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Date: Mon, 5 Oct 2015 12:52:47 +0200
From: Roger Pau Monné <roger.pau@...rix.com>
To: Bob Liu <bob.liu@...cle.com>, <xen-devel@...ts.xen.org>
CC: <david.vrabel@...rix.com>, <linux-kernel@...r.kernel.org>,
<konrad.wilk@...cle.com>, <felipe.franciosi@...rix.com>,
<axboe@...com>, <hch@...radead.org>, <avanzini.arianna@...il.com>,
<rafal.mielniczuk@...rix.com>, <boris.ostrovsky@...cle.com>,
<jonathan.davies@...rix.com>
Subject: Re: [PATCH v3 4/9] xen/blkfront: pseudo support for multi hardware
queues/rings
El 05/09/15 a les 14.39, Bob Liu ha escrit:
> Prepare patch for multi hardware queues/rings, the ring number was set to 1 by
> force.
>
> * Use 'nr_rings' in per dev_info to identify how many hw queues/rings are
> supported, and a pointer *rinfo for all its rings.
> * Rename 'nr_ring_pages' => 'pages_per_ring' to distinguish from 'nr_rings'
> better.
>
> Signed-off-by: Bob Liu <bob.liu@...cle.com>
> ---
> drivers/block/xen-blkfront.c | 513 +++++++++++++++++++++++++-----------------
> 1 file changed, 308 insertions(+), 205 deletions(-)
>
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index bf416d5..bf45c99 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -107,7 +107,7 @@ static unsigned int xen_blkif_max_ring_order;
> module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO);
> MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");
>
> -#define BLK_RING_SIZE(dinfo) __CONST_RING_SIZE(blkif, PAGE_SIZE * (dinfo)->nr_ring_pages)
> +#define BLK_RING_SIZE(dinfo) __CONST_RING_SIZE(blkif, PAGE_SIZE * (dinfo)->pages_per_ring)
> #define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE * XENBUS_MAX_RING_PAGES)
> /*
> * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
> @@ -157,9 +157,10 @@ struct blkfront_dev_info {
> unsigned int feature_persistent:1;
> unsigned int max_indirect_segments;
> int is_ready;
> - unsigned int nr_ring_pages;
> + unsigned int pages_per_ring;
Why do you rename this field? nr_ring_pages seems more consistent with
the nr_rings field that you add below IMO, but that might be a matter of
taste.
> struct blk_mq_tag_set tag_set;
> - struct blkfront_ring_info rinfo;
> + struct blkfront_ring_info *rinfo;
> + unsigned int nr_rings;
> };
>
> static unsigned int nr_minors;
> @@ -191,7 +192,7 @@ static DEFINE_SPINLOCK(minor_lock);
> ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
>
> static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
> -static int blkfront_gather_backend_features(struct blkfront_dev_info *dinfo);
> +static void __blkfront_gather_backend_features(struct blkfront_dev_info *dinfo);
>
> static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
> {
> @@ -668,7 +669,7 @@ static int blk_mq_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
> {
> struct blkfront_dev_info *dinfo = (struct blkfront_dev_info *)data;
>
> - hctx->driver_data = &dinfo->rinfo;
> + hctx->driver_data = &dinfo->rinfo[index];
> return 0;
> }
>
> @@ -927,8 +928,8 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
>
> static void xlvbd_release_gendisk(struct blkfront_dev_info *dinfo)
> {
> - unsigned int minor, nr_minors;
> - struct blkfront_ring_info *rinfo = &dinfo->rinfo;
> + unsigned int minor, nr_minors, i;
> + struct blkfront_ring_info *rinfo;
>
> if (dinfo->rq == NULL)
> return;
> @@ -936,11 +937,15 @@ static void xlvbd_release_gendisk(struct blkfront_dev_info *dinfo)
> /* No more blkif_request(). */
> blk_mq_stop_hw_queues(dinfo->rq);
>
> - /* No more gnttab callback work. */
> - gnttab_cancel_free_callback(&rinfo->callback);
> + for (i = 0; i < dinfo->nr_rings; i++) {
