Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:

 - Replace ext4's bmap and iopoll implementations to use iomap.

 - Clean up extent tree handling.

 - Other cleanups and miscellaneous bug fixes

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (31 commits)
  ext4: save all error info in save_error_info() and drop ext4_set_errno()
  ext4: fix incorrect group count in ext4_fill_super error message
  ext4: fix incorrect inodes per group in error message
  ext4: don't set dioread_nolock by default for blocksize < pagesize
  ext4: disable dioread_nolock whenever delayed allocation is disabled
  ext4: do not commit super on read-only bdev
  ext4: avoid ENOSPC when avoiding to reuse recently deleted inodes
  ext4: unregister sysfs path before destroying jbd2 journal
  ext4: check for non-zero journal inum in ext4_calculate_overhead
  ext4: remove map_from_cluster from ext4_ext_map_blocks
  ext4: clean up ext4_ext_insert_extent() call in ext4_ext_map_blocks()
  ext4: mark block bitmap corrupted when found instead of BUGON
  ext4: use flexible-array member for xattr structs
  ext4: use flexible-array member in struct fname
  Documentation: correct the description of FIEMAP_EXTENT_LAST
  ext4: move ext4_fiemap to use iomap framework
  ext4: make ext4_ind_map_blocks work with fiemap
  ext4: move ext4 bmap to use iomap infrastructure
  ext4: optimize ext4_ext_precache for 0 depth
  ext4: add IOMAP_F_MERGED for non-extent based mapping
  ...

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 27373f5792a4..e855d8260433 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -997,9 +997,10 @@ restart_loop:
 			 * journalled data) we need to unmap buffer and clear
 			 * more bits. We also need to be careful about the check
 			 * because the data page mapping can get cleared under
-			 * out hands, which alse need not to clear more bits
-			 * because the page and buffers will be freed and can
-			 * never be reused once we are done with them.
+			 * our hands. Note that if mapping == NULL, we don't
+			 * need to make buffer unmapped because the page is
+			 * already detached from the mapping and buffers cannot
+			 * get reused.
 			 */
 			mapping = READ_ONCE(bh->b_page->mapping);
 			if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {