[PATCH v5 02/10] xen/blkfront: separate per ring information out of device info

From: Bob Liu
Date: Fri Nov 13 2015 - 22:14:20 EST

Split per ring information to an new structure "blkfront_ring_info".

A ring is the representation of a hardware queue, every vbd device can associate
with one or more rings depending on how many hardware queues/rings to be used.

This patch is a preparation for supporting real multi hardware queues/rings.

Signed-off-by: Arianna Avanzini <avanzini.arianna@xxxxxxxxx>
Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
---
v2: Fix build error.
---
drivers/block/xen-blkfront.c | 359 +++++++++++++++++++++++-------------------
1 file changed, 197 insertions(+), 162 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2fee2ee..0c3ad21 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -120,6 +120,23 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
#define RINGREF_NAME_LEN (20)

/*
+ * Per-ring info.
+ * Every blkfront device can associate with one or more blkfront_ring_info,
+ * depending on how many hardware queues/rings to be used.
+ */
+struct blkfront_ring_info {
+ struct blkif_front_ring ring;
+ unsigned int ring_ref[XENBUS_MAX_RING_GRANTS];
+ unsigned int evtchn, irq;
+ struct work_struct work;
+ struct gnttab_free_callback callback;
+ struct blk_shadow shadow[BLK_MAX_RING_SIZE];
+ struct list_head indirect_pages;
+ unsigned long shadow_free;
+ struct blkfront_info *dev_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 :-)
@@ -133,18 +150,10 @@ struct blkfront_info
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int ring_ref[XENBUS_MAX_RING_GRANTS];
unsigned int nr_ring_pages;
- struct blkif_front_ring ring;
- unsigned int evtchn, irq;
struct request_queue *rq;
- struct work_struct work;
- struct gnttab_free_callback callback;
- struct blk_shadow shadow[BLK_MAX_RING_SIZE];
struct list_head grants;
- struct list_head indirect_pages;
unsigned int persistent_gnts_c;
- unsigned long shadow_free;
unsigned int feature_flush;
unsigned int feature_discard:1;
unsigned int feature_secdiscard:1;
@@ -155,6 +164,7 @@ 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;
@@ -198,33 +208,35 @@ static DEFINE_SPINLOCK(minor_lock);

#define GREFS(_psegs) ((_psegs) * GRANTS_PER_PSEG)

-static int blkfront_setup_indirect(struct blkfront_info *info);
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
static int blkfront_gather_backend_features(struct blkfront_info *info);

-static int get_id_from_freelist(struct blkfront_info *info)
+static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
{
- unsigned long free = info->shadow_free;
- BUG_ON(free >= BLK_RING_SIZE(info));
- info->shadow_free = info->shadow[free].req.u.rw.id;
- info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
+ unsigned long free = rinfo->shadow_free;
+
+ BUG_ON(free >= BLK_RING_SIZE(rinfo->dev_info));
+ rinfo->shadow_free = rinfo->shadow[free].req.u.rw.id;
+ rinfo->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
return free;
}

-static int add_id_to_freelist(struct blkfront_info *info,
+static int add_id_to_freelist(struct blkfront_ring_info *rinfo,
unsigned long id)
{
- if (info->shadow[id].req.u.rw.id != id)
+ if (rinfo->shadow[id].req.u.rw.id != id)
return -EINVAL;
- if (info->shadow[id].request == NULL)
+ if (rinfo->shadow[id].request == NULL)
return -EINVAL;
- info->shadow[id].req.u.rw.id = info->shadow_free;
- info->shadow[id].request = NULL;
- info->shadow_free = id;
+ rinfo->shadow[id].req.u.rw.id = rinfo->shadow_free;
+ rinfo->shadow[id].request = NULL;
+ rinfo->shadow_free = id;
return 0;
}

-static int fill_grant_buffer(struct blkfront_info *info, int num)
+static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num)
{
+ struct blkfront_info *info = rinfo->dev_info;
struct page *granted_page;
struct grant *gnt_list_entry, *n;
int i = 0;
@@ -326,8 +338,8 @@ static struct grant *get_indirect_grant(grant_ref_t *gref_head,
struct page *indirect_page;

