Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
Revert "block: recursive merge requests"
block: Stop using macro stubs for the bio data integrity calls
blockdev: convert some macros to static inlines
fs: remove unneeded plug in mpage_readpages()
block: Add BLKROTATIONAL ioctl
block: Introduce blk_set_stacking_limits function
block: remove WARN_ON_ONCE() in exit_io_context()
block: an exiting task should be allowed to create io_context
block: ioc_cgroup_changed() needs to be exported
block: recursive merge requests
block, cfq: fix empty queue crash caused by request merge
block, cfq: move icq creation and rq->elv.icq association to block core
block, cfq: restructure io_cq creation path for io_context interface cleanup
block, cfq: move io_cq exit/release to blk-ioc.c
block, cfq: move icq cache management to block core
block, cfq: move io_cq lookup to blk-ioc.c
block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
block, cfq: reorganize cfq_io_context into generic and cfq specific parts
block: remove elevator_queue->ops
block: reorder elevator switch sequence
...
Fix up conflicts in:
- block/blk-cgroup.c
Switch from can_attach_task to can_attach
- block/cfq-iosched.c
conflict with now removed cic index changes (we now use q->id instead)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b8c143d..fa8f263 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1655,11 +1655,12 @@
struct io_context *ioc;
cgroup_taskset_for_each(task, cgrp, tset) {
- task_lock(task);
- ioc = task->io_context;
- if (ioc)
- ioc->cgroup_changed = 1;
- task_unlock(task);
+ /* we don't lose anything even if ioc allocation fails */
+ ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
+ if (ioc) {
+ ioc_cgroup_changed(ioc);
+ put_io_context(ioc, NULL);
+ }
}
}
diff --git a/block/blk-core.c b/block/blk-core.c
index 15de223..e6c05a9 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,6 +39,8 @@
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
+DEFINE_IDA(blk_queue_ida);
+
/*
* For the allocated request tables
*/
@@ -358,7 +360,8 @@
void blk_drain_queue(struct request_queue *q, bool drain_all)
{
while (true) {
- int nr_rqs;
+ bool drain = false;
+ int i;
spin_lock_irq(q->queue_lock);
@@ -375,14 +378,25 @@
if (!list_empty(&q->queue_head))
__blk_run_queue(q);
- if (drain_all)
- nr_rqs = q->rq.count[0] + q->rq.count[1];
- else
- nr_rqs = q->rq.elvpriv;
+ drain |= q->rq.elvpriv;
+
+ /*
+ * Unfortunately, requests are queued at and tracked from
+ * multiple places and there's no single counter which can
+ * be drained. Check all the queues and counters.
+ */
+ if (drain_all) {
+ drain |= !list_empty(&q->queue_head);
+ for (i = 0; i < 2; i++) {
+ drain |= q->rq.count[i];
+ drain |= q->in_flight[i];
+ drain |= !list_empty(&q->flush_queue[i]);
+ }
+ }
spin_unlock_irq(q->queue_lock);
- if (!nr_rqs)
+ if (!drain)
break;
msleep(10);
}
@@ -469,6 +483,10 @@
if (!q)
return NULL;
+ q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL);
+ if (q->id < 0)
+ goto fail_q;
+
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
@@ -477,20 +495,17 @@
q->node = node_id;
err = bdi_init(&q->backing_dev_info);
- if (err) {
- kmem_cache_free(blk_requestq_cachep, q);
- return NULL;
- }
+ if (err)
+ goto fail_id;
- if (blk_throtl_init(q)) {
- kmem_cache_free(blk_requestq_cachep, q);
- return NULL;
- }
+ if (blk_throtl_init(q))
+ goto fail_id;
setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
laptop_mode_timer_fn, (unsigned long) q);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->icq_list);
INIT_LIST_HEAD(&q->flush_queue[0]);
INIT_LIST_HEAD(&q->flush_queue[1]);
INIT_LIST_HEAD(&q->flush_data_in_flight);
@@ -508,6 +523,12 @@
q->queue_lock = &q->__queue_lock;
return q;
+
+fail_id:
+ ida_simple_remove(&blk_queue_ida, q->id);
+fail_q:
+ kmem_cache_free(blk_requestq_cachep, q);
+ return NULL;
}
EXPORT_SYMBOL(blk_alloc_queue_node);
@@ -605,26 +626,31 @@
}
EXPORT_SYMBOL(blk_init_allocated_queue);
-int blk_get_queue(struct request_queue *q)
+bool blk_get_queue(struct request_queue *q)
{
- if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
- kobject_get(&q->kobj);
- return 0;
+ if (likely(!blk_queue_dead(q))) {
+ __blk_get_queue(q);
+ return true;
}
- return 1;
+ return false;
}
EXPORT_SYMBOL(blk_get_queue);
static inline void blk_free_request(struct request_queue *q, struct request *rq)
{
- if (rq->cmd_flags & REQ_ELVPRIV)
+ if (rq->cmd_flags & REQ_ELVPRIV) {
elv_put_request(q, rq);
+ if (rq->elv.icq)
+ put_io_context(rq->elv.icq->ioc, q);
+ }
+
mempool_free(rq, q->rq.rq_pool);
}
static struct request *
-blk_alloc_request(struct request_queue *q, unsigned int flags, gfp_t gfp_mask)
+blk_alloc_request(struct request_queue *q, struct io_cq *icq,
+ unsigned int flags, gfp_t gfp_mask)
{
struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
@@ -635,10 +661,15 @@
rq->cmd_flags = flags | REQ_ALLOCED;
- if ((flags & REQ_ELVPRIV) &&
- unlikely(elv_set_request(q, rq, gfp_mask))) {
- mempool_free(rq, q->rq.rq_pool);
- return NULL;
+ if (flags & REQ_ELVPRIV) {
+ rq->elv.icq = icq;
+ if (unlikely(elv_set_request(q, rq, gfp_mask))) {
+ mempool_free(rq, q->rq.rq_pool);
+ return NULL;
+ }
+ /* @rq->elv.icq holds on to io_context until @rq is freed */
+ if (icq)
+ get_io_context(icq->ioc);
}
return rq;
@@ -750,11 +781,17 @@
{
struct request *rq = NULL;
struct request_list *rl = &q->rq;
- struct io_context *ioc = NULL;
+ struct elevator_type *et;
+ struct io_context *ioc;
+ struct io_cq *icq = NULL;
const bool is_sync = rw_is_sync(rw_flags) != 0;
+ bool retried = false;
int may_queue;
+retry:
+ et = q->elevator->type;
+ ioc = current->io_context;
- if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+ if (unlikely(blk_queue_dead(q)))
return NULL;
may_queue = elv_may_queue(q, rw_flags);
@@ -763,7 +800,20 @@
if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) {
if (rl->count[is_sync]+1 >= q->nr_requests) {
- ioc = current_io_context(GFP_ATOMIC, q->node);
+ /*
+ * We want ioc to record batching state. If it's
+ * not already there, creating a new one requires
+ * dropping queue_lock, which in turn requires
+ * retesting conditions to avoid queue hang.
+ */
+ if (!ioc && !retried) {
+ spin_unlock_irq(q->queue_lock);
+ create_io_context(current, gfp_mask, q->node);
+ spin_lock_irq(q->queue_lock);
+ retried = true;
+ goto retry;
+ }
+
/*
* The queue will fill after this allocation, so set
* it as full, and mark this process as "batching".
@@ -799,17 +849,36 @@
rl->count[is_sync]++;
rl->starved[is_sync] = 0;
+ /*
+ * Decide whether the new request will be managed by elevator. If
+ * so, mark @rw_flags and increment elvpriv. Non-zero elvpriv will
+ * prevent the current elevator from being destroyed until the new
+ * request is freed. This guarantees icq's won't be destroyed and
+ * makes creating new ones safe.
+ *
+ * Also, lookup icq while holding queue_lock. If it doesn't exist,
+ * it will be created after releasing queue_lock.
+ */
if (blk_rq_should_init_elevator(bio) &&
!test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags)) {
rw_flags |= REQ_ELVPRIV;
rl->elvpriv++;
+ if (et->icq_cache && ioc)
+ icq = ioc_lookup_icq(ioc, q);
}
if (blk_queue_io_stat(q))
rw_flags |= REQ_IO_STAT;
spin_unlock_irq(q->queue_lock);
- rq = blk_alloc_request(q, rw_flags, gfp_mask);
+ /* create icq if missing */
+ if (unlikely(et->icq_cache && !icq))
+ icq = ioc_create_icq(q, gfp_mask);
+
+ /* rqs are guaranteed to have icq on elv_set_request() if requested */
+ if (likely(!et->icq_cache || icq))
+ rq = blk_alloc_request(q, icq, rw_flags, gfp_mask);
+
if (unlikely(!rq)) {
/*
* Allocation failed presumably due to memory. Undo anything
@@ -871,10 +940,9 @@
rq = get_request(q, rw_flags, bio, GFP_NOIO);
while (!rq) {
DEFINE_WAIT(wait);
- struct io_context *ioc;
struct request_list *rl = &q->rq;
- if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+ if (unlikely(blk_queue_dead(q)))
return NULL;
prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
@@ -891,8 +959,8 @@
* up to a big batch of them for a small period time.
* See ioc_batching, ioc_set_batching
*/
- ioc = current_io_context(GFP_NOIO, q->node);
- ioc_set_batching(q, ioc);
+ create_io_context(current, GFP_NOIO, q->node);
+ ioc_set_batching(q, current->io_context);
spin_lock_irq(q->queue_lock);
finish_wait(&rl->wait[is_sync], &wait);
@@ -1009,54 +1077,6 @@
__elv_add_request(q, rq, where);
}
-/**
- * blk_insert_request - insert a special request into a request queue
- * @q: request queue where request should be inserted
- * @rq: request to be inserted
- * @at_head: insert request at head or tail of queue
- * @data: private data
- *
- * Description:
- * Many block devices need to execute commands asynchronously, so they don't
- * block the whole kernel from preemption during request execution. This is
- * accomplished normally by inserting aritficial requests tagged as
- * REQ_TYPE_SPECIAL in to the corresponding request queue, and letting them
- * be scheduled for actual execution by the request queue.
- *
- * We have the option of inserting the head or the tail of the queue.
- * Typically we use the tail for new ioctls and so forth. We use the head
- * of the queue for things like a QUEUE_FULL message from a device, or a
- * host that is unable to accept a particular command.
