[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 <paul.clements@steeleye.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6e0f59e..39c10a6 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1253,6 +1253,7 @@
} while (!success && d != r1_bio->read_disk);
if (success) {
+ int start = d;
/* write it back and re-read */
set_bit(R1BIO_Uptodate, &r1_bio->state);
while (d != r1_bio->read_disk) {
@@ -1266,14 +1267,23 @@
sect + rdev->data_offset,
s<<9,
bio->bi_io_vec[idx].bv_page,
- WRITE) == 0 ||
- sync_page_io(rdev->bdev,
+ WRITE) == 0)
+ md_error(mddev, rdev);
+ }
+ d = start;
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev->bdev,
sect + rdev->data_offset,
s<<9,
bio->bi_io_vec[idx].bv_page,
- READ) == 0) {
+ READ) == 0)
md_error(mddev, rdev);
- }
}
} else {
char b[BDEVNAME_SIZE];
@@ -1445,6 +1455,7 @@
if (success) {
/* write it back and re-read */
+ int start = d;
while (d != r1_bio->read_disk) {
if (d==0)
d = conf->raid_disks;
@@ -1454,13 +1465,24 @@
test_bit(In_sync, &rdev->flags)) {
if (sync_page_io(rdev->bdev,
sect + rdev->data_offset,
- s<<9, conf->tmppage, WRITE) == 0 ||
- sync_page_io(rdev->bdev,
- sect + rdev->data_offset,
- s<<9, conf->tmppage, READ) == 0) {
+ s<<9, conf->tmppage, WRITE) == 0)
/* Well, this device is dead */
md_error(mddev, rdev);
- }
+ }
+ }
+ d = start;
+ while (d != r1_bio->read_disk) {
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev->bdev,
+ sect + rdev->data_offset,
+ s<<9, conf->tmppage, READ) == 0)
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
}
}
} else {