Commit f09b04a0 authored by Jan Kara's avatar Jan Kara
Browse files

fsnotify: Remove special handling of mark destruction on group shutdown 



Currently we queue all marks for destruction on group shutdown and then
destroy them from fsnotify_destroy_group() instead from a worker thread
which is the usual path. However worker can already be processing some
list of marks to destroy so this does not make 100% all marks are really
destroyed by the time group is shut down. This isn't a big problem as
each mark holds group reference and thus group stays partially alive
until all marks are really freed but there's no point in complicating
our lives - just wait for the delayed work to be finished instead.

Reviewed-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 6b3f05d2

fs/notify/fsnotify.h

+2 −4
Original line number Diff line number Diff line
@@ -36,10 +36,8 @@ static inline void fsnotify_clear_marks_by_mount(struct vfsmount *mnt) 
}

/* prepare for freeing all marks associated with given group */

extern void fsnotify_detach_group_marks(struct fsnotify_group *group);

/*

 * wait for fsnotify_mark_srcu period to end and free all marks in destroy_list

 */

extern void fsnotify_mark_destroy_list(void);

/* Wait until all marks queued for destruction are destroyed */

extern void fsnotify_wait_marks_destroyed(void);



/*

 * update the dentry->d_flags of all of inode's children to indicate if inode cares

fs/notify/group.c

+6 −4
Original line number Diff line number Diff line
@@ -66,14 +66,16 @@ void fsnotify_destroy_group(struct fsnotify_group *group) 
	 */

	fsnotify_group_stop_queueing(group);



	/* clear all inode marks for this group, attach them to destroy_list */

	/* Clear all marks for this group and queue them for destruction */

	fsnotify_detach_group_marks(group);



	/*

	 * Wait for fsnotify_mark_srcu period to end and free all marks in

	 * destroy_list

	 * Wait until all marks get really destroyed. We could actually destroy

	 * them ourselves instead of waiting for worker to do it, however that

	 * would be racy as worker can already be processing some marks before

	 * we even entered fsnotify_destroy_group().

	 */

	fsnotify_mark_destroy_list();

	fsnotify_wait_marks_destroyed();



	/*

	 * Since we have waited for fsnotify_mark_srcu in

fs/notify/mark.c

+4 −3
Original line number Diff line number Diff line
@@ -703,7 +703,7 @@ void fsnotify_init_mark(struct fsnotify_mark *mark, 
 * Destroy all marks in destroy_list, waits for SRCU period to finish before

 * actually freeing marks.

 */

void fsnotify_mark_destroy_list(void)

static void fsnotify_mark_destroy_workfn(struct work_struct *work)

{

	struct fsnotify_mark *mark, *next;

	struct list_head private_destroy_list;
@@ -721,7 +721,8 @@ void fsnotify_mark_destroy_list(void) 
	}

}



static void fsnotify_mark_destroy_workfn(struct work_struct *work)

/* Wait for all marks queued for destruction to be actually destroyed */

void fsnotify_wait_marks_destroyed(void)

{

	fsnotify_mark_destroy_list();

	flush_delayed_work(&reaper_work);

}

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