* [PATCH RFC 3/4] xen, blkfront: introduce support for multiple hw queues
2014-08-22 11:20 [PATCH RFC 0/4] Multi-queue support for xen-blkfront and xen-blkback Arianna Avanzini
2014-08-22 11:20 ` [PATCH RFC 1/4] xen, blkfront: add support for the multi-queue block layer API Arianna Avanzini
2014-08-22 11:20 ` [PATCH RFC 2/4] xen, blkfront: factor out flush-related checks from do_blkif_request() Arianna Avanzini
@ 2014-08-22 11:20 ` Arianna Avanzini
2014-08-22 12:52 ` David Vrabel
2014-08-22 11:20 ` [PATCH RFC 4/4] xen, blkback: add support for multiple block rings Arianna Avanzini
2014-09-15 9:23 ` [Xen-devel] [PATCH RFC 0/4] Multi-queue support for xen-blkfront and xen-blkback Roger Pau Monné
4 siblings, 1 reply; 18+ messages in thread
From: Arianna Avanzini @ 2014-08-22 11:20 UTC (permalink / raw)
To: konrad.wilk, boris.ostrovsky, david.vrabel, xen-devel, linux-kernel
Cc: bob.liu, felipe.franciosi, axboe, avanzini.arianna
This commit introduces in xen-blkfront actual support for multiple
hardware queues. The number of available hardware queues is gathered
from the backend via XenStore; in case the expected XenStore key
is not available, the frontend defaults to a single I/O ring.
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
---
drivers/block/xen-blkfront.c | 793 +++++++++++++++++++++++++------------------
1 file changed, 463 insertions(+), 330 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index a047346..e27aaa1 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -99,10 +99,27 @@ 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 hardware_queues = 1;
-
#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
+struct blkfront_ring_info
+{
+ spinlock_t io_lock;
+ int ring_ref;
+ struct blkif_front_ring ring;
+ unsigned int evtchn, irq;
+ struct blk_shadow shadow[BLK_RING_SIZE];
+ unsigned long shadow_free;
+
+ struct work_struct work;
+ struct gnttab_free_callback callback;
+ struct list_head grants;
+ struct list_head indirect_pages;
+ unsigned int persistent_gnts_c;
+
+ struct blkfront_info *info;
+ unsigned int hctx_index;
+};
+
/*
* We have one of these per vbd, whether ide, scsi or 'other'. They
* hang in private_data off the gendisk structure. We may end up
@@ -110,24 +127,15 @@ static unsigned int hardware_queues = 1;
*/
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;
- struct blkif_front_ring ring;
- unsigned int evtchn, irq;
+ unsigned int nr_rings;
+ struct blkfront_ring_info *rinfo;
struct request_queue *rq;
- struct work_struct work;
- struct gnttab_free_callback callback;
- struct blk_shadow shadow[BLK_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 flush_op;
unsigned int feature_discard:1;
@@ -135,6 +143,7 @@ struct blkfront_info
unsigned int discard_granularity;
unsigned int discard_alignment;
unsigned int feature_persistent:1;
+ unsigned int hardware_queues;
unsigned int max_indirect_segments;
int is_ready;
/* Block layer tags. */
@@ -171,32 +180,35 @@ static DEFINE_SPINLOCK(minor_lock);
#define INDIRECT_GREFS(_segs) \
((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
-static int blkfront_setup_indirect(struct blkfront_info *info);
+static int blkfront_gather_indirect(struct blkfront_info *info);
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo,
+ unsigned int segs);
-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;
+ unsigned long free = rinfo->shadow_free;
BUG_ON(free >= BLK_RING_SIZE);
- info->shadow_free = info->shadow[free].req.u.rw.id;
- info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
+ 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,
+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->info;
struct page *granted_page;
struct grant *gnt_list_entry, *n;
int i = 0;
@@ -216,7 +228,7 @@ 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++;
}
@@ -224,7 +236,7 @@ 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(pfn_to_page(gnt_list_entry->pfn));
@@ -237,31 +249,31 @@ out_of_memory:
static struct grant *get_grant(grant_ref_t *gref_head,
unsigned long pfn,
- struct blkfront_info *info)
+ struct blkfront_ring_info *rinfo)
{
struct grant *gnt_list_entry;
unsigned long buffer_mfn;
- 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;
}
/* Assign a gref to this page */
gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head);
BUG_ON(gnt_list_entry->gref == -ENOSPC);
- if (!info->feature_persistent) {
+ if (!rinfo->info->feature_persistent) {
BUG_ON(!pfn);
gnt_list_entry->pfn = pfn;
}
buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn);
gnttab_grant_foreign_access_ref(gnt_list_entry->gref,
- info->xbdev->otherend_id,
+ rinfo->info->xbdev->otherend_id,
buffer_mfn, 0);
return gnt_list_entry;
}
@@ -332,8 +344,8 @@ 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)
@@ -392,9 +404,11 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
* @req: a request struct
* @ring_idx: index of the ring the request is to be inserted in
*/
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_request(struct request *req, unsigned int ring_idx)
{
struct blkfront_info *info = req->rq_disk->private_data;
+ struct blkfront_ring_info *rinfo = &info->rinfo[ring_idx];
+ struct blkif_front_ring *ring = &info->rinfo[ring_idx].ring;
struct blkif_request *ring_req;
unsigned long id;
unsigned int fsect, lsect;
@@ -424,15 +438,15 @@ static int blkif_queue_request(struct request *req)
max_grefs += INDIRECT_GREFS(req->nr_phys_segments);
/* Check if we have enough grants to allocate a requests */
- if (info->persistent_gnts_c < max_grefs) {
+ if (rinfo->persistent_gnts_c < max_grefs) {
new_persistent_gnts = 1;
if (gnttab_alloc_grant_references(
- max_grefs - info->persistent_gnts_c,
+ max_grefs - rinfo->persistent_gnts_c,
&gref_head) < 0) {
gnttab_request_free_callback(
- &info->callback,
+ &rinfo->callback,
blkif_restart_queue_callback,
- info,
+ rinfo,
max_grefs);
return 1;
}
@@ -440,9 +454,9 @@ static int blkif_queue_request(struct request *req)
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;
+ ring_req = RING_GET_REQUEST(ring, ring->req_prod_pvt);
+ id = get_id_from_freelist(rinfo);
+ rinfo->shadow[id].request = req;
if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) {
ring_req->operation = BLKIF_OP_DISCARD;
@@ -458,7 +472,7 @@ static int blkif_queue_request(struct request *req)
req->nr_phys_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
BUG_ON(info->max_indirect_segments &&
req->nr_phys_segments > info->max_indirect_segments);
- nseg = blk_rq_map_sg(req->q, req, info->shadow[id].sg);
+ nseg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
ring_req->u.rw.id = id;
if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
/*
@@ -489,7 +503,7 @@ static int blkif_queue_request(struct request *req)
}
ring_req->u.rw.nr_segments = nseg;
}
- for_each_sg(info->shadow[id].sg, sg, nseg, i) {
+ for_each_sg(rinfo->shadow[id].sg, sg, nseg, i) {
fsect = sg->offset >> 9;
lsect = fsect + (sg->length >> 9) - 1;
@@ -505,22 +519,22 @@ static int blkif_queue_request(struct request *req)
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);
pfn = page_to_pfn(indirect_page);
}
- gnt_list_entry = get_grant(&gref_head, pfn, info);
- info->shadow[id].indirect_grants[n] = gnt_list_entry;
+ gnt_list_entry = get_grant(&gref_head, pfn, rinfo);
+ rinfo->shadow[id].indirect_grants[n] = gnt_list_entry;
segments = kmap_atomic(pfn_to_page(gnt_list_entry->pfn));
ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref;
}
- gnt_list_entry = get_grant(&gref_head, page_to_pfn(sg_page(sg)), info);
+ gnt_list_entry = get_grant(&gref_head, page_to_pfn(sg_page(sg)), rinfo);
ref = gnt_list_entry->gref;
- info->shadow[id].grants_used[i] = gnt_list_entry;
+ rinfo->shadow[id].grants_used[i] = gnt_list_entry;
if (rq_data_dir(req) && info->feature_persistent) {
char *bvec_data;
@@ -566,10 +580,10 @@ static int blkif_queue_request(struct request *req)
kunmap_atomic(segments);
}
- info->ring.req_prod_pvt++;
+ 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 (new_persistent_gnts)
gnttab_free_grant_references(gref_head);
@@ -578,14 +592,16 @@ static int blkif_queue_request(struct request *req)
}
-static inline void flush_requests(struct blkfront_info *info)
+static inline void flush_requests(struct blkfront_info *info,
+ unsigned int ring_idx)
{
+ struct blkfront_ring_info *rinfo = &info->rinfo[ring_idx];
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_mismatch(struct request *req,
@@ -612,8 +628,9 @@ static void do_blkif_request(struct request_queue *rq)
while ((req = blk_peek_request(rq)) != NULL) {
info = req->rq_disk->private_data;
+ BUG_ON(info->nr_rings != 1);
- if (RING_FULL(&info->ring))
+ if (RING_FULL(&info->rinfo[0].ring))
goto wait;
blk_start_request(req);
@@ -629,7 +646,7 @@ static void do_blkif_request(struct request_queue *rq)
blk_rq_cur_sectors(req), blk_rq_sectors(req),
rq_data_dir(req) ? "write" : "read");
- if (blkif_queue_request(req)) {
+ if (blkif_queue_request(req, 0)) {
blk_requeue_request(rq, req);
wait:
/* Avoid pointless unplugs. */
@@ -641,23 +658,25 @@ wait:
}
if (queued != 0)
- flush_requests(info);
+ flush_requests(info, 0);
}
static int blkfront_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
{
- struct blkfront_info *info = req->rq_disk->private_data;
+ struct blkfront_ring_info *rinfo =
+ (struct blkfront_ring_info *)hctx->driver_data;
+ struct blkfront_info *info = rinfo->info;
pr_debug("Entered blkfront_queue_rq\n");
- spin_lock_irq(&info->io_lock);
- if (RING_FULL(&info->ring))
+ spin_lock_irq(&rinfo->io_lock);
+ if (RING_FULL(&rinfo->ring))
goto wait;
if (blkif_request_flush_mismatch(req, info)) {
req->errors = -EIO;
blk_mq_complete_request(req);
- spin_unlock_irq(&info->io_lock);
+ spin_unlock_irq(&rinfo->io_lock);
return BLK_MQ_RQ_QUEUE_ERROR;
}
@@ -666,22 +685,27 @@ static int blkfront_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
blk_rq_cur_sectors(req), blk_rq_sectors(req),
rq_data_dir(req) ? "write" : "read");
- if (blkif_queue_request(req)) {
+ if (blkif_queue_request(req, rinfo->hctx_index)) {
wait:
/* Avoid pointless unplugs. */
blk_mq_stop_hw_queue(hctx);
- spin_unlock_irq(&info->io_lock);
+ spin_unlock_irq(&rinfo->io_lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
- flush_requests(info);
- spin_unlock_irq(&info->io_lock);
+ flush_requests(info, rinfo->hctx_index);
+ spin_unlock_irq(&rinfo->io_lock);
return BLK_MQ_RQ_QUEUE_OK;
}
static int blkfront_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int index)
{
+ struct blkfront_info *info = (struct blkfront_info *)data;
+
+ hctx->driver_data = &info->rinfo[index];
+ info->rinfo[index].hctx_index = index;
+
return 0;
}
@@ -704,10 +728,10 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
struct request_queue *rq;
struct blkfront_info *info = gd->private_data;
- if (hardware_queues) {
+ if (info->hardware_queues) {
memset(&info->tag_set, 0, sizeof(info->tag_set));
info->tag_set.ops = &blkfront_mq_ops;
- info->tag_set.nr_hw_queues = hardware_queues;
+ info->tag_set.nr_hw_queues = info->hardware_queues;
info->tag_set.queue_depth = BLK_RING_SIZE;
info->tag_set.numa_node = NUMA_NO_NODE;
info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
@@ -722,7 +746,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
return -1;
}
} else {
- rq = blk_init_queue(do_blkif_request, &info->io_lock);
+ rq = blk_init_queue(do_blkif_request, &info->rinfo[0].io_lock);
if (rq == NULL)
return -1;
}
@@ -945,28 +969,40 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
return err;
}
+void blk_mq_free_queue(struct request_queue *q);
+
static void xlvbd_release_gendisk(struct blkfront_info *info)
{
unsigned int minor, nr_minors;
