From: Dave Chinner dchinner@redhat.com
[ Upstream commit 5e672cd69f0a534a445df4372141fd0d1d00901d ]
The current blocking mechanism for pushing the inodegc queue out to disk can result in systems becoming unusable when there is a long running inodegc operation. This is because the statfs() implementation currently issues a blocking flush of the inodegc queue and a significant number of common system utilities will call statfs() to discover something about the underlying filesystem.
This can result in userspace operations getting stuck on inodegc progress, and when trying to remove a heavily reflinked file on slow storage with a full journal, this can result in delays measuring in hours.
Avoid this problem by adding "push" function that expedites the flushing of the inodegc queue, but doesn't wait for it to complete.
Convert xfs_fs_statfs() and xfs_qm_scall_getquota() to use this mechanism so they don't block but still ensure that queued operations are expedited.
Fixes: ab23a7768739 ("xfs: per-cpu deferred inode inactivation queues") Reported-by: Chris Dunlop chris@onthe.net.au Signed-off-by: Dave Chinner dchinner@redhat.com [djwong: fix _getquota_next to use _inodegc_push too] Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/xfs_icache.c | 20 +++++++++++++++----- fs/xfs/xfs_icache.h | 1 + fs/xfs/xfs_qm_syscalls.c | 9 ++++++--- fs/xfs/xfs_super.c | 7 +++++-- fs/xfs/xfs_trace.h | 1 + 5 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 2c3ef553f5ef..e9ebfe6f8015 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -1872,19 +1872,29 @@ xfs_inodegc_worker( }
/* - * Force all currently queued inode inactivation work to run immediately and - * wait for the work to finish. + * Expedite all pending inodegc work to run immediately. This does not wait for + * completion of the work. */ void -xfs_inodegc_flush( +xfs_inodegc_push( struct xfs_mount *mp) { if (!xfs_is_inodegc_enabled(mp)) return; + trace_xfs_inodegc_push(mp, __return_address); + xfs_inodegc_queue_all(mp); +}
+/* + * Force all currently queued inode inactivation work to run immediately and + * wait for the work to finish. + */ +void +xfs_inodegc_flush( + struct xfs_mount *mp) +{ + xfs_inodegc_push(mp); trace_xfs_inodegc_flush(mp, __return_address); - - xfs_inodegc_queue_all(mp); flush_workqueue(mp->m_inodegc_wq); }
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h index 2e4cfddf8b8e..6cd180721659 100644 --- a/fs/xfs/xfs_icache.h +++ b/fs/xfs/xfs_icache.h @@ -76,6 +76,7 @@ void xfs_blockgc_stop(struct xfs_mount *mp); void xfs_blockgc_start(struct xfs_mount *mp);
void xfs_inodegc_worker(struct work_struct *work); +void xfs_inodegc_push(struct xfs_mount *mp); void xfs_inodegc_flush(struct xfs_mount *mp); void xfs_inodegc_stop(struct xfs_mount *mp); void xfs_inodegc_start(struct xfs_mount *mp); diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c index 47fe60e1a887..322a111dfbc0 100644 --- a/fs/xfs/xfs_qm_syscalls.c +++ b/fs/xfs/xfs_qm_syscalls.c @@ -481,9 +481,12 @@ xfs_qm_scall_getquota( struct xfs_dquot *dqp; int error;
- /* Flush inodegc work at the start of a quota reporting scan. */ + /* + * Expedite pending inodegc work at the start of a quota reporting + * scan but don't block waiting for it to complete. + */ if (id == 0) - xfs_inodegc_flush(mp); + xfs_inodegc_push(mp);
/* * Try to get the dquot. We don't want it allocated on disk, so don't @@ -525,7 +528,7 @@ xfs_qm_scall_getquota_next(
/* Flush inodegc work at the start of a quota reporting scan. */ if (*id == 0) - xfs_inodegc_flush(mp); + xfs_inodegc_push(mp);
error = xfs_qm_dqget_next(mp, *id, type, &dqp); if (error) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 8fe6ca9208de..9b3af7611eaa 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -795,8 +795,11 @@ xfs_fs_statfs( xfs_extlen_t lsize; int64_t ffree;
- /* Wait for whatever inactivations are in progress. */ - xfs_inodegc_flush(mp); + /* + * Expedite background inodegc but don't wait. We do not want to block + * here waiting hours for a billion extent file to be truncated. + */ + xfs_inodegc_push(mp);
statp->f_type = XFS_SUPER_MAGIC; statp->f_namelen = MAXNAMELEN - 1; diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 1033a95fbf8e..ebd17ddba024 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -240,6 +240,7 @@ DEFINE_EVENT(xfs_fs_class, name, \ TP_PROTO(struct xfs_mount *mp, void *caller_ip), \ TP_ARGS(mp, caller_ip)) DEFINE_FS_EVENT(xfs_inodegc_flush); +DEFINE_FS_EVENT(xfs_inodegc_push); DEFINE_FS_EVENT(xfs_inodegc_start); DEFINE_FS_EVENT(xfs_inodegc_stop); DEFINE_FS_EVENT(xfs_inodegc_queue);