Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 15 insertions, 15 deletions

diff --git a/fs/inotify.c b/fs/inotify.c
index 2c5b92152876..690e72595e6e 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);