[PATCH V3 0/9] Fixes to the previously-merged drivers/dax/fsdev series

[John Groves]

From: John Groves <john@xxxxxxxxxx>

This series applies bug fixes (mostly found via sashiko) to the dax/fsdev 
series. This has been soaking in the famfs CI pipeline for 2+ weeks and
1) won't affect anything that doesn't use drivers/dax/fsdev.c, and 2)
doesn't affect any known workloads - although the bugs would have 
manifested when multi-range DCD dax devices are a thing (soon-ish).

Changes since V2:

* Patch 1 (comment fix): No change. Responded to Dave's question about
  the dropped precondition -- the new comment correctly covers both
  callers; fsdev_clear_folio_state() does not guarantee share==0 before
  calling, so the old precondition was no longer universally true.
* V2 patch 2 (three fixes): Split into three separate patches (patches
  2-4) per Dave's review.
* V2 patch 3 (two fixes): Split into two separate patches (patches 5-6)
  per Dave's review.
* V2 patch 4 (clamp direct_access / remove cached_size): Dropped.
  Dave's analysis correctly showed the claimed bug does not exist --
  dax_pgoff_to_phys() already enforces that the full requested size fits
  within a single range before returning, making the clamp a no-op in
  every reachable path.
* V2 patch 5 (holder_ops race): Use WRITE_ONCE() for the holder_ops
  store; add WARN_ON() on the cmpxchg result to catch wrong-holder and
  double-put API contract violations; fix the inline comment, which
  incorrectly claimed dax_holder_notify_failure() consults holder_ops
  only when holder_data is non-NULL.
* V2 patch 6 (dax_dev_find): Add dax_alive() check under dax_read_lock()
  after ilookup5() to prevent returning a device that is concurrently
  being torn down by kill_dax().
* V2 patch 7 (formatting cleanup): Drop incorrect Fixes: tag; add
  Dave's Reviewed-by.
* The series grows from 7 to 9 patches.

Changes since v1:
* Dropped modes from patch 6 to fs/fuse/famfs.c and 
  fs/famfs/famfs_inode.c, which are not upstream so it broke
  attempts to apply the series. Oops...
* Added patch 7, which addresses a previously-missed review comment
  from Jonathan - minor cleanup

John Groves (9):
  dax: fix misleading comment about share/index union in
    dax_folio_reset_order()
  dax/fsdev: fix multi-range offset in memory_failure handler
  dax/fsdev: clear vmemmap_shift when binding static pgmap
  dax/fsdev: clear dev_dax->pgmap on probe failure
  dax/fsdev: use __va(phys) for kaddr in direct_access
  dax/fsdev: fail probe on invalid pgmap offset
  dax: fix holder_ops race in fs_put_dax()
  dax: replace exported dax_dev_get() with non-allocating dax_dev_find()
  dax: fsdev.c minor formatting cleanup

 drivers/dax/fsdev.c | 81 +++++++++++++++++++++++++++++++--------------
 drivers/dax/super.c | 73 +++++++++++++++++++++++++++++++++++++---
 fs/dax.c            | 12 +++----
 include/linux/dax.h |  6 +++-
 4 files changed, 136 insertions(+), 36 deletions(-)

-- 
2.53.0