I would be tempted to declare rinfo only inside the for loop, to limit
the scope:
struct blkfront_ring_info *rinfo = &dinfo->rinfo[i];
> + rinfo = &dinfo->rinfo[i];
>
> - /* Flush gnttab callback work. Must be done with no locks held. */
> - flush_work(&rinfo->work);
> + /* No more gnttab callback work. */
> + gnttab_cancel_free_callback(&rinfo->callback);
> +
> + /* Flush gnttab callback work. Must be done with no locks held. */
> + flush_work(&rinfo->work);
> + }
>
> del_gendisk(dinfo->gd);
>
> @@ -977,8 +982,8 @@ static void blkif_free(struct blkfront_dev_info *dinfo, int suspend)
> {
> struct grant *persistent_gnt;
> struct grant *n;
> - int i, j, segs;
> - struct blkfront_ring_info *rinfo = &dinfo->rinfo;
> + int i, j, segs, r_index;
> + struct blkfront_ring_info *rinfo;
>
> /* Prevent new requests being issued until we fix things up. */
> spin_lock_irq(&dinfo->io_lock);
> @@ -988,100 +993,103 @@ static void blkif_free(struct blkfront_dev_info *dinfo, int suspend)
> if (dinfo->rq)
> blk_mq_stop_hw_queues(dinfo->rq);
>
> - /* 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--;
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
struct blkfront_ring_info *rinfo = &dinfo->rinfo[r_index];
Would it be helpful to place all this code inside of a helper function,
ie: blkif_free_ring?
> +
> + /* 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 (dinfo->feature_persistent)
> + __free_page(pfn_to_page(persistent_gnt->pfn));
> + kfree(persistent_gnt);
> }
> - if (dinfo->feature_persistent)
> - __free_page(pfn_to_page(persistent_gnt->pfn));
> - kfree(persistent_gnt);
> }
> - }
> - BUG_ON(rinfo->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(&rinfo->indirect_pages)) {
> - struct page *indirect_page, *n;
> -
> - BUG_ON(dinfo->feature_persistent);
> - list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
> - list_del(&indirect_page->lru);
> - __free_page(indirect_page);
> - }
> - }
> -
> - for (i = 0; i < BLK_RING_SIZE(dinfo); i++) {
> /*
> - * Clear persistent grants present in requests already
> - * on the shared ring
> + * Remove indirect pages, this only happens when using indirect
> + * descriptors but not persistent grants
> */
> - if (!rinfo->shadow[i].request)
> - goto free_shadow;
> -
> - 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 = rinfo->shadow[i].grants_used[j];
> - gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
> - if (dinfo->feature_persistent)
> - __free_page(pfn_to_page(persistent_gnt->pfn));
> - kfree(persistent_gnt);
> + if (!list_empty(&rinfo->indirect_pages)) {
> + struct page *indirect_page, *n;
> +
> + BUG_ON(dinfo->feature_persistent);
> + list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
> + list_del(&indirect_page->lru);
> + __free_page(indirect_page);
> + }
> }
>
> - if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT)
> + for (i = 0; i < BLK_RING_SIZE(dinfo); i++) {
> /*
> - * If this is not an indirect operation don't try to
> - * free indirect segments
> + * Clear persistent grants present in requests already
> + * on the shared ring
> */
> - goto free_shadow;
> + if (!rinfo->shadow[i].request)
> + goto free_shadow;
> +
> + 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 = rinfo->shadow[i].grants_used[j];
> + gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
> + if (dinfo->feature_persistent)
> + __free_page(pfn_to_page(persistent_gnt->pfn));
> + kfree(persistent_gnt);
> + }
>
> - for (j = 0; j < INDIRECT_GREFS(segs); 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);
> - }
> + if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT)
> + /*
