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path: root/drivers/block/xen-blkfront.c
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Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c1061
1 files changed, 715 insertions, 346 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2fee2eef988d..8a8dc91c39f7 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -60,6 +60,20 @@
#include <asm/xen/hypervisor.h>
+/*
+ * The minimal size of segment supported by the block framework is PAGE_SIZE.
+ * When Linux is using a different page size than Xen, it may not be possible
+ * to put all the data in a single segment.
+ * This can happen when the backend doesn't support indirect descriptor and
+ * therefore the maximum amount of data that a request can carry is
+ * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE = 44KB
+ *
+ * Note that we only support one extra request. So the Linux page size
+ * should be <= ( 2 * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) =
+ * 88KB.
+ */
+#define HAS_EXTRA_REQ (BLKIF_MAX_SEGMENTS_PER_REQUEST < XEN_PFN_PER_PAGE)
+
enum blkif_state {
BLKIF_STATE_DISCONNECTED,
BLKIF_STATE_CONNECTED,
@@ -72,6 +86,13 @@ struct grant {
struct list_head node;
};
+enum blk_req_status {
+ REQ_WAITING,
+ REQ_DONE,
+ REQ_ERROR,
+ REQ_EOPNOTSUPP,
+};
+
struct blk_shadow {
struct blkif_request req;
struct request *request;
@@ -79,6 +100,14 @@ struct blk_shadow {
struct grant **indirect_grants;
struct scatterlist *sg;
unsigned int num_sg;
+ enum blk_req_status status;
+
+ #define NO_ASSOCIATED_ID ~0UL
+ /*
+ * Id of the sibling if we ever need 2 requests when handling a
+ * block I/O request
+ */
+ unsigned long associated_id;
};
struct split_bio {
@@ -99,6 +128,10 @@ static unsigned int xen_blkif_max_segments = 32;
module_param_named(max, xen_blkif_max_segments, int, S_IRUGO);
MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)");
+static unsigned int xen_blkif_max_queues = 4;
+module_param_named(max_queues, xen_blkif_max_queues, uint, S_IRUGO);
+MODULE_PARM_DESC(max_queues, "Maximum number of hardware queues/rings used per virtual disk");
+
/*
* Maximum order of pages to be used for the shared ring between front and
* backend, 4KB page granularity is used.
@@ -114,10 +147,35 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
__CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * XENBUS_MAX_RING_GRANTS)
/*
- * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
- * characters are enough. Define to 20 to keep consist with backend.
+ * ring-ref%u i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
+ * characters are enough. Define to 20 to keep consistent with backend.
*/
#define RINGREF_NAME_LEN (20)
+/*
+ * queue-%u would take 7 + 10(UINT_MAX) = 17 characters.
+ */
+#define QUEUE_NAME_LEN (17)
+
+/*
+ * Per-ring info.
+ * Every blkfront device can associate with one or more blkfront_ring_info,
+ * depending on how many hardware queues/rings to be used.
+ */
+struct blkfront_ring_info {
+ /* Lock to protect data in every ring buffer. */
+ spinlock_t ring_lock;
+ struct blkif_front_ring ring;
+ unsigned int ring_ref[XENBUS_MAX_RING_GRANTS];
+ unsigned int evtchn, irq;
+ struct work_struct work;
+ struct gnttab_free_callback callback;
+ struct blk_shadow shadow[BLK_MAX_RING_SIZE];
+ struct list_head indirect_pages;
+ struct list_head grants;
+ unsigned int persistent_gnts_c;
+ unsigned long shadow_free;
+ struct blkfront_info *dev_info;
+};
/*
* We have one of these per vbd, whether ide, scsi or 'other'. They
@@ -126,25 +184,15 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
*/
struct blkfront_info
{
- spinlock_t io_lock;
struct mutex mutex;
struct xenbus_device *xbdev;
struct gendisk *gd;
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int ring_ref[XENBUS_MAX_RING_GRANTS];
+ /* Number of pages per ring buffer. */
unsigned int nr_ring_pages;
- struct blkif_front_ring ring;
- unsigned int evtchn, irq;
struct request_queue *rq;
- struct work_struct work;
- struct gnttab_free_callback callback;
- struct blk_shadow shadow[BLK_MAX_RING_SIZE];
- struct list_head grants;
- struct list_head indirect_pages;
- unsigned int persistent_gnts_c;
- unsigned long shadow_free;
unsigned int feature_flush;
unsigned int feature_discard:1;
unsigned int feature_secdiscard:1;
@@ -155,6 +203,8 @@ struct blkfront_info
unsigned int max_indirect_segments;
int is_ready;
struct blk_mq_tag_set tag_set;
+ struct blkfront_ring_info *rinfo;
+ unsigned int nr_rings;
};
static unsigned int nr_minors;
@@ -198,38 +248,40 @@ static DEFINE_SPINLOCK(minor_lock);
#define GREFS(_psegs) ((_psegs) * GRANTS_PER_PSEG)
-static int blkfront_setup_indirect(struct blkfront_info *info);
-static int blkfront_gather_backend_features(struct blkfront_info *info);
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
+static void blkfront_gather_backend_features(struct blkfront_info *info);
-static int get_id_from_freelist(struct blkfront_info *info)
+static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
{
- unsigned long free = info->shadow_free;
- BUG_ON(free >= BLK_RING_SIZE(info));
- info->shadow_free = info->shadow[free].req.u.rw.id;
- info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
+ unsigned long free = rinfo->shadow_free;
+
+ BUG_ON(free >= BLK_RING_SIZE(rinfo->dev_info));
+ rinfo->shadow_free = rinfo->shadow[free].req.u.rw.id;
+ rinfo->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
return free;
}
-static int add_id_to_freelist(struct blkfront_info *info,
- unsigned long id)
+static int add_id_to_freelist(struct blkfront_ring_info *rinfo,
+ unsigned long id)
{
- if (info->shadow[id].req.u.rw.id != id)
+ if (rinfo->shadow[id].req.u.rw.id != id)
return -EINVAL;
- if (info->shadow[id].request == NULL)
+ if (rinfo->shadow[id].request == NULL)
return -EINVAL;
- info->shadow[id].req.u.rw.id = info->shadow_free;
- info->shadow[id].request = NULL;
- info->shadow_free = id;
+ rinfo->shadow[id].req.u.rw.id = rinfo->shadow_free;
+ rinfo->shadow[id].request = NULL;
+ rinfo->shadow_free = id;
return 0;
}
-static int fill_grant_buffer(struct blkfront_info *info, int num)
+static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num)
{
+ struct blkfront_info *info = rinfo->dev_info;
struct page *granted_page;
struct grant *gnt_list_entry, *n;
int i = 0;
- while(i < num) {
+ while (i < num) {
gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO);
if (!gnt_list_entry)
goto out_of_memory;
@@ -244,7 +296,7 @@ static int fill_grant_buffer(struct blkfront_info *info, int num)
}
gnt_list_entry->gref = GRANT_INVALID_REF;
- list_add(&gnt_list_entry->node, &info->grants);
+ list_add(&gnt_list_entry->node, &rinfo->grants);
i++;
}
@@ -252,7 +304,7 @@ static int fill_grant_buffer(struct blkfront_info *info, int num)
out_of_memory:
list_for_each_entry_safe(gnt_list_entry, n,
- &info->grants, node) {
+ &rinfo->grants, node) {
