From patchwork Mon Nov 16 07:08:41 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Rajendra X-Patchwork-Id: 7621241 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6E37CBF90C for ; Mon, 16 Nov 2015 07:09:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2425C2054A for ; Mon, 16 Nov 2015 07:09:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B75E205B5 for ; Mon, 16 Nov 2015 07:09:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751929AbbKPHJK (ORCPT ); Mon, 16 Nov 2015 02:09:10 -0500 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:52301 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266AbbKPHJG (ORCPT ); Mon, 16 Nov 2015 02:09:06 -0500 Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 16 Nov 2015 12:39:02 +0530 X-Helo: d28dlp03.in.ibm.com X-MailFrom: chandan@linux.vnet.ibm.com X-RcptTo: linux-btrfs@vger.kernel.org Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 3F7E51258098 for ; Mon, 16 Nov 2015 12:39:09 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tAG7908c45154388 for ; Mon, 16 Nov 2015 12:39:00 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tAG78v4g027424 for ; Mon, 16 Nov 2015 12:38:58 +0530 Received: from localhost.in.ibm.com ([9.124.35.170]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id tAG78tLh027210; Mon, 16 Nov 2015 12:38:57 +0530 From: Chandan Rajendra To: linux-btrfs@vger.kernel.org Cc: Chandan Rajendra , jbacik@fb.com, clm@fb.com, bo.li.liu@oracle.com, dsterba@suse.cz, chandan@mykolab.com Subject: [RFC PATCH V12 14/14] Btrfs: subpagesize-blocksize: extent_clear_unlock_delalloc: Prevent page from being unlocked more than once Date: Mon, 16 Nov 2015 12:38:41 +0530 Message-Id: <1447657721-10025-15-git-send-email-chandan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1447657721-10025-1-git-send-email-chandan@linux.vnet.ibm.com> References: <1447657721-10025-1-git-send-email-chandan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15111607-4790-0000-0000-00000B9086B0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP extent_clear_unlock_delalloc() can unlock a page more than once as shown below (assume 4k as the block size and 64k as the page size). cow_file_range create 4k ordered extent corresponding to page offsets 0 - 4095 extent_clear_unlock_delalloc corresponding to page offsets 0 - 4095 unlock page create 4k ordered extent corresponding to page offsets 4096 - 8191 extent_clear_unlock_delalloc corresponding to page offsets 4096 - 8191 unlock page To prevent such a scenario this commit passes "delalloc end" to extent_clear_unlock_delalloc() to help decide whether the page can be unlocked or not. NOTE: Since extent_clear_unlock_delalloc() is used by compression code as well, the commit passes ordered extent "end" as the value for the argument corresponding to "delalloc end" for invocations made from compression code path. This will be fixed by a future commit that gets compression to work in subpagesize-blocksize scenario. Signed-off-by: Chandan Rajendra --- fs/btrfs/extent_io.c | 15 ++++++---- fs/btrfs/extent_io.h | 5 ++-- fs/btrfs/inode.c | 84 ++++++++++++++++++++++++++++++---------------------- 3 files changed, 60 insertions(+), 44 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 052c5c0..a6ab44c 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1914,9 +1914,8 @@ out_failed: } int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, - struct page *locked_page, - unsigned clear_bits, - unsigned long page_ops) + u64 delalloc_end, struct page *locked_page, + unsigned clear_bits, unsigned long page_ops) { struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; int ret; @@ -1924,6 +1923,7 @@ int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, unsigned long index = start >> PAGE_CACHE_SHIFT; unsigned long end_index = end >> PAGE_CACHE_SHIFT; unsigned long nr_pages = end_index - index + 1; + u64 page_end; int i; clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS); @@ -1960,8 +1960,13 @@ int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, if ((page_ops & PAGE_END_WRITEBACK) && !PagePrivate2(pages[i])) end_page_writeback(pages[i]); - if (page_ops & PAGE_UNLOCK) - unlock_page(pages[i]); + if (page_ops & PAGE_UNLOCK) { + page_end = page_offset(pages[i]) + + PAGE_CACHE_SIZE - 1; + if ((page_end <= end) + || (end == delalloc_end)) + unlock_page(pages[i]); + } page_cache_release(pages[i]); } nr_pages -= ret; diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index b9407b2..395b16f 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -386,9 +386,8 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset, int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end); int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end); int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, - struct page *locked_page, - unsigned bits_to_clear, - unsigned long page_ops); + u64 delalloc_end, struct page *locked_page, + unsigned bits_to_clear, unsigned long page_ops); struct bio * btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, gfp_t gfp_flags); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index bd96bac..7ea078f 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -98,9 +98,10 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr); static int btrfs_truncate(struct inode *inode); static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); static noinline int cow_file_range(struct inode *inode, - struct page *locked_page, - u64 start, u64 end, int *page_started, - unsigned long *nr_written, int unlock); + struct page *locked_page, + u64 start, u64 end, u64 delalloc_end, + int *page_started, unsigned long *nr_written, + int unlock); static struct extent_map *create_pinned_em(struct inode *inode, u64 start, u64 len, u64 orig_start, u64 block_start, u64 block_len, @@ -555,12 +556,13 @@ cont: * we don't need to create any more async work