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path: root/drivers/block/virtio_blk.c
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2008-02-04virtio_blk: implement naming for vda-vdz,vdaa-vdzz,vdaaa-vdzzzChristian Borntraeger
Am Freitag, 1. Februar 2008 schrieb Christian Borntraeger: > Right. I will fix that with an additional patch. This patch goes on top of the minor number patch. Please let me know if you want a merged patch: Currently virtio_blk creates the disk name combinging "vd" with 'a'++. This will give strange names after vdz. I have implemented names up to vdzzz - inspired by the sd.c code. That should be sufficient for now. There is one driver in the kernel (driver/s390/block/dasd_genhd.c) that implements names from dasda-dasdzzzz allowing even more disks. Maybe a janitor can come up with a common implementation usable for all kind of block device drivers. I have tested this patch with 100 disks - seems to work. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio_blk: Dont waste major numbersChristian Borntraeger
Rusty, currently virtio_blk uses one major number per device. While this works quite well on most systems it is wasteful and will exhaust major numbers on larger installations. This patch allocates a major number on init and will use 16 minor numbers for each disk. That will allow ~64k virtio_blk disks. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio_blk: provide getgeoChristian Borntraeger
Rusty, I currently try to make my guest boot from an virtio root device without having an external kernel. Some of the tools that I tried expect HDIO_GETGEO to work. The most interesting value is likely the geo.start value to get the offset of a partition. This value is filled by block/ioctl.c if fops->getgeo is set. This patch also fills in some standard values for heads, sectors and cylinders. Makes sense? Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: reset functionRusty Russell
A reset function solves three problems: 1) It allows us to renegotiate features, eg. if we want to upgrade a guest driver without rebooting the guest. 2) It gives us a clean way of shutting down virtqueues: after a reset, we know that the buffers won't be used by the host, and 3) It helps the guest recover from messed-up drivers. So we remove the ->shutdown hook, and the only way we now remove feature bits is via reset. We leave it to the driver to do the reset before it deletes queues: the balloon driver, for example, needs to chat to the host in its remove function. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: explicit enable_cb/disable_cb rather than callback return.Rusty Russell
It seems that virtio_net wants to disable callbacks (interrupts) before calling netif_rx_schedule(), so we can't use the return value to do so. Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback now returns void, rather than a boolean. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: simplify config mechanism.Rusty Russell
Previously we used a type/len pair within the config space, but this seems overkill. We now simply define a structure which represents the layout in the config space: the config space can now only be extended at the end. The main driver-visible changes: 1) We indicate what fields are present with an explicit feature bit. 2) Virtqueues are explicitly numbered, and not in the config space. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-11-19virtio: fix module/device unloadingRusty Russell
The virtio code never hooked through the ->remove callback. Although noone supports device removal at the moment, this code is already needed for module unloading. This of course also revealed bugs in virtio_blk, virtio_net and lguest unloading paths. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-24SG: audit of drivers that use blk_rq_map_sg()Jens Axboe
They need to properly init the sg table, or blk_rq_map_sg() will complain if CONFIG_DEBUG_SG is set. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-23Block driver using virtio.Rusty Russell
The block driver uses scatter-gather lists with sg[0] being the request information (struct virtio_blk_outhdr) with the type, sector and inbuf id. The next N sg entries are the bio itself, then the last sg is the status byte. Whether the N entries are in or out depends on whether it's a read or a write. We accept the normal (SCSI) ioctls: they get handed through to the other side which can then handle it or reply that it's unsupported. It's not clear that this actually works in general, since I don't know if blk_pc_request() requests have an accurate rq_data_dir(). Although we try to reply -ENOTTY on unsupported commands, ioctl(fd, CDROMEJECT) returns success to userspace. This needs a separate patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <jens.axboe@oracle.com>