Update multipath_init_per_bio_data() to allocate a dm_mpath_per_bio_data structure and associate it with the noclone bio using the dm_noclone structure's 'noclone_private' member.
If kmem_cache_alloc() fails to allocate a struct dm_mpath_per_bio_data, DM_MAPIO_NOCLONE_FAILED is returned from ->map and DM core falls back to using traditional bio-based DM's bio cloning. Signed-off-by: Mike Snitzer <[email protected]> --- drivers/md/dm-mpath.c | 65 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 10 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 2ee5e357a0a7..ac7ca5334796 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -30,6 +30,8 @@ #define DM_PG_INIT_DELAY_MSECS 2000 #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) +static struct kmem_cache *_noclone_per_bio_data_cache; + /* Path properties */ struct pgpath { struct list_head list; @@ -101,6 +103,11 @@ struct dm_mpath_io { size_t nr_bytes; }; +struct dm_mpath_per_bio_data { + struct dm_mpath_io mpio; + struct dm_bio_details bio_details; +}; + typedef int (*action_fn) (struct pgpath *pgpath); static struct workqueue_struct *kmultipathd, *kmpath_handlerd; @@ -250,11 +257,16 @@ static struct dm_mpath_io *get_mpio(union map_info *info) static size_t multipath_per_bio_data_size(void) { - return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details); + return sizeof(struct dm_mpath_per_bio_data); } static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio) { + struct dm_noclone *noclone = dm_get_noclone_from_bio(bio); + + if (noclone) + return noclone->noclone_private; + return dm_per_bio_data(bio, multipath_per_bio_data_size()); } @@ -265,16 +277,29 @@ static struct dm_bio_details *get_bio_details_from_mpio(struct dm_mpath_io *mpio return bio_details; } -static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p) +static bool multipath_init_per_bio_data(struct dm_target *ti, struct bio *bio, + struct dm_mpath_io **mpio_p) { - struct dm_mpath_io *mpio = get_mpio_from_bio(bio); - struct dm_bio_details *bio_details = get_bio_details_from_mpio(mpio); + struct dm_mpath_io *mpio; + struct dm_bio_details *bio_details; + struct dm_noclone *noclone = dm_get_noclone_from_bio(bio); + + if (noclone) { + noclone->noclone_private = + kmem_cache_alloc(_noclone_per_bio_data_cache, GFP_NOWAIT); + if (unlikely(!noclone->noclone_private)) + return false; + } + + mpio = get_mpio_from_bio(bio); + bio_details = get_bio_details_from_mpio(mpio); mpio->nr_bytes = bio->bi_iter.bi_size; mpio->pgpath = NULL; *mpio_p = mpio; dm_bio_record(bio_details, bio); + return true; } /*----------------------------------------------- @@ -652,7 +677,9 @@ static int multipath_map_bio(struct dm_target *ti, struct bio *bio) struct multipath *m = ti->private; struct dm_mpath_io *mpio = NULL; - multipath_init_per_bio_data(bio, &mpio); + if (!multipath_init_per_bio_data(ti, bio, &mpio)) + return DM_MAPIO_NOCLONE_FAILED; + return __multipath_map_bio(m, bio, mpio); } @@ -1178,9 +1205,10 @@ static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) ti->num_discard_bios = 1; ti->num_write_same_bios = 1; ti->num_write_zeroes_bios = 1; - if (m->queue_mode == DM_TYPE_BIO_BASED) + if (m->queue_mode == DM_TYPE_BIO_BASED) { + ti->no_clone = true; ti->per_io_data_size = multipath_per_bio_data_size(); - else + } else ti->per_io_data_size = sizeof(struct dm_mpath_io); return 0; @@ -1584,12 +1612,13 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone, return r; } -static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, +static int multipath_end_io_bio(struct dm_target *ti, struct bio *bio, blk_status_t *error) { struct multipath *m = ti->private; - struct dm_mpath_io *mpio = get_mpio_from_bio(clone); + struct dm_mpath_io *mpio = get_mpio_from_bio(bio); struct pgpath *pgpath = mpio->pgpath; + struct dm_noclone *noclone = NULL; unsigned long flags; int r = DM_ENDIO_DONE; @@ -1611,7 +1640,7 @@ static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, } spin_lock_irqsave(&m->lock, flags); - bio_list_add(&m->queued_bios, clone); + bio_list_add(&m->queued_bios, bio); spin_unlock_irqrestore(&m->lock, flags); if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) queue_work(kmultipathd, &m->process_queued_bios); @@ -1625,6 +1654,12 @@ static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); } + if (r != DM_ENDIO_INCOMPLETE) { + noclone = dm_get_noclone_from_bio(bio); + if (noclone) + kmem_cache_free(_noclone_per_bio_data_cache, noclone->noclone_private); + } + return r; } @@ -2057,6 +2092,13 @@ static int __init dm_multipath_init(void) goto bad_alloc_kmpath_handlerd; } + _noclone_per_bio_data_cache = KMEM_CACHE(dm_mpath_per_bio_data, 0); + if (!_noclone_per_bio_data_cache) { + DMERR("failed to create noclone_per_bio_data_cache"); + r = -ENOMEM; + goto bad_noclone_pbd; + } + r = dm_register_target(&multipath_target); if (r < 0) { DMERR("request-based register failed %d", r); @@ -2067,6 +2109,8 @@ static int __init dm_multipath_init(void) return 0; bad_register_target: + kmem_cache_destroy(_noclone_per_bio_data_cache); +bad_noclone_pbd: destroy_workqueue(kmpath_handlerd); bad_alloc_kmpath_handlerd: destroy_workqueue(kmultipathd); @@ -2078,6 +2122,7 @@ static void __exit dm_multipath_exit(void) { destroy_workqueue(kmpath_handlerd); destroy_workqueue(kmultipathd); + kmem_cache_destroy(_noclone_per_bio_data_cache); dm_unregister_target(&multipath_target); } -- 2.15.0 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
