From d4dc210f69bcb0b4bef5a83b1c323817be89bad1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 21 Apr 2011 20:54:46 +0200 Subject: block: don't block events on excl write for non-optical devices Disk event code automatically blocks events on excl write. This is primarily to avoid issuing polling commands while burning is in progress. This behavior doesn't fit other types of devices with removeable media where polling commands don't have adverse side effects and door locking usually doesn't exist. This patch introduces new genhd flag which controls the auto-blocking behavior and uses it to enable auto-blocking only on optical devices. Note for stable: 2.6.38 and later only Cc: stable@kernel.org Signed-off-by: Tejun Heo Reported-by: Kay Sievers Signed-off-by: Jens Axboe --- fs/block_dev.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'fs/block_dev.c') diff --git a/fs/block_dev.c b/fs/block_dev.c index 257b00e98428..d7c2e0fddc6f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1237,6 +1237,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) res = __blkdev_get(bdev, mode, 0); if (whole) { + struct gendisk *disk = whole->bd_disk; + /* finish claiming */ mutex_lock(&bdev->bd_mutex); spin_lock(&bdev_lock); @@ -1263,15 +1265,16 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) spin_unlock(&bdev_lock); /* - * Block event polling for write claims. Any write - * holder makes the write_holder state stick until all - * are released. This is good enough and tracking - * individual writeable reference is too fragile given - * the way @mode is used in blkdev_get/put(). + * Block event polling for write claims if requested. Any + * write holder makes the write_holder state stick until + * all are released. This is good enough and tracking + * individual writeable reference is too fragile given the + * way @mode is used in blkdev_get/put(). */ - if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) { + if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) && + !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) { bdev->bd_write_holder = true; - disk_block_events(bdev->bd_disk); + disk_block_events(disk); } mutex_unlock(&bdev->bd_mutex); -- cgit v1.2.3