/* Fetch a pre-allocated page to use for indirect grefs */
- BUG_ON(list_empty(&info->indirect_pages));
- indirect_page = list_first_entry(&info->indirect_pages,
+ BUG_ON(list_empty(&info->rinfo.indirect_pages));
+ indirect_page = list_first_entry(&info->rinfo.indirect_pages,
struct page, lru);
list_del(&indirect_page->lru);
gnt_list_entry->page = indirect_page;
@@ -403,8 +415,8 @@ static void xlbd_release_minors(unsigned int minor, unsigned int nr)

static void blkif_restart_queue_callback(void *arg)
{
- struct blkfront_info *info = (struct blkfront_info *)arg;
- schedule_work(&info->work);
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)arg;
+ schedule_work(&rinfo->work);
}

static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg)
@@ -456,16 +468,16 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
return 0;
}

-static int blkif_queue_discard_req(struct request *req)
+static int blkif_queue_discard_req(struct request *req, struct blkfront_ring_info *rinfo)
{
- struct blkfront_info *info = req->rq_disk->private_data;
+ struct blkfront_info *info = rinfo->dev_info;
struct blkif_request *ring_req;
unsigned long id;

/* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
- id = get_id_from_freelist(info);
- info->shadow[id].request = req;
+ ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt);
+ id = get_id_from_freelist(rinfo);
+ rinfo->shadow[id].request = req;

ring_req->operation = BLKIF_OP_DISCARD;
ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
@@ -476,10 +488,10 @@ static int blkif_queue_discard_req(struct request *req)
else
ring_req->u.discard.flag = 0;

- 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;

return 0;
}
@@ -487,7 +499,7 @@ static int blkif_queue_discard_req(struct request *req)
struct setup_rw_req {
unsigned int grant_idx;
struct blkif_request_segment *segments;
- struct blkfront_info *info;
+ struct blkfront_ring_info *rinfo;
struct blkif_request *ring_req;
grant_ref_t gref_head;
unsigned int id;
@@ -507,8 +519,9 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
/* Convenient aliases */
unsigned int grant_idx = setup->grant_idx;
struct blkif_request *ring_req = setup->ring_req;
- struct blkfront_info *info = setup->info;
- struct blk_shadow *shadow = &info->shadow[setup->id];
+ struct blkfront_ring_info *rinfo = setup->rinfo;
+ struct blkfront_info *info = rinfo->dev_info;
+ struct blk_shadow *shadow = &rinfo->shadow[setup->id];

if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
(grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) {
@@ -566,16 +579,16 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
(setup->grant_idx)++;
}

-static int blkif_queue_rw_req(struct request *req)
+static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo)
{
- struct blkfront_info *info = req->rq_disk->private_data;
+ struct blkfront_info *info = rinfo->dev_info;
struct blkif_request *ring_req;
unsigned long id;
int i;
struct setup_rw_req setup = {
.grant_idx = 0,
.segments = NULL,
- .info = info,
+ .rinfo = rinfo,
.need_copy = rq_data_dir(req) && info->feature_persistent,
};

@@ -603,9 +616,9 @@ static int blkif_queue_rw_req(struct request *req)
max_grefs - info->persistent_gnts_c,
&setup.gref_head) < 0) {
gnttab_request_free_callback(
- &info->callback,
+ &rinfo->callback,
blkif_restart_queue_callback,
- info,
+ rinfo,
max_grefs);
return 1;
}
@@ -613,23 +626,23 @@ static int blkif_queue_rw_req(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;

BUG_ON(info->max_indirect_segments == 0 &&
GREFS(req->nr_phys_segments) > BLKIF_MAX_SEGMENTS_PER_REQUEST);
BUG_ON(info->max_indirect_segments &&
GREFS(req->nr_phys_segments) > info->max_indirect_segments);

