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-rw-r--r--drivers/block/null_blk.c97
-rw-r--r--drivers/block/virtio_blk.c7
-rw-r--r--drivers/block/xen-blkback/blkback.c66
-rw-r--r--drivers/block/xen-blkback/common.h5
-rw-r--r--drivers/block/xen-blkback/xenbus.c14
-rw-r--r--drivers/block/xen-blkfront.c11
6 files changed, 105 insertions, 95 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 3107282..091b9ea 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -60,7 +60,9 @@ enum {
NULL_IRQ_NONE = 0,
NULL_IRQ_SOFTIRQ = 1,
NULL_IRQ_TIMER = 2,
+};
+enum {
NULL_Q_BIO = 0,
NULL_Q_RQ = 1,
NULL_Q_MQ = 2,
@@ -172,18 +174,20 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait)
static void end_cmd(struct nullb_cmd *cmd)
{
- if (cmd->rq) {
- if (queue_mode == NULL_Q_MQ)
- blk_mq_end_io(cmd->rq, 0);
- else {
- INIT_LIST_HEAD(&cmd->rq->queuelist);
- blk_end_request_all(cmd->rq, 0);
- }
- } else if (cmd->bio)
+ switch (queue_mode) {
+ case NULL_Q_MQ:
+ blk_mq_end_io(cmd->rq, 0);
+ return;
+ case NULL_Q_RQ:
+ INIT_LIST_HEAD(&cmd->rq->queuelist);
+ blk_end_request_all(cmd->rq, 0);
+ break;
+ case NULL_Q_BIO:
bio_endio(cmd->bio, 0);
+ break;
+ }
- if (queue_mode != NULL_Q_MQ)
- free_cmd(cmd);
+ free_cmd(cmd);
}
static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
@@ -195,6 +199,7 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
cq = &per_cpu(completion_queues, smp_processor_id());
while ((entry = llist_del_all(&cq->list)) != NULL) {
+ entry = llist_reverse_order(entry);
do {
cmd = container_of(entry, struct nullb_cmd, ll_list);
end_cmd(cmd);
@@ -221,61 +226,31 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd)
static void null_softirq_done_fn(struct request *rq)
{
- blk_end_request_all(rq, 0);
-}
-
-#ifdef CONFIG_SMP
-
-static void null_ipi_cmd_end_io(void *data)
-{
- struct completion_queue *cq;
- struct llist_node *entry, *next;
- struct nullb_cmd *cmd;
-
- cq = &per_cpu(completion_queues, smp_processor_id());
-
- entry = llist_del_all(&cq->list);
-
- while (entry) {
- next = entry->next;
- cmd = llist_entry(entry, struct nullb_cmd, ll_list);
- end_cmd(cmd);
- entry = next;
- }
-}
-
-static void null_cmd_end_ipi(struct nullb_cmd *cmd)
-{
- struct call_single_data *data = &cmd->csd;
- int cpu = get_cpu();
- struct completion_queue *cq = &per_cpu(completion_queues, cpu);
-
- cmd->ll_list.next = NULL;
-
- if (llist_add(&cmd->ll_list, &cq->list)) {
- data->func = null_ipi_cmd_end_io;
- data->flags = 0;
- __smp_call_function_single(cpu, data, 0);
- }
-
- put_cpu();
+ end_cmd(rq->special);
}
-#endif /* CONFIG_SMP */
-
static inline void null_handle_cmd(struct nullb_cmd *cmd)
{
/* Complete IO by inline, softirq or timer */
switch (irqmode) {
- case NULL_IRQ_NONE:
- end_cmd(cmd);
- break;
case NULL_IRQ_SOFTIRQ:
-#ifdef CONFIG_SMP
- null_cmd_end_ipi(cmd);
-#else
+ switch (queue_mode) {
+ case NULL_Q_MQ:
+ blk_mq_complete_request(cmd->rq);
+ break;
+ case NULL_Q_RQ:
+ blk_complete_request(cmd->rq);
+ break;
+ case NULL_Q_BIO:
+ /*
+ * XXX: no proper submitting cpu information available.