- unsigned long flags;
+ unsigned long *flags;
+ int i;
if (info->rq == NULL)
return;
- spin_lock_irqsave(&info->io_lock, flags);
+ flags = kzalloc(sizeof(unsigned long) * info->nr_rings,
+ GFP_KERNEL);
+ if (!flags)
+ return;
- /* No more blkif_request(). */
- if (hardware_queues)
+ /* No more blkif_request() and no more gnttab callback work. */
+ if (info->hardware_queues) {
blk_mq_stop_hw_queues(info->rq);
- else
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ spin_lock_irqsave(&info->rinfo[i].io_lock, flags[i]);
+ gnttab_cancel_free_callback(&info->rinfo[i].callback);
+ spin_unlock_irqrestore(&info->rinfo[i].io_lock, flags[i]);
+ }
+ } else {
+ spin_lock_irqsave(&info->rinfo[0].io_lock, flags[0]);
blk_stop_queue(info->rq);
-
- /* No more gnttab callback work. */
- gnttab_cancel_free_callback(&info->callback);
- spin_unlock_irqrestore(&info->io_lock, flags);
+ gnttab_cancel_free_callback(&info->rinfo[0].callback);
+ spin_unlock_irqrestore(&info->rinfo[0].io_lock, flags[0]);
+ }
/* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+ for (i = 0 ; i < info->nr_rings ; i++)
+ flush_work(&info->rinfo[i].work);
del_gendisk(info->gd);
@@ -982,12 +1018,13 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
info->gd = NULL;
}
-static void kick_pending_request_queues(struct blkfront_info *info)
+static void kick_pending_request_queues(struct blkfront_ring_info *rinfo)
{
- if (!RING_FULL(&info->ring)) {
- if (hardware_queues) {
+ if (!RING_FULL(&rinfo->ring)) {
+ struct blkfront_info *info = rinfo->info;
+ if (info->hardware_queues)
blk_mq_start_stopped_hw_queues(info->rq, 0);
- } else {
+ else {
/* Re-enable calldowns. */
blk_start_queue(info->rq);
/* Kick things off immediately. */
@@ -998,83 +1035,42 @@ static void kick_pending_request_queues(struct blkfront_info *info)
static void blkif_restart_queue(struct work_struct *work)
{
- struct blkfront_info *info = container_of(work, struct blkfront_info, work);
+ struct blkfront_ring_info *rinfo = container_of(work,
+ struct blkfront_ring_info, work);
+ struct blkfront_info *info = rinfo->info;
- spin_lock_irq(&info->io_lock);
+ spin_lock_irq(&rinfo->io_lock);
if (info->connected == BLKIF_STATE_CONNECTED)
- kick_pending_request_queues(info);
- spin_unlock_irq(&info->io_lock);
+ kick_pending_request_queues(rinfo);
+ spin_unlock_irq(&rinfo->io_lock);
}
-static void blkif_free(struct blkfront_info *info, int suspend)
+static void blkif_free_ring(struct blkfront_ring_info *rinfo,
+ int persistent)
{
struct grant *persistent_gnt;
- struct grant *n;
int i, j, segs;
- /* 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) {
- if (hardware_queues)
- blk_mq_stop_hw_queues(info->rq);
- else
- blk_stop_queue(info->rq);
- }
-
- /* 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(pfn_to_page(persistent_gnt->pfn));
- kfree(persistent_gnt);
- }
- }
- BUG_ON(info->persistent_gnts_c != 0);
-
- /*
- * Remove indirect pages, this only happens when using indirect
- * descriptors but not persistent grants
- */
- if (!list_empty(&info->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_del(&indirect_page->lru);
- __free_page(indirect_page);
- }
- }
-
for (i = 0; i < BLK_RING_SIZE; 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)
+ if (persistent)
__free_page(pfn_to_page(persistent_gnt->pfn));
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
@@ -1082,44 +1078,105 @@ 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(pfn_to_page(persistent_gnt->pfn));
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);
+ /* Free resources associated with old device channel. */
+ if (rinfo->ring_ref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(rinfo->ring_ref, 0,
+ (unsigned long)rinfo->ring.sring);
+ rinfo->ring_ref = GRANT_INVALID_REF;
+ rinfo->ring.sring = NULL;
+ }
+ if (rinfo->irq)
+ unbind_from_irqhandler(rinfo->irq, rinfo);
+ rinfo->evtchn = rinfo->irq = 0;
- /* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+}
- /* Free resources associated with old device channel. */
- if (info->ring_ref != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(info->ring_ref, 0,
- (unsigned long)info->ring.sring);
- info->ring_ref = GRANT_INVALID_REF;
- info->ring.sring = NULL;
+static void blkif_free(struct blkfront_info *info, int suspend)
+{
+ struct grant *persistent_gnt;
+ struct grant *n;
+ int i;
+
+ info->connected = suspend ?
+ BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED;
+
+ /* Prevent new requests being issued until we fix things up. */
+ /* No more blkif_request() and no more gnttab callback work. */
+ if (!info->hardware_queues && info->rq) {
+ spin_lock_irq(&info->rinfo[0].io_lock);
+ blk_stop_queue(info->rq);
+ gnttab_cancel_free_callback(&info->rinfo[0].callback);
+ spin_unlock_irq(&info->rinfo[0].io_lock);
+ } else {
+ blk_mq_stop_hw_queues(info->rq);
+
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ struct blkfront_ring_info *rinfo = &info->rinfo[i];
+
+ spin_lock_irq(&info->rinfo[i].io_lock);
+ /* 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(pfn_to_page(persistent_gnt->pfn));
+ kfree(persistent_gnt);
+ }
+ }
+ BUG_ON(rinfo->persistent_gnts_c != 0);
+
+ /*
+ * Remove indirect pages, this only happens when using indirect
+ * descriptors but not persistent grants
+ */
+ if (!list_empty(&rinfo->indirect_pages)) {
+ struct page *indirect_page, *n;
+
+ BUG_ON(info->feature_persistent);
+ list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
+ list_del(&indirect_page->lru);
+ __free_page(indirect_page);
+ }
+ }
+
+ blkif_free_ring(&info->rinfo[i], info->feature_persistent);
+ }
+
+ gnttab_cancel_free_callback(&info->rinfo[i].callback);
+ spin_unlock_irq(&info->rinfo[i].io_lock);
}
- if (info->irq)
- unbind_from_irqhandler(info->irq, info);
- info->evtchn = info->irq = 0;
+ /* Flush gnttab callback work. Must be done with no locks held. */
+ for (i = 0 ; i < info->nr_rings ; i++)
+ flush_work(&info->rinfo[i].work);
}
-static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
+static void blkif_completion(struct blk_shadow *s,
+ struct blkfront_ring_info *rinfo,
struct blkif_response *bret)
{
+ struct blkfront_info *info = rinfo->info;
int i = 0;
struct scatterlist *sg;
char *bvec_data;
@@ -1160,8 +1217,8 @@ 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
@@ -1171,7 +1228,7 @@ 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) {
@@ -1180,8 +1237,8 @@ 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;
@@ -1191,9 +1248,9 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
* available pages for indirect grefs.
*/
indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
- 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);
}
}
}
@@ -1205,24 +1262,25 @@ 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->info;
int error;
- spin_lock_irqsave(&info->io_lock, flags);
+ spin_lock_irqsave(&rinfo->io_lock, flags);
if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) {
- spin_unlock_irqrestore(&info->io_lock, flags);
+ spin_unlock_irqrestore(&rinfo->io_lock, flags);
return IRQ_HANDLED;
}
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
@@ -1236,12 +1294,12 @@ 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);
+ blkif_completion(&rinfo->shadow[id], rinfo, bret);
- 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;
@@ -1260,7 +1318,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq);
}
- if (hardware_queues)
+ if (info->hardware_queues)
blk_mq_complete_request(req);
else
__blk_end_request_all(req, error);
@@ -1273,7 +1331,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
error = req->errors = -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 = req->errors = -EOPNOTSUPP;
@@ -1292,7 +1350,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
"request: %x\n", bret->status);
- if (hardware_queues)
+ if (info->hardware_queues)
blk_mq_complete_request(req);
else
__blk_end_request_all(req, error);
@@ -1302,31 +1360,31 @@ 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(rinfo);
- spin_unlock_irqrestore(&info->io_lock, flags);
+ spin_unlock_irqrestore(&rinfo->io_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;
- info->ring_ref = GRANT_INVALID_REF;
+ rinfo->ring_ref = GRANT_INVALID_REF;
sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if (!sring) {
@@ -1334,32 +1392,32 @@ static int setup_blkring(struct xenbus_device *dev,
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+ FRONT_RING_INIT(&rinfo->ring, sring, PAGE_SIZE);
- err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
+ err = xenbus_grant_ring(dev, virt_to_mfn(rinfo->ring.sring));
if (err < 0) {
free_page((unsigned long)sring);
- info->ring.sring = NULL;
+ rinfo->ring.sring = NULL;
goto fail;
}
- info->ring_ref = err;
+ rinfo->ring_ref = err;
- 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:
- blkif_free(info, 0);
+ blkif_free(rinfo->info, 0);
return err;
}
@@ -1369,13 +1427,16 @@ static int talk_to_blkback(struct xenbus_device *dev,
struct blkfront_info *info)
{
const char *message = NULL;
+ char ring_ref_s[64] = "", evtchn_s[64] = "";
struct xenbus_transaction xbt;
- int err;
+ int i, err;
- /* Create shared ring, alloc event channel. */
- err = setup_blkring(dev, info);
- if (err)
- goto out;
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ /* Create shared ring, alloc event channel. */
+ err = setup_blkring(dev, &info->rinfo[i]);
+ if (err)
+ goto out;
+ }
again:
err = xenbus_transaction_start(&xbt);
@@ -1384,18 +1445,30 @@ again:
goto destroy_blkring;
}
- err = xenbus_printf(xbt, dev->nodename,
- "ring-ref", "%u", info->ring_ref);
- if (err) {
- message = "writing ring-ref";
- goto abort_transaction;
- }
- err = xenbus_printf(xbt, dev->nodename,
- "event-channel", "%u", info->evtchn);
- if (err) {
- message = "writing event-channel";
- goto abort_transaction;
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ if (!info->hardware_queues) {
+ BUG_ON(i > 0);
+ /* Support old XenStore keys */
+ snprintf(ring_ref_s, 64, "ring-ref");
+ snprintf(evtchn_s, 64, "event-channel");
+ } else {
+ snprintf(ring_ref_s, 64, "ring-ref-%d", i);
+ snprintf(evtchn_s, 64, "event-channel-%d", i);
+ }
+ err = xenbus_printf(xbt, dev->nodename,
+ ring_ref_s, "%u", info->rinfo[i].ring_ref);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ err = xenbus_printf(xbt, dev->nodename,
+ evtchn_s, "%u", info->rinfo[i].evtchn);
+ if (err) {
+ message = "writing event-channel";
+ goto abort_transaction;
+ }
}
+
err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
XEN_IO_PROTO_ABI_NATIVE);
if (err) {
@@ -1439,8 +1512,9 @@ again:
static int blkfront_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
- int err, vdevice, i;
+ int err, vdevice, i, r;
struct blkfront_info *info;
+ unsigned int nr_queues;
/* FIXME: Use dynamic device id if this is not set. */
err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1491,23 +1565,47 @@ static int blkfront_probe(struct xenbus_device *dev,
}
mutex_init(&info->mutex);
- spin_lock_init(&info->io_lock);
info->xbdev = dev;
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);
-
- for (i = 0; i < BLK_RING_SIZE; i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
/* Front end dir is a number, which is used as the id. */
info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
dev_set_drvdata(&dev->dev, info);
+ /* Gather the number of hardware queues as soon as possible */
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "nr_supported_hw_queues", "%u", &nr_queues,
+ NULL);
+ if (err)
+ info->hardware_queues = 0;
+ else
+ info->hardware_queues = nr_queues;
+ /*
+ * The backend has told us the number of hw queues he wants.
+ * Allocate the correct number of rings.