- num_sg = blk_rq_map_sg(req->q, req, info->shadow[id].sg);
+ num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
num_grant = 0;
/* Calculate the number of grant used */
- for_each_sg(info->shadow[id].sg, sg, num_sg, i)
+ for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i)
num_grant += gnttab_count_grant(sg->offset, sg->length);

ring_req->u.rw.id = id;
- info->shadow[id].num_sg = num_sg;
+ rinfo->shadow[id].num_sg = num_sg;
if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
/*
* The indirect operation can only be a BLKIF_OP_READ or
@@ -674,7 +687,7 @@ static int blkif_queue_rw_req(struct request *req)

setup.ring_req = ring_req;
setup.id = id;
- for_each_sg(info->shadow[id].sg, sg, num_sg, i) {
+ for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);

if (setup.need_copy) {
@@ -694,10 +707,10 @@ static int blkif_queue_rw_req(struct request *req)
if (setup.segments)
kunmap_atomic(setup.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(setup.gref_head);
@@ -711,27 +724,25 @@ static int blkif_queue_rw_req(struct request *req)
*
* @req: a request struct
*/
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_request(struct request *req, struct blkfront_ring_info *rinfo)
{
- struct blkfront_info *info = req->rq_disk->private_data;
-
- if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
+ if (unlikely(rinfo->dev_info->connected != BLKIF_STATE_CONNECTED))
return 1;

if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE)))
- return blkif_queue_discard_req(req);
+ return blkif_queue_discard_req(req, rinfo);
else
- return blkif_queue_rw_req(req);
+ return blkif_queue_rw_req(req, rinfo);
}

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

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

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

static inline bool blkif_request_flush_invalid(struct request *req,
@@ -747,20 +758,21 @@ static inline bool blkif_request_flush_invalid(struct request *req,
static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
- struct blkfront_info *info = qd->rq->rq_disk->private_data;
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;
+ struct blkfront_info *info = rinfo->dev_info;

blk_mq_start_request(qd->rq);
spin_lock_irq(&info->io_lock);
- if (RING_FULL(&info->ring))
+ if (RING_FULL(&rinfo->ring))
goto out_busy;

- if (blkif_request_flush_invalid(qd->rq, info))
+ if (blkif_request_flush_invalid(qd->rq, rinfo->dev_info))
goto out_err;

- if (blkif_queue_request(qd->rq))
+ if (blkif_queue_request(qd->rq, rinfo))
goto out_busy;

- flush_requests(info);
+ flush_requests(rinfo);
spin_unlock_irq(&info->io_lock);
return BLK_MQ_RQ_QUEUE_OK;

@@ -774,9 +786,19 @@ out_busy:
return BLK_MQ_RQ_QUEUE_BUSY;
}

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

static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
@@ -1029,6 +1051,7 @@ 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;
@@ -1037,10 +1060,10 @@ 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);

@@ -1057,20 +1080,20 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
}

/* Must be called with io_lock holded */
-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))
- blk_mq_start_stopped_hw_queues(info->rq, true);
+ if (!RING_FULL(&rinfo->ring))
+ blk_mq_start_stopped_hw_queues(rinfo->dev_info->rq, true);
}

static void blkif_restart_queue(struct work_struct *work)
{
- struct blkfront_info *info = container_of(work, struct blkfront_info, work);
+ struct blkfront_ring_info *rinfo = container_of(work, struct blkfront_ring_info, work);

- spin_lock_irq(&info->io_lock);
- if (info->connected == BLKIF_STATE_CONNECTED)
- kick_pending_request_queues(info);
- spin_unlock_irq(&info->io_lock);
+ spin_lock_irq(&rinfo->dev_info->io_lock);
+ if (rinfo->dev_info->connected == BLKIF_STATE_CONNECTED)
+ kick_pending_request_queues(rinfo);
+ spin_unlock_irq(&rinfo->dev_info->io_lock);
}

static void blkif_free(struct blkfront_info *info, int suspend)
@@ -1078,6 +1101,7 @@ 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. */
spin_lock_irq(&info->io_lock);
@@ -1090,7 +1114,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
/* Remove all persistent grants */
if (!list_empty(&info->grants)) {
list_for_each_entry_safe(persistent_gnt, n,
- &info->grants, node) {
+ &info->grants, node) {
list_del(&persistent_gnt->node);
if (persistent_gnt->gref != GRANT_INVALID_REF) {
gnttab_end_foreign_access(persistent_gnt->gref,
@@ -1108,11 +1132,11 @@ static void blkif_free(struct blkfront_info *info, int suspend)
* 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);
}
@@ -1123,21 +1147,21 @@ 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(persistent_gnt->page);
kfree(persistent_gnt);
}

