fsnotify: duplicate fsnotify_mark_entry data between 2 marks

Simple copy fsnotify information from one mark to another in preparation
for the second mark to replace the first.

Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 11 insertions, 1 deletions

diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 0399bcbe09c8..a13cf9e9233a 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -282,12 +282,20 @@ struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *grou
         return NULL;
 }
 
+void fsnotify_duplicate_mark(struct fsnotify_mark_entry *new, struct fsnotify_mark_entry *old)
+{
+        assert_spin_locked(&old->lock);
+        new->inode = old->inode;
+        new->group = old->group;
+        new->mask = old->mask;
+        new->free_mark = old->free_mark;
+}
+
 /*
  * Nothing fancy, just initialize lists and locks and counters.
  */
 void fsnotify_init_mark(struct fsnotify_mark_entry *entry,
                         void (*free_mark)(struct fsnotify_mark_entry *entry))
-
 {
         spin_lock_init(&entry->lock);
         atomic_set(&entry->refcnt, 1);
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 8f8341e9f021..390516732956 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -342,6 +342,8 @@ extern void fsnotify_recalc_inode_mask(struct inode *inode);
 extern void fsnotify_init_mark(struct fsnotify_mark_entry *entry, void (*free_mark)(struct fsnotify_mark_entry *entry));
 /* find (and take a reference) to a mark associated with group and inode */
 extern struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group, struct inode *inode);
+/* copy the values from old into new */
+extern void fsnotify_duplicate_mark(struct fsnotify_mark_entry *new, struct fsnotify_mark_entry *old);
 /* attach the mark to both the group and the inode */
 extern int fsnotify_add_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group, struct inode *inode);
 /* given a mark, flag it to be freed when all references are dropped */