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-rw-r--r--block/blk-cgroup.c2
-rw-r--r--block/blk-core.c33
-rw-r--r--block/blk-ioc.c111
-rw-r--r--block/blk-merge.c37
-rw-r--r--block/blk.h2
-rw-r--r--block/bsg.c3
-rw-r--r--block/cfq-iosched.c24
-rw-r--r--block/elevator.c55
-rw-r--r--block/partitions/ldm.c11
9 files changed, 101 insertions, 177 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fa8f2630944..75642a352a8 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1659,7 +1659,7 @@ static void blkiocg_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
if (ioc) {
ioc_cgroup_changed(ioc);
- put_io_context(ioc, NULL);
+ put_io_context(ioc);
}
}
}
diff --git a/block/blk-core.c b/block/blk-core.c
index e6c05a97ee2..3a78b00edd7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -642,7 +642,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq)
if (rq->cmd_flags & REQ_ELVPRIV) {
elv_put_request(q, rq);
if (rq->elv.icq)
- put_io_context(rq->elv.icq->ioc, q);
+ put_io_context(rq->elv.icq->ioc);
}
mempool_free(rq, q->rq.rq_pool);
@@ -872,13 +872,15 @@ retry:
spin_unlock_irq(q->queue_lock);
/* create icq if missing */
- if (unlikely(et->icq_cache && !icq))
+ if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) {
icq = ioc_create_icq(q, gfp_mask);
+ if (!icq)
+ goto fail_icq;
+ }
- /* 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);
+ rq = blk_alloc_request(q, icq, rw_flags, gfp_mask);
+fail_icq:
if (unlikely(!rq)) {
/*
* Allocation failed presumably due to memory. Undo anything
@@ -1210,7 +1212,6 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
drive_stat_acct(req, 0);
- elv_bio_merged(q, req, bio);
return true;
}
@@ -1241,7 +1242,6 @@ static bool bio_attempt_front_merge(struct request_queue *q,
req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
drive_stat_acct(req, 0);
- elv_bio_merged(q, req, bio);
return true;
}
@@ -1255,13 +1255,12 @@ static bool bio_attempt_front_merge(struct request_queue *q,
* on %current's plugged list. Returns %true if merge was successful,
* otherwise %false.
*
- * This function is called without @q->queue_lock; however, elevator is
- * accessed iff there already are requests on the plugged list which in
- * turn guarantees validity of the elevator.
- *
- * Note that, on successful merge, elevator operation
- * elevator_bio_merged_fn() will be called without queue lock. Elevator
- * must be ready for this.
+ * Plugging coalesces IOs from the same issuer for the same purpose without
+ * going through @q->queue_lock. As such it's more of an issuing mechanism
+ * than scheduling, and the request, while may have elvpriv data, is not
+ * added on the elevator at this point. In addition, we don't have
+ * reliable access to the elevator outside queue lock. Only check basic
+ * merging parameters without querying the elevator.
*/
static bool attempt_plug_merge(struct request_queue *q, struct bio *bio,
unsigned int *request_count)
@@ -1280,10 +1279,10 @@ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio,
(*request_count)++;
- if (rq->q != q)
+ if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
- el_ret = elv_try_merge(rq, bio);
+ el_ret = blk_try_merge(rq, bio);
if (el_ret == ELEVATOR_BACK_MERGE) {
ret = bio_attempt_back_merge(q, rq, bio);
if (ret)
@@ -1345,12 +1344,14 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio)
el_ret = elv_merge(q, &req, bio);
if (el_ret == ELEVATOR_BACK_MERGE) {
if (bio_attempt_back_merge(q, req, bio)) {
+ elv_bio_merged(q, req, bio);
if (!attempt_back_merge(q, req))
elv_merged_request(q, req, el_ret);
goto out_unlock;
}
} else if (el_ret == ELEVATOR_FRONT_MERGE) {
if (bio_attempt_front_merge(q, req, bio)) {
+ elv_bio_merged(q, req, bio);
if (!attempt_front_merge(q, req))
elv_merged_request(q, req, el_ret);
goto out_unlock;
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 27a06e00eae..8b782a63c29 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -29,21 +29,6 @@ void get_io_context(struct io_context *ioc)
}
EXPORT_SYMBOL(get_io_context);
-/*
- * 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);
@@ -75,11 +60,8 @@ static void ioc_exit_icq(struct io_cq *icq)
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);
+ if (et->ops.elevator_exit_icq_fn)
et->ops.elevator_exit_icq_fn(icq);
- ioc_release_depth_dec(q);
- }
/*
* @icq->q might have gone away by the time RCU callback runs
@@ -98,8 +80,15 @@ 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;
+ unsigned long flags;
- spin_lock_irq(&ioc->lock);
+ /*
+ * Exiting icq may call into put_io_context() through elevator
+ * which will trigger lockdep warning. The ioc's are guaranteed to
+ * be different, use a different locking subclass here. Use
+ * irqsave variant as there's no spin_lock_irq_nested().
