From f31c21e4365c02ccf7226c33ea978cd5dbfc351e Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 22 Nov 2017 14:25:18 +1100 Subject: [PATCH] dm: remove unused 'num_write_bios' target interface No DM target provides num_write_bios and none has since dm-cache's brief use in 2013. Having the possibility of num_write_bios > 1 complicates bio allocation. So remove the interface and assume there is only one bio needed. If a target ever needs more, it must provide a suitable bioset and allocate itself based on its particular needs. Signed-off-by: NeilBrown Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 30 ++++++++++-------------------- include/linux/device-mapper.h | 15 --------------- 2 files changed, 10 insertions(+), 35 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 07dec8ece083..2480c6abe8f1 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1319,32 +1319,22 @@ static int __send_empty_flush(struct clone_info *ci) } static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti, - sector_t sector, unsigned *len) + sector_t sector, unsigned *len) { struct bio *bio = ci->bio; struct dm_target_io *tio; - unsigned target_bio_nr; - unsigned num_target_bios = 1; - int r = 0; + int r; - /* - * Does the target want to receive duplicate copies of the bio? - */ - if (bio_data_dir(bio) == WRITE && ti->num_write_bios) - num_target_bios = ti->num_write_bios(ti, bio); - - for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) { - tio = alloc_tio(ci, ti, target_bio_nr); - tio->len_ptr = len; - r = clone_bio(tio, bio, sector, *len); - if (r < 0) { - free_tio(tio); - break; - } - __map_bio(tio); + tio = alloc_tio(ci, ti, 0); + tio->len_ptr = len; + r = clone_bio(tio, bio, sector, *len); + if (r < 0) { + free_tio(tio); + return r; } + __map_bio(tio); - return r; + return 0; } typedef unsigned (*get_num_bios_fn)(struct dm_target *ti); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index a5538433c927..5a68b366e664 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -220,14 +220,6 @@ struct target_type { #define DM_TARGET_WILDCARD 0x00000008 #define dm_target_is_wildcard(type) ((type)->features & DM_TARGET_WILDCARD) -/* - * Some targets need to be sent the same WRITE bio severals times so - * that they can send copies of it to different devices. This function - * examines any supplied bio and returns the number of copies of it the - * target requires. - */ -typedef unsigned (*dm_num_write_bios_fn) (struct dm_target *ti, struct bio *bio); - /* * A target implements own bio data integrity. */ @@ -291,13 +283,6 @@ struct dm_target { */ unsigned per_io_data_size; - /* - * If defined, this function is called to find out how many - * duplicate bios should be sent to the target when writing - * data. - */ - dm_num_write_bios_fn num_write_bios; - /* target specific data */ void *private; -- 2.20.1