ceph: use ceph_mdsc_build_path instead of clone_dentry_name

While it may be slightly more efficient, it's probably not worthwhile to
optimize for the case that clone_dentry_name handles. We can get the
same result by just calling ceph_mdsc_build_path when the parent isn't
locked, with less code duplication.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b01e2043b1b27390a5d00ad0dce04f3f638fa656..7af722834348c118baf99ab1d7bec307452cc736 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2172,56 +2172,20 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
        return path;
 }
 
-/* Duplicate the dentry->d_name.name safely */
-static int clone_dentry_name(struct dentry *dentry, const char **ppath,
-                            int *ppathlen)
-{
-       u32 len;
-       char *name;
-
-retry:
-       len = READ_ONCE(dentry->d_name.len);
-       name = kmalloc(len + 1, GFP_NOFS);
-       if (!name)
-               return -ENOMEM;
-
-       spin_lock(&dentry->d_lock);
-       if (dentry->d_name.len != len) {
-               spin_unlock(&dentry->d_lock);
-               kfree(name);
-               goto retry;
-       }
-       memcpy(name, dentry->d_name.name, len);
-       spin_unlock(&dentry->d_lock);
-
-       name[len] = '\0';
-       *ppath = name;
-       *ppathlen = len;
-       return 0;
-}
-
 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
                             const char **ppath, int *ppathlen, u64 *pino,
                             bool *pfreepath, bool parent_locked)
 {
-       int ret;
        char *path;
 
        rcu_read_lock();
        if (!dir)
                dir = d_inode_rcu(dentry->d_parent);
-       if (dir && ceph_snap(dir) == CEPH_NOSNAP) {
+       if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
                *pino = ceph_ino(dir);
                rcu_read_unlock();
-               if (parent_locked) {
-                       *ppath = dentry->d_name.name;
-                       *ppathlen = dentry->d_name.len;
-               } else {
-                       ret = clone_dentry_name(dentry, ppath, ppathlen);
-                       if (ret)
-                               return ret;
-                       *pfreepath = true;
-               }
+               *ppath = dentry->d_name.name;
+               *ppathlen = dentry->d_name.len;
                return 0;
        }
        rcu_read_unlock();