Patch "md/raid1: fix writebehind bio clone" has been added to the 4.12-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2017-08-01 01:16:46
This is a note to let you know that I've just added the patch titled
md/raid1: fix writebehind bio clone
to the 4.12-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:
md-raid1-fix-writebehind-bio-clone.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From 16d56e2fcc1fc15b981369653c3b41d7ff0b443d Mon Sep 17 00:00:00 2001
From: Shaohua Li <redacted> Date: Mon, 17 Jul 2017 14:33:48 -0700 Subject: md/raid1: fix writebehind bio clone From: Shaohua Li <redacted> commit 16d56e2fcc1fc15b981369653c3b41d7ff0b443d upstream. After bio is submitted, we should not clone it as its bi_iter might be invalid by driver. This is the case of behind_master_bio. In certain situration, we could dispatch behind_master_bio immediately for the first disk and then clone it for other disks. https://bugzilla.kernel.org/show_bug.cgi?id=196383 Reported-and-tested-by: Markus <redacted> Reviewed-by: Ming Lei <redacted> Fix: 841c1316c7da(md: raid1: improve write behind) Signed-off-by: Shaohua Li <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/md/raid1.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c@@ -491,10 +491,6 @@ static void raid1_end_write_request(stru } if (behind) { - /* we release behind master bio when all write are done */ - if (r1_bio->behind_master_bio == bio) - to_put = NULL; - if (test_bit(WriteMostly, &rdev->flags)) atomic_dec(&r1_bio->behind_remaining);
@@ -1087,7 +1083,7 @@ static void unfreeze_array(struct r1conf wake_up(&conf->wait_barrier); } -static struct bio *alloc_behind_master_bio(struct r1bio *r1_bio, +static void alloc_behind_master_bio(struct r1bio *r1_bio, struct bio *bio) { int size = bio->bi_iter.bi_size;
@@ -1097,11 +1093,13 @@ static struct bio *alloc_behind_master_b behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev); if (!behind_bio) - goto fail; + return; /* discard op, we don't support writezero/writesame yet */ - if (!bio_has_data(bio)) + if (!bio_has_data(bio)) { + behind_bio->bi_iter.bi_size = size; goto skip_copy; + } while (i < vcnt && size) { struct page *page;
@@ -1122,14 +1120,13 @@ skip_copy: r1_bio->behind_master_bio = behind_bio;; set_bit(R1BIO_BehindIO, &r1_bio->state); - return behind_bio; + return; free_pages: pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_iter.bi_size); bio_free_pages(behind_bio); -fail: - return behind_bio; + bio_put(behind_bio); } struct raid1_plug_cb {
@@ -1482,7 +1479,7 @@ static void raid1_write_request(struct m (atomic_read(&bitmap->behind_writes) < mddev->bitmap_info.max_write_behind) && !waitqueue_active(&bitmap->behind_wait)) { - mbio = alloc_behind_master_bio(r1_bio, bio); + alloc_behind_master_bio(r1_bio, bio); } bitmap_startwrite(bitmap, r1_bio->sector,
@@ -1492,14 +1489,11 @@ static void raid1_write_request(struct m first_clone = 0; } - if (!mbio) { - if (r1_bio->behind_master_bio) - mbio = bio_clone_fast(r1_bio->behind_master_bio, - GFP_NOIO, - mddev->bio_set); - else - mbio = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set); - } + if (r1_bio->behind_master_bio) + mbio = bio_clone_fast(r1_bio->behind_master_bio, + GFP_NOIO, mddev->bio_set); + else + mbio = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set); if (r1_bio->behind_master_bio) { if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
@@ -2367,8 +2361,6 @@ static int narrow_write_error(struct r1b wbio = bio_clone_fast(r1_bio->behind_master_bio, GFP_NOIO, mddev->bio_set); - /* We really need a _all clone */ - wbio->bi_iter = (struct bvec_iter){ 0 }; } else { wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO, mddev->bio_set);
Patches currently in stable-queue which might be from shli@fb.com are queue-4.12/md-remove-idx-from-struct-resync_pages.patch queue-4.12/md-raid1-fix-writebehind-bio-clone.patch queue-4.12/md-raid5-add-thread_group-worker-async_tx_issue_pending_all.patch