+ */
+ info->nr_rings = info->hardware_queues ? : 1;
+ pr_info("blkfront: %d hardware queues, %d rings\n",
+ info->hardware_queues, info->nr_rings);
+
+ info->rinfo = kzalloc(info->nr_rings *
+ sizeof(struct blkfront_ring_info),
+ GFP_KERNEL);
+ for (r = 0 ; r < info->nr_rings ; r++) {
+ struct blkfront_ring_info *rinfo = &info->rinfo[r];
+
+ rinfo->info = info;
+ rinfo->persistent_gnts_c = 0;
+ INIT_LIST_HEAD(&rinfo->grants);
+ INIT_LIST_HEAD(&rinfo->indirect_pages);
+ INIT_WORK(&rinfo->work, blkif_restart_queue);
+ spin_lock_init(&rinfo->io_lock);
+ for (i = 0; i < BLK_RING_SIZE; i++)
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
+ }
+
err = talk_to_blkback(dev, info);
if (err) {
kfree(info);
@@ -1533,107 +1631,126 @@ static void split_bio_end(struct bio *bio, int error)
bio_put(bio);
}
-static int blkif_recover(struct blkfront_info *info)
+static int blkif_setup_shadow(struct blkfront_ring_info *rinfo,
+ struct blk_shadow **copy)
{
int i;
+
+ /* 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; i++)
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->shadow_free = rinfo->ring.req_prod_pvt;
+ rinfo->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
+
+ return 0;
+}
+
+static int blkif_recover(struct blkfront_info *info)
+{
+ int i, r;
struct request *req, *n;
struct blk_shadow *copy;
- int rc;
+ int rc = 0;
struct bio *bio, *cloned_bio;
- struct bio_list bio_list, merge_bio;
+ struct bio_list uninitialized_var(bio_list), merge_bio;
unsigned int segs, offset;
int pending, size;
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;
+ segs = blkfront_gather_indirect(info);
- /* Stage 2: Set up free list. */
- memset(&info->shadow, 0, sizeof(info->shadow));
- for (i = 0; i < BLK_RING_SIZE; i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow_free = info->ring.req_prod_pvt;
- info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
+ for (r = 0 ; r < info->nr_rings ; i++) {
+ rc |= blkif_setup_shadow(&info->rinfo[i], ©);
- rc = blkfront_setup_indirect(info);
- if (rc) {
- kfree(copy);
- return rc;
- }
+ rc |= blkfront_setup_indirect(&info->rinfo[i], segs);
+ if (rc) {
+ kfree(copy);
+ return rc;
+ }
- 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; i++) {
- /* Not in use? */
- if (!copy[i].request)
- continue;
+ 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; 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)) {
/*
- * 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(©[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(©[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_put_request(copy[i].request);
}
- 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_put_request(copy[i].request);
- }
- kfree(copy);
+ kfree(copy);
+ }
/*
- * Empty the queue, this is important because we might have
- * requests in the queue with more segments than what we
- * can handle now.
+ * If we are using the request interface, empty the queue,
+ * this is important because we might have requests in the
+ * queue with more segments than what we can handle now.
*/
- spin_lock_irq(&info->io_lock);
- while ((req = blk_fetch_request(info->rq)) != NULL) {
- if (req->cmd_flags &
- (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
- list_add(&req->queuelist, &requests);
- continue;
+ if (!info->hardware_queues) {
+ spin_lock_irq(&info->rinfo[0].io_lock);
+ while ((req = blk_fetch_request(info->rq)) != NULL) {
+ if (req->cmd_flags &
+ (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
+ list_add(&req->queuelist, &requests);
+ continue;
+ }
+ merge_bio.head = req->bio;
+ merge_bio.tail = req->biotail;
+ bio_list_merge(&bio_list, &merge_bio);
+ req->bio = NULL;
+ if (req->cmd_flags & (REQ_FLUSH | REQ_FUA))
+ pr_alert("diskcache flush request found!\n");
+ __blk_put_request(info->rq, req);
}
- merge_bio.head = req->bio;
- merge_bio.tail = req->biotail;
- bio_list_merge(&bio_list, &merge_bio);
- req->bio = NULL;
- if (req->cmd_flags & (REQ_FLUSH | REQ_FUA))
- pr_alert("diskcache flush request found!\n");
- __blk_put_request(info->rq, req);
+ spin_unlock_irq(&info->rinfo[0].io_lock);
}
- spin_unlock_irq(&info->io_lock);
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 (i = 0 ; i < info->nr_rings ; i++) {
+ spin_lock_irq(&info->rinfo[i].io_lock);
+
+ /* Kick any other new requests queued since we resumed */
+ kick_pending_request_queues(&info->rinfo[i]);
+
+ list_for_each_entry_safe(req, n, &requests, queuelist) {
+ /* Requeue pending requests (flush or discard) */
+ list_del_init(&req->queuelist);
+ BUG_ON(req->nr_phys_segments > segs);
+ blk_requeue_request(info->rq, req);
+ }
- list_for_each_entry_safe(req, n, &requests, queuelist) {
- /* Requeue pending requests (flush or discard) */
- list_del_init(&req->queuelist);
- BUG_ON(req->nr_phys_segments > segs);
- blk_requeue_request(info->rq, req);
+ spin_unlock_irq(&info->rinfo[i].io_lock);
}
- spin_unlock_irq(&info->io_lock);
while ((bio = bio_list_pop(&bio_list)) != NULL) {
/* Traverse the list of pending bios and re-queue them */
@@ -1758,14 +1875,15 @@ 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_gather_indirect(struct blkfront_info *info)
{
unsigned int indirect_segments, segs;
- int err, i;
+ int err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-max-indirect-segments", "%u",
+ &indirect_segments,
+ NULL);
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-max-indirect-segments", "%u", &indirect_segments,
- NULL);
if (err) {
info->max_indirect_segments = 0;
segs = BLKIF_MAX_SEGMENTS_PER_REQUEST;
@@ -1775,7 +1893,16 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
segs = info->max_indirect_segments;
}
- err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
+ return segs;
+}
+
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo,
+ unsigned int segs)
+{
+ struct blkfront_info *info = rinfo->info;
+ int err, i;
+
+ err = fill_grant_buffer(rinfo, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
if (err)
goto out_of_memory;
@@ -1787,31 +1914,31 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
*/
int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE;
- 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; i++) {
- info->shadow[i].grants_used = kzalloc(
- sizeof(info->shadow[i].grants_used[0]) * segs,
+ rinfo->shadow[i].grants_used = kzalloc(
+ sizeof(rinfo->shadow[i].grants_used[0]) * segs,
GFP_NOIO);
- info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO);
+ rinfo->shadow[i].sg = kzalloc(sizeof(rinfo->shadow[i].sg[0]) * segs, 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(segs),
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, segs);
+ sg_init_table(rinfo->shadow[i].sg, segs);
}
@@ -1819,16 +1946,16 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
out_of_memory:
for (i = 0; i < BLK_RING_SIZE; 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);
}
@@ -1846,7 +1973,8 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned long sector_size;
unsigned int physical_sector_size;
unsigned int binfo;
- int err;
+ unsigned int segs;
+ int i, err;
int barrier, flush, discard, persistent;
switch (info->connected) {
@@ -1950,11 +2078,14 @@ static void blkfront_connect(struct blkfront_info *info)
else
info->feature_persistent = persistent;
- err = blkfront_setup_indirect(info);
- if (err) {
- xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
- info->xbdev->otherend);
- return;
+ segs = blkfront_gather_indirect(info);
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ err = blkfront_setup_indirect(&info->rinfo[i], segs);
+ if (err) {
+ xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
+ info->xbdev->otherend);
+ return;
+ }
}
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size,
@@ -1967,11 +2098,13 @@ 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);
+ /* Kick pending requests. */
+ for (i = 0 ; i < info->nr_rings ; i++) {
+ spin_lock_irq(&info->rinfo[i].io_lock);
+ kick_pending_request_queues(&info->rinfo[i]);
+ spin_unlock_irq(&info->rinfo[i].io_lock);
+ }
add_disk(info->gd);
--
2.0.4
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH RFC 4/4] xen, blkback: add support for multiple block rings
2014-08-22 11:20 [PATCH RFC 0/4] Multi-queue support for xen-blkfront and xen-blkback Arianna Avanzini
` (2 preceding siblings ...)
2014-08-22 11:20 ` [PATCH RFC 3/4] xen, blkfront: introduce support for multiple hw queues Arianna Avanzini
@ 2014-08-22 11:20 ` Arianna Avanzini
2014-08-22 13:15 ` David Vrabel
2014-09-15 9:23 ` [Xen-devel] [PATCH RFC 0/4] Multi-queue support for xen-blkfront and xen-blkback Roger Pau Monné
4 siblings, 1 reply; 18+ messages in thread
From: Arianna Avanzini @ 2014-08-22 11:20 UTC (permalink / raw)
To: konrad.wilk, boris.ostrovsky, david.vrabel, xen-devel, linux-kernel
Cc: bob.liu, felipe.franciosi, axboe, avanzini.arianna
This commit adds to xen-blkback the support to retrieve the block
layer API being used and the number of available hardware queues,
in case the block layer is using the multi-queue API. This commit
also lets the driver advertise the number of available hardware
queues to the frontend via XenStore, therefore allowing for actual
multiple I/O rings to be used.
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
---
drivers/block/xen-blkback/blkback.c | 376 +++++++++++++++-------------
drivers/block/xen-blkback/common.h | 111 +++++----
drivers/block/xen-blkback/xenbus.c | 475 ++++++++++++++++++++++++------------
3 files changed, 590 insertions(+), 372 deletions(-)
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 64c60ed..08edcae 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -75,6 +75,8 @@ MODULE_PARM_DESC(max_buffer_pages,
* algorithm.
*/
+#define XEN_RING_MAX_PGRANTS(nr_rings) ((xen_blkif_max_pgrants / nr_rings > 16) ? \
+ xen_blkif_max_pgrants / nr_rings : 16)
static int xen_blkif_max_pgrants = 1056;
module_param_named(max_persistent_grants, xen_blkif_max_pgrants, int, 0644);
MODULE_PARM_DESC(max_persistent_grants,
@@ -103,71 +105,71 @@ module_param(log_stats, int, 0644);
/* Number of free pages to remove on each call to free_xenballooned_pages */
#define NUM_BATCH_FREE_PAGES 10
-static inline int get_free_page(struct xen_blkif *blkif, struct page **page)
+static inline int get_free_page(struct xen_blkif_ring *ring, struct page **page)
{
unsigned long flags;
- spin_lock_irqsave(&blkif->free_pages_lock, flags);
- if (list_empty(&blkif->free_pages)) {
- BUG_ON(blkif->free_pages_num != 0);
- spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
+ spin_lock_irqsave(&ring->free_pages_lock, flags);
+ if (list_empty(&ring->free_pages)) {
+ BUG_ON(ring->free_pages_num != 0);
+ spin_unlock_irqrestore(&ring->free_pages_lock, flags);
return alloc_xenballooned_pages(1, page, false);
}
- BUG_ON(blkif->free_pages_num == 0);
- page[0] = list_first_entry(&blkif->free_pages, struct page, lru);
+ BUG_ON(ring->free_pages_num == 0);
+ page[0] = list_first_entry(&ring->free_pages, struct page, lru);
list_del(&page[0]->lru);
- blkif->free_pages_num--;
- spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
+ ring->free_pages_num--;
+ spin_unlock_irqrestore(&ring->free_pages_lock, flags);
return 0;
}
-static inline void put_free_pages(struct xen_blkif *blkif, struct page **page,
- int num)
+static inline void put_free_pages(struct xen_blkif_ring *ring,
+ struct page **page, int num)
{
unsigned long flags;
int i;
- spin_lock_irqsave(&blkif->free_pages_lock, flags);
+ spin_lock_irqsave(&ring->free_pages_lock, flags);
for (i = 0; i < num; i++)
- list_add(&page[i]->lru, &blkif->free_pages);
- blkif->free_pages_num += num;
- spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
+ list_add(&page[i]->lru, &ring->free_pages);
+ ring->free_pages_num += num;
+ spin_unlock_irqrestore(&ring->free_pages_lock, flags);
}
-static inline void shrink_free_pagepool(struct xen_blkif *blkif, int num)
+static inline void shrink_free_pagepool(struct xen_blkif_ring *ring, int num)
{
/* Remove requested pages in batches of NUM_BATCH_FREE_PAGES */
struct page *page[NUM_BATCH_FREE_PAGES];
unsigned int num_pages = 0;
unsigned long flags;
- spin_lock_irqsave(&blkif->free_pages_lock, flags);
- while (blkif->free_pages_num > num) {
- BUG_ON(list_empty(&blkif->free_pages));
- page[num_pages] = list_first_entry(&blkif->free_pages,
+ spin_lock_irqsave(&ring->free_pages_lock, flags);
+ while (ring->free_pages_num > num) {
+ BUG_ON(list_empty(&ring->free_pages));
+ page[num_pages] = list_first_entry(&ring->free_pages,
struct page, lru);
list_del(&page[num_pages]->lru);
- blkif->free_pages_num--;
+ ring->free_pages_num--;
if (++num_pages == NUM_BATCH_FREE_PAGES) {
- spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
+ spin_unlock_irqrestore(&ring->free_pages_lock, flags);
free_xenballooned_pages(num_pages, page);
- spin_lock_irqsave(&blkif->free_pages_lock, flags);
+ spin_lock_irqsave(&ring->free_pages_lock, flags);
num_pages = 0;
}
}
- spin_unlock_irqrestore(&blkif->free_pages_lock, flags);
+ spin_unlock_irqrestore(&ring->free_pages_lock, flags);
if (num_pages != 0)
free_xenballooned_pages(num_pages, page);
}
#define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page)))
-static int do_block_io_op(struct xen_blkif *blkif);
-static int dispatch_rw_block_io(struct xen_blkif *blkif,
+static int do_block_io_op(struct xen_blkif_ring *ring);
+static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
struct blkif_request *req,
struct pending_req *pending_req);
-static void make_response(struct xen_blkif *blkif, u64 id,
+static void make_response(struct xen_blkif_ring *ring, u64 id,
unsigned short op, int st);
#define foreach_grant_safe(pos, n, rbtree, node) \
@@ -188,19 +190,21 @@ static void make_response(struct xen_blkif *blkif, u64 id,
* bit operations to modify the flags of a persistent grant and to count
* the number of used grants.
