#include <linux/interrupt.h>
#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/hdreg.h>
#include <linux/cdrom.h>
#include <linux/module.h>
struct grant {
grant_ref_t gref;
- unsigned long pfn;
+ struct page *page;
struct list_head node;
};
struct grant **grants_used;
struct grant **indirect_grants;
struct scatterlist *sg;
+ unsigned int num_sg;
};
struct split_bio {
struct bio *bio;
atomic_t pending;
- int err;
};
static DEFINE_MUTEX(blkfront_mutex);
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, XEN_PAGE_SIZE * (info)->nr_ring_pages)
+
+#define BLK_MAX_RING_SIZE \
+ __CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * XENBUS_MAX_RING_GRANTS)
+
+/*
+ * 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
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int ring_ref;
+ 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_RING_SIZE];
+ struct blk_shadow shadow[BLK_MAX_RING_SIZE];
struct list_head grants;
struct list_head indirect_pages;
unsigned int persistent_gnts_c;
unsigned int discard_granularity;
unsigned int discard_alignment;
unsigned int feature_persistent:1;
+ /* Number of 4KB segments handled */
unsigned int max_indirect_segments;
int is_ready;
+ struct blk_mq_tag_set tag_set;
};
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
#define DEV_NAME "xvd" /* name in /dev */
-#define SEGS_PER_INDIRECT_FRAME \
- (PAGE_SIZE/sizeof(struct blkif_request_segment))
-#define INDIRECT_GREFS(_segs) \
- ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
+/*
+ * Grants are always the same size as a Xen page (i.e 4KB).
+ * A physical segment is always the same size as a Linux page.
+ * Number of grants per physical segment
+ */
+#define GRANTS_PER_PSEG (PAGE_SIZE / XEN_PAGE_SIZE)
+
+#define GRANTS_PER_INDIRECT_FRAME \
+ (XEN_PAGE_SIZE / sizeof(struct blkif_request_segment))
+
+#define PSEGS_PER_INDIRECT_FRAME \
+ (GRANTS_INDIRECT_FRAME / GRANTS_PSEGS)
+
+#define INDIRECT_GREFS(_grants) \
+ DIV_ROUND_UP(_grants, GRANTS_PER_INDIRECT_FRAME)
+
+#define GREFS(_psegs) ((_psegs) * GRANTS_PER_PSEG)
static int blkfront_setup_indirect(struct blkfront_info *info);
+static int blkfront_gather_backend_features(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;
kfree(gnt_list_entry);
goto out_of_memory;
}
- gnt_list_entry->pfn = page_to_pfn(granted_page);
+ gnt_list_entry->page = granted_page;
}
gnt_list_entry->gref = GRANT_INVALID_REF;
&info->grants, node) {
list_del(&gnt_list_entry->node);
if (info->feature_persistent)
- __free_page(pfn_to_page(gnt_list_entry->pfn));
+ __free_page(gnt_list_entry->page);
kfree(gnt_list_entry);
i--;
}
return -ENOMEM;
}
-static struct grant *get_grant(grant_ref_t *gref_head,
- unsigned long pfn,
- struct blkfront_info *info)
+static struct grant *get_free_grant(struct blkfront_info *info)
{
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,
- node);
+ node);
list_del(&gnt_list_entry->node);
- if (gnt_list_entry->gref != GRANT_INVALID_REF) {
+ if (gnt_list_entry->gref != GRANT_INVALID_REF)
info->persistent_gnts_c--;
+
+ return gnt_list_entry;
+}
+
+static inline void grant_foreign_access(const struct grant *gnt_list_entry,
+ const struct blkfront_info *info)
+{
+ gnttab_page_grant_foreign_access_ref_one(gnt_list_entry->gref,
+ info->xbdev->otherend_id,
+ gnt_list_entry->page,
+ 0);
+}
+
+static struct grant *get_grant(grant_ref_t *gref_head,
+ unsigned long gfn,
+ struct blkfront_info *info)
+{
+ struct grant *gnt_list_entry = get_free_grant(info);
+
+ if (gnt_list_entry->gref != GRANT_INVALID_REF)
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)
+ grant_foreign_access(gnt_list_entry, info);
+ else {
+ /* Grant access to the GFN passed by the caller */
+ gnttab_grant_foreign_access_ref(gnt_list_entry->gref,
+ info->xbdev->otherend_id,
+ gfn, 0);
}
+ return gnt_list_entry;
+}
+
+static struct grant *get_indirect_grant(grant_ref_t *gref_head,
+ struct blkfront_info *info)
+{
+ struct grant *gnt_list_entry = get_free_grant(info);
+
+ if (gnt_list_entry->gref != GRANT_INVALID_REF)
+ 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) {
- BUG_ON(!pfn);
- gnt_list_entry->pfn = pfn;
+ 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,
+ struct page, lru);
+ list_del(&indirect_page->lru);
+ gnt_list_entry->page = indirect_page;
}
- 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);
+ grant_foreign_access(gnt_list_entry, info);
+
return gnt_list_entry;
}
return 0;
}
-/*
- * Generate a Xen blkfront IO request from a blk layer request. Reads
- * and writes are handled as expected.