- */
-void blk_insert_request(struct request_queue *q, struct request *rq,
- int at_head, void *data)
-{
- int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
- unsigned long flags;
-
- /*
- * tell I/O scheduler that this isn't a regular read/write (ie it
- * must not attempt merges on this) and that it acts as a soft
- * barrier
- */
- rq->cmd_type = REQ_TYPE_SPECIAL;
-
- rq->special = data;
-
- spin_lock_irqsave(q->queue_lock, flags);
-
- /*
- * If command is tagged, release the tag
- */
- if (blk_rq_tagged(rq))
- blk_queue_end_tag(q, rq);
-
- add_acct_request(q, rq, where);
- __blk_run_queue(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-EXPORT_SYMBOL(blk_insert_request);
-
static void part_round_stats_single(int cpu, struct hd_struct *part,
unsigned long now)
{
@@ -1766,6 +1786,10 @@
return -EIO;
spin_lock_irqsave(q->queue_lock, flags);
+ if (unlikely(blk_queue_dead(q))) {
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ return -ENODEV;
+ }
/*
* Submitting request must be dequeued before calling this function
@@ -2740,6 +2764,14 @@
trace_block_unplug(q, depth, !from_schedule);
/*
+ * Don't mess with dead queue.
+ */
+ if (unlikely(blk_queue_dead(q))) {
+ spin_unlock(q->queue_lock);
+ return;
+ }
+
+ /*
* If we are punting this to kblockd, then we can safely drop
* the queue_lock before waking kblockd (which needs to take
* this lock).
@@ -2815,6 +2847,15 @@
depth = 0;
spin_lock(q->queue_lock);
}
+
+ /*
+ * Short-circuit if @q is dead
+ */
+ if (unlikely(blk_queue_dead(q))) {
+ __blk_end_request_all(rq, -ENODEV);
+ continue;
+ }
+
/*
* rq is already accounted, so use raw insert
*/
diff --git a/block/blk-exec.c b/block/blk-exec.c
index a1ebceb..fb2cbd5 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -50,7 +50,11 @@
{
int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
- if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+ WARN_ON(irqs_disabled());
+ spin_lock_irq(q->queue_lock);
+
+ if (unlikely(blk_queue_dead(q))) {
+ spin_unlock_irq(q->queue_lock);
rq->errors = -ENXIO;
if (rq->end_io)
rq->end_io(rq, rq->errors);
@@ -59,8 +63,6 @@
rq->rq_disk = bd_disk;
rq->end_io = done;
- WARN_ON(irqs_disabled());
- spin_lock_irq(q->queue_lock);
__elv_add_request(q, rq, where);
__blk_run_queue(q);
/* the queue is stopped so it won't be run */
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 6f9bbd9..27a06e0 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -16,54 +16,215 @@
*/
static struct kmem_cache *iocontext_cachep;
-static void cfq_dtor(struct io_context *ioc)
+/**
+ * get_io_context - increment reference count to io_context
+ * @ioc: io_context to get
+ *
+ * Increment reference count to @ioc.
+ */
+void get_io_context(struct io_context *ioc)
{
- if (!hlist_empty(&ioc->cic_list)) {
- struct cfq_io_context *cic;
+ BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+ atomic_long_inc(&ioc->refcount);
+}
+EXPORT_SYMBOL(get_io_context);
- cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
- cic_list);
- cic->dtor(ioc);
- }
+/*
+ * Releasing ioc may nest into another put_io_context() leading to nested
+ * fast path release. As the ioc's can't be the same, this is okay but
+ * makes lockdep whine. Keep track of nesting and use it as subclass.
+ */
+#ifdef CONFIG_LOCKDEP
+#define ioc_release_depth(q) ((q) ? (q)->ioc_release_depth : 0)
+#define ioc_release_depth_inc(q) (q)->ioc_release_depth++
+#define ioc_release_depth_dec(q) (q)->ioc_release_depth--
+#else
+#define ioc_release_depth(q) 0
+#define ioc_release_depth_inc(q) do { } while (0)
+#define ioc_release_depth_dec(q) do { } while (0)
+#endif
+
+static void icq_free_icq_rcu(struct rcu_head *head)
+{
+ struct io_cq *icq = container_of(head, struct io_cq, __rcu_head);
+
+ kmem_cache_free(icq->__rcu_icq_cache, icq);
}
/*
- * IO Context helper functions. put_io_context() returns 1 if there are no
- * more users of this io context, 0 otherwise.
+ * Exit and free an icq. Called with both ioc and q locked.
*/
-int put_io_context(struct io_context *ioc)
+static void ioc_exit_icq(struct io_cq *icq)
{
- if (ioc == NULL)
- return 1;
+ struct io_context *ioc = icq->ioc;
+ struct request_queue *q = icq->q;
+ struct elevator_type *et = q->elevator->type;
- BUG_ON(atomic_long_read(&ioc->refcount) == 0);
+ lockdep_assert_held(&ioc->lock);
+ lockdep_assert_held(q->queue_lock);
- if (atomic_long_dec_and_test(&ioc->refcount)) {
- rcu_read_lock();
- cfq_dtor(ioc);
- rcu_read_unlock();
+ radix_tree_delete(&ioc->icq_tree, icq->q->id);
+ hlist_del_init(&icq->ioc_node);
+ list_del_init(&icq->q_node);
- kmem_cache_free(iocontext_cachep, ioc);
- return 1;
+ /*
+ * Both setting lookup hint to and clearing it from @icq are done
+ * under queue_lock. If it's not pointing to @icq now, it never
+ * will. Hint assignment itself can race safely.
+ */
+ if (rcu_dereference_raw(ioc->icq_hint) == icq)
+ rcu_assign_pointer(ioc->icq_hint, NULL);
+
+ if (et->ops.elevator_exit_icq_fn) {
+ ioc_release_depth_inc(q);
+ et->ops.elevator_exit_icq_fn(icq);
+ ioc_release_depth_dec(q);
}
- return 0;
+
+ /*
+ * @icq->q might have gone away by the time RCU callback runs
+ * making it impossible to determine icq_cache. Record it in @icq.
+ */
+ icq->__rcu_icq_cache = et->icq_cache;
+ call_rcu(&icq->__rcu_head, icq_free_icq_rcu);
+}
+
+/*
+ * Slow path for ioc release in put_io_context(). Performs double-lock
+ * dancing to unlink all icq's and then frees ioc.
+ */
+static void ioc_release_fn(struct work_struct *work)
+{
+ struct io_context *ioc = container_of(work, struct io_context,
+ release_work);
+ struct request_queue *last_q = NULL;
+
+ spin_lock_irq(&ioc->lock);
+
+ while (!hlist_empty(&ioc->icq_list)) {
+ struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+ struct io_cq, ioc_node);
+ struct request_queue *this_q = icq->q;
+
+ if (this_q != last_q) {
+ /*
+ * Need to switch to @this_q. Once we release
+ * @ioc->lock, it can go away along with @cic.
+ * Hold on to it.
+ */
+ __blk_get_queue(this_q);
+
+ /*
+ * blk_put_queue() might sleep thanks to kobject
+ * idiocy. Always release both locks, put and
+ * restart.
+ */
+ if (last_q) {
+ spin_unlock(last_q->queue_lock);
+ spin_unlock_irq(&ioc->lock);
+ blk_put_queue(last_q);
+ } else {
+ spin_unlock_irq(&ioc->lock);
+ }
+
+ last_q = this_q;
+ spin_lock_irq(this_q->queue_lock);
+ spin_lock(&ioc->lock);
+ continue;
+ }
+ ioc_exit_icq(icq);
+ }
+
+ if (last_q) {
+ spin_unlock(last_q->queue_lock);
+ spin_unlock_irq(&ioc->lock);
+ blk_put_queue(last_q);
+ } else {
+ spin_unlock_irq(&ioc->lock);
+ }
+
+ kmem_cache_free(iocontext_cachep, ioc);
+}
+
+/**
+ * put_io_context - put a reference of io_context
+ * @ioc: io_context to put
+ * @locked_q: request_queue the caller is holding queue_lock of (hint)
+ *
+ * Decrement reference count of @ioc and release it if the count reaches
+ * zero. If the caller is holding queue_lock of a queue, it can indicate
+ * that with @locked_q. This is an optimization hint and the caller is
+ * allowed to pass in %NULL even when it's holding a queue_lock.
+ */
+void put_io_context(struct io_context *ioc, struct request_queue *locked_q)
+{
+ struct request_queue *last_q = locked_q;
+ unsigned long flags;
+
+ if (ioc == NULL)
+ return;
+
+ BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+ if (locked_q)
+ lockdep_assert_held(locked_q->queue_lock);
+
+ if (!atomic_long_dec_and_test(&ioc->refcount))
+ return;
+
+ /*
+ * Destroy @ioc. This is a bit messy because icq's are chained
+ * from both ioc and queue, and ioc->lock nests inside queue_lock.
+ * The inner ioc->lock should be held to walk our icq_list and then
+ * for each icq the outer matching queue_lock should be grabbed.
+ * ie. We need to do reverse-order double lock dancing.
+ *
+ * Another twist is that we are often called with one of the
+ * matching queue_locks held as indicated by @locked_q, which
+ * prevents performing double-lock dance for other queues.
+ *
+ * So, we do it in two stages. The fast path uses the queue_lock
+ * the caller is holding and, if other queues need to be accessed,
+ * uses trylock to avoid introducing locking dependency. This can
+ * handle most cases, especially if @ioc was performing IO on only
+ * single device.
+ *
+ * If trylock doesn't cut it, we defer to @ioc->release_work which
+ * can do all the double-locking dancing.
