diff options
| -rw-r--r-- | drivers/md/dm.c | 44 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 6 | ||||
| -rw-r--r-- | include/linux/dm-ioctl.h | 4 |
3 files changed, 52 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index efe96907492..bca448e1187 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -829,6 +829,49 @@ static int __split_bio(struct mapped_device *md, struct bio *bio) * CRUD END *---------------------------------------------------------------*/ +static int dm_merge_bvec(struct request_queue *q, + struct bvec_merge_data *bvm, + struct bio_vec *biovec) +{ + struct mapped_device *md = q->queuedata; + struct dm_table *map = dm_get_table(md); + struct dm_target *ti; + sector_t max_sectors; + int max_size; + + if (unlikely(!map)) + return 0; + + ti = dm_table_find_target(map, bvm->bi_sector); + + /* + * Find maximum amount of I/O that won't need splitting + */ + max_sectors = min(max_io_len(md, bvm->bi_sector, ti), + (sector_t) BIO_MAX_SECTORS); + max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size; + if (max_size < 0) + max_size = 0; + + /* + * merge_bvec_fn() returns number of bytes + * it can accept at this offset + * max is precomputed maximal io size + */ + if (max_size && ti->type->merge) + max_size = ti->type->merge(ti, bvm, biovec, max_size); + + /* + * Always allow an entire first page + */ + if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT)) + max_size = biovec->bv_len; + + dm_table_put(map); + + return max_size; +} + /* * The request function that just remaps the bio built up by * dm_merge_bvec. @@ -1032,6 +1075,7 @@ static struct mapped_device *alloc_dev(int minor) blk_queue_make_request(md->queue, dm_request); blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); md->queue->unplug_fn = dm_unplug_all; + blk_queue_merge_bvec(md->queue, dm_merge_bvec); md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache); if (!md->io_pool) diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 0d8d419d191..a90222e3297 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -9,11 +9,13 @@ #define _LINUX_DEVICE_MAPPER_H #include <linux/bio.h> +#include <linux/blkdev.h> struct dm_target; struct dm_table; struct dm_dev; struct mapped_device; +struct bio_vec; typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; @@ -72,6 +74,9 @@ typedef int (*dm_ioctl_fn) (struct dm_target *ti, struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg); +typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, + struct bio_vec *biovec, int max_size); + void dm_error(const char *message); /* @@ -107,6 +112,7 @@ struct target_type { dm_status_fn status; dm_message_fn message; dm_ioctl_fn ioctl; + dm_merge_fn merge; }; struct io_restrictions { diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index b03c41bbfa1..28c2940eb30 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -256,9 +256,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 13 +#define DM_VERSION_MINOR 14 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2007-10-18)" +#define DM_VERSION_EXTRA "-ioctl (2008-04-23)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ |