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Subject[PATCH 04/10] xen/blkfront: separate ring information to an new struct
Date
A ring is the representation of a hardware queue, this patch separate ring
information from blkfront_info to an new struct blkfront_ring_info to make
preparation for real multi hardware queues supporting.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
---
drivers/block/xen-blkfront.c | 403 +++++++++++++++++++++++--------------------
1 file changed, 218 insertions(+), 185 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 5a90a51..aaa4a0e 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -102,23 +102,15 @@ MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default
#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)

/*
- * 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
- * putting all kinds of interesting stuff here :-)
+ * Per-ring info.
+ * A blkfront_info structure can associate with one or more blkfront_ring_info,
+ * depending on how many hardware queues supported.
*/
-struct blkfront_info
-{
+struct blkfront_ring_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;
- struct request_queue *rq;
struct work_struct work;
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
@@ -126,6 +118,22 @@ struct blkfront_info
struct list_head indirect_pages;
unsigned int persistent_gnts_c;
unsigned long shadow_free;
+ struct blkfront_info *info;
+};
+
+/*
+ * 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
+ * putting all kinds of interesting stuff here :-)
+ */
+struct blkfront_info {
+ struct mutex mutex;
+ struct xenbus_device *xbdev;
+ struct gendisk *gd;
+ int vdevice;
+ blkif_vdev_t handle;
+ enum blkif_state connected;
+ struct request_queue *rq;
unsigned int feature_flush;
unsigned int feature_discard:1;
unsigned int feature_secdiscard:1;
@@ -135,6 +143,7 @@ struct blkfront_info
unsigned int max_indirect_segments;
int is_ready;
struct blk_mq_tag_set tag_set;
+ struct blkfront_ring_info rinfo;
};

static unsigned int nr_minors;
@@ -167,34 +176,35 @@ 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_setup_indirect(struct blkfront_ring_info *rinfo);

-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 page *granted_page;
struct grant *gnt_list_entry, *n;
+ struct blkfront_info *info = rinfo->info;
int i = 0;

while(i < num) {
@@ -212,7 +222,7 @@ 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++;
}

@@ -220,7 +230,7 @@ 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));
@@ -232,33 +242,33 @@ out_of_memory:
}

static struct grant *get_grant(grant_ref_t *gref_head,
- unsigned long pfn,
- struct blkfront_info *info)
+ unsigned long pfn,
+ 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,
- buffer_mfn, 0);
+ rinfo->info->xbdev->otherend_id,
+ buffer_mfn, 0);
return gnt_list_entry;
}

@@ -328,8 +338,9 @@ 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)
@@ -387,7 +398,8 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
*
* @req: a request struct
*/
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_request(struct request *req,
+ struct blkfront_ring_info *rinfo)
{
struct blkfront_info *info = req->rq_disk->private_data;
struct blkif_request *ring_req;
@@ -419,15 +431,15 @@ 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;
}
@@ -435,9 +447,9 @@ 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(&rinfo->ring, rinfo->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;
@@ -453,7 +465,7 @@ 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) {
/*
@@ -496,7 +508,7 @@ 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;

@@ -512,22 +524,22 @@ 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;
@@ -573,10 +585,10 @@ static int blkif_queue_request(struct request *req)
kunmap_atomic(segments);
}

- info->ring.req_prod_pvt++;
+ rinfo->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);
@@ -585,14 +597,14 @@ static int blkif_queue_request(struct request *req)
}


-static inline void flush_requests(struct blkfront_info *info)
+static inline void flush_requests(struct blkfront_ring_info *rinfo)
{
int notify;

- RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify);
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&rinfo->ring, notify);

if (notify)
- notify_remote_via_irq(info->irq);
+ notify_remote_via_irq(rinfo->irq);
}

static inline bool blkif_request_flush_invalid(struct request *req,
@@ -608,40 +620,50 @@ static inline bool blkif_request_flush_invalid(struct request *req,
static int blk_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
- struct blkfront_info *info = qd->rq->rq_disk->private_data;
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;
int ret = BLK_MQ_RQ_QUEUE_OK;

blk_mq_start_request(qd->rq);
- spin_lock_irq(&info->io_lock);
- if (RING_FULL(&info->ring)) {
- spin_unlock_irq(&info->io_lock);
+ spin_lock_irq(&rinfo->io_lock);
+ if (RING_FULL(&rinfo->ring)) {
+ spin_unlock_irq(&rinfo->io_lock);
blk_mq_stop_hw_queue(hctx);
ret = BLK_MQ_RQ_QUEUE_BUSY;
goto out;
}