list_del(&gnt_list_entry->node);
if (info->feature_persistent)
__free_page(gnt_list_entry->page);
@@ -263,17 +315,17 @@ out_of_memory:
return -ENOMEM;
}
-static struct grant *get_free_grant(struct blkfront_info *info)
+static struct grant *get_free_grant(struct blkfront_ring_info *rinfo)
{
struct grant *gnt_list_entry;
- BUG_ON(list_empty(&info->grants));
- gnt_list_entry = list_first_entry(&info->grants, struct grant,
+ BUG_ON(list_empty(&rinfo->grants));
+ gnt_list_entry = list_first_entry(&rinfo->grants, struct grant,
node);
list_del(&gnt_list_entry->node);
if (gnt_list_entry->gref != GRANT_INVALID_REF)
- info->persistent_gnts_c--;
+ rinfo->persistent_gnts_c--;
return gnt_list_entry;
}
@@ -289,9 +341,10 @@ static inline void grant_foreign_access(const struct grant *gnt_list_entry,
static struct grant *get_grant(grant_ref_t *gref_head,
unsigned long gfn,
- struct blkfront_info *info)
+ struct blkfront_ring_info *rinfo)
{
- struct grant *gnt_list_entry = get_free_grant(info);
+ struct grant *gnt_list_entry = get_free_grant(rinfo);
+ struct blkfront_info *info = rinfo->dev_info;
if (gnt_list_entry->gref != GRANT_INVALID_REF)
return gnt_list_entry;
@@ -312,9 +365,10 @@ static struct grant *get_grant(grant_ref_t *gref_head,
}
static struct grant *get_indirect_grant(grant_ref_t *gref_head,
- struct blkfront_info *info)
+ struct blkfront_ring_info *rinfo)
{
- struct grant *gnt_list_entry = get_free_grant(info);
+ struct grant *gnt_list_entry = get_free_grant(rinfo);
+ struct blkfront_info *info = rinfo->dev_info;
if (gnt_list_entry->gref != GRANT_INVALID_REF)
return gnt_list_entry;
@@ -326,8 +380,8 @@ static struct grant *get_indirect_grant(grant_ref_t *gref_head,
struct page *indirect_page;
/* Fetch a pre-allocated page to use for indirect grefs */
- BUG_ON(list_empty(&info->indirect_pages));
- indirect_page = list_first_entry(&info->indirect_pages,
+ BUG_ON(list_empty(&rinfo->indirect_pages));
+ indirect_page = list_first_entry(&rinfo->indirect_pages,
struct page, lru);
list_del(&indirect_page->lru);
gnt_list_entry->page = indirect_page;
@@ -403,8 +457,8 @@ static void xlbd_release_minors(unsigned int minor, unsigned int nr)
static void blkif_restart_queue_callback(void *arg)
{
- struct blkfront_info *info = (struct blkfront_info *)arg;
- schedule_work(&info->work);
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)arg;
+ schedule_work(&rinfo->work);
}
static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg)
@@ -456,16 +510,33 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
return 0;
}
-static int blkif_queue_discard_req(struct request *req)
+static unsigned long blkif_ring_get_request(struct blkfront_ring_info *rinfo,
+ struct request *req,
+ struct blkif_request **ring_req)
{
- struct blkfront_info *info = req->rq_disk->private_data;
+ unsigned long id;
+
+ *ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt);
+ rinfo->ring.req_prod_pvt++;
+
+ id = get_id_from_freelist(rinfo);
+ rinfo->shadow[id].request = req;
+ rinfo->shadow[id].status = REQ_WAITING;
+ rinfo->shadow[id].associated_id = NO_ASSOCIATED_ID;
+
+ (*ring_req)->u.rw.id = id;
+
+ return id;
+}
+
+static int blkif_queue_discard_req(struct request *req, struct blkfront_ring_info *rinfo)
+{
+ struct blkfront_info *info = rinfo->dev_info;
struct blkif_request *ring_req;
unsigned long id;
/* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
- id = get_id_from_freelist(info);
- info->shadow[id].request = req;
+ id = blkif_ring_get_request(rinfo, req, &ring_req);
ring_req->operation = BLKIF_OP_DISCARD;
ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
@@ -476,10 +547,8 @@ static int blkif_queue_discard_req(struct request *req)
else
ring_req->u.discard.flag = 0;
- info->ring.req_prod_pvt++;
-
/* Keep a private copy so we can reissue requests when recovering. */
- info->shadow[id].req = *ring_req;
+ rinfo->shadow[id].req = *ring_req;
return 0;
}
@@ -487,7 +556,7 @@ static int blkif_queue_discard_req(struct request *req)
struct setup_rw_req {
unsigned int grant_idx;
struct blkif_request_segment *segments;
- struct blkfront_info *info;
+ struct blkfront_ring_info *rinfo;
struct blkif_request *ring_req;
grant_ref_t gref_head;
unsigned int id;
@@ -495,6 +564,9 @@ struct setup_rw_req {
bool need_copy;
unsigned int bvec_off;
char *bvec_data;
+
+ bool require_extra_req;
+ struct blkif_request *extra_ring_req;
};
static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
@@ -507,8 +579,24 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
/* Convenient aliases */
unsigned int grant_idx = setup->grant_idx;
struct blkif_request *ring_req = setup->ring_req;
- struct blkfront_info *info = setup->info;
- struct blk_shadow *shadow = &info->shadow[setup->id];
+ struct blkfront_ring_info *rinfo = setup->rinfo;
+ /*
+ * We always use the shadow of the first request to store the list
+ * of grant associated to the block I/O request. This made the
+ * completion more easy to handle even if the block I/O request is
+ * split.
+ */
+ struct blk_shadow *shadow = &rinfo->shadow[setup->id];
+
+ if (unlikely(setup->require_extra_req &&
+ grant_idx >= BLKIF_MAX_SEGMENTS_PER_REQUEST)) {
+ /*
+ * We are using the second request, setup grant_idx
+ * to be the index of the segment array.
+ */
+ grant_idx -= BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ ring_req = setup->extra_ring_req;
+ }
if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
(grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) {
@@ -516,15 +604,19 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
kunmap_atomic(setup->segments);
n = grant_idx / GRANTS_PER_INDIRECT_FRAME;
- gnt_list_entry = get_indirect_grant(&setup->gref_head, info);
+ gnt_list_entry = get_indirect_grant(&setup->gref_head, rinfo);
shadow->indirect_grants[n] = gnt_list_entry;
setup->segments = kmap_atomic(gnt_list_entry->page);
ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref;
}
- gnt_list_entry = get_grant(&setup->gref_head, gfn, info);
+ gnt_list_entry = get_grant(&setup->gref_head, gfn, rinfo);
ref = gnt_list_entry->gref;
- shadow->grants_used[grant_idx] = gnt_list_entry;
+ /*
+ * All the grants are stored in the shadow of the first
+ * request. Therefore we have to use the global index.
+ */
+ shadow->grants_used[setup->grant_idx] = gnt_list_entry;
if (setup->need_copy) {
void *shared_data;
@@ -566,16 +658,36 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
(setup->grant_idx)++;
}
-static int blkif_queue_rw_req(struct request *req)
+static void blkif_setup_extra_req(struct blkif_request *first,
+ struct blkif_request *second)
{
- struct blkfront_info *info = req->rq_disk->private_data;
- struct blkif_request *ring_req;
- unsigned long id;
+ uint16_t nr_segments = first->u.rw.nr_segments;
+
+ /*
+ * The second request is only present when the first request uses
+ * all its segments. It's always the continuity of the first one.