- if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT)
+ if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT)
/*
* If this is not an indirect operation don't try to
* free indirect segments
@@ -1145,41 +1169,41 @@ static void blkif_free(struct blkfront_info *info, int suspend)
goto free_shadow;

for (j = 0; j < INDIRECT_GREFS(segs); j++) {
- persistent_gnt = info->shadow[i].indirect_grants[j];
+ persistent_gnt = rinfo->shadow[i].indirect_grants[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
__free_page(persistent_gnt->page);
kfree(persistent_gnt);
}

free_shadow:
- kfree(info->shadow[i].grants_used);
- info->shadow[i].grants_used = NULL;
- kfree(info->shadow[i].indirect_grants);
- info->shadow[i].indirect_grants = NULL;
- kfree(info->shadow[i].sg);
- info->shadow[i].sg = NULL;
+ kfree(rinfo->shadow[i].grants_used);
+ rinfo->shadow[i].grants_used = NULL;
+ kfree(rinfo->shadow[i].indirect_grants);
+ rinfo->shadow[i].indirect_grants = NULL;
+ kfree(rinfo->shadow[i].sg);
+ rinfo->shadow[i].sg = NULL;
}

/* No more gnttab callback work. */
- gnttab_cancel_free_callback(&info->callback);
+ gnttab_cancel_free_callback(&rinfo->callback);
spin_unlock_irq(&info->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. */
for (i = 0; i < info->nr_ring_pages; i++) {
- if (info->ring_ref[i] != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(info->ring_ref[i], 0, 0);
- info->ring_ref[i] = GRANT_INVALID_REF;
+ if (rinfo->ring_ref[i] != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(rinfo->ring_ref[i], 0, 0);
+ rinfo->ring_ref[i] = GRANT_INVALID_REF;
}
}
- free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
- info->ring.sring = NULL;
+ free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
+ rinfo->ring.sring = NULL;

- if (info->irq)
- unbind_from_irqhandler(info->irq, info);
- info->evtchn = info->irq = 0;
+ if (rinfo->irq)
+ unbind_from_irqhandler(rinfo->irq, rinfo);
+ rinfo->evtchn = rinfo->irq = 0;

}

@@ -1209,12 +1233,13 @@ static void blkif_copy_from_grant(unsigned long gfn, unsigned int offset,
kunmap_atomic(shared_data);
}

-static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
+static void blkif_completion(struct blk_shadow *s, struct blkfront_ring_info *rinfo,
struct blkif_response *bret)
{
int i = 0;
struct scatterlist *sg;
int num_sg, num_grant;
+ struct blkfront_info *info = rinfo->dev_info;
struct copy_from_grant data = {
.s = s,
.grant_idx = 0,
@@ -1284,7 +1309,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
*/
if (!info->feature_persistent) {
indirect_page = s->indirect_grants[i]->page;
- list_add(&indirect_page->lru, &info->indirect_pages);
+ list_add(&indirect_page->lru, &rinfo->indirect_pages);
}
s->indirect_grants[i]->gref = GRANT_INVALID_REF;
list_add_tail(&s->indirect_grants[i]->node, &info->grants);
@@ -1299,7 +1324,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
struct blkif_response *bret;
RING_IDX i, rp;
unsigned long flags;
- struct blkfront_info *info = (struct blkfront_info *)dev_id;
+ struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
+ struct blkfront_info *info = rinfo->dev_info;
int error;

spin_lock_irqsave(&info->io_lock, flags);
@@ -1310,13 +1336,13 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
}

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

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

- bret = RING_GET_RESPONSE(&info->ring, i);
+ bret = RING_GET_RESPONSE(&rinfo->ring, i);
id = bret->id;
/*
* The backend has messed up and given us an id that we would
@@ -1330,12 +1356,12 @@ 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;
@@ -1364,7 +1390,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
error = -EOPNOTSUPP;
}
if (unlikely(bret->status == BLKIF_RSP_ERROR &&
- info->shadow[id].req.u.rw.nr_segments == 0)) {
+ rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
info->gd->disk_name, op_name(bret->operation));
error = -EOPNOTSUPP;
@@ -1389,17 +1415,17 @@ 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);