*/
-static int add_persistent_gnt(struct xen_blkif *blkif,
+static int add_persistent_gnt(struct xen_blkif_ring *ring,
struct persistent_gnt *persistent_gnt)
{
+ struct xen_blkif *blkif = ring->blkif;
struct rb_node **new = NULL, *parent = NULL;
struct persistent_gnt *this;
- if (blkif->persistent_gnt_c >= xen_blkif_max_pgrants) {
+ if (ring->persistent_gnt_c >=
+ XEN_RING_MAX_PGRANTS(ring->blkif->allocated_rings)) {
if (!blkif->vbd.overflow_max_grants)
blkif->vbd.overflow_max_grants = 1;
return -EBUSY;
}
/* Figure out where to put new node */
- new = &blkif->persistent_gnts.rb_node;
+ new = &ring->persistent_gnts.rb_node;
while (*new) {
this = container_of(*new, struct persistent_gnt, node);
@@ -219,19 +223,19 @@ static int add_persistent_gnt(struct xen_blkif *blkif,
set_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags);
/* Add new node and rebalance tree. */
rb_link_node(&(persistent_gnt->node), parent, new);
- rb_insert_color(&(persistent_gnt->node), &blkif->persistent_gnts);
- blkif->persistent_gnt_c++;
- atomic_inc(&blkif->persistent_gnt_in_use);
+ rb_insert_color(&(persistent_gnt->node), &ring->persistent_gnts);
+ ring->persistent_gnt_c++;
+ atomic_inc(&ring->persistent_gnt_in_use);
return 0;
}
-static struct persistent_gnt *get_persistent_gnt(struct xen_blkif *blkif,
+static struct persistent_gnt *get_persistent_gnt(struct xen_blkif_ring *ring,
grant_ref_t gref)
{
struct persistent_gnt *data;
struct rb_node *node = NULL;
- node = blkif->persistent_gnts.rb_node;
+ node = ring->persistent_gnts.rb_node;
while (node) {
data = container_of(node, struct persistent_gnt, node);
@@ -245,25 +249,25 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif *blkif,
return NULL;
}
set_bit(PERSISTENT_GNT_ACTIVE, data->flags);
- atomic_inc(&blkif->persistent_gnt_in_use);
+ atomic_inc(&ring->persistent_gnt_in_use);
return data;
}
}
return NULL;
}
-static void put_persistent_gnt(struct xen_blkif *blkif,
+static void put_persistent_gnt(struct xen_blkif_ring *ring,
struct persistent_gnt *persistent_gnt)
{
if(!test_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags))
pr_alert_ratelimited(DRV_PFX " freeing a grant already unused");
set_bit(PERSISTENT_GNT_WAS_ACTIVE, persistent_gnt->flags);
clear_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags);
- atomic_dec(&blkif->persistent_gnt_in_use);
+ atomic_dec(&ring->persistent_gnt_in_use);
}
-static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
- unsigned int num)
+static void free_persistent_gnts(struct xen_blkif_ring *ring,
+ struct rb_root *root, unsigned int num)
{
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
@@ -288,7 +292,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
ret = gnttab_unmap_refs(unmap, NULL, pages,
segs_to_unmap);
BUG_ON(ret);
- put_free_pages(blkif, pages, segs_to_unmap);
+ put_free_pages(ring, pages, segs_to_unmap);
segs_to_unmap = 0;
}
@@ -305,10 +309,10 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct persistent_gnt *persistent_gnt;
int ret, segs_to_unmap = 0;
- struct xen_blkif *blkif = container_of(work, typeof(*blkif), persistent_purge_work);
+ struct xen_blkif_ring *ring = container_of(work, typeof(*ring), persistent_purge_work);
- while(!list_empty(&blkif->persistent_purge_list)) {
- persistent_gnt = list_first_entry(&blkif->persistent_purge_list,
+ while(!list_empty(&ring->persistent_purge_list)) {
+ persistent_gnt = list_first_entry(&ring->persistent_purge_list,
struct persistent_gnt,
remove_node);
list_del(&persistent_gnt->remove_node);
@@ -324,7 +328,7 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
ret = gnttab_unmap_refs(unmap, NULL, pages,
segs_to_unmap);
BUG_ON(ret);
- put_free_pages(blkif, pages, segs_to_unmap);
+ put_free_pages(ring, pages, segs_to_unmap);
segs_to_unmap = 0;
}
kfree(persistent_gnt);
@@ -332,34 +336,36 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work)
if (segs_to_unmap > 0) {
ret = gnttab_unmap_refs(unmap, NULL, pages, segs_to_unmap);
BUG_ON(ret);
- put_free_pages(blkif, pages, segs_to_unmap);
+ put_free_pages(ring, pages, segs_to_unmap);
}
}
-static void purge_persistent_gnt(struct xen_blkif *blkif)
+static void purge_persistent_gnt(struct xen_blkif_ring *ring)
{
+ struct xen_blkif *blkif = ring->blkif;
struct persistent_gnt *persistent_gnt;
struct rb_node *n;
unsigned int num_clean, total;
bool scan_used = false, clean_used = false;
struct rb_root *root;
+ unsigned nr_rings = ring->blkif->allocated_rings;
- if (blkif->persistent_gnt_c < xen_blkif_max_pgrants ||
- (blkif->persistent_gnt_c == xen_blkif_max_pgrants &&
+ if (ring->persistent_gnt_c < XEN_RING_MAX_PGRANTS(nr_rings) ||
+ (ring->persistent_gnt_c == XEN_RING_MAX_PGRANTS(nr_rings) &&
!blkif->vbd.overflow_max_grants)) {
return;
}
- if (work_pending(&blkif->persistent_purge_work)) {
+ if (work_pending(&ring->persistent_purge_work)) {
pr_alert_ratelimited(DRV_PFX "Scheduled work from previous purge is still pending, cannot purge list\n");
return;
}
- num_clean = (xen_blkif_max_pgrants / 100) * LRU_PERCENT_CLEAN;
- num_clean = blkif->persistent_gnt_c - xen_blkif_max_pgrants + num_clean;
- num_clean = min(blkif->persistent_gnt_c, num_clean);
+ num_clean = (XEN_RING_MAX_PGRANTS(nr_rings) / 100) * LRU_PERCENT_CLEAN;
+ num_clean = ring->persistent_gnt_c - XEN_RING_MAX_PGRANTS(nr_rings) + num_clean;
+ num_clean = min(ring->persistent_gnt_c, num_clean);
if ((num_clean == 0) ||
- (num_clean > (blkif->persistent_gnt_c - atomic_read(&blkif->persistent_gnt_in_use))))
+ (num_clean > (ring->persistent_gnt_c - atomic_read(&ring->persistent_gnt_in_use))))
return;
/*
@@ -375,8 +381,8 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
pr_debug(DRV_PFX "Going to purge %u persistent grants\n", num_clean);
- BUG_ON(!list_empty(&blkif->persistent_purge_list));
- root = &blkif->persistent_gnts;
+ BUG_ON(!list_empty(&ring->persistent_purge_list));
+ root = &ring->persistent_gnts;
purge_list:
foreach_grant_safe(persistent_gnt, n, root, node) {
BUG_ON(persistent_gnt->handle ==
@@ -395,7 +401,7 @@ purge_list:
rb_erase(&persistent_gnt->node, root);
list_add(&persistent_gnt->remove_node,
- &blkif->persistent_purge_list);
+ &ring->persistent_purge_list);
if (--num_clean == 0)
goto finished;
}
@@ -416,11 +422,11 @@ finished:
goto purge_list;
}
- blkif->persistent_gnt_c -= (total - num_clean);
+ ring->persistent_gnt_c -= (total - num_clean);
blkif->vbd.overflow_max_grants = 0;
/* We can defer this work */
- schedule_work(&blkif->persistent_purge_work);
+ schedule_work(&ring->persistent_purge_work);
pr_debug(DRV_PFX "Purged %u/%u\n", (total - num_clean), total);
return;
}
@@ -428,18 +434,18 @@ finished:
/*
* Retrieve from the 'pending_reqs' a free pending_req structure to be used.
*/
-static struct pending_req *alloc_req(struct xen_blkif *blkif)
+static struct pending_req *alloc_req(struct xen_blkif_ring *ring)
{
struct pending_req *req = NULL;
unsigned long flags;
- spin_lock_irqsave(&blkif->pending_free_lock, flags);
- if (!list_empty(&blkif->pending_free)) {
- req = list_entry(blkif->pending_free.next, struct pending_req,
+ spin_lock_irqsave(&ring->pending_free_lock, flags);
+ if (!list_empty(&ring->pending_free)) {
+ req = list_entry(ring->pending_free.next, struct pending_req,
free_list);
list_del(&req->free_list);
}
- spin_unlock_irqrestore(&blkif->pending_free_lock, flags);
+ spin_unlock_irqrestore(&ring->pending_free_lock, flags);
return req;
}
@@ -447,17 +453,17 @@ static struct pending_req *alloc_req(struct xen_blkif *blkif)
* Return the 'pending_req' structure back to the freepool. We also
* wake up the thread if it was waiting for a free page.
*/
-static void free_req(struct xen_blkif *blkif, struct pending_req *req)
+static void free_req(struct xen_blkif_ring *ring, struct pending_req *req)
{
unsigned long flags;
int was_empty;
- spin_lock_irqsave(&blkif->pending_free_lock, flags);
- was_empty = list_empty(&blkif->pending_free);
- list_add(&req->free_list, &blkif->pending_free);
- spin_unlock_irqrestore(&blkif->pending_free_lock, flags);
+ spin_lock_irqsave(&ring->pending_free_lock, flags);
+ was_empty = list_empty(&ring->pending_free);
+ list_add(&req->free_list, &ring->pending_free);
+ spin_unlock_irqrestore(&ring->pending_free_lock, flags);
if (was_empty)
- wake_up(&blkif->pending_free_wq);
+ wake_up(&ring->pending_free_wq);
}
/*
@@ -537,10 +543,10 @@ abort:
/*
* Notification from the guest OS.
*/
-static void blkif_notify_work(struct xen_blkif *blkif)
+static void blkif_notify_work(struct xen_blkif_ring *ring)
{
- blkif->waiting_reqs = 1;
- wake_up(&blkif->wq);
+ ring->waiting_reqs = 1;
+ wake_up(&ring->wq);
}
irqreturn_t xen_blkif_be_int(int irq, void *dev_id)
@@ -553,30 +559,33 @@ irqreturn_t xen_blkif_be_int(int irq, void *dev_id)
* SCHEDULER FUNCTIONS
*/
-static void print_stats(struct xen_blkif *blkif)
+static void print_stats(struct xen_blkif_ring *ring)
{
+ spin_lock_irq(&ring->stats_lock);
pr_info("xen-blkback (%s): oo %3llu | rd %4llu | wr %4llu | f %4llu"
" | ds %4llu | pg: %4u/%4d\n",
- current->comm, blkif->st_oo_req,
- blkif->st_rd_req, blkif->st_wr_req,
- blkif->st_f_req, blkif->st_ds_req,
- blkif->persistent_gnt_c,
- xen_blkif_max_pgrants);
- blkif->st_print = jiffies + msecs_to_jiffies(10 * 1000);
- blkif->st_rd_req = 0;
- blkif->st_wr_req = 0;
- blkif->st_oo_req = 0;
- blkif->st_ds_req = 0;
+ current->comm, ring->st_oo_req,
+ ring->st_rd_req, ring->st_wr_req,
+ ring->st_f_req, ring->st_ds_req,
+ ring->persistent_gnt_c,
+ XEN_RING_MAX_PGRANTS(ring->blkif->allocated_rings));
+ ring->st_print = jiffies + msecs_to_jiffies(10 * 1000);
+ ring->st_rd_req = 0;
+ ring->st_wr_req = 0;
+ ring->st_oo_req = 0;
+ ring->st_ds_req = 0;
+ spin_unlock_irq(&ring->stats_lock);
}
int xen_blkif_schedule(void *arg)
{
- struct xen_blkif *blkif = arg;
+ struct xen_blkif_ring *ring = arg;
+ struct xen_blkif *blkif = ring->blkif;
struct xen_vbd *vbd = &blkif->vbd;
unsigned long timeout;
int ret;
- xen_blkif_get(blkif);
+ xen_ring_get(ring);
while (!kthread_should_stop()) {
if (try_to_freeze())
@@ -587,51 +596,51 @@ int xen_blkif_schedule(void *arg)
timeout = msecs_to_jiffies(LRU_INTERVAL);
timeout = wait_event_interruptible_timeout(
- blkif->wq,
- blkif->waiting_reqs || kthread_should_stop(),
+ ring->wq,
+ ring->waiting_reqs || kthread_should_stop(),
timeout);
if (timeout == 0)
goto purge_gnt_list;
timeout = wait_event_interruptible_timeout(
- blkif->pending_free_wq,
- !list_empty(&blkif->pending_free) ||
+ ring->pending_free_wq,
+ !list_empty(&ring->pending_free) ||
kthread_should_stop(),
timeout);
if (timeout == 0)
goto purge_gnt_list;
- blkif->waiting_reqs = 0;
+ ring->waiting_reqs = 0;
smp_mb(); /* clear flag *before* checking for work */
- ret = do_block_io_op(blkif);
+ ret = do_block_io_op(ring);
if (ret > 0)
- blkif->waiting_reqs = 1;
+ ring->waiting_reqs = 1;
if (ret == -EACCES)
- wait_event_interruptible(blkif->shutdown_wq,
+ wait_event_interruptible(ring->shutdown_wq,
kthread_should_stop());
purge_gnt_list:
if (blkif->vbd.feature_gnt_persistent &&
- time_after(jiffies, blkif->next_lru)) {
- purge_persistent_gnt(blkif);
- blkif->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL);
+ time_after(jiffies, ring->next_lru)) {
+ purge_persistent_gnt(ring);
+ ring->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL);
}
/* Shrink if we have more than xen_blkif_max_buffer_pages */
- shrink_free_pagepool(blkif, xen_blkif_max_buffer_pages);
+ shrink_free_pagepool(ring, xen_blkif_max_buffer_pages);
- if (log_stats && time_after(jiffies, blkif->st_print))
- print_stats(blkif);
+ if (log_stats && time_after(jiffies, ring->st_print))
+ print_stats(ring);
}
/* Drain pending purge work */
- flush_work(&blkif->persistent_purge_work);
+ flush_work(&ring->persistent_purge_work);
if (log_stats)
- print_stats(blkif);
+ print_stats(ring);
- blkif->xenblkd = NULL;
- xen_blkif_put(blkif);
+ ring->xenblkd = NULL;
+ xen_ring_put(ring);
return 0;
}
@@ -639,25 +648,25 @@ purge_gnt_list:
/*
* Remove persistent grants and empty the pool of free pages
*/
-void xen_blkbk_free_caches(struct xen_blkif *blkif)
+void xen_blkbk_free_caches(struct xen_blkif_ring *ring)
{
/* Free all persistent grant pages */
- if (!RB_EMPTY_ROOT(&blkif->persistent_gnts))
- free_persistent_gnts(blkif, &blkif->persistent_gnts,
- blkif->persistent_gnt_c);
+ if (!RB_EMPTY_ROOT(&ring->persistent_gnts))
+ free_persistent_gnts(ring, &ring->persistent_gnts,
+ ring->persistent_gnt_c);
- BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));
- blkif->persistent_gnt_c = 0;
+ BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts));
+ ring->persistent_gnt_c = 0;
/* Since we are shutting down remove all pages from the buffer */
- shrink_free_pagepool(blkif, 0 /* All */);
+ shrink_free_pagepool(ring, 0 /* All */);
}
/*
* Unmap the grant references, and also remove the M2P over-rides
* used in the 'pending_req'.
*/
-static void xen_blkbk_unmap(struct xen_blkif *blkif,
+static void xen_blkbk_unmap(struct xen_blkif_ring *ring,
struct grant_page *pages[],
int num)
{
@@ -668,7 +677,7 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif,
for (i = 0; i < num; i++) {
if (pages[i]->persistent_gnt != NULL) {
- put_persistent_gnt(blkif, pages[i]->persistent_gnt);
+ put_persistent_gnt(ring, pages[i]->persistent_gnt);
continue;
}
if (pages[i]->handle == BLKBACK_INVALID_HANDLE)
@@ -681,21 +690,22 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif,
ret = gnttab_unmap_refs(unmap, NULL, unmap_pages,
invcount);
BUG_ON(ret);
- put_free_pages(blkif, unmap_pages, invcount);
+ put_free_pages(ring, unmap_pages, invcount);
invcount = 0;
}
}
if (invcount) {
ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount);
BUG_ON(ret);
- put_free_pages(blkif, unmap_pages, invcount);
+ put_free_pages(ring, unmap_pages, invcount);
}
}
-static int xen_blkbk_map(struct xen_blkif *blkif,
+static int xen_blkbk_map(struct xen_blkif_ring *ring,
struct grant_page *pages[],
int num, bool ro)
{
+ struct xen_blkif *blkif = ring->blkif;
struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *pages_to_gnt[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct persistent_gnt *persistent_gnt = NULL;
@@ -719,7 +729,7 @@ again:
if (use_persistent_gnts)
persistent_gnt = get_persistent_gnt(
- blkif,
+ ring,
pages[i]->gref);
if (persistent_gnt) {
@@ -730,7 +740,7 @@ again:
pages[i]->page = persistent_gnt->page;
pages[i]->persistent_gnt = persistent_gnt;
} else {
- if (get_free_page(blkif, &pages[i]->page))
+ if (get_free_page(ring, &pages[i]->page))
goto out_of_memory;
addr = vaddr(pages[i]->page);
pages_to_gnt[segs_to_map] = pages[i]->page;
@@ -772,7 +782,8 @@ again:
continue;
}
if (use_persistent_gnts &&
- blkif->persistent_gnt_c < xen_blkif_max_pgrants) {
+ ring->persistent_gnt_c <
+ XEN_RING_MAX_PGRANTS(ring->blkif->allocated_rings)) {
/*
* We are using persistent grants, the grant is
* not mapped but we might have room for it.
@@ -790,7 +801,7 @@ again:
persistent_gnt->gnt = map[new_map_idx].ref;
persistent_gnt->handle = map[new_map_idx].handle;
persistent_gnt->page = pages[seg_idx]->page;
- if (add_persistent_gnt(blkif,
+ if (add_persistent_gnt(ring,
persistent_gnt)) {
kfree(persistent_gnt);
persistent_gnt = NULL;
@@ -798,8 +809,8 @@ again:
}
pages[seg_idx]->persistent_gnt = persistent_gnt;
pr_debug(DRV_PFX " grant %u added to the tree of persistent grants, using %u/%u\n",
- persistent_gnt->gnt, blkif->persistent_gnt_c,
- xen_blkif_max_pgrants);
+ persistent_gnt->gnt, ring->persistent_gnt_c,
+ XEN_RING_MAX_PGRANTS(ring->blkif->allocated_rings));
goto next;
}
if (use_persistent_gnts && !blkif->vbd.overflow_max_grants) {
@@ -823,7 +834,7 @@ next:
out_of_memory:
pr_alert(DRV_PFX "%s: out of memory\n", __func__);
- put_free_pages(blkif, pages_to_gnt, segs_to_map);
+ put_free_pages(ring, pages_to_gnt, segs_to_map);
return -ENOMEM;
}
@@ -831,7 +842,7 @@ static int xen_blkbk_map_seg(struct pending_req *pending_req)
{
int rc;
- rc = xen_blkbk_map(pending_req->blkif, pending_req->segments,
+ rc = xen_blkbk_map(pending_req->ring, pending_req->segments,
pending_req->nr_pages,
(pending_req->operation != BLKIF_OP_READ));
@@ -844,7 +855,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
struct phys_req *preq)
{
struct grant_page **pages = pending_req->indirect_pages;
- struct xen_blkif *blkif = pending_req->blkif;
+ struct xen_blkif_ring *ring = pending_req->ring;
int indirect_grefs, rc, n, nseg, i;
struct blkif_request_segment *segments = NULL;
@@ -855,7 +866,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
for (i = 0; i < indirect_grefs; i++)
pages[i]->gref = req->u.indirect.indirect_grefs[i];
- rc = xen_blkbk_map(blkif, pages, indirect_grefs, true);
+ rc = xen_blkbk_map(ring, pages, indirect_grefs, true);
if (rc)
goto unmap;
@@ -882,20 +893,21 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
unmap:
if (segments)
kunmap_atomic(segments);
- xen_blkbk_unmap(blkif, pages, indirect_grefs);
+ xen_blkbk_unmap(ring, pages, indirect_grefs);
return rc;
}
-static int dispatch_discard_io(struct xen_blkif *blkif,
+static int dispatch_discard_io(struct xen_blkif_ring *ring,
struct blkif_request *req)
{
int err = 0;
int status = BLKIF_RSP_OKAY;
+ struct xen_blkif *blkif = ring->blkif;
struct block_device *bdev = blkif->vbd.bdev;
unsigned long secure;
struct phys_req preq;
- xen_blkif_get(blkif);
+ xen_ring_get(ring);
preq.sector_number = req->u.discard.sector_number;
preq.nr_sects = req->u.discard.nr_sectors;
@@ -907,7 +919,9 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
preq.sector_number + preq.nr_sects, blkif->vbd.pdevice);
goto fail_response;
}
- blkif->st_ds_req++;
+ spin_lock_irq(&ring->stats_lock);
+ ring->st_ds_req++;
+ spin_unlock_irq(&ring->stats_lock);
secure = (blkif->vbd.discard_secure &&
(req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
@@ -923,26 +937,27 @@ fail_response:
} else if (err)
status = BLKIF_RSP_ERROR;
- make_response(blkif, req->u.discard.id, req->operation, status);
- xen_blkif_put(blkif);
+ make_response(ring, req->u.discard.id, req->operation, status);
+ xen_ring_put(ring);
return err;
}
-static int dispatch_other_io(struct xen_blkif *blkif,
+static int dispatch_other_io(struct xen_blkif_ring *ring,
struct blkif_request *req,
struct pending_req *pending_req)
{
- free_req(blkif, pending_req);
- make_response(blkif, req->u.other.id, req->operation,
+ free_req(ring, pending_req);
+ make_response(ring, req->u.other.id, req->operation,
BLKIF_RSP_EOPNOTSUPP);
return -EIO;
}
-static void xen_blk_drain_io(struct xen_blkif *blkif)
+static void xen_blk_drain_io(struct xen_blkif_ring *ring)
{
+ struct xen_blkif *blkif = ring->blkif;
atomic_set(&blkif->drain, 1);
do {
- if (atomic_read(&blkif->inflight) == 0)
+ if (atomic_read(&ring->inflight) == 0)
break;
wait_for_completion_interruptible_timeout(
&blkif->drain_complete, HZ);
@@ -963,12 +978,12 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
if ((pending_req->operation == BLKIF_OP_FLUSH_DISKCACHE) &&
(error == -EOPNOTSUPP)) {
pr_debug(DRV_PFX "flush diskcache op failed, not supported\n");
- xen_blkbk_flush_diskcache(XBT_NIL, pending_req->blkif->be, 0);
+ xen_blkbk_flush_diskcache(XBT_NIL, pending_req->ring->blkif->be, 0);
pending_req->status = BLKIF_RSP_EOPNOTSUPP;
} else if ((pending_req->operation == BLKIF_OP_WRITE_BARRIER) &&
(error == -EOPNOTSUPP)) {
pr_debug(DRV_PFX "write barrier op failed, not supported\n");
- xen_blkbk_barrier(XBT_NIL, pending_req->blkif->be, 0);
+ xen_blkbk_barrier(XBT_NIL, pending_req->ring->blkif->be, 0);
pending_req->status = BLKIF_RSP_EOPNOTSUPP;
} else if (error) {
pr_debug(DRV_PFX "Buffer not up-to-date at end of operation,"
@@ -982,14 +997,15 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
* the proper response on the ring.
