block: kill merge_bvec_fn() completely
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 069f8d7..8bb1ebb 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -124,9 +124,8 @@
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
-#define DMF_MERGE_IS_OPTIONAL 6
-#define DMF_DEFERRED_REMOVE 7
-#define DMF_SUSPENDED_INTERNALLY 8
+#define DMF_DEFERRED_REMOVE 6
+#define DMF_SUSPENDED_INTERNALLY 7
/*
* A dummy definition to make RCU happy.
@@ -1725,67 +1724,6 @@
* 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_live_table_fast(md);
- struct dm_target *ti;
- sector_t max_sectors, max_size = 0;
-
- if (unlikely(!map))
- goto out;
-
- ti = dm_table_find_target(map, bvm->bi_sector);
- if (!dm_target_is_valid(ti))
- goto out;
-
- /*
- * Find maximum amount of I/O that won't need splitting
- */
- max_sectors = min(max_io_len(bvm->bi_sector, ti),
- (sector_t) queue_max_sectors(q));
- max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
-
- /*
- * FIXME: this stop-gap fix _must_ be cleaned up (by passing a sector_t
- * to the targets' merge function since it holds sectors not bytes).
- * Just doing this as an interim fix for stable@ because the more
- * comprehensive cleanup of switching to sector_t will impact every
- * DM target that implements a ->merge hook.
- */
- if (max_size > INT_MAX)
- max_size = INT_MAX;
-
- /*
- * 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, (int) max_size);
- /*
- * If the target doesn't support merge method and some of the devices
- * provided their merge_bvec method (we know this by looking for the
- * max_hw_sectors that dm_set_device_limits may set), then we can't
- * allow bios with multiple vector entries. So always set max_size
- * to 0, and the code below allows just one page.
- */
- else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
- max_size = 0;
-
-out:
- dm_put_live_table_fast(md);
- /*
- * Always allow an entire first page
- */
- if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
- max_size = biovec->bv_len;
-
- return max_size;
-}
-
/*
* The request function that just remaps the bio built up by
* dm_merge_bvec.
@@ -2508,59 +2446,6 @@
}
/*
- * Return 1 if the queue has a compulsory merge_bvec_fn function.
- *
- * If this function returns 0, then the device is either a non-dm
- * device without a merge_bvec_fn, or it is a dm device that is
- * able to split any bios it receives that are too big.
- */
-int dm_queue_merge_is_compulsory(struct request_queue *q)
-{
- struct mapped_device *dev_md;
-
- if (!q->merge_bvec_fn)
- return 0;
-
- if (q->make_request_fn == dm_make_request) {
- dev_md = q->queuedata;
- if (test_bit(DMF_MERGE_IS_OPTIONAL, &dev_md->flags))
- return 0;
- }
-
- return 1;
-}
-
-static int dm_device_merge_is_compulsory(struct dm_target *ti,
- struct dm_dev *dev, sector_t start,
- sector_t len, void *data)
-{
- struct block_device *bdev = dev->bdev;
- struct request_queue *q = bdev_get_queue(bdev);
-
- return dm_queue_merge_is_compulsory(q);
-}
-
-/*
- * Return 1 if it is acceptable to ignore merge_bvec_fn based
- * on the properties of the underlying devices.
- */
-static int dm_table_merge_is_optional(struct dm_table *table)
-{
- unsigned i = 0;
- struct dm_target *ti;
-
- while (i < dm_table_get_num_targets(table)) {
- ti = dm_table_get_target(table, i++);
-
- if (ti->type->iterate_devices &&
- ti->type->iterate_devices(ti, dm_device_merge_is_compulsory, NULL))
- return 0;
- }
-
- return 1;
-}
-
-/*
* Returns old map, which caller must destroy.
*/
static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
@@ -2569,7 +2454,6 @@
struct dm_table *old_map;
struct request_queue *q = md->queue;
sector_t size;
- int merge_is_optional;
size = dm_table_get_size(t);
@@ -2595,17 +2479,11 @@
__bind_mempools(md, t);
- merge_is_optional = dm_table_merge_is_optional(t);
-
old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
rcu_assign_pointer(md->map, t);
md->immutable_target_type = dm_table_get_immutable_target_type(t);
dm_table_set_restrictions(t, q, limits);
- if (merge_is_optional)
- set_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
- else
- clear_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
if (old_map)
dm_sync_table(md);
@@ -2886,7 +2764,6 @@
case DM_TYPE_BIO_BASED:
dm_init_old_md_queue(md);
blk_queue_make_request(md->queue, dm_make_request);
- blk_queue_merge_bvec(md->queue, dm_merge_bvec);
break;
}