cifs: support RENAME_NOREPLACE

This flag gives CIFS the ability to support its native rename semantics.

Implementation is simple: just bail out before trying to hack around the
noreplace semantics.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 15 insertions, 5 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 888398067420..ac4f260155c8 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -848,7 +848,7 @@ const struct inode_operations cifs_dir_inode_ops = {
         .link = cifs_hardlink,
         .mkdir = cifs_mkdir,
         .rmdir = cifs_rmdir,
-        .rename = cifs_rename,
+        .rename2 = cifs_rename2,
         .permission = cifs_permission,
 /*      revalidate:cifs_revalidate,   */
         .setattr = cifs_setattr,
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 70f178a7c759..ed58c88f5f5d 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -68,8 +68,8 @@ extern int cifs_hardlink(struct dentry *, struct inode *, struct dentry *);
 extern int cifs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 extern int cifs_mkdir(struct inode *, struct dentry *, umode_t);
 extern int cifs_rmdir(struct inode *, struct dentry *);
-extern int cifs_rename(struct inode *, struct dentry *, struct inode *,
-                       struct dentry *);
+extern int cifs_rename2(struct inode *, struct dentry *, struct inode *,
+                        struct dentry *, unsigned int);
 extern int cifs_revalidate_file_attr(struct file *filp);
 extern int cifs_revalidate_dentry_attr(struct dentry *);
 extern int cifs_revalidate_file(struct file *filp);
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index a174605f6afa..bec0a0831be6 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1627,8 +1627,9 @@ do_rename_exit:
 }
 
 int
-cifs_rename(struct inode *source_dir, struct dentry *source_dentry,
-            struct inode *target_dir, struct dentry *target_dentry)
+cifs_rename2(struct inode *source_dir, struct dentry *source_dentry,
+             struct inode *target_dir, struct dentry *target_dentry,
+             unsigned int flags)
 {
         char *from_name = NULL;
         char *to_name = NULL;
@@ -1640,6 +1641,9 @@ cifs_rename(struct inode *source_dir, struct dentry *source_dentry,
         unsigned int xid;
         int rc, tmprc;
 
+        if (flags & ~RENAME_NOREPLACE)
+                return -EINVAL;
+
         cifs_sb = CIFS_SB(source_dir->i_sb);
         tlink = cifs_sb_tlink(cifs_sb);
         if (IS_ERR(tlink))
@@ -1667,6 +1671,12 @@ cifs_rename(struct inode *source_dir, struct dentry *source_dentry,
         rc = cifs_do_rename(xid, source_dentry, from_name, target_dentry,
                             to_name);
 
+        /*
+         * No-replace is the natural behavior for CIFS, so skip unlink hacks.
+         */
+        if (flags & RENAME_NOREPLACE)
+                goto cifs_rename_exit;
+
         if (rc == -EEXIST && tcon->unix_ext) {
                 /*
                  * Are src and dst hardlinks of same inode? We can only tell