@@ -1408,15 +1434,16 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)


static int setup_blkring(struct xenbus_device *dev,
- struct blkfront_info *info)
+ struct blkfront_ring_info *rinfo)
{
struct blkif_sring *sring;
int err, i;
+ struct blkfront_info *info = rinfo->dev_info;
unsigned long ring_size = info->nr_ring_pages * XEN_PAGE_SIZE;
grant_ref_t gref[XENBUS_MAX_RING_GRANTS];

for (i = 0; i < info->nr_ring_pages; i++)
- info->ring_ref[i] = GRANT_INVALID_REF;
+ rinfo->ring_ref[i] = GRANT_INVALID_REF;

sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
get_order(ring_size));
@@ -1425,29 +1452,29 @@ static int setup_blkring(struct xenbus_device *dev,
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, ring_size);
+ FRONT_RING_INIT(&rinfo->ring, sring, ring_size);

- err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref);
+ err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
if (err < 0) {
free_pages((unsigned long)sring, get_order(ring_size));
- info->ring.sring = NULL;
+ rinfo->ring.sring = NULL;
goto fail;
}
for (i = 0; i < info->nr_ring_pages; i++)
- info->ring_ref[i] = gref[i];
+ rinfo->ring_ref[i] = gref[i];

- err = xenbus_alloc_evtchn(dev, &info->evtchn);
+ err = xenbus_alloc_evtchn(dev, &rinfo->evtchn);
if (err)
goto fail;

- err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0,
- "blkif", info);
+ err = bind_evtchn_to_irqhandler(rinfo->evtchn, blkif_interrupt, 0,
+ "blkif", rinfo);
if (err <= 0) {
xenbus_dev_fatal(dev, err,
"bind_evtchn_to_irqhandler failed");
goto fail;
}
- info->irq = err;
+ rinfo->irq = err;

return 0;
fail:
@@ -1465,6 +1492,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
int err, i;
unsigned int max_page_order = 0;
unsigned int ring_page_order = 0;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
"max-ring-page-order", "%u", &max_page_order);
@@ -1476,7 +1504,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
}

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

@@ -1489,7 +1517,7 @@ again:

if (info->nr_ring_pages == 1) {
err = xenbus_printf(xbt, dev->nodename,
- "ring-ref", "%u", info->ring_ref[0]);
+ "ring-ref", "%u", rinfo->ring_ref[0]);
if (err) {
message = "writing ring-ref";
goto abort_transaction;
@@ -1507,7 +1535,7 @@ again:

snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
- "%u", info->ring_ref[i]);
+ "%u", rinfo->ring_ref[i]);
if (err) {
message = "writing ring-ref";
goto abort_transaction;
@@ -1515,7 +1543,7 @@ again:
}
}
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;
@@ -1541,8 +1569,8 @@ again:
}

for (i = 0; i < BLK_RING_SIZE(info); i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
xenbus_switch_state(dev, XenbusStateInitialised);

return 0;
@@ -1568,6 +1596,7 @@ static int blkfront_probe(struct xenbus_device *dev,
{
int err, vdevice;
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,
@@ -1617,15 +1646,18 @@ static int blkfront_probe(struct xenbus_device *dev,
return -ENOMEM;
}

+ rinfo = &info->rinfo;
+ INIT_LIST_HEAD(&rinfo->indirect_pages);
+ rinfo->dev_info = info;
+ INIT_WORK(&rinfo->work, blkif_restart_queue);
+
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);

/* Front end dir is a number, which is used as the id. */
info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
@@ -1659,19 +1691,20 @@ 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(info); i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow_free = info->ring.req_prod_pvt;
- info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+ rinfo->shadow[i].req.u.rw.id = i+1;
+ rinfo->shadow_free = rinfo->ring.req_prod_pvt;
+ rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;

rc = blkfront_gather_backend_features(info);
if (rc) {
@@ -1717,7 +1750,7 @@ 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) */
@@ -1851,10 +1884,11 @@ 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 psegs, grants;
int err, i;
+ struct blkfront_info *info = rinfo->dev_info;

if (info->max_indirect_segments == 0)
grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
@@ -1862,7 +1896,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
grants = info->max_indirect_segments;
psegs = grants / GRANTS_PER_PSEG;