- *
- * @req: a request struct
- */
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_discard_req(struct request *req)
{
struct blkfront_info *info = req->rq_disk->private_data;
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->operation = BLKIF_OP_DISCARD;
+ ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
+ ring_req->u.discard.id = id;
+ ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req);
+ if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard)
+ ring_req->u.discard.flag = BLKIF_DISCARD_SECURE;
+ else
+ ring_req->u.discard.flag = 0;
+
+ info->ring.req_prod_pvt++;
+
+ /* Keep a private copy so we can reissue requests when recovering. */
+ info->shadow[id].req = *ring_req;
+
+ return 0;
+}
+
+struct setup_rw_req {
+ unsigned int grant_idx;
+ struct blkif_request_segment *segments;
+ struct blkfront_info *info;
+ struct blkif_request *ring_req;
+ grant_ref_t gref_head;
+ unsigned int id;
+ /* Only used when persistent grant is used and it's a read request */
+ bool need_copy;
+ unsigned int bvec_off;
+ char *bvec_data;
+};
+
+static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
+ unsigned int len, void *data)
+{
+ struct setup_rw_req *setup = data;
+ int n, ref;
+ struct grant *gnt_list_entry;
unsigned int fsect, lsect;
- int i, ref, n;
- struct blkif_request_segment *segments = NULL;
+ /* 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];
+
+ if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
+ (grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) {
+ if (setup->segments)
+ kunmap_atomic(setup->segments);
+
+ n = grant_idx / GRANTS_PER_INDIRECT_FRAME;
+ gnt_list_entry = get_indirect_grant(&setup->gref_head, info);
+ shadow->indirect_grants[n] = gnt_list_entry;
+ setup->segments = kmap_atomic(gnt_list_entry->page);
+ ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref;
+ }
+
+ gnt_list_entry = get_grant(&setup->gref_head, gfn, info);
+ ref = gnt_list_entry->gref;
+ shadow->grants_used[grant_idx] = gnt_list_entry;
+
+ if (setup->need_copy) {
+ void *shared_data;
+
+ shared_data = kmap_atomic(gnt_list_entry->page);
+ /*
+ * this does not wipe data stored outside the
+ * range sg->offset..sg->offset+sg->length.
+ * Therefore, blkback *could* see data from
+ * previous requests. This is OK as long as
+ * persistent grants are shared with just one
+ * domain. It may need refactoring if this
+ * changes
+ */
+ memcpy(shared_data + offset,
+ setup->bvec_data + setup->bvec_off,
+ len);
+
+ kunmap_atomic(shared_data);
+ setup->bvec_off += len;
+ }
+
+ fsect = offset >> 9;
+ lsect = fsect + (len >> 9) - 1;
+ if (ring_req->operation != BLKIF_OP_INDIRECT) {
+ ring_req->u.rw.seg[grant_idx] =
+ (struct blkif_request_segment) {
+ .gref = ref,
+ .first_sect = fsect,
+ .last_sect = lsect };
+ } else {
+ setup->segments[grant_idx % GRANTS_PER_INDIRECT_FRAME] =
+ (struct blkif_request_segment) {
+ .gref = ref,
+ .first_sect = fsect,
+ .last_sect = lsect };
+ }
+
+ (setup->grant_idx)++;
+}
+
+static int blkif_queue_rw_req(struct request *req)
+{
+ struct blkfront_info *info = req->rq_disk->private_data;
+ struct blkif_request *ring_req;
+ unsigned long id;
+ int i;
+ struct setup_rw_req setup = {
+ .grant_idx = 0,
+ .segments = NULL,
+ .info = info,
+ .need_copy = rq_data_dir(req) && info->feature_persistent,
+ };
/*
* Used to store if we are able to queue the request by just using
* as there are not sufficiently many free.
