From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH 3/3] xen/block: add multi-page ring support Date: Tue, 9 Jun 2015 09:39:43 -0400 Message-ID: <20150609133938.GA15200__6203.36290817267$1433857336$gmane$org@x230> References: <1433310003-13089-1-git-send-email-bob.liu@oracle.com> <1433310003-13089-3-git-send-email-bob.liu@oracle.com> <5576A8C0.8000804@oracle.com> <9AAE0902D5BC7E449B7C8E4E778ABCD0259410F3@AMSPEX01CL01.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <9AAE0902D5BC7E449B7C8E4E778ABCD0259410F3@AMSPEX01CL01.citrite.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Paul Durrant Cc: "linux-kernel@vger.kernel.org" , "xen-devel@lists.xen.org" , Julien Grall , "justing@spectralogic.com" , David Vrabel , Roger Pau Monne List-Id: xen-devel@lists.xenproject.org On Tue, Jun 09, 2015 at 08:52:53AM +0000, Paul Durrant wrote: > > -----Original Message----- > > From: Bob Liu [mailto:bob.liu@oracle.com] > > Sent: 09 June 2015 09:50 > > To: Bob Liu > > Cc: xen-devel@lists.xen.org; David Vrabel; justing@spectralogic.com; > > konrad.wilk@oracle.com; Roger Pau Monne; Paul Durrant; Julien Grall; linux- > > kernel@vger.kernel.org > > Subject: Re: [PATCH 3/3] xen/block: add multi-page ring support > > > > > > On 06/03/2015 01:40 PM, Bob Liu wrote: > > > Extend xen/block to support multi-page ring, so that more requests can be > > > issued by using more than one pages as the request ring between blkfront > > > and backend. > > > As a result, the performance can get improved significantly. > > > > > > We got some impressive improvements on our highend iscsi storage cluster > > > backend. If using 64 pages as the ring, the IOPS increased about 15 times > > > for the throughput testing and above doubled for the latency testing. > > > > > > The reason was the limit on outstanding requests is 32 if use only one-page > > > ring, but in our case the iscsi lun was spread across about 100 physical > > > drives, 32 was really not enough to keep them busy. > > > > > > Changes in v2: > > > - Rebased to 4.0-rc6. > > > - Document on how multi-page ring feature working to linux io/blkif.h. > > > > > > Changes in v3: > > > - Remove changes to linux io/blkif.h and follow the protocol defined > > > in io/blkif.h of XEN tree. > > > - Rebased to 4.1-rc3 > > > > > > Changes in v4: > > > - Turn to use 'ring-page-order' and 'max-ring-page-order'. > > > - A few comments from Roger. > > > > > > Changes in v5: > > > - Clarify with 4k granularity to comment > > > - Address more comments from Roger > > > > > > Signed-off-by: Bob Liu > > > > Also tested the windows PV driver which also works fine when multi-page > > ring feature > > was enabled in Linux backend. > > http://www.xenproject.org/downloads/windows-pv-drivers.html > > > > Great! Thanks for verifying that :-) Woot! Bob, could you repost the blkif.h patch for the Xen tree pleas e and also mention the testing part in it please? I think this was the only big 'what if?!' question holding this up. Roger, I put them (patches) on devel/for-jens-4.2 on git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git I think these two patches: drivers: xen-blkback: delay pending_req allocation to connect_ring xen/block: add multi-page ring support are the only ones that haven't been Acked by you (or maybe they have and I missed the Ack?) > > Paul > > > Regards, > > -Bob > > > > > --- > > > drivers/block/xen-blkback/blkback.c | 13 ++++ > > > drivers/block/xen-blkback/common.h | 2 + > > > drivers/block/xen-blkback/xenbus.c | 89 +++++++++++++++++------ > > > drivers/block/xen-blkfront.c | 135 +++++++++++++++++++++++++---- > > ------ > > > 4 files changed, 180 insertions(+), 59 deletions(-) > > > > > > diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen- > > blkback/blkback.c > > > index 713fc9f..2126842 100644 > > > --- a/drivers/block/xen-blkback/blkback.c > > > +++ b/drivers/block/xen-blkback/blkback.c > > > @@ -84,6 +84,13 @@ MODULE_PARM_DESC(max_persistent_grants, > > > "Maximum number of grants to map persistently"); > > > > > > /* > > > + * Maximum order of pages to be used for the shared ring between front > > and > > > + * backend, 4KB page granularity is used. > > > + */ > > > +unsigned int xen_blkif_max_ring_order = > > XENBUS_MAX_RING_PAGE_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"); > > > +/* > > > * The LRU mechanism to clean the lists of persistent grants needs to > > > * be executed periodically. The time interval between consecutive > > executions > > > * of the purge mechanism is set in ms. > > > @@ -1438,6 +1445,12 @@ static int __init xen_blkif_init(void) > > > if (!xen_domain()) > > > return -ENODEV; > > > > > > + if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) > > { > > > + pr_info("Invalid max_ring_order (%d), will use default max: > > %d.\n", > > > + xen_blkif_max_ring_order, > > XENBUS_MAX_RING_PAGE_ORDER); > > > + xen_blkif_max_ring_order = > > XENBUS_MAX_RING_PAGE_ORDER; > > > + } > > > + > > > rc = xen_blkif_interface_init(); > > > if (rc) > > > goto failed_init; > > > diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen- > > blkback/common.h > > > index 043f13b..8ccc49d 100644 > > > --- a/drivers/block/xen-blkback/common.h > > > +++ b/drivers/block/xen-blkback/common.h > > > @@ -44,6 +44,7 @@ > > > #include > > > #include > > > > > > +extern unsigned int xen_blkif_max_ring_order; > > > /* > > > * This is the maximum number of segments that would be allowed in > > indirect > > > * requests. This value will also be passed to the frontend. > > > @@ -320,6 +321,7 @@ struct xen_blkif { > > > struct work_struct free_work; > > > /* Thread shutdown wait queue. */ > > > wait_queue_head_t shutdown_wq; > > > + unsigned int nr_ring_pages; > > > }; > > > > > > struct seg_buf { > > > diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen- > > blkback/xenbus.c > > > index c212d41..deb3f00 100644 > > > --- a/drivers/block/xen-blkback/xenbus.c > > > +++ b/drivers/block/xen-blkback/xenbus.c > > > @@ -25,6 +25,7 @@ > > > > > > /* Enlarge the array size in order to fully show blkback name. */ > > > #define BLKBACK_NAME_LEN (20) > > > +#define RINGREF_NAME_LEN (20) > > > > > > struct backend_info { > > > struct xenbus_device *dev; > > > @@ -156,8 +157,8 @@ static struct xen_blkif *xen_blkif_alloc(domid_t > > domid) > > > return blkif; > > > } > > > > > > -static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref, > > > - unsigned int evtchn) > > > +static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t *gref, > > > + unsigned int nr_grefs, unsigned int evtchn) > > > { > > > int err; > > > > > > @@ -165,7 +166,7 @@ static int xen_blkif_map(struct xen_blkif *blkif, > > grant_ref_t gref, > > > if (blkif->irq) > > > return 0; > > > > > > - err = xenbus_map_ring_valloc(blkif->be->dev, &gref, 1, > > > + err = xenbus_map_ring_valloc(blkif->be->dev, gref, nr_grefs, > > > &blkif->blk_ring); > > > if (err < 0) > > > return err; > > > @@ -175,21 +176,21 @@ static int xen_blkif_map(struct xen_blkif *blkif, > > grant_ref_t gref, > > > { > > > struct blkif_sring *sring; > > > sring = (struct blkif_sring *)blkif->blk_ring; > > > - BACK_RING_INIT(&blkif->blk_rings.native, sring, > > PAGE_SIZE); > > > + BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE > > * nr_grefs); > > > 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); > > > + BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, > > PAGE_SIZE * nr_grefs); > > > 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); > > > + BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, > > PAGE_SIZE * nr_grefs); > > > break; > > > } > > > default: > > > @@ -270,7 +271,7 @@ static void xen_blkif_free(struct xen_blkif *blkif) > > > i++; > > > } > > > > > > - WARN_ON(i != XEN_BLKIF_REQS_PER_PAGE); > > > + WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif- > > >nr_ring_pages)); > > > > > > kmem_cache_free(xen_blkif_cachep, blkif); > > > } > > > @@ -555,6 +556,11 @@ static int xen_blkbk_probe(struct xenbus_device > > *dev, > > > if (err) > > > goto fail; > > > > > > + err = xenbus_printf(XBT_NIL, dev->nodename, "max-ring-page- > > order", "%u", > > > + xen_blkif_max_ring_order); > > > + if (err) > > > + pr_warn("%s write out 'max-ring-page-order' failed\n", > > __func__); > > > + > > > err = xenbus_switch_state(dev, XenbusStateInitWait); > > > if (err) > > > goto fail; > > > @@ -818,8 +824,8 @@ again: > > > static int connect_ring(struct backend_info *be) > > > { > > > struct xenbus_device *dev = be->dev; > > > - unsigned long ring_ref; > > > - unsigned int evtchn; > > > + unsigned int ring_ref[XENBUS_MAX_RING_PAGES]; > > > + unsigned int evtchn, nr_grefs, ring_page_order; > > > unsigned int pers_grants; > > > char protocol[64] = ""; > > > struct pending_req *req, *n; > > > @@ -827,14 +833,57 @@ static int connect_ring(struct backend_info *be) > > > > > > pr_debug("%s %s\n", __func__, 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", > > > + err = xenbus_scanf(XBT_NIL, dev->otherend, "event-channel", > > "%u", > > > + &evtchn); > > > + if (err != 1) { > > > + err = -EINVAL; > > > + xenbus_dev_fatal(dev, err, "reading %s/event-channel", > > > dev->otherend); > > > return err; > > > } > > > + pr_info("event-channel %u\n", evtchn); > > > + > > > + err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-page-order", > > "%u", > > > + &ring_page_order); > > > + if (err != 1) { > > > + err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", > > > + "%u", &ring_ref[0]); > > > + if (err != 1) { > > > + err = -EINVAL; > > > + xenbus_dev_fatal(dev, err, "reading %s/ring-ref", > > > + dev->otherend); > > > + return err; > > > + } > > > + nr_grefs = 1; > > > + pr_info("%s:using single page: ring-ref %d\n", dev- > > >otherend, > > > + ring_ref[0]); > > > + } else { > > > + unsigned int i; > > > + > > > + if (ring_page_order > xen_blkif_max_ring_order) { > > > + err = -EINVAL; > > > + xenbus_dev_fatal(dev, err, "%s/request %d ring > > page order exceed max:%d", > > > + dev->otherend, ring_page_order, > > > + xen_blkif_max_ring_order); > > > + return err; > > > + } > > > + > > > + nr_grefs = 1 << ring_page_order; > > > + for (i = 0; i < nr_grefs; i++) { > > > + char ring_ref_name[RINGREF_NAME_LEN]; > > > + > > > + snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring- > > ref%u", i); > > > + err = xenbus_scanf(XBT_NIL, dev->otherend, > > ring_ref_name, > > > + "%u", &ring_ref[i]); > > > + if (err != 1) { > > > + err = -EINVAL; > > > + xenbus_dev_fatal(dev, err, "reading %s/%s", > > > + dev->otherend, > > ring_ref_name); > > > + return err; > > > + } > > > + pr_info("ring-ref%u: %u\n", i, ring_ref[i]); > > > + } > > > + } > > > > > > be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; > > > err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", > > > @@ -859,12 +908,13 @@ static int connect_ring(struct backend_info *be) > > > > > > be->blkif->vbd.feature_gnt_persistent = pers_grants; > > > be->blkif->vbd.overflow_max_grants = 0; > > > + be->blkif->nr_ring_pages = nr_grefs; > > > > > > - pr_info("ring-ref %ld, event-channel %d, protocol %d (%s) %s\n", > > > - ring_ref, evtchn, be->blkif->blk_protocol, protocol, > > > + pr_info("ring-pages:%d, event-channel %d, protocol %d (%s) %s\n", > > > + nr_grefs, evtchn, be->blkif->blk_protocol, protocol, > > > pers_grants ? "persistent grants" : ""); > > > > > > - for (i = 0; i < XEN_BLKIF_REQS_PER_PAGE; i++) { > > > + for (i = 0; i < nr_grefs * XEN_BLKIF_REQS_PER_PAGE; i++) { > > > req = kzalloc(sizeof(*req), GFP_KERNEL); > > > if (!req) > > > goto fail; > > > @@ -883,10 +933,9 @@ static int connect_ring(struct backend_info *be) > > > } > > > > > > /* Map the shared frame, irq etc. */ > > > - err = xen_blkif_map(be->blkif, ring_ref, evtchn); > > > + err = xen_blkif_map(be->blkif, ring_ref, nr_grefs, evtchn); > > > if (err) { > > > - xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u", > > > - ring_ref, evtchn); > > > + xenbus_dev_fatal(dev, err, "mapping ring-ref port %u", > > evtchn); > > > return err; > > > } > > > > > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > > > index 88e23fd..d3c1a95 100644 > > > --- a/drivers/block/xen-blkfront.c > > > +++ b/drivers/block/xen-blkfront.c > > > @@ -98,7 +98,21 @@ 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)"); > > > > > > -#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) > > > +/* > > > + * Maximum order of pages to be used for the shared ring between front > > and > > > + * backend, 4KB page granularity is used. > > > + */ > > > +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(info) __CONST_RING_SIZE(blkif, PAGE_SIZE * > > (info)->nr_ring_pages) > > > +#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 > > > + * characters are enough. Define to 20 to keep consist with backend. > > > + */ > > > +#define RINGREF_NAME_LEN (20) > > > > > > /* > > > * We have one of these per vbd, whether ide, scsi or 'other'. They > > > @@ -114,13 +128,14 @@ struct blkfront_info > > > int vdevice; > > > blkif_vdev_t handle; > > > enum blkif_state connected; > > > - int ring_ref; > > > + int ring_ref[XENBUS_MAX_RING_PAGES]; > > > + 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_RING_SIZE]; > > > + struct blk_shadow shadow[BLK_MAX_RING_SIZE]; > > > struct list_head grants; > > > struct list_head indirect_pages; > > > unsigned int persistent_gnts_c; > > > @@ -139,8 +154,6 @@ static unsigned int nr_minors; > > > static unsigned long *minors; > > > static DEFINE_SPINLOCK(minor_lock); > > > > > > -#define MAXIMUM_OUTSTANDING_BLOCK_REQS \ > > > - (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE) > > > #define GRANT_INVALID_REF 0 > > > > > > #define PARTS_PER_DISK 16 > > > @@ -170,7 +183,7 @@ static int blkfront_setup_indirect(struct > > blkfront_info *info); > > > static int get_id_from_freelist(struct blkfront_info *info) > > > { > > > unsigned long free = info->shadow_free; > > > - BUG_ON(free >= BLK_RING_SIZE); > > > + 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 */ > > > return free; > > > @@ -983,7 +996,7 @@ static void blkif_free(struct blkfront_info *info, int > > suspend) > > > } > > > } > > > > > > - for (i = 0; i < BLK_RING_SIZE; i++) { > > > + for (i = 0; i < BLK_RING_SIZE(info); i++) { > > > /* > > > * Clear persistent