From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59952 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751020AbcJEPpr (ORCPT ); Wed, 5 Oct 2016 11:45:47 -0400 Subject: Patch "dm log writes: fix bug with too large bios" has been added to the 4.7-stable tree To: mpatocka@redhat.com, gregkh@linuxfoundation.org, jbacik@fb.com, snitzer@redhat.com Cc: , From: Date: Wed, 05 Oct 2016 17:39:45 +0200 Message-ID: <147568198525273@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dm log writes: fix bug with too large bios to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-log-writes-fix-bug-with-too-large-bios.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 7efb367320f56fc4d549875b6f3a6940018ef2e5 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 30 Aug 2016 16:20:55 -0400 Subject: dm log writes: fix bug with too large bios From: Mikulas Patocka commit 7efb367320f56fc4d549875b6f3a6940018ef2e5 upstream. bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector entries. However, the incoming bio may have more vector entries if it was allocated by other means. For example, bcache submits bios with more than BIO_MAX_PAGES entries. This results in bio_alloc() failure. To avoid the failure, change the code so that it allocates bio with at most BIO_MAX_PAGES entries. If the incoming bio has more entries, bio_add_page() will fail and a new bio will be allocated - the code that handles bio_add_page() failure already exists in the dm-log-writes target. Signed-off-by: Mikulas Patocka Reviewed-by: Josef Bacik Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-log-writes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -259,7 +259,7 @@ static int log_one_block(struct log_writ sector++; atomic_inc(&lc->io_blocks); - bio = bio_alloc(GFP_KERNEL, block->vec_cnt); + bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; @@ -280,7 +280,7 @@ static int log_one_block(struct log_writ if (ret != block->vecs[i].bv_len) { atomic_inc(&lc->io_blocks); submit_bio(WRITE, bio); - bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i); + bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES)); if (!bio) { DMERR("Couldn't alloc log bio"); goto error; Patches currently in stable-queue which might be from mpatocka@redhat.com are queue-4.7/dm-log-writes-fix-bug-with-too-large-bios.patch