freeze queue should be used for changing block layer generic setting, such as logical block size, PI, ..., and it is enough to quiesce queue for changing loop specific setting. Remove the queue freeze warning in loop_update_dio(), since it is only needed in loop_set_block_size(), where queue is froze obviously. Fix reported lockdep by syszbot: https://lore.kernel.org/linux-block/67ea99e0.050a0220.3c3d88.0042.GAE@xxxxxxxxxx/ Reported-by: syzbot+9dd7dbb1a4b915dee638@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/block/loop.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 674527d770dc..59886556f55c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -190,8 +190,6 @@ static bool lo_can_use_dio(struct loop_device *lo) static inline void loop_update_dio(struct loop_device *lo) { lockdep_assert_held(&lo->lo_mutex); - WARN_ON_ONCE(lo->lo_state == Lo_bound && - lo->lo_queue->mq_freeze_depth == 0); if ((lo->lo_flags & LO_FLAGS_DIRECT_IO) && !lo_can_use_dio(lo)) lo->lo_flags &= ~LO_FLAGS_DIRECT_IO; @@ -595,7 +593,6 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, { struct file *file = fget(arg); struct file *old_file; - unsigned int memflags; int error; bool partscan; bool is_loop; @@ -640,11 +637,11 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, /* and ... switch */ disk_force_media_change(lo->lo_disk); - memflags = blk_mq_freeze_queue(lo->lo_queue); + blk_mq_quiesce_queue(lo->lo_queue); mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); loop_assign_backing_file(lo, file); loop_update_dio(lo); - blk_mq_unfreeze_queue(lo->lo_queue, memflags); + blk_mq_unquiesce_queue(lo->lo_queue); partscan = lo->lo_flags & LO_FLAGS_PARTSCAN; loop_global_unlock(lo, is_loop); @@ -1270,7 +1267,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) int err; bool partscan = false; bool size_changed = false; - unsigned int memflags; err = mutex_lock_killable(&lo->lo_mutex); if (err) @@ -1287,8 +1283,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) invalidate_bdev(lo->lo_device); } - /* I/O needs to be drained before changing lo_offset or lo_sizelimit */ - memflags = blk_mq_freeze_queue(lo->lo_queue); + /* queue needs to be quiesced before changing lo_offset or lo_sizelimit */ + blk_mq_quiesce_queue(lo->lo_queue); err = loop_set_status_from_info(lo, info); if (err) @@ -1310,7 +1306,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) loop_update_dio(lo); out_unfreeze: - blk_mq_unfreeze_queue(lo->lo_queue, memflags); + blk_mq_unquiesce_queue(lo->lo_queue); if (partscan) clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); out_unlock: -- 2.47.0
