Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (36 commits)
  ext4: fix up rb_root initializations to use RB_ROOT
  ext4: Code cleanup for EXT4_IOC_MOVE_EXT ioctl
  ext4: Fix the NULL reference in double_down_write_data_sem()
  ext4: Fix insertion point of extent in mext_insert_across_blocks()
  ext4: consolidate in_range() definitions
  ext4: cleanup to use ext4_grp_offs_to_block()
  ext4: cleanup to use ext4_group_first_block_no()
  ext4: Release page references acquired in ext4_da_block_invalidatepages
  ext4: Fix ext4_quota_write cross block boundary behaviour
  ext4: Convert BUG_ON checks to use ext4_error() instead
  ext4: Use direct_IO_no_locking in ext4 dio read
  ext4: use ext4_get_block_write in buffer write
  ext4: mechanical rename some of the direct I/O get_block's identifiers
  ext4: make "offset" consistent in ext4_check_dir_entry()
  ext4: Handle non empty on-disk orphan link
  ext4: explicitly remove inode from orphan list after failed direct io
  ext4: fix error handling in migrate
  ext4: deprecate obsoleted mount options
  ext4: Fix fencepost error in chosing choosing group vs file preallocation.
  jbd2: clean up an assertion in jbd2_journal_commit_transaction()
  ...

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 05eca817d70..b79ad512646 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -304,4 +304,28 @@ static inline int ext4_should_writeback_data(struct inode *inode)
 	return 0;
 }
 
+/*
+ * This function controls whether or not we should try to go down the
+ * dioread_nolock code paths, which makes it safe to avoid taking
+ * i_mutex for direct I/O reads.  This only works for extent-based
+ * files, and it doesn't work for nobh or if data journaling is
+ * enabled, since the dioread_nolock code uses b_private to pass
+ * information back to the I/O completion handler, and this conflicts
+ * with the jbd's use of b_private.
+ */
+static inline int ext4_should_dioread_nolock(struct inode *inode)
+{
+	if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
+		return 0;
+	if (test_opt(inode->i_sb, NOBH))
+		return 0;
+	if (!S_ISREG(inode->i_mode))
+		return 0;
+	if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+		return 0;
+	if (ext4_should_journal_data(inode))
+		return 0;
+	return 1;
+}
+
 #endif	/* _EXT4_JBD2_H */