to dentry->d_flags are OK in the dentry constructor, before
becomes potentially visible to other threads
Unfortunately, there's a couple of exceptions to that, and that's
where the headache comes from.
The main PITA comes from d_set_d_op(); that primitive sets ->d_op of
dentry and adjusts the flags that correspond to presence of individual
methods. It's very easy to misuse; existing uses _are_ safe, but proof
of correctness is brittle.
Use in __d_alloc() is safe (we are within a constructor), but we might
as well precalculate the initial value of 'd_flags' when we set the
default ->d_op for given superblock and set 'd_flags' directly instead
of messing with that helper.
The reasons why other uses are safe are bloody convoluted; I'm not
going to reproduce it here. See [1] for gory details, if you care. The
critical part is using d_set_d_op() only just prior to
d_splice_alias(), which makes a combination of d_splice_alias() with
setting ->d_op, etc a natural replacement primitive.
Better yet, if we go that way, it's easy to take setting ->d_op and
modifying 'd_flags' under ->d_lock, which eliminates the headache as
far as 'd_flags' exclusion rules are concerned. Other exceptions are
minor and easy to deal with.
What this series does:
- d_set_d_op() is no longer available; instead a new primitive
(d_splice_alias_ops()) is provided, equivalent to combination of
d_set_d_op() and d_splice_alias().
- new field of struct super_block - 's_d_flags'. This sets the
default value of 'd_flags' to be used when allocating dentries on
this filesystem.
- new primitive for setting 's_d_op': set_default_d_op(). This
replaces stores to 's_d_op' at mount time.
All in-tree filesystems converted; out-of-tree ones will get caught
by the compiler ('s_d_op' is renamed, so stores to it will be
caught). 's_d_flags' is set by the same primitive to match the
's_d_op'.
- a lot of filesystems had sb->s_d_op->d_delete equal to
always_delete_dentry; that is equivalent to setting
DCACHE_DONTCACHE in 'd_flags', so such filesystems can bloody well
set that bit in 's_d_flags' and drop 'd_delete()' from
dentry_operations.
In quite a few cases that results in empty dentry_operations, which
means that we can get rid of those.
- kill simple_dentry_operations - not needed anymore
- massage d_alloc_parallel() to get rid of the other exception wrt
'd_flags' stores - we can set DCACHE_PAR_LOOKUP as soon as we
allocate the new dentry; no need to delay that until we commit to
using the sucker.
As the result, 'd_flags' stores are all either under ->d_lock or done
before the dentry becomes visible in any shared data structures"
Link: https://lore.kernel.org/all/20250224010624.GT1977892@ZenIV/ [1]
* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits)
configfs: use DCACHE_DONTCACHE
debugfs: use DCACHE_DONTCACHE
efivarfs: use DCACHE_DONTCACHE instead of always_delete_dentry()
9p: don't bother with always_delete_dentry
ramfs, hugetlbfs, mqueue: set DCACHE_DONTCACHE
kill simple_dentry_operations
devpts, sunrpc, hostfs: don't bother with ->d_op
shmem: no dentry retention past the refcount reaching zero
d_alloc_parallel(): set DCACHE_PAR_LOOKUP earlier
make d_set_d_op() static
simple_lookup(): just set DCACHE_DONTCACHE
tracefs: Add d_delete to remove negative dentries
set_default_d_op(): calculate the matching value for ->d_flags
correct the set of flags forbidden at d_set_d_op() time
split d_flags calculation out of d_set_d_op()
new helper: set_default_d_op()
fuse: no need for special dentry_operations for root dentry
switch procfs from d_set_d_op() to d_splice_alias_ops()
new helper: d_splice_alias_ops()
procfs: kill ->proc_dops
...
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Change the address_space_operations callbacks write_begin() and
write_end() to take struct kiocb * as the first argument instead of
struct file *.
Update all affected function prototypes, implementations, call sites,
and related documentation across VFS, filesystems, and block layer.
Part of a series refactoring address_space_operations write_begin and
write_end callbacks to use struct kiocb for passing write context and
flags.
Signed-off-by: Taotao Chen <chentaotao@didiglobal.com>
Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Since [1], it is possible for filesystems to have blocksize > PAGE_SIZE
of the system.
Remove the assumption and make the check generic for all blocksizes in
generic_check_addressable().
[1] https://lore.kernel.org/linux-xfs/20240822135018.1931258-1-kernel@pankajraghav.com/
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/20250630104018.213985-1-p.raghav@samsung.com
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Set the things up for kernel-initiated creation of object in
a tree-in-dcache filesystem. With respect to locking it's
an equivalent of filename_create() - we either get a negative
dentry with locked parent, or ERR_PTR() and no locks taken.
tracefs and debugfs had that open-coded as part of their
object creation machinery; switched to calling new helper.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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simple_recursive_removal() assumes that parent is not locked and
locks it when it finally gets to removing the victim itself.
Usually that's what we want, but there are places where the
parent is *already* locked and we need it to stay that way.
In those cases simple_recursive_removal() would, of course,
deadlock, so we have to play racy games with unlocking/relocking
the parent around the call or open-code the entire thing.
A better solution is to provide a variant that expects to
be called with the parent already locked by the caller.
Parent should be locked with I_MUTEX_PARENT, to avoid false
positives from lockdep.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We want a class that nests outside of I_MUTEX_NORMAL (for the sake of
callbacks that might want to lock the victim) and inside I_MUTEX_PARENT
(so that a variant of that could be used with parent of the victim
held locked by the caller).
In reality, simple_recursive_removal()
* never holds two locks at once
* holds the lock on parent of dentry passed to callback
* is used only on the trees with fixed topology, so the depths
are not changing.
So the locking order is actually fine.
AFAICS, the best solution is to assign I_MUTEX_CHILD to the locks
grabbed by that thing.
Reported-by: syzbot+169de184e9defe7fe709@syzkaller.appspotmail.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Making anonymous inodes regular files comes with a lot of risk and
regression potential as evidenced by a recent hickup in io_uring. We're
better of continuing to not have them be regular files. Since we have
S_ANON_INODE we can port all of our assertions easily.
Link: https://lore.kernel.org/20250702-work-fixes-v1-1-ff76ea589e33@kernel.org
Fixes: cfd86ef7e8e7 ("anon_inode: use a proper mode internally")
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: stable@kernel.org
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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VFS has switched to i_rwsem for ten years now (9902af79c01a: parallel
lookups actual switch to rwsem), but the VFS documentation and comments
still has references to i_mutex.
Signed-off-by: Junxuan Liao <ljx@cs.wisc.edu>
Link: https://lore.kernel.org/72223729-5471-474a-af3c-f366691fba82@cs.wisc.edu
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Allow for S_IMMUTABLE to be stripped so that we can support xattrs.
Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-10-98f3456fd552@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Make it a littler easier to follow.
Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-3-98f3456fd552@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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* Add a callback to struct stashed_operations so it's possible to
implement custom behavior for pidfs and allow for it to return errors.
* Teach stashed_dentry_get() to handle error pointers.
Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-2-98f3456fd552@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Make it match the real unlink(2)/rmdir(2) - notify *after* the
operation. And use fsnotify_delete() instead of messing with
fsnotify_unlink()/fsnotify_rmdir().
Currently the only caller that cares is the one in debugfs, and
there the order matching the normal syscalls makes more sense;
it'll get more serious for users introduced later in the series.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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No users left and anything that wants it would be better off just
setting DCACHE_DONTCACHE in their ->s_d_flags.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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No need to mess with ->d_op at all. Note that ->d_delete that always
returns 1 is equivalent to having DCACHE_DONTCACHE in ->d_flags.
Later the same thing will be placed into ->s_d_flags of the filesystems
where we want that behaviour for all dentries; then the check in
simple_lookup() will at least get unlikely() slapped on it.
NOTE: there are only two filesystems where
* simple_lookup() might be called
* default ->d_op is non-NULL
* its ->d_delete() doesn't always return 1
If not for those, we could have simple_lookup() just set DCACHE_DONTCACHE
without even looking at ->d_op. Filesystems in question are btrfs
and tracefs; both have ->d_delete() returning 1 on anything fed to
simple_lookup(), so both would be fine with simple_lookup() setting
DCACHE_DONTCACHE regardless of ->d_op.
IOW, we might want to drop the check for ->d_op in simple_lookup();
it's definitely a separate story, though.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... to be used instead of manually assigning to ->s_d_op.
All in-tree filesystem converted (and field itself is renamed,
so any out-of-tree ones in need of conversion will be caught
by compiler).
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs freezing updates from Christian Brauner:
"This contains various filesystem freezing related work for this cycle:
- Allow the power subsystem to support filesystem freeze for suspend
and hibernate.
Now all the pieces are in place to actually allow the power
subsystem to freeze/thaw filesystems during suspend/resume.
Filesystems are only frozen and thawed if the power subsystem does
actually own the freeze.
If the filesystem is already frozen by the time we've frozen all
userspace processes we don't care to freeze it again. That's
userspace's job once the process resumes. We only actually freeze
filesystems if we absolutely have to and we ignore other failures
to freeze.
We could bubble up errors and fail suspend/resume if the error
isn't EBUSY (aka it's already frozen) but I don't think that this
is worth it. Filesystem freezing during suspend/resume is
best-effort. If the user has 500 ext4 filesystems mounted and 4
fail to freeze for whatever reason then we simply skip them.
What we have now is already a big improvement and let's see how we
fare with it before making our lives even harder (and uglier) than
we have to.
- Allow efivars to support freeze and thaw
Allow efivarfs to partake to resync variable state during system
hibernation and suspend. Add freeze/thaw support.
This is a pretty straightforward implementation. We simply add
regular freeze/thaw support for both userspace and the kernel.
efivars is the first pseudofilesystem that adds support for
filesystem freezing and thawing.
The simplicity comes from the fact that we simply always resync
variable state after efivarfs has been frozen. It doesn't matter
whether that's because of suspend, userspace initiated freeze or
hibernation. Efivars is simple enough that it doesn't matter that
we walk all dentries. There are no directories and there aren't
insane amounts of entries and both freeze/thaw are already
heavy-handed operations. If userspace initiated a freeze/thaw cycle
they would need CAP_SYS_ADMIN in the initial user namespace (as
that's where efivarfs is mounted) so it can't be triggered by
random userspace. IOW, we really really don't care"
* tag 'vfs-6.16-rc1.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
f2fs: fix freezing filesystem during resize
kernfs: add warning about implementing freeze/thaw
efivarfs: support freeze/thaw
power: freeze filesystems during suspend/resume
libfs: export find_next_child()
super: add filesystem freezing helpers for suspend and hibernate
gfs2: pass through holder from the VFS for freeze/thaw
super: use common iterator (Part 2)
super: use a common iterator (Part 1)
super: skip dying superblocks early
super: simplify user_get_super()
super: remove pointless s_root checks
fs: allow all writers to be frozen
locking/percpu-rwsem: add freezable alternative to down_read
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Export find_next_child() so it can be used by efivarfs.
Keep it internal for now. There's no reason to advertise this
kernel-wide.
Link: https://lore.kernel.org/r/20250331-work-freeze-v1-1-6dfbe8253b9f@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This makes it easy to detect proper anonymous inodes and to ensure that
we can detect them in codepaths such as readahead().
Readahead on anonymous inodes didn't work because they didn't have a
proper mode. Now that they have we need to retain EINVAL being returned
otherwise LTP will fail.
We also need to ensure that ioctls aren't simply fired like they are for
regular files so things like inotify inodes continue to correctly call
their own ioctl handlers as in [1].
Reported-by: Xilin Wu <sophon@radxa.com>
Link: https://lore.kernel.org/3A9139D5CD543962+89831381-31b9-4392-87ec-a84a5b3507d8@radxa.com [1]
Link: https://lore.kernel.org/7a1a7076-ff6b-4cb0-94e7-7218a0a44028@sirena.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
This allows the VFS to not trip over anonymous inodes and we can add
asserts based on the mode into the vfs. When we report it to userspace
we can simply hide the mode to avoid regressions. I've audited all
direct callers of alloc_anon_inode() and only secretmen overrides i_mode
and i_op inode operations but it already uses a regular file.
Link: https://lore.kernel.org/20250407-work-anon_inode-v1-1-53a44c20d44e@kernel.org
Fixes: af153bb63a336 ("vfs: catch invalid modes in may_open()")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org # all LTS kernels
Reported-by: syzbot+5d8e79d323a13aa0b248@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67ed3fb3.050a0220.14623d.0009.GAE@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs pidfs updates from Christian Brauner:
- Allow retrieving exit information after a process has been reaped
through pidfds via the new PIDFD_INTO_EXIT extension for the
PIDFD_GET_INFO ioctl. Various tools need access to information about
a process/task even after it has already been reaped.
Pidfd polling allows waiting on either task exit or for a task to
have been reaped. The contract for PIDFD_INFO_EXIT is simply that
EPOLLHUP must be observed before exit information can be retrieved,
i.e., exit information is only provided once the task has been reaped
and then can be retrieved as long as the pidfd is open.
- Add PIDFD_SELF_{THREAD,THREAD_GROUP} sentinels allowing userspace to
forgo allocating a file descriptor for their own process. This is
useful in scenarios where users want to act on their own process
through pidfds and is akin to AT_FDCWD.