+ */
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
while (!hlist_empty(&ioc->icq_list)) {
struct io_cq *icq = hlist_entry(ioc->icq_list.first,
@@ -121,15 +110,15 @@ static void ioc_release_fn(struct work_struct *work)
*/
if (last_q) {
spin_unlock(last_q->queue_lock);
- spin_unlock_irq(&ioc->lock);
+ spin_unlock_irqrestore(&ioc->lock, flags);
blk_put_queue(last_q);
} else {
- spin_unlock_irq(&ioc->lock);
+ spin_unlock_irqrestore(&ioc->lock, flags);
}
last_q = this_q;
- spin_lock_irq(this_q->queue_lock);
- spin_lock(&ioc->lock);
+ spin_lock_irqsave(this_q->queue_lock, flags);
+ spin_lock_nested(&ioc->lock, 1);
continue;
}
ioc_exit_icq(icq);
@@ -137,10 +126,10 @@ static void ioc_release_fn(struct work_struct *work)
if (last_q) {
spin_unlock(last_q->queue_lock);
- spin_unlock_irq(&ioc->lock);
+ spin_unlock_irqrestore(&ioc->lock, flags);
blk_put_queue(last_q);
} else {
- spin_unlock_irq(&ioc->lock);
+ spin_unlock_irqrestore(&ioc->lock, flags);
}
kmem_cache_free(iocontext_cachep, ioc);
@@ -149,79 +138,29 @@ static void ioc_release_fn(struct work_struct *work)
/**
* 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.
+ * zero.
*/
-void put_io_context(struct io_context *ioc, struct request_queue *locked_q)
+void put_io_context(struct io_context *ioc)
{
- 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.
+ * Releasing ioc requires reverse order double locking and we may
+ * already be holding a queue_lock. Do it asynchronously from wq.
*/
- 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 (atomic_long_dec_and_test(&ioc->refcount)) {
+ spin_lock_irqsave(&ioc->lock, flags);
+ if (!hlist_empty(&ioc->icq_list))
+ schedule_work(&ioc->release_work);
+ spin_unlock_irqrestore(&ioc->lock, flags);
}
-
- 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);
@@ -236,7 +175,7 @@ void exit_io_context(struct task_struct *task)
task_unlock(task);
atomic_dec(&ioc->nr_tasks);
- put_io_context(ioc, NULL);
+ put_io_context(ioc);
}
/**
diff --git a/block/blk-merge.c b/block/blk-merge.c
index cfcc37cb222..160035f5488 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -471,3 +471,40 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
{
return attempt_merge(q, rq, next);
}
+
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
+{
+ if (!rq_mergeable(rq))
+ return false;
+
+ /* don't merge file system requests and discard requests */
+ if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
+ return false;
+
+ /* don't merge discard requests and secure discard requests */
+ if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+ return false;
+
+ /* different data direction or already started, don't merge */
+ if (bio_data_dir(bio) != rq_data_dir(rq))
+ return false;
+
+ /* must be same device and not a special request */
+ if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
+ return false;
+
+ /* only merge integrity protected bio into ditto rq */
+ if (bio_integrity(bio) != blk_integrity_rq(rq))
+ return false;
+
+ return true;
+}
+
+int blk_try_merge(struct request *rq, struct bio *bio)
+{
+ if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_sector)
+ return ELEVATOR_BACK_MERGE;
+ else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_sector)
+ return ELEVATOR_FRONT_MERGE;
+ return ELEVATOR_NO_MERGE;
+}
diff --git a/block/blk.h b/block/blk.h
index df5b59acbdf..d45be871329 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -137,6 +137,8 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
struct request *next);
void blk_recalc_rq_segments(struct request *rq);
void blk_rq_set_mixed_merge(struct request *rq);
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
+int blk_try_merge(struct request *rq, struct bio *bio);
void blk_queue_congestion_threshold(struct request_queue *q);
diff --git a/block/bsg.c b/block/bsg.c
index 4cf703fd98b..ff64ae3bace 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -983,7 +983,8 @@ void bsg_unregister_queue(struct request_queue *q)
mutex_lock(&bsg_mutex);
idr_remove(&bsg_minor_idr, bcd->minor);
- sysfs_remove_link(&q->kobj, "bsg");
+ if (q->kobj.sd)
+ sysfs_remove_link(&q->kobj, "bsg");
device_unregister(bcd->class_dev);
bcd->class_dev = NULL;
kref_put(&bcd->ref, bsg_kref_release_function);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ee55019066a..d0ba5053366 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1699,18 +1699,11 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
/*
* 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.
