MODULE_PARM_DESC(reqs, "Number of blkback requests to allocate");
/* Run-time switchable: /sys/module/blkback/parameters/ */
-static unsigned int log_stats = 0;
-static unsigned int debug_lvl = 0;
+static unsigned int log_stats;
+static unsigned int debug_lvl;
module_param(log_stats, int, 0644);
module_param(debug_lvl, int, 0644);
* the pendcnt towards zero. When it hits zero, the specified domain has a
* response queued for it, with the saved 'id' passed back.
*/
-typedef struct {
- blkif_t *blkif;
+struct pending_req {
+ struct blkif_st *blkif;
u64 id;
int nr_pages;
atomic_t pendcnt;
unsigned short operation;
int status;
struct list_head free_list;
-} pending_req_t;
+};
#define BLKBACK_INVALID_HANDLE (~0)
struct xen_blkbk {
- pending_req_t *pending_reqs;
+ struct pending_req *pending_reqs;
/* List of all 'pending_req' available */
struct list_head pending_free;
/* And its spinlock. */
* pending_pages[..]. For each 'pending_req' we have have up to
* BLKIF_MAX_SEGMENTS_PER_REQUEST (11) pages. The seg would be from 0 through
* 10 and would index in the pending_pages[..]. */
-static inline int vaddr_pagenr(pending_req_t *req, int seg)
+static inline int vaddr_pagenr(struct pending_req *req, int seg)
{
- return (req - blkbk->pending_reqs) * BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
+ return (req - blkbk->pending_reqs) *
+ BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
}
#define pending_page(req, seg) pending_pages[vaddr_pagenr(req, seg)]
-static inline unsigned long vaddr(pending_req_t *req, int seg)
+static inline unsigned long vaddr(struct pending_req *req, int seg)
{
unsigned long pfn = page_to_pfn(blkbk->pending_page(req, seg));
return (unsigned long)pfn_to_kaddr(pfn);
(blkbk->pending_grant_handles[vaddr_pagenr(_req, _seg)])
-static int do_block_io_op(blkif_t *blkif);
-static void dispatch_rw_block_io(blkif_t *blkif,
+static int do_block_io_op(struct blkif_st *blkif);
+static void dispatch_rw_block_io(struct blkif_st *blkif,
struct blkif_request *req,
- pending_req_t *pending_req);
-static void make_response(blkif_t *blkif, u64 id,
+ struct pending_req *pending_req);
+static void make_response(struct blkif_st *blkif, u64 id,
unsigned short op, int st);
/*
* Retrieve from the 'pending_reqs' a free pending_req structure to be used.
*/
-static pending_req_t* alloc_req(void)
+static struct pending_req *alloc_req(void)
{
- pending_req_t *req = NULL;
+ struct pending_req *req = NULL;
unsigned long flags;
spin_lock_irqsave(&blkbk->pending_free_lock, flags);
if (!list_empty(&blkbk->pending_free)) {
- req = list_entry(blkbk->pending_free.next, pending_req_t, free_list);
+ req = list_entry(blkbk->pending_free.next, struct pending_req,
+ free_list);
list_del(&req->free_list);
}
spin_unlock_irqrestore(&blkbk->pending_free_lock, flags);
* Return the 'pending_req' structure back to the freepool. We also
* wake up the thread if it was waiting for a free page.
*/
-static void free_req(pending_req_t *req)
+static void free_req(struct pending_req *req)
{
unsigned long flags;
int was_empty;
}
/*
- * Give back a reference count on the underlaying storage.
- * It is OK to make multiple calls in this function as it
- * resets the plug to NULL when it is done on the first call.
+ * Notification from the guest OS.
*/
-static void unplug_queue(blkif_t *blkif)
+static void blkif_notify_work(struct blkif_st *blkif)
{
- if (blkif->plug == NULL)
- return;
- if (blkif->plug->unplug_fn)
- blkif->plug->unplug_fn(blkif->plug);
- blk_put_queue(blkif->plug);
- blkif->plug = NULL;
+ blkif->waiting_reqs = 1;
+ wake_up(&blkif->wq);
}
-/*
- * Take a reference count on the underlaying storage.