+ */
+ spin_lock_irqsave_nested(&ioc->lock, flags,
+ ioc_release_depth(locked_q));
+
+ while (!hlist_empty(&ioc->icq_list)) {
+ struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+ struct io_cq, ioc_node);
+ struct request_queue *this_q = icq->q;
+
+ if (this_q != last_q) {
+ if (last_q && last_q != locked_q)
+ spin_unlock(last_q->queue_lock);
+ last_q = NULL;
+
+ if (!spin_trylock(this_q->queue_lock))
+ break;
+ last_q = this_q;
+ continue;
+ }
+ ioc_exit_icq(icq);
+ }
+
+ if (last_q && last_q != locked_q)
+ spin_unlock(last_q->queue_lock);
+
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
+ /* if no icq is left, we're done; otherwise, kick release_work */
+ if (hlist_empty(&ioc->icq_list))
+ kmem_cache_free(iocontext_cachep, ioc);
+ else
+ schedule_work(&ioc->release_work);
}
EXPORT_SYMBOL(put_io_context);
-static void cfq_exit(struct io_context *ioc)
-{
- rcu_read_lock();
-
- if (!hlist_empty(&ioc->cic_list)) {
- struct cfq_io_context *cic;
-
- cic = hlist_entry(ioc->cic_list.first, struct cfq_io_context,
- cic_list);
- cic->exit(ioc);
- }
- rcu_read_unlock();
-}
-
/* Called by the exiting task */
void exit_io_context(struct task_struct *task)
{
@@ -74,86 +235,240 @@
task->io_context = NULL;
task_unlock(task);
- if (atomic_dec_and_test(&ioc->nr_tasks))
- cfq_exit(ioc);
-
- put_io_context(ioc);
+ atomic_dec(&ioc->nr_tasks);
+ put_io_context(ioc, NULL);
}
-struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
+/**
+ * ioc_clear_queue - break any ioc association with the specified queue
+ * @q: request_queue being cleared
+ *
+ * Walk @q->icq_list and exit all io_cq's. Must be called with @q locked.
+ */
+void ioc_clear_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+
+ while (!list_empty(&q->icq_list)) {
+ struct io_cq *icq = list_entry(q->icq_list.next,
+ struct io_cq, q_node);
+ struct io_context *ioc = icq->ioc;
+
+ spin_lock(&ioc->lock);
+ ioc_exit_icq(icq);
+ spin_unlock(&ioc->lock);
+ }
+}
+
+void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_flags,
+ int node)
{
struct io_context *ioc;
- ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node);
- if (ioc) {
- atomic_long_set(&ioc->refcount, 1);
- atomic_set(&ioc->nr_tasks, 1);
- spin_lock_init(&ioc->lock);
- ioc->ioprio_changed = 0;
- ioc->ioprio = 0;
- ioc->last_waited = 0; /* doesn't matter... */
- ioc->nr_batch_requests = 0; /* because this is 0 */
- INIT_RADIX_TREE(&ioc->radix_root, GFP_ATOMIC | __GFP_HIGH);
- INIT_HLIST_HEAD(&ioc->cic_list);
- ioc->ioc_data = NULL;
-#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
- ioc->cgroup_changed = 0;
-#endif
- }
+ ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO,
+ node);
+ if (unlikely(!ioc))
+ return;
- return ioc;
-}
-
-/*
- * If the current task has no IO context then create one and initialise it.
- * Otherwise, return its existing IO context.
- *
- * This returned IO context doesn't have a specifically elevated refcount,
- * but since the current task itself holds a reference, the context can be
- * used in general code, so long as it stays within `current` context.
- */
-struct io_context *current_io_context(gfp_t gfp_flags, int node)
-{
- struct task_struct *tsk = current;
- struct io_context *ret;
-
- ret = tsk->io_context;
- if (likely(ret))
- return ret;
-
- ret = alloc_io_context(gfp_flags, node);
- if (ret) {
- /* make sure set_task_ioprio() sees the settings above */
- smp_wmb();
- tsk->io_context = ret;
- }
-
- return ret;
-}
-
-/*
- * If the current task has no IO context then create one and initialise it.
- * If it does have a context, take a ref on it.
- *
- * This is always called in the context of the task which submitted the I/O.
- */
-struct io_context *get_io_context(gfp_t gfp_flags, int node)
-{
- struct io_context *ioc = NULL;
+ /* initialize */
+ atomic_long_set(&ioc->refcount, 1);
+ atomic_set(&ioc->nr_tasks, 1);
+ spin_lock_init(&ioc->lock);
+ INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC | __GFP_HIGH);
+ INIT_HLIST_HEAD(&ioc->icq_list);
+ INIT_WORK(&ioc->release_work, ioc_release_fn);
/*
- * Check for unlikely race with exiting task. ioc ref count is
- * zero when ioc is being detached.
+ * Try to install. ioc shouldn't be installed if someone else
+ * already did or @task, which isn't %current, is exiting. Note
+ * that we need to allow ioc creation on exiting %current as exit
+ * path may issue IOs from e.g. exit_files(). The exit path is
+ * responsible for not issuing IO after exit_io_context().
*/
- do {
- ioc = current_io_context(gfp_flags, node);
- if (unlikely(!ioc))
- break;
- } while (!atomic_long_inc_not_zero(&ioc->refcount));
-
- return ioc;
+ task_lock(task);
+ if (!task->io_context &&
+ (task == current || !(task->flags & PF_EXITING)))
+ task->io_context = ioc;
+ else
+ kmem_cache_free(iocontext_cachep, ioc);
+ task_unlock(task);
}
-EXPORT_SYMBOL(get_io_context);
+
+/**
+ * get_task_io_context - get io_context of a task
+ * @task: task of interest
+ * @gfp_flags: allocation flags, used if allocation is necessary
+ * @node: allocation node, used if allocation is necessary
+ *
+ * Return io_context of @task. If it doesn't exist, it is created with
+ * @gfp_flags and @node. The returned io_context has its reference count
+ * incremented.
+ *
+ * This function always goes through task_lock() and it's better to use
+ * %current->io_context + get_io_context() for %current.
+ */
+struct io_context *get_task_io_context(struct task_struct *task,
+ gfp_t gfp_flags, int node)
+{
+ struct io_context *ioc;
+
+ might_sleep_if(gfp_flags & __GFP_WAIT);
+
+ do {
+ task_lock(task);
+ ioc = task->io_context;
+ if (likely(ioc)) {
+ get_io_context(ioc);
+ task_unlock(task);
+ return ioc;
+ }
+ task_unlock(task);
+ } while (create_io_context(task, gfp_flags, node));
+
+ return NULL;
+}
+EXPORT_SYMBOL(get_task_io_context);
+
+/**
+ * ioc_lookup_icq - lookup io_cq from ioc
+ * @ioc: the associated io_context
+ * @q: the associated request_queue
+ *
+ * Look up io_cq associated with @ioc - @q pair from @ioc. Must be called
+ * with @q->queue_lock held.
+ */
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q)
+{
+ struct io_cq *icq;
+
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * icq's are indexed from @ioc using radix tree and hint pointer,
+ * both of which are protected with RCU. All removals are done
+ * holding both q and ioc locks, and we're holding q lock - if we
+ * find a icq which points to us, it's guaranteed to be valid.
+ */
+ rcu_read_lock();
+ icq = rcu_dereference(ioc->icq_hint);
+ if (icq && icq->q == q)
+ goto out;
+
+ icq = radix_tree_lookup(&ioc->icq_tree, q->id);
+ if (icq && icq->q == q)
+ rcu_assign_pointer(ioc->icq_hint, icq); /* allowed to race */
+ else
+ icq = NULL;
+out:
+ rcu_read_unlock();
+ return icq;
+}
+EXPORT_SYMBOL(ioc_lookup_icq);
+
+/**
+ * ioc_create_icq - create and link io_cq
+ * @q: request_queue of interest
+ * @gfp_mask: allocation mask
+ *
+ * Make sure io_cq linking %current->io_context and @q exists. If either
+ * io_context and/or icq don't exist, they will be created using @gfp_mask.
+ *
+ * The caller is responsible for ensuring @ioc won't go away and @q is
+ * alive and will stay alive until this function returns.
+ */
+struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask)
+{
+ struct elevator_type *et = q->elevator->type;
+ struct io_context *ioc;
+ struct io_cq *icq;
+
+ /* allocate stuff */
+ ioc = create_io_context(current, gfp_mask, q->node);
+ if (!ioc)
+ return NULL;
+
+ icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO,
+ q->node);
+ if (!icq)
+ return NULL;
+
+ if (radix_tree_preload(gfp_mask) < 0) {
+ kmem_cache_free(et->icq_cache, icq);
+ return NULL;
+ }
+
+ icq->ioc = ioc;
+ icq->q = q;
+ INIT_LIST_HEAD(&icq->q_node);
+ INIT_HLIST_NODE(&icq->ioc_node);
+
+ /* lock both q and ioc and try to link @icq */
+ spin_lock_irq(q->queue_lock);
+ spin_lock(&ioc->lock);
+
+ if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
+ hlist_add_head(&icq->ioc_node, &ioc->icq_list);
+ list_add(&icq->q_node, &q->icq_list);
+ if (et->ops.elevator_init_icq_fn)
+ et->ops.elevator_init_icq_fn(icq);
+ } else {
+ kmem_cache_free(et->icq_cache, icq);
+ icq = ioc_lookup_icq(ioc, q);
+ if (!icq)
+ printk(KERN_ERR "cfq: icq link failed!\n");
+ }
+
+ spin_unlock(&ioc->lock);
+ spin_unlock_irq(q->queue_lock);
+ radix_tree_preload_end();
+ return icq;
+}
+
+void ioc_set_changed(struct io_context *ioc, int which)
+{
+ struct io_cq *icq;
+ struct hlist_node *n;
+
+ hlist_for_each_entry(icq, n, &ioc->icq_list, ioc_node)
+ set_bit(which, &icq->changed);
+}
+
+/**
+ * ioc_ioprio_changed - notify ioprio change
+ * @ioc: io_context of interest
+ * @ioprio: new ioprio
+ *
+ * @ioc's ioprio has changed to @ioprio. Set %ICQ_IOPRIO_CHANGED for all
+ * icq's. iosched is responsible for checking the bit and applying it on
+ * request issue path.
+ */
+void ioc_ioprio_changed(struct io_context *ioc, int ioprio)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ioc->lock, flags);
+ ioc->ioprio = ioprio;
+ ioc_set_changed(ioc, ICQ_IOPRIO_CHANGED);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+}
+
+/**
+ * ioc_cgroup_changed - notify cgroup change
+ * @ioc: io_context of interest
+ *
+ * @ioc's cgroup has changed. Set %ICQ_CGROUP_CHANGED for all icq's.
+ * iosched is responsible for checking the bit and applying it on request
+ * issue path.
