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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-14 17:16:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-14 17:16:45 -0700
commitf1cbd03f5eabb75ea8ace23b47d2209f10871c16 (patch)
tree2ac398bd1a50ce135461fae5b5e91ba05831af84 /block
parentff398c45b03d9d64135d928c0146d8c38a70fd3b (diff)
parentff8c1474cc2f5e11414c71ec4d739c18e6e669c0 (diff)
downloadlinux-linaro-stable-f1cbd03f5eabb75ea8ace23b47d2209f10871c16.tar.gz
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe: "Been sitting on this for a while, but lets get this out the door. This fixes various important bugs for 3.3 final, along with a few more trivial ones. Please pull!" * 'for-linus' of git://git.kernel.dk/linux-block: block: fix ioc leak in put_io_context block, sx8: fix pointer math issue getting fw version Block: use a freezable workqueue for disk-event polling drivers/block/DAC960: fix -Wuninitialized warning drivers/block/DAC960: fix DAC960_V2_IOCTL_Opcode_T -Wenum-compare warning block: fix __blkdev_get and add_disk race condition block: Fix setting bio flags in drivers (sd_dif/floppy) block: Fix NULL pointer dereference in sd_revalidate_disk block: exit_io_context() should call elevator_exit_icq_fn() block: simplify ioc_release_fn() block: replace icq->changed with icq->flags
Diffstat (limited to 'block')
-rw-r--r--block/blk-ioc.c135
-rw-r--r--block/cfq-iosched.c12
-rw-r--r--block/genhd.c42
-rw-r--r--block/partition-generic.c48
4 files changed, 158 insertions, 79 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 8b782a63c297..fb95dd2f889a 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -36,11 +36,23 @@ static void icq_free_icq_rcu(struct rcu_head *head)
kmem_cache_free(icq->__rcu_icq_cache, icq);
}
-/*
- * Exit and free an icq. Called with both ioc and q locked.
- */
+/* Exit an icq. Called with both ioc and q locked. */
static void ioc_exit_icq(struct io_cq *icq)
{
+ struct elevator_type *et = icq->q->elevator->type;
+
+ if (icq->flags & ICQ_EXITED)
+ return;
+
+ if (et->ops.elevator_exit_icq_fn)
+ et->ops.elevator_exit_icq_fn(icq);
+
+ icq->flags |= ICQ_EXITED;
+}
+
+/* Release an icq. Called with both ioc and q locked. */
+static void ioc_destroy_icq(struct io_cq *icq)
+{
struct io_context *ioc = icq->ioc;
struct request_queue *q = icq->q;
struct elevator_type *et = q->elevator->type;
@@ -60,8 +72,7 @@ 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)
- et->ops.elevator_exit_icq_fn(icq);
+ ioc_exit_icq(icq);
/*
* @icq->q might have gone away by the time RCU callback runs
@@ -79,7 +90,6 @@ 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;
/*
@@ -93,44 +103,19 @@ static void ioc_release_fn(struct work_struct *work)
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_irqrestore(&ioc->lock, flags);
- blk_put_queue(last_q);
- } else {
- spin_unlock_irqrestore(&ioc->lock, flags);
- }
-
- last_q = this_q;
- spin_lock_irqsave(this_q->queue_lock, flags);
- spin_lock_nested(&ioc->lock, 1);
- continue;
+ struct request_queue *q = icq->q;
+
+ if (spin_trylock(q->queue_lock)) {
+ ioc_destroy_icq(icq);
+ spin_unlock(q->queue_lock);
+ } else {
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ cpu_relax();
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
}
- ioc_exit_icq(icq);
}
- if (last_q) {
- spin_unlock(last_q->queue_lock);
- spin_unlock_irqrestore(&ioc->lock, flags);
- blk_put_queue(last_q);
- } else {
- spin_unlock_irqrestore(&ioc->lock, flags);
- }
+ spin_unlock_irqrestore(&ioc->lock, flags);
kmem_cache_free(iocontext_cachep, ioc);
}
@@ -145,6 +130,7 @@ static void ioc_release_fn(struct work_struct *work)
void put_io_context(struct io_context *ioc)
{
unsigned long flags;
+ bool free_ioc = false;
if (ioc == NULL)
return;
@@ -159,8 +145,13 @@ void put_io_context(struct io_context *ioc)
spin_lock_irqsave(&ioc->lock, flags);
if (!hlist_empty(&ioc->icq_list))
schedule_work(&ioc->release_work);
+ else
+ free_ioc = true;
spin_unlock_irqrestore(&ioc->lock, flags);
}
+
+ if (free_ioc)
+ kmem_cache_free(iocontext_cachep, ioc);
}
EXPORT_SYMBOL(put_io_context);
@@ -168,13 +159,41 @@ EXPORT_SYMBOL(put_io_context);
void exit_io_context(struct task_struct *task)
{
struct io_context *ioc;
+ struct io_cq *icq;
+ struct hlist_node *n;
+ unsigned long flags;
task_lock(task);
ioc = task->io_context;
task->io_context = NULL;
task_unlock(task);
- atomic_dec(&ioc->nr_tasks);
+ if (!atomic_dec_and_test(&ioc->nr_tasks)) {
+ put_io_context(ioc);
+ return;
+ }
+
+ /*
+ * Need ioc lock to walk icq_list and q lock to exit icq. Perform
+ * reverse double locking. Read comment in ioc_release_fn() for
+ * explanation on the nested locking annotation.
