[PATCH v3 0/2] ceph: fix client race conditions with stale r_parent

[Alex Markuze <amarkuze@redhat.com>]

This patch series addresses client-side race conditions in the Ceph filesystem
where the cached parent directory inode (r_parent) can become stale during
concurrent operations like rename, leading to incorrect state application.

The first patch adds validation during reply processing to ensure the cached
parent directory inode matches the directory info in MDS replies. It refactors
the path building API to use a structured approach and prevents applying state
changes to incorrect directory inodes.

The second patch addresses cases where r_parent becomes stale between request
creation and message sending when the parent directory's i_rwsem is not locked.
It validates that r_parent matches the encoded parent inode and updates to the
correct inode if a mismatch is detected, with appropriate warnings for this
rare but problematic condition.

Alex Markuze (2):
  ceph: fix client race condition validating r_parent before applying
    state
  ceph: fix client race condition where r_parent becomes stale before
    sending message

 fs/ceph/debugfs.c    |  14 ++--
 fs/ceph/dir.c        |  17 ++---
 fs/ceph/file.c       |  24 +++----
 fs/ceph/inode.c      |  59 +++++++++++++++--
 fs/ceph/mds_client.c | 148 +++++++++++++++++++++++++++----------------
 fs/ceph/mds_client.h |  12 +++-
 6 files changed, 182 insertions(+), 92 deletions(-)

-- 
2.34.1