*/
if (atomic_dec_and_test(&pending_req->pendcnt)) {
- struct xen_blkif *blkif = pending_req->blkif;
+ struct xen_blkif_ring *ring = pending_req->ring;
+ struct xen_blkif *blkif = ring->blkif;
- xen_blkbk_unmap(blkif,
+ xen_blkbk_unmap(ring,
pending_req->segments,
pending_req->nr_pages);
- make_response(blkif, pending_req->id,
+ make_response(ring, pending_req->id,
pending_req->operation, pending_req->status);
- free_req(blkif, pending_req);
+ free_req(ring, pending_req);
/*
* Make sure the request is freed before releasing blkif,
* or there could be a race between free_req and the
@@ -1002,10 +1018,10 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
* pending_free_wq if there's a drain going on, but it has
* to be taken into account if the current model is changed.
*/
- if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) {
+ if (atomic_dec_and_test(&ring->inflight) && atomic_read(&blkif->drain)) {
complete(&blkif->drain_complete);
}
- xen_blkif_put(blkif);
+ xen_ring_put(ring);
}
}
@@ -1026,9 +1042,10 @@ static void end_block_io_op(struct bio *bio, int error)
* and transmute it to the block API to hand it over to the proper block disk.
*/
static int
-__do_block_io_op(struct xen_blkif *blkif)
+__do_block_io_op(struct xen_blkif_ring *ring)
{
- union blkif_back_rings *blk_rings = &blkif->blk_rings;
+ union blkif_back_rings *blk_rings = &ring->blk_rings;
+ struct xen_blkif *blkif = ring->blkif;
struct blkif_request req;
struct pending_req *pending_req;
RING_IDX rc, rp;
@@ -1054,9 +1071,11 @@ __do_block_io_op(struct xen_blkif *blkif)
break;
}
- pending_req = alloc_req(blkif);
+ pending_req = alloc_req(ring);
if (NULL == pending_req) {
- blkif->st_oo_req++;
+ spin_lock_irq(&ring->stats_lock);
+ ring->st_oo_req++;
+ spin_unlock_irq(&ring->stats_lock);
more_to_do = 1;
break;
}
@@ -1085,16 +1104,16 @@ __do_block_io_op(struct xen_blkif *blkif)
case BLKIF_OP_WRITE_BARRIER:
case BLKIF_OP_FLUSH_DISKCACHE:
case BLKIF_OP_INDIRECT:
- if (dispatch_rw_block_io(blkif, &req, pending_req))
+ if (dispatch_rw_block_io(ring, &req, pending_req))
goto done;
break;
case BLKIF_OP_DISCARD:
- free_req(blkif, pending_req);
- if (dispatch_discard_io(blkif, &req))
+ free_req(ring, pending_req);
+ if (dispatch_discard_io(ring, &req))
goto done;
break;
default:
- if (dispatch_other_io(blkif, &req, pending_req))
+ if (dispatch_other_io(ring, &req, pending_req))
goto done;
break;
}
@@ -1107,13 +1126,13 @@ done:
}
static int
-do_block_io_op(struct xen_blkif *blkif)
+do_block_io_op(struct xen_blkif_ring *ring)
{
- union blkif_back_rings *blk_rings = &blkif->blk_rings;
+ union blkif_back_rings *blk_rings = &ring->blk_rings;
int more_to_do;
do {
- more_to_do = __do_block_io_op(blkif);
+ more_to_do = __do_block_io_op(ring);
if (more_to_do)
break;
@@ -1126,7 +1145,7 @@ do_block_io_op(struct xen_blkif *blkif)
* Transmutation of the 'struct blkif_request' to a proper 'struct bio'
* and call the 'submit_bio' to pass it to the underlying storage.
*/
-static int dispatch_rw_block_io(struct xen_blkif *blkif,
+static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
struct blkif_request *req,
struct pending_req *pending_req)
{
@@ -1140,6 +1159,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
struct blk_plug plug;
bool drain = false;
struct grant_page **pages = pending_req->segments;
+ struct xen_blkif *blkif = ring->blkif;
unsigned short req_operation;
req_operation = req->operation == BLKIF_OP_INDIRECT ?
@@ -1152,26 +1172,29 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
goto fail_response;
}
+ spin_lock_irq(&ring->stats_lock);
switch (req_operation) {
case BLKIF_OP_READ:
- blkif->st_rd_req++;
+ ring->st_rd_req++;
operation = READ;
break;
case BLKIF_OP_WRITE:
- blkif->st_wr_req++;
+ ring->st_wr_req++;
operation = WRITE_ODIRECT;
break;
case BLKIF_OP_WRITE_BARRIER:
drain = true;
case BLKIF_OP_FLUSH_DISKCACHE:
- blkif->st_f_req++;
+ ring->st_f_req++;
operation = WRITE_FLUSH;
break;
default:
operation = 0; /* make gcc happy */
+ spin_unlock_irq(&ring->stats_lock);
goto fail_response;
break;
}
+ spin_unlock_irq(&ring->stats_lock);
/* Check that the number of segments is sane. */
nseg = req->operation == BLKIF_OP_INDIRECT ?
@@ -1190,7 +1213,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
preq.nr_sects = 0;
- pending_req->blkif = blkif;
+ pending_req->ring = ring;
pending_req->id = req->u.rw.id;
pending_req->operation = req_operation;
pending_req->status = BLKIF_RSP_OKAY;
@@ -1243,7 +1266,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
* issue the WRITE_FLUSH.
*/
if (drain)
- xen_blk_drain_io(pending_req->blkif);
+ xen_blk_drain_io(pending_req->ring);
/*
* If we have failed at this point, we need to undo the M2P override,
@@ -1255,11 +1278,11 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
goto fail_flush;
/*
- * This corresponding xen_blkif_put is done in __end_block_io_op, or
+ * This corresponding xen_ring_put is done in __end_block_io_op, or
* below (in "!bio") if we are handling a BLKIF_OP_DISCARD.
*/
- xen_blkif_get(blkif);
- atomic_inc(&blkif->inflight);
+ xen_ring_get(ring);
+ atomic_inc(&ring->inflight);
for (i = 0; i < nseg; i++) {
while ((bio == NULL) ||
@@ -1306,20 +1329,22 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
/* Let the I/Os go.. */
blk_finish_plug(&plug);
+ spin_lock_irq(&ring->stats_lock);
if (operation == READ)
- blkif->st_rd_sect += preq.nr_sects;
+ ring->st_rd_sect += preq.nr_sects;
else if (operation & WRITE)
- blkif->st_wr_sect += preq.nr_sects;
+ ring->st_wr_sect += preq.nr_sects;
+ spin_unlock_irq(&ring->stats_lock);
return 0;
fail_flush:
- xen_blkbk_unmap(blkif, pending_req->segments,
+ xen_blkbk_unmap(ring, pending_req->segments,
pending_req->nr_pages);
fail_response:
/* Haven't submitted any bio's yet. */
- make_response(blkif, req->u.rw.id, req_operation, BLKIF_RSP_ERROR);
- free_req(blkif, pending_req);
+ make_response(ring, req->u.rw.id, req_operation, BLKIF_RSP_ERROR);
+ free_req(ring, pending_req);
msleep(1); /* back off a bit */
return -EIO;
@@ -1337,19 +1362,20 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
/*
* Put a response on the ring on how the operation fared.
*/
-static void make_response(struct xen_blkif *blkif, u64 id,
+static void make_response(struct xen_blkif_ring *ring, u64 id,
unsigned short op, int st)
{
struct blkif_response resp;
unsigned long flags;
- union blkif_back_rings *blk_rings = &blkif->blk_rings;
+ union blkif_back_rings *blk_rings = &ring->blk_rings;
+ struct xen_blkif *blkif = ring->blkif;
int notify;
resp.id = id;
resp.operation = op;
resp.status = st;
- spin_lock_irqsave(&blkif->blk_ring_lock, flags);
+ spin_lock_irqsave(&ring->blk_ring_lock, flags);
/* Place on the response ring for the relevant domain. */
switch (blkif->blk_protocol) {
case BLKIF_PROTOCOL_NATIVE:
@@ -1369,9 +1395,9 @@ static void make_response(struct xen_blkif *blkif, u64 id,
}
blk_rings->common.rsp_prod_pvt++;
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blk_rings->common, notify);
- spin_unlock_irqrestore(&blkif->blk_ring_lock, flags);
+ spin_unlock_irqrestore(&ring->blk_ring_lock, flags);
if (notify)
- notify_remote_via_irq(blkif->irq);
+ notify_remote_via_irq(ring->irq);
}
static int __init xen_blkif_init(void)
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index f65b807..f13cb28 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -226,6 +226,7 @@ struct xen_vbd {
struct block_device *bdev;
/* Cached size parameter. */
sector_t size;
+ unsigned int nr_supported_hw_queues;
unsigned int flush_support:1;
unsigned int discard_secure:1;
unsigned int feature_gnt_persistent:1;
@@ -246,6 +247,8 @@ struct backend_info;
/* Number of requests that we can fit in a ring */
#define XEN_BLKIF_REQS 32
+#define XEN_RING_REQS(nr_rings) ((XEN_BLKIF_REQS / nr_rings > 4) ? \
+ XEN_BLKIF_REQS / nr_rings : 4)
struct persistent_gnt {
struct page *page;
@@ -256,32 +259,29 @@ struct persistent_gnt {
struct list_head remove_node;
};
-struct xen_blkif {
- /* Unique identifier for this interface. */
- domid_t domid;
- unsigned int handle;
+struct xen_blkif_ring {
+ union blkif_back_rings blk_rings;
/* Physical parameters of the comms window. */
unsigned int irq;
- /* Comms information. */
- enum blkif_protocol blk_protocol;
- union blkif_back_rings blk_rings;
- void *blk_ring;
- /* The VBD attached to this interface. */
- struct xen_vbd vbd;
- /* Back pointer to the backend_info. */
- struct backend_info *be;
- /* Private fields. */
- spinlock_t blk_ring_lock;
- atomic_t refcnt;
wait_queue_head_t wq;
- /* for barrier (drain) requests */
- struct completion drain_complete;
- atomic_t drain;
- atomic_t inflight;
/* One thread per one blkif. */
struct task_struct *xenblkd;
unsigned int waiting_reqs;
+ void *blk_ring;
+ spinlock_t blk_ring_lock;
+
+ struct work_struct free_work;
+ /* Thread shutdown wait queue. */
+ wait_queue_head_t shutdown_wq;
+
+ /* buffer of free pages to map grant refs */
+ spinlock_t free_pages_lock;
+ int free_pages_num;
+
+ /* used by the kworker that offload work from the persistent purge */
+ struct list_head persistent_purge_list;
+ struct work_struct persistent_purge_work;
/* tree to store persistent grants */
struct rb_root persistent_gnts;
@@ -289,13 +289,6 @@ struct xen_blkif {
atomic_t persistent_gnt_in_use;
unsigned long next_lru;
- /* used by the kworker that offload work from the persistent purge */
- struct list_head persistent_purge_list;
- struct work_struct persistent_purge_work;
-
- /* buffer of free pages to map grant refs */
- spinlock_t free_pages_lock;
- int free_pages_num;
struct list_head free_pages;
/* List of all 'pending_req' available */
@@ -303,20 +296,54 @@ struct xen_blkif {
/* And its spinlock. */
spinlock_t pending_free_lock;
wait_queue_head_t pending_free_wq;
+ atomic_t inflight;
+
+ /* Private fields. */
+ atomic_t refcnt;
+
+ struct xen_blkif *blkif;
+ unsigned ring_index;
+ spinlock_t stats_lock;
/* statistics */
unsigned long st_print;
- unsigned long long st_rd_req;
- unsigned long long st_wr_req;
- unsigned long long st_oo_req;
- unsigned long long st_f_req;
- unsigned long long st_ds_req;
- unsigned long long st_rd_sect;
- unsigned long long st_wr_sect;
+ unsigned long long st_rd_req;
+ unsigned long long st_wr_req;
+ unsigned long long st_oo_req;
+ unsigned long long st_f_req;
+ unsigned long long st_ds_req;
+ unsigned long long st_rd_sect;
+ unsigned long long st_wr_sect;
+};
- struct work_struct free_work;
- /* Thread shutdown wait queue. */
- wait_queue_head_t shutdown_wq;
+struct xen_blkif {
+ /* Unique identifier for this interface. */
+ domid_t domid;
+ unsigned int handle;
+ /* Comms information. */
+ enum blkif_protocol blk_protocol;
+ /* The VBD attached to this interface. */
+ struct xen_vbd vbd;
+ /* Rings for this device */
+ struct xen_blkif_ring *rings;
+ unsigned int allocated_rings;
+ /* Back pointer to the backend_info. */
+ struct backend_info *be;
+
+ /* for barrier (drain) requests */
+ struct completion drain_complete;
+ atomic_t drain;
+
+ atomic_t refcnt;
+
+ /* statistics */
+ unsigned long long st_rd_req;
+ unsigned long long st_wr_req;
+ unsigned long long st_oo_req;
+ unsigned long long st_f_req;
+ unsigned long long st_ds_req;
+ unsigned long long st_rd_sect;
+ unsigned long long st_wr_sect;
};
struct seg_buf {
@@ -338,7 +365,7 @@ struct grant_page {
* response queued for it, with the saved 'id' passed back.