+ */
+void ioc_cgroup_changed(struct io_context *ioc)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ioc->lock, flags);
+ ioc_set_changed(ioc, ICQ_CGROUP_CHANGED);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+}
+EXPORT_SYMBOL(ioc_cgroup_changed);
static int __init blk_ioc_init(void)
{
diff --git a/block/blk-settings.c b/block/blk-settings.c
index fa1eb04..d3234fc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -104,9 +104,7 @@
* @lim: the queue_limits structure to reset
*
* Description:
- * Returns a queue_limit struct to its default state. Can be used by
- * stacking drivers like DM that stage table swaps and reuse an
- * existing device queue.
+ * Returns a queue_limit struct to its default state.
*/
void blk_set_default_limits(struct queue_limits *lim)
{
@@ -114,13 +112,12 @@
lim->max_integrity_segments = 0;
lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
- lim->max_sectors = BLK_DEF_MAX_SECTORS;
- lim->max_hw_sectors = INT_MAX;
+ lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
lim->max_discard_sectors = 0;
lim->discard_granularity = 0;
lim->discard_alignment = 0;
lim->discard_misaligned = 0;
- lim->discard_zeroes_data = 1;
+ lim->discard_zeroes_data = 0;
lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
lim->alignment_offset = 0;
@@ -131,6 +128,27 @@
EXPORT_SYMBOL(blk_set_default_limits);
/**
+ * blk_set_stacking_limits - set default limits for stacking devices
+ * @lim: the queue_limits structure to reset
+ *
+ * Description:
+ * Returns a queue_limit struct to its default state. Should be used
+ * by stacking drivers like DM that have no internal limits.
+ */
+void blk_set_stacking_limits(struct queue_limits *lim)
+{
+ blk_set_default_limits(lim);
+
+ /* Inherit limits from component devices */
+ lim->discard_zeroes_data = 1;
+ lim->max_segments = USHRT_MAX;
+ lim->max_hw_sectors = UINT_MAX;
+
+ lim->max_sectors = BLK_DEF_MAX_SECTORS;
+}
+EXPORT_SYMBOL(blk_set_stacking_limits);
+
+/**
* blk_queue_make_request - define an alternate make_request function for a device
* @q: the request queue for the device to be affected
* @mfn: the alternate make_request function
@@ -165,8 +183,6 @@
q->nr_batching = BLK_BATCH_REQ;
blk_set_default_limits(&q->limits);
- blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS);
- q->limits.discard_zeroes_data = 0;
/*
* by default assume old behaviour and bounce for any highmem page
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index e7f9f65..cf15001 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -425,7 +425,7 @@
if (!entry->show)
return -EIO;
mutex_lock(&q->sysfs_lock);
- if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
+ if (blk_queue_dead(q)) {
mutex_unlock(&q->sysfs_lock);
return -ENOENT;
}
@@ -447,7 +447,7 @@
q = container_of(kobj, struct request_queue, kobj);
mutex_lock(&q->sysfs_lock);
- if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
+ if (blk_queue_dead(q)) {
mutex_unlock(&q->sysfs_lock);
return -ENOENT;
}
@@ -479,8 +479,12 @@
blk_sync_queue(q);
- if (q->elevator)
+ if (q->elevator) {
+ spin_lock_irq(q->queue_lock);
+ ioc_clear_queue(q);
+ spin_unlock_irq(q->queue_lock);
elevator_exit(q->elevator);
+ }
blk_throtl_exit(q);
@@ -494,6 +498,8 @@
blk_trace_shutdown(q);
bdi_destroy(&q->backing_dev_info);
+
+ ida_simple_remove(&blk_queue_ida, q->id);
kmem_cache_free(blk_requestq_cachep, q);
}
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 4553245..5eed6a7 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -310,7 +310,7 @@
struct request_queue *q = td->queue;
/* no throttling for dead queue */
- if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+ if (unlikely(blk_queue_dead(q)))
return NULL;
rcu_read_lock();
@@ -335,7 +335,7 @@
spin_lock_irq(q->queue_lock);
/* Make sure @q is still alive */
- if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+ if (unlikely(blk_queue_dead(q))) {
kfree(tg);
return NULL;
}
diff --git a/block/blk.h b/block/blk.h
index 3f6551b..7efd772 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -1,6 +1,8 @@
#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H
+#include <linux/idr.h>
+
/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME (HZ/50UL)
@@ -9,6 +11,12 @@
extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;
+extern struct ida blk_queue_ida;
+
+static inline void __blk_get_queue(struct request_queue *q)
+{
+ kobject_get(&q->kobj);
+}
void init_request_from_bio(struct request *req, struct bio *bio);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
@@ -85,8 +93,8 @@
q->flush_queue_delayed = 1;
return NULL;
}
- if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
- !q->elevator->ops->elevator_dispatch_fn(q, 0))
+ if (unlikely(blk_queue_dead(q)) ||
+ !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
return NULL;
}
}
@@ -95,16 +103,16 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_activate_req_fn)
- e->ops->elevator_activate_req_fn(q, rq);
+ if (e->type->ops.elevator_activate_req_fn)
+ e->type->ops.elevator_activate_req_fn(q, rq);
}
static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_deactivate_req_fn)
- e->ops->elevator_deactivate_req_fn(q, rq);
+ if (e->type->ops.elevator_deactivate_req_fn)
+ e->type->ops.elevator_deactivate_req_fn(q, rq);
}
#ifdef CONFIG_FAIL_IO_TIMEOUT
@@ -119,8 +127,6 @@
}
#endif
-struct io_context *current_io_context(gfp_t gfp_flags, int node);
-
int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
int ll_front_merge_fn(struct request_queue *q, struct request *req,
@@ -189,6 +195,42 @@
(rq->cmd_flags & REQ_DISCARD));
}
+/*
+ * Internal io_context interface
+ */
+void get_io_context(struct io_context *ioc);
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
+struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask);
+void ioc_clear_queue(struct request_queue *q);
+
+void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask,
+ int node);
+
+/**
+ * create_io_context - try to create task->io_context
+ * @task: target task
+ * @gfp_mask: allocation mask
+ * @node: allocation node
+ *
+ * If @task->io_context is %NULL, allocate a new io_context and install it.
+ * Returns the current @task->io_context which may be %NULL if allocation
+ * failed.
+ *
+ * Note that this function can't be called with IRQ disabled because
+ * task_lock which protects @task->io_context is IRQ-unsafe.
+ */
+static inline struct io_context *create_io_context(struct task_struct *task,
+ gfp_t gfp_mask, int node)
+{
+ WARN_ON_ONCE(irqs_disabled());
+ if (unlikely(!task->io_context))
+ create_io_context_slowpath(task, gfp_mask, node);
+ return task->io_context;
+}
+
+/*
+ * Internal throttling interface
+ */
#ifdef CONFIG_BLK_DEV_THROTTLING
extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
extern void blk_throtl_drain(struct request_queue *q);
diff --git a/block/bsg.c b/block/bsg.c
index 9651ec7..4cf703f 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -769,12 +769,10 @@
struct file *file)
{
struct bsg_device *bd;
- int ret;
#ifdef BSG_DEBUG
unsigned char buf[32];
#endif
- ret = blk_get_queue(rq);
- if (ret)
+ if (!blk_get_queue(rq))
return ERR_PTR(-ENXIO);
bd = bsg_alloc_device();
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3548705..163263d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -14,6 +14,7 @@
#include <linux/rbtree.h>
#include <linux/ioprio.h>
#include <linux/blktrace_api.h>
+#include "blk.h"
#include "cfq.h"
/*
@@ -53,20 +54,11 @@
#define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
#define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8)
-#define RQ_CIC(rq) \
- ((struct cfq_io_context *) (rq)->elevator_private[0])
-#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private[1])
-#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private[2])
+#define RQ_CIC(rq) icq_to_cic((rq)->elv.icq)
+#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0])
+#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1])
static struct kmem_cache *cfq_pool;
-static struct kmem_cache *cfq_ioc_pool;
-
-static DEFINE_PER_CPU(unsigned long, cfq_ioc_count);
-static struct completion *ioc_gone;
-static DEFINE_SPINLOCK(ioc_gone_lock);
-
-static DEFINE_SPINLOCK(cic_index_lock);
-static DEFINE_IDA(cic_index_ida);
#define CFQ_PRIO_LISTS IOPRIO_BE_NR
#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
@@ -75,6 +67,14 @@
#define sample_valid(samples) ((samples) > 80)
#define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node)
+struct cfq_ttime {
+ unsigned long last_end_request;
+
+ unsigned long ttime_total;
+ unsigned long ttime_samples;
+ unsigned long ttime_mean;
+};
+
/*
* Most of our rbtree usage is for sorting with min extraction, so
* if we cache the leftmost node we don't have to walk down the tree
@@ -216,6 +216,12 @@
struct cfq_ttime ttime;
};
+struct cfq_io_cq {
+ struct io_cq icq; /* must be the first member */
+ struct cfq_queue *cfqq[2];
+ struct cfq_ttime ttime;
+};
+
/*
* Per block device queue structure
*/
@@ -267,7 +273,7 @@
struct work_struct unplug_work;
struct cfq_queue *active_queue;
- struct cfq_io_context *active_cic;
+ struct cfq_io_cq *active_cic;
/*
* async queue for each priority case
@@ -290,9 +296,6 @@
unsigned int cfq_group_idle;
unsigned int cfq_latency;
- unsigned int cic_index;
- struct list_head cic_list;
-
/*
* Fallback dummy cfqq for extreme OOM conditions
*/
@@ -464,37 +467,35 @@
static void cfq_dispatch_insert(struct request_queue *, struct request *);
static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool,
struct io_context *, gfp_t);
-static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *,
- struct io_context *);
-static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic,
- bool is_sync)
+static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq)
+{
+ /* cic->icq is the first member, %NULL will convert to %NULL */
+ return container_of(icq, struct cfq_io_cq, icq);
+}
+
+static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd,
+ struct io_context *ioc)
+{
+ if (ioc)
+ return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue));
+ return NULL;
+}
+
+static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync)
{
return cic->cfqq[is_sync];
}
-static inline void cic_set_cfqq(struct cfq_io_context *cic,
- struct cfq_queue *cfqq, bool is_sync)
+static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq,
+ bool is_sync)
{
cic->cfqq[is_sync] = cfqq;
}
-#define CIC_DEAD_KEY 1ul
-#define CIC_DEAD_INDEX_SHIFT 1
-
-static inline void *cfqd_dead_key(struct cfq_data *cfqd)
+static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic)
{
- return (void *)(cfqd->cic_index << CIC_DEAD_INDEX_SHIFT | CIC_DEAD_KEY);
-}
-
-static inline struct cfq_data *cic_to_cfqd(struct cfq_io_context *cic)
-{
- struct cfq_data *cfqd = cic->key;
-
- if (unlikely((unsigned long) cfqd & CIC_DEAD_KEY))
- return NULL;
-
- return cfqd;
+ return cic->icq.q->elevator->elevator_data;
}
/*
@@ -1561,7 +1562,7 @@
cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
{
struct task_struct *tsk = current;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic;
struct cfq_queue *cfqq;
cic = cfq_cic_lookup(cfqd, tsk->io_context);
@@ -1687,7 +1688,7 @@
struct bio *bio)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic;
struct cfq_queue *cfqq;
/*
@@ -1697,12 +1698,19 @@
return false;
/*
- * Lookup the cfqq that this bio will be queued with. Allow
- * merge only if rq is queued there.
