tree e98e3b0e4cee6b9a3d395b247d3e6a41b3619964
parent af49ad548b93659e243dedecf1432b0f5eba3844
author Omar Sandoval <osandov@fb.com> 1574816288 -0800
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1578824656 +0100

xfs: don't check for AG deadlock for realtime files in bunmapi

commit 69ffe5960df16938bccfe1b65382af0b3de51265 upstream.

Commit 5b094d6dac04 ("xfs: fix multi-AG deadlock in xfs_bunmapi") added
a check in __xfs_bunmapi() to stop early if we would touch multiple AGs
in the wrong order. However, this check isn't applicable for realtime
files. In most cases, it just makes us do unnecessary commits. However,
without the fix from the previous commit ("xfs: fix realtime file data
space leak"), if the last and second-to-last extents also happen to have
different "AG numbers", then the break actually causes __xfs_bunmapi()
to return without making any progress, which sends
xfs_itruncate_extents_flags() into an infinite loop.

Fixes: 5b094d6dac04 ("xfs: fix multi-AG deadlock in xfs_bunmapi")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>