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authorBrian Foster <bfoster@redhat.com>2020-04-12 13:11:10 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2020-04-13 08:00:19 -0700
commit4b674b9ac852937af1f8c62f730c325fb6eadcdb (patch)
treeed07e259fa8ee3e452121554fba4361764485998 /fs
parent8f3d9f354286745c751374f5f1fcafee6b3f3136 (diff)
xfs: acquire superblock freeze protection on eofblocks scans
The filesystem freeze sequence in XFS waits on any background eofblocks or cowblocks scans to complete before the filesystem is quiesced. At this point, the freezer has already stopped the transaction subsystem, however, which means a truncate or cowblock cancellation in progress is likely blocked in transaction allocation. This results in a deadlock between freeze and the associated scanner. Fix this problem by holding superblock write protection across calls into the block reapers. Since protection for background scans is acquired from the workqueue task context, trylock to avoid a similar deadlock between freeze and blocking on the write lock. Fixes: d6b636ebb1c9f ("xfs: halt auto-reclamation activities while rebuilding rmap") Reported-by: Paul Furtado <paulfurtado91@gmail.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_icache.c10
-rw-r--r--fs/xfs/xfs_ioctl.c5
2 files changed, 14 insertions, 1 deletions
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index a7be7a9e5c1a..8bf1d15be3f6 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -911,7 +911,12 @@ xfs_eofblocks_worker(
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_eofblocks_work);
+
+ if (!sb_start_write_trylock(mp->m_super))
+ return;
xfs_icache_free_eofblocks(mp, NULL);
+ sb_end_write(mp->m_super);
+
xfs_queue_eofblocks(mp);
}
@@ -938,7 +943,12 @@ xfs_cowblocks_worker(
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_cowblocks_work);
+
+ if (!sb_start_write_trylock(mp->m_super))
+ return;
xfs_icache_free_cowblocks(mp, NULL);
+ sb_end_write(mp->m_super);
+
xfs_queue_cowblocks(mp);
}
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index cdfb3cd9a25b..309958186d33 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -2363,7 +2363,10 @@ xfs_file_ioctl(
if (error)
return error;
- return xfs_icache_free_eofblocks(mp, &keofb);
+ sb_start_write(mp->m_super);
+ error = xfs_icache_free_eofblocks(mp, &keofb);
+ sb_end_write(mp->m_super);
+ return error;
}
default: