md/raid1: fix bio handling problems in process_checks()
commit 30bc9b53878a9921b02e3b5bc4283ac1c6de102a upstream.
Recent change to use bio_copy_data() in raid1 when repairing
an array is faulty.
The underlying may have changed the bio in various ways using
bio_advance and these need to be undone not just for the 'sbio' which
is being copied to, but also the 'pbio' (primary) which is being
copied from.
So perform the reset on all bios that were read from and do it early.
This also ensure that the sbio->bi_io_vec[j].bv_len passed to
memcmp is correct.
This fixes a crash during a 'check' of a RAID1 array. The crash was
introduced in 3.10 so this is suitable for 3.10-stable.
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6e17f81..6f48244 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1848,6 +1848,36 @@
int i;
int vcnt;
+ /* Fix variable parts of all bios */
+ vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ int j;
+ int size;
+ struct bio *b = r1_bio->bios[i];
+ if (b->bi_end_io != end_sync_read)
+ continue;
+ /* fixup the bio for reuse */
+ bio_reset(b);
+ b->bi_vcnt = vcnt;
+ b->bi_size = r1_bio->sectors << 9;
+ b->bi_sector = r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset;
+ b->bi_bdev = conf->mirrors[i].rdev->bdev;
+ b->bi_end_io = end_sync_read;
+ b->bi_private = r1_bio;
+
+ size = b->bi_size;
+ for (j = 0; j < vcnt ; j++) {
+ struct bio_vec *bi;
+ bi = &b->bi_io_vec[j];
+ bi->bv_offset = 0;
+ if (size > PAGE_SIZE)
+ bi->bv_len = PAGE_SIZE;
+ else
+ bi->bv_len = size;
+ size -= PAGE_SIZE;
+ }
+ }
for (primary = 0; primary < conf->raid_disks * 2; primary++)
if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
@@ -1856,12 +1886,10 @@
break;
}
r1_bio->read_disk = primary;
- vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
for (i = 0; i < conf->raid_disks * 2; i++) {
int j;
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];
- int size;
if (sbio->bi_end_io != end_sync_read)
continue;
@@ -1887,27 +1915,6 @@
rdev_dec_pending(conf->mirrors[i].rdev, mddev);
continue;
}
- /* fixup the bio for reuse */
- bio_reset(sbio);
- sbio->bi_vcnt = vcnt;
- sbio->bi_size = r1_bio->sectors << 9;
- sbio->bi_sector = r1_bio->sector +
- conf->mirrors[i].rdev->data_offset;
- sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
- sbio->bi_end_io = end_sync_read;
- sbio->bi_private = r1_bio;
-
- size = sbio->bi_size;
- for (j = 0; j < vcnt ; j++) {
- struct bio_vec *bi;
- bi = &sbio->bi_io_vec[j];
- bi->bv_offset = 0;
- if (size > PAGE_SIZE)
- bi->bv_len = PAGE_SIZE;
- else
- bi->bv_len = size;
- size -= PAGE_SIZE;
- }
bio_copy_data(sbio, pbio);
}