diff options
| author | Christoph Hellwig <hch@lst.de> | 2017-07-18 20:16:51 +0200 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2017-07-26 17:20:03 +0200 |
| commit | 5b094d6dac0451ad89b1dc088395c7b399b7e9e8 (patch) | |
| tree | 83ef91fc22af5f57c4f08902ec92b3d432d0f1b9 /fs/xfs | |
| parent | xfs: check that dir block entries don't off the end of the buffer (diff) | |
| download | linux-5b094d6dac0451ad89b1dc088395c7b399b7e9e8.tar.xz linux-5b094d6dac0451ad89b1dc088395c7b399b7e9e8.zip | |
xfs: fix multi-AG deadlock in xfs_bunmapi
Just like in the allocator we must avoid touching multiple AGs out of
order when freeing blocks, as freeing still locks the AGF and can cause
the same AB-BA deadlocks as in the allocation path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index ee118ceb702f..c09c16b1ad3b 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -5435,6 +5435,7 @@ __xfs_bunmapi( xfs_fsblock_t sum; xfs_filblks_t len = *rlen; /* length to unmap in file */ xfs_fileoff_t max_len; + xfs_agnumber_t prev_agno = NULLAGNUMBER, agno; trace_xfs_bunmap(ip, bno, len, flags, _RET_IP_); @@ -5534,6 +5535,17 @@ __xfs_bunmapi( */ del = got; wasdel = isnullstartblock(del.br_startblock); + + /* + * Make sure we don't touch multiple AGF headers out of order + * in a single transaction, as that could cause AB-BA deadlocks. + */ + if (!wasdel) { + agno = XFS_FSB_TO_AGNO(mp, del.br_startblock); + if (prev_agno != NULLAGNUMBER && prev_agno > agno) + break; + prev_agno = agno; + } if (got.br_startoff < start) { del.br_startoff = start; del.br_blockcount -= start - got.br_startoff; |