From 74e6464a987b2572771ac19163e961777fd0252e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 1 Jun 2023 11:44:46 +0200 Subject: block: turn bdev_lock into a mutex There is no reason for this lock to spin, and being able to sleep under it will come in handy soon. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Acked-by: Christian Brauner Acked-by: Dave Chinner Reviewed-by: Dave Chinner Link: https://lore.kernel.org/r/20230601094459.1350643-4-hch@lst.de Signed-off-by: Jens Axboe --- block/bdev.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) (limited to 'block/bdev.c') diff --git a/block/bdev.c b/block/bdev.c index 080b5c83bfbc..f5ffcac762e0 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -308,7 +308,7 @@ EXPORT_SYMBOL(thaw_bdev); * pseudo-fs */ -static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); +static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); static struct kmem_cache * bdev_cachep __read_mostly; static struct inode *bdev_alloc_inode(struct super_block *sb) @@ -467,9 +467,6 @@ long nr_blockdev_pages(void) * * Test whether @bdev can be claimed by @holder. * - * CONTEXT: - * spin_lock(&bdev_lock). - * * RETURNS: * %true if @bdev can be claimed, %false otherwise. */ @@ -477,6 +474,8 @@ static bool bd_may_claim(struct block_device *bdev, void *holder) { struct block_device *whole = bdev_whole(bdev); + lockdep_assert_held(&bdev_lock); + if (bdev->bd_holder) { /* * The same holder can always re-claim. @@ -515,10 +514,10 @@ int bd_prepare_to_claim(struct block_device *bdev, void *holder) if (WARN_ON_ONCE(!holder)) return -EINVAL; retry: - spin_lock(&bdev_lock); + mutex_lock(&bdev_lock); /* if someone else claimed, fail */ if (!bd_may_claim(bdev, holder)) { - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); return -EBUSY; } @@ -528,7 +527,7 @@ retry: DEFINE_WAIT(wait); prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); schedule(); finish_wait(wq, &wait); goto retry; @@ -536,7 +535,7 @@ retry: /* yay, all mine */ whole->bd_claiming = holder; - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); return 0; } EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ @@ -562,7 +561,7 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder) { struct block_device *whole = bdev_whole(bdev); - spin_lock(&bdev_lock); + mutex_lock(&bdev_lock); BUG_ON(!bd_may_claim(bdev, holder)); /* * Note that for a whole device bd_holders will be incremented twice, @@ -573,7 +572,7 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder) bdev->bd_holders++; bdev->bd_holder = holder; bd_clear_claiming(whole, holder); - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); } /** @@ -587,9 +586,9 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder) */ void bd_abort_claiming(struct block_device *bdev, void *holder) { - spin_lock(&bdev_lock); + mutex_lock(&bdev_lock); bd_clear_claiming(bdev_whole(bdev), holder); - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); } EXPORT_SYMBOL(bd_abort_claiming); @@ -602,7 +601,7 @@ static void bd_end_claim(struct block_device *bdev) * Release a claim on the device. The holder fields are protected with * bdev_lock. open_mutex is used to synchronize disk_holder unlinking. */ - spin_lock(&bdev_lock); + mutex_lock(&bdev_lock); WARN_ON_ONCE(--bdev->bd_holders < 0); WARN_ON_ONCE(--whole->bd_holders < 0); if (!bdev->bd_holders) { @@ -612,7 +611,7 @@ static void bd_end_claim(struct block_device *bdev) } if (!whole->bd_holders) whole->bd_holder = NULL; - spin_unlock(&bdev_lock); + mutex_unlock(&bdev_lock); /* * If this was the last claim, remove holder link and unblock evpoll if -- cgit