From 6936217cc7e58573026bdba25b1bfb778e8f2267 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 9 Mar 2011 19:54:27 +0100 Subject: [PATCH] block: Don't check events on close unless it was blocked The block event mechanism currently always checks events when the device is being closed regardless of the open mode. The intention was to allow detection of EJECT_REQUEST when a device is closed whether disk event polling is enabled or not. This is unnecessary as, for devices of interest, events are checked from either userland or kernel and in the former case ->check_events() is performed on open of each poll attempt anyway. Furthermore, this unconditional event check on close makes the code susceptible to event loop if the block driver doesn't clear reported events correctly - an event triggers userland to open and close the device which in turn causes another event, rinse and repeat. Check events on close only if it was blocked by excl write open. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Kay Sievers --- fs/block_dev.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index fffdf86c1757..7dd2c658d429 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1448,13 +1448,11 @@ int blkdev_put(struct block_device *bdev, fmode_t mode) disk_unblock_events(bdev->bd_disk); disk_check_events(bdev->bd_disk); bdev->bd_write_holder = false; - } else - disk_check_events(bdev->bd_disk); + } } mutex_unlock(&bdev->bd_mutex); - } else - disk_check_events(bdev->bd_disk); + } return __blkdev_put(bdev, mode, 0); } -- 2.20.1