From 8ae126660fddbeebb9251a174e6fa45b6ad8f932 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 27 Apr 2015 23:48:34 -0700 Subject: 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 Cc: Lars Ellenberg Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina Cc: Yehuda Sadeh Cc: Sage Weil Cc: Alex Elder Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Neil Brown Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig Cc: "Martin K. Petersen" Acked-by: NeilBrown (for the 'md' bits) Acked-by: Mike Snitzer Signed-off-by: Kent Overstreet [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- drivers/md/dm.c | 127 +------------------------------------------------------- 1 file changed, 2 insertions(+), 125 deletions(-) (limited to 'drivers/md/dm.c') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 069f8d7e890e..8bb1ebb6ca7b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -124,9 +124,8 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); #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 @@ static void __split_and_process_bio(struct mapped_device *md, * 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. @@ -2507,59 +2445,6 @@ static void __set_size(struct mapped_device *md, sector_t size) i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT); } -/* - * 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. */ @@ -2569,7 +2454,6 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, 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 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, __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 @@ int dm_setup_md_queue(struct mapped_device *md) 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; } -- cgit v1.2.3