+ * Lookup the cfqq that this bio will be queued with and allow
+ * merge only if rq is queued there. This function can be called
+ * from plug merge without queue_lock. In such cases, ioc of @rq
+ * and %current are guaranteed to be equal. Avoid lookup which
+ * requires queue_lock by using @rq's cic.
*/
- cic = cfq_cic_lookup(cfqd, current->io_context);
- if (!cic)
- return false;
+ if (current->io_context == RQ_CIC(rq)->icq.ioc) {
+ cic = RQ_CIC(rq);
+ } else {
+ cic = cfq_cic_lookup(cfqd, current->io_context);
+ if (!cic)
+ return false;
+ }
cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio));
return cfqq == RQ_CFQQ(rq);
@@ -1786,7 +1794,7 @@
cfqd->active_queue = NULL;
if (cfqd->active_cic) {
- put_io_context(cfqd->active_cic->ioc);
+ put_io_context(cfqd->active_cic->icq.ioc, cfqd->queue);
cfqd->active_cic = NULL;
}
}
@@ -2006,7 +2014,7 @@
static void cfq_arm_slice_timer(struct cfq_data *cfqd)
{
struct cfq_queue *cfqq = cfqd->active_queue;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic;
unsigned long sl, group_idle = 0;
/*
@@ -2041,7 +2049,7 @@
* task has exited, don't wait
*/
cic = cfqd->active_cic;
- if (!cic || !atomic_read(&cic->ioc->nr_tasks))
+ if (!cic || !atomic_read(&cic->icq.ioc->nr_tasks))
return;
/*
@@ -2592,9 +2600,9 @@
cfq_dispatch_insert(cfqd->queue, rq);
if (!cfqd->active_cic) {
- struct cfq_io_context *cic = RQ_CIC(rq);
+ struct cfq_io_cq *cic = RQ_CIC(rq);
- atomic_long_inc(&cic->ioc->refcount);
+ atomic_long_inc(&cic->icq.ioc->refcount);
cfqd->active_cic = cic;
}
@@ -2677,84 +2685,6 @@
cfq_put_cfqg(cfqg);
}
-/*
- * Call func for each cic attached to this ioc.
- */
-static void
-call_for_each_cic(struct io_context *ioc,
- void (*func)(struct io_context *, struct cfq_io_context *))
-{
- struct cfq_io_context *cic;
- struct hlist_node *n;
-
- rcu_read_lock();
-
- hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list)
- func(ioc, cic);
-
- rcu_read_unlock();
-}
-
-static void cfq_cic_free_rcu(struct rcu_head *head)
-{
- struct cfq_io_context *cic;
-
- cic = container_of(head, struct cfq_io_context, rcu_head);
-
- kmem_cache_free(cfq_ioc_pool, cic);
- elv_ioc_count_dec(cfq_ioc_count);
-
- if (ioc_gone) {
- /*
- * CFQ scheduler is exiting, grab exit lock and check
- * the pending io context count. If it hits zero,
- * complete ioc_gone and set it back to NULL
- */
- spin_lock(&ioc_gone_lock);
- if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) {
- complete(ioc_gone);
- ioc_gone = NULL;
- }
- spin_unlock(&ioc_gone_lock);
- }
-}
-
-static void cfq_cic_free(struct cfq_io_context *cic)
-{
- call_rcu(&cic->rcu_head, cfq_cic_free_rcu);
-}
-
-static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
-{
- unsigned long flags;
- unsigned long dead_key = (unsigned long) cic->key;
-
- BUG_ON(!(dead_key & CIC_DEAD_KEY));
-
- spin_lock_irqsave(&ioc->lock, flags);
- radix_tree_delete(&ioc->radix_root, dead_key >> CIC_DEAD_INDEX_SHIFT);
- hlist_del_rcu(&cic->cic_list);
- spin_unlock_irqrestore(&ioc->lock, flags);
-
- cfq_cic_free(cic);
-}
-
-/*
- * Must be called with rcu_read_lock() held or preemption otherwise disabled.
- * Only two callers of this - ->dtor() which is called with the rcu_read_lock(),
- * and ->trim() which is called with the task lock held
- */
-static void cfq_free_io_context(struct io_context *ioc)
-{
- /*
- * ioc->refcount is zero here, or we are called from elv_unregister(),
- * so no more cic's are allowed to be linked into this ioc. So it
- * should be ok to iterate over the known list, we will see all cic's
- * since no new ones are added.
- */
- call_for_each_cic(ioc, cic_free_func);
-}
-
static void cfq_put_cooperator(struct cfq_queue *cfqq)
{
struct cfq_queue *__cfqq, *next;
@@ -2788,27 +2718,17 @@
cfq_put_queue(cfqq);
}
-static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
- struct cfq_io_context *cic)
+static void cfq_init_icq(struct io_cq *icq)
{
- struct io_context *ioc = cic->ioc;
+ struct cfq_io_cq *cic = icq_to_cic(icq);
- list_del_init(&cic->queue_list);
+ cic->ttime.last_end_request = jiffies;
+}
- /*
- * Make sure dead mark is seen for dead queues
- */
- smp_wmb();
- cic->key = cfqd_dead_key(cfqd);
-
- rcu_read_lock();
- if (rcu_dereference(ioc->ioc_data) == cic) {
- rcu_read_unlock();
- spin_lock(&ioc->lock);
- rcu_assign_pointer(ioc->ioc_data, NULL);
- spin_unlock(&ioc->lock);
- } else
- rcu_read_unlock();
+static void cfq_exit_icq(struct io_cq *icq)
+{
+ struct cfq_io_cq *cic = icq_to_cic(icq);
+ struct cfq_data *cfqd = cic_to_cfqd(cic);
if (cic->cfqq[BLK_RW_ASYNC]) {
cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
@@ -2821,57 +2741,6 @@
}
}
-static void cfq_exit_single_io_context(struct io_context *ioc,
- struct cfq_io_context *cic)
-{
- struct cfq_data *cfqd = cic_to_cfqd(cic);
-
- if (cfqd) {
- struct request_queue *q = cfqd->queue;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
-
- /*
- * Ensure we get a fresh copy of the ->key to prevent
- * race between exiting task and queue
- */
- smp_read_barrier_depends();
- if (cic->key == cfqd)
- __cfq_exit_single_io_context(cfqd, cic);
-
- spin_unlock_irqrestore(q->queue_lock, flags);
- }
-}
-
-/*
- * The process that ioc belongs to has exited, we need to clean up
- * and put the internal structures we have that belongs to that process.
- */
-static void cfq_exit_io_context(struct io_context *ioc)
-{
- call_for_each_cic(ioc, cfq_exit_single_io_context);
-}
-
-static struct cfq_io_context *
-cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
-{
- struct cfq_io_context *cic;
-
- cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO,
- cfqd->queue->node);
- if (cic) {
- cic->ttime.last_end_request = jiffies;
- INIT_LIST_HEAD(&cic->queue_list);
- INIT_HLIST_NODE(&cic->cic_list);
- cic->dtor = cfq_free_io_context;
- cic->exit = cfq_exit_io_context;
- elv_ioc_count_inc(cfq_ioc_count);
- }
-
- return cic;
-}
-
static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
{
struct task_struct *tsk = current;
@@ -2914,21 +2783,18 @@
cfq_clear_cfqq_prio_changed(cfqq);
}
-static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic)
+static void changed_ioprio(struct cfq_io_cq *cic)
{
struct cfq_data *cfqd = cic_to_cfqd(cic);
struct cfq_queue *cfqq;
- unsigned long flags;
if (unlikely(!cfqd))
return;
- spin_lock_irqsave(cfqd->queue->queue_lock, flags);
-
cfqq = cic->cfqq[BLK_RW_ASYNC];
if (cfqq) {
struct cfq_queue *new_cfqq;
- new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc,
+ new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->icq.ioc,
GFP_ATOMIC);
if (new_cfqq) {
cic->cfqq[BLK_RW_ASYNC] = new_cfqq;
@@ -2939,14 +2805,6 @@
cfqq = cic->cfqq[BLK_RW_SYNC];
if (cfqq)
cfq_mark_cfqq_prio_changed(cfqq);
-
- spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
-}
-
-static void cfq_ioc_set_ioprio(struct io_context *ioc)
-{
- call_for_each_cic(ioc, changed_ioprio);
- ioc->ioprio_changed = 0;
}
static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
@@ -2970,11 +2828,10 @@
}
#ifdef CONFIG_CFQ_GROUP_IOSCHED
-static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic)
+static void changed_cgroup(struct cfq_io_cq *cic)
{
struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1);
struct cfq_data *cfqd = cic_to_cfqd(cic);
- unsigned long flags;
struct request_queue *q;
if (unlikely(!cfqd))
@@ -2982,8 +2839,6 @@
q = cfqd->queue;
- spin_lock_irqsave(q->queue_lock, flags);
-
if (sync_cfqq) {
/*
* Drop reference to sync queue. A new sync queue will be
@@ -2993,14 +2848,6 @@
cic_set_cfqq(cic, NULL, 1);
cfq_put_queue(sync_cfqq);
}
-
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-
-static void cfq_ioc_set_cgroup(struct io_context *ioc)
-{
- call_for_each_cic(ioc, changed_cgroup);
- ioc->cgroup_changed = 0;
}
#endif /* CONFIG_CFQ_GROUP_IOSCHED */
@@ -3009,7 +2856,7 @@
struct io_context *ioc, gfp_t gfp_mask)
{
struct cfq_queue *cfqq, *new_cfqq = NULL;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic;
struct cfq_group *cfqg;
retry:
@@ -3100,160 +2947,6 @@
return cfqq;
}
-/*
- * We drop cfq io contexts lazily, so we may find a dead one.
- */
-static void
-cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
- struct cfq_io_context *cic)
-{
- unsigned long flags;
-
- WARN_ON(!list_empty(&cic->queue_list));
- BUG_ON(cic->key != cfqd_dead_key(cfqd));
-
- spin_lock_irqsave(&ioc->lock, flags);
-
- BUG_ON(rcu_dereference_check(ioc->ioc_data,
- lockdep_is_held(&ioc->lock)) == cic);
-
- radix_tree_delete(&ioc->radix_root, cfqd->cic_index);
- hlist_del_rcu(&cic->cic_list);
- spin_unlock_irqrestore(&ioc->lock, flags);
-
- cfq_cic_free(cic);
-}
-
-static struct cfq_io_context *
-cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc)
-{
- struct cfq_io_context *cic;
- unsigned long flags;
-
- if (unlikely(!ioc))
- return NULL;
-
- rcu_read_lock();
-
- /*
- * we maintain a last-hit cache, to avoid browsing over the tree
- */
- cic = rcu_dereference(ioc->ioc_data);
- if (cic && cic->key == cfqd) {
- rcu_read_unlock();
- return cic;
- }
-
- do {
- cic = radix_tree_lookup(&ioc->radix_root, cfqd->cic_index);
- rcu_read_unlock();
- if (!cic)
- break;
- if (unlikely(cic->key != cfqd)) {
- cfq_drop_dead_cic(cfqd, ioc, cic);
- rcu_read_lock();
- continue;
- }
-
- spin_lock_irqsave(&ioc->lock, flags);
- rcu_assign_pointer(ioc->ioc_data, cic);
- spin_unlock_irqrestore(&ioc->lock, flags);
- break;
- } while (1);
-
- return cic;
-}
-
-/*
- * Add cic into ioc, using cfqd as the search key. This enables us to lookup
- * the process specific cfq io context when entered from the block layer.
- * Also adds the cic to a per-cfqd list, used when this queue is removed.
- */
-static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
- struct cfq_io_context *cic, gfp_t gfp_mask)
-{
- unsigned long flags;
- int ret;
-
- ret = radix_tree_preload(gfp_mask);
- if (!ret) {
- cic->ioc = ioc;
- cic->key = cfqd;
-
- spin_lock_irqsave(&ioc->lock, flags);
- ret = radix_tree_insert(&ioc->radix_root,
- cfqd->cic_index, cic);
- if (!ret)
- hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list);
- spin_unlock_irqrestore(&ioc->lock, flags);
-
- radix_tree_preload_end();
-
- if (!ret) {
- spin_lock_irqsave(cfqd->queue->queue_lock, flags);
- list_add(&cic->queue_list, &cfqd->cic_list);
- spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
- }
- }
-
- if (ret && ret != -EEXIST)
- printk(KERN_ERR "cfq: cic link failed!\n");
-
- return ret;
-}
-
-/*
- * Setup general io context and cfq io context. There can be several cfq
- * io contexts per general io context, if this process is doing io to more
- * than one device managed by cfq.
- */
-static struct cfq_io_context *
-cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
-{
- struct io_context *ioc = NULL;
- struct cfq_io_context *cic;
- int ret;
-
- might_sleep_if(gfp_mask & __GFP_WAIT);
-
- ioc = get_io_context(gfp_mask, cfqd->queue->node);
- if (!ioc)
- return NULL;
-
-retry:
- cic = cfq_cic_lookup(cfqd, ioc);
- if (cic)
- goto out;
-
- cic = cfq_alloc_io_context(cfqd, gfp_mask);
- if (cic == NULL)
- goto err;
-
- ret = cfq_cic_link(cfqd, ioc, cic, gfp_mask);
- if (ret == -EEXIST) {
- /* someone has linked cic to ioc already */
- cfq_cic_free(cic);
- goto retry;
- } else if (ret)
- goto err_free;
-
-out:
- smp_read_barrier_depends();
- if (unlikely(ioc->ioprio_changed))
- cfq_ioc_set_ioprio(ioc);
-
-#ifdef CONFIG_CFQ_GROUP_IOSCHED
- if (unlikely(ioc->cgroup_changed))
- cfq_ioc_set_cgroup(ioc);
-#endif
- return cic;
-err_free:
- cfq_cic_free(cic);
-err:
- put_io_context(ioc);
- return NULL;
-}
-
static void
__cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle)
{
@@ -3267,7 +2960,7 @@
static void
cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_io_context *cic)
+ struct cfq_io_cq *cic)
{
if (cfq_cfqq_sync(cfqq)) {
__cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle);
@@ -3305,7 +2998,7 @@
*/
static void
cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_io_context *cic)
+ struct cfq_io_cq *cic)
{
int old_idle, enable_idle;
@@ -3322,8 +3015,9 @@
if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE))
enable_idle = 0;
- else if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
- (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
+ else if (!atomic_read(&cic->icq.ioc->nr_tasks) ||
+ !cfqd->cfq_slice_idle ||
+ (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
enable_idle = 0;
else if (sample_valid(cic->ttime.ttime_samples)) {
if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle)
@@ -3455,7 +3149,7 @@
cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct request *rq)
{
- struct cfq_io_context *cic = RQ_CIC(rq);
+ struct cfq_io_cq *cic = RQ_CIC(rq);
cfqd->rq_queued++;
if (rq->cmd_flags & REQ_PRIO)
@@ -3508,7 +3202,7 @@
struct cfq_queue *cfqq = RQ_CFQQ(rq);
cfq_log_cfqq(cfqd, cfqq, "insert_request");
- cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc);
+ cfq_init_prio_data(cfqq, RQ_CIC(rq)->icq.ioc);
rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);
list_add_tail(&rq->queuelist, &cfqq->fifo);
@@ -3558,7 +3252,7 @@
static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
- struct cfq_io_context *cic = cfqd->active_cic;
+ struct cfq_io_cq *cic = cfqd->active_cic;
/* If the queue already has requests, don't wait */
if (!RB_EMPTY_ROOT(&cfqq->sort_list))
@@ -3695,7 +3389,7 @@
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct task_struct *tsk = current;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic;
struct cfq_queue *cfqq;
/*
@@ -3710,7 +3404,7 @@
cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
if (cfqq) {
- cfq_init_prio_data(cfqq, cic->ioc);
+ cfq_init_prio_data(cfqq, cic->icq.ioc);
return __cfq_may_queue(cfqq);
}
@@ -3731,21 +3425,17 @@
BUG_ON(!cfqq->allocated[rw]);
cfqq->allocated[rw]--;
- put_io_context(RQ_CIC(rq)->ioc);
-
- rq->elevator_private[0] = NULL;
- rq->elevator_private[1] = NULL;
-
/* Put down rq reference on cfqg */
cfq_put_cfqg(RQ_CFQG(rq));
- rq->elevator_private[2] = NULL;
+ rq->elv.priv[0] = NULL;
+ rq->elv.priv[1] = NULL;
cfq_put_queue(cfqq);
}
}
static struct cfq_queue *
-cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic,
+cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic,
struct cfq_queue *cfqq)
{
cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq);
@@ -3760,7 +3450,7 @@
* was the last process referring to said cfqq.
*/
static struct cfq_queue *
-split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq)
+split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq)
{
if (cfqq_process_refs(cfqq) == 1) {
cfqq->pid = current->pid;
@@ -3783,25 +3473,29 @@
cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
- struct cfq_io_context *cic;
+ struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq);
const int rw = rq_data_dir(rq);
const bool is_sync = rq_is_sync(rq);
struct cfq_queue *cfqq;
- unsigned long flags;
might_sleep_if(gfp_mask & __GFP_WAIT);
- cic = cfq_get_io_context(cfqd, gfp_mask);
+ spin_lock_irq(q->queue_lock);
- spin_lock_irqsave(q->queue_lock, flags);
-
- if (!cic)
- goto queue_fail;
+ /* handle changed notifications */
+ if (unlikely(cic->icq.changed)) {
+ if (test_and_clear_bit(ICQ_IOPRIO_CHANGED, &cic->icq.changed))
+ changed_ioprio(cic);
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ if (test_and_clear_bit(ICQ_CGROUP_CHANGED, &cic->icq.changed))
+ changed_cgroup(cic);
+#endif
+ }
new_queue:
cfqq = cic_to_cfqq(cic, is_sync);
if (!cfqq || cfqq == &cfqd->oom_cfqq) {
- cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask);
+ cfqq = cfq_get_queue(cfqd, is_sync, cic->icq.ioc, gfp_mask);
cic_set_cfqq(cic, cfqq, is_sync);
} else {
/*
@@ -3827,17 +3521,10 @@
cfqq->allocated[rw]++;
cfqq->ref++;
- rq->elevator_private[0] = cic;
- rq->elevator_private[1] = cfqq;
- rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ rq->elv.priv[0] = cfqq;
+ rq->elv.priv[1] = cfq_ref_get_cfqg(cfqq->cfqg);
+ spin_unlock_irq(q->queue_lock);
return 0;
-
-queue_fail:
- cfq_schedule_dispatch(cfqd);
- spin_unlock_irqrestore(q->queue_lock, flags);
- cfq_log(cfqd, "set_request fail");
- return 1;
}
static void cfq_kick_queue(struct work_struct *work)
@@ -3941,14 +3628,6 @@
if (cfqd->active_queue)
__cfq_slice_expired(cfqd, cfqd->active_queue, 0);
- while (!list_empty(&cfqd->cic_list)) {
- struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
- struct cfq_io_context,
- queue_list);
-
- __cfq_exit_single_io_context(cfqd, cic);
- }
-
cfq_put_async_queues(cfqd);
cfq_release_cfq_groups(cfqd);
@@ -3963,10 +3642,6 @@
cfq_shutdown_timer_wq(cfqd);
- spin_lock(&cic_index_lock);
- ida_remove(&cic_index_ida, cfqd->cic_index);
- spin_unlock(&cic_index_lock);
-
/*
* Wait for cfqg->blkg->key accessors to exit their grace periods.