+ */
+ end_cmd(cmd);
+ break;
+ }
+ break;
+ case NULL_IRQ_NONE:
end_cmd(cmd);
-#endif
break;
case NULL_IRQ_TIMER:
null_cmd_end_timer(cmd);
@@ -411,6 +386,7 @@ static struct blk_mq_ops null_mq_ops = {
.queue_rq = null_queue_rq,
.map_queue = blk_mq_map_queue,
.init_hctx = null_init_hctx,
+ .complete = null_softirq_done_fn,
};
static struct blk_mq_reg null_mq_reg = {
@@ -609,13 +585,6 @@ static int __init null_init(void)
{
unsigned int i;
-#if !defined(CONFIG_SMP)
- if (irqmode == NULL_IRQ_SOFTIRQ) {
- pr_warn("null_blk: softirq completions not available.\n");
- pr_warn("null_blk: using direct completions.\n");
- irqmode = NULL_IRQ_NONE;
- }
-#endif
if (bs > PAGE_SIZE) {
pr_warn("null_blk: invalid block size\n");
pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6a680d4..b1cb3f4 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -110,9 +110,9 @@ static int __virtblk_add_req(struct virtqueue *vq,
return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
}
-static inline void virtblk_request_done(struct virtblk_req *vbr)
+static inline void virtblk_request_done(struct request *req)
{
- struct request *req = vbr->req;
+ struct virtblk_req *vbr = req->special;
int error = virtblk_result(vbr);
if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
@@ -138,7 +138,7 @@ static void virtblk_done(struct virtqueue *vq)
do {
virtqueue_disable_cb(vq);
while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
- virtblk_request_done(vbr);
+ blk_mq_complete_request(vbr->req);
req_done = true;
}
if (unlikely(virtqueue_is_broken(vq)))
@@ -479,6 +479,7 @@ static struct blk_mq_ops virtio_mq_ops = {
.map_queue = blk_mq_map_queue,
.alloc_hctx = blk_mq_alloc_single_hw_queue,
.free_hctx = blk_mq_free_single_hw_queue,
+ .complete = virtblk_request_done,
};
static struct blk_mq_reg virtio_mq_reg = {
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 4b97b86..64c60ed 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -299,7 +299,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
BUG_ON(num != 0);
}
-static void unmap_purged_grants(struct work_struct *work)
+void xen_blkbk_unmap_purged_grants(struct work_struct *work)
{
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
@@ -375,7 +375,7 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
pr_debug(DRV_PFX "Going to purge %u persistent grants\n", num_clean);
- INIT_LIST_HEAD(&blkif->persistent_purge_list);
+ BUG_ON(!list_empty(&blkif->persistent_purge_list));
root = &blkif->persistent_gnts;
purge_list:
foreach_grant_safe(persistent_gnt, n, root, node) {
@@ -420,7 +420,6 @@ finished:
blkif->vbd.overflow_max_grants = 0;
/* We can defer this work */
- INIT_WORK(&blkif->persistent_purge_work, unmap_purged_grants);
schedule_work(&blkif->persistent_purge_work);
pr_debug(DRV_PFX "Purged %u/%u\n", (total - num_clean), total);
return;
@@ -625,9 +624,23 @@ purge_gnt_list:
print_stats(blkif);
}
- /* Since we are shutting down remove all pages from the buffer */
- shrink_free_pagepool(blkif, 0 /* All */);
+ /* Drain pending purge work */
+ flush_work(&blkif->persistent_purge_work);
+ if (log_stats)
+ print_stats(blkif);
+
+ blkif->xenblkd = NULL;
+ xen_blkif_put(blkif);
+
+ return 0;
+}
+
+/*
+ * Remove persistent grants and empty the pool of free pages
+ */
+void xen_blkbk_free_caches(struct xen_blkif *blkif)
+{
/* Free all persistent grant pages */
if (!RB_EMPTY_ROOT(&blkif->persistent_gnts))
free_persistent_gnts(blkif, &blkif->persistent_gnts,
@@ -636,13 +649,8 @@ purge_gnt_list:
BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));
blkif->persistent_gnt_c = 0;
- if (log_stats)
- print_stats(blkif);
-
- blkif->xenblkd = NULL;
- xen_blkif_put(blkif);
-
- return 0;
+ /* Since we are shutting down remove all pages from the buffer */
+ shrink_free_pagepool(blkif, 0 /* All */);
}
/*
@@ -838,7 +846,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
struct grant_page **pages = pending_req->indirect_pages;
struct xen_blkif *blkif = pending_req->blkif;
int indirect_grefs, rc, n, nseg, i;
- struct blkif_request_segment_aligned *segments = NULL;
+ struct blkif_request_segment *segments = NULL;
nseg = pending_req->nr_pages;
indirect_grefs = INDIRECT_PAGES(nseg);
@@ -934,9 +942,7 @@ static void xen_blk_drain_io(struct xen_blkif *blkif)
{
atomic_set(&blkif->drain, 1);
do {
- /* The initial value is one, and one refcnt taken at the
- * start of the xen_blkif_schedule thread. */
- if (atomic_read(&blkif->refcnt) <= 2)
+ if (atomic_read(&blkif->inflight) == 0)
break;
wait_for_completion_interruptible_timeout(
&blkif->drain_complete, HZ);
@@ -976,17 +982,30 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
* the proper response on the ring.
*/
if (atomic_dec_and_test(&pending_req->pendcnt)) {
- xen_blkbk_unmap(pending_req->blkif,
+ struct xen_blkif *blkif = pending_req->blkif;
+
+ xen_blkbk_unmap(blkif,
pending_req->segments,
pending_req->nr_pages);
- make_response(pending_req->blkif, pending_req->id,
+ make_response(blkif, pending_req->id,
pending_req->operation, pending_req->status);
- xen_blkif_put(pending_req->blkif);
- if (atomic_read(&pending_req->blkif->refcnt) <= 2) {
- if (atomic_read(&pending_req->blkif->drain))
- complete(&pending_req->blkif->drain_complete);
+ free_req(blkif, pending_req);
+ /*
+ * Make sure the request is freed before releasing blkif,
+ * or there could be a race between free_req and the
+ * cleanup done in xen_blkif_free during shutdown.