*/
bool new_persistent_gnts;
- grant_ref_t gref_head;
- struct grant *gnt_list_entry = NULL;
struct scatterlist *sg;
- int nseg, max_grefs;
-
- if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
- return 1;
+ int num_sg, max_grefs, num_grant;
- max_grefs = req->nr_phys_segments;
+ max_grefs = req->nr_phys_segments * GRANTS_PER_PSEG;
if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST)
/*
* If we are using indirect segments we need to account
* for the indirect grefs used in the request.
*/
- max_grefs += INDIRECT_GREFS(req->nr_phys_segments);
+ max_grefs += INDIRECT_GREFS(max_grefs);
/* Check if we have enough grants to allocate a requests */
if (info->persistent_gnts_c < max_grefs) {
new_persistent_gnts = 1;
if (gnttab_alloc_grant_references(
max_grefs - info->persistent_gnts_c,
- &gref_head) < 0) {
+ &setup.gref_head) < 0) {
gnttab_request_free_callback(
&info->callback,
blkif_restart_queue_callback,
id = get_id_from_freelist(info);
info->shadow[id].request = req;
- if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) {
- ring_req->operation = BLKIF_OP_DISCARD;
- ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
- ring_req->u.discard.id = id;
- ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req);
- if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard)
- ring_req->u.discard.flag = BLKIF_DISCARD_SECURE;
- else
- ring_req->u.discard.flag = 0;
+ 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_grant = 0;
+ /* Calculate the number of grant used */
+ for_each_sg(info->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;
+ if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
+ /*
+ * The indirect operation can only be a BLKIF_OP_READ or
+ * BLKIF_OP_WRITE
+ */
+ BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA));
+ ring_req->operation = BLKIF_OP_INDIRECT;
+ ring_req->u.indirect.indirect_op = rq_data_dir(req) ?
+ BLKIF_OP_WRITE : BLKIF_OP_READ;
+ ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req);
+ ring_req->u.indirect.handle = info->handle;
+ ring_req->u.indirect.nr_segments = num_grant;
} else {
- BUG_ON(info->max_indirect_segments == 0 &&
- 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);
- ring_req->u.rw.id = id;
- if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
+ ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req);
+ ring_req->u.rw.handle = info->handle;
+ ring_req->operation = rq_data_dir(req) ?
+ BLKIF_OP_WRITE : BLKIF_OP_READ;
+ if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
/*
- * The indirect operation can only be a BLKIF_OP_READ or
- * BLKIF_OP_WRITE
+ * Ideally we can do an unordered flush-to-disk.
+ * In case the backend onlysupports barriers, use that.
+ * A barrier request a superset of FUA, so we can
+ * implement it the same way. (It's also a FLUSH+FUA,
+ * since it is guaranteed ordered WRT previous writes.)
*/
- BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA));
- ring_req->operation = BLKIF_OP_INDIRECT;
- ring_req->u.indirect.indirect_op = rq_data_dir(req) ?
- BLKIF_OP_WRITE : BLKIF_OP_READ;
- ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req);
- ring_req->u.indirect.handle = info->handle;
- ring_req->u.indirect.nr_segments = nseg;
- } else {
- ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req);
- ring_req->u.rw.handle = info->handle;
- ring_req->operation = rq_data_dir(req) ?
- BLKIF_OP_WRITE : BLKIF_OP_READ;
- if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
- /*
- * Ideally we can do an unordered flush-to-disk. In case the
- * backend onlysupports barriers, use that. A barrier request
- * a superset of FUA, so we can implement it the same
- * way. (It's also a FLUSH+FUA, since it is
- * guaranteed ordered WRT previous writes.)
