[PATCH] md - Use sector rather than block numbers when splitting raid0 requests.

When raid0 needs to split a request, it uses 'block' (1K) addresses
rather than sector (512b) addresses, which causes problems if the sector
address is odd.  This patch fixes the problem.

Thanks to Andy Polyakov <appro@fy.chalmers.se>

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 78159e30fdea8a02834e675c47898701a7686b75..d076ef976308cbf8ffcc0cd266ed58c81c624699 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -332,7 +332,7 @@ static int raid0_stop (mddev_t *mddev)
 static int raid0_make_request (request_queue_t *q, struct bio *bio)
 {
        mddev_t *mddev = q->queuedata;
-       unsigned int sect_in_chunk, chunksize_bits,  chunk_size;
+       unsigned int sect_in_chunk, chunksize_bits,  chunk_size, chunk_sects;
        raid0_conf_t *conf = mddev_to_conf(mddev);
        struct strip_zone *zone;
        mdk_rdev_t *tmp_dev;
@@ -340,11 +340,12 @@ static int raid0_make_request (request_queue_t *q, struct bio *bio)
        sector_t block, rsect;
 
        chunk_size = mddev->chunk_size >> 10;
+       chunk_sects = mddev->chunk_size >> 9;
        chunksize_bits = ffz(~chunk_size);
        block = bio->bi_sector >> 1;
        
 
-       if (unlikely(chunk_size < (block & (chunk_size - 1)) + (bio->bi_size >> 10))) {
+       if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) {
                struct bio_pair *bp;
                /* Sanity check -- queue functions should prevent this happening */
                if (bio->bi_vcnt != 1 ||
@@ -353,7 +354,7 @@ static int raid0_make_request (request_queue_t *q, struct bio *bio)
                /* This is a one page bio that upper layers
                 * refuse to split for us, so we need to split it.
                 */
-               bp = bio_split(bio, bio_split_pool, (chunk_size - (block & (chunk_size - 1)))<<1 );
+               bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
                if (raid0_make_request(q, &bp->bio1))
                        generic_make_request(&bp->bio1);
                if (raid0_make_request(q, &bp->bio2))