- Improve premature thread-group leader and subthread exec behavior
when polling on pidfds:
(1) During a multi-threaded exec by a subthread, i.e.,
non-thread-group leader thread, all other threads in the
thread-group including the thread-group leader are killed and the
struct pid of the thread-group leader will be taken over by the
subthread that called exec. IOW, two tasks change their TIDs.
(2) A premature thread-group leader exit means that the thread-group
leader exited before all of the other subthreads in the
thread-group have exited.
Both cases lead to inconsistencies for pidfd polling with
PIDFD_THREAD. Any caller that holds a PIDFD_THREAD pidfd to the
current thread-group leader may or may not see an exit notification
on the file descriptor depending on when poll is performed. If the
poll is performed before the exec of the subthread has concluded an
exit notification is generated for the old thread-group leader. If
the poll is performed after the exec of the subthread has concluded
no exit notification is generated for the old thread-group leader.
The correct behavior is to simply not generate an exit notification
on the struct pid of a subhthread exec because the struct pid is
taken over by the subthread and thus remains alive.
But this is difficult to handle because a thread-group may exit
premature as mentioned in (2). In that case an exit notification is
reliably generated but the subthreads may continue to run for an
indeterminate amount of time and thus also may exec at some point.
After this pull no exit notifications will be generated for a
PIDFD_THREAD pidfd for a thread-group leader until all subthreads
have been reaped. If a subthread should exec before no exit
notification will be generated until that task exits or it creates
subthreads and repeates the cycle.
This means an exit notification indicates the ability for the father
to reap the child.
* tag 'vfs-6.15-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (25 commits)
selftests/pidfd: third test for multi-threaded exec polling
selftests/pidfd: second test for multi-threaded exec polling
selftests/pidfd: first test for multi-threaded exec polling
pidfs: improve multi-threaded exec and premature thread-group leader exit polling
pidfs: ensure that PIDFS_INFO_EXIT is available
selftests/pidfd: add seventh PIDFD_INFO_EXIT selftest
selftests/pidfd: add sixth PIDFD_INFO_EXIT selftest
selftests/pidfd: add fifth PIDFD_INFO_EXIT selftest
selftests/pidfd: add fourth PIDFD_INFO_EXIT selftest
selftests/pidfd: add third PIDFD_INFO_EXIT selftest
selftests/pidfd: add second PIDFD_INFO_EXIT selftest
selftests/pidfd: add first PIDFD_INFO_EXIT selftest
selftests/pidfd: expand common pidfd header
pidfs/selftests: ensure correct headers for ioctl handling
selftests/pidfd: fix header inclusion
pidfs: allow to retrieve exit information
pidfs: record exit code and cgroupid at exit
pidfs: use private inode slab cache
pidfs: move setting flags into pidfs_alloc_file()
pidfd: rely on automatic cleanup in __pidfd_prepare()
...
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There is an issue in the kernel:
In tmpfs, when using the "ls" command to list the contents
of a directory with a large number of files, glibc performs
the getdents call in multiple rounds. If a concurrent unlink
occurs between these getdents calls, it may lead to duplicate
directory entries in the ls output. One possible reproduction
scenario is as follows:
Create 1026 files and execute ls and rm concurrently:
for i in {1..1026}; do
echo "This is file $i" > /tmp/dir/file$i
done
ls /tmp/dir rm /tmp/dir/file4
->getdents(file1026-file5)
->unlink(file4)
->getdents(file5,file3,file2,file1)
It is expected that the second getdents call to return file3
through file1, but instead it returns an extra file5.
The root cause of this problem is in the offset_dir_lookup
function. It uses mas_find to determine the starting position
for the current getdents call. Since mas_find locates the first
position that is greater than or equal to mas->index, when file4
is deleted, it ends up returning file5.
It can be fixed by replacing mas_find with mas_find_rev, which
finds the first position that is less than or equal to mas->index.
Fixes: b9b588f22a0c ("libfs: Use d_children list to iterate simple_offset directories")
Signed-off-by: Yongjian Sun <sunyongjian1@huawei.com>
Link: https://lore.kernel.org/r/20250320034417.555810-1-sunyongjian@huaweicloud.com
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Record the exit code and cgroupid in release_task() and stash in struct
pidfs_exit_info so it can be retrieved even after the task has been
reaped.
Link: https://lore.kernel.org/r/20250305-work-pidfs-kill_on_last_close-v3-5-c8c3d8361705@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs d_revalidate updates from Al Viro:
"Provide stable parent and name to ->d_revalidate() instances
Most of the filesystem methods where we care about dentry name and
parent have their stability guaranteed by the callers;
->d_revalidate() is the major exception.
It's easy enough for callers to supply stable values for expected name
and expected parent of the dentry being validated. That kills quite a
bit of boilerplate in ->d_revalidate() instances, along with a bunch
of races where they used to access ->d_name without sufficient
precautions"
* tag 'pull-revalidate' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
9p: fix ->rename_sem exclusion
orangefs_d_revalidate(): use stable parent inode and name passed by caller
ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller
nfs: fix ->d_revalidate() UAF on ->d_name accesses
nfs{,4}_lookup_validate(): use stable parent inode passed by caller
gfs2_drevalidate(): use stable parent inode and name passed by caller
fuse_dentry_revalidate(): use stable parent inode and name passed by caller
vfat_revalidate{,_ci}(): use stable parent inode passed by caller
exfat_d_revalidate(): use stable parent inode passed by caller
fscrypt_d_revalidate(): use stable parent inode passed by caller
ceph_d_revalidate(): propagate stable name down into request encoding
ceph_d_revalidate(): use stable parent inode passed by caller
afs_d_revalidate(): use stable name and parent inode passed by caller
Pass parent directory inode and expected name to ->d_revalidate()
generic_ci_d_compare(): use shortname_storage
ext4 fast_commit: make use of name_snapshot primitives
dissolve external_name.u into separate members
make take_dentry_name_snapshot() lockless
dcache: back inline names with a struct-wrapped array of unsigned long
make sure that DNAME_INLINE_LEN is a multiple of word size
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... and check the "name might be unstable" predicate
the right way.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs libfs updates from Christian Brauner:
"This improves the stable directory offset behavior in various ways.
Stable offsets are needed so that NFS can reliably read directories on
filesystems such as tmpfs:
- Improve the end-of-directory detection
According to getdents(3), the d_off field in each returned
directory entry points to the next entry in the directory. The
d_off field in the last returned entry in the readdir buffer must
contain a valid offset value, but if it points to an actual
directory entry, then readdir/getdents can loop.
Introduce a specific fixed offset value that is placed in the d_off
field of the last entry in a directory. Some user space
applications assume that the EOD offset value is larger than the
offsets of real directory entries, so the largest valid offset
value is reserved for this purpose. This new value is never
allocated by simple_offset_add().
When ->iterate_dir() returns, getdents{64} inserts the ctx->pos
value into the d_off field of the last valid entry in the readdir
buffer. When it hits EOD, offset_readdir() sets ctx->pos to the EOD
offset value so the last entry is updated to point to the EOD
marker.
When trying to read the entry at the EOD offset, offset_readdir()
terminates immediately.
- Rely on d_children to iterate stable offset directories
Instead of using the mtree to emit entries in the order of their
offset values, use it only to map incoming ctx->pos to a starting
entry. Then use the directory's d_children list, which is already
maintained properly by the dcache, to find the next child to emit.
- Narrow the range of directory offset values returned by
simple_offset_add() to 3 .. (S32_MAX - 1) on all platforms. This
means the allocation behavior is identical on 32-bit systems,
64-bit systems, and 32-bit user space on 64-bit kernels. The new
range still permits over 2 billion concurrent entries per
directory.
- Return ENOSPC when the directory offset range is exhausted. Hitting
this error is almost impossible though.
- Remove the simple_offset_empty() helper"
* tag 'vfs-6.14-rc1.libfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
libfs: Use d_children list to iterate simple_offset directories
libfs: Replace simple_offset end-of-directory detection
Revert "libfs: fix infinite directory reads for offset dir"
Revert "libfs: Add simple_offset_empty()"
libfs: Return ENOSPC when the directory offset range is exhausted
|
|
The mtree mechanism has been effective at creating directory offsets
that are stable over multiple opendir instances. However, it has not
been able to handle the subtleties of renames that are concurrent
with readdir.
Instead of using the mtree to emit entries in the order of their
offset values, use it only to map incoming ctx->pos to a starting
entry. Then use the directory's d_children list, which is already
maintained properly by the dcache, to find the next child to emit.
One of the sneaky things about this is that when the mtree-allocated
offset value wraps (which is very rare), looking up ctx->pos++ is
not going to find the next entry; it will return NULL. Instead, by
following the d_children list, the offset values can appear in any
order but all of the entries in the directory will be visited
eventually.
Note also that the readdir() is guaranteed to reach the tail of this
list. Entries are added only at the head of d_children, and readdir
walks from its current position in that list towards its tail.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-6-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
According to getdents(3), the d_off field in each returned directory
entry points to the next entry in the directory. The d_off field in
the last returned entry in the readdir buffer must contain a valid
offset value, but if it points to an actual directory entry, then
readdir/getdents can loop.
This patch introduces a specific fixed offset value that is placed
in the d_off field of the last entry in a directory. Some user space
applications assume that the EOD offset value is larger than the
offsets of real directory entries, so the largest valid offset value
is reserved for this purpose. This new value is never allocated by
simple_offset_add().
When ->iterate_dir() returns, getdents{64} inserts the ctx->pos
value into the d_off field of the last valid entry in the readdir
buffer. When it hits EOD, offset_readdir() sets ctx->pos to the EOD
offset value so the last entry is updated to point to the EOD marker.
When trying to read the entry at the EOD offset, offset_readdir()
terminates immediately.
It is worth noting that using a Maple tree for directory offset
value allocation does not guarantee a 63-bit range of values --
on platforms where "long" is a 32-bit type, the directory offset
value range is still 0..(2^31 - 1). For broad compatibility with
32-bit user space, the largest tmpfs directory cookie value is now
S32_MAX.
Fixes: 796432efab1e ("libfs: getdents() should return 0 after reaching EOD")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-5-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
The current directory offset allocator (based on mtree_alloc_cyclic)
stores the next offset value to return in octx->next_offset. This
mechanism typically returns values that increase monotonically over
time. Eventually, though, the newly allocated offset value wraps
back to a low number (say, 2) which is smaller than other already-
allocated offset values.
Yu Kuai <yukuai3@huawei.com> reports that, after commit 64a7ce76fb90
("libfs: fix infinite directory reads for offset dir"), if a
directory's offset allocator wraps, existing entries are no longer
visible via readdir/getdents because offset_readdir() stops listing
entries once an entry's offset is larger than octx->next_offset.
These entries vanish persistently -- they can be looked up, but will
never again appear in readdir(3) output.
The reason for this is that the commit treats directory offsets as
monotonically increasing integer values rather than opaque cookies,
and introduces this comparison:
if (dentry2offset(dentry) >= last_index) {
On 64-bit platforms, the directory offset value upper bound is
2^63 - 1. Directory offsets will monotonically increase for millions
of years without wrapping.
On 32-bit platforms, however, LONG_MAX is 2^31 - 1. The allocator
can wrap after only a few weeks (at worst).
Revert commit 64a7ce76fb90 ("libfs: fix infinite directory reads for
offset dir") to prepare for a fix that can work properly on 32-bit
systems and might apply to recent LTS kernels where shmem employs
the simple_offset mechanism.
Reported-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-4-cel@kernel.org
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
simple_empty() and simple_offset_empty() perform the same task.
The latter's use as a canary to find bugs has not found any new
issues. A subsequent patch will remove the use of the mtree for
iterating directory contents, so revert back to using a similar
mechanism for determining whether a directory is indeed empty.
Only one such mechanism is ever needed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-3-cel@kernel.org
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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Testing shows that the EBUSY error return from mtree_alloc_cyclic()
leaks into user space. The ERRORS section of "man creat(2)" says:
> EBUSY O_EXCL was specified in flags and pathname refers
> to a block device that is in use by the system
> (e.g., it is mounted).
ENOSPC is closer to what applications expect in this situation.
Note that the normal range of simple directory offset values is
2..2^63, so hitting this error is going to be rare to impossible.
Fixes: 6faddda69f62 ("libfs: Add directory operations for stable offsets")
Cc: stable@vger.kernel.org # v6.9+
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20241228175522.1854234-2-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Pseudo-filesystems might reasonably wish to implement the export ops
(particularly for name_to_handle_at/open_by_handle_at); plumb this
through pseudo_fs_context
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Erin Shepherd <erin.shepherd@e43.eu>
Link: https://lore.kernel.org/r/20241113-pidfs_fh-v2-1-9a4d28155a37@e43.eu
Link: https://lore.kernel.org/r/20241129-work-pidfs-file_handle-v1-1-87d803a42495@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
Pull statx updates from Al Viro:
"Sanitize struct filename and lookup flags handling in statx and
friends"
* tag 'pull-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
libfs: kill empty_dir_getattr()
fs: Simplify getattr interface function checking AT_GETATTR_NOSEC flag
fs/stat.c: switch to CLASS(fd_raw)
kill getname_statx_lookup_flags()
io_statx_prep(): use getname_uflags()
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It's used only to initialize ->getattr in one inode_operations instance
(empty_dir_inode_operations) and its behaviour had always been equivalent
to what we get with NULL ->getattr.
Just remove that initializer, along with empty_dir_getattr() itself.
While we are at it, the same instance has ->permission initialized to
generic_permission, which is what NULL ->permission ends up doing.
Again, no point keeping it.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Enable casefold lookup in tmpfs, based on the encoding defined by
userspace. That means that instead of comparing byte per byte a file
name, it compares to a case-insensitive equivalent of the Unicode
string.
* Dcache handling
There's a special need when dealing with case-insensitive dentries.
First of all, we currently invalidated every negative casefold dentries.
That happens because currently VFS code has no proper support to deal
with that, giving that it could incorrectly reuse a previous filename
for a new file that has a casefold match. For instance, this could
happen:
$ mkdir DIR
$ rm -r DIR
$ mkdir dir
$ ls
DIR/
And would be perceived as inconsistency from userspace point of view,
because even that we match files in a case-insensitive manner, we still
honor whatever is the initial filename.
Along with that, tmpfs stores only the first equivalent name dentry used
in the dcache, preventing duplications of dentries in the dcache. The
d_compare() version for casefold files uses a normalized string, so the
filename under lookup will be compared to another normalized string for
the existing file, achieving a casefolded lookup.
* Enabling casefold via mount options
Most filesystems have their data stored in disk, so casefold option need
to be enabled when building a filesystem on a device (via mkfs).
However, as tmpfs is a RAM backed filesystem, there's no disk
information and thus no mkfs to store information about casefold.
For tmpfs, create casefold options for mounting. Userspace can then
enable casefold support for a mount point using:
$ mount -t tmpfs -o casefold=utf8-12.1.0 fs_name mount_dir/
Userspace must set what Unicode standard is aiming to. The available
options depends on what the kernel Unicode subsystem supports.
And for strict encoding:
$ mount -t tmpfs -o casefold=utf8-12.1.0,strict_encoding fs_name mount_dir/
Strict encoding means that tmpfs will refuse to create invalid UTF-8
sequences. When this option is not enabled, any invalid sequence will be
treated as an opaque byte sequence, ignoring the encoding thus not being
able to be looked up in a case-insensitive way.
* Check for casefold dirs on simple_lookup()
On simple_lookup(), do not create dentries for casefold directories.
Currently, VFS does not support case-insensitive negative dentries and
can create inconsistencies in the filesystem. Prevent such dentries to
being created in the first place.
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-6-f443d5814194@igalia.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Export generic_ci_ dentry functions so they can be used by
case-insensitive filesystems that need something more custom than the
default one set by `struct generic_ci_dentry_ops`.
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-5-f443d5814194@igalia.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs folio updates from Christian Brauner:
"This contains work to port write_begin and write_end to rely on folios
for various filesystems.
This converts ocfs2, vboxfs, orangefs, jffs2, hostfs, fuse, f2fs,
ecryptfs, ntfs3, nilfs2, reiserfs, minixfs, qnx6, sysv, ufs, and
squashfs.
After this series lands a bunch of the filesystems in this list do not
mention struct page anymore"
* tag 'vfs-6.12.folio' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (61 commits)
Squashfs: Ensure all readahead pages have been used
Squashfs: Rewrite and update squashfs_readahead_fragment() to not use page->index
Squashfs: Update squashfs_readpage_block() to not use page->index
Squashfs: Update squashfs_readahead() to not use page->index
Squashfs: Update page_actor to not use page->index
jffs2: Use a folio in jffs2_garbage_collect_dnode()
jffs2: Convert jffs2_do_readpage_nolock to take a folio
buffer: Convert __block_write_begin() to take a folio
ocfs2: Convert ocfs2_write_zero_page to use a folio
fs: Convert aops->write_begin to take a folio
fs: Convert aops->write_end to take a folio
vboxsf: Use a folio in vboxsf_write_end()
orangefs: Convert orangefs_write_begin() to use a folio
orangefs: Convert orangefs_write_end() to use a folio
jffs2: Convert jffs2_write_begin() to use a folio
jffs2: Convert jffs2_write_end() to use a folio
hostfs: Convert hostfs_write_end() to use a folio
fuse: Convert fuse_write_begin() to use a folio
fuse: Convert fuse_write_end() to use a folio
f2fs: Convert f2fs_write_begin() to use a folio
...
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gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual pile of misc updates:
Features:
- Add F_CREATED_QUERY fcntl() that allows userspace to query whether
a file was actually created. Often userspace wants to know whether
an O_CREATE request did actually create a file without using
O_EXCL. The current logic is that to first attempts to open the
file without O_CREAT | O_EXCL and if ENOENT is returned userspace
tries again with both flags. If that succeeds all is well. If it
now reports EEXIST it retries.
That works fairly well but some corner cases make this more
involved. If this operates on a dangling symlink the first openat()
without O_CREAT | O_EXCL will return ENOENT but the second openat()
with O_CREAT | O_EXCL will fail with EEXIST.
The reason is that openat() without O_CREAT | O_EXCL follows the
symlink while O_CREAT | O_EXCL doesn't for security reasons. So
it's not something we can really change unless we add an explicit
opt-in via O_FOLLOW which seems really ugly.
All available workarounds are really nasty (fanotify, bpf lsm etc)
so add a simple fcntl().
- Try an opportunistic lookup for O_CREAT. Today, when opening a file
we'll typically do a fast lookup, but if O_CREAT is set, the kernel
always takes the exclusive inode lock. This was likely done with
the expectation that O_CREAT means that we always expect to do the
create, but that's often not the case. Many programs set O_CREAT
even in scenarios where the file already exists (see related
F_CREATED_QUERY patch motivation above).
The series contained in the pr rearranges the pathwalk-for-open
code to also attempt a fast_lookup in certain O_CREAT cases. If a
positive dentry is found, the inode_lock can be avoided altogether
and it can stay in rcuwalk mode for the last step_into.
- Expose the 64 bit mount id via name_to_handle_at()
Now that we provide a unique 64-bit mount ID interface in statx(2),
we can now provide a race-free way for name_to_handle_at(2) to
provide a file handle and corresponding mount without needing to
worry about racing with /proc/mountinfo parsing or having to open a
file just to do statx(2).
While this is not necessary if you are using AT_EMPTY_PATH and
don't care about an extra statx(2) call, users that pass full paths
into name_to_handle_at(2) need to know which mount the file handle
comes from (to make sure they don't try to open_by_handle_at a file
handle from a different filesystem) and switching to AT_EMPTY_PATH
would require allocating a file for every name_to_handle_at(2) call
- Add a per dentry expire timeout to autofs
There are two fairly well known automounter map formats, the autofs
format and the amd format (more or less System V and Berkley).
Some time ago Linux autofs added an amd map format parser that
implemented a fair amount of the amd functionality. This was done
within the autofs infrastructure and some functionality wasn't
implemented because it either didn't make sense or required extra
kernel changes. The idea was to restrict changes to be within the
existing autofs functionality as much as possible and leave changes
with a wider scope to be considered later.
One of these changes is implementing the amd options:
1) "unmount", expire this mount according to a timeout (same as
the current autofs default).
2) "nounmount", don't expire this mount (same as setting the
autofs timeout to 0 except only for this specific mount) .
3) "utimeout=<seconds>", expire this mount using the specified
timeout (again same as setting the autofs timeout but only for
this mount)
To implement these options per-dentry expire timeouts need to be
implemented for autofs indirect mounts. This is because all map
keys (mounts) for autofs indirect mounts use an expire timeout
stored in the autofs mount super block info. structure and all
indirect mounts use the same expire timeout.
Fixes:
- Fix missing fput for FSCONFIG_SET_FD in autofs
- Use param->file for FSCONFIG_SET_FD in coda
- Delete the 'fs/netfs' proc subtreee when netfs module exits
- Make sure that struct uid_gid_map fits into a single cacheline
- Don't flush in-flight wb switches for superblocks without cgroup
writeback
- Correcting the idmapping mount example in the idmapping
documentation
- Fix a race between evice_inodes() and find_inode() and iput()
- Refine the show_inode_state() macro definition in writeback code
- Prevent dump_mapping() from accessing invalid dentry.d_name.name
- Show actual source for debugfs in /proc/mounts
- Annotate data-race of busy_poll_usecs in eventpoll
- Don't WARN for racy path_noexec check in exec code
- Handle OOM on mnt_warn_timestamp_expiry()
- Fix some spelling in the iomap design documentation
- Fix typo in procfs comment
- Fix typo in fs/namespace.c comment
Cleanups:
- Add the VFS git tree to the MAINTAINERS file
- Move FMODE_UNSIGNED_OFFSET to fop_flags freeing up another f_mode
bit in struct file bringing us to 5 free f_mode bits
- Remove the __I_DIO_WAKEUP bit from i_state flags as we can simplify
the wait mechanism
- Remove the unused path_put_init() helper
- Replace a __u32 with u32 for s_fsnotify_mask as __u32 is uapi
specific
- Replace the unsigned long i_state member with a u32 i_state member
in struct inode freeing up 4 bytes in struct inode. Instead of
using the bit based wait apis we're now using the var event apis
and using the individual bytes of the i_state member to wait on
state changes
- Explain how per-syscall AT_* flags should be allocated
- Use in_group_or_capable() helper to simplify the posix acl mode
update code
- Switch to LIST_HEAD() in fsync_buffers_list() to simplify the code
- Removed comment about d_rcu_to_refcount() as that function doesn't
exist anymore
- Add kernel documentation for lookup_fast()
- Don't re-zero evenpoll fields
- Remove outdated comment after close_fd()
- Fix imprecise wording in comment about the pipe filesystem
- Drop GFP_NOFAIL mode from alloc_page_buffers
- Missing blank line warnings and struct declaration improved in
file_table
- Annotate struct poll_list with __counted_by()
- Remove the unused read parameter in percpu-rwsem
- Remove linux/prefetch.h include from direct-io code
- Use kmemdup_array instead of kmemdup for multiple allocation in
mnt_idmapping code
- Remove unused mnt_cursor_del() declaration
Performance tweaks:
- Dodge smp_mb in break_lease and break_deleg in the common case
- Only read fops once in fops_{get,put}()
- Use RCU in ilookup()
- Elide smp_mb in iversion handling in the common case
- Drop one lock trip in evict()"
* tag 'vfs-6.12.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (58 commits)
uidgid: make sure we fit into one cacheline
proc: Fix typo in the comment
fs/pipe: Correct imprecise wording in comment
fhandle: expose u64 mount id to name_to_handle_at(2)
uapi: explain how per-syscall AT_* flags should be allocated
fs: drop GFP_NOFAIL mode from alloc_page_buffers
writeback: Refine the show_inode_state() macro definition
fs/inode: Prevent dump_mapping() accessing invalid dentry.d_name.name
mnt_idmapping: Use kmemdup_array instead of kmemdup for multiple allocation
netfs: Delete subtree of 'fs/netfs' when netfs module exits
fs: use LIST_HEAD() to simplify code
inode: make i_state a u32
inode: port __I_LRU_ISOLATING to var event
vfs: fix race between evice_inodes() and find_inode()&iput()
inode: port __I_NEW to var event
inode: port __I_SYNC to var event
fs: reorder i_state bits
fs: add i_state helpers
MAINTAINERS: add the VFS git tree
fs: s/__u32/u32/ for s_fsnotify_mask
...
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get_stashed_dentry() tries to optimistically retrieve a stashed dentry
from a provided location. It needs to ensure to hold rcu lock before it
dereference the stashed location to prevent UAF issues. Use
rcu_dereference() instead of READ_ONCE() it's effectively equivalent
with some lockdep bells and whistles and it communicates clearly that
this expects rcu protection.
Link: https://lore.kernel.org/r/20240906-vfs-hotfix-5959800ffa68@brauner
Fixes: 07fd7c329839 ("libfs: add path_from_stashed()")
Reported-by: syzbot+f82b36bffae7ef78b6a7@syzkaller.appspotmail.com
Fixes: syzbot+f82b36bffae7ef78b6a7@syzkaller.appspotmail.com
Reported-by: syzbot+cbe4b96e1194b0e34db6@syzkaller.appspotmail.com
Fixes: syzbot+cbe4b96e1194b0e34db6@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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According to bpftrace on these routines most calls result in cmpxchg,
which already provides the same guarantee.
In inode_maybe_inc_iversion elision is possible because even if the
wrong value was read due to now missing smp_mb fence, the issue is going
to correct itself after cmpxchg. If it appears cmpxchg wont be issued,
the fence + reload are there bringing back previous behavior.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20240815083310.3865-1-mjguzik@gmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
After we switch tmpfs dir operations from simple_dir_operations to
simple_offset_dir_operations, every rename happened will fill new dentry
to dest dir's maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free
key starting with octx->newx_offset, and then set newx_offset equals to
free key + 1. This will lead to infinite readdir combine with rename
happened at the same time, which fail generic/736 in xfstests(detail show
as below).
1. create 5000 files(1 2 3...) under one dir
2. call readdir(man 3 readdir) once, and get one entry
3. rename(entry, "TEMPFILE"), then rename("TEMPFILE", entry)
4. loop 2~3, until readdir return nothing or we loop too many
times(tmpfs break test with the second condition)
We choose the same logic what commit 9b378f6ad48cf ("btrfs: fix infinite
directory reads") to fix it, record the last_index when we open dir, and
do not emit the entry which index >= last_index. The file->private_data
now used in offset dir can use directly to do this, and we also update
the last_index when we llseek the dir file.
