ovl: return dentry from ovl_create_real()

Al Viro suggested to simplify callers of ovl_create_real() by
returning the created dentry (or ERR_PTR) from ovl_create_real().

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 5f4c78b..d3e9c1e 100644 (file)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -502,19 +502,12 @@ static int ovl_get_tmpfile(struct ovl_copy_up_ctx *c, struct dentry **tempp)
 
        if (c->tmpfile) {
                temp = ovl_do_tmpfile(c->workdir, c->stat.mode);
-               if (IS_ERR(temp))
-                       goto temp_err;
        } else {
-               temp = ovl_lookup_temp(c->workdir);
-               if (IS_ERR(temp))
-                       goto temp_err;
-
-               err = ovl_create_real(d_inode(c->workdir), temp, &cattr);
-               if (err) {
-                       dput(temp);
-                       goto out;
-               }
+               temp = ovl_create_real(d_inode(c->workdir),
+                                      ovl_lookup_temp(c->workdir), &cattr);
        }
+       if (IS_ERR(temp))
+               goto temp_err;
        err = 0;
        *tempp = temp;
 out:

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 0fb3ef8..425ddb0 100644 (file)
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -114,13 +114,17 @@ kill_whiteout:
        goto out;
 }
 
-int ovl_create_real(struct inode *dir, struct dentry *newdentry,
-                   struct ovl_cattr *attr)
+struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
+                              struct ovl_cattr *attr)
 {
        int err;
 
+       if (IS_ERR(newdentry))
+               return newdentry;
+
+       err = -ESTALE;
        if (newdentry->d_inode)
-               return -ESTALE;
+               goto out;
 
        if (attr->hardlink) {
                err = ovl_do_link(attr->hardlink, dir, newdentry);
@@ -157,7 +161,12 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry,
                 */
                err = -ENOENT;
        }
-       return err;
+out:
+       if (err) {
+               dput(newdentry);
+               return ERR_PTR(err);
+       }
+       return newdentry;
 }
 
 static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
@@ -224,14 +233,14 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
                attr->mode &= ~current_umask();
 
        inode_lock_nested(udir, I_MUTEX_PARENT);
-       newdentry = lookup_one_len(dentry->d_name.name, upperdir,
-                                  dentry->d_name.len);
+       newdentry = ovl_create_real(udir,
+                                   lookup_one_len(dentry->d_name.name,
+                                                  upperdir,
+                                                  dentry->d_name.len),
+                                   attr);
        err = PTR_ERR(newdentry);
        if (IS_ERR(newdentry))
                goto out_unlock;
-       err = ovl_create_real(udir, newdentry, attr);
-       if (err)
-               goto out_dput;
 
        if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry)) {
                /* Setting opaque here is just an optimization, allow to fail */
@@ -239,9 +248,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
        }
 
        ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink);
-       newdentry = NULL;
-out_dput:
-       dput(newdentry);
+       err = 0;
 out_unlock:
        inode_unlock(udir);
        return err;
@@ -280,15 +287,12 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
        if (upper->d_parent->d_inode != udir)
                goto out_unlock;
 
-       opaquedir = ovl_lookup_temp(workdir);
+       opaquedir = ovl_create_real(wdir, ovl_lookup_temp(workdir),
+                                   OVL_CATTR(stat.mode));
        err = PTR_ERR(opaquedir);
        if (IS_ERR(opaquedir))
                goto out_unlock;
 
-       err = ovl_create_real(wdir, opaquedir, OVL_CATTR(stat.mode));
-       if (err)
-               goto out_dput;
-
        err = ovl_copy_xattr(upper, opaquedir);
        if (err)
                goto out_cleanup;
@@ -318,7 +322,6 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
 
 out_cleanup:
        ovl_cleanup(wdir, opaquedir);
-out_dput:
        dput(opaquedir);
 out_unlock:
        unlock_rename(workdir, upperdir);
@@ -379,20 +382,16 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
        if (err)
                goto out;
 
-       newdentry = ovl_lookup_temp(workdir);
-       err = PTR_ERR(newdentry);
-       if (IS_ERR(newdentry))
-               goto out_unlock;
-
        upper = lookup_one_len(dentry->d_name.name, upperdir,
                               dentry->d_name.len);
        err = PTR_ERR(upper);
        if (IS_ERR(upper))
-               goto out_dput;
+               goto out_unlock;
 
-       err = ovl_create_real(wdir, newdentry, cattr);
-       if (err)
-               goto out_dput2;
+       newdentry = ovl_create_real(wdir, ovl_lookup_temp(workdir), cattr);
+       err = PTR_ERR(newdentry);
+       if (IS_ERR(newdentry))
+               goto out_dput;
 
        /*
         * mode could have been mutilated due to umask (e.g. sgid directory)
@@ -439,11 +438,9 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
                        goto out_cleanup;
        }
        ovl_instantiate(dentry, inode, newdentry, hardlink);
-       newdentry = NULL;
-out_dput2:
-       dput(upper);
+       err = 0;
 out_dput:
-       dput(newdentry);
+       dput(upper);
 out_unlock:
        unlock_rename(workdir, upperdir);
 out:
@@ -455,7 +452,8 @@ out:
 
 out_cleanup:
        ovl_cleanup(wdir, newdentry);
-       goto out_dput2;
+       dput(newdentry);
+       goto out_dput;
 }
 
 static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index aa82864..6bbde51 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -358,8 +358,8 @@ struct ovl_cattr {
 
 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
 
-int ovl_create_real(struct inode *dir, struct dentry *newdentry,
-                   struct ovl_cattr *attr);
+struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
+                              struct ovl_cattr *attr);
 int ovl_cleanup(struct inode *dir, struct dentry *dentry);
 
 /* copy_up.c */

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 286d367..704b373 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -611,9 +611,10 @@ retry:
                        goto retry;
                }
 
-               err = ovl_create_real(dir, work, OVL_CATTR(attr.ia_mode));
-               if (err)
-                       goto out_dput;
+               work = ovl_create_real(dir, work, OVL_CATTR(attr.ia_mode));
+               err = PTR_ERR(work);
+               if (IS_ERR(work))
+                       goto out_err;
 
                /*
                 * Try to remove POSIX ACL xattrs from workdir.  We are good if: