Re: [PATCH 1/3] Introduce btrfs_iget helper

Christoph Hellwig
2008-08-12T18:46:54Z

> +struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
> + struct btrfs_root *root, int *is_new)
> +{
> + struct inode *inode;
> +
> + inode = btrfs_iget_locked(s, location->objectid, root);
> + if (!inode)
> + return ERR_PTR(-EACCES);
> +
> + if (inode->i_state & I_NEW) {
> + BTRFS_I(inode)->root = root;
> + memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
> + btrfs_read_locked_inode(inode);
> + unlock_new_inode(inode);
> + if (is_new)
> + *is_new = 1;
> + } else {
> + if (is_new)
> + *is_new = 0;
> + }
> +
> + return inode;

Please leave the unlock_new_inode to the caller and kill the is_new
parameter. Gives much nicer to read code, and generally making sure the
inode is 100% ready and correct before unlocking it is a good idea, too
so that e.g. no one can actually access an inode marked bad due to a
generation number mismatch before it's marked bad.

> +}
> +
> static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
> struct nameidata *nd)
> {
> @@ -1889,7 +1916,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
> struct btrfs_root *root = bi->root;
> struct btrfs_root *sub_root = root;
> struct btrfs_key location;
> - int ret, do_orphan = 0;
> + int ret, new, do_orphan = 0;
>
> if (dentry->d_name.len > BTRFS_NAME_LEN)
> return ERR_PTR(-ENAMETOOLONG);
> @@ -1907,23 +1934,15 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
> return ERR_PTR(ret);
> if (ret > 0)
> return ERR_PTR(-ENOENT);
> -
> - inode = btrfs_iget_locked(dir->i_sb, location.objectid,
> - sub_root);
> - if (!inode)
> - return ERR_PTR(-EACCES);
> - if (inode->i_state & I_NEW) {
> - /* the inode and parent dir are two different roots */
> - if (sub_root != root) {
> - igrab(inode);
> - sub_root->inode = inode;
> - do_orphan = 1;
> - }
> - BTRFS_I(inode)->root = sub_root;
> - memcpy(&BTRFS_I(inode)->location, &location,
> - sizeof(location));
> - btrfs_read_locked_inode(inode);
> - unlock_new_inode(inode);
> + inode = btrfs_iget(dir->i_sb, &location, sub_root, &new);
> + if (IS_ERR(inode))
> + return ERR_CAST(inode);
> +
> + /* the inode and parent dir are two different roots */
> + if (new && root != sub_root) {
> + igrab(inode);
> + sub_root->inode = inode;
> + do_orphan = 1;
> }
> }
>
> --
> 1.5.5.1
>
>
> --
> David Woodhouse Open Source Technology Centre
> David.Woodhouse@intel.com Intel Corporation
>
>
>
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