> + * If this is not an indirect operation don't try to
> + * free indirect segments
> + */
> + goto free_shadow;
> +
> + for (j = 0; j < INDIRECT_GREFS(segs); 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(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;
> - }
> + 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(&rinfo->callback);
> - spin_unlock_irq(&dinfo->io_lock);
> + /* No more gnttab callback work. */
> + gnttab_cancel_free_callback(&rinfo->callback);
> + spin_unlock_irq(&dinfo->io_lock);
>
> - /* Flush gnttab callback work. Must be done with no locks held. */
> - flush_work(&rinfo->work);
> + /* Flush gnttab callback work. Must be done with no locks held. */
> + flush_work(&rinfo->work);
>
> - /* Free resources associated with old device channel. */
> - for (i = 0; i < dinfo->nr_ring_pages; i++) {
> - 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 resources associated with old device channel. */
> + for (i = 0; i < dinfo->pages_per_ring; i++) {
> + 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)rinfo->ring.sring, get_order(dinfo->nr_ring_pages * PAGE_SIZE));
> - rinfo->ring.sring = NULL;
> -
> - if (rinfo->irq)
> - unbind_from_irqhandler(rinfo->irq, rinfo);
> - rinfo->evtchn = rinfo->irq = 0;
> + free_pages((unsigned long)rinfo->ring.sring, get_order(dinfo->pages_per_ring * PAGE_SIZE));
> + rinfo->ring.sring = NULL;
>
> + if (rinfo->irq)
> + unbind_from_irqhandler(rinfo->irq, rinfo);
> + rinfo->evtchn = rinfo->irq = 0;
> + }
> }
>
> static void blkif_completion(struct blk_shadow *s, struct blkfront_ring_info *rinfo,
> @@ -1276,6 +1284,26 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static void destroy_blkring(struct xenbus_device *dev,
> + struct blkfront_ring_info *rinfo)
> +{
> + int i;
> +
> + if (rinfo->irq)
> + unbind_from_irqhandler(rinfo->irq, rinfo);
> + if (rinfo->evtchn)
> + xenbus_free_evtchn(dev, rinfo->evtchn);
> +
> + for (i = 0; i < rinfo->dinfo->pages_per_ring; i++) {
> + 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)rinfo->ring.sring,
> + get_order(rinfo->dinfo->pages_per_ring * PAGE_SIZE));
> + rinfo->ring.sring = NULL;
> +}
>
> static int setup_blkring(struct xenbus_device *dev,
> struct blkfront_ring_info *rinfo)
> @@ -1283,10 +1311,10 @@ static int setup_blkring(struct xenbus_device *dev,
> struct blkif_sring *sring;
> int err, i;
> struct blkfront_dev_info *dinfo = rinfo->dinfo;
> - unsigned long ring_size = dinfo->nr_ring_pages * PAGE_SIZE;
> + unsigned long ring_size = dinfo->pages_per_ring * PAGE_SIZE;
> grant_ref_t gref[XENBUS_MAX_RING_PAGES];
>
> - for (i = 0; i < dinfo->nr_ring_pages; i++)
> + for (i = 0; i < dinfo->pages_per_ring; i++)
> rinfo->ring_ref[i] = GRANT_INVALID_REF;
>
> sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
> @@ -1298,13 +1326,13 @@ static int setup_blkring(struct xenbus_device *dev,
> SHARED_RING_INIT(sring);
> FRONT_RING_INIT(&rinfo->ring, sring, ring_size);
>
> - err = xenbus_grant_ring(dev, rinfo->ring.sring, dinfo->nr_ring_pages, gref);
> + err = xenbus_grant_ring(dev, rinfo->ring.sring, dinfo->pages_per_ring, gref);
> if (err < 0) {
> free_pages((unsigned long)sring, get_order(ring_size));
> rinfo->ring.sring = NULL;
> goto fail;
> }
> - for (i = 0; i < dinfo->nr_ring_pages; i++)
> + for (i = 0; i < dinfo->pages_per_ring; i++)
> rinfo->ring_ref[i] = gref[i];
>
> err = xenbus_alloc_evtchn(dev, &rinfo->evtchn);
> @@ -1322,7 +1350,7 @@ static int setup_blkring(struct xenbus_device *dev,
>
> return 0;
> fail:
> - blkif_free(dinfo, 0);
> + destroy_blkring(dev, rinfo);
blkif_free used to clean a lot more than what destroy_blkring does, is
this right?
