Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756603Ab0LMCHU (ORCPT ); Sun, 12 Dec 2010 21:07:20 -0500 Received: from thunk.org ([69.25.196.29]:44636 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756189Ab0LMCHR (ORCPT ); Sun, 12 Dec 2010 21:07:17 -0500 Date: Sun, 12 Dec 2010 21:06:57 -0500 From: "Ted Ts'o" To: Jon Nelson Cc: Matt , Chris Mason , Andi Kleen , Mike Snitzer , Milan Broz , linux-btrfs , dm-devel , Linux Kernel , htd , htejun , linux-ext4 Subject: Re: hunt for 2.6.37 dm-crypt+ext4 corruption? (was: Re: dm-crypt barrier support is effective) Message-ID: <20101213020657.GB4513@thunk.org> Mail-Followup-To: Ted Ts'o , Jon Nelson , Matt , Chris Mason , Andi Kleen , Mike Snitzer , Milan Broz , linux-btrfs , dm-devel , Linux Kernel , htd , htejun , linux-ext4 References: <20101210023852.GB3059@thunk.org>

<20101212023415.GG3059@thunk.org> <20101212124354.GA4513@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5231 Lines: 133 On Sun, Dec 12, 2010 at 07:11:28AM -0600, Jon Nelson wrote: > I'm glad you've been able to reproduce the problem! If you should need > any further assistance, please do not hesitate to ask. This patch seems to fix the problem for me. (Unless the partition is mounted with mblk_io_submit.) Could you confirm that it fixes it for you as well? Thanks! - Ted commit a8649d85bd0ab3be6014918bd9eae319a0ffc691 Author: Theodore Ts'o Date: Sun Dec 12 20:57:19 2010 -0500 ext4: Turn off multiple page-io submission by default Jon Nelson has found a test case which causes postgresql to fail with the error: psql:t.sql:4: ERROR: invalid page header in block 38269 of relation base/16384/16581 Under memory pressure, it looks like part of a file can end up getting replaced by zero's. Until we can figure out the cause, we'll roll back the change and use block_write_full_page() instead of ext4_bio_write_page(). The new, more efficient writing function can be used via the mount option mblk_io_submit, so we can test and fix the new page I/O code. To reproduce the problem, install postgres 8.4 or 9.0, and pin enough memory such that the system just at the end of triggering writeback before running the following sql script: begin; create temporary table foo as select x as a, ARRAY[x] as b FROM generate_series(1, 10000000 ) AS x; create index foo_a_idx on foo (a); create index foo_b_idx on foo USING GIN (b); rollback; If the temporary table is created on a hard drive partition which is encrypted using dm_crypt, then under memory pressure, approximately 30-40% of the time, pgsql will issue the above failure. This patch should fix this problem, and the problem will come back if the file system is mounted with the mblk_io_submit mount option. Reported-by: Jon Nelson Signed-off-by: "Theodore Ts'o" diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 6a5edea..6eb598b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -910,6 +910,7 @@ struct ext4_inode_info { #define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */ #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */ #define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */ +#define EXT4_MOUNT_MBLK_IO_SUBMIT 0x4000000 #define EXT4_MOUNT_DELALLOC 0x8000000 /* Delalloc support */ #define EXT4_MOUNT_DATA_ERR_ABORT 0x10000000 /* Abort on file data write */ #define EXT4_MOUNT_BLOCK_VALIDITY 0x20000000 /* Block validity checking */ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index bdbe699..e659597 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2125,9 +2125,12 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd, */ if (unlikely(journal_data && PageChecked(page))) err = __ext4_journalled_writepage(page, len); - else + else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT)) err = ext4_bio_write_page(&io_submit, page, len, mpd->wbc); + else + err = block_write_full_page(page, + noalloc_get_block_write, mpd->wbc); if (!err) mpd->pages_written++; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e32195d..fb15c9c 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1026,6 +1026,8 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs) !(def_mount_opts & EXT4_DEFM_NODELALLOC)) seq_puts(seq, ",nodelalloc"); + if (test_opt(sb, MBLK_IO_SUBMIT)) + seq_puts(seq, ",mblk_io_submit"); if (sbi->s_stripe) seq_printf(seq, ",stripe=%lu", sbi->s_stripe); /* @@ -1239,8 +1241,8 @@ enum { Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota, Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version, - Opt_stripe, Opt_delalloc, Opt_nodelalloc, - Opt_block_validity, Opt_noblock_validity, + Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit, + Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity, Opt_inode_readahead_blks, Opt_journal_ioprio, Opt_dioread_nolock, Opt_dioread_lock, Opt_discard, Opt_nodiscard, @@ -1304,6 +1306,8 @@ static const match_table_t tokens = { {Opt_resize, "resize"}, {Opt_delalloc, "delalloc"}, {Opt_nodelalloc, "nodelalloc"}, + {Opt_mblk_io_submit, "mblk_io_submit"}, + {Opt_nomblk_io_submit, "nomblk_io_submit"}, {Opt_block_validity, "block_validity"}, {Opt_noblock_validity, "noblock_validity"}, {Opt_inode_readahead_blks, "inode_readahead_blks=%u"}, @@ -1725,6 +1729,12 @@ set_qf_format: case Opt_nodelalloc: clear_opt(sbi->s_mount_opt, DELALLOC); break; + case Opt_mblk_io_submit: + set_opt(sbi->s_mount_opt, MBLK_IO_SUBMIT); + break; + case Opt_nomblk_io_submit: + clear_opt(sbi->s_mount_opt, MBLK_IO_SUBMIT); + break; case Opt_stripe: if (match_int(&args[0], &option)) return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/