- */
- switch (info->feature_flush &
- ((REQ_FLUSH|REQ_FUA))) {
- case REQ_FLUSH|REQ_FUA:
- ring_req->operation =
- BLKIF_OP_WRITE_BARRIER;
- break;
- case REQ_FLUSH:
- ring_req->operation =
- BLKIF_OP_FLUSH_DISKCACHE;
- break;
- default:
- ring_req->operation = 0;
- }
+ switch (info->feature_flush &
+ ((REQ_FLUSH|REQ_FUA))) {
+ case REQ_FLUSH|REQ_FUA:
+ ring_req->operation =
+ BLKIF_OP_WRITE_BARRIER;
+ break;
+ case REQ_FLUSH:
+ ring_req->operation =
+ BLKIF_OP_FLUSH_DISKCACHE;
+ break;
+ default:
+ ring_req->operation = 0;
}
- ring_req->u.rw.nr_segments = nseg;
}
- for_each_sg(info->shadow[id].sg, sg, nseg, i) {
- fsect = sg->offset >> 9;
- lsect = fsect + (sg->length >> 9) - 1;
-
- if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
- (i % SEGS_PER_INDIRECT_FRAME == 0)) {
- unsigned long uninitialized_var(pfn);
-
- if (segments)
- kunmap_atomic(segments);
-
- n = i / SEGS_PER_INDIRECT_FRAME;
- if (!info->feature_persistent) {
- 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,
- 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;
- 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);
- ref = gnt_list_entry->gref;
-
- info->shadow[id].grants_used[i] = gnt_list_entry;
-
- if (rq_data_dir(req) && info->feature_persistent) {
- char *bvec_data;
- void *shared_data;
+ ring_req->u.rw.nr_segments = num_grant;
+ }
- BUG_ON(sg->offset + sg->length > PAGE_SIZE);
+ setup.ring_req = ring_req;
+ setup.id = id;
+ for_each_sg(info->shadow[id].sg, sg, num_sg, i) {
+ BUG_ON(sg->offset + sg->length > PAGE_SIZE);
- shared_data = kmap_atomic(pfn_to_page(gnt_list_entry->pfn));
- bvec_data = kmap_atomic(sg_page(sg));
+ if (setup.need_copy) {
+ setup.bvec_off = sg->offset;
+ setup.bvec_data = kmap_atomic(sg_page(sg));
+ }
- /*
- * this does not wipe data stored outside the
- * range sg->offset..sg->offset+sg->length.
- * Therefore, blkback *could* see data from
- * previous requests. This is OK as long as
- * persistent grants are shared with just one
- * domain. It may need refactoring if this
- * changes
- */
- memcpy(shared_data + sg->offset,
- bvec_data + sg->offset,
- sg->length);
+ gnttab_foreach_grant_in_range(sg_page(sg),
+ sg->offset,
+ sg->length,
+ blkif_setup_rw_req_grant,
+ &setup);
- kunmap_atomic(bvec_data);
- kunmap_atomic(shared_data);
- }
- if (ring_req->operation != BLKIF_OP_INDIRECT) {
- ring_req->u.rw.seg[i] =
- (struct blkif_request_segment) {
- .gref = ref,
- .first_sect = fsect,
- .last_sect = lsect };
- } else {
- n = i % SEGS_PER_INDIRECT_FRAME;
- segments[n] =
- (struct blkif_request_segment) {
- .gref = ref,
- .first_sect = fsect,
- .last_sect = lsect };
- }
- }
- if (segments)
- kunmap_atomic(segments);
+ if (setup.need_copy)
+ kunmap_atomic(setup.bvec_data);
}
+ if (setup.segments)
+ kunmap_atomic(setup.segments);
info->ring.req_prod_pvt++;
info->shadow[id].req = *ring_req;
if (new_persistent_gnts)
- gnttab_free_grant_references(gref_head);
+ gnttab_free_grant_references(setup.gref_head);
return 0;
}
+/*
+ * Generate a Xen blkfront IO request from a blk layer request. Reads
+ * and writes are handled as expected.
+ *
+ * @req: a request struct
+ */
+static int blkif_queue_request(struct request *req)
+{
+ struct blkfront_info *info = req->rq_disk->private_data;
+
+ if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
+ return 1;
+
+ if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE)))
+ return blkif_queue_discard_req(req);
+ else
+ return blkif_queue_rw_req(req);
+}
static inline void flush_requests(struct blkfront_info *info)
{
!(info->feature_flush & REQ_FUA)));
}
-/*
- * do_blkif_request
- * read a block; request is in a request queue
- */
-static void do_blkif_request(struct request_queue *rq)
+static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *qd)
{
- struct blkfront_info *info = NULL;
- struct request *req;
- int queued;
-
- pr_debug("Entered do_blkif_request\n");
+ struct blkfront_info *info = qd->rq->rq_disk->private_data;
- queued = 0;
-
- while ((req = blk_peek_request(rq)) != NULL) {
- info = req->rq_disk->private_data;
-
- if (RING_FULL(&info->ring))
- goto wait;
+ blk_mq_start_request(qd->rq);
+ spin_lock_irq(&info->io_lock);
+ if (RING_FULL(&info->ring))
+ goto out_busy;
- blk_start_request(req);
+ if (blkif_request_flush_invalid(qd->rq, info))
+ goto out_err;
- if (blkif_request_flush_invalid(req, info)) {
- __blk_end_request_all(req, -EOPNOTSUPP);
- continue;
- }
+ if (blkif_queue_request(qd->rq))
+ goto out_busy;
- pr_debug("do_blk_req %p: cmd %p, sec %lx, "
- "(%u/%u) [%s]\n",
- req, req->cmd, (unsigned long)blk_rq_pos(req),
- blk_rq_cur_sectors(req), blk_rq_sectors(req),
- rq_data_dir(req) ? "write" : "read");
-
- if (blkif_queue_request(req)) {
- blk_requeue_request(rq, req);
-wait:
- /* Avoid pointless unplugs. */
- blk_stop_queue(rq);
- break;
- }
+ flush_requests(info);
+ spin_unlock_irq(&info->io_lock);
+ return BLK_MQ_RQ_QUEUE_OK;
- queued++;
- }
+out_err:
+ spin_unlock_irq(&info->io_lock);
+ return BLK_MQ_RQ_QUEUE_ERROR;
- if (queued != 0)
- flush_requests(info);
+out_busy:
+ spin_unlock_irq(&info->io_lock);
+ blk_mq_stop_hw_queue(hctx);
+ return BLK_MQ_RQ_QUEUE_BUSY;
}
+static struct blk_mq_ops blkfront_mq_ops = {
+ .queue_rq = blkif_queue_rq,
+ .map_queue = blk_mq_map_queue,
+};
+
static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
unsigned int physical_sector_size,
unsigned int segments)
struct request_queue *rq;
struct blkfront_info *info = gd->private_data;
- rq = blk_init_queue(do_blkif_request, &info->io_lock);
- if (rq == NULL)
+ memset(&info->tag_set, 0, sizeof(info->tag_set));
+ info->tag_set.ops = &blkfront_mq_ops;
+ info->tag_set.nr_hw_queues = 1;
+ info->tag_set.queue_depth = BLK_RING_SIZE(info);
+ info->tag_set.numa_node = NUMA_NO_NODE;
+ info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ info->tag_set.cmd_size = 0;
+ info->tag_set.driver_data = info;
+
+ if (blk_mq_alloc_tag_set(&info->tag_set))
+ return -1;
+ rq = blk_mq_init_queue(&info->tag_set);
+ if (IS_ERR(rq)) {
+ blk_mq_free_tag_set(&info->tag_set);
return -1;
+ }
queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
/* Hard sector size and max sectors impersonate the equiv. hardware. */
blk_queue_logical_block_size(rq, sector_size);
blk_queue_physical_block_size(rq, physical_sector_size);
- blk_queue_max_hw_sectors(rq, (segments * PAGE_SIZE) / 512);
+ blk_queue_max_hw_sectors(rq, (segments * XEN_PAGE_SIZE) / 512);
/* Each segment in a request is up to an aligned page in size. */
blk_queue_segment_boundary(rq, PAGE_SIZE - 1);
blk_queue_max_segment_size(rq, PAGE_SIZE);
/* Ensure a merged request will fit in a single I/O ring slot. */
- blk_queue_max_segments(rq, segments);
+ blk_queue_max_segments(rq, segments / GRANTS_PER_PSEG);
/* Make sure buffer addresses are sector-aligned. */
blk_queue_dma_alignment(rq, 511);
static void xlvbd_release_gendisk(struct blkfront_info *info)
{
unsigned int minor, nr_minors;
- unsigned long flags;
if (info->rq == NULL)
return;
- spin_lock_irqsave(&info->io_lock, flags);
-
/* No more blkif_request(). */
- blk_stop_queue(info->rq);
+ blk_mq_stop_hw_queues(info->rq);
/* No more gnttab callback work. */
gnttab_cancel_free_callback(&info->callback);
- spin_unlock_irqrestore(&info->io_lock, flags);