> return err;
> }
>
> @@ -1333,65 +1361,76 @@ static int talk_to_blkback(struct xenbus_device *dev,
> {
> const char *message = NULL;
> struct xenbus_transaction xbt;
> - int err, i;
> + int err, i, r_index;
> unsigned int max_page_order = 0;
> unsigned int ring_page_order = 0;
> - struct blkfront_ring_info *rinfo = &dinfo->rinfo;
> + struct blkfront_ring_info *rinfo;
>
> err = xenbus_scanf(XBT_NIL, dinfo->xbdev->otherend,
> "max-ring-page-order", "%u", &max_page_order);
> if (err != 1)
> - dinfo->nr_ring_pages = 1;
> + dinfo->pages_per_ring = 1;
> else {
> ring_page_order = min(xen_blkif_max_ring_order, max_page_order);
> - dinfo->nr_ring_pages = 1 << ring_page_order;
> + dinfo->pages_per_ring = 1 << ring_page_order;
As said above, I think nr_ring_pages is perfectly fine, and avoids all
this ponintless changes.
> }
>
> - /* Create shared ring, alloc event channel. */
> - err = setup_blkring(dev, rinfo);
> - if (err)
> - goto out;
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
> + /* Create shared ring, alloc event channel. */
> + err = setup_blkring(dev, rinfo);
> + if (err)
> + goto out;
> + }
>
> again:
> err = xenbus_transaction_start(&xbt);
> if (err) {
> xenbus_dev_fatal(dev, err, "starting transaction");
> - goto destroy_blkring;
> + goto out;
> }
>
> - if (dinfo->nr_ring_pages == 1) {
> - err = xenbus_printf(xbt, dev->nodename,
> - "ring-ref", "%u", rinfo->ring_ref[0]);
> - if (err) {
> - message = "writing ring-ref";
> - goto abort_transaction;
> - }
> - } else {
> - err = xenbus_printf(xbt, dev->nodename,
> - "ring-page-order", "%u", ring_page_order);
> - if (err) {
> - message = "writing ring-page-order";
> - goto abort_transaction;
> - }
> -
> - for (i = 0; i < dinfo->nr_ring_pages; i++) {
> - char ring_ref_name[RINGREF_NAME_LEN];
> + if (dinfo->nr_rings == 1) {
> + rinfo = &dinfo->rinfo[0];
>
> - snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
> - err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
> - "%u", rinfo->ring_ref[i]);
> + if (dinfo->pages_per_ring == 1) {
> + err = xenbus_printf(xbt, dev->nodename,
> + "ring-ref", "%u", rinfo->ring_ref[0]);
> if (err) {
> message = "writing ring-ref";
> goto abort_transaction;
> }
> + } else {
> + err = xenbus_printf(xbt, dev->nodename,
> + "ring-page-order", "%u", ring_page_order);
> + if (err) {
> + message = "writing ring-page-order";
> + goto abort_transaction;
> + }
> +
> + for (i = 0; i < dinfo->pages_per_ring; i++) {
> + char ring_ref_name[RINGREF_NAME_LEN];
> +
> + snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
> + err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
> + "%u", rinfo->ring_ref[i]);
> + if (err) {
> + message = "writing ring-ref";
> + goto abort_transaction;
> + }
> + }
> }
> - }
> - err = xenbus_printf(xbt, dev->nodename,
> - "event-channel", "%u", rinfo->evtchn);
> - if (err) {
> - message = "writing event-channel";
> + err = xenbus_printf(xbt, dev->nodename,
> + "event-channel", "%u", rinfo->evtchn);
> + if (err) {
> + message = "writing event-channel";
