Commit e220140f authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

fsnotify: remove dirent events from FS_EVENTS_POSS_ON_CHILD mask 



"dirent" events are referring to events that modify directory entries,
such as create,delete,rename. Those events are always be reported
on a watched directory, regardless if FS_EVENT_ON_CHILD is set
on the watch mask.

ALL_FSNOTIFY_DIRENT_EVENTS defines all the dirent event types and
those event types are removed from FS_EVENTS_POSS_ON_CHILD.

That means for a directory with an inotify watch and only dirent
events in the mask (i.e. create,delete,move), all children dentries
will no longer have the DCACHE_FSNOTIFY_PARENT_WATCHED flag set.
This will allow all events that happen on children to be optimized
away in __fsnotify_parent() without the need to dereference
child->d_parent->d_inode->i_fsnotify_mask.

Since the dirent events are never repoted via __fsnotify_parent(),
this results in no change of logic, but only an optimization.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 5f02a877

include/linux/fsnotify_backend.h

+21 −15
Original line number Diff line number Diff line
@@ -59,27 +59,33 @@ 
 * dnotify and inotify. */

#define FS_EVENT_ON_CHILD	0x08000000



/* This is a list of all events that may get sent to a parernt based on fs event

 * happening to inodes inside that directory */

#define FS_EVENTS_POSS_ON_CHILD   (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\

				   FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\

				   FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\

				   FS_DELETE | FS_OPEN_PERM | FS_ACCESS_PERM | \

				   FS_OPEN_EXEC | FS_OPEN_EXEC_PERM)



#define FS_MOVE			(FS_MOVED_FROM | FS_MOVED_TO)



/*

 * Directory entry modification events - reported only to directory

 * where entry is modified and not to a watching parent.

 * The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event

 * when a directory entry inside a child subdir changes.

 */

#define ALL_FSNOTIFY_DIRENT_EVENTS	(FS_CREATE | FS_DELETE | FS_MOVE)



#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \

				  FS_OPEN_EXEC_PERM)



/*

 * This is a list of all events that may get sent to a parent based on fs event

 * happening to inodes inside that directory.

 */

#define FS_EVENTS_POSS_ON_CHILD   (ALL_FSNOTIFY_PERM_EVENTS | \

				   FS_ACCESS | FS_MODIFY | FS_ATTRIB | \

				   FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \

				   FS_OPEN | FS_OPEN_EXEC)



/* Events that can be reported to backends */

#define ALL_FSNOTIFY_EVENTS (FS_ACCESS | FS_MODIFY | FS_ATTRIB | \

			     FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN | \

			     FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE | \

			     FS_DELETE | FS_DELETE_SELF | FS_MOVE_SELF | \

			     FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \

			     FS_OPEN_PERM | FS_ACCESS_PERM | FS_DN_RENAME | \

			     FS_OPEN_EXEC | FS_OPEN_EXEC_PERM)

#define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \

			     FS_EVENTS_POSS_ON_CHILD | \

			     FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \

			     FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED)



/* Extra flags that may be reported with event or control handling of events */

#define ALL_FSNOTIFY_FLAGS  (FS_EXCL_UNLINK | FS_ISDIR | FS_IN_ONESHOT | \

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