[CIFS] fix memory leak in cifs session info struct on reconnect

[sfrench/cifs-2.6.git] / fs / inotify.c

diff --git a/fs/inotify.c b/fs/inotify.c
index 0ee39ef591c6dac600a4cb07d2741be546becc38..732ec4bd5774507f8c06c6e05cc90d4d2004a84b 100644 (file)
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -38,17 +38,16 @@
 #include <asm/ioctls.h>
 
 static atomic_t inotify_cookie;
-static atomic_t inotify_watches;
 
-static kmem_cache_t *watch_cachep;
-static kmem_cache_t *event_cachep;
+static kmem_cache_t *watch_cachep __read_mostly;
+static kmem_cache_t *event_cachep __read_mostly;
 
-static struct vfsmount *inotify_mnt;
+static struct vfsmount *inotify_mnt __read_mostly;
 
 /* these are configurable via /proc/sys/fs/inotify/ */
-int inotify_max_user_instances;
-int inotify_max_user_watches;
-int inotify_max_queued_events;
+int inotify_max_user_instances __read_mostly;
+int inotify_max_user_watches __read_mostly;
+int inotify_max_queued_events __read_mostly;
 
 /*
  * Lock ordering:
@@ -380,6 +379,48 @@ static int find_inode(const char __user *dirname, struct nameidata *nd,
        return error;
 }
 
+/*
+ * inotify_inode_watched - returns nonzero if there are watches on this inode
+ * and zero otherwise.  We call this lockless, we do not care if we race.
+ */
+static inline int inotify_inode_watched(struct inode *inode)
+{
+       return !list_empty(&inode->inotify_watches);
+}
+
+/*
+ * Get child dentry flag into synch with parent inode.
+ * Flag should always be clear for negative dentrys.
+ */
+static void set_dentry_child_flags(struct inode *inode, int watched)
+{
+       struct dentry *alias;
+
+       spin_lock(&dcache_lock);
+       list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+               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);
+                               continue;
+                       }
+                       spin_lock(&child->d_lock);
+                       if (watched) {
+                               WARN_ON(child->d_flags &
+                                               DCACHE_INOTIFY_PARENT_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;
+                       }
+                       spin_unlock(&child->d_lock);
+               }
+       }
+       spin_unlock(&dcache_lock);
+}
+
 /*
  * create_watch - creates a watch on the given device.
  *
@@ -426,7 +467,6 @@ static struct inotify_watch *create_watch(struct inotify_device *dev,
        get_inotify_watch(watch);
 
        atomic_inc(&dev->user->inotify_watches);
-       atomic_inc(&inotify_watches);
 
        return watch;
 }
@@ -458,8 +498,10 @@ static void remove_watch_no_event(struct inotify_watch *watch,
        list_del(&watch->i_list);
        list_del(&watch->d_list);
 
+       if (!inotify_inode_watched(watch->inode))
+               set_dentry_child_flags(watch->inode, 0);
+
        atomic_dec(&dev->user->inotify_watches);
-       atomic_dec(&inotify_watches);
        idr_remove(&dev->idr, watch->wd);
        put_inotify_watch(watch);
 }
@@ -481,16 +523,39 @@ static void remove_watch(struct inotify_watch *watch,struct inotify_device *dev)
        remove_watch_no_event(watch, dev);
 }
 
+/* Kernel API */
+
 /*
- * inotify_inode_watched - returns nonzero if there are watches on this inode
- * and zero otherwise.  We call this lockless, we do not care if we race.
+ * inotify_d_instantiate - instantiate dcache entry for inode
  */
-static inline int inotify_inode_watched(struct inode *inode)
+void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
 {
-       return !list_empty(&inode->inotify_watches);
+       struct dentry *parent;
+
+       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))
+               entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
+       spin_unlock(&entry->d_lock);
 }
 
-/* Kernel API */
+/*
+ * inotify_d_move - dcache entry has been moved
+ */
+void inotify_d_move(struct dentry *entry)
+{
+       struct dentry *parent;
+
+       parent = entry->d_parent;
+       if (inotify_inode_watched(parent->d_inode))
+               entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
+       else
+               entry->d_flags &= ~DCACHE_INOTIFY_PARENT_WATCHED;
+}
 
 /**
  * inotify_inode_queue_event - queue an event to all watches on this inode
@@ -538,7 +603,7 @@ void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask,
        struct dentry *parent;
        struct inode *inode;
 
-       if (!atomic_read (&inotify_watches))
+       if (!(dentry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED))
                return;
 
        spin_lock(&dentry->d_lock);
@@ -783,7 +848,11 @@ static int inotify_release(struct inode *ignored, struct file *file)
                inode = watch->inode;
                mutex_lock(&inode->inotify_mutex);
                mutex_lock(&dev->mutex);
-               remove_watch_no_event(watch, dev);
+
+               /* make sure we didn't race with another list removal */
+               if (likely(idr_find(&dev->idr, watch->wd)))
+                       remove_watch_no_event(watch, dev);
+
                mutex_unlock(&dev->mutex);
                mutex_unlock(&inode->inotify_mutex);
                put_inotify_watch(watch);
@@ -825,8 +894,7 @@ static int inotify_ignore(struct inotify_device *dev, s32 wd)
        mutex_lock(&dev->mutex);
 
        /* make sure that we did not race */
-       watch = idr_find(&dev->idr, wd);
-       if (likely(watch))
+       if (likely(idr_find(&dev->idr, wd) == watch))
                remove_watch(watch, dev);
 
        mutex_unlock(&dev->mutex);
@@ -855,7 +923,7 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
        return ret;
 }
 
-static struct file_operations inotify_fops = {
+static const struct file_operations inotify_fops = {
        .poll           = inotify_poll,
        .read           = inotify_read,
        .release        = inotify_release,
@@ -993,6 +1061,9 @@ asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)
                goto out;
        }
 
+       if (!inotify_inode_watched(inode))
+               set_dentry_child_flags(inode, 1);
+
        /* Add the watch to the device's and the inode's list */
        list_add(&watch->d_list, &dev->watches);
        list_add(&watch->i_list, &inode->inotify_watches);
@@ -1065,7 +1136,6 @@ static int __init inotify_setup(void)
        inotify_max_user_watches = 8192;
 
        atomic_set(&inotify_cookie, 0);
-       atomic_set(&inotify_watches, 0);
 
        watch_cachep = kmem_cache_create("inotify_watch_cache",
                                         sizeof(struct inotify_watch),