- err = fill_grant_buffer(info,
+ err = fill_grant_buffer(rinfo,
(grants + INDIRECT_GREFS(grants)) * BLK_RING_SIZE(info));
if (err)
goto out_of_memory;
@@ -1875,31 +1909,31 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
*/
int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info);

- BUG_ON(!list_empty(&info->indirect_pages));
+ BUG_ON(!list_empty(&rinfo->indirect_pages));
for (i = 0; i < num; i++) {
struct page *indirect_page = alloc_page(GFP_NOIO);
if (!indirect_page)
goto out_of_memory;
- list_add(&indirect_page->lru, &info->indirect_pages);
+ list_add(&indirect_page->lru, &rinfo->indirect_pages);
}
}

for (i = 0; i < BLK_RING_SIZE(info); i++) {
- info->shadow[i].grants_used = kzalloc(
- sizeof(info->shadow[i].grants_used[0]) * grants,
+ rinfo->shadow[i].grants_used = kzalloc(
+ sizeof(rinfo->shadow[i].grants_used[0]) * grants,
GFP_NOIO);
- info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * psegs, GFP_NOIO);
+ rinfo->shadow[i].sg = kzalloc(sizeof(rinfo->shadow[i].sg[0]) * psegs, GFP_NOIO);
if (info->max_indirect_segments)
- info->shadow[i].indirect_grants = kzalloc(
- sizeof(info->shadow[i].indirect_grants[0]) *
+ rinfo->shadow[i].indirect_grants = kzalloc(
+ sizeof(rinfo->shadow[i].indirect_grants[0]) *
INDIRECT_GREFS(grants),
GFP_NOIO);
- if ((info->shadow[i].grants_used == NULL) ||
- (info->shadow[i].sg == NULL) ||
+ if ((rinfo->shadow[i].grants_used == NULL) ||
+ (rinfo->shadow[i].sg == NULL) ||
(info->max_indirect_segments &&
- (info->shadow[i].indirect_grants == NULL)))
+ (rinfo->shadow[i].indirect_grants == NULL)))
goto out_of_memory;
- sg_init_table(info->shadow[i].sg, psegs);
+ sg_init_table(rinfo->shadow[i].sg, psegs);
}


@@ -1907,16 +1941,16 @@ static int blkfront_setup_indirect(struct blkfront_info *info)

out_of_memory:
for (i = 0; i < BLK_RING_SIZE(info); i++) {
- kfree(info->shadow[i].grants_used);
- info->shadow[i].grants_used = NULL;
- kfree(info->shadow[i].sg);
- info->shadow[i].sg = NULL;
- kfree(info->shadow[i].indirect_grants);
- info->shadow[i].indirect_grants = NULL;
- }
- if (!list_empty(&info->indirect_pages)) {
+ kfree(rinfo->shadow[i].grants_used);
+ rinfo->shadow[i].grants_used = NULL;
+ kfree(rinfo->shadow[i].sg);
+ rinfo->shadow[i].sg = NULL;
+ kfree(rinfo->shadow[i].indirect_grants);
+ rinfo->shadow[i].indirect_grants = NULL;
+ }
+ if (!list_empty(&rinfo->indirect_pages)) {
struct page *indirect_page, *n;
- list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+ list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
list_del(&indirect_page->lru);
__free_page(indirect_page);
}
@@ -1983,7 +2017,7 @@ static int blkfront_gather_backend_features(struct blkfront_info *info)
info->max_indirect_segments = min(indirect_segments,
xen_blkif_max_segments);

- return blkfront_setup_indirect(info);
+ return blkfront_setup_indirect(&info->rinfo);
}

/*
@@ -1997,6 +2031,7 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned int physical_sector_size;
unsigned int binfo;
int err;
+ struct blkfront_ring_info *rinfo = &info->rinfo;

switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -2073,7 +2108,7 @@ static void blkfront_connect(struct blkfront_info *info)
/* Kick pending requests. */
spin_lock_irq(&info->io_lock);
info->connected = BLKIF_STATE_CONNECTED;
- kick_pending_request_queues(info);
+ kick_pending_request_queues(rinfo);
spin_unlock_irq(&info->io_lock);

add_disk(info->gd);
--
1.7.10.4

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