* Do this wait only if there are other unlinked groups out
@@ -3988,24 +3663,6 @@
kfree(cfqd);
}
-static int cfq_alloc_cic_index(void)
-{
- int index, error;
-
- do {
- if (!ida_pre_get(&cic_index_ida, GFP_KERNEL))
- return -ENOMEM;
-
- spin_lock(&cic_index_lock);
- error = ida_get_new(&cic_index_ida, &index);
- spin_unlock(&cic_index_lock);
- if (error && error != -EAGAIN)
- return error;
- } while (error);
-
- return index;
-}
-
static void *cfq_init_queue(struct request_queue *q)
{
struct cfq_data *cfqd;
@@ -4013,23 +3670,9 @@
struct cfq_group *cfqg;
struct cfq_rb_root *st;
- i = cfq_alloc_cic_index();
- if (i < 0)
- return NULL;
-
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
- if (!cfqd) {
- spin_lock(&cic_index_lock);
- ida_remove(&cic_index_ida, i);
- spin_unlock(&cic_index_lock);
+ if (!cfqd)
return NULL;
- }
-
- /*
- * Don't need take queue_lock in the routine, since we are
- * initializing the ioscheduler, and nobody is using cfqd
- */
- cfqd->cic_index = i;
/* Init root service tree */
cfqd->grp_service_tree = CFQ_RB_ROOT;
@@ -4055,11 +3698,6 @@
if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
kfree(cfqg);
-
- spin_lock(&cic_index_lock);
- ida_remove(&cic_index_ida, cfqd->cic_index);
- spin_unlock(&cic_index_lock);
-
kfree(cfqd);
return NULL;
}
@@ -4091,8 +3729,6 @@
cfqd->oom_cfqq.ref++;
cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
- INIT_LIST_HEAD(&cfqd->cic_list);
-
cfqd->queue = q;
init_timer(&cfqd->idle_slice_timer);
@@ -4121,34 +3757,6 @@
return cfqd;
}
-static void cfq_slab_kill(void)
-{
- /*
- * Caller already ensured that pending RCU callbacks are completed,
- * so we should have no busy allocations at this point.
- */
- if (cfq_pool)
- kmem_cache_destroy(cfq_pool);
- if (cfq_ioc_pool)
- kmem_cache_destroy(cfq_ioc_pool);
-}
-
-static int __init cfq_slab_setup(void)
-{
- cfq_pool = KMEM_CACHE(cfq_queue, 0);
- if (!cfq_pool)
- goto fail;
-
- cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0);
- if (!cfq_ioc_pool)
- goto fail;
-
- return 0;
-fail:
- cfq_slab_kill();
- return -ENOMEM;
-}
-
/*
* sysfs parts below -->
*/
@@ -4254,15 +3862,18 @@
.elevator_completed_req_fn = cfq_completed_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
+ .elevator_init_icq_fn = cfq_init_icq,
+ .elevator_exit_icq_fn = cfq_exit_icq,
.elevator_set_req_fn = cfq_set_request,
.elevator_put_req_fn = cfq_put_request,
.elevator_may_queue_fn = cfq_may_queue,
.elevator_init_fn = cfq_init_queue,
.elevator_exit_fn = cfq_exit_queue,
- .trim = cfq_free_io_context,
},
+ .icq_size = sizeof(struct cfq_io_cq),
+ .icq_align = __alignof__(struct cfq_io_cq),
.elevator_attrs = cfq_attrs,
- .elevator_name = "cfq",
+ .elevator_name = "cfq",
.elevator_owner = THIS_MODULE,
};
@@ -4280,6 +3891,8 @@
static int __init cfq_init(void)
{
+ int ret;
+
/*
* could be 0 on HZ < 1000 setups
*/
@@ -4294,10 +3907,16 @@
#else
cfq_group_idle = 0;
#endif
- if (cfq_slab_setup())
+ cfq_pool = KMEM_CACHE(cfq_queue, 0);
+ if (!cfq_pool)
return -ENOMEM;
- elv_register(&iosched_cfq);
+ ret = elv_register(&iosched_cfq);
+ if (ret) {
+ kmem_cache_destroy(cfq_pool);
+ return ret;
+ }
+
blkio_policy_register(&blkio_policy_cfq);
return 0;
@@ -4305,21 +3924,9 @@
static void __exit cfq_exit(void)
{
- DECLARE_COMPLETION_ONSTACK(all_gone);
blkio_policy_unregister(&blkio_policy_cfq);
elv_unregister(&iosched_cfq);
- ioc_gone = &all_gone;
- /* ioc_gone's update must be visible before reading ioc_count */
- smp_wmb();
-
- /*
- * this also protects us from entering cfq_slab_kill() with
- * pending RCU callbacks
- */
- if (elv_ioc_count_read(cfq_ioc_count))
- wait_for_completion(&all_gone);
- ida_destroy(&cic_index_ida);
- cfq_slab_kill();
+ kmem_cache_destroy(cfq_pool);
}
module_init(cfq_init);
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 7b72502..7c668c8 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -719,6 +719,9 @@
case BLKSECTGET:
return compat_put_ushort(arg,
queue_max_sectors(bdev_get_queue(bdev)));
+ case BLKROTATIONAL:
+ return compat_put_ushort(arg,
+ !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET: /* compatible, but no compat_ptr (!) */
case BLKFRASET:
if (!capable(CAP_SYS_ADMIN))
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index c644137..7bf12d7 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -448,9 +448,7 @@
static int __init deadline_init(void)
{
- elv_register(&iosched_deadline);
-
- return 0;
+ return elv_register(&iosched_deadline);
}
static void __exit deadline_exit(void)
diff --git a/block/elevator.c b/block/elevator.c
index 66343d6..91e18f8 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -61,8 +61,8 @@
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_allow_merge_fn)
- return e->ops->elevator_allow_merge_fn(q, rq, bio);
+ if (e->type->ops.elevator_allow_merge_fn)
+ return e->type->ops.elevator_allow_merge_fn(q, rq, bio);
return 1;
}
@@ -168,17 +168,13 @@
return e;
}
-static void *elevator_init_queue(struct request_queue *q,
- struct elevator_queue *eq)
+static int elevator_init_queue(struct request_queue *q,
+ struct elevator_queue *eq)
{
- return eq->ops->elevator_init_fn(q);
-}
-
-static void elevator_attach(struct request_queue *q, struct elevator_queue *eq,
- void *data)
-{
- q->elevator = eq;
- eq->elevator_data = data;
+ eq->elevator_data = eq->type->ops.elevator_init_fn(q);
+ if (eq->elevator_data)
+ return 0;
+ return -ENOMEM;
}
static char chosen_elevator[ELV_NAME_MAX];
@@ -207,8 +203,7 @@
if (unlikely(!eq))
goto err;
- eq->ops = &e->ops;
- eq->elevator_type = e;
+ eq->type = e;
kobject_init(&eq->kobj, &elv_ktype);
mutex_init(&eq->sysfs_lock);
@@ -232,7 +227,7 @@
struct elevator_queue *e;
e = container_of(kobj, struct elevator_queue, kobj);
- elevator_put(e->elevator_type);
+ elevator_put(e->type);
kfree(e->hash);
kfree(e);
}
@@ -241,7 +236,7 @@
{
struct elevator_type *e = NULL;
struct elevator_queue *eq;
- void *data;
+ int err;
if (unlikely(q->elevator))
return 0;
@@ -278,13 +273,13 @@
if (!eq)
return -ENOMEM;
- data = elevator_init_queue(q, eq);
- if (!data) {
+ err = elevator_init_queue(q, eq);
+ if (err) {
kobject_put(&eq->kobj);
- return -ENOMEM;
+ return err;
}
- elevator_attach(q, eq, data);
+ q->elevator = eq;
return 0;
}
EXPORT_SYMBOL(elevator_init);
@@ -292,9 +287,8 @@
void elevator_exit(struct elevator_queue *e)
{
mutex_lock(&e->sysfs_lock);
- if (e->ops->elevator_exit_fn)
- e->ops->elevator_exit_fn(e);
- e->ops = NULL;
+ if (e->type->ops.elevator_exit_fn)
+ e->type->ops.elevator_exit_fn(e);
mutex_unlock(&e->sysfs_lock);
kobject_put(&e->kobj);
@@ -504,8 +498,8 @@
return ELEVATOR_BACK_MERGE;
}
- if (e->ops->elevator_merge_fn)
- return e->ops->elevator_merge_fn(q, req, bio);
+ if (e->type->ops.elevator_merge_fn)
+ return e->type->ops.elevator_merge_fn(q, req, bio);
return ELEVATOR_NO_MERGE;
}
@@ -548,8 +542,8 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_merged_fn)
- e->ops->elevator_merged_fn(q, rq, type);
+ if (e->type->ops.elevator_merged_fn)
+ e->type->ops.elevator_merged_fn(q, rq, type);
if (type == ELEVATOR_BACK_MERGE)
elv_rqhash_reposition(q, rq);
@@ -563,8 +557,8 @@
struct elevator_queue *e = q->elevator;
const int next_sorted = next->cmd_flags & REQ_SORTED;
- if (next_sorted && e->ops->elevator_merge_req_fn)
- e->ops->elevator_merge_req_fn(q, rq, next);
+ if (next_sorted && e->type->ops.elevator_merge_req_fn)
+ e->type->ops.elevator_merge_req_fn(q, rq, next);
elv_rqhash_reposition(q, rq);
@@ -581,8 +575,8 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_bio_merged_fn)
- e->ops->elevator_bio_merged_fn(q, rq, bio);
+ if (e->type->ops.elevator_bio_merged_fn)
+ e->type->ops.elevator_bio_merged_fn(q, rq, bio);
}
void elv_requeue_request(struct request_queue *q, struct request *rq)
@@ -608,12 +602,12 @@
lockdep_assert_held(q->queue_lock);
- while (q->elevator->ops->elevator_dispatch_fn(q, 1))
+ while (q->elevator->type->ops.elevator_dispatch_fn(q, 1))
;
if (q->nr_sorted && printed++ < 10) {
printk(KERN_ERR "%s: forced dispatching is broken "
"(nr_sorted=%u), please report this\n",
- q->elevator->elevator_type->elevator_name, q->nr_sorted);
+ q->elevator->type->elevator_name, q->nr_sorted);
}
}
@@ -702,7 +696,7 @@
* rq cannot be accessed after calling
* elevator_add_req_fn.
