X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fmd%2Fraid5.c;h=269b7771a30b79e2d1c01b4cca0fd43593ec27c1;hb=f679623f50545bc0577caf2d0f8675b61162f059;hp=e14f4578072006e3b464668d3c8500187df76453;hpb=12e36b2f41b6cbc67386fcb9c59c32a3e2033905;p=linux-2.6

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e14f457807..269b7771a3 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -348,7 +348,7 @@ static int grow_one_stripe(raid5_conf_t *conf)
 
 static int grow_stripes(raid5_conf_t *conf, int num)
 {
-	kmem_cache_t *sc;
+	struct kmem_cache *sc;
 	int devs = conf->raid_disks;
 
 	sprintf(conf->cache_name[0], "raid5/%s", mdname(conf->mddev));
@@ -397,7 +397,7 @@ static int resize_stripes(raid5_conf_t *conf, int newsize)
 	LIST_HEAD(newstripes);
 	struct disk_info *ndisks;
 	int err = 0;
-	kmem_cache_t *sc;
+	struct kmem_cache *sc;
 	int i;
 
 	if (newsize <= conf->pool_size)
@@ -2611,6 +2611,106 @@ static int raid5_congested(void *data, int bits)
 	return 0;
 }
 
+/* We want read requests to align with chunks where possible,
+ * but write requests don't need to.
+ */
+static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
+{
+	mddev_t *mddev = q->queuedata;
+	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	int max;
+	unsigned int chunk_sectors = mddev->chunk_size >> 9;
+	unsigned int bio_sectors = bio->bi_size >> 9;
+
+	if (bio_data_dir(bio))
+		return biovec->bv_len; /* always allow writes to be mergeable */
+
+	max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
+	if (max < 0) max = 0;
+	if (max <= biovec->bv_len && bio_sectors == 0)
+		return biovec->bv_len;
+	else
+		return max;
+}
+
+
+static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
+{
+	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	unsigned int chunk_sectors = mddev->chunk_size >> 9;
+	unsigned int bio_sectors = bio->bi_size >> 9;
+
+	return  chunk_sectors >=
+		((sector & (chunk_sectors - 1)) + bio_sectors);
+}
+
+/*
+ *  The "raid5_align_endio" should check if the read succeeded and if it
+ *  did, call bio_endio on the original bio (having bio_put the new bio
+ *  first).
+ *  If the read failed..
+ */
+int raid5_align_endio(struct bio *bi, unsigned int bytes , int error)
+{
+	struct bio* raid_bi  = bi->bi_private;
+	if (bi->bi_size)
+		return 1;
+	bio_put(bi);
+	bio_endio(raid_bi, bytes, error);
+	return 0;
+}
+
+static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
+{
+	mddev_t *mddev = q->queuedata;
+	raid5_conf_t *conf = mddev_to_conf(mddev);
+	const unsigned int raid_disks = conf->raid_disks;
+	const unsigned int data_disks = raid_disks - 1;
+	unsigned int dd_idx, pd_idx;
+	struct bio* align_bi;
+	mdk_rdev_t *rdev;
+
+	if (!in_chunk_boundary(mddev, raid_bio)) {
+		printk("chunk_aligned_read : non aligned\n");
+		return 0;
+	}
+	/*
+ 	 * use bio_clone to make a copy of the bio
+	 */
+	align_bi = bio_clone(raid_bio, GFP_NOIO);
+	if (!align_bi)
+		return 0;
+	/*
+	 *   set bi_end_io to a new function, and set bi_private to the
+	 *     original bio.
+	 */
+	align_bi->bi_end_io  = raid5_align_endio;
+	align_bi->bi_private = raid_bio;
+	/*
+	 *	compute position
+	 */
+	align_bi->bi_sector =  raid5_compute_sector(raid_bio->bi_sector,
+					raid_disks,
+					data_disks,
+					&dd_idx,
+					&pd_idx,
+					conf);
+
+	rcu_read_lock();
+	rdev = rcu_dereference(conf->disks[dd_idx].rdev);
+	if (rdev && test_bit(In_sync, &rdev->flags)) {
+		align_bi->bi_bdev =  rdev->bdev;
+		atomic_inc(&rdev->nr_pending);
+		rcu_read_unlock();
+		generic_make_request(align_bi);
+		return 1;
+	} else {
+		rcu_read_unlock();
+		return 0;
+	}
+}
+
+
 static int make_request(request_queue_t *q, struct bio * bi)
 {
 	mddev_t *mddev = q->queuedata;
@@ -3320,6 +3420,8 @@ static int run(mddev_t *mddev)
 	mddev->array_size =  mddev->size * (conf->previous_raid_disks -
 					    conf->max_degraded);
 
+	blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
+
 	return 0;
 abort:
 	if (conf) {
@@ -3659,7 +3761,7 @@ static void end_reshape(raid5_conf_t *conf)
 		bdev = bdget_disk(conf->mddev->gendisk, 0);
 		if (bdev) {
 			mutex_lock(&bdev->bd_inode->i_mutex);
-			i_size_write(bdev->bd_inode, conf->mddev->array_size << 10);
+			i_size_write(bdev->bd_inode, (loff_t)conf->mddev->array_size << 10);
 			mutex_unlock(&bdev->bd_inode->i_mutex);
 			bdput(bdev);
 		}