- * It is OK to call this multiple times as we check to make sure
- * not to double reference. We also give back a reference count
- * if it corresponds to another queue.
- */
-static void plug_queue(blkif_t *blkif, struct block_device *bdev)
+irqreturn_t blkif_be_int(int irq, void *dev_id)
{
- struct request_queue *q = bdev_get_queue(bdev);
-
- if (q == blkif->plug)
- return;
- unplug_queue(blkif);
- blk_get_queue(q);
- blkif->plug = q;
+ blkif_notify_work(dev_id);
+ return IRQ_HANDLED;
}
/*
- * Unmap the grant references, and also remove the M2P over-rides
- * used in the 'pending_req'.
-*/
-static void fast_flush_area(pending_req_t *req)
-{
- struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
- unsigned int i, invcount = 0;
- grant_handle_t handle;
- int ret;
-
- for (i = 0; i < req->nr_pages; i++) {
- handle = pending_handle(req, i);
- if (handle == BLKBACK_INVALID_HANDLE)
- continue;
- gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
- GNTMAP_host_map, handle);
- pending_handle(req, i) = BLKBACK_INVALID_HANDLE;
- invcount++;
- }
-
- ret = HYPERVISOR_grant_table_op(
- GNTTABOP_unmap_grant_ref, unmap, invcount);
- BUG_ON(ret);
- /* Note, we use invcount, so nr->pages, so we can't index
- * using vaddr(req, i). */
- for (i = 0; i < invcount; i++) {
- ret = m2p_remove_override(
- virt_to_page(unmap[i].host_addr), false);
- if (ret) {
- printk(KERN_ALERT "Failed to remove M2P override for " \
- "%lx\n", (unsigned long)unmap[i].host_addr);
- continue;
- }
- }
-}
-
-/******************************************************************
* SCHEDULER FUNCTIONS
*/
-static void print_stats(blkif_t *blkif)
+static void print_stats(struct blkif_st *blkif)
{
printk(KERN_DEBUG "%s: oo %3d | rd %4d | wr %4d | br %4d\n",
current->comm, blkif->st_oo_req,
int blkif_schedule(void *arg)
{
- blkif_t *blkif = arg;
+ struct blkif_st *blkif = arg;
struct vbd *vbd = &blkif->vbd;
blkif_get(blkif);
blkif->waiting_reqs || kthread_should_stop());
wait_event_interruptible(
blkbk->pending_free_wq,
- !list_empty(&blkbk->pending_free) || kthread_should_stop());
+ !list_empty(&blkbk->pending_free) ||
+ kthread_should_stop());
blkif->waiting_reqs = 0;
smp_mb(); /* clear flag *before* checking for work */
if (do_block_io_op(blkif))
blkif->waiting_reqs = 1;
- unplug_queue(blkif);
if (log_stats && time_after(jiffies, blkif->st_print))
print_stats(blkif);
return 0;
}
+/*
+ * Unmap the grant references, and also remove the M2P over-rides
+ * used in the 'pending_req'.
+*/
+static void fast_flush_area(struct pending_req *req)
+{
+ struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+ unsigned int i, invcount = 0;
+ grant_handle_t handle;
+ int ret;
+
+ for (i = 0; i < req->nr_pages; i++) {
+ handle = pending_handle(req, i);
+ if (handle == BLKBACK_INVALID_HANDLE)
+ continue;
+ gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
+ GNTMAP_host_map, handle);
+ pending_handle(req, i) = BLKBACK_INVALID_HANDLE;
+ invcount++;
+ }
+
+ ret = HYPERVISOR_grant_table_op(
+ GNTTABOP_unmap_grant_ref, unmap, invcount);
+ BUG_ON(ret);
+ /* Note, we use invcount, so nr->pages, so we can't index
+ * using vaddr(req, i).
