Block device driver: how to terminate the block device if media disappears?

Hi,

I have block driver for a hot-pluggable device PCIe storage device. The driver itself is relatively simple and implements the following block operations:

static struct block_device_operations mydev_ops = {
.owner = THIS_MODULE,
.open = mydev_open,
.release = mydev_release,
.getgeo = mydev_getgeo,
.ioctl = mydev_ioctl
};

and the following PCI driver structure:

static struct pci_driver mydev_driver = {
.name = DRIVER_NAME,
.probe = mydev_pci_init_one,
.remove = mydev_pci_remove_one,
.id_table = mydev_pci_tbl,
};

As well as a request_fn with the following signature:

	static void mydev_submit_req(struct request_queue *q);

Whenever I get IO requests, there is the expected pattern of "open, IO, release", and everything works OK: I can mount the device and access the filesystem.

However, if the device is physically removed during IO, I never seem to get a "release", just "open, IO, hang". I believe (but I don't know), that this is preventing del_gendisk() from completing, thus hanging the cleanup of the driver, which is triggered by mydev_pci_remove_one() upon the removal of the device.

I am ending all requests on the queue with __blk_end_request_all() once an eject happens, but it still doesn't seem to cause a release.

What is the right way to terminate requests and delete the gendisk in the case of physically vanished PCI devices (or even devices in general)? I know I'd end up with a ruined transfer and corrupt data, but that's better than a hung kernel, and if the user is going to rip out a busy disk, those are the breaks.

Thanks in advance for any pointers to a solution, I have looked through drivers/block, read LDD3 and asked at KernelNewbies but have been unable to nail down my error. I'd be happy to provide more code, but I don't want to spam with reams of code if it's not going to be helpful.

John Beard
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