summaryrefslogtreecommitdiffstats
path: root/fs/inotify.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/inotify.c')
-rw-r--r--fs/inotify.c30
1 files changed, 15 insertions, 15 deletions
diff --git a/fs/inotify.c b/fs/inotify.c
index 2c5b9215287..690e72595e6 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -168,20 +168,14 @@ static void set_dentry_child_flags(struct inode *inode, int watched)
struct dentry *child;
list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
- if (!child->d_inode) {
- WARN_ON(child->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
+ if (!child->d_inode)
continue;
- }
+
spin_lock(&child->d_lock);
- if (watched) {
- WARN_ON(child->d_flags &
- DCACHE_INOTIFY_PARENT_WATCHED);
+ if (watched)
child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- } else {
- WARN_ON(!(child->d_flags &
- DCACHE_INOTIFY_PARENT_WATCHED));
- child->d_flags&=~DCACHE_INOTIFY_PARENT_WATCHED;
- }
+ else
+ child->d_flags &=~DCACHE_INOTIFY_PARENT_WATCHED;
spin_unlock(&child->d_lock);
}
}
@@ -253,7 +247,6 @@ void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
if (!inode)
return;
- WARN_ON(entry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
spin_lock(&entry->d_lock);
parent = entry->d_parent;
if (parent->d_inode && inotify_inode_watched(parent->d_inode))
@@ -627,6 +620,7 @@ s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
struct inode *inode, u32 mask)
{
int ret = 0;
+ int newly_watched;
/* don't allow invalid bits: we don't want flags set */
mask &= IN_ALL_EVENTS | IN_ONESHOT;
@@ -653,12 +647,18 @@ s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
*/
watch->inode = igrab(inode);
- if (!inotify_inode_watched(inode))
- set_dentry_child_flags(inode, 1);
-
/* Add the watch to the handle's and the inode's list */
+ newly_watched = !inotify_inode_watched(inode);
list_add(&watch->h_list, &ih->watches);
list_add(&watch->i_list, &inode->inotify_watches);
+ /*
+ * Set child flags _after_ adding the watch, so there is no race
+ * windows where newly instantiated children could miss their parent's
+ * watched flag.
+ */
+ if (newly_watched)
+ set_dentry_child_flags(inode, 1);
+
out:
mutex_unlock(&ih->mutex);
mutex_unlock(&inode->inotify_mutex);