Merge tag 'kvm-arm-for-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / fs / overlayfs / dir.c

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 52f6de5..b3fc0a3 100644 (file)
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -596,21 +596,25 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
 {
        struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
        struct inode *dir = upperdir->d_inode;
-       struct dentry *upper = ovl_dentry_upper(dentry);
+       struct dentry *upper;
        int err;
 
        inode_lock_nested(dir, I_MUTEX_PARENT);
+       upper = lookup_one_len(dentry->d_name.name, upperdir,
+                              dentry->d_name.len);
+       err = PTR_ERR(upper);
+       if (IS_ERR(upper))
+               goto out_unlock;
+
        err = -ESTALE;
-       if (upper->d_parent == upperdir) {
-               /* Don't let d_delete() think it can reset d_inode */
-               dget(upper);
+       if (upper == ovl_dentry_upper(dentry)) {
                if (is_dir)
                        err = vfs_rmdir(dir, upper);
                else
                        err = vfs_unlink(dir, upper, NULL);
-               dput(upper);
                ovl_dentry_version_inc(dentry->d_parent);
        }
+       dput(upper);
 
        /*
         * Keeping this dentry hashed would mean having to release
@@ -620,6 +624,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
         */
        if (!err)
                d_drop(dentry);
+out_unlock:
        inode_unlock(dir);
 
        return err;
@@ -714,7 +719,6 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
        struct dentry *trap;
        bool old_opaque;
        bool new_opaque;
-       bool new_create = false;
        bool cleanup_whiteout = false;
        bool overwrite = !(flags & RENAME_EXCHANGE);
        bool is_dir = d_is_dir(old);
@@ -840,29 +844,38 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
 
        trap = lock_rename(new_upperdir, old_upperdir);
 
-       olddentry = ovl_dentry_upper(old);
-       newdentry = ovl_dentry_upper(new);
-       if (newdentry) {
+
+       olddentry = lookup_one_len(old->d_name.name, old_upperdir,
+                                  old->d_name.len);
+       err = PTR_ERR(olddentry);
+       if (IS_ERR(olddentry))
+               goto out_unlock;
+
+       err = -ESTALE;
+       if (olddentry != ovl_dentry_upper(old))
+               goto out_dput_old;
+
+       newdentry = lookup_one_len(new->d_name.name, new_upperdir,
+                                  new->d_name.len);
+       err = PTR_ERR(newdentry);
+       if (IS_ERR(newdentry))
+               goto out_dput_old;
+
+       err = -ESTALE;
+       if (ovl_dentry_upper(new)) {
                if (opaquedir) {
-                       newdentry = opaquedir;
-                       opaquedir = NULL;
+                       if (newdentry != opaquedir)
+                               goto out_dput;
                } else {
-                       dget(newdentry);
+                       if (newdentry != ovl_dentry_upper(new))
+                               goto out_dput;
                }
        } else {
-               new_create = true;
-               newdentry = lookup_one_len(new->d_name.name, new_upperdir,
-                                          new->d_name.len);
-               err = PTR_ERR(newdentry);
-               if (IS_ERR(newdentry))
-                       goto out_unlock;
+               if (!d_is_negative(newdentry) &&
+                   (!new_opaque || !ovl_is_whiteout(newdentry)))
+                       goto out_dput;
        }
 
-       err = -ESTALE;
-       if (olddentry->d_parent != old_upperdir)
-               goto out_dput;
-       if (newdentry->d_parent != new_upperdir)
-               goto out_dput;
        if (olddentry == trap)
                goto out_dput;
        if (newdentry == trap)
@@ -925,6 +938,8 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
 
 out_dput:
        dput(newdentry);
+out_dput_old:
+       dput(olddentry);
 out_unlock:
        unlock_rename(new_upperdir, old_upperdir);
 out_revert_creds: