Re: [PATCH v3] block: genhd: don't call probe function with major_names_lock held
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: 2021-08-17 10:18:24
Also in:
lkml
On 2021/08/17 17:10, Hillf Danton wrote:
See if it is safe to kfree(lo) after removing it from idr, with the deadlock dissolved.
It is not safe to call loop_remove() after idr_remove(). Please see HIDDEN_LOOP_DEVICE magic in "[PATCH] loop: break loop_ctl_mutex into loop_idr_spinlock and loop_removal_mutex".
quoted hunk
--- x/drivers/block/loop.c +++ y/drivers/block/loop.c@@ -2459,7 +2459,9 @@ static int loop_control_remove(int idx) mutex_unlock(&lo->lo_mutex); idr_remove(&loop_index_idr, lo->lo_number); + mutex_unlock(&loop_ctl_mutex); loop_remove(lo); + return 0; out_unlock_ctrl: mutex_unlock(&loop_ctl_mutex); return ret; --
"[PATCH] loop: break loop_ctl_mutex into loop_idr_spinlock and loop_removal_mutex" can be a further improvement after "[PATCH v3] block: genhd: don't call probe function with major_names_lock held". I really would like to apply "[PATCH v3] block: genhd: don't call probe function with major_names_lock held" first.