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

Pull ext4 updates from Ted Ts'o:
 "All cleanups and bug fixes; most notably, fix some problems discovered
  in ext4's NFS support, and fix an ioctl (EXT4_IOC_GROUP_ADD) used by
  old versions of e2fsprogs which we accidentally broke a while back.

  Also fixed some error paths in ext4's quota and inline data support.

  Finally, improve tail latency in jbd2's commit code"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: check for shutdown and r/o file system in ext4_write_inode()
  ext4: force inode writes when nfsd calls commit_metadata()
  ext4: avoid declaring fs inconsistent due to invalid file handles
  ext4: include terminating u32 in size of xattr entries when expanding inodes
  ext4: compare old and new mode before setting update_mode flag
  ext4: fix EXT4_IOC_GROUP_ADD ioctl
  ext4: hard fail dax mount on unsupported devices
  jbd2: update locking documentation for transaction_t
  ext4: remove redundant condition check
  jbd2: clean up indentation issue, replace spaces with tab
  ext4: clean up indentation issues, remove extraneous tabs
  ext4: missing unlock/put_page() in ext4_try_to_write_inline_data()
  ext4: fix possible use after free in ext4_quota_enable
  jbd2: avoid long hold times of j_state_lock while committing a transaction
  ext4: add ext4_sb_bread() to disambiguate ENOMEM cases

include/linux/jbd2.h

@@ -575,6 +575,7 @@ struct transaction_s
 	enum {
 		T_RUNNING,
 		T_LOCKED,
+		T_SWITCH,
 		T_FLUSH,
 		T_COMMIT,
 		T_COMMIT_DFLUSH,
@@ -662,13 +663,13 @@ struct transaction_s
 
 	/*
 	 * Number of outstanding updates running on this transaction
-	 * [t_handle_lock]
+	 * [none]
 	 */
 	atomic_t		t_updates;
 
 	/*
 	 * Number of buffers reserved for use by all handles in this transaction
-	 * handle but not yet modified. [t_handle_lock]
+	 * handle but not yet modified. [none]
 	 */
 	atomic_t		t_outstanding_credits;
 
@@ -690,7 +691,7 @@ struct transaction_s
 	ktime_t			t_start_time;
 
 	/*
-	 * How many handles used this transaction? [t_handle_lock]
+	 * How many handles used this transaction? [none]
 	 */
 	atomic_t		t_handle_count;