/* Flush gnttab callback work. Must be done with no locks held. */
flush_work(&info->work);
xlbd_release_minors(minor, nr_minors);
blk_cleanup_queue(info->rq);
+ blk_mq_free_tag_set(&info->tag_set);
info->rq = NULL;
put_disk(info->gd);
info->gd = NULL;
}
+/* Must be called with io_lock holded */
static void kick_pending_request_queues(struct blkfront_info *info)
{
- if (!RING_FULL(&info->ring)) {
- /* Re-enable calldowns. */
- blk_start_queue(info->rq);
- /* Kick things off immediately. */
- do_blkif_request(info->rq);
- }
+ if (!RING_FULL(&info->ring))
+ blk_mq_start_stopped_hw_queues(info->rq, true);
}
static void blkif_restart_queue(struct work_struct *work)
BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED;
/* No more blkif_request(). */
if (info->rq)
- blk_stop_queue(info->rq);
+ blk_mq_stop_hw_queues(info->rq);
/* Remove all persistent grants */
if (!list_empty(&info->grants)) {
info->persistent_gnts_c--;
}
if (info->feature_persistent)
- __free_page(pfn_to_page(persistent_gnt->pfn));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
}
}
}
- 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
persistent_gnt = info->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));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
for (j = 0; j < INDIRECT_GREFS(segs); j++) {
persistent_gnt = info->shadow[i].indirect_grants[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
- __free_page(pfn_to_page(persistent_gnt->pfn));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
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;
}
+struct copy_from_grant {
+ const struct blk_shadow *s;
+ unsigned int grant_idx;
+ unsigned int bvec_offset;
+ char *bvec_data;
+};
+
+static void blkif_copy_from_grant(unsigned long gfn, unsigned int offset,
+ unsigned int len, void *data)
+{
+ struct copy_from_grant *info = data;
+ char *shared_data;
+ /* Convenient aliases */
+ const struct blk_shadow *s = info->s;
+
+ shared_data = kmap_atomic(s->grants_used[info->grant_idx]->page);
+
+ memcpy(info->bvec_data + info->bvec_offset,
+ shared_data + offset, len);
+
+ info->bvec_offset += len;
+ info->grant_idx++;
+
+ kunmap_atomic(shared_data);
+}
+
static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
struct blkif_response *bret)
{
int i = 0;
struct scatterlist *sg;
- char *bvec_data;
- void *shared_data;
- int nseg;
+ int num_sg, num_grant;
+ struct copy_from_grant data = {
+ .s = s,
+ .grant_idx = 0,
+ };
- nseg = s->req.operation == BLKIF_OP_INDIRECT ?
+ num_grant = s->req.operation == BLKIF_OP_INDIRECT ?
s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments;
+ num_sg = s->num_sg;
if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
- /*
- * Copy the data received from the backend into the bvec.
- * Since bv_offset can be different than 0, and bv_len different
- * than PAGE_SIZE, we have to keep track of the current offset,
- * to be sure we are copying the data from the right shared page.
- */
- for_each_sg(s->sg, sg, nseg, i) {
+ for_each_sg(s->sg, sg, num_sg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
- shared_data = kmap_atomic(
- pfn_to_page(s->grants_used[i]->pfn));
- bvec_data = kmap_atomic(sg_page(sg));
- memcpy(bvec_data + sg->offset,
- shared_data + sg->offset,
- sg->length);
- kunmap_atomic(bvec_data);
- kunmap_atomic(shared_data);
+
+ data.bvec_offset = sg->offset;
+ data.bvec_data = kmap_atomic(sg_page(sg));
+
+ gnttab_foreach_grant_in_range(sg_page(sg),
+ sg->offset,
+ sg->length,
+ blkif_copy_from_grant,
+ &data);
+
+ kunmap_atomic(data.bvec_data);
}
}
/* Add the persistent grant into the list of free grants */
- for (i = 0; i < nseg; i++) {
+ for (i = 0; i < num_grant; i++) {
if (gnttab_query_foreign_access(s->grants_used[i]->gref)) {
/*
* If the grant is still mapped by the backend (the
}
}
if (s->req.operation == BLKIF_OP_INDIRECT) {
- for (i = 0; i < INDIRECT_GREFS(nseg); i++) {
+ for (i = 0; i < INDIRECT_GREFS(num_grant); i++) {
if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) {
if (!info->feature_persistent)
pr_alert_ratelimited("backed has not unmapped grant: %u\n",
* available pages for indirect grefs.