> + goto abort_transaction;
> + }
> + } else {
> + /* Not supported at this stage */
> goto abort_transaction;
> }
> +
> err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
> XEN_IO_PROTO_ABI_NATIVE);
> if (err) {
> @@ -1409,12 +1448,16 @@ again:
> if (err == -EAGAIN)
> goto again;
> xenbus_dev_fatal(dev, err, "completing transaction");
> - goto destroy_blkring;
> + goto out;
> }
>
> - for (i = 0; i < BLK_RING_SIZE(dinfo); i++)
> - rinfo->shadow[i].req.u.rw.id = i+1;
> - rinfo->shadow[BLK_RING_SIZE(dinfo)-1].req.u.rw.id = 0x0fffffff;
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
> +
> + for (i = 0; i < BLK_RING_SIZE(dinfo); i++)
> + rinfo->shadow[i].req.u.rw.id = i+1;
> + rinfo->shadow[BLK_RING_SIZE(dinfo)-1].req.u.rw.id = 0x0fffffff;
> + }
> xenbus_switch_state(dev, XenbusStateInitialised);
>
> return 0;
> @@ -1423,9 +1466,9 @@ again:
> xenbus_transaction_end(xbt, 1);
> if (message)
> xenbus_dev_fatal(dev, err, "%s", message);
> - destroy_blkring:
> - blkif_free(dinfo, 0);
> out:
> + while (--r_index >= 0)
> + destroy_blkring(dev, &dinfo->rinfo[r_index]);
The same as above, destroy_blkring does a different cleaning of what
used to be done in blkif_free.
> return err;
> }
>
> @@ -1438,7 +1481,7 @@ again:
> static int blkfront_probe(struct xenbus_device *dev,
> const struct xenbus_device_id *id)
> {
> - int err, vdevice;
> + int err, vdevice, r_index;
> struct blkfront_dev_info *dinfo;
> struct blkfront_ring_info *rinfo;
>
> @@ -1490,17 +1533,29 @@ static int blkfront_probe(struct xenbus_device *dev,
> return -ENOMEM;
> }
>
> - rinfo = &dinfo->rinfo;
> mutex_init(&dinfo->mutex);
> spin_lock_init(&dinfo->io_lock);
> dinfo->xbdev = dev;
> dinfo->vdevice = vdevice;
> - INIT_LIST_HEAD(&rinfo->grants);
> - INIT_LIST_HEAD(&rinfo->indirect_pages);
> - rinfo->persistent_gnts_c = 0;
> dinfo->connected = BLKIF_STATE_DISCONNECTED;
> - rinfo->dinfo = dinfo;
> - INIT_WORK(&rinfo->work, blkif_restart_queue);
> +
> + dinfo->nr_rings = 1;
> + dinfo->rinfo = kzalloc(sizeof(*rinfo) * dinfo->nr_rings, GFP_KERNEL);
> + if (!dinfo->rinfo) {
> + xenbus_dev_fatal(dev, -ENOMEM, "allocating ring_info structure");
> + kfree(dinfo);
> + return -ENOMEM;
> + }
> +
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
> +
> + INIT_LIST_HEAD(&rinfo->grants);
> + INIT_LIST_HEAD(&rinfo->indirect_pages);
> + rinfo->persistent_gnts_c = 0;
> + rinfo->dinfo = dinfo;
> + INIT_WORK(&rinfo->work, blkif_restart_queue);
> + }
>
> /* Front end dir is a number, which is used as the id. */
> dinfo->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
> @@ -1526,7 +1581,7 @@ static void split_bio_end(struct bio *bio, int error)
>
> static int blkif_recover(struct blkfront_dev_info *dinfo)
> {
> - int i;
> + int i, r_index;
> struct request *req, *n;
> struct blk_shadow *copy;
> int rc;
> @@ -1536,56 +1591,62 @@ static int blkif_recover(struct blkfront_dev_info *dinfo)
> int pending, size;
> struct split_bio *split_bio;
> struct list_head requests;
> - struct blkfront_ring_info *rinfo = &dinfo->rinfo;
> -
