[CIFS] remove redundant path walking in dfs_do_refmount

Reviewed-by: Dave Howells <dhowells@redhat.com>
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 11 insertions, 17 deletions

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index ac19a6f3dae0..dc1ed50ea06e 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -230,28 +230,22 @@ compose_mount_options_err:
         goto compose_mount_options_out;
 }
 
-
-static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
-                struct dentry *dentry, const struct dfs_info3_param *ref)
+/**
+ * cifs_dfs_do_refmount - mounts specified path using provided refferal
+ * @cifs_sb:            parent/root superblock
+ * @fullpath:           full path in UNC format
+ * @ref:                server's referral
+ */
+static struct vfsmount *cifs_dfs_do_refmount(struct cifs_sb_info *cifs_sb,
+                const char *fullpath, const struct dfs_info3_param *ref)
 {
-        struct cifs_sb_info *cifs_sb;
         struct vfsmount *mnt;
         char *mountdata;
         char *devname = NULL;
-        char *fullpath;
-
-        cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
-        /*
-         * this function gives us a path with a double backslash prefix. We
-         * require a single backslash for DFS.
-         */
-        fullpath = build_path_from_dentry(dentry);
-        if (!fullpath)
-                return ERR_PTR(-ENOMEM);
 
+        /* strip first '\' from fullpath */
         mountdata = cifs_compose_mount_options(cifs_sb->mountdata,
                         fullpath + 1, ref, &devname);
-        kfree(fullpath);
 
         if (IS_ERR(mountdata))
                 return (struct vfsmount *)mountdata;
@@ -357,8 +351,8 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
                         rc = -EINVAL;
                         goto out_err;
                 }
-                mnt = cifs_dfs_do_refmount(nd->path.mnt,
-                                nd->path.dentry, referrals + i);
+                mnt = cifs_dfs_do_refmount(cifs_sb,
+                                full_path, referrals + i);
                 cFYI(1, "%s: cifs_dfs_do_refmount:%s , mnt:%p", __func__,
                                         referrals[i].node_name, mnt);