[patch 08/26] md: Fix bug in error handling during raid1 repair.

Greg KH
2007-07-31T04:33:07Z

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-stable review patch. If anyone has any objections, please let us know.

------------------

From: Mike Accetta <maccetta@laurelnetworks.com>

If raid1/repair (which reads all block and fixes any differences
it finds) hits a read error, it doesn't reset the bio for writing
before writing correct data back, so the read error isn't fixed,
and the device probably gets a zero-length write which it might
complain about.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

drivers/md/raid1.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff .prev/drivers/md/raid1.c ./drivers/md/raid1.c
--- linux-2.6.21.6.orig/drivers/md/raid1.c
+++ linux-2.6.21.6/drivers/md/raid1.c
@@ -1240,17 +1240,24 @@ static void sync_request_write(mddev_t *
}
r1_bio->read_disk = primary;
for (i=0; i<mddev->raid_disks; i++)
- if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
- test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
+ if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
int j;
int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];
- for (j = vcnt; j-- ; )
- if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
- page_address(sbio->bi_io_vec[j].bv_page),
- PAGE_SIZE))
- break;
+
+ if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
+ for (j = vcnt; j-- ; ) {
+ struct page *p, *s;
+ p = pbio->bi_io_vec[j].bv_page;
+ s = sbio->bi_io_vec[j].bv_page;
+ if (memcmp(page_address(p),
+ page_address(s),
+ PAGE_SIZE))
+ break;
+ }
+ } else
+ j = 0;
if (j >= 0)
mddev->resync_mismatches += r1_bio->sectors;
if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {

--