diff options
Diffstat (limited to 'fs/notify/mark.c')
| -rw-r--r-- | fs/notify/mark.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index d2dd16cb5989..d593d4269561 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -82,6 +82,7 @@ #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/srcu.h> +#include <linux/ratelimit.h> #include <linux/atomic.h> @@ -481,7 +482,8 @@ int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b) } static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, - unsigned int type) + unsigned int type, + __kernel_fsid_t *fsid) { struct inode *inode = NULL; struct fsnotify_mark_connector *conn; @@ -493,6 +495,11 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, INIT_HLIST_HEAD(&conn->list); conn->type = type; conn->obj = connp; + /* Cache fsid of filesystem containing the object */ + if (fsid) + conn->fsid = *fsid; + else + conn->fsid.val[0] = conn->fsid.val[1] = 0; if (conn->type == FSNOTIFY_OBJ_TYPE_INODE) inode = igrab(fsnotify_conn_inode(conn)); /* @@ -544,7 +551,7 @@ out: */ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, fsnotify_connp_t *connp, unsigned int type, - int allow_dups) + int allow_dups, __kernel_fsid_t *fsid) { struct fsnotify_mark *lmark, *last = NULL; struct fsnotify_mark_connector *conn; @@ -553,15 +560,36 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, if (WARN_ON(!fsnotify_valid_obj_type(type))) return -EINVAL; + + /* Backend is expected to check for zero fsid (e.g. tmpfs) */ + if (fsid && WARN_ON_ONCE(!fsid->val[0] && !fsid->val[1])) + return -ENODEV; + restart: spin_lock(&mark->lock); conn = fsnotify_grab_connector(connp); if (!conn) { spin_unlock(&mark->lock); - err = fsnotify_attach_connector_to_object(connp, type); + err = fsnotify_attach_connector_to_object(connp, type, fsid); if (err) return err; goto restart; + } else if (fsid && (conn->fsid.val[0] || conn->fsid.val[1]) && + (fsid->val[0] != conn->fsid.val[0] || + fsid->val[1] != conn->fsid.val[1])) { + /* + * Backend is expected to check for non uniform fsid + * (e.g. btrfs), but maybe we missed something? + * Only allow setting conn->fsid once to non zero fsid. + * inotify and non-fid fanotify groups do not set nor test + * conn->fsid. + */ + pr_warn_ratelimited("%s: fsid mismatch on object of type %u: " + "%x.%x != %x.%x\n", __func__, conn->type, + fsid->val[0], fsid->val[1], + conn->fsid.val[0], conn->fsid.val[1]); + err = -EXDEV; + goto out_err; } /* is mark the first mark? */ @@ -606,7 +634,7 @@ out_err: */ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, fsnotify_connp_t *connp, unsigned int type, - int allow_dups) + int allow_dups, __kernel_fsid_t *fsid) { struct fsnotify_group *group = mark->group; int ret = 0; @@ -627,7 +655,7 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, fsnotify_get_mark(mark); /* for g_list */ spin_unlock(&mark->lock); - ret = fsnotify_add_mark_list(mark, connp, type, allow_dups); + ret = fsnotify_add_mark_list(mark, connp, type, allow_dups, fsid); if (ret) goto err; @@ -648,13 +676,13 @@ err: } int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_connp_t *connp, - unsigned int type, int allow_dups) + unsigned int type, int allow_dups, __kernel_fsid_t *fsid) { int ret; struct fsnotify_group *group = mark->group; mutex_lock(&group->mark_mutex); - ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups); + ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups, fsid); mutex_unlock(&group->mark_mutex); return ret; } |