ovl: rearrange code in ovl_copy_up_locked()

As preparation to implementing copy up with O_TMPFILE,
name the variable for dentry before final rename 'temp' and
assign it to 'newdentry' only after rename.

Also lookup upper dentry before looking up temp dentry and
move ovl_set_timestamps() into ovl_copy_up_locked(), because
that is going to be more convenient for upcoming change.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index f57043d..01e3327 100644 (file)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -232,12 +232,14 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
 
 static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
                              struct dentry *dentry, struct path *lowerpath,
-                             struct kstat *stat, const char *link)
+                             struct kstat *stat, const char *link,
+                             struct kstat *pstat)
 {
        struct inode *wdir = workdir->d_inode;
        struct inode *udir = upperdir->d_inode;
        struct dentry *newdentry = NULL;
        struct dentry *upper = NULL;
+       struct dentry *temp = NULL;
        int err;
        const struct cred *old_creds = NULL;
        struct cred *new_creds = NULL;
@@ -248,25 +250,25 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
                .link = link
        };
 
-       newdentry = ovl_lookup_temp(workdir, dentry);
-       err = PTR_ERR(newdentry);
-       if (IS_ERR(newdentry))
-               goto out;
-
        upper = lookup_one_len(dentry->d_name.name, upperdir,
                               dentry->d_name.len);
        err = PTR_ERR(upper);
        if (IS_ERR(upper))
-               goto out1;
+               goto out;
 
        err = security_inode_copy_up(dentry, &new_creds);
        if (err < 0)
-               goto out2;
+               goto out1;
 
        if (new_creds)
                old_creds = override_creds(new_creds);
 
-       err = ovl_create_real(wdir, newdentry, &cattr, NULL, true);
+       temp = ovl_lookup_temp(workdir, dentry);
+       err = PTR_ERR(temp);
+       if (IS_ERR(temp))
+               goto out1;
+
+       err = ovl_create_real(wdir, temp, &cattr, NULL, true);
 
        if (new_creds) {
                revert_creds(old_creds);
@@ -281,39 +283,42 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
 
                ovl_path_upper(dentry, &upperpath);
                BUG_ON(upperpath.dentry != NULL);
-               upperpath.dentry = newdentry;
+               upperpath.dentry = temp;
 
                err = ovl_copy_up_data(lowerpath, &upperpath, stat->size);
                if (err)
                        goto out_cleanup;
        }
 
-       err = ovl_copy_xattr(lowerpath->dentry, newdentry);
+       err = ovl_copy_xattr(lowerpath->dentry, temp);
        if (err)
                goto out_cleanup;
 
-       inode_lock(newdentry->d_inode);
-       err = ovl_set_attr(newdentry, stat);
-       inode_unlock(newdentry->d_inode);
+       inode_lock(temp->d_inode);
+       err = ovl_set_attr(temp, stat);
+       inode_unlock(temp->d_inode);
        if (err)
                goto out_cleanup;
 
-       err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
+       err = ovl_do_rename(wdir, temp, udir, upper, 0);
        if (err)
                goto out_cleanup;
 
+       newdentry = dget(temp);
        ovl_dentry_update(dentry, newdentry);
        ovl_inode_update(d_inode(dentry), d_inode(newdentry));
-       newdentry = NULL;
+
+       /* Restore timestamps on parent (best effort) */
+       ovl_set_timestamps(upperdir, pstat);
 out2:
-       dput(upper);
+       dput(temp);
 out1:
-       dput(newdentry);
+       dput(upper);
 out:
        return err;
 
 out_cleanup:
-       ovl_cleanup(wdir, newdentry);
+       ovl_cleanup(wdir, temp);
        goto out2;
 }
 
@@ -368,11 +373,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
        }
 
        err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
-                                stat, link);
-       if (!err) {
-               /* Restore timestamps on parent (best effort) */
-               ovl_set_timestamps(upperdir, &pstat);
-       }
+                                stat, link, &pstat);
 out_unlock:
        unlock_rename(workdir, upperdir);
        do_delayed_call(&done);