Fixes: a2e459555c5f ("shmem: stable directory offsets")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Link: https://lore.kernel.org/r/20240731043835.1828697-1-yangerkun@huawei.com
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
[brauner: only update last_index after seek when offset is zero like Jan suggested]
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Convert all callers from working on a page to working on one page
of a folio (support for working on an entire folio can come later).
Removes a lot of folio->page->folio conversions.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Most callers have a folio, and most implementations operate on a folio,
so remove the conversion from folio->page->folio to fit through this
interface.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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generic_ci_match can be used by case-insensitive filesystems to compare
strings under lookup with dirents in a case-insensitive way. This
function is currently reimplemented by each filesystem supporting
casefolding, so this reduces code duplication in filesystem-specific
code.
[eugen.hristev@collabora.com: rework to first test the exact match, cleanup
and add error message]
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
Link: https://lore.kernel.org/r/20240606073353.47130-4-eugen.hristev@collabora.com
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
When renaming onto an existing directory entry, user space expects
the replacement entry to have the same directory offset as the
original one.
Link: https://gitlab.alpinelinux.org/alpine/aports/-/issues/15966
Fixes: a2e459555c5f ("shmem: stable directory offsets")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-4-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
I'm about to fix a tmpfs rename bug that requires the use of
internal simple_offset helpers that are not available in mm/shmem.c
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-3-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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User space expects the replacement (old) directory entry to have
the same directory offset after the rename.
Suggested-by: Christian Brauner <brauner@kernel.org>
Fixes: a2e459555c5f ("shmem: stable directory offsets")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-2-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
As Linus suggested this enables pidfs unconditionally. A key property to
retain is the ability to compare pidfds by inode number (cf. [1]).
That's extremely helpful just as comparing namespace file descriptors by
inode number is. They are used in a variety of scenarios where they need
to be compared, e.g., when receiving a pidfd via SO_PEERPIDFD from a
socket to trivially authenticate a the sender and various other
use-cases.
For 64bit systems this is pretty trivial to do. For 32bit it's slightly
more annoying as we discussed but we simply add a dumb ida based
allocator that gets used on 32bit. This gives the same guarantees about
inode numbers on 64bit without any overflow risk. Practically, we'll
never run into overflow issues because we're constrained by the number
of processes that can exist on 32bit and by the number of open files
that can exist on a 32bit system. On 64bit none of this matters and
things are very simple.
If 32bit also needs the uniqueness guarantee they can simply parse the
contents of /proc/<pid>/fd/<nr>. The uniqueness guarantees have a
variety of use-cases. One of the most obvious ones is that they will
make pidfiles (or "pidfdfiles", I guess) reliable as the unique
identifier can be placed into there that won't be reycled. Also a
frequent request.
Note, I took the chance and simplified path_from_stashed() even further.
Instead of passing the inode number explicitly to path_from_stashed() we
let the filesystem handle that internally. So path_from_stashed() ends
up even simpler than it is now. This is also a good solution allowing
the cleanup code to be clean and consistent between 32bit and 64bit. The
cleanup path in prepare_anon_dentry() is also switched around so we put
the inode before the dentry allocation. This means we only have to call
the cleanup handler for the filesystem's inode data once and can rely
->evict_inode() otherwise.
Aside from having to have a bit of extra code for 32bit it actually ends
up a nice cleanup for path_from_stashed() imho.
Tested on both 32 and 64bit including error injection.
Link: https://github.com/systemd/systemd/pull/31713 [1]
Link: https://lore.kernel.org/r/20240312-dingo-sehnlich-b3ecc35c6de7@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull file locking updates from Christian Brauner:
"A few years ago struct file_lock_context was added to allow for
separate lists to track different types of file locks instead of using
a singly-linked list for all of them.
Now leases no longer need to be tracked using struct file_lock.
However, a lot of the infrastructure is identical for leases and locks
so separating them isn't trivial.
This splits a group of fields used by both file locks and leases into
a new struct file_lock_core. The new core struct is embedded in struct
file_lock. Coccinelle was used to convert a lot of the callers to deal
with the move, with the remaining 25% or so converted by hand.
Afterwards several internal functions in fs/locks.c are made to work
with struct file_lock_core. Ultimately this allows to split struct
file_lock into struct file_lock and struct file_lease. The file lease
APIs are then converted to take struct file_lease"
* tag 'vfs-6.9.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (51 commits)
filelock: fix deadlock detection in POSIX locking
filelock: always define for_each_file_lock()
smb: remove redundant check
filelock: don't do security checks on nfsd setlease calls
filelock: split leases out of struct file_lock
filelock: remove temporary compatibility macros
smb/server: adapt to breakup of struct file_lock
smb/client: adapt to breakup of struct file_lock
ocfs2: adapt to breakup of struct file_lock
nfsd: adapt to breakup of struct file_lock
nfs: adapt to breakup of struct file_lock
lockd: adapt to breakup of struct file_lock
fuse: adapt to breakup of struct file_lock
gfs2: adapt to breakup of struct file_lock
dlm: adapt to breakup of struct file_lock
ceph: adapt to breakup of struct file_lock
afs: adapt to breakup of struct file_lock
9p: adapt to breakup of struct file_lock
filelock: convert seqfile handling to use file_lock_core
filelock: convert locks_translate_pid to take file_lock_core
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pdfd updates from Christian Brauner:
- Until now pidfds could only be created for thread-group leaders but
not for threads. There was no technical reason for this. We simply
had no users that needed support for this. Now we do have users that
need support for this.
This introduces a new PIDFD_THREAD flag for pidfd_open(). If that
flag is set pidfd_open() creates a pidfd that refers to a specific
thread.
In addition, we now allow clone() and clone3() to be called with
CLONE_PIDFD | CLONE_THREAD which wasn't possible before.
A pidfd that refers to an individual thread differs from a pidfd that
refers to a thread-group leader:
(1) Pidfds are pollable. A task may poll a pidfd and get notified
when the task has exited.
For thread-group leader pidfds the polling task is woken if the
thread-group is empty. In other words, if the thread-group
leader task exits when there are still threads alive in its
thread-group the polling task will not be woken when the
thread-group leader exits but rather when the last thread in the
thread-group exits.
For thread-specific pidfds the polling task is woken if the
thread exits.
(2) Passing a thread-group leader pidfd to pidfd_send_signal() will
generate thread-group directed signals like kill(2) does.
Passing a thread-specific pidfd to pidfd_send_signal() will
generate thread-specific signals like tgkill(2) does.
The default scope of the signal is thus determined by the type
of the pidfd.
Since use-cases exist where the default scope of the provided
pidfd needs to be overriden the following flags are added to
pidfd_send_signal():
- PIDFD_SIGNAL_THREAD
Send a thread-specific signal.
- PIDFD_SIGNAL_THREAD_GROUP
Send a thread-group directed signal.
- PIDFD_SIGNAL_PROCESS_GROUP
Send a process-group directed signal.
The scope change will only work if the struct pid is actually
used for this scope.
For example, in order to send a thread-group directed signal the
provided pidfd must be used as a thread-group leader and
similarly for PIDFD_SIGNAL_PROCESS_GROUP the struct pid must be
used as a process group leader.
- Move pidfds from the anonymous inode infrastructure to a tiny pseudo
filesystem. This will unblock further work that we weren't able to do
simply because of the very justified limitations of anonymous inodes.
Moving pidfds to a tiny pseudo filesystem allows for statx on pidfds
to become useful for the first time. They can now be compared by
inode number which are unique for the system lifetime.
Instead of stashing struct pid in file->private_data we can now stash
it in inode->i_private. This makes it possible to introduce concepts
that operate on a process once all file descriptors have been closed.
A concrete example is kill-on-last-close. Another side-effect is that
file->private_data is now freed up for per-file options for pidfds.
Now, each struct pid will refer to a different inode but the same
struct pid will refer to the same inode if it's opened multiple
times. In contrast to now where each struct pid refers to the same
inode.
The tiny pseudo filesystem is not visible anywhere in userspace
exactly like e.g., pipefs and sockfs. There's no lookup, there's no
complex inode operations, nothing. Dentries and inodes are always
deleted when the last pidfd is closed.
We allocate a new inode and dentry for each struct pid and we reuse
that inode and dentry for all pidfds that refer to the same struct
pid. The code is entirely optional and fairly small. If it's not
selected we fallback to anonymous inodes. Heavily inspired by nsfs.
The dentry and inode allocation mechanism is moved into generic
infrastructure that is now shared between nsfs and pidfs. The
path_from_stashed() helper must be provided with a stashing location,
an inode number, a mount, and the private data that is supposed to be
used and it will provide a path that can be passed to dentry_open().
The helper will try retrieve an existing dentry from the provided
stashing location. If a valid dentry is found it is reused. If not a
new one is allocated and we try to stash it in the provided location.
If this fails we retry until we either find an existing dentry or the
newly allocated dentry could be stashed. Subsequent openers of the
same namespace or task are then able to reuse it.
- Currently it is only possible to get notified when a task has exited,
i.e., become a zombie and userspace gets notified with EPOLLIN. We
now also support waiting until the task has been reaped, notifying
userspace with EPOLLHUP.
- Ensure that ESRCH is reported for getfd if a task is exiting instead
of the confusing EBADF.
- Various smaller cleanups to pidfd functions.
* tag 'vfs-6.9.pidfd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
libfs: improve path_from_stashed()
libfs: add stashed_dentry_prune()
libfs: improve path_from_stashed() helper
pidfs: convert to path_from_stashed() helper
nsfs: convert to path_from_stashed() helper
libfs: add path_from_stashed()
pidfd: add pidfs
pidfd: move struct pidfd_fops
pidfd: allow to override signal scope in pidfd_send_signal()
pidfd: change pidfd_send_signal() to respect PIDFD_THREAD
signal: fill in si_code in prepare_kill_siginfo()
selftests: add ESRCH tests for pidfd_getfd()
pidfd: getfd should always report ESRCH if a task is exiting
pidfd: clone: allow CLONE_THREAD | CLONE_PIDFD together
pidfd: exit: kill the no longer used thread_group_exited()
pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN))
pid: kill the obsolete PIDTYPE_PID code in transfer_pid()
pidfd: kill the no longer needed do_notify_pidfd() in de_thread()
pidfd_poll: report POLLHUP when pid_task() == NULL
pidfd: implement PIDFD_THREAD flag for pidfd_open()
...
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krisman/unicode into vfs.misc
Merge case-insensitive updates from Gabriel Krisman Bertazi:
- Patch case-insensitive lookup by trying the case-exact comparison
first, before falling back to costly utf8 casefolded comparison.
- Fix to forbid using a case-insensitive directory as part of an
overlayfs mount.
- Patchset to ensure d_op are set at d_alloc time for fscrypt and
casefold volumes, ensuring filesystem dentries will all have the
correct ops, whether they come from a lookup or not.
* tag 'for-next-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krisman/unicode:
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Right now we pass a bunch of info that is fs specific which doesn't make
a lot of sense and it bleeds fs sepcific details into the generic
helper. nsfs and pidfs have slightly different needs when initializing
inodes. Add simple operations that are stashed in sb->s_fs_info that
both can implement. This also allows us to get rid of cleaning up
references in the caller. All in all path_from_stashed() becomes way
simpler.
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Both pidfs and nsfs use a memory location to stash a dentry for reuse by
concurrent openers. Right now two custom
dentry->d_prune::{ns,pidfs}_prune_dentry() methods are needed that do
the same thing. The only thing that differs is that they need to get to
the memory location to store or retrieve the dentry from differently.
Fix that by remember the stashing location for the dentry in
dentry->d_fsdata which allows us to retrieve it in dentry->d_prune. That
in turn makes it possible to add a common helper that pidfs and nsfs can
both use.
Link: https://lore.kernel.org/r/CAHk-=wg8cHY=i3m6RnXQ2Y2W8psicKWQEZq1=94ivUiviM-0OA@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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In earlier patches we moved both nsfs and pidfs to path_from_stashed().
The helper currently tries to add and stash a new dentry if a reusable
dentry couldn't be found and returns EAGAIN if it lost the race to stash
the dentry. The caller can use EAGAIN to retry.
The helper and the two filesystems be written in a way that makes
returning EAGAIN unnecessary. To do this we need to change the
dentry->d_prune() implementation of nsfs and pidfs to not simply replace
the stashed dentry with NULL but to use a cmpxchg() and only replace
their own dentry.
Then path_from_stashed() can then be changed to not just stash a new
dentry when no dentry is currently stashed but also when an already dead
dentry is stashed. If another task managed to install a dentry in the
meantime it can simply be reused. Pack that into a loop and call it a
day.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wgtLF5Z5=15-LKAczWm=-tUjHO+Bpf7WjBG+UU3s=fEQw@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Moving pidfds from the anonymous inode infrastructure to a separate tiny
in-kernel filesystem similar to sockfs, pipefs, and anon_inodefs causes
selinux denials and thus various userspace components that make heavy
use of pidfds to fail as pidfds used anon_inode_getfile() which aren't
subject to any LSM hooks. But dentry_open() is and that would cause
regressions.
The failures that are seen are selinux denials. But the core failure is
dbus-broker. That cascades into other services failing that depend on
dbus-broker. For example, when dbus-broker fails to start polkit and all
the others won't be able to work because they depend on dbus-broker.
