From 7c239517d9f18427fc2e7ed259fb3b866595f5af Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Tue, 25 Nov 2008 09:08:39 +0100 Subject: [PATCH] block: don't take lock on changing ra_pages There's no need to take queue_lock or kernel_lock when modifying bdi->ra_pages. So remove them. Also remove out of date comment for queue_max_sectors_store(). Signed-off-by: Wu Fengguang Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 7 +------ block/compat_ioctl.c | 2 -- block/ioctl.c | 2 -- 3 files changed, 1 insertion(+), 10 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 21e275d7eed9..a29cb788e408 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -88,9 +88,7 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count) unsigned long ra_kb; ssize_t ret = queue_var_store(&ra_kb, page, count); - spin_lock_irq(q->queue_lock); q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10); - spin_unlock_irq(q->queue_lock); return ret; } @@ -117,10 +115,7 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) return -EINVAL; - /* - * Take the queue lock to update the readahead and max_sectors - * values synchronously: - */ + spin_lock_irq(q->queue_lock); q->max_sectors = max_sectors_kb << 1; spin_unlock_irq(q->queue_lock); diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index 67eb93cff699..f87615dea46b 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -774,9 +774,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) bdi = blk_get_backing_dev_info(bdev); if (bdi == NULL) return -ENOTTY; - lock_kernel(); bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; - unlock_kernel(); return 0; case BLKGETSIZE: size = bdev->bd_inode->i_size; diff --git a/block/ioctl.c b/block/ioctl.c index d03985b04d67..0f22e629b13c 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -323,9 +323,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, bdi = blk_get_backing_dev_info(bdev); if (bdi == NULL) return -ENOTTY; - lock_kernel(); bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; - unlock_kernel(); return 0; case BLKBSZSET: /* set the logical block size */