+ */
+ first->u.rw.nr_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+
+ second->u.rw.nr_segments = nr_segments - BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ second->u.rw.sector_number = first->u.rw.sector_number +
+ (BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) / 512;
+
+ second->u.rw.handle = first->u.rw.handle;
+ second->operation = first->operation;
+}
+
+static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo)
+{
+ struct blkfront_info *info = rinfo->dev_info;
+ struct blkif_request *ring_req, *extra_ring_req = NULL;
+ unsigned long id, extra_id = NO_ASSOCIATED_ID;
+ bool require_extra_req = false;
int i;
struct setup_rw_req setup = {
.grant_idx = 0,
.segments = NULL,
- .info = info,
+ .rinfo = rinfo,
.need_copy = rq_data_dir(req) && info->feature_persistent,
};
@@ -584,7 +696,6 @@ static int blkif_queue_rw_req(struct request *req)
* existing persistent grants, or if we have to get new grants,
* as there are not sufficiently many free.
*/
- bool new_persistent_gnts;
struct scatterlist *sg;
int num_sg, max_grefs, num_grant;
@@ -596,41 +707,36 @@ static int blkif_queue_rw_req(struct request *req)
*/
max_grefs += INDIRECT_GREFS(max_grefs);
- /* Check if we have enough grants to allocate a requests */
- if (info->persistent_gnts_c < max_grefs) {
- new_persistent_gnts = 1;
- if (gnttab_alloc_grant_references(
- max_grefs - info->persistent_gnts_c,
- &setup.gref_head) < 0) {
+ /*
+ * We have to reserve 'max_grefs' grants because persistent
+ * grants are shared by all rings.
+ */
+ if (max_grefs > 0)
+ if (gnttab_alloc_grant_references(max_grefs, &setup.gref_head) < 0) {
gnttab_request_free_callback(
- &info->callback,
+ &rinfo->callback,
blkif_restart_queue_callback,
- info,
+ rinfo,
max_grefs);
return 1;
}
- } else
- new_persistent_gnts = 0;
/* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
- id = get_id_from_freelist(info);
- info->shadow[id].request = req;
-
- BUG_ON(info->max_indirect_segments == 0 &&
- GREFS(req->nr_phys_segments) > BLKIF_MAX_SEGMENTS_PER_REQUEST);
- BUG_ON(info->max_indirect_segments &&
- GREFS(req->nr_phys_segments) > info->max_indirect_segments);
+ id = blkif_ring_get_request(rinfo, req, &ring_req);
- num_sg = blk_rq_map_sg(req->q, req, info->shadow[id].sg);
+ num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
num_grant = 0;
/* Calculate the number of grant used */
- for_each_sg(info->shadow[id].sg, sg, num_sg, i)
+ for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i)
num_grant += gnttab_count_grant(sg->offset, sg->length);
- ring_req->u.rw.id = id;
- info->shadow[id].num_sg = num_sg;
- if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
+ require_extra_req = info->max_indirect_segments == 0 &&
+ num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ BUG_ON(!HAS_EXTRA_REQ && require_extra_req);
+
+ rinfo->shadow[id].num_sg = num_sg;
+ if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST &&
+ likely(!require_extra_req)) {
/*
* The indirect operation can only be a BLKIF_OP_READ or
* BLKIF_OP_WRITE
@@ -670,11 +776,31 @@ static int blkif_queue_rw_req(struct request *req)
}
}
ring_req->u.rw.nr_segments = num_grant;
+ if (unlikely(require_extra_req)) {
+ extra_id = blkif_ring_get_request(rinfo, req,
+ &extra_ring_req);
+ /*
+ * Only the first request contains the scatter-gather
+ * list.
+ */
+ rinfo->shadow[extra_id].num_sg = 0;
+
+ blkif_setup_extra_req(ring_req, extra_ring_req);
+
+ /* Link the 2 requests together */
+ rinfo->shadow[extra_id].associated_id = id;
+ rinfo->shadow[id].associated_id = extra_id;
+ }
}
setup.ring_req = ring_req;
setup.id = id;
- for_each_sg(info->shadow[id].sg, sg, num_sg, i) {
+
+ setup.require_extra_req = require_extra_req;
+ if (unlikely(require_extra_req))
+ setup.extra_ring_req = extra_ring_req;
+
+ for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
if (setup.need_copy) {
@@ -694,12 +820,12 @@ static int blkif_queue_rw_req(struct request *req)
if (setup.segments)
kunmap_atomic(setup.segments);
- info->ring.req_prod_pvt++;
-
/* Keep a private copy so we can reissue requests when recovering. */
- info->shadow[id].req = *ring_req;
+ rinfo->shadow[id].req = *ring_req;
+ if (unlikely(require_extra_req))
+ rinfo->shadow[extra_id].req = *extra_ring_req;
- if (new_persistent_gnts)
+ if (max_grefs > 0)
gnttab_free_grant_references(setup.gref_head);
return 0;
@@ -711,27 +837,25 @@ static int blkif_queue_rw_req(struct request *req)
*
* @req: a request struct
*/
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_request(struct request *req, struct blkfront_ring_info *rinfo)
{
- struct blkfront_info *info = req->rq_disk->private_data;
-
- if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
+ if (unlikely(rinfo->dev_info->connected != BLKIF_STATE_CONNECTED))
return 1;
if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE)))
- return blkif_queue_discard_req(req);
+ return blkif_queue_discard_req(req, rinfo);
else
- return blkif_queue_rw_req(req);
+ return blkif_queue_rw_req(req, rinfo);
}
-static inline void flush_requests(struct blkfront_info *info)
+static inline void flush_requests(struct blkfront_ring_info *rinfo)
{
int notify;
- RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify);
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&rinfo->ring, notify);
if (notify)
- notify_remote_via_irq(info->irq);
+ notify_remote_via_irq(rinfo->irq);
}
static inline bool blkif_request_flush_invalid(struct request *req,
@@ -745,38 +869,50 @@ static inline bool blkif_request_flush_invalid(struct request *req,
}
static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
- const struct blk_mq_queue_data *qd)
+ const struct blk_mq_queue_data *qd)
{
- struct blkfront_info *info = qd->rq->rq_disk->private_data;
+ unsigned long flags;
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;
blk_mq_start_request(qd->rq);
- spin_lock_irq(&info->io_lock);
- if (RING_FULL(&info->ring))
+ spin_lock_irqsave(&rinfo->ring_lock, flags);
+ if (RING_FULL(&rinfo->ring))
goto out_busy;
- if (blkif_request_flush_invalid(qd->rq, info))
+ if (blkif_request_flush_invalid(qd->rq, rinfo->dev_info))
goto out_err;
- if (blkif_queue_request(qd->rq))
+ if (blkif_queue_request(qd->rq, rinfo))
goto out_busy;
- flush_requests(info);
- spin_unlock_irq(&info->io_lock);
+ flush_requests(rinfo);
+ spin_unlock_irqrestore(&rinfo->ring_lock, flags);
return BLK_MQ_RQ_QUEUE_OK;
out_err:
- spin_unlock_irq(&info->io_lock);
+ spin_unlock_irqrestore(&rinfo->ring_lock, flags);
return BLK_MQ_RQ_QUEUE_ERROR;
out_busy:
- spin_unlock_irq(&info->io_lock);
+ spin_unlock_irqrestore(&rinfo->ring_lock, flags);
blk_mq_stop_hw_queue(hctx);
return BLK_MQ_RQ_QUEUE_BUSY;
}
+static int blk_mq_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int index)
+{
+ struct blkfront_info *info = (struct blkfront_info *)data;
+
+ BUG_ON(info->nr_rings <= index);
+ hctx->driver_data = &info->rinfo[index];
+ return 0;
+}
+
static struct blk_mq_ops blkfront_mq_ops = {
.queue_rq = blkif_queue_rq,
.map_queue = blk_mq_map_queue,
+ .init_hctx = blk_mq_init_hctx,
};
static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
@@ -788,19 +924,28 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
memset(&info->tag_set, 0, sizeof(info->tag_set));
info->tag_set.ops = &blkfront_mq_ops;
- info->tag_set.nr_hw_queues = 1;
- info->tag_set.queue_depth = BLK_RING_SIZE(info);
+ info->tag_set.nr_hw_queues = info->nr_rings;
+ if (HAS_EXTRA_REQ && info->max_indirect_segments == 0) {
+ /*
+ * When indirect descriptior is not supported, the I/O request
+ * will be split between multiple request in the ring.
