From: Matias Bjørling Date: Thu, 11 Feb 2016 13:49:13 +0000 (+0100) Subject: null_blk: oops when initializing without lightnvm X-Git-Tag: v4.5-rc5~17^2~11 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a514379b0c77085074abf01c525a850f6d99926e;p=linux.git null_blk: oops when initializing without lightnvm If the LightNVM subsystem is not compiled into the kernel, and the null_blk device driver requests lightnvm to be initialized. The call to nvm_register fails and the null_add_dev function cleans up the initialization. However, at this point the null block device has already been added to the nullb_list and thus a second cleanup will occur when the function has returned, that leads to a double call to blk_cleanup_queue. Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index ae05d31c0559..64a7b5971b57 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -707,9 +707,7 @@ static int null_add_dev(void) queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q); queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, nullb->q); - mutex_lock(&lock); - list_add_tail(&nullb->list, &nullb_list); nullb->index = nullb_indexes++; mutex_unlock(&lock); @@ -743,6 +741,10 @@ static int null_add_dev(void) strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); add_disk(disk); + + mutex_lock(&lock); + list_add_tail(&nullb->list, &nullb_list); + mutex_unlock(&lock); done: return 0;