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 <snitzer@xxxxxxxxxx>
---
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
--
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