+ * To avoid problems when sending the request, divide by
+ * 2 the depth of the queue.
+ */
+ info->tag_set.queue_depth = BLK_RING_SIZE(info) / 2;
+ } else
+ info->tag_set.queue_depth = BLK_RING_SIZE(info);
info->tag_set.numa_node = NUMA_NO_NODE;
info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
info->tag_set.cmd_size = 0;
info->tag_set.driver_data = info;
if (blk_mq_alloc_tag_set(&info->tag_set))
- return -1;
+ return -EINVAL;
rq = blk_mq_init_queue(&info->tag_set);
if (IS_ERR(rq)) {
blk_mq_free_tag_set(&info->tag_set);
- return -1;
+ return PTR_ERR(rq);
}
queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
@@ -1028,7 +1173,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
static void xlvbd_release_gendisk(struct blkfront_info *info)
{
- unsigned int minor, nr_minors;
+ unsigned int minor, nr_minors, i;
if (info->rq == NULL)
return;
@@ -1036,11 +1181,15 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
/* No more blkif_request(). */
blk_mq_stop_hw_queues(info->rq);
- /* No more gnttab callback work. */
- gnttab_cancel_free_callback(&info->callback);
+ for (i = 0; i < info->nr_rings; i++) {
+ struct blkfront_ring_info *rinfo = &info->rinfo[i];
- /* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+ /* No more gnttab callback work. */
+ gnttab_cancel_free_callback(&rinfo->callback);
+
+ /* Flush gnttab callback work. Must be done with no locks held. */
+ flush_work(&rinfo->work);
+ }
del_gendisk(info->gd);
@@ -1056,88 +1205,87 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
info->gd = NULL;
}
-/* Must be called with io_lock holded */
-static void kick_pending_request_queues(struct blkfront_info *info)
+/* Already hold rinfo->ring_lock. */
+static inline void kick_pending_request_queues_locked(struct blkfront_ring_info *rinfo)
{
- if (!RING_FULL(&info->ring))
- blk_mq_start_stopped_hw_queues(info->rq, true);
+ if (!RING_FULL(&rinfo->ring))
+ blk_mq_start_stopped_hw_queues(rinfo->dev_info->rq, true);
}
-static void blkif_restart_queue(struct work_struct *work)
+static void kick_pending_request_queues(struct blkfront_ring_info *rinfo)
{
- struct blkfront_info *info = container_of(work, struct blkfront_info, work);
+ unsigned long flags;
- spin_lock_irq(&info->io_lock);
- if (info->connected == BLKIF_STATE_CONNECTED)
- kick_pending_request_queues(info);
- spin_unlock_irq(&info->io_lock);
+ spin_lock_irqsave(&rinfo->ring_lock, flags);
+ kick_pending_request_queues_locked(rinfo);
+ spin_unlock_irqrestore(&rinfo->ring_lock, flags);
}
-static void blkif_free(struct blkfront_info *info, int suspend)
+static void blkif_restart_queue(struct work_struct *work)
{
- struct grant *persistent_gnt;
- struct grant *n;
- int i, j, segs;
+ struct blkfront_ring_info *rinfo = container_of(work, struct blkfront_ring_info, work);
- /* Prevent new requests being issued until we fix things up. */
- spin_lock_irq(&info->io_lock);
- info->connected = suspend ?
- BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED;
- /* No more blkif_request(). */
- if (info->rq)
- blk_mq_stop_hw_queues(info->rq);
+ if (rinfo->dev_info->connected == BLKIF_STATE_CONNECTED)
+ kick_pending_request_queues(rinfo);
+}
- /* Remove all persistent grants */
- if (!list_empty(&info->grants)) {
- list_for_each_entry_safe(persistent_gnt, n,
- &info->grants, node) {
- list_del(&persistent_gnt->node);
- if (persistent_gnt->gref != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(persistent_gnt->gref,
- 0, 0UL);
- info->persistent_gnts_c--;
- }
- if (info->feature_persistent)
- __free_page(persistent_gnt->page);
- kfree(persistent_gnt);
- }
- }
- BUG_ON(info->persistent_gnts_c != 0);
+static void blkif_free_ring(struct blkfront_ring_info *rinfo)
+{
+ struct grant *persistent_gnt, *n;
+ struct blkfront_info *info = rinfo->dev_info;
+ int i, j, segs;
/*
* Remove indirect pages, this only happens when using indirect
* descriptors but not persistent grants
*/
- if (!list_empty(&info->indirect_pages)) {
+ if (!list_empty(&rinfo->indirect_pages)) {
struct page *indirect_page, *n;
BUG_ON(info->feature_persistent);
- list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+ list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
list_del(&indirect_page->lru);
__free_page(indirect_page);
}
}
+ /* Remove all persistent grants. */
+ if (!list_empty(&rinfo->grants)) {
+ list_for_each_entry_safe(persistent_gnt, n,
+ &rinfo->grants, node) {
+ list_del(&persistent_gnt->node);
+ if (persistent_gnt->gref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(persistent_gnt->gref,
+ 0, 0UL);
+ rinfo->persistent_gnts_c--;
+ }
+ if (info->feature_persistent)
+ __free_page(persistent_gnt->page);
+ kfree(persistent_gnt);
+ }
+ }
+ BUG_ON(rinfo->persistent_gnts_c != 0);
+
for (i = 0; i < BLK_RING_SIZE(info); i++) {
/*
* Clear persistent grants present in requests already
* on the shared ring
*/
- if (!info->shadow[i].request)
+ if (!rinfo->shadow[i].request)
goto free_shadow;
- segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
- info->shadow[i].req.u.indirect.nr_segments :
- info->shadow[i].req.u.rw.nr_segments;
+ segs = rinfo->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
+ rinfo->shadow[i].req.u.indirect.nr_segments :
+ rinfo->shadow[i].req.u.rw.nr_segments;
for (j = 0; j < segs; j++) {
- persistent_gnt = info->shadow[i].grants_used[j];
+ persistent_gnt = rinfo->shadow[i].grants_used[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
if (info->feature_persistent)
__free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
- if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT)
+ if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT)
/*
* If this is not an indirect operation don't try to
* free indirect segments
@@ -1145,42 +1293,59 @@ static void blkif_free(struct blkfront_info *info, int suspend)
goto free_shadow;
for (j = 0; j < INDIRECT_GREFS(segs); j++) {
- persistent_gnt = info->shadow[i].indirect_grants[j];
+ persistent_gnt = rinfo->shadow[i].indirect_grants[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
__free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
free_shadow:
- kfree(info->shadow[i].grants_used);
- info->shadow[i].grants_used = NULL;
- kfree(info->shadow[i].indirect_grants);
- info->shadow[i].indirect_grants = NULL;
- kfree(info->shadow[i].sg);
- info->shadow[i].sg = NULL;
+ kfree(rinfo->shadow[i].grants_used);
+ rinfo->shadow[i].grants_used = NULL;
+ kfree(rinfo->shadow[i].indirect_grants);
+ rinfo->shadow[i].indirect_grants = NULL;
+ kfree(rinfo->shadow[i].sg);
+ rinfo->shadow[i].sg = NULL;
}
/* No more gnttab callback work. */
- gnttab_cancel_free_callback(&info->callback);
- spin_unlock_irq(&info->io_lock);
+ gnttab_cancel_free_callback(&rinfo->callback);
/* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+ flush_work(&rinfo->work);
/* Free resources associated with old device channel. */
for (i = 0; i < info->nr_ring_pages; i++) {
- if (info->ring_ref[i] != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(info->ring_ref[i], 0, 0);
- info->ring_ref[i] = GRANT_INVALID_REF;
+ if (rinfo->ring_ref[i] != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(rinfo->ring_ref[i], 0, 0);
+ rinfo->ring_ref[i] = GRANT_INVALID_REF;
}
}
- free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
- info->ring.sring = NULL;
+ free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
+ rinfo->ring.sring = NULL;
- if (info->irq)
- unbind_from_irqhandler(info->irq, info);
- info->evtchn = info->irq = 0;
+ if (rinfo->irq)
+ unbind_from_irqhandler(rinfo->irq, rinfo);
+ rinfo->evtchn = rinfo->irq = 0;
+}
+static void blkif_free(struct blkfront_info *info, int suspend)
+{
+ unsigned int i;
+
+ /* Prevent new requests being issued until we fix things up. */
+ info->connected = suspend ?
+ BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED;
+ /* No more blkif_request(). */
+ if (info->rq)
+ blk_mq_stop_hw_queues(info->rq);
+
+ for (i = 0; i < info->nr_rings; i++)
+ blkif_free_ring(&info->rinfo[i]);
+
+ kfree(info->rinfo);
+ info->rinfo = NULL;
+ info->nr_rings = 0;
}
struct copy_from_grant {
@@ -1209,19 +1374,93 @@ static void blkif_copy_from_grant(unsigned long gfn, unsigned int offset,
kunmap_atomic(shared_data);
}
-static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
+static enum blk_req_status blkif_rsp_to_req_status(int rsp)
+{
+ switch (rsp)
+ {
+ case BLKIF_RSP_OKAY:
+ return REQ_DONE;
+ case BLKIF_RSP_EOPNOTSUPP:
+ return REQ_EOPNOTSUPP;
+ case BLKIF_RSP_ERROR:
+ /* Fallthrough. */
+ default:
+ return REQ_ERROR;
+ }
+}
+
+/*
+ * Get the final status of the block request based on two ring response
+ */
+static int blkif_get_final_status(enum blk_req_status s1,
+ enum blk_req_status s2)
+{
+ BUG_ON(s1 == REQ_WAITING);
+ BUG_ON(s2 == REQ_WAITING);
+
+ if (s1 == REQ_ERROR || s2 == REQ_ERROR)
+ return BLKIF_RSP_ERROR;
+ else if (s1 == REQ_EOPNOTSUPP || s2 == REQ_EOPNOTSUPP)
+ return BLKIF_RSP_EOPNOTSUPP;
+ return BLKIF_RSP_OKAY;
+}
+
+static bool blkif_completion(unsigned long *id,
+ struct blkfront_ring_info *rinfo,
struct blkif_response *bret)
{
int i = 0;
struct scatterlist *sg;
int num_sg, num_grant;
+ struct blkfront_info *info = rinfo->dev_info;
+ struct blk_shadow *s = &rinfo->shadow[*id];
struct copy_from_grant data = {
- .s = s,
.grant_idx = 0,
};
num_grant = s->req.operation == BLKIF_OP_INDIRECT ?
s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments;
+
+ /* The I/O request may be split in two. */
+ if (unlikely(s->associated_id != NO_ASSOCIATED_ID)) {
+ struct blk_shadow *s2 = &rinfo->shadow[s->associated_id];
+
+ /* Keep the status of the current response in shadow. */
+ s->status = blkif_rsp_to_req_status(bret->status);
+
+ /* Wait the second response if not yet here. */
+ if (s2->status == REQ_WAITING)
+ return 0;
+
+ bret->status = blkif_get_final_status(s->status,
+ s2->status);
+
+ /*
+ * All the grants is stored in the first shadow in order
+ * to make the completion code simpler.
+ */
+ num_grant += s2->req.u.rw.nr_segments;
+
+ /*
+ * The two responses may not come in order. Only the
+ * first request will store the scatter-gather list.
+ */
+ if (s2->num_sg != 0) {
+ /* Update "id" with the ID of the first response. */
+ *id = s->associated_id;
+ s = s2;
+ }
+
+ /*
+ * We don't need anymore the second request, so recycling
+ * it now.
+ */
+ if (add_id_to_freelist(rinfo, s->associated_id))
+ WARN(1, "%s: can't recycle the second part (id = %ld) of the request\n",
+ info->gd->disk_name, s->associated_id);
+ }
+
+ data.s = s;
num_sg = s->num_sg;
if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
@@ -1252,8 +1491,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
if (!info->feature_persistent)
pr_alert_ratelimited("backed has not unmapped grant: %u\n",
s->grants_used[i]->gref);
- list_add(&s->grants_used[i]->node, &info->grants);
- info->persistent_gnts_c++;
+ list_add(&s->grants_used[i]->node, &rinfo->grants);
+ rinfo->persistent_gnts_c++;
} else {
/*
* If the grant is not mapped by the backend we end the
@@ -1263,7 +1502,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
*/
gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL);
s->grants_used[i]->gref = GRANT_INVALID_REF;
- list_add_tail(&s->grants_used[i]->node, &info->grants);
+ list_add_tail(&s->grants_used[i]->node, &rinfo->grants);
}
}
if (s->req.operation == BLKIF_OP_INDIRECT) {
@@ -1272,8 +1511,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
if (!info->feature_persistent)
pr_alert_ratelimited("backed has not unmapped grant: %u\n",
s->indirect_grants[i]->gref);
- list_add(&s->indirect_grants[i]->node, &info->grants);
- info->persistent_gnts_c++;
+ list_add(&s->indirect_grants[i]->node, &rinfo->grants);
+ rinfo->persistent_gnts_c++;
} else {
struct page *indirect_page;
@@ -1284,13 +1523,15 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
*/
if (!info->feature_persistent) {
indirect_page = s->indirect_grants[i]->page;
- list_add(&indirect_page->lru, &info->indirect_pages);
+ list_add(&indirect_page->lru, &rinfo->indirect_pages);
}
s->indirect_grants[i]->gref = GRANT_INVALID_REF;
- list_add_tail(&s->indirect_grants[i]->node, &info->grants);
+ list_add_tail(&s->indirect_grants[i]->node, &rinfo->grants);
}
}
}
+
+ return 1;
}
static irqreturn_t blkif_interrupt(int irq, void *dev_id)
@@ -1299,24 +1540,22 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
struct blkif_response *bret;
RING_IDX i, rp;
unsigned long flags;
- struct blkfront_info *info = (struct blkfront_info *)dev_id;
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
+ struct blkfront_info *info = rinfo->dev_info;
int error;
- spin_lock_irqsave(&info->io_lock, flags);
-
- if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) {
- spin_unlock_irqrestore(&info->io_lock, flags);
+ if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
return IRQ_HANDLED;
- }
+ spin_lock_irqsave(&rinfo->ring_lock, flags);
again:
- rp = info->ring.sring->rsp_prod;
+ rp = rinfo->ring.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
- for (i = info->ring.rsp_cons; i != rp; i++) {
+ for (i = rinfo->ring.rsp_cons; i != rp; i++) {
unsigned long id;
- bret = RING_GET_RESPONSE(&info->ring, i);
+ bret = RING_GET_RESPONSE(&rinfo->ring, i);
id = bret->id;
/*
* The backend has messed up and given us an id that we would
@@ -1330,12 +1569,18 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
* the id is busted. */
continue;
}
- req = info->shadow[id].request;
+ req = rinfo->shadow[id].request;
- if (bret->operation != BLKIF_OP_DISCARD)
- blkif_completion(&info->shadow[id], info, bret);
+ if (bret->operation != BLKIF_OP_DISCARD) {
+ /*
+ * We may need to wait for an extra response if the
+ * I/O request is split in 2
+ */
+ if (!blkif_completion(&id, rinfo, bret))
+ continue;
+ }
- if (add_id_to_freelist(info, id)) {
+ if (add_id_to_freelist(rinfo, id)) {
WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n",
info->gd->disk_name, op_name(bret->operation), id);
continue;
@@ -1364,7 +1609,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
error = -EOPNOTSUPP;
}
if (unlikely(bret->status == BLKIF_RSP_ERROR &&
- info->shadow[id].req.u.rw.nr_segments == 0)) {
+ rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
info->gd->disk_name, op_name(bret->operation));
error = -EOPNOTSUPP;
@@ -1389,34 +1634,35 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
}
}
- info->ring.rsp_cons = i;
+ rinfo->ring.rsp_cons = i;
- if (i != info->ring.req_prod_pvt) {
