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>

4 files changed, 30 insertions, 10 deletions

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index ca65f39dc8dc..31088a969351 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -396,7 +396,7 @@ try_again:
                 cachefiles_io_error(cache, "Rename security error %d", ret);
         } else {
                 ret = vfs_rename(dir->d_inode, rep,
-                                 cache->graveyard->d_inode, grave, NULL);
+                                 cache->graveyard->d_inode, grave, NULL, 0);
                 if (ret != 0 && ret != -ENOMEM)
                         cachefiles_io_error(cache,
                                             "Rename failed with error %d", ret);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index b167ca48b8ee..d4a9431ec73c 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -641,7 +641,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         }
         rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
                         lower_new_dir_dentry->d_inode, lower_new_dentry,
-                        NULL);
+                        NULL, 0);
         if (rc)
                 goto out_lock;
         if (target_inode)
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)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6d7be3f80356..915808b36df7 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1694,7 +1694,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
         if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
                 goto out_dput_new;
 
-        host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL);
+        host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
         if (!host_err) {
                 host_err = commit_metadata(tfhp);
                 if (!host_err)