The reason for dbus-broker failing is because it doesn't handle failures
for SO_PEERPIDFD correctly. Last kernel release we introduced
SO_PEERPIDFD (and SCM_PIDFD). SO_PEERPIDFD allows dbus-broker and polkit
and others to receive a pidfd for the peer of an AF_UNIX socket. This is
the first time in the history of Linux that we can safely authenticate
clients in a race-free manner.
dbus-broker immediately made use of this but messed up the error
checking. It only allowed EINVAL as a valid failure for SO_PEERPIDFD.
That's obviously problematic not just because of LSM denials but because
of seccomp denials that would prevent SO_PEERPIDFD from working; or any
other new error code from there.
So this is catching a flawed implementation in dbus-broker as well. It
has to fallback to the old pid-based authentication when SO_PEERPIDFD
doesn't work no matter the reasons otherwise it'll always risk such
failures. So overall that LSM denial should not have caused dbus-broker
to fail. It can never assume that a feature released one kernel ago like
SO_PEERPIDFD can be assumed to be available.
So, the next fix separate from the selinux policy update is to try and
fix dbus-broker at [3]. That should make it into Fedora as well. In
addition the selinux reference policy should also be updated. See [4]
for that. If Selinux is in enforcing mode in userspace and it encounters
anything that it doesn't know about it will deny it by default. And the
policy is entirely in userspace including declaring new types for stuff
like nsfs or pidfs to allow it.
For now we continue to raise S_PRIVATE on the inode if it's a pidfs
inode which means things behave exactly like before.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2265630
Link: https://github.com/fedora-selinux/selinux-policy/pull/2050
Link: https://github.com/bus1/dbus-broker/pull/343 [3]
Link: https://github.com/SELinuxProject/refpolicy/pull/762 [4]
Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240222190334.GA412503@dev-arch.thelio-3990X
Link: https://lore.kernel.org/r/20240218-neufahrzeuge-brauhaus-fb0eb6459771@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a helper for both nsfs and pidfs to reuse an already stashed dentry
or to add and stash a new dentry.
Link: https://lore.kernel.org/r/20240218-neufahrzeuge-brauhaus-fb0eb6459771@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
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No filesystems depend on it anymore, and it is generally a bad idea.
Since all dentries should have the same set of dentry operations in
case-insensitive capable filesystems, it should be propagated through
->s_d_op.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-11-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
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In preparation to drop the similar helper that sets d_op at lookup time,
add a version to set the right d_op filesystem-wide, through sb->s_d_op.
The operations structures are shared across filesystems supporting
fscrypt and/or casefolding, therefore we can keep it in common libfs
code.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-7-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
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In preparation to get case-insensitive dentry operations from sb->s_d_op
again, use the same structure with and without fscrypt.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-6-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
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Casefolded comparisons are (obviously) way more costly than a simple
memcmp. Try the case-sensitive comparison first, falling-back to the
case-insensitive lookup only when needed. This allows any exact-match
lookup to complete without having to walk the utf8 trie.
Note that, for strict mode, generic_ci_d_compare used to reject an
invalid UTF-8 string, which would now be considered valid if it
exact-matches the disk-name. But, if that is the case, the filesystem
is corrupt. More than that, it really doesn't matter in practice,
because the name-under-lookup will have already been rejected by
generic_ci_d_hash and we won't even get here.
The memcmp is safe under RCU because we are operating on str/len instead
of dentry->d_name directly, and the caller guarantees their consistency
between each other in __d_lookup_rcu_op_compare.
Link: https://lore.kernel.org/r/87ttn2sip7.fsf_-_@mailhost.krisman.be
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
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https://lore.kernel.org/r/170820083431.6328.16233178852085891453.stgit@91.116.238.104.host.secureserver.net
Pull simple offset series from Chuck Lever
In an effort to address slab fragmentation issues reported a few
months ago, I've replaced the use of xarrays for the directory
offset map in "simple" file systems (including tmpfs).
Thanks to Liam Howlett for helping me get this working with Maple
Trees.
* series 'Use Maple Trees for simple_offset utilities' of https://lore.kernel.org/r/170820083431.6328.16233178852085891453.stgit@91.116.238.104.host.secureserver.net: (6 commits)
libfs: Convert simple directory offsets to use a Maple Tree
test_maple_tree: testing the cyclic allocation
maple_tree: Add mtree_alloc_cyclic()
libfs: Add simple_offset_empty()
libfs: Define a minimum directory offset
libfs: Re-arrange locking in offset_iterate_dir()
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Test robot reports:
> kernel test robot noticed a -19.0% regression of aim9.disk_src.ops_per_sec on:
>
> commit: a2e459555c5f9da3e619b7e47a63f98574dc75f1 ("shmem: stable directory offsets")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
Feng Tang further clarifies that:
> ... the new simple_offset_add()
> called by shmem_mknod() brings extra cost related with slab,
> specifically the 'radix_tree_node', which cause the regression.
Willy's analysis is that, over time, the test workload causes
xa_alloc_cyclic() to fragment the underlying SLAB cache.
This patch replaces the offset_ctx's xarray with a Maple Tree in the
hope that Maple Tree's dense node mode will handle this scenario
more scalably.
In addition, we can widen the simple directory offset maximum to
signed long (as loff_t is also signed).
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202309081306.3ecb3734-oliver.sang@intel.com
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820145616.6328.12620992971699079156.stgit@91.116.238.104.host.secureserver.net
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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For simple filesystems that use directory offset mapping, rely
strictly on the directory offset map to tell when a directory has
no children.
After this patch is applied, the emptiness test holds only the RCU
read lock when the directory being tested has no children.
In addition, this adds another layer of confirmation that
simple_offset_add/remove() are working as expected.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820143463.6328.7872919188371286951.stgit@91.116.238.104.host.secureserver.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This value is used in several places, so make it a symbolic
constant.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820142741.6328.12428356024575347885.stgit@91.116.238.104.host.secureserver.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Liam and Matthew say that once the RCU read lock is released,
xa_state is not safe to re-use for the next xas_find() call. But the
RCU read lock must be released on each loop iteration so that
dput(), which might_sleep(), can be called safely.
Thus we are forced to walk the offset tree with fresh state for each
directory entry. xa_find() can do this for us, though it might be a
little less efficient than maintaining xa_state locally.
We believe that in the current code base, inode->i_rwsem provides
protection for the xa_state maintained in
offset_iterate_dir(). However, there is no guarantee that will
continue to be the case in the future.
Since offset_iterate_dir() doesn't build xa_state locally any more,
there's no longer a strong need for offset_find_next(). Clean up by
rolling these two helpers together.
Suggested-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Message-ID: <170785993027.11135.8830043889278631735.stgit@91.116.238.104.host.secureserver.net>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820142021.6328.15047865406275957018.stgit@91.116.238.104.host.secureserver.net
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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ret is assigned first, so it does not need to initialize the assignment.
Signed-off-by: Li zeming <zeming@nfschina.com>
Link: https://lore.kernel.org/r/20240220062030.114203-1-zeming@nfschina.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a new struct file_lease and move the lease-specific fields from
struct file_lock to it. Convert the appropriate API calls to take
struct file_lease instead, and convert the callers to use them.
There is zero overlap between the lock manager operations for file
locks and the ones for file leases, so split the lease-related
operations off into a new lease_manager_operations struct.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-47-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache updates from Al Viro:
"Change of locking rules for __dentry_kill(), regularized refcounting
rules in that area, assorted cleanups and removal of weird corner
cases (e.g. now ->d_iput() on child is always called before the parent
might hit __dentry_kill(), etc)"
* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
dcache: remove unnecessary NULL check in dget_dlock()
kill DCACHE_MAY_FREE
__d_unalias() doesn't use inode argument
d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant
get rid of DCACHE_GENOCIDE
d_genocide(): move the extern into fs/internal.h
simple_fill_super(): don't bother with d_genocide() on failure
nsfs: use d_make_root()
d_alloc_pseudo(): move setting ->d_op there from the (sole) caller
kill d_instantate_anon(), fold __d_instantiate_anon() into remaining caller
retain_dentry(): introduce a trimmed-down lockless variant
__dentry_kill(): new locking scheme
d_prune_aliases(): use a shrink list
switch select_collect{,2}() to use of to_shrink_list()
to_shrink_list(): call only if refcount is 0
fold dentry_kill() into dput()
don't try to cut corners in shrink_lock_dentry()
fold the call of retain_dentry() into fast_dput()
Call retain_dentry() with refcount 0
dentry_kill(): don't bother with retain_dentry() on slow path
...
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Failing ->fill_super() will be followed by ->kill_sb(), which should
include kill_litter_super() if the call of simple_fill_super() had
been asked to create anything besides the root dentry. So there's
no need to empty the partially populated tree - it will be trimmed
by inevitable kill_litter_super().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Saves a pointer per struct dentry and actually makes the things less
clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use
of hlist_for_... iterators.
A couple of new helpers - d_first_child() and d_next_sibling(),
to make the expressions less awful.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The new directory offset helpers don't conform with the convention
of getdents() returning no more entries once a directory file
descriptor has reached the current end-of-directory.
To address this, copy the logic from dcache_readdir() to mark the
open directory file descriptor once EOD has been reached. Seeking
resets the mark.
Reported-by: Tavian Barnes <tavianator@tavianator.com>
Closes: https://lore.kernel.org/linux-fsdevel/20231113180616.2831430-1-tavianator@tavianator.com/
Fixes: 6faddda69f62 ("libfs: Add directory operations for stable offsets")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170043792492.4628.15646203084646716134.stgit@bazille.1015granger.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fanotify fsid updates from Christian Brauner:
"This work is part of the plan to enable fanotify to serve as a drop-in
replacement for inotify. While inotify is availabe on all filesystems,
fanotify currently isn't.
In order to support fanotify on all filesystems two things are needed:
(1) all filesystems need to support AT_HANDLE_FID
(2) all filesystems need to report a non-zero f_fsid
This contains (1) and allows filesystems to encode non-decodable file
handlers for fanotify without implementing any exportfs operations by
encoding a file id of type FILEID_INO64_GEN from i_ino and
i_generation.
Filesystems that want to opt out of encoding non-decodable file ids
for fanotify that don't support NFS export can do so by providing an
empty export_operations struct.
This also partially addresses (2) by generating f_fsid for simple
filesystems as well as freevxfs. Remaining filesystems will be dealt
with by separate patches.
Finally, this contains the patch from the current exportfs maintainers
which moves exportfs under vfs with Chuck, Jeff, and Amir as
maintainers and vfs.git as tree"
* tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
MAINTAINERS: create an entry for exportfs
fs: fix build error with CONFIG_EXPORTFS=m or not defined
freevxfs: derive f_fsid from bdev->bd_dev
fs: report f_fsid from s_dev for "simple" filesystems
exportfs: support encoding non-decodeable file handles by default
exportfs: define FILEID_INO64_GEN* file handle types
exportfs: make ->encode_fh() a mandatory method for NFS export
exportfs: add helpers to check if filesystem can encode/decode file handles
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Many of the filesystems that call the generic exportfs helpers do not
select the EXPORTFS config.
Move generic_encode_ino32_fh() to libfs.c, same as generic_fh_to_*()
to avoid having to fix all those config dependencies.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310262151.renqMvme-lkp@intel.com/
Fixes: dfaf653dc415 ("exportfs: make ->encode_fh() a mandatory method for NFS export")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231026204540.143217-1-amir73il@gmail.com
Tested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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There are many "simple" filesystems (*) that report null f_fsid in
statfs(2). Those "simple" filesystems report sb->s_dev as the st_dev
field of the stat syscalls for all inodes of the filesystem (**).
In order to enable fanotify reporting of events with fsid on those
"simple" filesystems, report the sb->s_dev number in f_fsid field of
statfs(2).
(*) For most of the "simple" filesystem refered to in this commit, the
->statfs() operation is simple_statfs(). Some of those fs assign the
simple_statfs() method directly in their ->s_op struct and some assign it
indirectly via a call to simple_fill_super() or to pseudo_fs_fill_super()
with either custom or "simple" s_op.
We also make the same change to efivarfs and hugetlbfs, although they do
not use simple_statfs(), because they use the simple_* inode opreations
(e.g. simple_lookup()).
(**) For most of the "simple" filesystems, the ->getattr() method is not
assigned, so stat() is implemented by generic_fillattr(). A few "simple"
filesystem use the simple_getattr() method which also calls
generic_fillattr() to fill most of the stat struct.
The two exceptions are procfs and 9p. procfs implements several different
->getattr() methods, but they all end up calling generic_fillattr() to
fill the st_dev field from sb->s_dev.
9p has more complicated ->getattr() methods, but they too, end up calling
generic_fillattr() to fill the st_dev field from sb->s_dev.
Note that 9p and kernfs also call simple_statfs() from custom ->statfs()
methods which already fill the f_fsid field, but v9fs_statfs() calls
simple_statfs() only in case f_fsid was not filled and kenrfs_statfs()
overwrites f_fsid after calling simple_statfs().
Link: https://lore.kernel.org/r/20230919094820.g5bwharbmy2dq46w@quack3/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231023143049.2944970-1-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Recently, we converted the ctime accesses in the kernel to use new
accessor functions. Linus recently pointed out though that if we add
accessors for the atime and mtime, then that would allow us to
seamlessly change how these timestamps are stored in the inode.