+ * merge only if rq is queued there.
*/
- 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;
- }
+ 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);
@@ -1794,7 +1787,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfqd->active_queue = NULL;
if (cfqd->active_cic) {
- put_io_context(cfqd->active_cic->icq.ioc, cfqd->queue);
+ put_io_context(cfqd->active_cic->icq.ioc);
cfqd->active_cic = NULL;
}
}
@@ -3117,17 +3110,18 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
*/
static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
+ enum wl_type_t old_type = cfqq_type(cfqd->active_queue);
+
cfq_log_cfqq(cfqd, cfqq, "preempt");
+ cfq_slice_expired(cfqd, 1);
/*
* workload type is changed, don't save slice, otherwise preempt
* doesn't happen
*/
- if (cfqq_type(cfqd->active_queue) != cfqq_type(cfqq))
+ if (old_type != cfqq_type(cfqq))
cfqq->cfqg->saved_workload_slice = 0;
- cfq_slice_expired(cfqd, 1);
-
/*
* Put the new queue at the front of the of the current list,
* so we know that it will be selected next.
diff --git a/block/elevator.c b/block/elevator.c
index 91e18f8af9b..f016855a46b 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -70,39 +70,9 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
/*
* can we safely merge with this request?
*/
-int elv_rq_merge_ok(struct request *rq, struct bio *bio)
+bool elv_rq_merge_ok(struct request *rq, struct bio *bio)
{
- if (!rq_mergeable(rq))
- return 0;
-
- /*
- * Don't merge file system requests and discard requests
- */
- if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
- return 0;
-
- /*
- * Don't merge discard requests and secure discard requests
- */
- if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
- return 0;
-
- /*
- * different data direction or already started, don't merge
- */
- if (bio_data_dir(bio) != rq_data_dir(rq))
- return 0;
-
- /*
- * must be same device and not a special request
- */
- if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
- return 0;
-
- /*
- * only merge integrity protected bio into ditto rq
- */
- if (bio_integrity(bio) != blk_integrity_rq(rq))
+ if (!blk_rq_merge_ok(rq, bio))
return 0;
if (!elv_iosched_allow_merge(rq, bio))
@@ -112,23 +82,6 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
}
EXPORT_SYMBOL(elv_rq_merge_ok);
-int elv_try_merge(struct request *__rq, struct bio *bio)
-{
- int ret = ELEVATOR_NO_MERGE;
-
- /*
- * we can merge and sequence is ok, check if it's possible
- */
- if (elv_rq_merge_ok(__rq, bio)) {
- if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
- ret = ELEVATOR_BACK_MERGE;
- else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
- ret = ELEVATOR_FRONT_MERGE;
- }
-
- return ret;
-}
-
static struct elevator_type *elevator_find(const char *name)
{
struct elevator_type *e;
@@ -478,8 +431,8 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
/*
* First try one-hit cache.
*/
- if (q->last_merge) {
- ret = elv_try_merge(q->last_merge, bio);
+ if (q->last_merge && elv_rq_merge_ok(q->last_merge, bio)) {
+ ret = blk_try_merge(q->last_merge, bio);
if (ret != ELEVATOR_NO_MERGE) {
*req = q->last_merge;
return ret;
diff --git a/block/partitions/ldm.c b/block/partitions/ldm.c
index bd8ae788f68..e507cfbd044 100644
--- a/block/partitions/ldm.c
+++ b/block/partitions/ldm.c
@@ -2,7 +2,7 @@
* ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
*
* Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
- * Copyright (c) 2001-2007 Anton Altaparmakov
+ * Copyright (c) 2001-2012 Anton Altaparmakov
* Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
*
* Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads
@@ -1341,20 +1341,17 @@ found:
ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
return false;
}
-
if (f->map & (1 << rec)) {
ldm_error ("Duplicate VBLK, part %d.", rec);
f->map &= 0x7F; /* Mark the group as broken */
return false;
}
-
f->map |= (1 << rec);
-
+ if (!rec)
+ memcpy(f->data, data, VBLK_SIZE_HEAD);
data += VBLK_SIZE_HEAD;
size -= VBLK_SIZE_HEAD;
-
- memcpy (f->data+rec*(size-VBLK_SIZE_HEAD)+VBLK_SIZE_HEAD, data, size);
-
+ memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
return true;
}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-30 19:33:08 +0000