1 files changed, 36 insertions, 32 deletions

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 3970392..3680242 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);
 	}