diff options
| author | Paulo Alcantara <pc@manguebit.org> | 2025-12-04 15:06:23 -0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2025-12-05 17:40:33 -0600 |
| commit | 855982a52ff7d188188f0ecf86c2ce95957202c6 (patch) | |
| tree | 62e0171cb5c5892abee05edfcb42eff211df3408 | |
| parent | 4ae4dde6f34a4124c65468ae4fa1f915fb40f900 (diff) | |
| download | tip-855982a52ff7d188188f0ecf86c2ce95957202c6.tar.gz | |
smb: client: relax session and tcon reconnect attempts
When the client re-establishes connection to the server, it will queue
a worker thread that will attempt to reconnect sessions and tcons on
every two seconds, which is kinda overkill as it is a very common
scenario when having expired passwords or KRB5 TGT tickets, or deleted
shares.
Use an exponential backoff strategy to handle session/tcon reconnect
attempts in the worker thread to prevent the client from overloading
the system when it is very unlikely to re-establish any session/tcon
soon while client is idle.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Pierguido Lambri <plambri@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/client/cifsglob.h | 21 | ||||
| -rw-r--r-- | fs/smb/client/connect.c | 4 | ||||
| -rw-r--r-- | fs/smb/client/smb2pdu.c | 6 |
3 files changed, 26 insertions, 5 deletions
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index f9c1f553ffd00c..3eca5bfb703030 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -745,6 +745,7 @@ struct TCP_Server_Info { struct session_key session_key; unsigned long lstrp; /* when we got last response from this server */ unsigned long neg_start; /* when negotiate started (jiffies) */ + unsigned long reconn_delay; /* when resched session and tcon reconnect */ struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */ #define CIFS_NEGFLAVOR_UNENCAP 1 /* wct == 17, but no ext_sec */ #define CIFS_NEGFLAVOR_EXTENDED 2 /* wct == 17, ext_sec bit set */ @@ -2292,4 +2293,24 @@ struct cifs_calc_sig_ctx { struct shash_desc *shash; }; +#define CIFS_RECONN_DELAY_SECS 30 +#define CIFS_MAX_RECONN_DELAY (4 * CIFS_RECONN_DELAY_SECS) + +static inline void cifs_queue_server_reconn(struct TCP_Server_Info *server) +{ + if (!delayed_work_pending(&server->reconnect)) { + WRITE_ONCE(server->reconn_delay, 0); + mod_delayed_work(cifsiod_wq, &server->reconnect, 0); + } +} + +static inline void cifs_requeue_server_reconn(struct TCP_Server_Info *server) +{ + unsigned long delay = READ_ONCE(server->reconn_delay); + + delay = umin(delay + CIFS_RECONN_DELAY_SECS, CIFS_MAX_RECONN_DELAY); + WRITE_ONCE(server->reconn_delay, delay); + queue_delayed_work(cifsiod_wq, &server->reconnect, delay * HZ); +} + #endif /* _CIFS_GLOB_H */ diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index cca6c722598d64..0d4f45444380f3 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -425,7 +425,7 @@ static int __cifs_reconnect(struct TCP_Server_Info *server, spin_unlock(&server->srv_lock); cifs_swn_reset_server_dstaddr(server); cifs_server_unlock(server); - mod_delayed_work(cifsiod_wq, &server->reconnect, 0); + cifs_queue_server_reconn(server); } } while (server->tcpStatus == CifsNeedReconnect); @@ -564,7 +564,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server) spin_unlock(&server->srv_lock); cifs_swn_reset_server_dstaddr(server); cifs_server_unlock(server); - mod_delayed_work(cifsiod_wq, &server->reconnect, 0); + cifs_queue_server_reconn(server); } while (server->tcpStatus == CifsNeedReconnect); dfs_cache_noreq_update_tgthint(ref_path, target_hint); diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index dec9968ffb4889..c9f437cd29a211 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -497,7 +497,7 @@ skip_add_channels: spin_unlock(&ses->ses_lock); if (smb2_command != SMB2_INTERNAL_CMD) - mod_delayed_work(cifsiod_wq, &server->reconnect, 0); + cifs_queue_server_reconn(server); atomic_inc(&tconInfoReconnectCount); out: @@ -4316,7 +4316,7 @@ void smb2_reconnect_server(struct work_struct *work) done: cifs_dbg(FYI, "Reconnecting tcons and channels finished\n"); if (resched) - queue_delayed_work(cifsiod_wq, &server->reconnect, 2 * HZ); + cifs_requeue_server_reconn(server); mutex_unlock(&pserver->reconnect_mutex); /* now we can safely release srv struct */ @@ -4340,7 +4340,7 @@ SMB2_echo(struct TCP_Server_Info *server) server->ops->need_neg(server)) { spin_unlock(&server->srv_lock); /* No need to send echo on newly established connections */ - mod_delayed_work(cifsiod_wq, &server->reconnect, 0); + cifs_queue_server_reconn(server); return rc; } spin_unlock(&server->srv_lock); |