Unionfs: create whiteout in correct dir after rename with copyup

Fixes bug #625: a file renamed/moved into a directory, if resulted in a
copyup with a whiteout creation, could cause the whiteout to be created in
the wrong dir.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index 800d9ee74c41de119a2a3ccdfb28a159268aa9a6..92f04073680c701103da172834ae1e91a61f7787 100644 (file)
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -162,7 +162,7 @@ static int do_unionfs_rename(struct inode *old_dir,
                             struct dentry *new_parent)
 {
        int err = 0;
-       int bindex, bwh_old;
+       int bindex;
        int old_bstart, old_bend;
        int new_bstart, new_bend;
        int do_copyup = -1;
@@ -171,7 +171,6 @@ static int do_unionfs_rename(struct inode *old_dir,
        int revert = 0;
 
        old_bstart = dbstart(old_dentry);
-       bwh_old = old_bstart;
        old_bend = dbend(old_dentry);
 
        new_bstart = dbstart(new_dentry);
@@ -242,7 +241,19 @@ static int do_unionfs_rename(struct inode *old_dir,
                        /* if copyup failed, try next branch to the left */
                        if (err)
                                continue;
-                       bwh_old = bindex;
+                       /*
+                        * create whiteout before calling __unionfs_rename
+                        * because the latter will change the old_dentry's
+                        * lower name and parent dir, resulting in the
+                        * whiteout getting created in the wrong dir.
+                        */
+                       err = create_whiteout(old_dentry, bindex);
+                       if (err) {
+                               printk(KERN_ERR "unionfs: can't create a "
+                                      "whiteout for %s in rename (err=%d)\n",
+                                      old_dentry->d_name.name, err);
+                               continue;
+                       }
                        err = __unionfs_rename(old_dir, old_dentry, old_parent,
                                               new_dir, new_dentry, new_parent,
                                               bindex);
@@ -260,16 +271,10 @@ static int do_unionfs_rename(struct inode *old_dir,
        /*
         * Create whiteout for source, only if:
         * (1) There is more than one underlying instance of source.
-        * (2) We did a copy_up
+        * (We did a copy_up is taken care of above).
         */
-       if ((old_bstart != old_bend) || (do_copyup != -1)) {
-               if (bwh_old < 0) {
-                       printk(KERN_ERR "unionfs: rename error (bwh_old=%d)\n",
-                              bwh_old);
-                       err = -EIO;
-                       goto out;
-               }
-               err = create_whiteout(old_dentry, bwh_old);
+       if ((old_bstart != old_bend) && (do_copyup == -1)) {
+               err = create_whiteout(old_dentry, old_bstart);
                if (err) {
                        /* can't fix anything now, so we exit with -EIO */
                        printk(KERN_ERR "unionfs: can't create a whiteout for "