Lines Matching full:mark
7 * fsnotify inode mark locking/lifetime/and refcnting
10 * The group->recnt and mark->refcnt tell how many "things" in the kernel
13 * the reference a group and a mark hold to each other.
22 * mark->lock
23 * mark->connector->lock
26 * each mark is hooked via the g_list. It also protects the groups private
29 * mark->lock protects the marks attributes like its masks and flags.
30 * Furthermore it protects the access to a reference of the group that the mark
32 * that is being watched by the mark.
34 * mark->connector->lock protects the list of marks anchored inside an
35 * inode / vfsmount and each mark is hooked via the i_list.
39 * marks in the list and is also protected by fsnotify_mark_srcu. A mark gets
40 * detached from fsnotify_mark_connector when last reference to the mark is
41 * dropped. Thus having mark reference is enough to protect mark->connector
43 * because we remove mark from g_list before dropping mark reference associated
44 * with that, any mark found through g_list is guaranteed to have
45 * mark->connector set until we drop group->mark_mutex.
51 * The inode mark can be cleared for a number of different reasons including:
56 * - The fsnotify_group associated with the mark is going away and all such marks
94 void fsnotify_get_mark(struct fsnotify_mark *mark) in fsnotify_get_mark() argument
96 WARN_ON_ONCE(!refcount_read(&mark->refcnt)); in fsnotify_get_mark()
97 refcount_inc(&mark->refcnt); in fsnotify_get_mark()
122 struct fsnotify_mark *mark; in __fsnotify_recalc_mask() local
128 hlist_for_each_entry(mark, &conn->list, obj_list) { in __fsnotify_recalc_mask()
129 if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED) in __fsnotify_recalc_mask()
130 new_mask |= mark->mask; in __fsnotify_recalc_mask()
138 * this by holding a mark->lock or mark->group->mark_mutex for a mark on this
199 static void fsnotify_final_mark_destroy(struct fsnotify_mark *mark) in fsnotify_final_mark_destroy() argument
201 struct fsnotify_group *group = mark->group; in fsnotify_final_mark_destroy()
205 group->ops->free_mark(mark); in fsnotify_final_mark_destroy()
227 void fsnotify_put_mark(struct fsnotify_mark *mark) in fsnotify_put_mark() argument
229 struct fsnotify_mark_connector *conn = READ_ONCE(mark->connector); in fsnotify_put_mark()
236 if (refcount_dec_and_test(&mark->refcnt)) in fsnotify_put_mark()
237 fsnotify_final_mark_destroy(mark); in fsnotify_put_mark()
243 * safely grab mark reference. in fsnotify_put_mark()
245 if (!refcount_dec_and_lock(&mark->refcnt, &conn->lock)) in fsnotify_put_mark()
248 hlist_del_init_rcu(&mark->obj_list); in fsnotify_put_mark()
255 WRITE_ONCE(mark->connector, NULL); in fsnotify_put_mark()
274 list_add(&mark->g_list, &destroy_list); in fsnotify_put_mark()
282 * Get mark reference when we found the mark via lockless traversal of object
283 * list. Mark can be already removed from the list by now and on its way to be
288 static bool fsnotify_get_mark_safe(struct fsnotify_mark *mark) in fsnotify_get_mark_safe() argument
290 if (!mark) in fsnotify_get_mark_safe()
293 if (refcount_inc_not_zero(&mark->refcnt)) { in fsnotify_get_mark_safe()
294 spin_lock(&mark->lock); in fsnotify_get_mark_safe()
295 if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED) { in fsnotify_get_mark_safe()
296 /* mark is attached, group is still alive then */ in fsnotify_get_mark_safe()
297 atomic_inc(&mark->group->user_waits); in fsnotify_get_mark_safe()
298 spin_unlock(&mark->lock); in fsnotify_get_mark_safe()
301 spin_unlock(&mark->lock); in fsnotify_get_mark_safe()
302 fsnotify_put_mark(mark); in fsnotify_get_mark_safe()
312 static void fsnotify_put_mark_wake(struct fsnotify_mark *mark) in fsnotify_put_mark_wake() argument
314 if (mark) { in fsnotify_put_mark_wake()
315 struct fsnotify_group *group = mark->group; in fsnotify_put_mark_wake()
317 fsnotify_put_mark(mark); in fsnotify_put_mark_wake()
333 /* This can fail if mark is being removed */ in fsnotify_prepare_user_wait()
366 * Mark mark as detached, remove it from group list. Mark still stays in object
367 * list until its last reference is dropped. Note that we rely on mark being
369 * particular we rely on mark->connector being valid while we hold
370 * group->mark_mutex if we found the mark through g_list.
