Commit 62cb0af4 authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

dnotify: report both events on parent and child with single callback 

For some events (e.g. DN_ATTRIB on sub-directory) fsnotify may call
dnotify_handle_event() once for watching parent and once again for
the watching sub-directory.

Do the same thing with a single callback instead of two callbacks when
marks iterator contains both inode and child entries.

Link: https://lore.kernel.org/r/20200716084230.30611-12-amir73il@gmail.com


Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent f35c4156

fs/notify/dnotify/dnotify.c

+29 −13
Original line number Diff line number Diff line
@@ -70,26 +70,15 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark *fsn_mark) 
 * destroy the dnotify struct if it was not registered to receive multiple

 * events.

 */

static int dnotify_handle_event(struct fsnotify_group *group, u32 mask,

				const void *data, int data_type,

				struct inode *dir,

				const struct qstr *file_name, u32 cookie,

				struct fsnotify_iter_info *iter_info)

static void dnotify_one_event(struct fsnotify_group *group, u32 mask,

			      struct fsnotify_mark *inode_mark)

{

	struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);

	struct dnotify_mark *dn_mark;

	struct dnotify_struct *dn;

	struct dnotify_struct **prev;

	struct fown_struct *fown;

	__u32 test_mask = mask & ~FS_EVENT_ON_CHILD;



	/* not a dir, dnotify doesn't care */

	if (!dir && !(mask & FS_ISDIR))

		return 0;



	if (WARN_ON(fsnotify_iter_vfsmount_mark(iter_info)))

		return 0;



	dn_mark = container_of(inode_mark, struct dnotify_mark, fsn_mark);



	spin_lock(&inode_mark->lock);
@@ -111,6 +100,33 @@ static int dnotify_handle_event(struct fsnotify_group *group, u32 mask, 
	}



	spin_unlock(&inode_mark->lock);

}



static int dnotify_handle_event(struct fsnotify_group *group, u32 mask,

				const void *data, int data_type,

				struct inode *dir,

				const struct qstr *file_name, u32 cookie,

				struct fsnotify_iter_info *iter_info)

{

	struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);

	struct fsnotify_mark *child_mark = fsnotify_iter_child_mark(iter_info);



	/* not a dir, dnotify doesn't care */

	if (!dir && !(mask & FS_ISDIR))

		return 0;



	if (WARN_ON(fsnotify_iter_vfsmount_mark(iter_info)))

		return 0;



	/*

	 * Some events can be sent on both parent dir and subdir marks

	 * (e.g. DN_ATTRIB).  If both parent dir and subdir are watching,

	 * report the event once to parent dir and once to subdir.

	 */

	if (inode_mark)

		dnotify_one_event(group, mask, inode_mark);

	if (child_mark)

		dnotify_one_event(group, mask, child_mark);



	return 0;

}

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