fanotify: limit the number of marks in a single fanotify group
[linux-2.6.git] / fs / notify / fanotify / fanotify_user.c
index 43d66d9..1d33d7d 100644 (file)
@@ -17,6 +17,7 @@
 #include <asm/ioctls.h>
 
 #define FANOTIFY_DEFAULT_MAX_EVENTS    16384
+#define FANOTIFY_DEFAULT_MAX_MARKS     8192
 
 extern const struct fsnotify_ops fanotify_fsnotify_ops;
 
@@ -584,6 +585,9 @@ static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
        if (!fsn_mark) {
                int ret;
 
+               if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+                       return -ENOSPC;
+
                fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
                if (!fsn_mark)
                        return -ENOMEM;
@@ -626,6 +630,9 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
        if (!fsn_mark) {
                int ret;
 
+               if (atomic_read(&group->num_marks) > group->fanotify_data.max_marks)
+                       return -ENOSPC;
+
                fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
                if (!fsn_mark)
                        return -ENOMEM;
@@ -700,6 +707,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
                group->max_events = FANOTIFY_DEFAULT_MAX_EVENTS;
        }
 
+       group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
+
        fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
        if (fd < 0)
                goto out_put_group;