Merge tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...
[firefly-linux-kernel-4.4.55.git] / drivers / md / dm.c
index 2fe0992c14a7926e60acab81447d578862a1ec26..f331d888e7f5a52cd5a2ada7498a5051bd8e38ca 100644 (file)
@@ -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)