diff options
| -rw-r--r-- | fs/notify/mark.c | 36 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 1 |
2 files changed, 23 insertions, 14 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 1f611e4eab53..647c49c20467 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -154,20 +154,23 @@ static void fsnotify_put_inode_ref(struct inode *inode) iput(inode); } -static void fsnotify_get_sb_watchers(struct fsnotify_mark_connector *conn) +/* + * Grab or drop watched objects reference depending on whether the connector + * is attached and has any marks attached. + */ +static void fsnotify_update_sb_watchers(struct super_block *sb, + struct fsnotify_mark_connector *conn) { - struct super_block *sb = fsnotify_connector_sb(conn); + bool is_watched = conn->flags & FSNOTIFY_CONN_FLAG_IS_WATCHED; + bool has_marks = conn->obj && !hlist_empty(&conn->list); - if (sb) + if (has_marks && !is_watched) { + conn->flags |= FSNOTIFY_CONN_FLAG_IS_WATCHED; fsnotify_get_sb_watched_objects(sb); -} - -static void fsnotify_put_sb_watchers(struct fsnotify_mark_connector *conn) -{ - struct super_block *sb = fsnotify_connector_sb(conn); - - if (sb) + } else if (!has_marks && is_watched) { + conn->flags &= ~FSNOTIFY_CONN_FLAG_IS_WATCHED; fsnotify_put_sb_watched_objects(sb); + } } /* @@ -266,6 +269,7 @@ static void *fsnotify_detach_connector_from_object( unsigned int *type) { fsnotify_connp_t *connp = fsnotify_object_connp(conn->obj, conn->type); + struct super_block *sb = fsnotify_connector_sb(conn); struct inode *inode = NULL; *type = conn->type; @@ -285,10 +289,10 @@ static void *fsnotify_detach_connector_from_object( fsnotify_conn_sb(conn)->s_fsnotify_mask = 0; } - fsnotify_put_sb_watchers(conn); rcu_assign_pointer(*connp, NULL); conn->obj = NULL; conn->type = FSNOTIFY_OBJ_TYPE_DETACHED; + fsnotify_update_sb_watchers(sb, conn); return inode; } @@ -340,6 +344,11 @@ void fsnotify_put_mark(struct fsnotify_mark *mark) objp = fsnotify_detach_connector_from_object(conn, &type); free_conn = true; } else { + struct super_block *sb = fsnotify_connector_sb(conn); + + /* Update watched objects after detaching mark */ + if (sb) + fsnotify_update_sb_watchers(sb, conn); objp = __fsnotify_recalc_mask(conn); type = conn->type; } @@ -581,10 +590,7 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, if (cmpxchg(connp, NULL, conn)) { /* Someone else created list structure for us */ kmem_cache_free(fsnotify_mark_connector_cachep, conn); - return 0; } - - fsnotify_get_sb_watchers(conn); return 0; } @@ -624,6 +630,7 @@ out: static int fsnotify_add_mark_list(struct fsnotify_mark *mark, void *obj, unsigned int obj_type, int add_flags) { + struct super_block *sb = fsnotify_object_sb(obj, obj_type); struct fsnotify_mark *lmark, *last = NULL; struct fsnotify_mark_connector *conn; fsnotify_connp_t *connp; @@ -673,6 +680,7 @@ restart: /* mark should be the last entry. last is the current last entry */ hlist_add_behind_rcu(&mark->obj_list, &last->obj_list); added: + fsnotify_update_sb_watchers(sb, conn); /* * Since connector is attached to object using cmpxchg() we are * guaranteed that connector initialization is fully visible by anyone diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index face68fcf850..83004d9e07a3 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -465,6 +465,7 @@ FSNOTIFY_ITER_FUNCS(sb, SB) struct fsnotify_mark_connector { spinlock_t lock; unsigned short type; /* Type of object [lock] */ +#define FSNOTIFY_CONN_FLAG_IS_WATCHED 0x01 #define FSNOTIFY_CONN_FLAG_HAS_IREF 0x02 unsigned short flags; /* flags [lock] */ union { |