+ */
+ for (i = 0; i < invcount; i++) {
+ ret = m2p_remove_override(
+ virt_to_page(unmap[i].host_addr), false);
+ if (ret) {
+ printk(KERN_ALERT "Failed to remove M2P override for " \
+ "%lx\n", (unsigned long)unmap[i].host_addr);
+ continue;
+ }
+ }
+}
/*
* Completion callback on the bio's. Called as bh->b_end_io()
*/
-static void __end_block_io_op(pending_req_t *pending_req, int error)
+static void __end_block_io_op(struct pending_req *pending_req, int error)
{
/* An error fails the entire request. */
if ((pending_req->operation == BLKIF_OP_WRITE_BARRIER) &&
/* If all of the bio's have completed it is time to unmap
* the grant references associated with 'request' and provide
- * the proper response on the ring. */
+ * the proper response on the ring.
+ */
if (atomic_dec_and_test(&pending_req->pendcnt)) {
fast_flush_area(pending_req);
make_response(pending_req->blkif, pending_req->id,
}
-/*
- * Notification from the guest OS.
- */
-
-static void blkif_notify_work(blkif_t *blkif)
-{
- blkif->waiting_reqs = 1;
- wake_up(&blkif->wq);
-}
-
-irqreturn_t blkif_be_int(int irq, void *dev_id)
-{
- blkif_notify_work(dev_id);
- return IRQ_HANDLED;
-}
-
-
/*
* Function to copy the from the ring buffer the 'struct blkif_request'
* (which has the sectors we want, number of them, grant references, etc),
* and transmute it to the block API to hand it over to the proper block disk.
*/
-static int do_block_io_op(blkif_t *blkif)
+static int do_block_io_op(struct blkif_st *blkif)
{
union blkif_back_rings *blk_rings = &blkif->blk_rings;
struct blkif_request req;
- pending_req_t *pending_req;
+ struct pending_req *pending_req;
RING_IDX rc, rp;
int more_to_do = 0;
* Transumation of the 'struct blkif_request' to a proper 'struct bio'
* and call the 'submit_bio' to pass it to the underlaying storage.
*/
-static void dispatch_rw_block_io(blkif_t *blkif,
+static void dispatch_rw_block_io(struct blkif_st *blkif,
struct blkif_request *req,
- pending_req_t *pending_req)
+ struct pending_req *pending_req)
{
struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct phys_req preq;
} seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
unsigned int nseg;
struct bio *bio = NULL;
- int ret, i;
+ struct bio *biolist[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+ int ret, i, nbio = 0;
int operation;
+ struct blk_plug plug;
+ struct request_queue *q;
switch (req->operation) {
case BLKIF_OP_READ:
/* Fill out preq.nr_sects with proper amount of sectors, and setup
* assign map[..] with the PFN of the page in our domain with the
- * corresponding grant reference for each page.*/
+ * corresponding grant reference for each page.
+ */
for (i = 0; i < nseg; i++) {
uint32_t flags;
BUG_ON(ret);
/* Now swizzel the MFN in our domain with the MFN from the other domain
- * so that when we access vaddr(pending_req,i) it has the contents of the
- * page from the other domain. */
+ * so that when we access vaddr(pending_req,i) it has the contents of
+ * the page from the other domain.
+ */
for (i = 0; i < nseg; i++) {
if (unlikely(map[i].status != 0)) {
DPRINTK("invalid buffer -- could not remap it\n");
if (ret)
continue;
-
+
ret = m2p_add_override(PFN_DOWN(map[i].dev_bus_addr),
blkbk->pending_page(pending_req, i), false);
if (ret) {
printk(KERN_ALERT "Failed to install M2P override for"\
- " %lx (ret: %d)\n", (unsigned long)map[i].dev_bus_addr, ret);
+ " %lx (ret: %d)\n", (unsigned long)
+ map[i].dev_bus_addr, ret);
/* We could switch over to GNTTABOP_copy */
continue;
}
(req->u.rw.seg[i].first_sect << 9);
}
- /* If we have failed at this point, we need to undo the M2P override, set
- * gnttab_set_unmap_op on all of the grant references and perform the
- * hypercall to unmap the grants - that is all done in fast_flush_area. */
+ /* If we have failed at this point, we need to undo the M2P override,
+ * set gnttab_set_unmap_op on all of the grant references and perform
+ * the hypercall to unmap the grants - that is all done in
+ * fast_flush_area.
