From patchwork Thu May 26 14:48:36 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 821062 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p4QEn3N0028834 for ; Thu, 26 May 2011 14:49:03 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754794Ab1EZOs6 (ORCPT ); Thu, 26 May 2011 10:48:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51678 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752693Ab1EZOs5 (ORCPT ); Thu, 26 May 2011 10:48:57 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p4QEmvHQ026589 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 26 May 2011 10:48:57 -0400 Received: from test1244.test.redhat.com (dhcp231-135.rdu.redhat.com [10.11.231.135]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p4QEmufl003369; Thu, 26 May 2011 10:48:57 -0400 From: Josef Bacik To: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 2/2] Btrfs: load the key from the dir item in readdir into a fake dentry Date: Thu, 26 May 2011 10:48:36 -0400 Message-Id: <1306421316-1504-2-git-send-email-josef@redhat.com> In-Reply-To: References: X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Thu, 26 May 2011 14:49:03 +0000 (UTC) In btrfs we have 2 indexes for inodes. One is for readdir, it's in this nice sequential order and works out brilliantly for readdir. However if you use ls, it usually stat's each file it gets from readdir. This is where the second index comes in, which is based on a hash of the name of the file. So then the lookup has to lookup this index, and then lookup the inode. The index lookup is going to be in random order (since its based on the name hash), which gives us less than stellar performance. Since we know the inode location from the readdir index, I create a dummy dentry and copy the location key into dentry->d_fsdata. Then on lookup if we have d_fsdata we use that location to lookup the inode, avoiding looking up the other directory index. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/inode.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 45 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6228a30..2a1a028 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4120,12 +4120,19 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) struct btrfs_root *sub_root = root; struct btrfs_key location; int index; - int ret; + int ret = 0; if (dentry->d_name.len > BTRFS_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); - ret = btrfs_inode_by_name(dir, dentry, &location); + if (unlikely(d_need_lookup(dentry))) { + memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key)); + kfree(dentry->d_fsdata); + dentry->d_fsdata = NULL; + d_clear_need_lookup(dentry); + } else { + ret = btrfs_inode_by_name(dir, dentry, &location); + } if (ret < 0) return ERR_PTR(ret); @@ -4180,6 +4187,12 @@ static int btrfs_dentry_delete(const struct dentry *dentry) return 0; } +static void btrfs_dentry_release(struct dentry *dentry) +{ + if (dentry->d_fsdata) + kfree(dentry->d_fsdata); +} + static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { @@ -4206,6 +4219,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent, struct btrfs_key key; struct btrfs_key found_key; struct btrfs_path *path; + struct qstr q; int ret; struct extent_buffer *leaf; int slot; @@ -4284,6 +4298,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent, while (di_cur < di_total) { struct btrfs_key location; + struct dentry *tmp; if (verify_dir_item(root, leaf, di)) break; @@ -4304,6 +4319,33 @@ static int btrfs_real_readdir(struct file *filp, void *dirent, d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; btrfs_dir_item_key_to_cpu(leaf, di, &location); + q.name = name_ptr; + q.len = name_len; + q.hash = full_name_hash(q.name, q.len); + tmp = d_lookup(filp->f_dentry, &q); + if (!tmp) { + struct btrfs_key *newkey; + + newkey = kzalloc(sizeof(struct btrfs_key), + GFP_NOFS); + if (!newkey) + goto no_dentry; + tmp = d_alloc(filp->f_dentry, &q); + if (!tmp) { + kfree(newkey); + dput(tmp); + goto no_dentry; + } + memcpy(newkey, &location, + sizeof(struct btrfs_key)); + tmp->d_fsdata = newkey; + tmp->d_flags |= DCACHE_NEED_LOOKUP; + d_rehash(tmp); + dput(tmp); + } else { + dput(tmp); + } +no_dentry: /* is this a reference to our own snapshot? If so * skip it */ @@ -7566,4 +7608,5 @@ static const struct inode_operations btrfs_symlink_inode_operations = { const struct dentry_operations btrfs_dentry_operations = { .d_delete = btrfs_dentry_delete, + .d_release = btrfs_dentry_release, };