- if (blkif_request_flush_invalid(qd->rq, info)) {
- spin_unlock_irq(&info->io_lock);
+ if (blkif_request_flush_invalid(qd->rq, rinfo->info)) {
+ spin_unlock_irq(&rinfo->io_lock);
ret = BLK_MQ_RQ_QUEUE_ERROR;
goto out;
}

- if (blkif_queue_request(qd->rq)) {
- spin_unlock_irq(&info->io_lock);
+ if (blkif_queue_request(qd->rq, rinfo)) {
+ spin_unlock_irq(&rinfo->io_lock);
blk_mq_stop_hw_queue(hctx);
ret = BLK_MQ_RQ_QUEUE_BUSY;
goto out;
}

- flush_requests(info);
- spin_unlock_irq(&info->io_lock);
+ flush_requests(rinfo);
+ spin_unlock_irq(&rinfo->io_lock);
out:
return ret;
}

+static int blk_mq_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int index)
+{
+ struct blkfront_info *info = (struct blkfront_info *)data;
+
+ hctx->driver_data = &info->rinfo;
+ return 0;
+}
+
static struct blk_mq_ops blkfront_mq_ops = {
.queue_rq = blk_mq_queue_rq,
.map_queue = blk_mq_map_queue,
+ .init_hctx = blk_mq_init_hctx,
};

static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
@@ -894,6 +916,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
static void xlvbd_release_gendisk(struct blkfront_info *info)
{
unsigned int minor, nr_minors;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

if (info->rq == NULL)
return;
@@ -902,10 +925,10 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
blk_mq_stop_hw_queues(info->rq);

/* No more gnttab callback work. */
- gnttab_cancel_free_callback(&info->callback);
+ gnttab_cancel_free_callback(&rinfo->callback);

/* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+ flush_work(&rinfo->work);

del_gendisk(info->gd);

@@ -921,25 +944,25 @@ 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)
{
unsigned long flags;

- spin_lock_irqsave(&info->io_lock, flags);
- if (!RING_FULL(&info->ring)) {
- spin_unlock_irqrestore(&info->io_lock, flags);
- blk_mq_start_stopped_hw_queues(info->rq, true);
+ spin_lock_irqsave(&rinfo->io_lock, flags);
+ if (!RING_FULL(&rinfo->ring)) {
+ spin_unlock_irqrestore(&rinfo->io_lock, flags);
+ blk_mq_start_stopped_hw_queues(rinfo->info->rq, true);
return;
}
- spin_unlock_irqrestore(&info->io_lock, flags);
+ spin_unlock_irqrestore(&rinfo->io_lock, flags);
}

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);

- if (info->connected == BLKIF_STATE_CONNECTED)
- kick_pending_request_queues(info);
+ if (rinfo->info->connected == BLKIF_STATE_CONNECTED)
+ kick_pending_request_queues(rinfo);
}

static void blkif_free(struct blkfront_info *info, int suspend)
@@ -947,6 +970,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
struct grant *persistent_gnt;
struct grant *n;
int i, j, segs;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

/* Prevent new requests being issued until we fix things up. */
info->connected = suspend ?
@@ -955,33 +979,33 @@ static void blkif_free(struct blkfront_info *info, int suspend)
if (info->rq)
blk_mq_stop_hw_queues(info->rq);

- spin_lock_irq(&info->io_lock);
+ spin_lock_irq(&rinfo->io_lock);
/* Remove all persistent grants */
- if (!list_empty(&info->grants)) {
+ if (!list_empty(&rinfo->grants)) {
list_for_each_entry_safe(persistent_gnt, n,
- &info->grants, node) {
+ &rinfo->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--;
+ 0, 0UL);
+ rinfo->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);
+ BUG_ON(rinfo->persistent_gnts_c != 0);