373 * reference to the mark or be protected by fsnotify_mark_srcu.
375 void fsnotify_detach_mark(struct fsnotify_mark *mark) in fsnotify_detach_mark() argument
377 struct fsnotify_group *group = mark->group; in fsnotify_detach_mark()
381 refcount_read(&mark->refcnt) < 1 + in fsnotify_detach_mark()
382 !!(mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)); in fsnotify_detach_mark()
384 spin_lock(&mark->lock); in fsnotify_detach_mark()
385 /* something else already called this function on this mark */ in fsnotify_detach_mark()
386 if (!(mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { in fsnotify_detach_mark()
387 spin_unlock(&mark->lock); in fsnotify_detach_mark()
390 mark->flags &= ~FSNOTIFY_MARK_FLAG_ATTACHED; in fsnotify_detach_mark()
391 list_del_init(&mark->g_list); in fsnotify_detach_mark()
392 spin_unlock(&mark->lock); in fsnotify_detach_mark()
396 /* Drop mark reference acquired in fsnotify_add_mark_locked() */ in fsnotify_detach_mark()
397 fsnotify_put_mark(mark); in fsnotify_detach_mark()
401 * Free fsnotify mark. The mark is actually only marked as being freed. The
402 * freeing is actually happening only once last reference to the mark is
405 * Caller must have a reference to the mark or be protected by
408 void fsnotify_free_mark(struct fsnotify_mark *mark) in fsnotify_free_mark() argument
410 struct fsnotify_group *group = mark->group; in fsnotify_free_mark()
412 spin_lock(&mark->lock); in fsnotify_free_mark()
413 /* something else already called this function on this mark */ in fsnotify_free_mark()
414 if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) { in fsnotify_free_mark()
415 spin_unlock(&mark->lock); in fsnotify_free_mark()
418 mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; in fsnotify_free_mark()
419 spin_unlock(&mark->lock); in fsnotify_free_mark()
423 * callback to the group function to let it know that this mark in fsnotify_free_mark()
427 group->ops->freeing_mark(mark, group); in fsnotify_free_mark()
430 void fsnotify_destroy_mark(struct fsnotify_mark *mark, in fsnotify_destroy_mark() argument
434 fsnotify_detach_mark(mark); in fsnotify_destroy_mark()
436 fsnotify_free_mark(mark); in fsnotify_destroy_mark()
515 * Get mark connector, make sure it is alive and return with its lock held.
517 * hold reference to a mark on the list may directly lock connector->lock as
542 * Add mark into proper place in given list of marks. These marks may be used
547 static int fsnotify_add_mark_list(struct fsnotify_mark *mark, in fsnotify_add_mark_list() argument
564 spin_lock(&mark->lock); in fsnotify_add_mark_list()
567 spin_unlock(&mark->lock); in fsnotify_add_mark_list()
595 /* is mark the first mark? */ in fsnotify_add_mark_list()
597 hlist_add_head_rcu(&mark->obj_list, &conn->list); in fsnotify_add_mark_list()
601 /* should mark be in the middle of the current list? */ in fsnotify_add_mark_list()
605 if ((lmark->group == mark->group) && in fsnotify_add_mark_list()
612 cmp = fsnotify_compare_groups(lmark->group, mark->group); in fsnotify_add_mark_list()
614 hlist_add_before_rcu(&mark->obj_list, &lmark->obj_list); in fsnotify_add_mark_list()
620 /* mark should be the last entry. last is the current last entry */ in fsnotify_add_mark_list()
621 hlist_add_behind_rcu(&mark->obj_list, &last->obj_list); in fsnotify_add_mark_list()
626 * seeing mark->connector set. in fsnotify_add_mark_list()
628 WRITE_ONCE(mark->connector, conn); in fsnotify_add_mark_list()
631 spin_unlock(&mark->lock); in fsnotify_add_mark_list()
636 * Attach an initialized mark to a given group and fs object.