> - /* 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(dinfo); i++)
> - rinfo->shadow[i].req.u.rw.id = i+1;
> - rinfo->shadow_free = rinfo->ring.req_prod_pvt;
> - rinfo->shadow[BLK_RING_SIZE(dinfo)-1].req.u.rw.id = 0x0fffffff;
> -
> - rc = blkfront_gather_backend_features(dinfo);
> - if (rc) {
> - kfree(copy);
> - return rc;
> - }
> + struct blkfront_ring_info *rinfo;
>
> + __blkfront_gather_backend_features(dinfo);
> segs = dinfo->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
> blk_queue_max_segments(dinfo->rq, segs);
> bio_list_init(&bio_list);
> INIT_LIST_HEAD(&requests);
> - for (i = 0; i < BLK_RING_SIZE(dinfo); i++) {
> - /* Not in use? */
> - if (!copy[i].request)
> - continue;
>
> - /*
> - * Get the bios in the request so we can re-queue them.
> - */
> - if (copy[i].request->cmd_flags &
> - (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
> +
> + /* Stage 1: Make a safe copy of the shadow state. */
> + copy = kmemdup(rinfo->shadow, sizeof(rinfo->shadow),
> + GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
> + if (!copy)
> + return -ENOMEM;
> +
> + /* Stage 2: Set up free list. */
> + memset(&rinfo->shadow, 0, sizeof(rinfo->shadow));
> + for (i = 0; i < BLK_RING_SIZE(dinfo); i++)
> + rinfo->shadow[i].req.u.rw.id = i+1;
> + rinfo->shadow_free = rinfo->ring.req_prod_pvt;
> + rinfo->shadow[BLK_RING_SIZE(dinfo)-1].req.u.rw.id = 0x0fffffff;
> +
> + rc = blkfront_setup_indirect(rinfo);
> + if (rc) {
> + kfree(copy);
> + return rc;
> + }
> +
> + for (i = 0; i < BLK_RING_SIZE(dinfo); i++) {
> + /* Not in use? */
> + if (!copy[i].request)
> + continue;
> +
> /*
> - * Flush operations don't contain bios, so
> - * we need to requeue the whole request
> + * Get the bios in the request so we can re-queue them.
> */
> - list_add(©[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_end_request_all(copy[i].request, 0);
> }
> - merge_bio.head = copy[i].request->bio;
> - merge_bio.tail = copy[i].request->biotail;
> - bio_list_merge(&bio_list, &merge_bio);
> - copy[i].request->bio = NULL;
> - blk_end_request_all(copy[i].request, 0);
> - }
>
> - kfree(copy);
> + kfree(copy);
> + }
>
> xenbus_switch_state(dinfo->xbdev, XenbusStateConnected);
>
> @@ -1594,8 +1655,12 @@ static int blkif_recover(struct blkfront_dev_info *dinfo)
> /* Now safe for us to use the shared ring */
> dinfo->connected = BLKIF_STATE_CONNECTED;
>
> - /* Kick any other new requests queued since we resumed */
> - kick_pending_request_queues(rinfo);
> + for (r_index = 0; r_index < dinfo->nr_rings; r_index++) {
> + rinfo = &dinfo->rinfo[r_index];
> +
> + /* Kick any other new requests queued since we resumed */
> + kick_pending_request_queues(rinfo);
> + }
>
> list_for_each_entry_safe(req, n, &requests, queuelist) {
> /* Requeue pending requests (flush or discard) */
> @@ -1729,6 +1794,38 @@ static void blkfront_setup_discard(struct blkfront_dev_info *dinfo)
> dinfo->feature_secdiscard = !!discard_secure;
> }
>
> +static void blkfront_clean_ring(struct blkfront_ring_info *rinfo)
> +{
> + int i;
> +