+ */
+retry:
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
+ hlist_for_each_entry(icq, n, &ioc->icq_list, ioc_node) {
+ if (icq->flags & ICQ_EXITED)
+ continue;
+ if (spin_trylock(icq->q->queue_lock)) {
+ ioc_exit_icq(icq);
+ spin_unlock(icq->q->queue_lock);
+ } else {
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ cpu_relax();
+ goto retry;
+ }
+ }
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
put_io_context(ioc);
}
@@ -194,7 +213,7 @@ void ioc_clear_queue(struct request_queue *q)
struct io_context *ioc = icq->ioc;
spin_lock(&ioc->lock);
- ioc_exit_icq(icq);
+ ioc_destroy_icq(icq);
spin_unlock(&ioc->lock);
}
}
@@ -363,13 +382,13 @@ struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask)
return icq;
}
-void ioc_set_changed(struct io_context *ioc, int which)
+void ioc_set_icq_flags(struct io_context *ioc, unsigned int flags)
{
struct io_cq *icq;
struct hlist_node *n;
hlist_for_each_entry(icq, n, &ioc->icq_list, ioc_node)
- set_bit(which, &icq->changed);
+ icq->flags |= flags;
}
/**
@@ -387,7 +406,7 @@ void ioc_ioprio_changed(struct io_context *ioc, int ioprio)
spin_lock_irqsave(&ioc->lock, flags);
ioc->ioprio = ioprio;
- ioc_set_changed(ioc, ICQ_IOPRIO_CHANGED);
+ ioc_set_icq_flags(ioc, ICQ_IOPRIO_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}
@@ -404,11 +423,33 @@ void ioc_cgroup_changed(struct io_context *ioc)
unsigned long flags;
spin_lock_irqsave(&ioc->lock, flags);
- ioc_set_changed(ioc, ICQ_CGROUP_CHANGED);
+ ioc_set_icq_flags(ioc, ICQ_CGROUP_CHANGED);
spin_unlock_irqrestore(&ioc->lock, flags);
}
EXPORT_SYMBOL(ioc_cgroup_changed);
+/**
+ * icq_get_changed - fetch and clear icq changed mask
+ * @icq: icq of interest
+ *
+ * Fetch and clear ICQ_*_CHANGED bits from @icq. Grabs and releases
+ * @icq->ioc->lock.
+ */
+unsigned icq_get_changed(struct io_cq *icq)
+{
+ unsigned int changed = 0;
+ unsigned long flags;
+
+ if (unlikely(icq->flags & ICQ_CHANGED_MASK)) {
+ spin_lock_irqsave(&icq->ioc->lock, flags);
+ changed = icq->flags & ICQ_CHANGED_MASK;
+ icq->flags &= ~ICQ_CHANGED_MASK;
+ spin_unlock_irqrestore(&icq->ioc->lock, flags);
+ }
+ return changed;
+}
+EXPORT_SYMBOL(icq_get_changed);
+
static int __init blk_ioc_init(void)
{
iocontext_cachep = kmem_cache_create("blkdev_ioc",
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index d0ba50533668..457295253566 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3470,20 +3470,20 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
const int rw = rq_data_dir(rq);
const bool is_sync = rq_is_sync(rq);
struct cfq_queue *cfqq;
+ unsigned int changed;
might_sleep_if(gfp_mask & __GFP_WAIT);
spin_lock_irq(q->queue_lock);
/* handle changed notifications */
- if (unlikely(cic->icq.changed)) {
- if (test_and_clear_bit(ICQ_IOPRIO_CHANGED, &cic->icq.changed))
- changed_ioprio(cic);
+ changed = icq_get_changed(&cic->icq);
+ if (unlikely(changed & ICQ_IOPRIO_CHANGED))
+ changed_ioprio(cic);
#ifdef CONFIG_CFQ_GROUP_IOSCHED
- if (test_and_clear_bit(ICQ_CGROUP_CHANGED, &cic->icq.changed))
- changed_cgroup(cic);
+ if (unlikely(changed & ICQ_CGROUP_CHANGED))
+ changed_cgroup(cic);
#endif
- }
new_queue:
cfqq = cic_to_cfqq(cic, is_sync);
diff --git a/block/genhd.c b/block/genhd.c
index 23b4f7063322..df9816ede75b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -35,6 +35,7 @@ static DEFINE_IDR(ext_devt_idr);
static struct device_type disk_type;
+static void disk_alloc_events(struct gendisk *disk);
static void disk_add_events(struct gendisk *disk);
static void disk_del_events(struct gendisk *disk);
static void disk_release_events(struct gendisk *disk);
@@ -601,6 +602,8 @@ void add_disk(struct gendisk *disk)
disk->major = MAJOR(devt);
disk->first_minor = MINOR(devt);
+ disk_alloc_events(disk);
+
/* Register BDI before referencing it from bdev */
bdi = &disk->queue->backing_dev_info;
bdi_register_dev(bdi, disk_devt(disk));
@@ -1475,9 +1478,9 @@ static void __disk_unblock_events(struct gendisk *disk, bool check_now)
intv = disk_events_poll_jiffies(disk);
set_timer_slack(&ev->dwork.timer, intv / 4);
if (check_now)
- queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+ queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
