[SRU][F][PATCH 0/1] xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()

[Kellen Renshaw]

Buglink: https://bugs.launchpad.net/bugs/1966803

SRU Justification:

[Impact]

* The xfs filesystem suffers from a deadlock issue in kernels < 5.5. This hangs IO to/from the affected filesystem. Sample backtraces added as a comment.

[Fix]

* 93597ae8dac0149b5c00b787cba6bf7ba213e666 93597ae8dac0 "xfs: Fix deadlock between AGI and AGF when target_ip exists in xfs_rename()"

* This is from the upstream 5.5 kernel.

[Test Plan]

* Set up an Ubuntu Bionic/Focal installation using kernel 5.4.

* Create and mount an XFS filesystem on a block device.

* Exercise the filesystem to verify that IO does not hang.

[Where problems could occur]

* This patch could cause locking issues on XFS filesystems, requiring a system restart to correct.

[Other Info]

* Bug is difficult to reproduce, a test kernel on affected systems with the above patch prevented the issue.

* Backports to earlier (4.15 and earlier) kernels have been omitted as the upstream patch does not apply cleanly and the issue has not been reproduced on them.

kaixuxia (1):
  xfs: Fix deadlock between AGI and AGF when target_ip exists in
    xfs_rename()

 fs/xfs/libxfs/xfs_dir2.h    |  2 ++
 fs/xfs/libxfs/xfs_dir2_sf.c | 28 +++++++++++++++++++++++-----
 fs/xfs/xfs_inode.c          | 17 +++++++++++++++++
 3 files changed, 42 insertions(+), 5 deletions(-)

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2.25.1