From patchwork Tue Apr 16 22:15:34 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 2451291 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 6278F3FD8C for ; Tue, 16 Apr 2013 22:14:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965492Ab3DPWO0 (ORCPT ); Tue, 16 Apr 2013 18:14:26 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54165 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965485Ab3DPWOZ (ORCPT ); Tue, 16 Apr 2013 18:14:25 -0400 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 08043A5539; Wed, 17 Apr 2013 00:14:24 +0200 (CEST) From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: Josef Bacik , chris.mason@fusionio.com, Mark Fasheh Subject: [PATCH 3/4] btrfs: Introduce extent_read_full_page_nolock() Date: Tue, 16 Apr 2013 15:15:34 -0700 Message-Id: <1366150535-18750-4-git-send-email-mfasheh@suse.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1366150535-18750-1-git-send-email-mfasheh@suse.de> References: <1366150535-18750-1-git-send-email-mfasheh@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org We want this for btrfs_extent_same. Basically readpage and friends do their own extent locking but for the purposes of dedupe, we want to have both files locked down across a set of readpage operations (so that we can compare data). Introduce this variant and a flag which can be set for extent_read_full_page() to indicate that we are already locked. Signed-off-by: Mark Fasheh --- fs/btrfs/extent_io.c | 44 ++++++++++++++++++++++++++++++++------------ fs/btrfs/extent_io.h | 2 ++ 2 files changed, 34 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 1b319df..9256503 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2592,7 +2592,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, struct page *page, get_extent_t *get_extent, struct bio **bio, int mirror_num, - unsigned long *bio_flags) + unsigned long *bio_flags, int parent_locked) { struct inode *inode = page->mapping->host; u64 start = (u64)page->index << PAGE_CACHE_SHIFT; @@ -2625,7 +2625,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, } end = page_end; - while (1) { + while (1 && !parent_locked) { lock_extent(tree, start, end); ordered = btrfs_lookup_ordered_extent(inode, start); if (!ordered) @@ -2659,15 +2659,18 @@ static int __extent_read_full_page(struct extent_io_tree *tree, kunmap_atomic(userpage); set_extent_uptodate(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); - unlock_extent_cached(tree, cur, cur + iosize - 1, - &cached, GFP_NOFS); + if (!parent_locked) + unlock_extent_cached(tree, cur, + cur + iosize - 1, + &cached, GFP_NOFS); break; } em = get_extent(inode, page, pg_offset, cur, end - cur + 1, 0); if (IS_ERR_OR_NULL(em)) { SetPageError(page); - unlock_extent(tree, cur, end); + if (!parent_locked) + unlock_extent(tree, cur, end); break; } extent_offset = cur - em->start; @@ -2719,7 +2722,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree, if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1, NULL)) { check_page_uptodate(tree, page); - unlock_extent(tree, cur, cur + iosize - 1); + if (!parent_locked) + unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; pg_offset += iosize; continue; @@ -2729,7 +2733,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree, */ if (block_start == EXTENT_MAP_INLINE) { SetPageError(page); - unlock_extent(tree, cur, cur + iosize - 1); + if (!parent_locked) + unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; pg_offset += iosize; continue; @@ -2756,7 +2761,8 @@ static int __extent_read_full_page(struct extent_io_tree *tree, } if (ret) { SetPageError(page); - unlock_extent(tree, cur, cur + iosize - 1); + if (!parent_locked) + unlock_extent(tree, cur, cur + iosize - 1); } cur = cur + iosize; pg_offset += iosize; @@ -2778,7 +2784,21 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page, int ret; ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, - &bio_flags); + &bio_flags, 0); + if (bio) + ret = submit_one_bio(READ, bio, mirror_num, bio_flags); + return ret; +} + +int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page, + get_extent_t *get_extent, int mirror_num) +{ + struct bio *bio = NULL; + unsigned long bio_flags = 0; + int ret; + + ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, + &bio_flags, 1); if (bio) ret = submit_one_bio(READ, bio, mirror_num, bio_flags); return ret; @@ -3648,14 +3668,14 @@ int extent_readpages(struct extent_io_tree *tree, continue; for (i = 0; i < nr; i++) { __extent_read_full_page(tree, pagepool[i], get_extent, - &bio, 0, &bio_flags); + &bio, 0, &bio_flags, 0); page_cache_release(pagepool[i]); } nr = 0; } for (i = 0; i < nr; i++) { __extent_read_full_page(tree, pagepool[i], get_extent, - &bio, 0, &bio_flags); + &bio, 0, &bio_flags, 0); page_cache_release(pagepool[i]); } @@ -4620,7 +4640,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, ClearPageError(page); err = __extent_read_full_page(tree, page, get_extent, &bio, - mirror_num, &bio_flags); + mirror_num, &bio_flags, 0); if (err) ret = err; } else { diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 2eacfab..71752fc 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -202,6 +202,8 @@ int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end, int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end); int extent_read_full_page(struct extent_io_tree *tree, struct page *page, get_extent_t *get_extent, int mirror_num); +int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page, + get_extent_t *get_extent, int mirror_num); int __init extent_io_init(void); void extent_io_exit(void);