diff options
Diffstat (limited to 'fs/notify/mark.c')
| -rw-r--r-- | fs/notify/mark.c | 133 |
1 files changed, 126 insertions, 7 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index d90deaa08e78..92e48c70f0f0 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -110,6 +110,17 @@ void fsnotify_put_mark(struct fsnotify_mark *mark) } } +/* Calculate mask of events for a list of marks */ +u32 fsnotify_recalc_mask(struct hlist_head *head) +{ + u32 new_mask = 0; + struct fsnotify_mark *mark; + + hlist_for_each_entry(mark, head, obj_list) + new_mask |= mark->mask; + return new_mask; +} + /* * Any time a mark is getting freed we end up here. * The caller had better be holding a reference to this mark so we don't actually @@ -133,7 +144,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) { - inode = mark->i.inode; + inode = mark->inode; fsnotify_destroy_inode_mark(mark); } else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) fsnotify_destroy_vfsmount_mark(mark); @@ -150,7 +161,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); - list_add(&mark->destroy_list, &destroy_list); + list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); /* @@ -192,6 +203,27 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, mutex_unlock(&group->mark_mutex); } +/* + * Destroy all marks in the given list. The marks must be already detached from + * the original inode / vfsmount. + */ +void fsnotify_destroy_marks(struct list_head *to_free) +{ + struct fsnotify_mark *mark, *lmark; + struct fsnotify_group *group; + + list_for_each_entry_safe(mark, lmark, to_free, free_list) { + spin_lock(&mark->lock); + fsnotify_get_group(mark->group); + group = mark->group; + spin_unlock(&mark->lock); + + fsnotify_destroy_mark(mark, group); + fsnotify_put_mark(mark); + fsnotify_put_group(group); + } +} + void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask) { assert_spin_locked(&mark->lock); @@ -210,6 +242,75 @@ void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mas } /* + * Sorting function for lists of fsnotify marks. + * + * Fanotify supports different notification classes (reflected as priority of + * notification group). Events shall be passed to notification groups in + * decreasing priority order. To achieve this marks in notification lists for + * inodes and vfsmounts are sorted so that priorities of corresponding groups + * are descending. + * + * Furthermore correct handling of the ignore mask requires processing inode + * and vfsmount marks of each group together. Using the group address as + * further sort criterion provides a unique sorting order and thus we can + * merge inode and vfsmount lists of marks in linear time and find groups + * present in both lists. + * + * A return value of 1 signifies that b has priority over a. + * A return value of 0 signifies that the two marks have to be handled together. + * A return value of -1 signifies that a has priority over b. + */ +int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b) +{ + if (a == b) + return 0; + if (!a) + return 1; + if (!b) + return -1; + if (a->priority < b->priority) + return 1; + if (a->priority > b->priority) + return -1; + if (a < b) + return 1; + return -1; +} + +/* Add mark into proper place in given list of marks */ +int fsnotify_add_mark_list(struct hlist_head *head, struct fsnotify_mark *mark, + int allow_dups) +{ + struct fsnotify_mark *lmark, *last = NULL; + int cmp; + + /* is mark the first mark? */ + if (hlist_empty(head)) { + hlist_add_head_rcu(&mark->obj_list, head); + return 0; + } + + /* should mark be in the middle of the current list? */ + hlist_for_each_entry(lmark, head, obj_list) { + last = lmark; + + if ((lmark->group == mark->group) && !allow_dups) + return -EEXIST; + + cmp = fsnotify_compare_groups(lmark->group, mark->group); + if (cmp >= 0) { + hlist_add_before_rcu(&mark->obj_list, &lmark->obj_list); + return 0; + } + } + + BUG_ON(last == NULL); + /* mark should be the last entry. last is the current last entry */ + hlist_add_behind_rcu(&mark->obj_list, &last->obj_list); + return 0; +} + +/* * Attach an initialized mark to a given group and fs object. * These marks may be used for the fsnotify backend to determine which * event types should be delivered to which group. @@ -269,7 +370,7 @@ err: spin_unlock(&mark->lock); spin_lock(&destroy_lock); - list_add(&mark->destroy_list, &destroy_list); + list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); @@ -287,6 +388,24 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group, } /* + * Given a list of marks, find the mark associated with given group. If found + * take a reference to that mark and return it, else return NULL. + */ +struct fsnotify_mark *fsnotify_find_mark(struct hlist_head *head, + struct fsnotify_group *group) +{ + struct fsnotify_mark *mark; + + hlist_for_each_entry(mark, head, obj_list) { + if (mark->group == group) { + fsnotify_get_mark(mark); + return mark; + } + } + return NULL; +} + +/* * clear any marks in a group in which mark->flags & flags is true */ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, @@ -316,8 +435,8 @@ void fsnotify_clear_marks_by_group(struct fsnotify_group *group) void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old) { assert_spin_locked(&old->lock); - new->i.inode = old->i.inode; - new->m.mnt = old->m.mnt; + new->inode = old->inode; + new->mnt = old->mnt; if (old->group) fsnotify_get_group(old->group); new->group = old->group; @@ -350,8 +469,8 @@ static int fsnotify_mark_destroy(void *ignored) synchronize_srcu(&fsnotify_mark_srcu); - list_for_each_entry_safe(mark, next, &private_destroy_list, destroy_list) { - list_del_init(&mark->destroy_list); + list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) { + list_del_init(&mark->g_list); fsnotify_put_mark(mark); } |