From: Ming Lei ming.lei@redhat.com
hulk inclusion category: bugfix bugzilla: 182378 https://gitee.com/openeuler/kernel/issues/I4DDEL
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For fixing queue quiesce race between driver and block layer(elevator switch, update nr_requests, ...), we need to support concurrent quiesce and unquiesce, which requires the two to be balanced.
blk_mq_quiesce_queue() calls blk_mq_quiesce_queue_nowait() for updating quiesce depth and marking the flag, then scsi_internal_device_block() calls blk_mq_quiesce_queue_nowait() two times actually.
Fix the double quiesce and keep quiesce and unquiesce balanced.
Reported-by: Yi Zhang yi.zhang@redhat.com Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce") Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/scsi/scsi_lib.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index b26c922bd65d..2561d48dfade 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2618,6 +2618,14 @@ scsi_target_resume(struct scsi_target *starget) } EXPORT_SYMBOL(scsi_target_resume);
+static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) +{ + if (scsi_device_set_state(sdev, SDEV_BLOCK)) + return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); + + return 0; +} + /** * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state * @sdev: device to block @@ -2634,24 +2642,16 @@ EXPORT_SYMBOL(scsi_target_resume); */ int scsi_internal_device_block_nowait(struct scsi_device *sdev) { - struct request_queue *q = sdev->request_queue; - int err = 0; - - err = scsi_device_set_state(sdev, SDEV_BLOCK); - if (err) { - err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); - - if (err) - return err; - } + int ret = __scsi_internal_device_block_nowait(sdev);
/* * The device has transitioned to SDEV_BLOCK. Stop the * block layer from calling the midlayer with this device's * request queue. */ - blk_mq_quiesce_queue_nowait(q); - return 0; + if (!ret) + blk_mq_quiesce_queue_nowait(sdev->request_queue); + return ret; } EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
@@ -2672,13 +2672,12 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); */ static int scsi_internal_device_block(struct scsi_device *sdev) { - struct request_queue *q = sdev->request_queue; int err;
mutex_lock(&sdev->state_mutex); - err = scsi_internal_device_block_nowait(sdev); + err = __scsi_internal_device_block_nowait(sdev); if (err == 0) - blk_mq_quiesce_queue(q); + blk_mq_quiesce_queue(sdev->request_queue); mutex_unlock(&sdev->state_mutex);
return err;