/*
* Remove indirect pages, this only happens when using indirect
* descriptors but not persistent grants
*/
- if (!list_empty(&info->indirect_pages)) {
+ if (!list_empty(&rinfo->indirect_pages)) {
struct page *indirect_page, *n;

BUG_ON(info->feature_persistent);
- list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+ list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
list_del(&indirect_page->lru);
__free_page(indirect_page);
}
@@ -992,21 +1016,21 @@ static void blkif_free(struct blkfront_info *info, int suspend)
* Clear persistent grants present in requests already
* on the shared ring
*/
- if (!info->shadow[i].request)
+ if (!rinfo->shadow[i].request)
goto free_shadow;

- segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
- info->shadow[i].req.u.indirect.nr_segments :
- info->shadow[i].req.u.rw.nr_segments;
+ segs = rinfo->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
+ rinfo->shadow[i].req.u.indirect.nr_segments :
+ rinfo->shadow[i].req.u.rw.nr_segments;
for (j = 0; j < segs; j++) {
- persistent_gnt = info->shadow[i].grants_used[j];
+ persistent_gnt = rinfo->shadow[i].grants_used[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
if (info->feature_persistent)
__free_page(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
@@ -1014,42 +1038,42 @@ 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);
+ gnttab_cancel_free_callback(&rinfo->callback);
+ spin_unlock_irq(&rinfo->io_lock);

/* Flush gnttab callback work. Must be done with no locks held. */
- flush_work(&info->work);
+ flush_work(&rinfo->work);

/* Free resources associated with old device channel. */
- 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;
+ 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 (info->irq)
- unbind_from_irqhandler(info->irq, info);
- info->evtchn = info->irq = 0;
+ if (rinfo->irq)
+ unbind_from_irqhandler(rinfo->irq, rinfo);
+ rinfo->evtchn = rinfo->irq = 0;

}

-static void blkif_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)
{
int i = 0;
@@ -1057,6 +1081,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
char *bvec_data;
void *shared_data;
int nseg;
+ struct blkfront_info *info = rinfo->info;

nseg = s->req.operation == BLKIF_OP_INDIRECT ?
s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments;
@@ -1092,8 +1117,8 @@ 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
@@ -1103,7 +1128,7 @@ 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) {
@@ -1112,8 +1137,8 @@ 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;

@@ -1123,9 +1148,9 @@ 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);
}
}
}
@@ -1137,20 +1162,21 @@ 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;

if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
return IRQ_HANDLED;

- spin_lock_irqsave(&info->io_lock, flags);
+ spin_lock_irqsave(&rinfo->io_lock, flags);
again:
- rp = info->ring.sring->rsp_prod;
+ rp = rinfo->ring.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */

- for (i = info->ring.rsp_cons; i != rp; i++) {
+ for (i = rinfo->ring.rsp_cons; i != rp; i++) {
unsigned long id;

- bret = RING_GET_RESPONSE(&info->ring, i);
+ bret = RING_GET_RESPONSE(&rinfo->ring, i);
id = bret->id;
/*
* The backend has messed up and given us an id that we would
@@ -1164,12 +1190,12 @@ 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;
@@ -1198,7 +1224,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
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));
req->errors = -EOPNOTSUPP;
@@ -1223,30 +1249,30 @@ 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;

- spin_unlock_irqrestore(&info->io_lock, flags);
- kick_pending_request_queues(info);
+ spin_unlock_irqrestore(&rinfo->io_lock, flags);
+ kick_pending_request_queues(rinfo);

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) {
@@ -1254,32 +1280,32 @@ 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;
}

@@ -1291,9 +1317,10 @@ static int talk_to_blkback(struct xenbus_device *dev,
const char *message = NULL;
struct xenbus_transaction xbt;
int err;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

/* Create shared ring, alloc event channel. */
- err = setup_blkring(dev, info);
+ err = setup_blkring(dev, rinfo);
if (err)
goto out;