+ *
+ * NB: The fact that we might try to wake up pending_free_wq
+ * before drain_complete (in case there's a drain going on)
+ * it's not a problem with our current implementation
+ * because we can assure there's no thread waiting on
+ * pending_free_wq if there's a drain going on, but it has
+ * to be taken into account if the current model is changed.
+ */
+ if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) {
+ complete(&blkif->drain_complete);
}
- free_req(pending_req->blkif, pending_req);
+ xen_blkif_put(blkif);
}
}
@@ -1240,6 +1259,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
* below (in "!bio") if we are handling a BLKIF_OP_DISCARD.
*/
xen_blkif_get(blkif);
+ atomic_inc(&blkif->inflight);
for (i = 0; i < nseg; i++) {
while ((bio == NULL) ||
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 8d88075..be05277 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -57,7 +57,7 @@
#define MAX_INDIRECT_SEGMENTS 256
#define SEGS_PER_INDIRECT_FRAME \
- (PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
+ (PAGE_SIZE/sizeof(struct blkif_request_segment))
#define MAX_INDIRECT_PAGES \
((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
#define INDIRECT_PAGES(_segs) \
@@ -278,6 +278,7 @@ struct xen_blkif {
/* for barrier (drain) requests */
struct completion drain_complete;
atomic_t drain;
+ atomic_t inflight;
/* One thread per one blkif. */
struct task_struct *xenblkd;
unsigned int waiting_reqs;
@@ -376,6 +377,7 @@ int xen_blkif_xenbus_init(void);
irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
int xen_blkif_schedule(void *arg);
int xen_blkif_purge_persistent(void *arg);
+void xen_blkbk_free_caches(struct xen_blkif *blkif);
int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
struct backend_info *be, int state);
@@ -383,6 +385,7 @@ int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
int xen_blkbk_barrier(struct xenbus_transaction xbt,
struct backend_info *be, int state);
struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
+void xen_blkbk_unmap_purged_grants(struct work_struct *work);
static inline void blkif_get_x86_32_req(struct blkif_request *dst,
struct blkif_x86_32_request *src)
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index c2014a0..9a547e6 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -125,8 +125,11 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
blkif->persistent_gnts.rb_node = NULL;
spin_lock_init(&blkif->free_pages_lock);
INIT_LIST_HEAD(&blkif->free_pages);
+ INIT_LIST_HEAD(&blkif->persistent_purge_list);
blkif->free_pages_num = 0;
atomic_set(&blkif->persistent_gnt_in_use, 0);
+ atomic_set(&blkif->inflight, 0);
+ INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants);
INIT_LIST_HEAD(&blkif->pending_free);
@@ -259,6 +262,17 @@ static void xen_blkif_free(struct xen_blkif *blkif)
if (!atomic_dec_and_test(&blkif->refcnt))
BUG();
+ /* Remove all persistent grants and the cache of ballooned pages. */
+ xen_blkbk_free_caches(blkif);
+
+ /* Make sure everything is drained before shutting down */
+ BUG_ON(blkif->persistent_gnt_c != 0);
+ BUG_ON(atomic_read(&blkif->persistent_gnt_in_use) != 0);
+ BUG_ON(blkif->free_pages_num != 0);
+ BUG_ON(!list_empty(&blkif->persistent_purge_list));
+ BUG_ON(!list_empty(&blkif->free_pages));
+ BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));
+
/* Check that there is no request in use */
list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) {
list_del(&req->free_list);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8dcfb54..efe1b47 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -162,7 +162,7 @@ static DEFINE_SPINLOCK(minor_lock);
#define DEV_NAME "xvd" /* name in /dev */
#define SEGS_PER_INDIRECT_FRAME \
- (PAGE_SIZE/sizeof(struct blkif_request_segment_aligned))
+ (PAGE_SIZE/sizeof(struct blkif_request_segment))
#define INDIRECT_GREFS(_segs) \
((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
@@ -393,7 +393,7 @@ static int blkif_queue_request(struct request *req)
unsigned long id;
unsigned int fsect, lsect;
int i, ref, n;
- struct blkif_request_segment_aligned *segments = NULL;
+ struct blkif_request_segment *segments = NULL;
/*
* Used to store if we are able to queue the request by just using
@@ -550,7 +550,7 @@ static int blkif_queue_request(struct request *req)
} else {
n = i % SEGS_PER_INDIRECT_FRAME;
segments[n] =
- (struct blkif_request_segment_aligned) {
+ (struct blkif_request_segment) {
.gref = ref,
.first_sect = fsect,
.last_sect = lsect };
@@ -1904,13 +1904,16 @@ static void blkback_changed(struct xenbus_device *dev,
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
case XenbusStateUnknown:
- case XenbusStateClosed:
break;
case XenbusStateConnected:
blkfront_connect(info);
break;
+ case XenbusStateClosed:
+ if (dev->state == XenbusStateClosed)
+ break;
+ /* Missed the backend's Closing state -- fallthrough */
case XenbusStateClosing:
blkfront_closing(info);
break;