From 097426f689f179747f3cd6b4749eb2a6b605702d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 6 Jan 2006 00:20:37 -0800 Subject: [PATCH] md: fix possible problem in raid1/raid10 error overwriting The code to overwrite/reread for addressing read errors in raid1/raid10 currently assumes that the read will not alter the buffer which could be used to write to the next device. This is not a safe assumption to make. So we split the loops into a overwrite loop and a separate re-read loop, so that the writing is complete before reading is attempted. Cc: Paul Clements Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/raid10.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'drivers/md/raid10.c') diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index f23d52c5df9..9647ebb0983 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1421,6 +1421,7 @@ static void raid10d(mddev_t *mddev) } while (!success && sl != r10_bio->read_slot); if (success) { + int start = sl; /* write it back and re-read */ while (sl != r10_bio->read_slot) { int d; @@ -1434,14 +1435,27 @@ static void raid10d(mddev_t *mddev) if (sync_page_io(rdev->bdev, r10_bio->devs[sl].addr + sect + rdev->data_offset, - s<<9, conf->tmppage, WRITE) == 0 || - sync_page_io(rdev->bdev, + s<<9, conf->tmppage, WRITE) == 0) + /* Well, this device is dead */ + md_error(mddev, rdev); + } + } + sl = start; + while (sl != r10_bio->read_slot) { + int d; + if (sl==0) + sl = conf->copies; + sl--; + d = r10_bio->devs[sl].devnum; + rdev = conf->mirrors[d].rdev; + if (rdev && + test_bit(In_sync, &rdev->flags)) { + if (sync_page_io(rdev->bdev, r10_bio->devs[sl].addr + sect + rdev->data_offset, - s<<9, conf->tmppage, READ) == 0) { + s<<9, conf->tmppage, READ) == 0) /* Well, this device is dead */ md_error(mddev, rdev); - } } } } else { -- cgit v1.2.3