From e220140ff6241e180d0c2fc294e61ee6bbc6a18e Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 10 Jan 2019 19:04:29 +0200 Subject: [PATCH] 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: Amir Goldstein Signed-off-by: Jan Kara --- include/linux/fsnotify_backend.h | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 7639774..7f195d4 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -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 | \ -- 2.7.4