*/
if (!info->feature_persistent) {
- indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
+ indirect_page = s->indirect_grants[i]->page;
list_add(&indirect_page->lru, &info->indirect_pages);
}
s->indirect_grants[i]->gref = GRANT_INVALID_REF;
* 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
queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq);
}
- __blk_end_request_all(req, error);
+ blk_mq_complete_request(req, error);
break;
case BLKIF_OP_FLUSH_DISKCACHE:
case BLKIF_OP_WRITE_BARRIER:
dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
"request: %x\n", bret->status);
- __blk_end_request_all(req, error);
+ blk_mq_complete_request(req, error);
break;
default:
BUG();
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 * XEN_PAGE_SIZE;
+ grant_ref_t gref[XENBUS_MAX_RING_GRANTS];
- 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)
{
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);
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);
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;
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. */
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);
- err = talk_to_blkback(dev, info);
- if (err) {
- kfree(info);
- dev_set_drvdata(&dev->dev, NULL);
- return err;
- }
-
return 0;
}
-static void split_bio_end(struct bio *bio, int error)
+static void split_bio_end(struct bio *bio)
{
struct split_bio *split_bio = bio->bi_private;
- if (error)
- split_bio->err = error;
-
if (atomic_dec_and_test(&split_bio->pending)) {
split_bio->bio->bi_phys_segments = 0;
- bio_endio(split_bio->bio, split_bio->err);
+ split_bio->bio->bi_error = bio->bi_error;
+ bio_endio(split_bio->bio);
kfree(split_bio);
}
bio_put(bio);
/* 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);
+ rc = blkfront_gather_backend_features(info);
if (rc) {
kfree(copy);
return rc;
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;
kfree(copy);
- /*
- * Empty the queue, this is important because we might have
- * requests in the queue with more segments than what we
- * can handle now.
- */
- spin_lock_irq(&info->io_lock);
- while ((req = blk_fetch_request(info->rq)) != NULL) {
- if (req->cmd_flags &
- (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) {
- list_add(&req->queuelist, &requests);
- continue;
- }
- merge_bio.head = req->bio;
- merge_bio.tail = req->biotail;
- bio_list_merge(&bio_list, &merge_bio);
- req->bio = NULL;
- if (req->cmd_flags & (REQ_FLUSH | REQ_FUA))
- pr_alert("diskcache flush request found!\n");
- __blk_end_request_all(req, 0);
- }
- spin_unlock_irq(&info->io_lock);
-
xenbus_switch_state(info->xbdev, XenbusStateConnected);
spin_lock_irq(&info->io_lock);
/* Requeue pending requests (flush or discard) */
list_del_init(&req->queuelist);
BUG_ON(req->nr_phys_segments > segs);
- blk_requeue_request(info->rq, req);
+ blk_mq_requeue_request(req);
}
spin_unlock_irq(&info->io_lock);
+ blk_mq_kick_requeue_list(info->rq);
while ((bio = bio_list_pop(&bio_list)) != NULL) {
/* Traverse the list of pending bios and re-queue them */
atomic_set(&split_bio->pending, pending);
split_bio->bio = bio;
for (i = 0; i < pending; i++) {
- offset = (i * segs * PAGE_SIZE) >> 9;
- size = min((unsigned int)(segs * PAGE_SIZE) >> 9,
+ offset = (i * segs * XEN_PAGE_SIZE) >> 9;
+ size = min((unsigned int)(segs * XEN_PAGE_SIZE) >> 9,
(unsigned int)bio_sectors(bio) - offset);
cloned_bio = bio_clone(bio, GFP_NOIO);
BUG_ON(cloned_bio == NULL);
static int blkfront_setup_indirect(struct blkfront_info *info)
{
- unsigned int indirect_segments, segs;
+ unsigned int psegs, grants;
int err, i;
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-max-indirect-segments", "%u", &indirect_segments,
- NULL);
- if (err) {
- info->max_indirect_segments = 0;
- segs = BLKIF_MAX_SEGMENTS_PER_REQUEST;
- } else {
- info->max_indirect_segments = min(indirect_segments,
- xen_blkif_max_segments);
- segs = info->max_indirect_segments;
- }
+ if (info->max_indirect_segments == 0)
+ grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ else
+ grants = info->max_indirect_segments;
+ psegs = grants / GRANTS_PER_PSEG;
- err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
+ err = fill_grant_buffer(info,
+ (grants + INDIRECT_GREFS(grants)) * BLK_RING_SIZE(info));
if (err)
goto out_of_memory;
* 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(grants) * BLK_RING_SIZE(info);
BUG_ON(!list_empty(&info->indirect_pages));
for (i = 0; i < num; i++) {
}
}
- 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,
+ sizeof(info->shadow[i].grants_used[0]) * grants,
GFP_NOIO);
- info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO);
+ info->shadow[i].sg = kzalloc(sizeof(info->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]) *
- INDIRECT_GREFS(segs),
+ INDIRECT_GREFS(grants),
GFP_NOIO);
if ((info->shadow[i].grants_used == NULL) ||
(info->shadow[i].sg == NULL) ||
(info->max_indirect_segments &&
(info->shadow[i].indirect_grants == NULL)))
goto out_of_memory;
- sg_init_table(info->shadow[i].sg, segs);
+ sg_init_table(info->shadow[i].sg, psegs);
}
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);
return -ENOMEM;
}
+/*
+ * Gather all backend feature-*
+ */
+static int blkfront_gather_backend_features(struct blkfront_info *info)
+{
+ int err;
+ int barrier, flush, discard, persistent;
+ unsigned int indirect_segments;
+
+ info->feature_flush = 0;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-barrier", "%d", &barrier,
+ NULL);
+
+ /*
+ * If there's no "feature-barrier" defined, then it means
+ * we're dealing with a very old backend which writes
+ * synchronously; nothing to do.