+ if (i != rinfo->ring.req_prod_pvt) {
int more_to_do;
- RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do);
+ RING_FINAL_CHECK_FOR_RESPONSES(&rinfo->ring, more_to_do);
if (more_to_do)
goto again;
} else
- info->ring.sring->rsp_event = i + 1;
+ rinfo->ring.sring->rsp_event = i + 1;
- kick_pending_request_queues(info);
+ kick_pending_request_queues_locked(rinfo);
- spin_unlock_irqrestore(&info->io_lock, flags);
+ spin_unlock_irqrestore(&rinfo->ring_lock, flags);
return IRQ_HANDLED;
}
static int setup_blkring(struct xenbus_device *dev,
- struct blkfront_info *info)
+ struct blkfront_ring_info *rinfo)
{
struct blkif_sring *sring;
int err, i;
+ struct blkfront_info *info = rinfo->dev_info;
unsigned long ring_size = info->nr_ring_pages * XEN_PAGE_SIZE;
grant_ref_t gref[XENBUS_MAX_RING_GRANTS];
for (i = 0; i < info->nr_ring_pages; i++)
- info->ring_ref[i] = GRANT_INVALID_REF;
+ rinfo->ring_ref[i] = GRANT_INVALID_REF;
sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
get_order(ring_size));
@@ -1425,29 +1671,29 @@ static int setup_blkring(struct xenbus_device *dev,
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, ring_size);
+ FRONT_RING_INIT(&rinfo->ring, sring, ring_size);
- err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref);
+ err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
if (err < 0) {
free_pages((unsigned long)sring, get_order(ring_size));
- info->ring.sring = NULL;
+ rinfo->ring.sring = NULL;
goto fail;
}
for (i = 0; i < info->nr_ring_pages; i++)
- info->ring_ref[i] = gref[i];
+ rinfo->ring_ref[i] = gref[i];
- err = xenbus_alloc_evtchn(dev, &info->evtchn);
+ err = xenbus_alloc_evtchn(dev, &rinfo->evtchn);
if (err)
goto fail;
- err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0,
- "blkif", info);
+ err = bind_evtchn_to_irqhandler(rinfo->evtchn, blkif_interrupt, 0,
+ "blkif", rinfo);
if (err <= 0) {
xenbus_dev_fatal(dev, err,
"bind_evtchn_to_irqhandler failed");
goto fail;
}
- info->irq = err;
+ rinfo->irq = err;
return 0;
fail:
@@ -1455,6 +1701,53 @@ fail:
return err;
}
+/*
+ * Write out per-ring/queue nodes including ring-ref and event-channel, and each
+ * ring buffer may have multi pages depending on ->nr_ring_pages.
+ */
+static int write_per_ring_nodes(struct xenbus_transaction xbt,
+ struct blkfront_ring_info *rinfo, const char *dir)
+{
+ int err;
+ unsigned int i;
+ const char *message = NULL;
+ struct blkfront_info *info = rinfo->dev_info;
+
+ if (info->nr_ring_pages == 1) {
+ err = xenbus_printf(xbt, dir, "ring-ref", "%u", rinfo->ring_ref[0]);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ } else {
+ for (i = 0; i < info->nr_ring_pages; i++) {
+ char ring_ref_name[RINGREF_NAME_LEN];
+
+ snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
+ err = xenbus_printf(xbt, dir, ring_ref_name,
+ "%u", rinfo->ring_ref[i]);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ }
+ }
+
+ err = xenbus_printf(xbt, dir, "event-channel", "%u", rinfo->evtchn);
+ if (err) {
+ message = "writing event-channel";
+ goto abort_transaction;
+ }
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ if (message)
+ xenbus_dev_fatal(info->xbdev, err, "%s", message);
+
+ return err;
+}
/* Common code used when first setting up, and when resuming. */
static int talk_to_blkback(struct xenbus_device *dev,
@@ -1462,8 +1755,8 @@ static int talk_to_blkback(struct xenbus_device *dev,
{
const char *message = NULL;
struct xenbus_transaction xbt;
- int err, i;
- unsigned int max_page_order = 0;
+ int err;
+ unsigned int i, max_page_order = 0;
unsigned int ring_page_order = 0;
err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
@@ -1475,10 +1768,14 @@ static int talk_to_blkback(struct xenbus_device *dev,
info->nr_ring_pages = 1 << ring_page_order;
}
- /* Create shared ring, alloc event channel. */
- err = setup_blkring(dev, info);
- if (err)
- goto out;
+ for (i = 0; i < info->nr_rings; i++) {
+ struct blkfront_ring_info *rinfo = &info->rinfo[i];
+
+ /* Create shared ring, alloc event channel. */
+ err = setup_blkring(dev, rinfo);
+ if (err)
+ goto destroy_blkring;
+ }
again:
err = xenbus_transaction_start(&xbt);
@@ -1487,38 +1784,49 @@ again:
goto destroy_blkring;
}
- if (info->nr_ring_pages == 1) {
- err = xenbus_printf(xbt, dev->nodename,
- "ring-ref", "%u", info->ring_ref[0]);
+ if (info->nr_ring_pages > 1) {
+ err = xenbus_printf(xbt, dev->nodename, "ring-page-order", "%u",
+ ring_page_order);
if (err) {
- message = "writing ring-ref";
+ message = "writing ring-page-order";
goto abort_transaction;
}
+ }
+
+ /* We already got the number of queues/rings in _probe */
+ if (info->nr_rings == 1) {
+ err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename);
+ if (err)
+ goto destroy_blkring;
} else {
- err = xenbus_printf(xbt, dev->nodename,
- "ring-page-order", "%u", ring_page_order);
+ char *path;
+ size_t pathsize;
+
+ err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", "%u",
+ info->nr_rings);
if (err) {
- message = "writing ring-page-order";
+ message = "writing multi-queue-num-queues";
goto abort_transaction;
}
- for (i = 0; i < info->nr_ring_pages; i++) {
- char ring_ref_name[RINGREF_NAME_LEN];
+ pathsize = strlen(dev->nodename) + QUEUE_NAME_LEN;
+ path = kmalloc(pathsize, GFP_KERNEL);
+ if (!path) {
+ err = -ENOMEM;
+ message = "ENOMEM while writing ring references";
+ goto abort_transaction;
+ }
- snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
- err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
- "%u", info->ring_ref[i]);
+ for (i = 0; i < info->nr_rings; i++) {
+ memset(path, 0, pathsize);
+ snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i);
+ err = write_per_ring_nodes(xbt, &info->rinfo[i], path);
if (err) {
- message = "writing ring-ref";
- goto abort_transaction;
+ kfree(path);
+ goto destroy_blkring;
}
}
- }
- err = xenbus_printf(xbt, dev->nodename,
- "event-channel", "%u", info->evtchn);
- if (err) {
- message = "writing event-channel";
- goto abort_transaction;
+ kfree(path);
}
err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
XEN_IO_PROTO_ABI_NATIVE);
@@ -1540,9 +1848,14 @@ again:
goto destroy_blkring;
}
- for (i = 0; i < BLK_RING_SIZE(info); i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+ for (i = 0; i < info->nr_rings; i++) {
+ unsigned int j;
+ struct blkfront_ring_info *rinfo = &info->rinfo[i];
+
+ for (j = 0; j < BLK_RING_SIZE(info); j++)
+ rinfo->shadow[j].req.u.rw.id = j + 1;
+ rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+ }
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
@@ -1553,7 +1866,10 @@ again:
xenbus_dev_fatal(dev, err, "%s", message);
destroy_blkring:
blkif_free(info, 0);
- out:
+
+ kfree(info);
+ dev_set_drvdata(&dev->dev, NULL);
+
return err;
