vfs: add renameat2 syscall

Add new renameat2 syscall, which is the same as renameat with an added
flags argument.

Pass flags to vfs_rename() and to i_op->rename() as well.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 27 insertions, 7 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 12b8f56ba942..ab4e48c4a80a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3980,6 +3980,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
  * @new_dir:	parent of destination
  * @new_dentry:	destination
  * @delegated_inode: returns an inode needing a delegation break
+ * @flags:	rename flags
  *
  * The caller must hold multiple mutexes--see lock_rename()).
  *
@@ -4023,7 +4024,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
  */
 int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	       struct inode *new_dir, struct dentry *new_dentry,
-	       struct inode **delegated_inode)
+	       struct inode **delegated_inode, unsigned int flags)
 {
 	int error;
 	bool is_dir = d_is_dir(old_dentry);
@@ -4048,6 +4049,9 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (!old_dir->i_op->rename)
 		return -EPERM;
 
+	if (flags && !old_dir->i_op->rename2)
+		return -EINVAL;
+
 	/*
 	 * If we are going to change the parent - check write permissions,
 	 * we'll need to flip '..'.
@@ -4093,7 +4097,13 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 				goto out;
 		}
 	}
-	error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
+	if (!flags) {
+		error = old_dir->i_op->rename(old_dir, old_dentry,
+					      new_dir, new_dentry);
+	} else {
+		error = old_dir->i_op->rename2(old_dir, old_dentry,
+					       new_dir, new_dentry, flags);
+	}
 	if (error)
 		goto out;
 
@@ -4118,8 +4128,8 @@ out:
 	return error;
 }
 
-SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
-		int, newdfd, const char __user *, newname)
+SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
+		int, newdfd, const char __user *, newname, unsigned int, flags)
 {
 	struct dentry *old_dir, *new_dir;
 	struct dentry *old_dentry, *new_dentry;
@@ -4131,6 +4141,10 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
 	unsigned int lookup_flags = 0;
 	bool should_retry = false;
 	int error;
+
+	if (flags)
+		return -EINVAL;
+
 retry:
 	from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
 	if (IS_ERR(from)) {
@@ -4202,8 +4216,8 @@ retry_deleg:
 	if (error)
 		goto exit5;
 	error = vfs_rename(old_dir->d_inode, old_dentry,
-				   new_dir->d_inode, new_dentry,
-				   &delegated_inode);
+			   new_dir->d_inode, new_dentry,
+			   &delegated_inode, flags);
 exit5:
 	dput(new_dentry);
 exit4:
@@ -4233,9 +4247,15 @@ exit:
 	return error;
 }
 
+SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
+		int, newdfd, const char __user *, newname)
+{
+	return sys_renameat2(olddfd, oldname, newdfd, newname, 0);
+}
+
 SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname)
 {
-	return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname);
+	return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
 int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link)