48  * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
49  * log, we must force a full commit before doing an fsync of the directory
57  * fsync foo/some_dir/some_file
59  * The fsync above will unlink the original some_dir without recording
61  * unless the fsync of some_file forces a full commit
63  * 2) we must log any new names for any file or dir that is in the fsync
79  * fsync(f1)
81  * The directory f1 was fully removed from the FS, but fsync was never
126  * Instead of doing a tree commit on every fsync, we use the
130  * and then the fsync is considered complete.
555 			 * fsync, and the inode wasn't fsynced before. In this  in overwrite_item()
1764  * for inodes that actually exist.  This means an fsync on a directory
1765  * does not implicitly fsync all the new files in it
2002 	 * xfs_io -c "fsync" testdir/bar  in replay_one_dir_item()
2037  * that means it was deleted from the directory before the fsync
2444 			 * If we have a tmpfile (O_TMPFILE) that got fsync'ed  in replay_one_buffer()
2445 			 * and never got linked before the fsync, skip it, as  in replay_one_buffer()
2476 			 * because before an fsync we can have prealloc extents  in replay_one_buffer()
2921  * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
3463  * fsync file X
3465  * fsync dir Y
3468  * didn't get fsync'd again so the log has back refs for X and X.link.
3472  * unlinked.  Any later fsync will include the updated log entries, and
3785 		 * xfs_io -c "fsync" mydir  in process_dir_items_leaf()
3789 		 * Would result in a fsync log that when replayed, our file inode  in process_dir_items_leaf()
3826  * to replay anything deleted before the fsync
4235 	 * We do not need to set the nbytes field, in fact during a fast fsync  in fill_inode_item()
4236 	 * its value may not even be correct, since a fast fsync does not wait  in fill_inode_item()
4262 	 * If we are doing a fast fsync and the inode was logged before in the  in log_inode_item()
4278 		 * This means it is the first fsync in the current transaction,  in log_inode_item()
4281 		 * fsync and in case an inode eviction happens after the inode was  in log_inode_item()
4438 		 * few random writes into a file and then fsync it for the first  in copy_items()
4788  * lose them after doing a full/fast fsync and replaying the log. We scan the
4889 		 * get here, get rid of everything from a past fsync. After  in btrfs_log_prealloc_extents()
5256  * xfs_io -c fsync /mnt/x
5268  * xfs_io -c fsync /mnt/foo
5281  * fsync /mnt/x or fsync some new file inside it
5284  * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
6474 	 *     $ xfs_io -c "fsync" a  in btrfs_log_inode()
6530 	 * directory A to a directory B, then fsync directory A, we have no way  in btrfs_log_inode()
6556 			 * 0, fsync, write 4K into offset 4096, add hard link,  in btrfs_log_inode()
6557 			 * fsync some other file (to sync log), power fail - if  in btrfs_log_inode()
6641 		 * If we are doing a fast fsync and the inode was logged before  in btrfs_log_inode()
6693 	 *    happened. We must make sure that if an explicit fsync against  in btrfs_log_inode()
6701 	 *    truncate operation, the log is synced through an fsync of  in btrfs_log_inode()
6702 	 *    some other inode and then finally an explicit fsync against  in btrfs_log_inode()
6703 	 *    this inode is made, we must make sure this fsync logs the  in btrfs_log_inode()
6709 	 *    its last_log_commit - otherwise if an explicit fsync is made  in btrfs_log_inode()
6710 	 *    against an ancestor, the fsync considers the inode in the log  in btrfs_log_inode()
6712 	 *    a power failure unless the log was synced as part of an fsync  in btrfs_log_inode()
6720 	 * Reset the last_reflink_trans so that the next fsync does not need to  in btrfs_log_inode()
6823 			 * it got fsync'ed, from existing at both parents after  in btrfs_log_all_parents()
6833 			 * fsync /mnt/B/bar  in btrfs_log_all_parents()
7141 	 * xfs_io -c fsync testdir/foo  in btrfs_log_inode_parent()
7158 	 * xfs_io -c fsync foo  in btrfs_log_inode_parent()
7394  * properly done if it is fsync'd later after the unlinks are done.
7440 	 * there we're unlinking from gets fsync'd later on, there's  in btrfs_record_unlink_dir()
7441 	 * no way to find the destination directory later and fsync it  in btrfs_record_unlink_dir()
7451  * Make sure that if someone attempts to fsync the parent directory of a deleted