640 int fsnotify_add_mark_locked(struct fsnotify_mark *mark, in fsnotify_add_mark_locked() argument
644 struct fsnotify_group *group = mark->group; in fsnotify_add_mark_locked()
652 * mark->lock in fsnotify_add_mark_locked()
653 * mark->connector->lock in fsnotify_add_mark_locked()
655 spin_lock(&mark->lock); in fsnotify_add_mark_locked()
656 mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_ATTACHED; in fsnotify_add_mark_locked()
658 list_add(&mark->g_list, &group->marks_list); in fsnotify_add_mark_locked()
660 fsnotify_get_mark(mark); /* for g_list */ in fsnotify_add_mark_locked()
661 spin_unlock(&mark->lock); in fsnotify_add_mark_locked()
663 ret = fsnotify_add_mark_list(mark, connp, type, allow_dups, fsid); in fsnotify_add_mark_locked()
667 if (mark->mask) in fsnotify_add_mark_locked()
668 fsnotify_recalc_mask(mark->connector); in fsnotify_add_mark_locked()
672 spin_lock(&mark->lock); in fsnotify_add_mark_locked()
673 mark->flags &= ~(FSNOTIFY_MARK_FLAG_ALIVE | in fsnotify_add_mark_locked()
675 list_del_init(&mark->g_list); in fsnotify_add_mark_locked()
676 spin_unlock(&mark->lock); in fsnotify_add_mark_locked()
679 fsnotify_put_mark(mark); in fsnotify_add_mark_locked()
683 int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_connp_t *connp, in fsnotify_add_mark() argument
687 struct fsnotify_group *group = mark->group; in fsnotify_add_mark()
690 ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups, fsid); in fsnotify_add_mark()
697 * Given a list of marks, find the mark associated with given group. If found
698 * take a reference to that mark and return it, else return NULL.
704 struct fsnotify_mark *mark; in fsnotify_find_mark() local
710 hlist_for_each_entry(mark, &conn->list, obj_list) { in fsnotify_find_mark()
711 if (mark->group == group && in fsnotify_find_mark()
712 (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { in fsnotify_find_mark()
713 fsnotify_get_mark(mark); in fsnotify_find_mark()
715 return mark; in fsnotify_find_mark()
727 struct fsnotify_mark *lmark, *mark; in fsnotify_clear_marks_by_group() local
740 * list. And freeing mark requires us to drop mark_mutex. So we can in fsnotify_clear_marks_by_group()
741 * reliably free only the first mark in the list. That's why we first in fsnotify_clear_marks_by_group()
746 list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) { in fsnotify_clear_marks_by_group()
747 if ((1U << mark->connector->type) & type_mask) in fsnotify_clear_marks_by_group()
748 list_move(&mark->g_list, &to_free); in fsnotify_clear_marks_by_group()
759 mark = list_first_entry(head, struct fsnotify_mark, g_list); in fsnotify_clear_marks_by_group()
760 fsnotify_get_mark(mark); in fsnotify_clear_marks_by_group()
761 fsnotify_detach_mark(mark); in fsnotify_clear_marks_by_group()
763 fsnotify_free_mark(mark); in fsnotify_clear_marks_by_group()
764 fsnotify_put_mark(mark); in fsnotify_clear_marks_by_group()
772 struct fsnotify_mark *mark, *old_mark = NULL; in fsnotify_destroy_marks() local
782 * list can get modified. However we are holding mark reference and in fsnotify_destroy_marks()
783 * thus our mark cannot be removed from obj_list so we can continue in fsnotify_destroy_marks()
786 hlist_for_each_entry(mark, &conn->list, obj_list) { in fsnotify_destroy_marks()
787 fsnotify_get_mark(mark); in fsnotify_destroy_marks()
791 old_mark = mark; in fsnotify_destroy_marks()
792 fsnotify_destroy_mark(mark, mark->group); in fsnotify_destroy_marks()
797 * mark references get dropped. It would lead to strange results such in fsnotify_destroy_marks()
810 void fsnotify_init_mark(struct fsnotify_mark *mark, in fsnotify_init_mark() argument
813 memset(mark, 0, sizeof(*mark)); in fsnotify_init_mark()
814 spin_lock_init(&mark->lock); in fsnotify_init_mark()
815 refcount_set(&mark->refcnt, 1); in fsnotify_init_mark()
817 mark->group = group; in fsnotify_init_mark()
818 WRITE_ONCE(mark->connector, NULL); in fsnotify_init_mark()
828 struct fsnotify_mark *mark, *next; in fsnotify_mark_destroy_workfn() local
838 list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) { in fsnotify_mark_destroy_workfn()
839 list_del_init(&mark->g_list); in fsnotify_mark_destroy_workfn()
840 fsnotify_final_mark_destroy(mark); in fsnotify_mark_destroy_workfn()