*/
struct pending_req {
- struct xen_blkif *blkif;
+ struct xen_blkif_ring *ring;
u64 id;
int nr_pages;
atomic_t pendcnt;
@@ -357,11 +384,11 @@ struct pending_req {
(_v)->bdev->bd_part->nr_sects : \
get_capacity((_v)->bdev->bd_disk))
-#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
-#define xen_blkif_put(_b) \
+#define xen_ring_get(_r) (atomic_inc(&(_r)->refcnt))
+#define xen_ring_put(_r) \
do { \
- if (atomic_dec_and_test(&(_b)->refcnt)) \
- schedule_work(&(_b)->free_work);\
+ if (atomic_dec_and_test(&(_r)->refcnt)) \
+ schedule_work(&(_r)->free_work);\
} while (0)
struct phys_req {
@@ -377,7 +404,7 @@ int xen_blkif_xenbus_init(void);
irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
int xen_blkif_schedule(void *arg);
int xen_blkif_purge_persistent(void *arg);
-void xen_blkbk_free_caches(struct xen_blkif *blkif);
+void xen_blkbk_free_caches(struct xen_blkif_ring *ring);
int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
struct backend_info *be, int state);
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 3a8b810..89b120c 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -35,7 +35,7 @@ static void connect(struct backend_info *);
static int connect_ring(struct backend_info *);
static void backend_changed(struct xenbus_watch *, const char **,
unsigned int);
-static void xen_blkif_free(struct xen_blkif *blkif);
+static void xen_ring_free(struct xen_blkif_ring *ring);
static void xen_vbd_free(struct xen_vbd *vbd);
struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be)
@@ -45,17 +45,17 @@ struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be)
/*
* The last request could free the device from softirq context and
- * xen_blkif_free() can sleep.
+ * xen_ring_free() can sleep.
*/
-static void xen_blkif_deferred_free(struct work_struct *work)
+static void xen_ring_deferred_free(struct work_struct *work)
{
- struct xen_blkif *blkif;
+ struct xen_blkif_ring *ring;
- blkif = container_of(work, struct xen_blkif, free_work);
- xen_blkif_free(blkif);
+ ring = container_of(work, struct xen_blkif_ring, free_work);
+ xen_ring_free(ring);
}
-static int blkback_name(struct xen_blkif *blkif, char *buf)
+static int blkback_name(struct xen_blkif *blkif, char *buf, bool save_space)
{
char *devpath, *devname;
struct xenbus_device *dev = blkif->be->dev;
@@ -70,7 +70,10 @@ static int blkback_name(struct xen_blkif *blkif, char *buf)
else
devname = devpath;
- snprintf(buf, TASK_COMM_LEN, "blkback.%d.%s", blkif->domid, devname);
+ if (save_space)
+ snprintf(buf, TASK_COMM_LEN, "blkbk.%d.%s", blkif->domid, devname);
+ else
+ snprintf(buf, TASK_COMM_LEN, "blkback.%d.%s", blkif->domid, devname);
kfree(devpath);
return 0;
@@ -78,11 +81,15 @@ static int blkback_name(struct xen_blkif *blkif, char *buf)
static void xen_update_blkif_status(struct xen_blkif *blkif)
{
- int err;
- char name[TASK_COMM_LEN];
+ int i, err;
+ char name[TASK_COMM_LEN], per_ring_name[TASK_COMM_LEN];
+ struct xen_blkif_ring *ring;
- /* Not ready to connect? */
- if (!blkif->irq || !blkif->vbd.bdev)
+ /*
+ * Not ready to connect? Check irq of first ring as the others
+ * should all be the same.
+ */
+ if (!blkif->rings || !blkif->rings[0].irq || !blkif->vbd.bdev)
return;
/* Already connected? */
@@ -94,7 +101,7 @@ static void xen_update_blkif_status(struct xen_blkif *blkif)
if (blkif->be->dev->state != XenbusStateConnected)
return;
- err = blkback_name(blkif, name);
+ err = blkback_name(blkif, name, blkif->vbd.nr_supported_hw_queues);
if (err) {
xenbus_dev_error(blkif->be->dev, err, "get blkback dev name");
return;
@@ -107,20 +114,98 @@ static void xen_update_blkif_status(struct xen_blkif *blkif)
}
invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping);
- blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, "%s", name);
- if (IS_ERR(blkif->xenblkd)) {
- err = PTR_ERR(blkif->xenblkd);
- blkif->xenblkd = NULL;
- xenbus_dev_error(blkif->be->dev, err, "start xenblkd");
- return;
+ for (i = 0 ; i < blkif->allocated_rings ; i++) {
+ ring = &blkif->rings[i];
+ if (blkif->vbd.nr_supported_hw_queues)
+ snprintf(per_ring_name, TASK_COMM_LEN, "%s-%d", name, i);
+ else {
+ BUG_ON(i != 0);
+ snprintf(per_ring_name, TASK_COMM_LEN, "%s", name);
+ }
+ ring->xenblkd = kthread_run(xen_blkif_schedule, ring, "%s", per_ring_name);
+ if (IS_ERR(ring->xenblkd)) {
+ err = PTR_ERR(ring->xenblkd);
+ ring->xenblkd = NULL;
+ xenbus_dev_error(blkif->be->dev, err, "start %s", per_ring_name);
+ return;
+ }
+ }
+}
+
+static struct xen_blkif_ring *xen_blkif_ring_alloc(struct xen_blkif *blkif,
+ int nr_rings)
+{
+ int r, i, j;
+ struct xen_blkif_ring *rings;
+ struct pending_req *req;
+
+ rings = kzalloc(nr_rings * sizeof(struct xen_blkif_ring),
+ GFP_KERNEL);
+ if (!rings)
+ return NULL;
+
+ for (r = 0 ; r < nr_rings ; r++) {
+ struct xen_blkif_ring *ring = &rings[r];
+
+ spin_lock_init(&ring->blk_ring_lock);
+
+ init_waitqueue_head(&ring->wq);
+ init_waitqueue_head(&ring->shutdown_wq);
+
+ ring->persistent_gnts.rb_node = NULL;
+ spin_lock_init(&ring->free_pages_lock);
+ INIT_LIST_HEAD(&ring->free_pages);
+ INIT_LIST_HEAD(&ring->persistent_purge_list);
+ ring->free_pages_num = 0;
+ atomic_set(&ring->persistent_gnt_in_use, 0);
+ atomic_set(&ring->refcnt, 1);
+ atomic_set(&ring->inflight, 0);
+ INIT_WORK(&ring->persistent_purge_work, xen_blkbk_unmap_purged_grants);
+ spin_lock_init(&ring->pending_free_lock);
+ init_waitqueue_head(&ring->pending_free_wq);
+ INIT_LIST_HEAD(&ring->pending_free);
+ for (i = 0; i < XEN_RING_REQS(nr_rings); i++) {
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ goto fail;
+ list_add_tail(&req->free_list,
+ &ring->pending_free);
+ for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
+ req->segments[j] = kzalloc(sizeof(*req->segments[0]),
+ GFP_KERNEL);
+ if (!req->segments[j])
+ goto fail;
+ }
+ for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
+ req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]),
+ GFP_KERNEL);
+ if (!req->indirect_pages[j])
+ goto fail;
+ }
+ }
+
+ INIT_WORK(&ring->free_work, xen_ring_deferred_free);
+ ring->blkif = blkif;
+ ring->ring_index = r;
+
+ spin_lock_init(&ring->stats_lock);
+ ring->st_print = jiffies;
+
+ atomic_inc(&blkif->refcnt);
}
+
+ blkif->allocated_rings = nr_rings;
+
+ return rings;
+
+fail:
+ kfree(rings);
+ return NULL;
}
static struct xen_blkif *xen_blkif_alloc(domid_t domid)
{
struct xen_blkif *blkif;
- struct pending_req *req, *n;
- int i, j;
BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST);
@@ -129,80 +214,26 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
return ERR_PTR(-ENOMEM);
blkif->domid = domid;
- spin_lock_init(&blkif->blk_ring_lock);
- atomic_set(&blkif->refcnt, 1);
- init_waitqueue_head(&blkif->wq);
init_completion(&blkif->drain_complete);
atomic_set(&blkif->drain, 0);
- blkif->st_print = jiffies;
- blkif->persistent_gnts.rb_node = NULL;
- spin_lock_init(&blkif->free_pages_lock);
- INIT_LIST_HEAD(&blkif->free_pages);
- INIT_LIST_HEAD(&blkif->persistent_purge_list);
- blkif->free_pages_num = 0;
- atomic_set(&blkif->persistent_gnt_in_use, 0);
- atomic_set(&blkif->inflight, 0);
- INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants);
-
- INIT_LIST_HEAD(&blkif->pending_free);
- INIT_WORK(&blkif->free_work, xen_blkif_deferred_free);
-
- for (i = 0; i < XEN_BLKIF_REQS; i++) {
- req = kzalloc(sizeof(*req), GFP_KERNEL);
- if (!req)
- goto fail;
- list_add_tail(&req->free_list,
- &blkif->pending_free);
- for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
- req->segments[j] = kzalloc(sizeof(*req->segments[0]),
- GFP_KERNEL);
- if (!req->segments[j])
- goto fail;
- }
- for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
- req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]),
- GFP_KERNEL);
- if (!req->indirect_pages[j])
- goto fail;
- }
- }
- spin_lock_init(&blkif->pending_free_lock);
- init_waitqueue_head(&blkif->pending_free_wq);
- init_waitqueue_head(&blkif->shutdown_wq);
return blkif;
-
-fail:
- list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) {
- list_del(&req->free_list);
- for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
- if (!req->segments[j])
- break;
- kfree(req->segments[j]);
- }
- for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
- if (!req->indirect_pages[j])
- break;
- kfree(req->indirect_pages[j]);
- }
- kfree(req);
- }
-
- kmem_cache_free(xen_blkif_cachep, blkif);
-
- return ERR_PTR(-ENOMEM);
}
-static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,
- unsigned int evtchn)
+static int xen_blkif_map(struct xen_blkif_ring *ring, unsigned long shared_page,
+ unsigned int evtchn, unsigned int ring_idx)
{
int err;
+ struct xen_blkif *blkif;
+ char dev_name[64];
/* Already connected through? */
- if (blkif->irq)
+ if (ring->irq)
return 0;
- err = xenbus_map_ring_valloc(blkif->be->dev, shared_page, &blkif->blk_ring);
+ blkif = ring->blkif;
+
+ err = xenbus_map_ring_valloc(ring->blkif->be->dev, shared_page, &ring->blk_ring);
if (err < 0)
return err;
@@ -210,64 +241,73 @@ static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,
case BLKIF_PROTOCOL_NATIVE:
{
struct blkif_sring *sring;
- sring = (struct blkif_sring *)blkif->blk_ring;
- BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE);
+ sring = (struct blkif_sring *)ring->blk_ring;
+ BACK_RING_INIT(&ring->blk_rings.native, sring, PAGE_SIZE);
break;
}
case BLKIF_PROTOCOL_X86_32:
{
struct blkif_x86_32_sring *sring_x86_32;
- sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring;
- BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
+ sring_x86_32 = (struct blkif_x86_32_sring *)ring->blk_ring;
+ BACK_RING_INIT(&ring->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
break;
}
case BLKIF_PROTOCOL_X86_64:
{
struct blkif_x86_64_sring *sring_x86_64;
- sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring;
- BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
+ sring_x86_64 = (struct blkif_x86_64_sring *)ring->blk_ring;
+ BACK_RING_INIT(&ring->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
break;
}
default:
BUG();
}
+ if (blkif->vbd.nr_supported_hw_queues)
+ snprintf(dev_name, 64, "blkif-backend-%d", ring_idx);
+ else
+ snprintf(dev_name, 64, "blkif-backend");
err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn,
xen_blkif_be_int, 0,
- "blkif-backend", blkif);
+ dev_name, ring);
if (err < 0) {
- xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring);
- blkif->blk_rings.common.sring = NULL;
+ xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring);
+ ring->blk_rings.common.sring = NULL;
return err;
}
- blkif->irq = err;
+ ring->irq = err;
return 0;
}
static int xen_blkif_disconnect(struct xen_blkif *blkif)
{
- if (blkif->xenblkd) {
- kthread_stop(blkif->xenblkd);
- wake_up(&blkif->shutdown_wq);
- blkif->xenblkd = NULL;
- }
+ int i;
+
+ for (i = 0 ; i < blkif->allocated_rings ; i++) {
+ struct xen_blkif_ring *ring = &blkif->rings[i];
+ if (ring->xenblkd) {
+ kthread_stop(ring->xenblkd);
+ wake_up(&ring->shutdown_wq);
+ ring->xenblkd = NULL;
+ }
- /* The above kthread_stop() guarantees that at this point we
- * don't have any discard_io or other_io requests. So, checking
- * for inflight IO is enough.