}
@@ -1567,7 +1883,9 @@ static int blkfront_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int err, vdevice;
+ unsigned int r_index;
struct blkfront_info *info;
+ unsigned int backend_max_queues = 0;
/* FIXME: Use dynamic device id if this is not set. */
err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1617,15 +1935,39 @@ static int blkfront_probe(struct xenbus_device *dev,
return -ENOMEM;
}
- mutex_init(&info->mutex);
- spin_lock_init(&info->io_lock);
info->xbdev = dev;
+ /* Check if backend supports multiple queues. */
+ err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+ "multi-queue-max-queues", "%u", &backend_max_queues);
+ if (err < 0)
+ backend_max_queues = 1;
+
+ info->nr_rings = min(backend_max_queues, xen_blkif_max_queues);
+ /* We need at least one ring. */
+ if (!info->nr_rings)
+ info->nr_rings = 1;
+
+ info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL);
+ if (!info->rinfo) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating ring_info structure");
+ kfree(info);
+ return -ENOMEM;
+ }
+
+ for (r_index = 0; r_index < info->nr_rings; r_index++) {
+ struct blkfront_ring_info *rinfo;
+
+ rinfo = &info->rinfo[r_index];
+ INIT_LIST_HEAD(&rinfo->indirect_pages);
+ INIT_LIST_HEAD(&rinfo->grants);
+ rinfo->dev_info = info;
+ INIT_WORK(&rinfo->work, blkif_restart_queue);
+ spin_lock_init(&rinfo->ring_lock);
+ }
+
+ mutex_init(&info->mutex);
info->vdevice = vdevice;
- INIT_LIST_HEAD(&info->grants);
- INIT_LIST_HEAD(&info->indirect_pages);
- info->persistent_gnts_c = 0;
info->connected = BLKIF_STATE_DISCONNECTED;
- INIT_WORK(&info->work, blkif_restart_queue);
/* Front end dir is a number, which is used as the id. */
info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
@@ -1649,7 +1991,7 @@ static void split_bio_end(struct bio *bio)
static int blkif_recover(struct blkfront_info *info)
{
- int i;
+ unsigned int i, r_index;
struct request *req, *n;
struct blk_shadow *copy;
int rc;
@@ -1660,64 +2002,73 @@ static int blkif_recover(struct blkfront_info *info)
struct split_bio *split_bio;
struct list_head requests;
- /* Stage 1: Make a safe copy of the shadow state. */
- copy = kmemdup(info->shadow, sizeof(info->shadow),
- GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
- if (!copy)
- return -ENOMEM;
-
- /* Stage 2: Set up free list. */
- memset(&info->shadow, 0, sizeof(info->shadow));
- for (i = 0; i < BLK_RING_SIZE(info); i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow_free = info->ring.req_prod_pvt;
- info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
-
- rc = blkfront_gather_backend_features(info);
- if (rc) {
- kfree(copy);
- return rc;
- }
-
+ blkfront_gather_backend_features(info);
segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
blk_queue_max_segments(info->rq, segs);
bio_list_init(&bio_list);
INIT_LIST_HEAD(&requests);
- for (i = 0; i < BLK_RING_SIZE(info); i++) {
- /* Not in use? */
- if (!copy[i].request)
- continue;
- /*
- * Get the bios in the request so we can re-queue them.
- */
- if (copy[i].request->cmd_flags &
- (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
+ for (r_index = 0; r_index < info->nr_rings; r_index++) {
+ struct blkfront_ring_info *rinfo;
+
+ rinfo = &info->rinfo[r_index];
+ /* Stage 1: Make a safe copy of the shadow state. */
+ copy = kmemdup(rinfo->shadow, sizeof(rinfo->shadow),
+ GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
+ if (!copy)
+ return -ENOMEM;
+
+ /* Stage 2: Set up free list. */
+ memset(&rinfo->shadow, 0, sizeof(rinfo->shadow));
+ for (i = 0; i < BLK_RING_SIZE(info); i++)
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->shadow_free = rinfo->ring.req_prod_pvt;
+ rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+
+ rc = blkfront_setup_indirect(rinfo);
+ if (rc) {
+ kfree(copy);
+ return rc;
+ }
+
+ for (i = 0; i < BLK_RING_SIZE(info); i++) {
+ /* Not in use? */
+ if (!copy[i].request)
+ continue;
+
/*
- * Flush operations don't contain bios, so
- * we need to requeue the whole request
+ * Get the bios in the request so we can re-queue them.
*/
- list_add(&copy[i].request->queuelist, &requests);
- continue;
+ if (copy[i].request->cmd_flags &
+ (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
+ /*
+ * Flush operations don't contain bios, so
+ * we need to requeue the whole request
+ */
+ list_add(&copy[i].request->queuelist, &requests);
+ continue;
+ }
+ merge_bio.head = copy[i].request->bio;
+ merge_bio.tail = copy[i].request->biotail;
+ bio_list_merge(&bio_list, &merge_bio);
+ copy[i].request->bio = NULL;
+ blk_end_request_all(copy[i].request, 0);
}
- merge_bio.head = copy[i].request->bio;
- merge_bio.tail = copy[i].request->biotail;
- bio_list_merge(&bio_list, &merge_bio);
- copy[i].request->bio = NULL;
- blk_end_request_all(copy[i].request, 0);
- }
-
- kfree(copy);
+ kfree(copy);
+ }
xenbus_switch_state(info->xbdev, XenbusStateConnected);
- spin_lock_irq(&info->io_lock);
-
/* Now safe for us to use the shared ring */
info->connected = BLKIF_STATE_CONNECTED;
- /* Kick any other new requests queued since we resumed */
- kick_pending_request_queues(info);
+ for (r_index = 0; r_index < info->nr_rings; r_index++) {
+ struct blkfront_ring_info *rinfo;
+
+ rinfo = &info->rinfo[r_index];
+ /* Kick any other new requests queued since we resumed */
+ kick_pending_request_queues(rinfo);
+ }
list_for_each_entry_safe(req, n, &requests, queuelist) {
/* Requeue pending requests (flush or discard) */
@@ -1725,7 +2076,6 @@ static int blkif_recover(struct blkfront_info *info)
BUG_ON(req->nr_phys_segments > segs);
blk_mq_requeue_request(req);
}
- spin_unlock_irq(&info->io_lock);
blk_mq_kick_requeue_list(info->rq);
while ((bio = bio_list_pop(&bio_list)) != NULL) {
@@ -1790,8 +2140,7 @@ static int blkfront_resume(struct xenbus_device *dev)
return err;
}
-static void
-blkfront_closing(struct blkfront_info *info)
+static void blkfront_closing(struct blkfront_info *info)
{
struct xenbus_device *xbdev = info->xbdev;
struct block_device *bdev = NULL;
@@ -1851,18 +2200,29 @@ static void blkfront_setup_discard(struct blkfront_info *info)
info->feature_secdiscard = !!discard_secure;
}
-static int blkfront_setup_indirect(struct blkfront_info *info)
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
{
unsigned int psegs, grants;
int err, i;
+ struct blkfront_info *info = rinfo->dev_info;
- if (info->max_indirect_segments == 0)
- grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ if (info->max_indirect_segments == 0) {
+ if (!HAS_EXTRA_REQ)
+ grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ else {
+ /*
+ * When an extra req is required, the maximum
+ * grants supported is related to the size of the
+ * Linux block segment.
