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authorWu Fengguang <fengguang.wu@intel.com>2008-11-25 11:08:39 +0300
committerJens Axboe <jens.axboe@oracle.com>2008-12-29 10:28:43 +0300
commit7c239517d9f18427fc2e7ed259fb3b866595f5af (patch)
treecd2149cc2f2eb0faa83d38fe64e1228f7c703a85
parent42364690992e592c05f85c76fda4055820b48c1b (diff)
downloadlinux-7c239517d9f18427fc2e7ed259fb3b866595f5af.tar.xz
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 Also remove out of date comment for queue_max_sectors_store().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 <wfg@linux.intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--block/blk-sysfs.c7
-rw-r--r--block/compat_ioctl.c2
-rw-r--r--block/ioctl.c2
3 files changed, 1 insertions, 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 */