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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 12:35:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 12:35:01 -0700
commit22165fa79814e71e7a5974b3c37a5028ed16c8f9 (patch)
tree2dd55b3e3d21017410a0f1b1c2c0281fe4bc8e6c /drivers/md/dm.c
parenta2f54be94f4cbce269bca6188d3fb4310c346fd1 (diff)
parentb5451e456840af027b794afc2c7c84c2a17f569b (diff)
downloadlinux-22165fa79814e71e7a5974b3c37a5028ed16c8f9.tar.bz2
Merge tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer: "Apologies for not pressing this request-based DM partial completion issue further, it was an oversight on my part. We'll have to get it fixed up properly and revisit for a future release. - Revert block and DM core changes the removed request-based DM's ability to handle partial request completions -- otherwise with the current SCSI LLDs these changes could lead to silent data corruption. - Fix two DM version bumps that were missing from the initial 4.2 DM pull request (enabled userspace lvm2 to know certain changes have been made)" * tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache policy smq: fix "default" version to be 1.4.0 dm: bump the ioctl version to 4.32.0 Revert "block, dm: don't copy bios for request clones" Revert "dm: do not allocate any mempools for blk-mq request-based DM"
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c220
1 files changed, 152 insertions, 68 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2fe0992c14a7..f331d888e7f5 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -993,6 +993,57 @@ static void clone_endio(struct bio *bio, int error)
dec_pending(io, error);
}
+/*
+ * Partial completion handling for request-based dm
+ */
+static void end_clone_bio(struct bio *clone, int error)
+{
+ struct dm_rq_clone_bio_info *info =
+ container_of(clone, struct dm_rq_clone_bio_info, clone);
+ struct dm_rq_target_io *tio = info->tio;
+ struct bio *bio = info->orig;
+ unsigned int nr_bytes = info->orig->bi_iter.bi_size;
+
+ bio_put(clone);
+
+ if (tio->error)
+ /*
+ * An error has already been detected on the request.
+ * Once error occurred, just let clone->end_io() handle
+ * the remainder.
+ */
+ return;
+ else if (error) {
+ /*
+ * Don't notice the error to the upper layer yet.
+ * The error handling decision is made by the target driver,
+ * when the request is completed.
+ */
+ tio->error = error;
+ return;
+ }
+
+ /*
+ * I/O for the bio successfully completed.
+ * Notice the data completion to the upper layer.
+ */
+
+ /*
+ * bios are processed from the head of the list.
+ * So the completing bio should always be rq->bio.
+ * If it's not, something wrong is happening.
+ */
+ if (tio->orig->bio != bio)
+ DMERR("bio completion is going in the middle of the request");
+
+ /*
+ * Update the original request.
+ * Do not use blk_end_request() here, because it may complete
+ * the original request before the clone, and break the ordering.
+ */
+ blk_update_request(tio->orig, 0, nr_bytes);
+}
+
static struct dm_rq_target_io *tio_from_request(struct request *rq)
{
return (rq->q->mq_ops ? blk_mq_rq_to_pdu(rq) : rq->special);
@@ -1050,6 +1101,8 @@ static void free_rq_clone(struct request *clone)
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
+ blk_rq_unprep_clone(clone);
+
if (md->type == DM_TYPE_MQ_REQUEST_BASED)
/* stacked on blk-mq queue(s) */
tio->ti->type->release_clone_rq(clone);
@@ -1784,13 +1837,39 @@ static void dm_dispatch_clone_request(struct request *clone, struct request *rq)
dm_complete_request(rq, r);
}
-static void setup_clone(struct request *clone, struct request *rq,
- struct dm_rq_target_io *tio)
+static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
+ void *data)
+{
+ struct dm_rq_target_io *tio = data;
+ struct dm_rq_clone_bio_info *info =
+ container_of(bio, struct dm_rq_clone_bio_info, clone);
+
+ info->orig = bio_orig;
+ info->tio = tio;
+ bio->bi_end_io = end_clone_bio;
+
+ return 0;
+}
+
+static int setup_clone(struct request *clone, struct request *rq,
+ struct dm_rq_target_io *tio, gfp_t gfp_mask)
{
- blk_rq_prep_clone(clone, rq);
+ int r;
+
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, gfp_mask,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
+
tio->clone = clone;
+
+ return 0;
}
static struct request *clone_rq(struct request *rq, struct mapped_device *md,
@@ -1811,7 +1890,12 @@ static struct request *clone_rq(struct request *rq, struct mapped_device *md,
clone = tio->clone;
blk_rq_init(NULL, clone);
- setup_clone(clone, rq, tio);
+ if (setup_clone(clone, rq, tio, gfp_mask)) {
+ /* -ENOMEM */
+ if (alloc_clone)
+ free_clone_request(md, clone);
+ return NULL;
+ }
return clone;
}
@@ -1905,7 +1989,11 @@ static int map_request(struct dm_rq_target_io *tio, struct request *rq,
}
if (r != DM_MAPIO_REMAPPED)
return r;
- setup_clone(clone, rq, tio);
+ if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
+ /* -ENOMEM */
+ ti->type->release_clone_rq(clone);
+ return DM_MAPIO_REQUEUE;
+ }
}
switch (r) {
@@ -2349,42 +2437,30 @@ static void free_dev(struct mapped_device *md)
kfree(md);
}
-static unsigned filter_md_type(unsigned type, struct mapped_device *md)
-{
- if (type == DM_TYPE_BIO_BASED)
- return type;
-
- return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;
-}
-
static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
{
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
- switch (filter_md_type(dm_table_get_type(t), md)) {
- case DM_TYPE_BIO_BASED:
- if (md->bs && md->io_pool) {
+ if (md->bs) {
+ /* The md already has necessary mempools. */
+ if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) {
/*
- * This bio-based md already has necessary mempools.
