diff options
| -rw-r--r-- | block/ioctl.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/block/ioctl.c b/block/ioctl.c index 203cb4aeea8b..8061eba42887 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -174,13 +174,18 @@ EXPORT_SYMBOL(__blkdev_reread_part); * This is an exported API for the block driver, and will * try to acquire bd_mutex. If bd_mutex has been held already * in current context, please call __blkdev_reread_part(). + * + * Make sure the held locks in current context aren't required + * in open()/close() handler and I/O path for avoiding ABBA deadlock: + * - bd_mutex is held before calling block driver's open/close + * handler + * - reading partition table may submit I/O to the block device */ int blkdev_reread_part(struct block_device *bdev) { int res; - if (!mutex_trylock(&bdev->bd_mutex)) - return -EBUSY; + mutex_lock(&bdev->bd_mutex); res = __blkdev_reread_part(bdev); mutex_unlock(&bdev->bd_mutex); |