Add new accessor functions for the atime and mtime that mirror the
accessors for the ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185239.80830-1-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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If we fail filemap_write_and_wait_range() on the range the buffered write went
into, we only report the "number of bytes which we direct-written", to quote
the comment in there. Which is fine, but buffered write has already advanced
iocb->ki_pos, so we need to roll that back. Otherwise we end up with e.g.
write(2) advancing position by more than the amount it reports having written.
Fixes: 182c25e9c157 "filemap: update ki_pos in generic_perform_write"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Message-Id: <20230827214518.GU3390869@ZenIV>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"Many ext4 and jbd2 cleanups and bug fixes:
- Cleanups in the ext4 remount code when going to and from read-only
- Cleanups in ext4's multiblock allocator
- Cleanups in the jbd2 setup/mounting code paths
- Performance improvements when appending to a delayed allocation file
- Miscellaneous syzbot and other bug fixes"
* tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits)
ext4: fix slab-use-after-free in ext4_es_insert_extent()
libfs: remove redundant checks of s_encoding
ext4: remove redundant checks of s_encoding
ext4: reject casefold inode flag without casefold feature
ext4: use LIST_HEAD() to initialize the list_head in mballoc.c
ext4: do not mark inode dirty every time when appending using delalloc
ext4: rename s_error_work to s_sb_upd_work
ext4: add periodic superblock update check
ext4: drop dio overwrite only flag and associated warning
ext4: add correct group descriptors and reserved GDT blocks to system zone
ext4: remove unused function declaration
ext4: mballoc: avoid garbage value from err
ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple()
ext4: change the type of blocksize in ext4_mb_init_cache()
ext4: fix unttached inode after power cut with orphan file feature enabled
jbd2: correct the end of the journal recovery scan range
ext4: ext4_get_{dev}_journal return proper error value
ext4: cleanup ext4_get_dev_journal() and ext4_get_journal()
jbd2: jbd2_journal_init_{dev,inode} return proper error return value
jbd2: drop useless error tag in jbd2_journal_wipe()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual filesystems.
Features:
- Block mode changes on symlinks and rectify our broken semantics
- Report file modifications via fsnotify() for splice
- Allow specifying an explicit timeout for the "rootwait" kernel
command line option. This allows to timeout and reboot instead of
always waiting indefinitely for the root device to show up
- Use synchronous fput for the close system call
Cleanups:
- Get rid of open-coded lockdep workarounds for async io submitters
and replace it all with a single consolidated helper
- Simplify epoll allocation helper
- Convert simple_write_begin and simple_write_end to use a folio
- Convert page_cache_pipe_buf_confirm() to use a folio
- Simplify __range_close to avoid pointless locking
- Disable per-cpu buffer head cache for isolated cpus
- Port ecryptfs to kmap_local_page() api
- Remove redundant initialization of pointer buf in pipe code
- Unexport the d_genocide() function which is only used within core
vfs
- Replace printk(KERN_ERR) and WARN_ON() with WARN()
Fixes:
- Fix various kernel-doc issues
- Fix refcount underflow for eventfds when used as EFD_SEMAPHORE
- Fix a mainly theoretical issue in devpts
- Check the return value of __getblk() in reiserfs
- Fix a racy assert in i_readcount_dec
- Fix integer conversion issues in various functions
- Fix LSM security context handling during automounts that prevented
NFS superblock sharing"
* tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
cachefiles: use kiocb_{start,end}_write() helpers
ovl: use kiocb_{start,end}_write() helpers
aio: use kiocb_{start,end}_write() helpers
io_uring: use kiocb_{start,end}_write() helpers
fs: create kiocb_{start,end}_write() helpers
fs: add kerneldoc to file_{start,end}_write() helpers
io_uring: rename kiocb_end_write() local helper
splice: Convert page_cache_pipe_buf_confirm() to use a folio
libfs: Convert simple_write_begin and simple_write_end to use a folio
fs/dcache: Replace printk and WARN_ON by WARN
fs/pipe: remove redundant initialization of pointer buf
fs: Fix kernel-doc warnings
devpts: Fix kernel-doc warnings
doc: idmappings: fix an error and rephrase a paragraph
init: Add support for rootwait timeout parameter
vfs: fix up the assert in i_readcount_dec
fs: Fix one kernel-doc comment
docs: filesystems: idmappings: clarify from where idmappings are taken
fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs
vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull libfs and tmpfs updates from Christian Brauner:
"This cycle saw a lot of work for tmpfs that required changes to the
vfs layer. Andrew, Hugh, and I decided to take tmpfs through vfs this
cycle. Things will go back to mm next cycle.
Features
========
- By far the biggest work is the quota support for tmpfs. New tmpfs
quota infrastructure is added to support it and a new QFMT_SHMEM
uapi option is exposed.
This offers user and group quotas to tmpfs (project quotas will be
added later). Similar to other filesystems tmpfs quota are not
supported within user namespaces yet.
- Add support for user xattrs. While tmpfs already supports security
xattrs (security.*) and POSIX ACLs for a long time it lacked
support for user xattrs (user.*). With this pull request tmpfs will
be able to support a limited number of user xattrs.
This is accompanied by a fix (see below) to limit persistent simple
xattr allocations.
- Add support for stable directory offsets. Currently tmpfs relies on
the libfs provided cursor-based mechanism for readdir. This causes
issues when a tmpfs filesystem is exported via NFS.
NFS clients do not open directories. Instead, each server-side
readdir operation opens the directory, reads it, and then closes
it. Since the cursor state for that directory is associated with
the opened file it is discarded after each readdir operation. Such
directory offsets are not just cached by NFS clients but also
various userspace libraries based on these clients.
As it stands there is no way to invalidate the caches when
directory offsets have changed and the whole application depends on
unchanging directory offsets.
At LSFMM we discussed how to solve this problem and decided to
support stable directory offsets. libfs now allows filesystems like
tmpfs to use an xarrary to map a directory offset to a dentry. This
mechanism is currently only used by tmpfs but can be supported by
others as well.
Fixes
=====
- Change persistent simple xattrs allocations in libfs from
GFP_KERNEL to GPF_KERNEL_ACCOUNT so they're subject to memory
cgroup limits. Since this is a change to libfs it affects both
tmpfs and kernfs.
- Correctly verify {g,u}id mount options.
A new filesystem context is created via fsopen() which records the
namespace that becomes the owning namespace of the superblock when
fsconfig(FSCONFIG_CMD_CREATE) is called for filesystems that are
mountable in namespaces. However, fsconfig() calls can occur in a
namespace different from the namespace where fsopen() has been
called.
Currently, when fsconfig() is called to set {g,u}id mount options
the requested {g,u}id is mapped into a k{g,u}id according to the
namespace where fsconfig() was called from. The resulting k{g,u}id
is not guaranteed to be resolvable in the namespace of the
filesystem (the one that fsopen() was called in).
This means it's possible for an unprivileged user to create files
owned by any group in a tmpfs mount since it's possible to set the
setid bits on the tmpfs directory.
The contract for {g,u}id mount options and {g,u}id values in
general set from userspace has always been that they are translated
according to the caller's idmapping. In so far, tmpfs has been
doing the correct thing. But since tmpfs is mountable in
unprivileged contexts it is also necessary to verify that the
resulting {k,g}uid is representable in the namespace of the
superblock to avoid such bugs.
The new mount api's cross-namespace delegation abilities are
already widely used. Having talked to a bunch of userspace this is
the most faithful solution with minimal regression risks"
* tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs
mm: invalidation check mapping before folio_contains
tmpfs: trivial support for direct IO
tmpfs,xattr: enable limited user extended attributes
tmpfs: track free_ispace instead of free_inodes
xattr: simple_xattr_set() return old_xattr to be freed
tmpfs: verify {g,u}id mount options correctly
shmem: move spinlock into shmem_recalc_inode() to fix quota support
libfs: Remove parent dentry locking in offset_iterate_dir()
libfs: Add a lock class for the offset map's xa_lock
shmem: stable directory offsets
shmem: Refactor shmem_symlink()
libfs: Add directory operations for stable offsets
shmem: fix quota lock nesting in huge hole handling
shmem: Add default quota limit mount options
shmem: quota support
shmem: prepare shmem quota infrastructure
quota: Check presence of quota operation structures instead of ->quota_read and ->quota_write callbacks
shmem: make shmem_get_inode() return ERR_PTR instead of NULL
shmem: make shmem_inode_acct_block() return error
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Now that neither ext4 nor f2fs allows inodes with the casefold flag to
be instantiated when unsupported, it's unnecessary to repeatedly check
for support later on during random filesystem operations.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230814182903.37267-4-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Remove a number of implicit calls to compound_head() and various calls
to compatibility functions. This is not sufficient to enable support
for large folios; generic_perform_write() must be converted first.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Message-Id: <20230821141322.2535459-1-willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Since offset_iterate_dir() does not walk the parent's d_subdir list
nor does it manipulate the parent's d_child, there doesn't seem to
be a reason to hold the parent's d_lock. The offset_ctx's xarray can
be sufficiently protected with just the RCU read lock.
Flame graph data captured during the git regression run shows a
20% reduction in CPU cycles consumed in offset_find_next().
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202307171640.e299f8d5-oliver.sang@intel.com
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Message-Id: <169030957098.157536.9938425508695693348.stgit@manet.1015granger.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Tie the dynamically-allocated xarray locks into a single class so
contention on the directory offset xarrays can be observed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Message-Id: <169020933088.160441.9405180953116076087.stgit@manet.1015granger.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Create a vector of directory operations in fs/libfs.c that handles
directory seeks and readdir via stable offsets instead of the
current cursor-based mechanism.
For the moment these are unused.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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generic_fillattr just fills in the entire stat struct indiscriminately
today, copying data from the inode. There is at least one attribute
(STATX_CHANGE_COOKIE) that can have side effects when it is reported,
and we're looking at adding more with the addition of multigrain
timestamps.
Add a request_mask argument to generic_fillattr and have most callers
just pass in the value that is passed to getattr. Have other callers
(e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of
STATX_CHANGE_COOKIE into generic_fillattr.
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: "Paulo Alcantara (SUSE)" <pc@manguebit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-54-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
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The interface for fcntl expects the argument passed for the command
F_SETLEASE to be of type int. The current code wrongly treats it as
a long. In order to avoid access to undefined bits, we should explicitly
cast the argument to int.
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Laight <David.Laight@ACULAB.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-morello@op-lists.linaro.org
Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com>
Message-Id: <20230414152459.816046-3-Luca.Vizzarro@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
A rename potentially involves updating 4 different inode timestamps. Add
a function that handles the details sanely, and convert the libfs.c
callers to use it.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705185812.579118-3-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Add a helper dealing with handling the syncing of a buffered write
fallback for direct I/O.
Link: https://lkml.kernel.org/r/20230601145904.1385409-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There are three copies of the same dt_type helper sprinkled around the
tree. Convert them to use the common fs_umode_to_dtype function instead,
which has the added advantage of properly returning DT_UNKNOWN when
given a mode that contains an unrecognized type.
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Phillip Potter <phil@philpotter.co.uk>
Suggested-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <20230330104144.75547-1-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
introduce dedicated idmap type for mounts"). As promised in last
cycle's pull request message this converts everything to rely on
struct mnt_idmap.
Currently we still pass around the plain namespace that was attached
to a mount. This is in general pretty convenient but it makes it easy
to conflate namespaces that are relevant on the filesystem with
namespaces that are relevant on the mount level. Especially for
non-vfs developers without detailed knowledge in this area this was a
potential source for bugs.
This finishes the conversion. Instead of passing the plain namespace
around this updates all places that currently take a pointer to a
mnt_userns with a pointer to struct mnt_idmap.
Now that the conversion is done all helpers down to the really
low-level helpers only accept a struct mnt_idmap argument instead of
two namespace arguments.
Conflating mount and other idmappings will now cause the compiler to
complain loudly thus eliminating the possibility of any bugs. This
makes it impossible for filesystem developers to mix up mount and
filesystem idmappings as they are two distinct types and require
distinct helpers that cannot be used interchangeably.
Everything associated with struct mnt_idmap is moved into a single
separate file. With that change no code can poke around in struct
mnt_idmap. It can only be interacted with through dedicated helpers.
That means all filesystems are and all of the vfs is completely
oblivious to the actual implementation of idmappings.
We are now also able to extend struct mnt_idmap as we see fit. For
example, we can decouple it completely from namespaces for users that
don't require or don't want to use them at all. We can also extend
the concept of idmappings so we can cover filesystem specific
requirements.
In combination with the vfs{g,u}id_t work we finished in v6.2 this
makes this feature substantially more robust and thus difficult to
implement wrong by a given filesystem and also protects the vfs.
- Enable idmapped mounts for tmpfs and fulfill a longstanding request.
A long-standing request from users had been to make it possible to
create idmapped mounts for tmpfs. For example, to share the host's
tmpfs mount between multiple sandboxes. This is a prerequisite for
some advanced Kubernetes cases. Systemd also has a range of use-cases
to increase service isolation. And there are more users of this.
However, with all of the other work going on this was way down on the
priority list but luckily someone other than ourselves picked this
up.