* Reload bioset because front_pad may have changed
* because a different table was loaded.
*/
bioset_free(md->bs);
md->bs = p->bs;
p->bs = NULL;
- goto out;
}
- break;
- case DM_TYPE_REQUEST_BASED:
- if (md->rq_pool && md->io_pool)
- /*
- * This request-based md already has necessary mempools.
- */
- goto out;
- break;
- case DM_TYPE_MQ_REQUEST_BASED:
- BUG_ON(p); /* No mempools needed */
- return;
+ /*
+ * There's no need to reload with request-based dm
+ * because the size of front_pad doesn't change.
+ * Note for future: If you are to reload bioset,
+ * prep-ed requests in the queue may refer
+ * to bio from the old bioset, so you must walk
+ * through the queue to unprep.
+ */
+ goto out;
}
BUG_ON(!p || md->io_pool || md->rq_pool || md->bs);
@@ -2395,6 +2471,7 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
p->rq_pool = NULL;
md->bs = p->bs;
p->bs = NULL;
+
out:
/* mempool bind completed, no longer need any mempools in the table */
dm_table_free_md_mempools(t);
@@ -2774,6 +2851,14 @@ out_tag_set:
return err;
}
+static unsigned filter_md_type(unsigned type, struct mapped_device *md)
+{
+ if (type == DM_TYPE_BIO_BASED)
+ return type;
+
+ return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;
+}
+
/*
* Setup the DM device's queue based on md's type
*/
@@ -3486,23 +3571,48 @@ int dm_noflush_suspending(struct dm_target *ti)
}
EXPORT_SYMBOL_GPL(dm_noflush_suspending);
-struct dm_md_mempools *dm_alloc_bio_mempools(unsigned integrity,
- unsigned per_bio_data_size)
+struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
+ unsigned integrity, unsigned per_bio_data_size)
{
- struct dm_md_mempools *pools;
- unsigned int pool_size = dm_get_reserved_bio_based_ios();
+ struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL);
+ struct kmem_cache *cachep = NULL;
+ unsigned int pool_size = 0;
unsigned int front_pad;
- pools = kzalloc(sizeof(*pools), GFP_KERNEL);
if (!pools)
- return ERR_PTR(-ENOMEM);
+ return NULL;
- front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) +
- offsetof(struct dm_target_io, clone);
+ type = filter_md_type(type, md);
- pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
- if (!pools->io_pool)
- goto out;
+ switch (type) {
+ case DM_TYPE_BIO_BASED:
+ cachep = _io_cache;
+ pool_size = dm_get_reserved_bio_based_ios();
+ front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
+ break;
+ case DM_TYPE_REQUEST_BASED:
+ cachep = _rq_tio_cache;
+ pool_size = dm_get_reserved_rq_based_ios();
+ pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
+ if (!pools->rq_pool)
+ goto out;
+ /* fall through to setup remaining rq-based pools */
+ case DM_TYPE_MQ_REQUEST_BASED:
+ if (!pool_size)
+ pool_size = dm_get_reserved_rq_based_ios();
+ front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
+ /* per_bio_data_size is not used. See __bind_mempools(). */
+ WARN_ON(per_bio_data_size != 0);
+ break;
+ default:
+ BUG();
+ }
+
+ if (cachep) {
+ pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
+ if (!pools->io_pool)
+ goto out;
+ }
pools->bs = bioset_create_nobvec(pool_size, front_pad);
if (!pools->bs)
@@ -3512,37 +3622,11 @@ struct dm_md_mempools *dm_alloc_bio_mempools(unsigned integrity,
goto out;
return pools;
-out:
- dm_free_md_mempools(pools);
- return ERR_PTR(-ENOMEM);
-}
-struct dm_md_mempools *dm_alloc_rq_mempools(struct mapped_device *md,
- unsigned type)
-{
- unsigned int pool_size;
- struct dm_md_mempools *pools;
-
- if (filter_md_type(type, md) == DM_TYPE_MQ_REQUEST_BASED)
- return NULL; /* No mempools needed */
-
- pool_size = dm_get_reserved_rq_based_ios();
- pools = kzalloc(sizeof(*pools), GFP_KERNEL);
- if (!pools)
- return ERR_PTR(-ENOMEM);
-
- pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
- if (!pools->rq_pool)
- goto out;
-
- pools->io_pool = mempool_create_slab_pool(pool_size, _rq_tio_cache);
- if (!pools->io_pool)
- goto out;
-
- return pools;
out:
dm_free_md_mempools(pools);
- return ERR_PTR(-ENOMEM);
+
+ return NULL;
}
void dm_free_md_mempools(struct dm_md_mempools *pools)