1 files changed, 36 insertions, 32 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 3970392b2722..36802420d69a 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -148,13 +148,14 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
                          const unsigned char *file_name,
                          struct fsnotify_event **event)
 {
-        struct fsnotify_group *group = inode_mark->group;
-        __u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
-        __u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+        struct fsnotify_group *group = NULL;
+        __u32 inode_test_mask = 0;
+        __u32 vfsmount_test_mask = 0;
 
-        pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p"
-                 " data_is=%d cookie=%d event=%p\n", __func__, group, to_tell,
-                 mnt, inode_mark, mask, data, data_is, cookie, *event);
+        if (unlikely(!inode_mark && !vfsmount_mark)) {
+                BUG();
+                return 0;
+        }
 
         /* clear ignored on inode modification */
         if (mask & FS_MODIFY) {
@@ -168,18 +169,29 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
 
         /* does the inode mark tell us to do something? */
         if (inode_mark) {
+                group = inode_mark->group;
+                inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
                 inode_test_mask &= inode_mark->mask;
                 inode_test_mask &= ~inode_mark->ignored_mask;
         }
 
         /* does the vfsmount_mark tell us to do something? */
         if (vfsmount_mark) {
+                vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+                group = vfsmount_mark->group;
                 vfsmount_test_mask &= vfsmount_mark->mask;
                 vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
                 if (inode_mark)
                         vfsmount_test_mask &= ~inode_mark->ignored_mask;
         }
 
+        pr_debug("%s: group=%p to_tell=%p mnt=%p mask=%x inode_mark=%p"
+                 " inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x"
+                 " data=%p data_is=%d cookie=%d event=%p\n",
+                 __func__, group, to_tell, mnt, mask, inode_mark,
+                 inode_test_mask, vfsmount_mark, vfsmount_test_mask, data,
+                 data_is, cookie, *event);
+
         if (!inode_test_mask && !vfsmount_test_mask)
                 return 0;
 
@@ -207,13 +219,12 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
 int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
              const unsigned char *file_name, u32 cookie)
 {
-        struct hlist_node *inode_node, *vfsmount_node;
+        struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;
         struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
         struct fsnotify_group *inode_group, *vfsmount_group;
         struct fsnotify_event *event = NULL;
         struct vfsmount *mnt;
         int idx, ret = 0;
-        bool used_inode = false, used_vfsmount = false;
         /* global tests shouldn't care about events on child only the specific event */
         __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
 
@@ -238,57 +249,50 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
             (test_mask & to_tell->i_fsnotify_mask))
                 inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
                                               &fsnotify_mark_srcu);
-        else
-                inode_node = NULL;
 
-        if (mnt) {
-                if ((mask & FS_MODIFY) ||
-                    (test_mask & mnt->mnt_fsnotify_mask))
-                        vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
-                                                         &fsnotify_mark_srcu);
-                else
-                        vfsmount_node = NULL;
-        } else {
-                mnt = NULL;
-                vfsmount_node = NULL;
+        if (mnt && ((mask & FS_MODIFY) ||
+                    (test_mask & mnt->mnt_fsnotify_mask))) {
+                vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
+                                                 &fsnotify_mark_srcu);
+                inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
+                                              &fsnotify_mark_srcu);
         }
 
         while (inode_node || vfsmount_node) {
+                inode_group = vfsmount_group = NULL;
+
                 if (inode_node) {
                         inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
                                                  struct fsnotify_mark, i.i_list);
                         inode_group = inode_mark->group;
-                } else
-                        inode_group = (void *)-1;
+                }
 
                 if (vfsmount_node) {
                         vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
                                                         struct fsnotify_mark, m.m_list);
                         vfsmount_group = vfsmount_mark->group;
-                } else
-                        vfsmount_group = (void *)-1;
+                }
 
-                if (inode_group < vfsmount_group) {
+                if (inode_group > vfsmount_group) {
                         /* handle inode */
                         send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
                                       data_is, cookie, file_name, &event);
-                        used_inode = true;
-                } else if (vfsmount_group < inode_group) {
+                        /* we didn't use the vfsmount_mark */
+                        vfsmount_group = NULL;
+                } else if (vfsmount_group > inode_group) {
                         send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
                                       data_is, cookie, file_name, &event);
-                        used_vfsmount = true;
+                        inode_group = NULL;
                 } else {
                         send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
                                       mask, data, data_is, cookie, file_name,
                                       &event);
-                        used_vfsmount = true;
-                        used_inode = true;
                 }
 
-                if (used_inode)
+                if (inode_group)
                         inode_node = srcu_dereference(inode_node->next,
                                                       &fsnotify_mark_srcu);
-                if (used_vfsmount)
+                if (vfsmount_group)
                         vfsmount_node = srcu_dereference(vfsmount_node->next,
                                                          &fsnotify_mark_srcu);
         }