As usual the patch is tiny as all the infrastructure work had been
done multiple kernel releases ago. In addition to all the tests that
we already have I requested that Rodrigo add a dedicated tmpfs
testsuite for idmapped mounts to xfstests. It is to be included into
xfstests during the v6.3 development cycle. This should add a slew of
additional tests.
* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
shmem: support idmapped mounts for tmpfs
fs: move mnt_idmap
fs: port vfs{g,u}id helpers to mnt_idmap
fs: port fs{g,u}id helpers to mnt_idmap
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
fs: port i_{g,u}id_{needs_}update() to mnt_idmap
quota: port to mnt_idmap
fs: port privilege checking helpers to mnt_idmap
fs: port inode_owner_or_capable() to mnt_idmap
fs: port inode_init_owner() to mnt_idmap
fs: port acl to mnt_idmap
fs: port xattr to mnt_idmap
fs: port ->permission() to pass mnt_idmap
fs: port ->fileattr_set() to pass mnt_idmap
fs: port ->set_acl() to pass mnt_idmap
fs: port ->get_acl() to pass mnt_idmap
fs: port ->tmpfile() to pass mnt_idmap
fs: port ->rename() to pass mnt_idmap
fs: port ->mknod() to pass mnt_idmap
fs: port ->mkdir() to pass mnt_idmap
...
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|
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
|
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Patch series "fix error when writing negative value to simple attribute
files".
The simple attribute files do not accept a negative value since the commit
488dac0c9237 ("libfs: fix error cast of negative value in
simple_attr_write()"), but some attribute files want to accept a negative
value.
This patch (of 3):
The simple attribute files do not accept a negative value since the commit
488dac0c9237 ("libfs: fix error cast of negative value in
simple_attr_write()"), so we have to use a 64-bit value to write a
negative value.
This adds DEFINE_SIMPLE_ATTRIBUTE_SIGNED for a signed value.
Link: https://lkml.kernel.org/r/20220919172418.45257-1-akinobu.mita@gmail.com
Link: https://lkml.kernel.org/r/20220919172418.45257-2-akinobu.mita@gmail.com
Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It has many callsites and is large.
text data bss dec hex filename
91796 15984 512 108292 1a704 mm/shmem.o-before
91180 15984 512 107676 1a49c mm/shmem.o-after
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This is a full folio conversion; it is prepared to handle folios of
arbitrary size.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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There are no more aop flags left, so remove the parameter.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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There are no more aop flags left, so remove the parameter.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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This is a mechanical change.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
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We used to have to use noop_invalidatepage() to prevent
block_invalidatepage() from being called, but that behaviour is now gone.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
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Turn the CONFIG_UNICODE symbol into a tristate that generates some always
built in code and remove the confusing CONFIG_UNICODE_UTF8_DATA symbol.
Note that a lot of the IS_ENABLED() checks could be turned from cpp
statements into normal ifs, but this change is intended to be fairly
mechanic, so that should be cleaned up later.
Fixes: 2b3d04787012 ("unicode: Add utf8-data module")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
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Allow atomic exchange via RENAME_EXCHANGE when using simple_rename.
This affects binderfs, ramfs, hubetlbfs and bpffs.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20211028094724.59043-3-lmb@cloudflare.com
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Move shmem_exchange and make it available to other callers.
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20211028094724.59043-2-lmb@cloudflare.com
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Use __set_page_dirty_no_writeback() instead. This will set the dirty bit
on the page, which will be used to avoid calling set_page_dirty() in the
future. It will have no effect on actually writing the page back, as the
pages are not on any LRU lists.
[akpm@linux-foundation.org: export __set_page_dirty_no_writeback() to modules]
Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use __set_page_dirty_no_writeback() instead. This will set the dirty bit
on the page, which will be used to avoid calling set_page_dirty() in the
future. It will have no effect on actually writing the page back, as the
pages are not on any LRU lists.
Link: https://lkml.kernel.org/r/20210615162342.1669332-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Move the ramfs aops to libfs and reuse them for kernfs and configfs.
Thosw two did not wire up ->set_page_dirty before and now get
__set_page_dirty_no_writeback, which is the right one for no-writeback
address_space usage.
Drop the now unused exports of the libfs helpers only used for ramfs-style
pagecache usage.
Link: https://lkml.kernel.org/r/20210614061512.3966143-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix kernel-doc warning in libfs.c.
../fs/libfs.c:498: warning: Function parameter or member 'mnt_userns' not described in 'simple_setattr'
Link: https://lore.kernel.org/r/20210216042929.8931-2-rdunlap@infradead.org/
Fixes: 549c7297717c ("fs: make helpers idmap mount aware")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
"We've got a good handful of patches for SELinux this time around; with
everything passing the selinux-testsuite and applying cleanly to your
tree as of a few minutes ago. The highlights are:
- Add support for labeling anonymous inodes, and extend this new
support to userfaultfd.
- Fallback to SELinux genfs file labeling if the filesystem does not
have xattr support. This is useful for virtiofs which can vary in
its xattr support depending on the backing filesystem.
- Classify and handle MPTCP the same as TCP in SELinux.
- Ensure consistent behavior between inode_getxattr and
inode_listsecurity when the SELinux policy is not loaded. This
fixes a known problem with overlayfs.
- A couple of patches to prune some unused variables from the SELinux
code, mark private variables as static, and mark other variables as
__ro_after_init or __read_mostly"
* tag 'selinux-pr-20210215' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
fs: anon_inodes: rephrase to appropriate kernel-doc
userfaultfd: use secure anon inodes for userfaultfd
selinux: teach SELinux about anonymous inodes
fs: add LSM-supporting anon-inode interface
security: add inode_init_security_anon() LSM hook
selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support
selinux: mark selinux_xfrm_refcount as __read_mostly
selinux: mark some global variables __ro_after_init
selinux: make selinuxfs_mount static
selinux: drop the unnecessary aurule_callback variable
selinux: remove unused global variables
selinux: fix inconsistency between inode_getxattr and inode_listsecurity
selinux: handle MPTCP consistently with TCP
|
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Pull core block updates from Jens Axboe:
"Another nice round of removing more code than what is added, mostly
due to Christoph's relentless pursuit of tech debt removal/cleanups.
This pull request contains:
- Two series of BFQ improvements (Paolo, Jan, Jia)
- Block iov_iter improvements (Pavel)
- bsg error path fix (Pan)
- blk-mq scheduler improvements (Jan)
- -EBUSY discard fix (Jan)
- bvec allocation improvements (Ming, Christoph)
- bio allocation and init improvements (Christoph)
- Store bdev pointer in bio instead of gendisk + partno (Christoph)
- Block trace point cleanups (Christoph)
- hard read-only vs read-only split (Christoph)
- Block based swap cleanups (Christoph)
- Zoned write granularity support (Damien)
- Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)"
* tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits)
mm: simplify swapdev_block
sd_zbc: clear zone resources for non-zoned case
block: introduce blk_queue_clear_zone_settings()
zonefs: use zone write granularity as block size
block: introduce zone_write_granularity limit
block: use blk_queue_set_zoned in add_partition()
nullb: use blk_queue_set_zoned() to setup zoned devices
nvme: cleanup zone information initialization
block: document zone_append_max_bytes attribute
block: use bi_max_vecs to find the bvec pool
md/raid10: remove dead code in reshape_request
block: mark the bio as cloned in bio_iov_bvec_set
block: set BIO_NO_PAGE_REF in bio_iov_bvec_set
block: remove a layer of indentation in bio_iov_iter_get_pages
block: turn the nr_iovecs argument to bio_alloc* into an unsigned short
block: remove the 1 and 4 vec bvec_slabs entries
block: streamline bvec_alloc
block: factor out a bvec_alloc_gfp helper
block: move struct biovec_slab to bio.c
block: reuse BIO_INLINE_VECS for integrity bvecs
...
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Now that generic_set_encrypted_ci_d_ops() has been added and ext4 and
f2fs are using it, it's no longer necessary to export
generic_ci_d_compare() and generic_ci_d_hash() to filesystems.
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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There is no point in allocating memory for a synchronous flush.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
|
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The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
|
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When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
|
|
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
|
|
This change adds a new function, anon_inode_getfd_secure, that creates
anonymous-node file with individual non-S_PRIVATE inode to which security
modules can apply policy. Existing callers continue using the original
singleton-inode kind of anonymous-inode file. We can transition anonymous
inode users to the new kind of anonymous inode in individual patches for
the sake of bisection and review.
The new function accepts an optional context_inode parameter that callers
can use to provide additional contextual information to security modules.
For example, in case of userfaultfd, the created inode is a 'logical child'
of the context_inode (userfaultfd inode of the parent process) in the sense
that it provides the security context required during creation of the child
process' userfaultfd inode.
Signed-off-by: Daniel Colascione <dancol@google.com>
[LG: Delete obsolete comments to alloc_anon_inode()]
[LG: Add context_inode description in comments to anon_inode_getfd_secure()]
[LG: Remove definition of anon_inode_getfile_secure() as there are no callers]
[LG: Make __anon_inode_getfile() static]
[LG: Use correct error cast in __anon_inode_getfile()]
[LG: Fix error handling in __anon_inode_getfile()]
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've made more work into per-file compression support.
For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to
change the algorithm or cluster size per file. F2FS_IOC_COMPRESS |
DECOMPRESS_FILE provides a way to compress and decompress the existing
normal files manually.
There is also a new mount option, compress_mode=fs|user, which can
control who compresses the data.
Chao also added a checksum feature with a mount option so that
we are able to detect any corrupted cluster.
In addition, Daniel contributed casefolding with encryption patch,
which will be used for Android devices.
Summary:
Enhancements:
- add ioctls and mount option to manage per-file compression feature
- support casefolding with encryption
- support checksum for compressed cluster
- avoid IO starvation by replacing mutex with rwsem
- add sysfs, max_io_bytes, to control max bio size
Bug fixes:
- fix use-after-free issue when compression and fsverity are enabled
- fix consistency corruption during fault injection test
- fix data offset for lseek
- get rid of buffer_head which has 32bits limit in fiemap
- fix some bugs in multi-partitions support
- fix nat entry count calculation in shrinker
- fix some stat information
And, we've refactored some logics and fix minor bugs as well"
* tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits)
f2fs: compress: fix compression chksum
f2fs: fix shift-out-of-bounds in sanity_check_raw_super()
f2fs: fix race of pending_pages in decompression
f2fs: fix to account inline xattr correctly during recovery
f2fs: inline: fix wrong inline inode stat
f2fs: inline: correct comment in f2fs_recover_inline_data
f2fs: don't check PAGE_SIZE again in sanity_check_raw_super()
f2fs: convert to F2FS_*_INO macro
f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size
f2fs: don't allow any writes on readonly mount
f2fs: avoid race condition for shrinker count
f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
f2fs: add compress_mode mount option
f2fs: Remove unnecessary unlikely()
f2fs: init dirty_secmap incorrectly
f2fs: remove buffer_head which has 32bits limit
f2fs: fix wrong block count instead of bytes
f2fs: use new conversion functions between blks and bytes
f2fs: rename logical_to_blk and blk_to_logical
f2fs: fix kbytes written stat for multi-device case
...
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This adds a function to set dentry operations at lookup time that will
work for both encrypted filenames and casefolded filenames.
A filesystem that supports both features simultaneously can use this
function during lookup preparations to set up its dentry operations once
fscrypt no longer does that itself.
Currently the casefolding dentry operation are always set if the
filesystem defines an encoding because the features is toggleable on
empty directories. Unlike in the encryption case, the dentry operations
used come from the parent. Since we don't know what set of functions
we'll eventually need, and cannot change them later, we enable the
casefolding operations if the filesystem supports them at all.
By splitting out the various cases, we support as few dentry operations
as we can get away with, maximizing compatibility with overlayfs, which
will not function if a filesystem supports certain dentry_operations.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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The attr->set() receive a value of u64, but simple_strtoll() is used for
doing the conversion. It will lead to the error cast if user inputs a
negative value.
Use kstrtoull() instead of simple_strtoll() to convert a string got from
the user to an unsigned value. The former will return '-EINVAL' if it
gets a negetive value, but the latter can't handle the situation
correctly. Make 'val' unsigned long long as what kstrtoull() takes,
this will eliminate the compile warning on no 64-bit architectures.
Fixes: f7b88631a897 ("fs/libfs.c: fix simple_attr_write() on 32bit machines")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/1605341356-11872-1-git-send-email-yangyicong@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This adds general supporting functions for filesystems that use
utf8 casefolding. It provides standard dentry_operations and adds the
necessary structures in struct super_block to allow this standardization.
The new dentry operations are functionally equivalent to the existing
operations in ext4 and f2fs, apart from the use of utf8_casefold_hash to
avoid an allocation.
By providing a common implementation, all users can benefit from any
optimizations without needing to port over improvements.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
|
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Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.
[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
|
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The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Reading from a debugfs file at a nonzero position, without first reading
at position 0, leaks uninitialized memory to userspace.
It's a bit tricky to do this, since lseek() and pread() aren't allowed
on these files, and write() doesn't update the position on them. But
writing to them with splice() *does* update the position:
#define _GNU_SOURCE 1
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
int main()
{
int pipes[2], fd, n, i;
char buf[32];
pipe(pipes);
write(pipes[1], "0", 1);
fd = open("/sys/kernel/debug/fault_around_bytes", O_RDWR);
splice(pipes[0], NULL, fd, NULL, 1, 0);
n = read(fd, buf, sizeof(buf));
for (i = 0; i < n; i++)
printf("%02x", buf[i]);
printf("\n");
}
Output:
5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a30
Fix the infoleak by making simple_attr_read() always fill
simple_attr::get_buf if it hasn't been filled yet.