> + for (i = 0; i < BLK_RING_SIZE(rinfo->dinfo); i++) {
> + 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, &rinfo->indirect_pages, lru) {
> + list_del(&indirect_page->lru);
> + __free_page(indirect_page);
> + }
> + }
> +
> + if (!list_empty(&rinfo->grants)) {
> + struct grant *gnt_list_entry, *n;
> + list_for_each_entry_safe(gnt_list_entry, n,
> + &rinfo->grants, node) {
> + list_del(&gnt_list_entry->node);
> + if (rinfo->dinfo->feature_persistent)
> + __free_page(pfn_to_page(gnt_list_entry->pfn));
> + kfree(gnt_list_entry);
> + }
> + }
> +}
> +
> static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
> {
> unsigned int segs;
> @@ -1783,28 +1880,14 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
> return 0;
>
> out_of_memory:
> - for (i = 0; i < BLK_RING_SIZE(dinfo); i++) {
> - 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, &rinfo->indirect_pages, lru) {
> - list_del(&indirect_page->lru);
> - __free_page(indirect_page);
> - }
> - }
> + blkfront_clean_ring(rinfo);
> return -ENOMEM;
> }
>
> /*
> * Gather all backend feature-*
> */
> -static int blkfront_gather_backend_features(struct blkfront_dev_info *dinfo)
> +static void __blkfront_gather_backend_features(struct blkfront_dev_info *dinfo)
> {
> int err;
> int barrier, flush, discard, persistent;
> @@ -1859,8 +1942,25 @@ static int blkfront_gather_backend_features(struct blkfront_dev_info *dinfo)
> else
> dinfo->max_indirect_segments = min(indirect_segments,
> xen_blkif_max_segments);
> +}
> +
> +static int blkfront_gather_backend_features(struct blkfront_dev_info *dinfo)
> +{
> + int err, i;
> +
> + __blkfront_gather_backend_features(dinfo);
IMHO, there's no need to introduce __blkfront_gather_backend_features,
just add the chunk below to the existing blkfront_gather_backend_features.
> - return blkfront_setup_indirect(&dinfo->rinfo);
> + for (i = 0; i < dinfo->nr_rings; i++) {
> + err = blkfront_setup_indirect(&dinfo->rinfo[i]);
> + if (err)
> + goto out;
> + }
> + return 0;
> +
> +out:
> + while (--i >= 0)
> + blkfront_clean_ring(&dinfo->rinfo[i]);
> + return err;
> }
>
> /*
> @@ -1873,8 +1973,8 @@ static void blkfront_connect(struct blkfront_dev_info *dinfo)
> unsigned long sector_size;
> unsigned int physical_sector_size;
> unsigned int binfo;
> - int err;
> - struct blkfront_ring_info *rinfo = &dinfo->rinfo;
> + int err, i;
> + struct blkfront_ring_info *rinfo;
>
> switch (dinfo->connected) {
> case BLKIF_STATE_CONNECTED:
> @@ -1951,7 +2051,10 @@ static void blkfront_connect(struct blkfront_dev_info *dinfo)
> /* Kick pending requests. */
> spin_lock_irq(&dinfo->io_lock);
> dinfo->connected = BLKIF_STATE_CONNECTED;
> - kick_pending_request_queues(rinfo);
> + for (i = 0; i < dinfo->nr_rings; i++) {
> + rinfo = &dinfo->rinfo[i];
If rinfo is only going to be used in the for loop you can declare it inside:
struct blkfront_ring_info *rinfo = &dinfo->rinfo[i];
> + kick_pending_request_queues(rinfo);
> + }
> spin_unlock_irq(&dinfo->io_lock);
>
> add_disk(dinfo->gd);
>
--
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