grants present in requests already > > > * on the shared ring > > > @@ -1033,12 +1046,15 @@ free_shadow: > > > 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; > > > + 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; > > > + } > > > } > > > + free_pages((unsigned long)info->ring.sring, get_order(info- > > >nr_ring_pages * PAGE_SIZE)); > > > + info->ring.sring = NULL; > > > + > > > if (info->irq) > > > unbind_from_irqhandler(info->irq, info); > > > info->evtchn = info->irq = 0; > > > @@ -1157,7 +1173,7 @@ static irqreturn_t blkif_interrupt(int irq, void > > *dev_id) > > > * never have given to it (we stamp it up to BLK_RING_SIZE - > > > * look in get_id_from_freelist. > > > */ > > > - if (id >= BLK_RING_SIZE) { > > > + if (id >= BLK_RING_SIZE(info)) { > > > WARN(1, "%s: response to %s has incorrect id > > (%ld)\n", > > > info->gd->disk_name, op_name(bret->operation), > > id); > > > /* We can't safely get the 'struct request' as > > > @@ -1245,26 +1261,30 @@ static int setup_blkring(struct xenbus_device > > *dev, > > > struct blkfront_info *info) > > > { > > > struct blkif_sring *sring; > > > - grant_ref_t gref; > > > - int err; > > > + int err, i; > > > + unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE; > > > + grant_ref_t gref[XENBUS_MAX_RING_PAGES]; > > > > > > - info->ring_ref = GRANT_INVALID_REF; > > > + for (i = 0; i < info->nr_ring_pages; i++) > > > + info->ring_ref[i] = GRANT_INVALID_REF; > > > > > > - sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | > > __GFP_HIGH); > > > + sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | > > __GFP_HIGH, > > > + get_order(ring_size)); > > > if (!sring) { > > > xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); > > > return -ENOMEM; > > > } > > > SHARED_RING_INIT(sring); > > > - FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); > > > + FRONT_RING_INIT(&info->ring, sring, ring_size); > > > > > > - err = xenbus_grant_ring(dev, info->ring.sring, 1, &gref); > > > + err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, > > gref); > > > if (err < 0) { > > > - free_page((unsigned long)sring); > > > + free_pages((unsigned long)sring, get_order(ring_size)); > > > info->ring.sring = NULL; > > > goto fail; > > > } > > > - info->ring_ref = gref; > > > + for (i = 0; i < info->nr_ring_pages; i++) > > > + info->ring_ref[i] = gref[i]; > > > > > > err = xenbus_alloc_evtchn(dev, &info->evtchn); > > > if (err) > > > @@ -1292,7 +1312,18 @@ static int talk_to_blkback(struct xenbus_device > > *dev, > > > { > > > const char *message = NULL; > > > struct xenbus_transaction xbt; > > > - int err; > > > + int err, i; > > > + unsigned int max_page_order = 0; > > > + unsigned int ring_page_order = 0; > > > + > > > + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, > > > + "max-ring-page-order", "%u", &max_page_order); > > > + if (err != 1) > > > + info->nr_ring_pages = 1; > > > + else { > > > + ring_page_order = min(xen_blkif_max_ring_order, > > max_page_order); > > > + info->nr_ring_pages = 1 << ring_page_order; > > > + } > > > > > > /* Create shared ring, alloc event channel. */ > > > err = setup_blkring(dev, info); > > > @@ -1306,11 +1337,32 @@ 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; > > > + if (info->nr_ring_pages == 1) { > > > + err = xenbus_printf(xbt, dev->nodename, > > > + "ring-ref", "%u", info->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 < info->nr_ring_pages; i++) { > > > + char ring_ref_name[RINGREF_NAME_LEN]; > > > + > > > + snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring- > > ref%u", i); > > > + err = xenbus_printf(xbt, dev->nodename, > > ring_ref_name, > > > + "%u", info->ring_ref[i]); > > > + if (err) { > > > + message = "writing ring-ref"; > > > + goto abort_transaction; > > > + } > > > + } > > > } > > > err = xenbus_printf(xbt, dev->nodename, > > > "event-channel", "%u", info->evtchn); > > > @@ -1338,6 +1390,9 @@ again: > > > goto destroy_blkring; > > > } > > > > > > + for (i = 0; i < BLK_RING_SIZE(info); i++) > > > + info->shadow[i].req.u.rw.id = i+1; > > > + info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; > > > xenbus_switch_state(dev, XenbusStateInitialised); > > > > > > return 0; > > > @@ -1361,7 +1416,7 @@ again: > > > static int blkfront_probe(struct xenbus_device *dev, > > > const struct xenbus_device_id *id) > > > { > > > - int err, vdevice, i; > > > + int err, vdevice; > > > struct blkfront_info *info; > > > > > > /* FIXME: Use dynamic device id if this is not set. */ > > > @@ -1422,10 +1477,6 @@ static int blkfront_probe(struct xenbus_device > > *dev, > > > 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); > > > @@ -1469,10 +1520,10 @@ static int blkif_recover(struct blkfront_info > > *info) > > > > > > /* Stage 2: Set up free list. */ > > > memset(&info->shadow, 0, sizeof(info->shadow)); > > > - for (i = 0; i < BLK_RING_SIZE; i++) > > > + 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-1].req.u.rw.id = 0x0fffffff; > > > + info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; > > > > > > rc = blkfront_setup_indirect(info); > > > if (rc) { > > > @@ -1484,7 +1535,7 @@ static int blkif_recover(struct blkfront_info *info) > > > blk_queue_max_segments(info->rq, segs); > > > bio_list_init(&bio_list); > > > INIT_LIST_HEAD(&requests); > > > - for (i = 0; i < BLK_RING_SIZE; i++) { > > > + for (i = 0; i < BLK_RING_SIZE(info); i++) { > > > /* Not in use? */ > > > if (!copy[i].request) > > > continue; > > > @@ -1690,7 +1741,7 @@ 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(info, (segs + INDIRECT_GREFS(segs)) * > > BLK_RING_SIZE(info)); > > > if (err) > > > goto out_of_memory; > > > > > > @@ -1700,7 +1751,7 @@ static int blkfront_setup_indirect(struct > > blkfront_info *info) > > > * grants, we need to allocate a set of pages that can be > > > * used for mapping indirect grefs > > > */ > > > - int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE; > > > + int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info); > > > > > > BUG_ON(!list_empty(&info->indirect_pages)); > > > for (i = 0; i < num; i++) { > > > @@ -1711,7 +1762,7 @@ static int blkfront_setup_indirect(struct > > blkfront_info *info) > > > } > > > } > > > > > > - for (i = 0; i < BLK_RING_SIZE; i++) { > > > + for (i = 0; i < BLK_RING_SIZE(info); i++) { > > > info->shadow[i].grants_used = kzalloc( > > > sizeof(info->shadow[i].grants_used[0]) * segs, > > > GFP_NOIO); > > > @@ -1733,7 +1784,7 @@ static int blkfront_setup_indirect(struct > > blkfront_info *info) > > > return 0; > > > > > > out_of_memory: > > > - for (i = 0; i < BLK_RING_SIZE; i++) { > > > + 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); > > > @@ -2089,6 +2140,12 @@ static int __init xlblk_init(void) > > > if (!xen_domain()) > > > return -ENODEV; > > > > > > + if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) > > { > > > + pr_info("Invalid max_ring_order (%d), will use default max: > > %d.\n", > > > + xen_blkif_max_ring_order, > > XENBUS_MAX_RING_PAGE_ORDER); > > > + xen_blkif_max_ring_order = 0; > > > + } > > > + > > > if (!xen_has_pv_disk_devices()) > > > return -ENODEV; > > > > > >