+ */
+ grants = GRANTS_PER_PSEG;
+ }
+ }
else
grants = info->max_indirect_segments;
psegs = grants / GRANTS_PER_PSEG;
- err = fill_grant_buffer(info,
+ err = fill_grant_buffer(rinfo,
(grants + INDIRECT_GREFS(grants)) * BLK_RING_SIZE(info));
if (err)
goto out_of_memory;
@@ -1875,31 +2235,31 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
*/
int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info);
- BUG_ON(!list_empty(&info->indirect_pages));
+ BUG_ON(!list_empty(&rinfo->indirect_pages));
for (i = 0; i < num; i++) {
struct page *indirect_page = alloc_page(GFP_NOIO);
if (!indirect_page)
goto out_of_memory;
- list_add(&indirect_page->lru, &info->indirect_pages);
+ list_add(&indirect_page->lru, &rinfo->indirect_pages);
}
}
for (i = 0; i < BLK_RING_SIZE(info); i++) {
- info->shadow[i].grants_used = kzalloc(
- sizeof(info->shadow[i].grants_used[0]) * grants,
+ rinfo->shadow[i].grants_used = kzalloc(
+ sizeof(rinfo->shadow[i].grants_used[0]) * grants,
GFP_NOIO);
- info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * psegs, GFP_NOIO);
+ rinfo->shadow[i].sg = kzalloc(sizeof(rinfo->shadow[i].sg[0]) * psegs, GFP_NOIO);
if (info->max_indirect_segments)
- info->shadow[i].indirect_grants = kzalloc(
- sizeof(info->shadow[i].indirect_grants[0]) *
+ rinfo->shadow[i].indirect_grants = kzalloc(
+ sizeof(rinfo->shadow[i].indirect_grants[0]) *
INDIRECT_GREFS(grants),
GFP_NOIO);
- if ((info->shadow[i].grants_used == NULL) ||
- (info->shadow[i].sg == NULL) ||
+ if ((rinfo->shadow[i].grants_used == NULL) ||
+ (rinfo->shadow[i].sg == NULL) ||
(info->max_indirect_segments &&
- (info->shadow[i].indirect_grants == NULL)))
+ (rinfo->shadow[i].indirect_grants == NULL)))
goto out_of_memory;
- sg_init_table(info->shadow[i].sg, psegs);
+ sg_init_table(rinfo->shadow[i].sg, psegs);
}
@@ -1907,16 +2267,16 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
out_of_memory:
for (i = 0; i < BLK_RING_SIZE(info); i++) {
- kfree(info->shadow[i].grants_used);
- info->shadow[i].grants_used = NULL;
- kfree(info->shadow[i].sg);
- info->shadow[i].sg = NULL;
- kfree(info->shadow[i].indirect_grants);
- info->shadow[i].indirect_grants = NULL;
- }
- if (!list_empty(&info->indirect_pages)) {
+ kfree(rinfo->shadow[i].grants_used);
+ rinfo->shadow[i].grants_used = NULL;
+ kfree(rinfo->shadow[i].sg);
+ rinfo->shadow[i].sg = NULL;
+ kfree(rinfo->shadow[i].indirect_grants);
+ rinfo->shadow[i].indirect_grants = NULL;
+ }
+ if (!list_empty(&rinfo->indirect_pages)) {
struct page *indirect_page, *n;
- list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+ list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
list_del(&indirect_page->lru);
__free_page(indirect_page);
}
@@ -1927,7 +2287,7 @@ out_of_memory:
/*
* Gather all backend feature-*
*/
-static int blkfront_gather_backend_features(struct blkfront_info *info)
+static void blkfront_gather_backend_features(struct blkfront_info *info)
{
int err;
int barrier, flush, discard, persistent;
@@ -1982,8 +2342,6 @@ static int blkfront_gather_backend_features(struct blkfront_info *info)
else
info->max_indirect_segments = min(indirect_segments,
xen_blkif_max_segments);
-
- return blkfront_setup_indirect(info);
}
/*
@@ -1996,7 +2354,7 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned long sector_size;
unsigned int physical_sector_size;
unsigned int binfo;
- int err;
+ int err, i;
switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -2053,11 +2411,15 @@ static void blkfront_connect(struct blkfront_info *info)
if (err != 1)
physical_sector_size = sector_size;
- err = blkfront_gather_backend_features(info);
- if (err) {
- xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
- info->xbdev->otherend);
- return;
+ blkfront_gather_backend_features(info);
+ for (i = 0; i < info->nr_rings; i++) {
+ err = blkfront_setup_indirect(&info->rinfo[i]);
+ if (err) {
+ xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
+ info->xbdev->otherend);
+ blkif_free(info, 0);
+ break;
+ }
}
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size,
@@ -2071,10 +2433,9 @@ static void blkfront_connect(struct blkfront_info *info)
xenbus_switch_state(info->xbdev, XenbusStateConnected);
/* Kick pending requests. */
- spin_lock_irq(&info->io_lock);
info->connected = BLKIF_STATE_CONNECTED;
- kick_pending_request_queues(info);
- spin_unlock_irq(&info->io_lock);
+ for (i = 0; i < info->nr_rings; i++)
+ kick_pending_request_queues(&info->rinfo[i]);
add_disk(info->gd);
@@ -2095,11 +2456,8 @@ static void blkback_changed(struct xenbus_device *dev,
case XenbusStateInitWait:
if (dev->state != XenbusStateInitialising)
break;
- if (talk_to_blkback(dev, info)) {
- kfree(info);
- dev_set_drvdata(&dev->dev, NULL);
+ if (talk_to_blkback(dev, info))
break;
- }
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
@@ -2108,6 +2466,10 @@ static void blkback_changed(struct xenbus_device *dev,
break;
case XenbusStateConnected:
+ if (dev->state != XenbusStateInitialised) {
+ if (talk_to_blkback(dev, info))
+ break;
+ }
blkfront_connect(info);
break;
@@ -2281,6 +2643,7 @@ static struct xenbus_driver blkfront_driver = {
static int __init xlblk_init(void)
{
int ret;
+ int nr_cpus = num_online_cpus();
if (!xen_domain())
return -ENODEV;
@@ -2288,7 +2651,13 @@ static int __init xlblk_init(void)
if (xen_blkif_max_ring_order > XENBUS_MAX_RING_GRANT_ORDER) {
pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
xen_blkif_max_ring_order, XENBUS_MAX_RING_GRANT_ORDER);
- xen_blkif_max_ring_order = 0;
+ xen_blkif_max_ring_order = XENBUS_MAX_RING_GRANT_ORDER;
+ }
+
+ if (xen_blkif_max_queues > nr_cpus) {
+ pr_info("Invalid max_queues (%d), will use default max: %d.\n",
+ xen_blkif_max_queues, nr_cpus);
+ xen_blkif_max_queues = nr_cpus;
}
if (!xen_has_pv_disk_devices())