else if (intv)
- queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+ queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv);
out_unlock:
spin_unlock_irqrestore(&ev->lock, flags);
}
@@ -1521,7 +1524,7 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask)
ev->clearing |= mask;
if (!ev->block) {
cancel_delayed_work(&ev->dwork);
- queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+ queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
}
spin_unlock_irq(&ev->lock);
}
@@ -1558,7 +1561,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
/* uncondtionally schedule event check and wait for it to finish */
disk_block_events(disk);
- queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+ queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, 0);
flush_delayed_work(&ev->dwork);
__disk_unblock_events(disk, false);
@@ -1595,7 +1598,7 @@ static void disk_events_workfn(struct work_struct *work)
intv = disk_events_poll_jiffies(disk);
if (!ev->block && intv)
- queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+ queue_delayed_work(system_nrt_freezable_wq, &ev->dwork, intv);
spin_unlock_irq(&ev->lock);
@@ -1733,9 +1736,9 @@ module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
&disk_events_dfl_poll_msecs, 0644);
/*
- * disk_{add|del|release}_events - initialize and destroy disk_events.
+ * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
*/
-static void disk_add_events(struct gendisk *disk)
+static void disk_alloc_events(struct gendisk *disk)
{
struct disk_events *ev;
@@ -1748,16 +1751,6 @@ static void disk_add_events(struct gendisk *disk)
return;
}
- if (sysfs_create_files(&disk_to_dev(disk)->kobj,
- disk_events_attrs) < 0) {
- pr_warn("%s: failed to create sysfs files for events\n",
- disk->disk_name);
- kfree(ev);
- return;
- }
-
- disk->ev = ev;
-
INIT_LIST_HEAD(&ev->node);
ev->disk = disk;
spin_lock_init(&ev->lock);
@@ -1766,8 +1759,21 @@ static void disk_add_events(struct gendisk *disk)
ev->poll_msecs = -1;
INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
+ disk->ev = ev;
+}
+
+static void disk_add_events(struct gendisk *disk)
+{
+ if (!disk->ev)
+ return;
+
+ /* FIXME: error handling */
+ if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
+ pr_warn("%s: failed to create sysfs files for events\n",
+ disk->disk_name);
+
mutex_lock(&disk_events_mutex);
- list_add_tail(&ev->node, &disk_events);
+ list_add_tail(&disk->ev->node, &disk_events);
mutex_unlock(&disk_events_mutex);
/*
diff --git a/block/partition-generic.c b/block/partition-generic.c
index d06ec1c829c2..6df5d6928a44 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -389,17 +389,11 @@ static bool disk_unlock_native_capacity(struct gendisk *disk)
}
}
-int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
+static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
{
- struct parsed_partitions *state = NULL;
struct disk_part_iter piter;
struct hd_struct *part;
- int p, highest, res;
-rescan:
- if (state && !IS_ERR(state)) {
- kfree(state);
- state = NULL;
- }
+ int res;
if (bdev->bd_part_count)
return -EBUSY;
@@ -412,6 +406,24 @@ rescan:
delete_partition(disk, part->partno);
disk_part_iter_exit(&piter);
+ return 0;
+}
+
+int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
+{
+ struct parsed_partitions *state = NULL;
+ struct hd_struct *part;
+ int p, highest, res;
+rescan:
+ if (state && !IS_ERR(state)) {
+ kfree(state);
+ state = NULL;
+ }
+
+ res = drop_partitions(disk, bdev);
+ if (res)
+ return res;
+
if (disk->fops->revalidate_disk)
disk->fops->revalidate_disk(disk);
check_disk_size_change(disk, bdev);
@@ -515,6 +527,26 @@ rescan:
return 0;
}
+int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
+{
+ int res;
+
+ if (!bdev->bd_invalidated)
+ return 0;
+
+ res = drop_partitions(disk, bdev);
+ if (res)
+ return res;
+
+ set_capacity(disk, 0);
+ check_disk_size_change(disk, bdev);
+ bdev->bd_invalidated = 0;
+ /* tell userspace that the media / partition table may have changed */
+ kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+
+ return 0;
+}
+
unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
{
struct address_space *mapping = bdev->bd_inode->i_mapping;