| Message ID | 1423577372-25061-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 222aa7521877..68a03d7f25ee 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3204,6 +3204,11 @@ static void handle_stripe_dirtying(struct r5conf *conf, (unsigned long long)sh->sector, rcw, qread, test_bit(STRIPE_DELAYED, &sh->state)); } + + if (rcw > disks && rmw > disks && + !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) + set_bit(STRIPE_DELAYED, &sh->state); + /* now if nothing is locked, and if we have enough data, * we can start a write request */
This is a note to let you know that I have just added a patch titled md/raid5: fix another livelock caused by non-aligned writes. to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt7. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 9aae570c5453e0d7fd7fafd07f9cabb5bec9386a Mon Sep 17 00:00:00 2001 From: NeilBrown <neilb@suse.de> Date: Mon, 2 Feb 2015 10:44:29 +1100 Subject: md/raid5: fix another livelock caused by non-aligned writes. commit b1b02fe97f75b12ab34b2303bfd4e3526d903a58 upstream. If a non-page-aligned write is destined for a device which is missing/faulty, we can deadlock. As the target device is missing, a read-modify-write cycle is not possible. As the write is not for a full-page, a recontruct-write cycle is not possible. This should be handled by logic in fetch_block() which notices there is a non-R5_OVERWRITE write to a missing device, and so loads all blocks. However since commit 67f455486d2ea2, that code requires STRIPE_PREREAD_ACTIVE before it will active, and those circumstances never set STRIPE_PREREAD_ACTIVE. So: in handle_stripe_dirtying, if neither rmw or rcw was possible, set STRIPE_DELAYED, which will cause STRIPE_PREREAD_ACTIVE be set after a suitable delay. Fixes: 67f455486d2ea20b2d94d6adf5b9b783d079e321 Reported-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/md/raid5.c | 5 +++++ 1 file changed, 5 insertions(+) -- 2.1.4