[PATCH v2 0/2] ext4: check return value of blkdev_issue_flush() in unchecked call sites

[guolingxing]

This series adds return value checks to the blkdev_issue_flush() call
sites in ext4 which ignore the return value: lazy inode table
initialization and the file system device flush issued before
starting a fast commit.  Both call sites also issue the flush without
checking the barrier mount option; the series makes them honor the
option, consistent with the other cache flushes in ext4 and jbd2.

Changes since v1:
- Drop the fast commit replay patch.  JBD2 already calls
  sync_blockdev() on the file system device, checks the device write
  error, and issues a final barrier-gated cache flush after journal
  and fast commit replay, and it propagates all of these errors to
  the mount.  The error check added by that patch was therefore
  redundant; the pre-existing per-inode flush in the replay path is
  left as is for now.
- Gate the remaining two cache flushes on the barrier mount option
  (JBD2_BARRIER for the fast commit path).  Checking the return value
  makes a cache flush failure fatal for lazy inode table
  initialization and fast commits; without the gating, this would
  regress file systems mounted with nobarrier on devices with failing
  cache flushes.
- Update the patch descriptions to describe the gating.

The patches are otherwise unchanged since v1.

guolingxing (2):
  ext4: check return value of blkdev_issue_flush() when initializing
    inode tables
  ext4: check return value of blkdev_issue_flush() when starting a fast
    commit

 fs/ext4/fast_commit.c | 8 ++++++--
 fs/ext4/ialloc.c      | 7 +++++--
 fs/ext4/super.c       | 3 ++-
 3 files changed, 13 insertions(+), 5 deletions(-)

-- 
2.34.1