+ */
if (ret)
goto fail_flush;
goto fail_flush;
}
- /* Get a reference count for the disk queue and start sending I/O */
- plug_queue(blkif, preq.bdev);
-
- /* We set it one so that the last submit_bio does not have to call
- * atomic_inc. */
- atomic_set(&pending_req->pendcnt, 1);
+ /* This corresponding blkif_put is done in __end_block_io_op */
blkif_get(blkif);
for (i = 0; i < nseg; i++) {
blkbk->pending_page(pending_req, i),
seg[i].nsec << 9,
seg[i].buf & ~PAGE_MASK) == 0)) {
- if (bio) {
- atomic_inc(&pending_req->pendcnt);
- submit_bio(operation, bio);
- }
-
- bio = bio_alloc(GFP_KERNEL, nseg-i);
+
+ bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, nseg-i);
if (unlikely(bio == NULL))
goto fail_put_bio;
/* This will be hit if the operation was a barrier. */
if (!bio) {
BUG_ON(operation != WRITE_BARRIER);
- bio = bio_alloc(GFP_KERNEL, 0);
+ bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, 0);
if (unlikely(bio == NULL))
goto fail_put_bio;
bio->bi_sector = -1;
}
- submit_bio(operation, bio);
+
+ /* We set it one so that the last submit_bio does not have to call
+ * atomic_inc.
+ */
+ atomic_set(&pending_req->pendcnt, nbio);
+
+ /* Get a reference count for the disk queue and start sending I/O */
+ blk_get_queue(q);
+ blk_start_plug(&plug);
+
+ for (i = 0; i < nbio; i++)
+ submit_bio(operation, biolist[i]);
+
+ blk_finish_plug(&plug);
+ /* Let the I/Os go.. */
+ blk_put_queue(q);
if (operation == READ)
blkif->st_rd_sect += preq.nr_sects;
fail_flush:
fast_flush_area(pending_req);
fail_response:
+ /* Haven't submitted any bio's yet. */
make_response(blkif, req->id, req->operation, BLKIF_RSP_ERROR);
free_req(pending_req);
msleep(1); /* back off a bit */
return;
fail_put_bio:
+ for (i = 0; i < (nbio-1); i++)
+ bio_put(biolist[i]);
__end_block_io_op(pending_req, -EINVAL);
- if (bio)
- bio_put(bio);
- unplug_queue(blkif);
msleep(1); /* back off a bit */
return;
}
/*
* Put a response on the ring on how the operation fared.
*/
-static void make_response(blkif_t *blkif, u64 id,
+static void make_response(struct blkif_st *blkif, u64 id,
unsigned short op, int st)
{
struct blkif_response resp;
if (!xen_pv_domain())
return -ENODEV;
- blkbk = (struct xen_blkbk *)kzalloc(sizeof(struct xen_blkbk), GFP_KERNEL);
+ blkbk = kzalloc(sizeof(struct xen_blkbk), GFP_KERNEL);
if (!blkbk) {
printk(KERN_ALERT "%s: out of memory!\n", __func__);
return -ENOMEM;
blkbk->pending_pages = kzalloc(sizeof(blkbk->pending_pages[0]) *
mmap_pages, GFP_KERNEL);
- if (!blkbk->pending_reqs || !blkbk->pending_grant_handles || !blkbk->pending_pages) {
+ if (!blkbk->pending_reqs || !blkbk->pending_grant_handles ||
+ !blkbk->pending_pages) {
rc = -ENOMEM;
goto out_of_memory;
}
init_waitqueue_head(&blkbk->pending_free_wq);
for (i = 0; i < blkif_reqs; i++)
- list_add_tail(&blkbk->pending_reqs[i].free_list, &blkbk->pending_free);
+ list_add_tail(&blkbk->pending_reqs[i].free_list,
+ &blkbk->pending_free);
rc = blkif_xenbus_init();
if (rc)
projects / firefly-linux-kernel-4.4.55.git / blobdiff