@@ -1305,13 +1332,13 @@ again:
}

err = xenbus_printf(xbt, dev->nodename,
- "ring-ref", "%u", info->ring_ref);
+ "ring-ref", "%u", rinfo->ring_ref);
if (err) {
message = "writing ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename,
- "event-channel", "%u", info->evtchn);
+ "event-channel", "%u", rinfo->evtchn);
if (err) {
message = "writing event-channel";
goto abort_transaction;
@@ -1361,6 +1388,7 @@ static int blkfront_probe(struct xenbus_device *dev,
{
int err, vdevice, i;
struct blkfront_info *info;
+ struct blkfront_ring_info *rinfo;

/* FIXME: Use dynamic device id if this is not set. */
err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1410,19 +1438,21 @@ static int blkfront_probe(struct xenbus_device *dev,
return -ENOMEM;
}

+ rinfo = &info->rinfo;
mutex_init(&info->mutex);
- spin_lock_init(&info->io_lock);
+ spin_lock_init(&rinfo->io_lock);
info->xbdev = dev;
info->vdevice = vdevice;
- INIT_LIST_HEAD(&info->grants);
- INIT_LIST_HEAD(&info->indirect_pages);
- info->persistent_gnts_c = 0;
+ INIT_LIST_HEAD(&rinfo->grants);
+ INIT_LIST_HEAD(&rinfo->indirect_pages);
+ rinfo->persistent_gnts_c = 0;
info->connected = BLKIF_STATE_DISCONNECTED;
- INIT_WORK(&info->work, blkif_restart_queue);
+ rinfo->info = info;
+ INIT_WORK(&rinfo->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;
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->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);
@@ -1465,21 +1495,22 @@ static int blkif_recover(struct blkfront_info *info)
int pending, size;
struct split_bio *split_bio;
struct list_head requests;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

/* Stage 1: Make a safe copy of the shadow state. */
- copy = kmemdup(info->shadow, sizeof(info->shadow),
+ copy = kmemdup(rinfo->shadow, sizeof(rinfo->shadow),
GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
if (!copy)
return -ENOMEM;

/* Stage 2: Set up free list. */
- memset(&info->shadow, 0, sizeof(info->shadow));
+ memset(&rinfo->shadow, 0, sizeof(rinfo->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;
+ 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;

- rc = blkfront_setup_indirect(info);
+ rc = blkfront_setup_indirect(rinfo);
if (rc) {
kfree(copy);
return rc;
@@ -1521,7 +1552,7 @@ static int blkif_recover(struct blkfront_info *info)
info->connected = BLKIF_STATE_CONNECTED;

/* Kick any other new requests queued since we resumed */
- kick_pending_request_queues(info);
+ kick_pending_request_queues(rinfo);

list_for_each_entry_safe(req, n, &requests, queuelist) {
/* Requeue pending requests (flush or discard) */
@@ -1654,10 +1685,11 @@ static void blkfront_setup_discard(struct blkfront_info *info)
info->feature_secdiscard = !!discard_secure;
}

-static int blkfront_setup_indirect(struct blkfront_info *info)
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
{
unsigned int indirect_segments, segs;
int err, i;
+ struct blkfront_info *info = rinfo->info;

err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
"feature-max-indirect-segments", "%u", &indirect_segments,
@@ -1671,7 +1703,7 @@ 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);
+ err = fill_grant_buffer(rinfo, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
if (err)
goto out_of_memory;

@@ -1683,31 +1715,31 @@ 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);
}


@@ -1715,16 +1747,16 @@ 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);
}
@@ -1744,6 +1776,7 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned int binfo;
int err;
int barrier, flush, discard, persistent;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -1841,7 +1874,7 @@ static void blkfront_connect(struct blkfront_info *info)
else
info->feature_persistent = persistent;

- err = blkfront_setup_indirect(info);
+ err = blkfront_setup_indirect(rinfo);
if (err) {
xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
info->xbdev->otherend);
@@ -1860,7 +1893,7 @@ static void blkfront_connect(struct blkfront_info *info)

/* Kick pending requests. */
info->connected = BLKIF_STATE_CONNECTED;
- kick_pending_request_queues(info);
+ kick_pending_request_queues(rinfo);

add_disk(info->gd);

--
1.8.3.1


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