+ *
+ * If there are barriers, then we use flush.
+ */
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH | REQ_FUA;
+ /*
+ * And if there is "feature-flush-cache" use that above
+ * barriers.
+ */
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-flush-cache", "%d", &flush,
+ NULL);
+
+ if (!err && flush)
+ info->feature_flush = REQ_FLUSH;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-discard", "%d", &discard,
+ NULL);
+
+ if (!err && discard)
+ blkfront_setup_discard(info);
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-persistent", "%u", &persistent,
+ NULL);
+ if (err)
+ info->feature_persistent = 0;
+ else
+ info->feature_persistent = persistent;
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-max-indirect-segments", "%u", &indirect_segments,
+ NULL);
+ if (err)
+ info->max_indirect_segments = 0;
+ else
+ info->max_indirect_segments = min(indirect_segments,
+ xen_blkif_max_segments);
+
+ return blkfront_setup_indirect(info);
+}
+
/*
* Invoked when the backend is finally 'ready' (and has told produced
* the details about the physical device - #sectors, size, etc).
unsigned int physical_sector_size;
unsigned int binfo;
int err;
- int barrier, flush, discard, persistent;
switch (info->connected) {
case BLKIF_STATE_CONNECTED:
if (err != 1)
physical_sector_size = sector_size;
- info->feature_flush = 0;
-
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-barrier", "%d", &barrier,
- NULL);
-
- /*
- * If there's no "feature-barrier" defined, then it means
- * we're dealing with a very old backend which writes
- * synchronously; nothing to do.
- *
- * If there are barriers, then we use flush.
- */
- if (!err && barrier)
- info->feature_flush = REQ_FLUSH | REQ_FUA;
- /*
- * And if there is "feature-flush-cache" use that above
- * barriers.
- */
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-flush-cache", "%d", &flush,
- NULL);
-
- if (!err && flush)
- info->feature_flush = REQ_FLUSH;
-
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-discard", "%d", &discard,
- NULL);
-
- if (!err && discard)
- blkfront_setup_discard(info);
-
- err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
- "feature-persistent", "%u", &persistent,
- NULL);
- if (err)
- info->feature_persistent = 0;
- else
- info->feature_persistent = persistent;
-
- err = blkfront_setup_indirect(info);
+ err = blkfront_gather_backend_features(info);
if (err) {
xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
info->xbdev->otherend);
dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state);
switch (backend_state) {
- case XenbusStateInitialising:
case XenbusStateInitWait:
+ if (dev->state != XenbusStateInitialising)
+ break;
+ if (talk_to_blkback(dev, info)) {
+ kfree(info);
+ dev_set_drvdata(&dev->dev, NULL);
+ break;
+ }
+ case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
break;
/* Missed the backend's Closing state -- fallthrough */
case XenbusStateClosing:
- blkfront_closing(info);
+ if (info)
+ blkfront_closing(info);
break;
}
}
if (!xen_domain())
return -ENODEV;
+ if (xen_blkif_max_ring_order > XENBUS_MAX_RING_GRANT_ORDER) {
+ pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
+ xen_blkif_max_ring_order, XENBUS_MAX_RING_GRANT_ORDER);
+ xen_blkif_max_ring_order = 0;
+ }
+
if (!xen_has_pv_disk_devices())
return -ENODEV;
Code Review / kvmfornfv.git / blobdiff