*/
- q->elevator->ops->elevator_add_req_fn(q, rq);
+ q->elevator->type->ops.elevator_add_req_fn(q, rq);
break;
case ELEVATOR_INSERT_FLUSH:
@@ -731,8 +725,8 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_latter_req_fn)
- return e->ops->elevator_latter_req_fn(q, rq);
+ if (e->type->ops.elevator_latter_req_fn)
+ return e->type->ops.elevator_latter_req_fn(q, rq);
return NULL;
}
@@ -740,8 +734,8 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_former_req_fn)
- return e->ops->elevator_former_req_fn(q, rq);
+ if (e->type->ops.elevator_former_req_fn)
+ return e->type->ops.elevator_former_req_fn(q, rq);
return NULL;
}
@@ -749,10 +743,8 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_set_req_fn)
- return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
-
- rq->elevator_private[0] = NULL;
+ if (e->type->ops.elevator_set_req_fn)
+ return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask);
return 0;
}
@@ -760,16 +752,16 @@
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_put_req_fn)
- e->ops->elevator_put_req_fn(rq);
+ if (e->type->ops.elevator_put_req_fn)
+ e->type->ops.elevator_put_req_fn(rq);
}
int elv_may_queue(struct request_queue *q, int rw)
{
struct elevator_queue *e = q->elevator;
- if (e->ops->elevator_may_queue_fn)
- return e->ops->elevator_may_queue_fn(q, rw);
+ if (e->type->ops.elevator_may_queue_fn)
+ return e->type->ops.elevator_may_queue_fn(q, rw);
return ELV_MQUEUE_MAY;
}
@@ -804,8 +796,8 @@
if (blk_account_rq(rq)) {
q->in_flight[rq_is_sync(rq)]--;
if ((rq->cmd_flags & REQ_SORTED) &&
- e->ops->elevator_completed_req_fn)
- e->ops->elevator_completed_req_fn(q, rq);
+ e->type->ops.elevator_completed_req_fn)
+ e->type->ops.elevator_completed_req_fn(q, rq);
}
}
@@ -823,7 +815,7 @@
e = container_of(kobj, struct elevator_queue, kobj);
mutex_lock(&e->sysfs_lock);
- error = e->ops ? entry->show(e, page) : -ENOENT;
+ error = e->type ? entry->show(e, page) : -ENOENT;
mutex_unlock(&e->sysfs_lock);
return error;
}
@@ -841,7 +833,7 @@
e = container_of(kobj, struct elevator_queue, kobj);
mutex_lock(&e->sysfs_lock);
- error = e->ops ? entry->store(e, page, length) : -ENOENT;
+ error = e->type ? entry->store(e, page, length) : -ENOENT;
mutex_unlock(&e->sysfs_lock);
return error;
}
@@ -856,14 +848,13 @@
.release = elevator_release,
};
-int elv_register_queue(struct request_queue *q)
+int __elv_register_queue(struct request_queue *q, struct elevator_queue *e)
{
- struct elevator_queue *e = q->elevator;
int error;
error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
if (!error) {
- struct elv_fs_entry *attr = e->elevator_type->elevator_attrs;
+ struct elv_fs_entry *attr = e->type->elevator_attrs;
if (attr) {
while (attr->attr.name) {
if (sysfs_create_file(&e->kobj, &attr->attr))
@@ -876,31 +867,55 @@
}
return error;
}
-EXPORT_SYMBOL(elv_register_queue);
-static void __elv_unregister_queue(struct elevator_queue *e)
+int elv_register_queue(struct request_queue *q)
{
- kobject_uevent(&e->kobj, KOBJ_REMOVE);
- kobject_del(&e->kobj);
- e->registered = 0;
+ return __elv_register_queue(q, q->elevator);
}
+EXPORT_SYMBOL(elv_register_queue);
void elv_unregister_queue(struct request_queue *q)
{
- if (q)
- __elv_unregister_queue(q->elevator);
+ if (q) {
+ struct elevator_queue *e = q->elevator;
+
+ kobject_uevent(&e->kobj, KOBJ_REMOVE);
+ kobject_del(&e->kobj);
+ e->registered = 0;
+ }
}
EXPORT_SYMBOL(elv_unregister_queue);
-void elv_register(struct elevator_type *e)
+int elv_register(struct elevator_type *e)
{
char *def = "";
+ /* create icq_cache if requested */
+ if (e->icq_size) {
+ if (WARN_ON(e->icq_size < sizeof(struct io_cq)) ||
+ WARN_ON(e->icq_align < __alignof__(struct io_cq)))
+ return -EINVAL;
+
+ snprintf(e->icq_cache_name, sizeof(e->icq_cache_name),
+ "%s_io_cq", e->elevator_name);
+ e->icq_cache = kmem_cache_create(e->icq_cache_name, e->icq_size,
+ e->icq_align, 0, NULL);
+ if (!e->icq_cache)
+ return -ENOMEM;
+ }
+
+ /* register, don't allow duplicate names */
spin_lock(&elv_list_lock);
- BUG_ON(elevator_find(e->elevator_name));
+ if (elevator_find(e->elevator_name)) {
+ spin_unlock(&elv_list_lock);
+ if (e->icq_cache)
+ kmem_cache_destroy(e->icq_cache);
+ return -EBUSY;
+ }
list_add_tail(&e->list, &elv_list);
spin_unlock(&elv_list_lock);
+ /* print pretty message */
if (!strcmp(e->elevator_name, chosen_elevator) ||
(!*chosen_elevator &&
!strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
@@ -908,30 +923,26 @@
printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
def);
+ return 0;
}
EXPORT_SYMBOL_GPL(elv_register);
void elv_unregister(struct elevator_type *e)
{
- struct task_struct *g, *p;
-
- /*
- * Iterate every thread in the process to remove the io contexts.
- */
- if (e->ops.trim) {
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- task_lock(p);
- if (p->io_context)
- e->ops.trim(p->io_context);
- task_unlock(p);
- } while_each_thread(g, p);
- read_unlock(&tasklist_lock);
- }
-
+ /* unregister */
spin_lock(&elv_list_lock);
list_del_init(&e->list);
spin_unlock(&elv_list_lock);
+
+ /*
+ * Destroy icq_cache if it exists. icq's are RCU managed. Make
+ * sure all RCU operations are complete before proceeding.
+ */
+ if (e->icq_cache) {
+ rcu_barrier();
+ kmem_cache_destroy(e->icq_cache);
+ e->icq_cache = NULL;
+ }
}
EXPORT_SYMBOL_GPL(elv_unregister);
@@ -944,54 +955,41 @@
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
{
struct elevator_queue *old_elevator, *e;
- void *data;
int err;
- /*
- * Allocate new elevator
- */
+ /* allocate new elevator */
e = elevator_alloc(q, new_e);
if (!e)
return -ENOMEM;
- data = elevator_init_queue(q, e);
- if (!data) {
+ err = elevator_init_queue(q, e);
+ if (err) {
kobject_put(&e->kobj);
- return -ENOMEM;
+ return err;
}
- /*
- * Turn on BYPASS and drain all requests w/ elevator private data
- */
+ /* turn on BYPASS and drain all requests w/ elevator private data */
elv_quiesce_start(q);
- /*
- * Remember old elevator.
- */
- old_elevator = q->elevator;
-
- /*
- * attach and start new elevator
- */
- spin_lock_irq(q->queue_lock);
- elevator_attach(q, e, data);
- spin_unlock_irq(q->queue_lock);
-
- if (old_elevator->registered) {
- __elv_unregister_queue(old_elevator);
-
- err = elv_register_queue(q);
+ /* unregister old queue, register new one and kill old elevator */
+ if (q->elevator->registered) {
+ elv_unregister_queue(q);
+ err = __elv_register_queue(q, e);
if (err)
goto fail_register;
}
- /*
- * finally exit old elevator and turn off BYPASS.
- */
+ /* done, clear io_cq's, switch elevators and turn off BYPASS */
+ spin_lock_irq(q->queue_lock);
+ ioc_clear_queue(q);
+ old_elevator = q->elevator;
+ q->elevator = e;
+ spin_unlock_irq(q->queue_lock);
+
elevator_exit(old_elevator);
elv_quiesce_end(q);
- blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);
+ blk_add_trace_msg(q, "elv switch: %s", e->type->elevator_name);
return 0;
@@ -1001,7 +999,6 @@
* one again (along with re-adding the sysfs dir)
*/
elevator_exit(e);
- q->elevator = old_elevator;
elv_register_queue(q);
elv_quiesce_end(q);
@@ -1026,7 +1023,7 @@
return -EINVAL;
}
- if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name)) {
+ if (!strcmp(elevator_name, q->elevator->type->elevator_name)) {
elevator_put(e);
return 0;
}
@@ -1061,7 +1058,7 @@
if (!q->elevator || !blk_queue_stackable(q))
return sprintf(name, "none\n");
- elv = e->elevator_type;
+ elv = e->type;
spin_lock(&elv_list_lock);
list_for_each_entry(__e, &elv_list, list) {
diff --git a/block/genhd.c b/block/genhd.c
index 83e7c04..23b4f70 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -614,7 +614,7 @@
* Take an extra ref on queue which will be put on disk_release()
* so that it sticks around as long as @disk is there.
*/
- WARN_ON_ONCE(blk_get_queue(disk->queue));
+ WARN_ON_ONCE(!blk_get_queue(disk->queue));
retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
"bdi");
diff --git a/block/ioctl.c b/block/ioctl.c
index 4828fa3..ba15b2d 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -296,6 +296,8 @@
return put_uint(arg, bdev_discard_zeroes_data(bdev));
case BLKSECTGET:
return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
+ case BLKROTATIONAL:
+ return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET:
case BLKFRASET:
if(!capable(CAP_SYS_ADMIN))
diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index 06389e9..413a0b1 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -94,9 +94,7 @@
static int __init noop_init(void)
{
- elv_register(&elevator_noop);
-
- return 0;
+ return elv_register(&elevator_noop);
}
static void __exit noop_exit(void)