Merge tag 'ext4_for_linus_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes and cleanups from Ted Ts'o:
 "More fixes and cleanups for the new fast_commit features, but also a
  few other miscellaneous bug fixes and a cleanup for the MAINTAINERS
  file"

* tag 'ext4_for_linus_cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (28 commits)
  jbd2: fix up sparse warnings in checkpoint code
  ext4: fix sparse warnings in fast_commit code
  ext4: cleanup fast commit mount options
  jbd2: don't start fast commit on aborted journal
  ext4: make s_mount_flags modifications atomic
  ext4: issue fsdev cache flush before starting fast commit
  ext4: disable fast commit with data journalling
  ext4: fix inode dirty check in case of fast commits
  ext4: remove unnecessary fast commit calls from ext4_file_mmap
  ext4: mark buf dirty before submitting fast commit buffer
  ext4: fix code documentatioon
  ext4: dedpulicate the code to wait on inode that's being committed
  jbd2: don't read journal->j_commit_sequence without taking a lock
  jbd2: don't touch buffer state until it is filled
  jbd2: add todo for a fast commit performance optimization
  jbd2: don't pass tid to jbd2_fc_end_commit_fallback()
  jbd2: don't use state lock during commit path
  jbd2: drop jbd2_fc_init documentation
  ext4: clean up the JBD2 API that initializes fast commits
  jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufs
  ...

3 files changed, 15 insertions, 4 deletions

diff --git a/Documentation/filesystems/ext4/journal.rst b/Documentation/filesystems/ext4/journal.rst
index 805a1e9ea3a5..849d5b119eb8 100644
--- a/Documentation/filesystems/ext4/journal.rst
+++ b/Documentation/filesystems/ext4/journal.rst
@@ -256,6 +256,10 @@ which is 1024 bytes long:
      - s\_padding2
      -
    * - 0x54
+     - \_\_be32
+     - s\_num\_fc\_blocks
+     - Number of fast commit blocks in the journal.
+   * - 0x58
      - \_\_u32
      - s\_padding[42]
      -
@@ -310,6 +314,8 @@ The journal incompat features are any combination of the following:
      - This journal uses v3 of the checksum on-disk format. This is the same as
        v2, but the journal block tag size is fixed regardless of the size of
        block numbers. (JBD2\_FEATURE\_INCOMPAT\_CSUM\_V3)
+   * - 0x20
+     - Journal has fast commit blocks. (JBD2\_FEATURE\_INCOMPAT\_FAST\_COMMIT)
 
 .. _jbd2_checksum_type:
 
diff --git a/Documentation/filesystems/ext4/super.rst b/Documentation/filesystems/ext4/super.rst
index 93e55d7c1d40..2eb1ab20498d 100644
--- a/Documentation/filesystems/ext4/super.rst
+++ b/Documentation/filesystems/ext4/super.rst
@@ -596,6 +596,13 @@ following:
      - Sparse Super Block, v2. If this flag is set, the SB field s\_backup\_bgs
        points to the two block groups that contain backup superblocks
        (COMPAT\_SPARSE\_SUPER2).
+   * - 0x400
+     - Fast commits supported. Although fast commits blocks are
+       backward incompatible, fast commit blocks are not always
+       present in the journal. If fast commit blocks are present in
+       the journal, JBD2 incompat feature
+       (JBD2\_FEATURE\_INCOMPAT\_FAST\_COMMIT) gets
+       set (COMPAT\_FAST\_COMMIT).
 
 .. _super_incompat:
 
diff --git a/Documentation/filesystems/journalling.rst b/Documentation/filesystems/journalling.rst
index 5a5f70b4063e..e18f90ffc6fd 100644
--- a/Documentation/filesystems/journalling.rst
+++ b/Documentation/filesystems/journalling.rst
@@ -136,10 +136,8 @@ Fast commits
 ~~~~~~~~~~~~
 
 JBD2 to also allows you to perform file-system specific delta commits known as
-fast commits. In order to use fast commits, you first need to call
-:c:func:`jbd2_fc_init` and tell how many blocks at the end of journal
-area should be reserved for fast commits. Along with that, you will also need
-to set following callbacks that perform correspodning work:
+fast commits. In order to use fast commits, you will need to set following
+callbacks that perform correspodning work:
 
 `journal->j_fc_cleanup_cb`: Cleanup function called after every full commit and
 fast commit.