From: Yu Kuai yukuai3@huawei.com
[ Upstream commit db59133e927916d8a25ee1fd8264f2808040909d ]
sg_ioctl() support to enable blktrace, which will create debugfs entries "/sys/kernel/debug/block/sgx/", however, there is no guarantee that user will remove these entries through ioctl, and deleting sg device doesn't cleanup these blktrace entries.
This problem can be fixed by cleanup blktrace while releasing request_queue, however, it's not a good idea to do this special handling in common layer just for sg device.
Fix this problem by shutdown bltkrace in sg_device_destroy(), where the device is deleted and all the users close the device, also grab a scsi_device reference from sg_add_device() to prevent scsi_device to be freed before sg_device_destroy();
Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Martin K. Petersen martin.petersen@oracle.com Link: https://lore.kernel.org/r/20230610022003.2557284-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/sg.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 12344be14232b..3d7c27f0bd688 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1496,6 +1496,10 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) int error; unsigned long iflags;
+ error = scsi_device_get(scsidp); + if (error) + return error; + error = -ENOMEM; cdev = cdev_alloc(); if (!cdev) { @@ -1553,6 +1557,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) out: if (cdev) cdev_del(cdev); + scsi_device_put(scsidp); return error; }
@@ -1560,6 +1565,7 @@ static void sg_device_destroy(struct kref *kref) { struct sg_device *sdp = container_of(kref, struct sg_device, d_ref); + struct request_queue *q = sdp->device->request_queue; unsigned long flags;
/* CAUTION! Note that the device can still be found via idr_find() @@ -1567,6 +1573,9 @@ sg_device_destroy(struct kref *kref) * any other cleanup. */
+ blk_trace_remove(q); + scsi_device_put(sdp->device); + write_lock_irqsave(&sg_index_lock, flags); idr_remove(&sg_index_idr, sdp->index); write_unlock_irqrestore(&sg_index_lock, flags);