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>

1 files changed, 3 insertions, 39 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b01e2043b1b2..7af722834348 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2172,56 +2172,20 @@ retry:
         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();