- */
- if (atomic_read(&blkif->inflight) > 0)
- return -EBUSY;
+ /* The above kthread_stop() guarantees that at this point we
+ * don't have any discard_io or other_io requests. So, checking
+ * for inflight IO is enough.
+ */
+ if (atomic_read(&ring->inflight) > 0)
+ return -EBUSY;
- if (blkif->irq) {
- unbind_from_irqhandler(blkif->irq, blkif);
- blkif->irq = 0;
- }
+ if (ring->irq) {
+ unbind_from_irqhandler(ring->irq, ring);
+ ring->irq = 0;
+ }
- if (blkif->blk_rings.common.sring) {
- xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring);
- blkif->blk_rings.common.sring = NULL;
+ if (ring->blk_rings.common.sring) {
+ xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring);
+ ring->blk_rings.common.sring = NULL;
+ }
}
return 0;
@@ -275,40 +315,52 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
static void xen_blkif_free(struct xen_blkif *blkif)
{
- struct pending_req *req, *n;
- int i = 0, j;
xen_blkif_disconnect(blkif);
xen_vbd_free(&blkif->vbd);
+ kfree(blkif->rings);
+
+ kmem_cache_free(xen_blkif_cachep, blkif);
+}
+
+static void xen_ring_free(struct xen_blkif_ring *ring)
+{
+ struct pending_req *req, *n;
+ int i, j;
+
/* Remove all persistent grants and the cache of ballooned pages. */
- xen_blkbk_free_caches(blkif);
+ xen_blkbk_free_caches(ring);
/* Make sure everything is drained before shutting down */
- BUG_ON(blkif->persistent_gnt_c != 0);
- BUG_ON(atomic_read(&blkif->persistent_gnt_in_use) != 0);
- BUG_ON(blkif->free_pages_num != 0);
- BUG_ON(!list_empty(&blkif->persistent_purge_list));
- BUG_ON(!list_empty(&blkif->free_pages));
- BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));
-
+ BUG_ON(ring->persistent_gnt_c != 0);
+ BUG_ON(atomic_read(&ring->persistent_gnt_in_use) != 0);
+ BUG_ON(ring->free_pages_num != 0);
+ BUG_ON(!list_empty(&ring->persistent_purge_list));
+ BUG_ON(!list_empty(&ring->free_pages));
+ BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts));
+
+ i = 0;
/* Check that there is no request in use */
- list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) {
+ list_for_each_entry_safe(req, n, &ring->pending_free, free_list) {
list_del(&req->free_list);
-
- for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++)
+ for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
+ if (!req->segments[j])
+ break;
kfree(req->segments[j]);
-
- for (j = 0; j < MAX_INDIRECT_PAGES; j++)
+ }
+ for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
+ if (!req->segments[j])
+ break;
kfree(req->indirect_pages[j]);
-
+ }
kfree(req);
i++;
}
+ WARN_ON(i != XEN_RING_REQS(ring->blkif->allocated_rings));
- WARN_ON(i != XEN_BLKIF_REQS);
-
- kmem_cache_free(xen_blkif_cachep, blkif);
+ if (atomic_dec_and_test(&ring->blkif->refcnt))
+ xen_blkif_free(ring->blkif);
}
int __init xen_blkif_interface_init(void)
@@ -333,6 +385,29 @@ int __init xen_blkif_interface_init(void)
{ \
struct xenbus_device *dev = to_xenbus_device(_dev); \
struct backend_info *be = dev_get_drvdata(&dev->dev); \
+ struct xen_blkif *blkif = be->blkif; \
+ struct xen_blkif_ring *ring; \
+ int i; \
+ \
+ blkif->st_oo_req = 0; \
+ blkif->st_rd_req = 0; \
+ blkif->st_wr_req = 0; \
+ blkif->st_f_req = 0; \
+ blkif->st_ds_req = 0; \
+ blkif->st_rd_sect = 0; \
+ blkif->st_wr_sect = 0; \
+ for (i = 0 ; i < blkif->allocated_rings ; i++) { \
+ ring = &blkif->rings[i]; \
+ spin_lock_irq(&ring->stats_lock); \
+ blkif->st_oo_req += ring->st_oo_req; \
+ blkif->st_rd_req += ring->st_rd_req; \
+ blkif->st_wr_req += ring->st_wr_req; \
+ blkif->st_f_req += ring->st_f_req; \
+ blkif->st_ds_req += ring->st_ds_req; \
+ blkif->st_rd_sect += ring->st_rd_sect; \
+ blkif->st_wr_sect += ring->st_wr_sect; \
+ spin_unlock_irq(&ring->stats_lock); \
+ } \
\
return sprintf(buf, format, ##args); \
} \
@@ -404,6 +479,34 @@ static void xen_vbd_free(struct xen_vbd *vbd)
vbd->bdev = NULL;
}
+static int xen_advertise_hw_queues(struct xen_blkif *blkif,
+ struct request_queue *q)
+{
+ struct xen_vbd *vbd = &blkif->vbd;
+ struct xenbus_transaction xbt;
+ int err;
+
+ if (q && q->mq_ops)
+ vbd->nr_supported_hw_queues = q->nr_hw_queues;
+
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ BUG_ON(!blkif->be);
+ xenbus_dev_fatal(blkif->be->dev, err, "starting transaction (hw queues)");
+ return err;
+ }
+
+ err = xenbus_printf(xbt, blkif->be->dev->nodename, "nr_supported_hw_queues", "%u",
+ blkif->vbd.nr_supported_hw_queues);
+ if (err)
+ xenbus_dev_error(blkif->be->dev, err, "writing %s/nr_supported_hw_queues",
+ blkif->be->dev->nodename);
+
+ xenbus_transaction_end(xbt, 0);
+
+ return err;
+}
+
static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
unsigned major, unsigned minor, int readonly,
int cdrom)
@@ -411,6 +514,7 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
struct xen_vbd *vbd;
struct block_device *bdev;
struct request_queue *q;
+ int err;
vbd = &blkif->vbd;
vbd->handle = handle;
@@ -449,10 +553,15 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
if (q && blk_queue_secdiscard(q))
vbd->discard_secure = true;
+ err = xen_advertise_hw_queues(blkif, q);
+ if (err)
+ return -ENOENT;
+
DPRINTK("Successful creation of handle=%04x (dom=%u)\n",
handle, blkif->domid);
return 0;
}
+
static int xen_blkbk_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
@@ -468,13 +577,14 @@ static int xen_blkbk_remove(struct xenbus_device *dev)
be->backend_watch.node = NULL;
}
- dev_set_drvdata(&dev->dev, NULL);
-
if (be->blkif) {
+ int i = 0;
xen_blkif_disconnect(be->blkif);
- xen_blkif_put(be->blkif);
+ for (; i < be->blkif->allocated_rings ; i++)
+ xen_ring_put(&be->blkif->rings[i]);
}
+ dev_set_drvdata(&dev->dev, NULL);
kfree(be->mode);
kfree(be);
return 0;
@@ -851,21 +961,55 @@ again:
static int connect_ring(struct backend_info *be)
{
struct xenbus_device *dev = be->dev;
- unsigned long ring_ref;
- unsigned int evtchn;
+ struct xen_blkif *blkif = be->blkif;
+ unsigned long *ring_ref;
+ unsigned int *evtchn;
unsigned int pers_grants;
- char protocol[64] = "";
- int err;
+ char protocol[64] = "", ring_ref_s[64] = "", evtchn_s[64] = "";
+ int i, err;
+ bool retry = false;
DPRINTK("%s", dev->otherend);
- err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu",
- &ring_ref, "event-channel", "%u", &evtchn, NULL);
- if (err) {
- xenbus_dev_fatal(dev, err,
- "reading %s/ring-ref and event-channel",
- dev->otherend);
- return err;
+#define BLKIF_NR_RINGS(blkif) (blkif->vbd.nr_supported_hw_queues ? : 1)
+
+ ring_ref = kzalloc(sizeof(unsigned long) * BLKIF_NR_RINGS(blkif),
+ GFP_KERNEL);
+ if (!ring_ref)
+ return -ENOMEM;
+ evtchn = kzalloc(sizeof(unsigned int) * BLKIF_NR_RINGS(blkif),
+ GFP_KERNEL);
+ if (!evtchn) {
+ kfree(ring_ref);
+ return -ENOMEM;
+ }
+
+retry:
+ if (retry)
+ blkif->vbd.nr_supported_hw_queues = 0;
+ for (i = 0 ; i < BLKIF_NR_RINGS(blkif) ; i++) {
+ if (blkif->vbd.nr_supported_hw_queues == 0) {
+ BUG_ON(i != 0);
+ /* Support old XenStore keys for compatibility */
+ snprintf(ring_ref_s, 64, "ring-ref");
+ snprintf(evtchn_s, 64, "event-channel");
+ } else {
+ snprintf(ring_ref_s, 64, "ring-ref-%d", i);
+ snprintf(evtchn_s, 64, "event-channel-%d", i);
+ }
+ err = xenbus_gather(XBT_NIL, dev->otherend,
+ ring_ref_s, "%lu", &ring_ref[i],
+ evtchn_s, "%u", &evtchn[i], NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/%s and event-channel",
+ dev->otherend, ring_ref_s);
+ if (i == 0 && blkif->vbd.nr_supported_hw_queues) {
+ retry = true;
+ goto retry;
+ }
+ goto fail;
+ }
}
be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE;
@@ -881,7 +1025,8 @@ static int connect_ring(struct backend_info *be)
be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64;
else {
xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
- return -1;
+ err = -1;
+ goto fail;
}
err = xenbus_gather(XBT_NIL, dev->otherend,
"feature-persistent", "%u",
@@ -892,19 +1037,39 @@ static int connect_ring(struct backend_info *be)
be->blkif->vbd.feature_gnt_persistent = pers_grants;
be->blkif->vbd.overflow_max_grants = 0;
- pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
- ring_ref, evtchn, be->blkif->blk_protocol, protocol,
- pers_grants ? "persistent grants" : "");
-
- /* Map the shared frame, irq etc. */
- err = xen_blkif_map(be->blkif, ring_ref, evtchn);
- if (err) {
- xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u",
- ring_ref, evtchn);
- return err;
+ blkif->rings = xen_blkif_ring_alloc(blkif, BLKIF_NR_RINGS(blkif));
+ if (!blkif->rings) {
+ err = -ENOMEM;
+ goto fail;
+ }
+ /* Enforce postcondition on number of allocated rings */
+ BUG_ON(blkif->vbd.nr_supported_hw_queues ?
+ blkif->vbd.nr_supported_hw_queues != blkif->allocated_rings :
+ blkif->allocated_rings != 1);
+
+ for (i = 0; i < blkif->allocated_rings ; i++) {
+ pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
+ ring_ref[i], evtchn[i], blkif->blk_protocol, protocol,
+ pers_grants ? "persistent grants" : "");
+
+ /* Map the shared frame, irq etc. */
+ err = xen_blkif_map(&blkif->rings[i], ring_ref[i], evtchn[i], i);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u of ring %d",
+ ring_ref[i], evtchn[i], i);
+ goto fail;
+ }
}
+ kfree(ring_ref);
+ kfree(evtchn);
+
return 0;
+
+fail:
+ kfree(ring_ref);
+ kfree(evtchn);
+ return err;
}
--
2.0.4
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