items. * Unlock and free up our temp pages. */ - extent_clear_unlock_delalloc(inode, start, end, NULL, - clear_flags, PAGE_UNLOCK | - PAGE_CLEAR_DIRTY | - PAGE_SET_WRITEBACK | - page_error_op | - PAGE_END_WRITEBACK); + extent_clear_unlock_delalloc(inode, start, end, end, + NULL, clear_flags, + PAGE_UNLOCK + | PAGE_CLEAR_DIRTY + | PAGE_SET_WRITEBACK + | page_error_op + | PAGE_END_WRITEBACK); goto free_pages_out; } } @@ -709,6 +711,8 @@ retry: async_extent->start, async_extent->start + async_extent->ram_size - 1, + async_extent->start + + async_extent->ram_size - 1, &page_started, &nr_written, 0); /* JDM XXX */ @@ -828,6 +832,8 @@ retry: extent_clear_unlock_delalloc(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, + async_extent->start + + async_extent->ram_size - 1, NULL, EXTENT_LOCKED | EXTENT_DELALLOC, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK); @@ -847,9 +853,10 @@ retry: tree->ops->writepage_end_io_hook(p, start, end, NULL, 0); p->mapping = NULL; - extent_clear_unlock_delalloc(inode, start, end, NULL, 0, - PAGE_END_WRITEBACK | - PAGE_SET_ERROR); + extent_clear_unlock_delalloc(inode, start, end, end, + NULL, 0, + PAGE_END_WRITEBACK | + PAGE_SET_ERROR); free_async_extent_pages(async_extent); } alloc_hint = ins.objectid + ins.offset; @@ -863,6 +870,8 @@ out_free: extent_clear_unlock_delalloc(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, + async_extent->start + + async_extent->ram_size - 1, NULL, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | @@ -919,10 +928,10 @@ static u64 get_extent_allocation_hint(struct inode *inode, u64 start, * IO when we return. */ static noinline int cow_file_range(struct inode *inode, - struct page *locked_page, - u64 start, u64 end, int *page_started, - unsigned long *nr_written, - int unlock) + struct page *locked_page, + u64 start, u64 end, u64 delalloc_end, + int *page_started, unsigned long *nr_written, + int unlock) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 alloc_hint = 0; @@ -958,7 +967,8 @@ static noinline int cow_file_range(struct inode *inode, ret = cow_file_range_inline(root, inode, start, end, 0, 0, NULL); if (ret == 0) { - extent_clear_unlock_delalloc(inode, start, end, NULL, + extent_clear_unlock_delalloc(inode, start, end, + delalloc_end, NULL, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | @@ -1048,9 +1058,9 @@ static noinline int cow_file_range(struct inode *inode, page_ops = unlock ? PAGE_UNLOCK : 0; page_ops |= PAGE_SET_PRIVATE2; extent_ops = EXTENT_LOCKED | EXTENT_DELALLOC; - extent_clear_unlock_delalloc(inode, start, - start + ram_size - 1, locked_page, - extent_ops, page_ops); + extent_clear_unlock_delalloc(inode, start, start + ram_size - 1, + delalloc_end, locked_page, extent_ops, + page_ops); disk_num_bytes -= cur_alloc_size; num_bytes -= cur_alloc_size; alloc_hint = ins.objectid + ins.offset; @@ -1081,8 +1091,8 @@ out_unlock: extent_ops = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG; - extent_clear_unlock_delalloc(inode, start, end, locked_page, - extent_ops, page_ops); + extent_clear_unlock_delalloc(inode, start, end, delalloc_end, + locked_page, extent_ops, page_ops); goto out; } @@ -1229,9 +1239,9 @@ static noinline int csum_exist_in_range(struct btrfs_root *root, * blocks on disk */ static noinline int run_delalloc_nocow(struct inode *inode, - struct page *locked_page, - u64 start, u64 end, int *page_started, int force, - unsigned long *nr_written) + struct page *locked_page, + u64 start, u64 end, int *page_started, + int force, unsigned long *nr_written) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; @@ -1257,7 +1267,8 @@ static noinline int run_delalloc_nocow(struct inode *inode, path = btrfs_alloc_path(); if (!path) { - extent_clear_unlock_delalloc(inode, start, end, locked_page, + extent_clear_unlock_delalloc(inode, start, end, end, + locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, PAGE_UNLOCK | @@ -1275,7 +1286,8 @@ static noinline int run_delalloc_nocow(struct inode *inode, trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { - extent_clear_unlock_delalloc(inode, start, end, locked_page, + extent_clear_unlock_delalloc(inode, start, end, end, + locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, PAGE_UNLOCK | @@ -1410,8 +1422,8 @@ out_check: btrfs_release_path(path); if (cow_start != (u64)-1) { ret = cow_file_range(inode, locked_page, - cow_start, found_key.offset - 1, - page_started, nr_written, 1); + cow_start, found_key.offset - 1, end, + page_started, nr_written, 1); if (ret) { if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); @@ -1471,10 +1483,10 @@ out_check: } extent_clear_unlock_delalloc(inode, cur_offset, - cur_offset + num_bytes - 1, - locked_page, EXTENT_LOCKED | - EXTENT_DELALLOC, PAGE_UNLOCK | - PAGE_SET_PRIVATE2); + cur_offset + num_bytes - 1, end, + locked_page, EXTENT_LOCKED | + EXTENT_DELALLOC, PAGE_UNLOCK | + PAGE_SET_PRIVATE2); if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); cur_offset = extent_end; @@ -1489,7 +1501,7 @@ out_check: } if (cow_start != (u64)-1) { - ret = cow_file_range(inode, locked_page, cow_start, end, + ret = cow_file_range(inode, locked_page, cow_start, end, end, page_started, nr_written, 1); if (ret) goto error; @@ -1501,7 +1513,7 @@ error: ret = err; if (ret && cur_offset < end) - extent_clear_unlock_delalloc(inode, cur_offset, end, + extent_clear_unlock_delalloc(inode, cur_offset, end, end, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | @@ -1549,7 +1561,7 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page, ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 0, nr_written); } else if (!inode_need_compress(inode)) { - ret = cow_file_range(inode, locked_page, start, end, + ret = cow_file_range(inode, locked_page, start, end, end, page_started, nr_written, 1); } else { set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,