From 34ae2e47d97216d8c66a1c5dff5b530c29b746b8 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sat, 21 Jan 2012 00:15:26 +0900 Subject: xen-blkfront: use bitmap_set() and bitmap_clear() Use bitmap_set and bitmap_clear rather than modifying individual bits in a memory region. Signed-off-by: Akinobu Mita Cc: Jeremy Fitzhardinge Cc: Konrad Rzeszutek Wilk Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkfront.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'drivers/block/xen-blkfront.c') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2f22874c0a37..619868d91ca8 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -177,8 +178,7 @@ static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) spin_lock(&minor_lock); if (find_next_bit(minors, end, minor) >= end) { - for (; minor < end; ++minor) - __set_bit(minor, minors); + bitmap_set(minors, minor, nr); rc = 0; } else rc = -EBUSY; @@ -193,8 +193,7 @@ static void xlbd_release_minors(unsigned int minor, unsigned int nr) BUG_ON(end > nr_minors); spin_lock(&minor_lock); - for (; minor < end; ++minor) - __clear_bit(minor, minors); + bitmap_clear(minors, minor, nr); spin_unlock(&minor_lock); } -- cgit v1.2.3 From dad5cf659b202b5070c8616b5c515f6ca4db0c42 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Thu, 16 Feb 2012 13:16:25 +0100 Subject: xen/blkfront: don't put bdev right after getting it We should hang onto bdev until we're done with it. Signed-off-by: Andrew Jones [v1: Fixed up git commit description] Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/block/xen-blkfront.c') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 619868d91ca8..537cb722a211 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1409,7 +1409,6 @@ static int blkif_release(struct gendisk *disk, fmode_t mode) mutex_lock(&blkfront_mutex); bdev = bdget_disk(disk, 0); - bdput(bdev); if (bdev->bd_openers) goto out; @@ -1440,6 +1439,7 @@ static int blkif_release(struct gendisk *disk, fmode_t mode) } out: + bdput(bdev); mutex_unlock(&blkfront_mutex); return 0; } -- cgit v1.2.3 From 3467811e26660eb46bc655234573d22d6876d5f9 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Fri, 17 Feb 2012 12:04:44 -0800 Subject: xen-blkfront: make blkif_io_lock spinlock per-device This patch moves the global blkif_io_lock to the per-device structure. The spinlock seems to exists for two reasons: to disable IRQs when in the interrupt handlers for blkfront, and to protect the blkfront VBDs when a detachment is requested. Having a global blkif_io_lock doesn't make sense given the use case, and it drastically hinders performance due to contention. All VBDs with pending IOs have to take the lock in order to get work done, which serializes everything pretty badly. Signed-off-by: Steven Noonan Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkfront.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'drivers/block/xen-blkfront.c') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 537cb722a211..5d9c559f1877 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -82,6 +82,7 @@ static const struct block_device_operations xlvbd_block_fops; */ struct blkfront_info { + spinlock_t io_lock; struct mutex mutex; struct xenbus_device *xbdev; struct gendisk *gd; @@ -106,8 +107,6 @@ struct blkfront_info int is_ready; }; -static DEFINE_SPINLOCK(blkif_io_lock); - static unsigned int nr_minors; static unsigned long *minors; static DEFINE_SPINLOCK(minor_lock); @@ -418,7 +417,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size) struct request_queue *rq; struct blkfront_info *info = gd->private_data; - rq = blk_init_queue(do_blkif_request, &blkif_io_lock); + rq = blk_init_queue(do_blkif_request, &info->io_lock); if (rq == NULL) return -1; @@ -635,14 +634,14 @@ static void xlvbd_release_gendisk(struct blkfront_info *info) if (info->rq == NULL) return; - spin_lock_irqsave(&blkif_io_lock, flags); + spin_lock_irqsave(&info->io_lock, flags); /* No more blkif_request(). */ blk_stop_queue(info->rq); /* No more gnttab callback work. */ gnttab_cancel_free_callback(&info->callback); - spin_unlock_irqrestore(&blkif_io_lock, flags); + spin_unlock_irqrestore(&info->io_lock, flags); /* Flush gnttab callback work. Must be done with no locks held. */ flush_work_sync(&info->work); @@ -674,16 +673,16 @@ static void blkif_restart_queue(struct work_struct *work) { struct blkfront_info *info = container_of(work, struct blkfront_info, work); - spin_lock_irq(&blkif_io_lock); + spin_lock_irq(&info->io_lock); if (info->connected == BLKIF_STATE_CONNECTED) kick_pending_request_queues(info); - spin_unlock_irq(&blkif_io_lock); + spin_unlock_irq(&info->io_lock); } static void blkif_free(struct blkfront_info *info, int suspend) { /* Prevent new requests being issued until we fix things up. */ - spin_lock_irq(&blkif_io_lock); + spin_lock_irq(&info->io_lock); info->connected = suspend ? BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; /* No more blkif_request(). */ @@ -691,7 +690,7 @@ static void blkif_free(struct blkfront_info *info, int suspend) blk_stop_queue(info->rq); /* No more gnttab callback work. */ gnttab_cancel_free_callback(&info->callback); - spin_unlock_irq(&blkif_io_lock); + spin_unlock_irq(&info->io_lock); /* Flush gnttab callback work. Must be done with no locks held. */ flush_work_sync(&info->work); @@ -727,10 +726,10 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) struct blkfront_info *info = (struct blkfront_info *)dev_id; int error; - spin_lock_irqsave(&blkif_io_lock, flags); + spin_lock_irqsave(&info->io_lock, flags); if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { - spin_unlock_irqrestore(&blkif_io_lock, flags); + spin_unlock_irqrestore(&info->io_lock, flags); return IRQ_HANDLED; } @@ -815,7 +814,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) kick_pending_request_queues(info); - spin_unlock_irqrestore(&blkif_io_lock, flags); + spin_unlock_irqrestore(&info->io_lock, flags); return IRQ_HANDLED; } @@ -990,6 +989,7 @@ static int blkfront_probe(struct xenbus_device *dev, } mutex_init(&info->mutex); + spin_lock_init(&info->io_lock); info->xbdev = dev; info->vdevice = vdevice; info->connected = BLKIF_STATE_DISCONNECTED; @@ -1067,7 +1067,7 @@ static int blkif_recover(struct blkfront_info *info) xenbus_switch_state(info->xbdev, XenbusStateConnected); - spin_lock_irq(&blkif_io_lock); + spin_lock_irq(&info->io_lock); /* Now safe for us to use the shared ring */ info->connected = BLKIF_STATE_CONNECTED; @@ -1078,7 +1078,7 @@ static int blkif_recover(struct blkfront_info *info) /* Kick any other new requests queued since we resumed */ kick_pending_request_queues(info); - spin_unlock_irq(&blkif_io_lock); + spin_unlock_irq(&info->io_lock); return 0; } @@ -1276,10 +1276,10 @@ static void blkfront_connect(struct blkfront_info *info) xenbus_switch_state(info->xbdev, XenbusStateConnected); /* Kick pending requests. */ - spin_lock_irq(&blkif_io_lock); + spin_lock_irq(&info->io_lock); info->connected = BLKIF_STATE_CONNECTED; kick_pending_request_queues(info); - spin_unlock_irq(&blkif_io_lock); + spin_unlock_irq(&info->io_lock); add_disk(info->gd); -- cgit v1.2.3