From patchwork Fri Jul 1 20:58:51 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arne Jansen X-Patchwork-Id: 937982 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p61Kx3BM000898 for ; Fri, 1 Jul 2011 20:59:03 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757168Ab1GAU64 (ORCPT ); Fri, 1 Jul 2011 16:58:56 -0400 Received: from ysabell.rzone.de ([81.169.144.237]:59655 "EHLO ysabell.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870Ab1GAU6z (ORCPT ); Fri, 1 Jul 2011 16:58:55 -0400 Received: from gargravarr.store (gargravarr.store [192.168.42.236]) by ysabell.rzone.de (Postfix) with ESMTP id AA3D83A; Fri, 1 Jul 2011 22:58:53 +0200 (MEST) Received: by gargravarr.store (Postfix, from userid 32466) id A190B44E0B; Fri, 1 Jul 2011 22:58:53 +0200 (CEST) From: Arne Jansen To: chris.mason@oracle.com, linux-btrfs@vger.kernel.org Subject: [PATCH v5 5/7] btrfs: hooks for readahead Date: Fri, 1 Jul 2011 22:58:51 +0200 Message-Id: X-Mailer: git-send-email 1.7.3.4 In-Reply-To: References: In-Reply-To: References: 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]); Fri, 01 Jul 2011 20:59:03 +0000 (UTC) This adds the hooks needed for readahead. In the readpage_end_io_hook, the extent state is checked for the EXTENT_READAHEAD flag. Only in this case the readahead hook is called, to keep the impact on non-ra as low as possible. Additionally, a hook for a failed IO is added, otherwise readahead would wait indefinitely for the extent to finish. Changes for v2: - eliminate race condition Signed-off-by: Arne Jansen --- fs/btrfs/disk-io.c | 37 +++++++++++++++++++++++++++++++++++++ fs/btrfs/extent_io.c | 2 +- 2 files changed, 38 insertions(+), 1 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 7fbdfa1..465ebbf 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -575,11 +575,47 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, end = min_t(u64, eb->len, PAGE_CACHE_SIZE); end = eb->start + end - 1; err: + if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) { + clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags); + btree_readahead_hook(root, eb, eb->start, ret); + } + free_extent_buffer(eb); out: return ret; } +static int btree_io_failed_hook(struct bio *failed_bio, + struct page *page, u64 start, u64 end, + struct extent_state *state) +{ + struct extent_io_tree *tree; + unsigned long len; + struct extent_buffer *eb; + struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; + + tree = &BTRFS_I(page->mapping->host)->io_tree; + if (page->private == EXTENT_PAGE_PRIVATE) + goto out; + if (!page->private) + goto out; + + len = page->private >> 2; + WARN_ON(len == 0); + + eb = alloc_extent_buffer(tree, start, len, page); + if (eb == NULL) + goto out; + + if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) { + clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags); + btree_readahead_hook(root, eb, eb->start, -EIO); + } + +out: + return -EIO; /* we fixed nothing */ +} + static void end_workqueue_bio(struct bio *bio, int err) { struct end_io_wq *end_io_wq = bio->bi_private; @@ -3134,6 +3170,7 @@ static int btrfs_cleanup_transaction(struct btrfs_root *root) static struct extent_io_ops btree_extent_io_ops = { .write_cache_pages_lock_hook = btree_lock_page_hook, .readpage_end_io_hook = btree_readpage_end_io_hook, + .readpage_io_failed_hook = btree_io_failed_hook, .submit_bio_hook = btree_submit_bio_hook, /* note we're sharing with inode.c for the merge bio hook */ .merge_bio_hook = btrfs_merge_bio_hook, diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index f48b072..877e24f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1774,7 +1774,7 @@ static void end_bio_extent_readpage(struct bio *bio, int err) if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) { ret = tree->ops->readpage_io_failed_hook(bio, page, - start, end, NULL); + start, end, state); if (ret == 0) { uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);