Reported-by: syzbot+fcab69d1ada3e8d6f06b@syzkaller.appspotmail.com
Reported-by: Alexander Potapenko <glider@google.com>
Fixes: acaefc25d21f ("[PATCH] libfs: add simple attribute files")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200308023849.988264-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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two requirements: no file creations in IS_DEADDIR and no cross-directory
renames whatsoever.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Fix kernel-doc warning in fs/libfs.c:
fs/libfs.c:496: warning: Excess function parameter 'available' description in 'simple_write_end'
Link: http://lkml.kernel.org/r/5fc9d70b-e377-0ec9-066a-970d49579041@infradead.org
Fixes: ad2a722f196d ("libfs: Open code simple_commit_write into only user")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Boaz Harrosh <boazh@netapp.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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that eliminates the last place where we accessed the tail of ->d_subdirs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
There are two problems in dcache_readdir() - one is that lockless traversal
of the list needs non-trivial cooperation of d_alloc() (at least a switch
to list_add_rcu(), and probably more than just that) and another is that
it assumes that no removal will happen without the directory locked exclusive.
Said assumption had always been there, never had been stated explicitly and
is violated by several places in the kernel (devpts and selinuxfs).
* replacement of next_positive() with different calling conventions:
it returns struct list_head * instead of struct dentry *; the latter is
passed in and out by reference, grabbing the result and dropping the original
value.
* scan is under ->d_lock. If we run out of timeslice, cursor is moved
after the last position we'd reached and we reschedule; then the scan continues
from that place. To avoid livelocks between multiple lseek() (with cursors
getting moved past each other, never reaching the real entries) we always
skip the cursors, need_resched() or not.
* returned list_head * is either ->d_child of dentry we'd found or
->d_subdirs of parent (if we got to the end of the list).
* dcache_readdir() and dcache_dir_lseek() switched to new helper.
dcache_readdir() always holds a reference to dentry passed to dir_emit() now.
Cursor is moved to just before the entry where dir_emit() has failed or into
the very end of the list, if we'd run out.
* move_cursor() eliminated - it had sucky calling conventions and
after fixing that it became simply list_move() (in lseek and scan_positives)
or list_move_tail() (in readdir).
All operations with the list are under ->d_lock now, and we do not
depend upon having all file removals done with parent locked exclusive
anymore.
Cc: stable@vger.kernel.org
Reported-by: "zhengbin (A)" <zhengbin13@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
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counterpart of mount_nodev(). Switch hugetlb and pseudo to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
... now that all other callers are gone
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Provide a function, init_pseudo(), that provides a common
infrastructure for converting pseudo-filesystems that can never be
mountable.
[AV: once all users of mount_pseudo_xattr() get converted, it will be folded
into pseudo_fs_get_tree()]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-fsdevel@vger.kernel.org
|
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Once upon a time we used to set ->d_name of e.g. pipefs root
so that d_path() on pipes would work. These days it's
completely pointless - dentries of pipes are not even connected
to pipefs root. However, mount_pseudo() had set the root
dentry name (passed as the second argument) and callers
kept inventing names to pass to it. Including those that
didn't *have* any non-root dentries to start with...
All of that had been pointless for about 8 years now; it's
time to get rid of that cargo-culting...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
"Assorted stuff, with no common topic whatsoever..."
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
libfs: document simple_get_link()
Documentation/filesystems/Locking: fix ->get_link() prototype
Documentation/filesystems/vfs.txt: document how ->i_link works
Documentation/filesystems/vfs.txt: remove bogus "Last updated" date
fs: use timespec64 in relatime_need_update
fs/block_dev.c: remove unused include
|
|
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch fixes the following warnings:
fs/affs/affs.h:124:38: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/configfs/dir.c:1692:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/configfs/dir.c:1694:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ceph/file.c:249:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/hash.c:233:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/hash.c:246:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext2/inode.c:1237:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext2/inode.c:1244:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1182:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1188:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1432:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ext4/indirect.c:1440:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/f2fs/node.c:618:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/f2fs/node.c:620:8: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/btrfs/ref-verify.c:522:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/gfs2/bmap.c:711:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/gfs2/bmap.c:722:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/jffs2/fs.c:339:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/nfsd/nfs4proc.c:429:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ufs/util.h:62:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/ufs/util.h:43:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/fcntl.c:770:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/seq_file.c:319:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/libfs.c:148:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/libfs.c:150:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/signalfd.c:178:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
fs/locks.c:1473:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
Warning level 3 was used: -Wimplicit-fallthrough=3
This patch is part of the ongoing efforts to enabling
-Wimplicit-fallthrough.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
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In preparation for the dax implementation to start associating dax pages
to inodes via page->mapping, we need to provide a 'struct
address_space_operations' instance for dax. Define some generic VFS aops
helpers for dax. These noop implementations are there in the dax case to
prevent the VFS from falling back to operations with page-cache
assumptions, dax_writeback_mapping_range() may not be referenced in the
FS_DAX=n case.
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Matthew Wilcox <mawilcox@microsoft.com>
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
|
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Many simple, block-based filesystems use generic_file_fsync as their
fsync operation. Some others (ext* and fat) also call this function
to handle syncing out data.
Switch this code over to use errseq_t based error reporting so that
all of these filesystems get reliable error reporting via fsync,
fdatasync and msync.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
|
|
ext2 currently does a test+clear of the AS_EIO flag, which is
is problematic for some coming changes.
What we really need to do instead is call filemap_check_errors
in __generic_file_fsync after syncing out the buffers. That
will be sufficient for this case, and help other callers detect
these errors properly as well.
With that, we don't need to twiddle it in ext2.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
|
|
simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory. Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs 'statx()' update from Al Viro.
This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.
It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?
From David Howells.
Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:
https://www.spinics.net/lists/linux-fsdevel/msg33831.html
* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
statx: Add a system call to make enhanced file info available
|
|
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Add #include <linux/cred.h> dependencies to all .c files rely on sched.h
doing that for them.
Note that even if the count where we need to add extra headers seems high,
it's still a net win, because <linux/sched.h> is included in over
2,200 files ...
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
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Add MS_KERNMOUNT to the flags that are passed.
Use sget_userns and force &init_user_ns instead of calling sget so that
even if called from a weird context the internal filesystem will be
considered to be in the intial user namespace.
Luis Ressel reported that the the failure to pass MS_KERNMOUNT into
mount_pseudo broke his in development graphics driver that uses the
generic drm infrastructure. I am not certain the deriver was bug
free in it's usage of that infrastructure but since
mount_pseudo_xattr can never be triggered by userspace it is clearer
and less error prone, and less problematic for the code to be explicit.
Reported-by: Luis Ressel <aranea@aixah.de>
Tested-by: Luis Ressel <aranea@aixah.de>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
|
|
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull partial readlink cleanups from Miklos Szeredi.
This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.
Miklos and Al are still discussing the rest of the series.
* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
vfs: make generic_readlink() static
vfs: remove ".readlink = generic_readlink" assignments
vfs: default to generic_readlink()
vfs: replace calling i_op->readlink with vfs_readlink()
proc/self: use generic_readlink
ecryptfs: use vfs_get_link()
bad_inode: add missing i_op initializers
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
If .readlink == NULL implies generic_readlink().
Generated by:
to_del="\.readlink.*=.*generic_readlink"
for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
|
|
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs xattr updates from Al Viro:
"xattr stuff from Andreas
This completes the switch to xattr_handler ->get()/->set() from
->getxattr/->setxattr/->removexattr"
* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Remove {get,set,remove}xattr inode operations
xattr: Stop calling {get,set,remove}xattr inode operations
vfs: Check for the IOP_XATTR flag in listxattr
xattr: Add __vfs_{get,set,remove}xattr helpers
libfs: Use IOP_XATTR flag for empty directory handling
vfs: Use IOP_XATTR flag for bad-inode handling
vfs: Add IOP_XATTR inode operations flag
vfs: Move xattr_resolve_name to the front of fs/xattr.c
ecryptfs: Switch to generic xattr handlers
sockfs: Get rid of getxattr iop
sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
kernfs: Switch to generic xattr handlers
hfs: Switch to generic xattr handlers
jffs2: Remove jffs2_{get,set,remove}xattr macros
xattr: Remove unnecessary NULL attribute name check
|
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Instead of special xattr inode operations, use the IOP_XATTR inode
operations flag for the special libfs empty directories.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
If we allow pseudo-filesystems created with mount_pseudo to have xattr
handlers, we can replace sockfs_getxattr with a sockfs_xattr_get handler
to use the xattr handler name parsing.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.
CURRENT_TIME is also not y2038 safe.
This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.
Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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This is trivial to do:
- add flags argument to simple_rename()
- check if flags doesn't have any other than RENAME_NOREPLACE
- assign simple_rename() to .rename2 instead of .rename
Filesystems converted:
hugetlbfs, ramfs, bpf.
Debugfs uses simple_rename() to implement debugfs_rename(), which is for
debugfs instances to rename files internally, not for userspace filesystem
access. For this case pass zero flags to simple_rename().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
|
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inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Return nth positive child after given or NULL if there's
less than n left. dcache_readdir() and dcache_dir_lseek()
switched to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Make sure that directory is locked shared in dcache_dir_lseek();
for dcache_readdir() it's already tru, and that's enough to make
simple_positive() stable.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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d_walk() relies upon the tree not getting rearranged under it without
rename_lock being touched. And we do grab rename_lock around the
places that change the tree topology. Unfortunately, branch reordering
is just as bad from d_walk() POV and we have two places that do it
without touching rename_lock - one in handling of cursors (for ramfs-style
directories) and another in autofs. autofs one is a separate story; this
commit deals with the cursors.
* mark cursor dentries explicitly at allocation time
* make __dentry_kill() leave ->d_child.next pointing to the next
non-cursor sibling, making sure that it won't be moved around unnoticed
before the parent is relocked on ascend-to-parent path in d_walk().
* make d_walk() skip cursors explicitly; strictly speaking it's
not necessary (all callbacks we pass to d_walk() are no-ops on cursors),
but it makes analysis easier.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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no need to lock directory in dcache_dir_lseek(), while we are
at it - per-struct file exclusion is enough.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The rest of work.xattr stuff isn't needed for this branch
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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all callers are better off with kfree_put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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new method: ->get_link(); replacement of ->follow_link(). The differences
are:
* inode and dentry are passed separately
* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.
It's a flagday change - the old method is gone, all in-tree instances
converted. Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode. That'll change
in the next commits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Before the make_empty_dir_inode calls were introduce into proc, sysfs,
and sysctl those directories when stated reported an i_size of 0.
make_empty_dir_inode started reporting an i_size of 2. At least one
userspace application depended on stat returning i_size of 0. So
modify make_empty_dir_inode to cause an i_size of 0 to be reported for
these directories.
Cc: stable@vger.kernel.org
Reported-by: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
"Assorted VFS fixes and related cleanups (IMO the most interesting in
that part are f_path-related things and Eric's descriptor-related
stuff). UFS regression fixes (it got broken last cycle). 9P fixes.
fs-cache series, DAX patches, Jan's file_remove_suid() work"
[ I'd say this is much more than "fixes and related cleanups". The
file_table locking rule change by Eric Dumazet is a rather big and
fundamental update even if the patch isn't huge. - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
9p: cope with bogus responses from server in p9_client_{read,write}
p9_client_write(): avoid double p9_free_req()
9p: forgetting to cancel request on interrupted zero-copy RPC
dax: bdev_direct_access() may sleep
block: Add support for DAX reads/writes to block devices
dax: Use copy_from_iter_nocache
dax: Add block size note to documentation
fs/file.c: __fget() and dup2() atomicity rules
fs/file.c: don't acquire files->file_lock in fd_install()
fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
vfs: avoid creation of inode number 0 in get_next_ino
namei: make set_root_rcu() return void
make simple_positive() public
ufs: use dir_pages instead of ufs_dir_pages()
pagemap.h: move dir_pages() over there
remove the pointless include of lglock.h
fs: cleanup slight list_entry abuse
xfs: Correctly lock inode when removing suid and file capabilities
fs: Call security_ops->inode_killpriv on truncate
fs: Provide function telling whether file_remove_privs() will do anything
...
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.
Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.
There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.
This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.
This set of changes also addresses an issue with how open file
descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of
/proc/<pid>/fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.
There is also a short list of issues that have not been fixed yet that
I will mention briefly.
It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.
As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
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To ensure it is safe to mount proc and sysfs I need to check if
filesystems that are mounted on top of them are mounted on truly empty
directories. Given that some directories can gain entries over time,
knowing that a directory is empty right now is insufficient.
Therefore add supporting infrastructure for permantently empty
directories that proc and sysfs can use when they create mount points
for filesystems and fs_fully_visible can use to test for permanently
empty directories to ensure that nothing will be gained by mounting a
fresh copy of proc or sysfs.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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similar to kfree_put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks. Stored pointer
is ignored in all cases except the last one.
Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().
b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is. In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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let "fast" symlinks store the pointer to the body into ->i_link and
use simple_follow_link for ->follow_link()
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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library helpers called by filesystem drivers on their own inodes
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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