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Commit 6c7d4945 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

NVMe: Change the definition of nvme_user_io 



The read and write commands don't define a 'result', so there's no need
to copy it back to userspace.

Remove the ability of the ioctl to submit commands to a different
namespace; it's just asking for trouble, and the use case I have in mind
will be addressed througha  different ioctl in the future.  That removes
the need for both the block_shift and nsid arguments.

Check that the opcode is one of 'read' or 'write'.  Future opcodes may
be added in the future, but we will need a different structure definition
for them.

The nblocks field is redefined to be 0-based.  This allows the user to
request the full 65536 blocks.

Don't byteswap the reftag, apptag and appmask.  Martin Petersen tells
me these are calculated in big-endian and are transmitted to the device
in big-endian.

Signed-off-by: default avatarMatthew Wilcox <matthew.r.wilcox@intel.com>
parent 9d4af1b7

drivers/block/nvme.c

+17 −10
Original line number Diff line number Diff line
@@ -1035,29 +1035,37 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) 
	struct nvme_user_io io;

	struct nvme_command c;

	unsigned length;

	u32 result;

	int nents, status;

	struct scatterlist *sg;

	struct nvme_prps *prps;



	if (copy_from_user(&io, uio, sizeof(io)))

		return -EFAULT;

	length = io.nblocks << io.block_shift;

	nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length, &sg);

	length = (io.nblocks + 1) << ns->lba_shift;



	switch (io.opcode) {

	case nvme_cmd_write:

	case nvme_cmd_read:

		nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr,

								length, &sg);

	default:

		return -EFAULT;

	}



	if (nents < 0)

		return nents;



	memset(&c, 0, sizeof(c));

	c.rw.opcode = io.opcode;

	c.rw.flags = io.flags;

	c.rw.nsid = cpu_to_le32(io.nsid);

	c.rw.nsid = cpu_to_le32(ns->ns_id);

	c.rw.slba = cpu_to_le64(io.slba);

	c.rw.length = cpu_to_le16(io.nblocks - 1);

	c.rw.length = cpu_to_le16(io.nblocks);

	c.rw.control = cpu_to_le16(io.control);

	c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);

	c.rw.reftag = cpu_to_le32(io.reftag);	/* XXX: endian? */

	c.rw.apptag = cpu_to_le16(io.apptag);

	c.rw.appmask = cpu_to_le16(io.appmask);

	c.rw.reftag = io.reftag;

	c.rw.apptag = io.apptag;

	c.rw.appmask = io.appmask;

	/* XXX: metadata */

	prps = nvme_setup_prps(dev, &c.common, sg, length);
@@ -1069,11 +1077,10 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) 
	 * additional races since q_lock already protects against other CPUs.

	 */

	put_nvmeq(nvmeq);

	status = nvme_submit_sync_cmd(nvmeq, &c, &result, IO_TIMEOUT);

	status = nvme_submit_sync_cmd(nvmeq, &c, NULL, IO_TIMEOUT);



	nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents);

	nvme_free_prps(dev, prps);

	put_user(result, &uio->result);

	return status;

}

include/linux/nvme.h

+3 −5
Original line number Diff line number Diff line
@@ -373,17 +373,15 @@ struct nvme_user_io { 
	__u8	opcode;

	__u8	flags;

	__u16	control;

	__u32	nsid;

	__u16	nblocks;

	__u16	rsvd;

	__u64	metadata;

	__u64	addr;

	__u64	slba;

	__u16	nblocks;

	__u16	block_shift;

	__u32	dsmgmt;

	__u32	reftag;

	__u16	apptag;

	__u16	appmask;

	__u32	result;

};



struct nvme_dlfw {
@@ -395,7 +393,7 @@ struct nvme_dlfw { 
#define NVME_IOCTL_IDENTIFY_NS	_IOW('N', 0x40, struct nvme_id_ns)

#define NVME_IOCTL_IDENTIFY_CTRL _IOW('N', 0x41, struct nvme_id_ctrl)

#define NVME_IOCTL_GET_RANGE_TYPE _IOW('N', 0x42, struct nvme_lba_range_type)

#define NVME_IOCTL_SUBMIT_IO	_IOWR('N', 0x43, struct nvme_user_io)

#define NVME_IOCTL_SUBMIT_IO	_IOW('N', 0x43, struct nvme_user_io)

#define NVME_IOCTL_DOWNLOAD_FW	_IOW('N', 0x44, struct nvme_dlfw)

#define NVME_IOCTL_ACTIVATE_FW	_IO('N', 0x45)