ovl: split out ovl_get_workpath() from ovl_fill_super()

It's okay to get rid of the intermediate error label due to ufs being
zeroed on allocation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index c1abd66..6d02ca3 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -860,6 +860,41 @@ out:
        return err;
 }
 
+static int ovl_get_workpath(struct ovl_fs *ufs, struct path *upperpath,
+                           struct path *workpath)
+{
+       int err;
+
+       err = ovl_mount_dir(ufs->config.workdir, workpath);
+       if (err)
+               goto out;
+
+       err = -EINVAL;
+       if (upperpath->mnt != workpath->mnt) {
+               pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
+               goto out;
+       }
+       if (!ovl_workdir_ok(workpath->dentry, upperpath->dentry)) {
+               pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
+               goto out;
+       }
+
+       err = -EBUSY;
+       if (ovl_inuse_trylock(workpath->dentry)) {
+               ufs->workdir_locked = true;
+       } else if (ufs->config.index) {
+               pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
+               goto out;
+       } else {
+               pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+       }
+
+       ufs->workbasedir = workpath->dentry;
+       err = 0;
+out:
+       return err;
+}
+
 static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct path upperpath = { };
@@ -907,31 +942,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
                if (err)
                        goto out_unlock_upperdentry;
 
-               err = ovl_mount_dir(ufs->config.workdir, &workpath);
+               err = ovl_get_workpath(ufs, &upperpath, &workpath);
                if (err)
-                       goto out_unlock_upperdentry;
-
-               err = -EINVAL;
-               if (upperpath.mnt != workpath.mnt) {
-                       pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
-                       goto out_put_workpath;
-               }
-               if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) {
-                       pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
-                       goto out_put_workpath;
-               }
-
-               err = -EBUSY;
-               if (ovl_inuse_trylock(workpath.dentry)) {
-                       ufs->workdir_locked = true;
-               } else if (ufs->config.index) {
-                       pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
-                       goto out_put_workpath;
-               } else {
-                       pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
-               }
+                       goto out_unlock_workdentry;
 
-               ufs->workbasedir = workpath.dentry;
                sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth;
        }
        err = -ENOMEM;
@@ -1203,7 +1217,6 @@ out_free_lowertmp:
 out_unlock_workdentry:
        if (ufs->workdir_locked)
                ovl_inuse_unlock(workpath.dentry);
-out_put_workpath:
        path_put(&workpath);
 out_unlock_upperdentry:
        if (ufs->upperdir_locked)