From: NeilBrown Date: Fri, 23 May 2008 20:04:35 +0000 (-0700) Subject: md: raid1: Fix restoration of bio between failed read and write. X-Git-Tag: v2.6.26-rc4~39 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=698b18c1e8bddf39cbf1ba50792b0fe302dbe6d6;p=linux-2.6 md: raid1: Fix restoration of bio between failed read and write. When performing a "recovery" or "check" pass on a RAID1 array, we read from each device and possible, if there is a difference or a read error, write back to some devices. We use the same 'bio' for both read and write, resetting various fields between the two operations. We forgot to reset bv_offset and bv_len however. These are often left unchanged, but in the case where there is an IO error one or two sectors into a page, they are changed. This results in correctable errors not being corrected properly. It does not result in any data corruption. Cc: "Fairbanks, David" Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 21629ae466..d0f4021bbc 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1284,6 +1284,7 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) rdev_dec_pending(conf->mirrors[i].rdev, mddev); } else { /* fixup the bio for reuse */ + int size; sbio->bi_vcnt = vcnt; sbio->bi_size = r1_bio->sectors << 9; sbio->bi_idx = 0; @@ -1297,10 +1298,20 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) sbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; sbio->bi_bdev = conf->mirrors[i].rdev->bdev; - for (j = 0; j < vcnt ; j++) - memcpy(page_address(sbio->bi_io_vec[j].bv_page), + 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; + memcpy(page_address(bi->bv_page), page_address(pbio->bi_io_vec[j].bv_page), PAGE_SIZE); + } } }