[RFC 5/5] nvme: wire-up support for async-passthru on char-device.
Christoph Hellwig
hch at lst.de
Mon Apr 4 00:20:16 PDT 2022
On Fri, Apr 01, 2022 at 04:33:10PM +0530, Kanchan Joshi wrote:
> Introduce handler for fops->async_cmd(), implementing async passthru
> on char device (/dev/ngX). The handler supports NVME_IOCTL_IO64_CMD.
I really don't like how this still mixes up ioctls and uring cmds,
as mentioned close to half a dozend times we really should not mix
them up. Something like this (untested) patch should help to separate
the much better:
---
>From e145d515929f086b2dadf8816e1397eb287f8ae0 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch at lst.de>
Date: Mon, 4 Apr 2022 07:22:33 +0200
Subject: nvme: split the uring cmd path from the regular ioctl path
io_uring async commands are not ioctls, and we should not reuse
opcodes or otherwise pretend that they are the same.
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
drivers/nvme/host/ioctl.c | 222 ++++++++++++++++++++------------
include/uapi/linux/nvme_ioctl.h | 3 +
2 files changed, 141 insertions(+), 84 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 1d15694d411c0..ea6cfd4321942 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -3,6 +3,7 @@
* Copyright (c) 2011-2014, Intel Corporation.
* Copyright (c) 2017-2021 Christoph Hellwig.
*/
+#include <linux/blk-integrity.h>
#include <linux/ptrace.h> /* for force_successful_syscall_return */
#include <linux/nvme_ioctl.h>
#include "nvme.h"
@@ -19,6 +20,23 @@ static void __user *nvme_to_user_ptr(uintptr_t ptrval)
return (void __user *)ptrval;
}
+static int nvme_ioctl_finish_metadata(struct bio *bio, int ret,
+ void __user *meta_ubuf)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+
+ if (bip) {
+ void *meta = bvec_virt(bip->bip_vec);
+
+ if (!ret && bio_op(bio) == REQ_OP_DRV_IN &&
+ copy_to_user(meta_ubuf, meta, bip->bip_vec->bv_len))
+ ret = -EFAULT;
+ kfree(meta);
+ }
+
+ return ret;
+}
+
/*
* This overlays struct io_uring_cmd pdu.
* Expect build errors if this grows larger than that.
@@ -28,9 +46,7 @@ struct nvme_uring_cmd_pdu {
struct bio *bio;
struct request *req;
};
- void *meta; /* kernel-resident buffer */
void __user *meta_buffer;
- u32 meta_len;
} __packed;
static struct nvme_uring_cmd_pdu *nvme_uring_cmd_pdu(struct io_uring_cmd *ioucmd)
@@ -38,12 +54,11 @@ static struct nvme_uring_cmd_pdu *nvme_uring_cmd_pdu(struct io_uring_cmd *ioucmd
return (struct nvme_uring_cmd_pdu *)&ioucmd->pdu;
}
-static void nvme_pt_task_cb(struct io_uring_cmd *ioucmd)
+static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
{
struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
struct request *req = pdu->req;
struct bio *bio = req->bio;
- bool write = (req_op(req) == REQ_OP_DRV_OUT);
int status;
u64 result;
@@ -56,12 +71,7 @@ static void nvme_pt_task_cb(struct io_uring_cmd *ioucmd)
blk_mq_free_request(req);
blk_rq_unmap_user(bio);
- if (pdu->meta && !status && !write) {
- if (copy_to_user(pdu->meta_buffer, pdu->meta, pdu->meta_len))
- status = -EFAULT;
- }
- kfree(pdu->meta);
-
+ status = nvme_ioctl_finish_metadata(bio, status, pdu->meta_buffer);
result = le64_to_cpu(nvme_req(req)->result.u64);
io_uring_cmd_done(ioucmd, status, result);
}
@@ -77,21 +87,7 @@ static void nvme_end_async_pt(struct request *req, blk_status_t err)
req->bio = bio;
/* this takes care of moving rest of completion-work to task context */
- io_uring_cmd_complete_in_task(ioucmd, nvme_pt_task_cb);
-}
-
-static void nvme_setup_uring_cmd_data(struct request *rq,
- struct io_uring_cmd *ioucmd, void *meta,
- void __user *meta_buffer, u32 meta_len)
-{
- struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
-
- /* to free bio on completion, as req->bio will be null at that time */
- pdu->bio = rq->bio;
- pdu->meta = meta;
- pdu->meta_buffer = meta_buffer;
- pdu->meta_len = meta_len;
- rq->end_io_data = ioucmd;
+ io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
}
static void *nvme_add_user_metadata(struct bio *bio, void __user *ubuf,
@@ -128,11 +124,10 @@ static void *nvme_add_user_metadata(struct bio *bio, void __user *ubuf,
return ERR_PTR(ret);
}
-static int nvme_submit_user_cmd(struct request_queue *q,
+static struct request *nvme_alloc_user_request(struct request_queue *q,
struct nvme_command *cmd, void __user *ubuffer,
unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
- u32 meta_seed, u64 *result, unsigned timeout,
- struct io_uring_cmd *ioucmd)
+ u32 meta_seed, unsigned timeout)
{
bool write = nvme_is_write(cmd);
struct nvme_ns *ns = q->queuedata;
@@ -144,7 +139,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
req = nvme_alloc_request(q, cmd, 0);
if (IS_ERR(req))
- return PTR_ERR(req);
+ return req;
if (timeout)
req->timeout = timeout;
@@ -169,28 +164,47 @@ static int nvme_submit_user_cmd(struct request_queue *q,
}
}
- if (ioucmd) { /* async dispatch */
- nvme_setup_uring_cmd_data(req, ioucmd, meta, meta_buffer,
- meta_len);
- blk_execute_rq_nowait(req, 0, nvme_end_async_pt);
- return -EIOCBQUEUED;
- }
+ return req;
+
+out_unmap:
+ if (bio)
+ blk_rq_unmap_user(bio);
+out:
+ blk_mq_free_request(req);
+ return ERR_PTR(ret);
+}
+
+static int nvme_execute_user_rq(struct request *req,
+ void __user *meta_buffer, u64 *result)
+{
+ struct bio *bio = req->bio;
+ int ret;
+
ret = nvme_execute_passthru_rq(req);
+
if (result)
*result = le64_to_cpu(nvme_req(req)->result.u64);
- if (meta && !ret && !write) {
- if (copy_to_user(meta_buffer, meta, meta_len))
- ret = -EFAULT;
- }
- kfree(meta);
- out_unmap:
+ ret = nvme_ioctl_finish_metadata(bio, ret, meta_buffer);
+
if (bio)
blk_rq_unmap_user(bio);
- out:
blk_mq_free_request(req);
return ret;
}
+static int nvme_submit_user_cmd(struct request_queue *q,
+ struct nvme_command *cmd, void __user *ubuffer,
+ unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
+ u32 meta_seed, u64 *result, unsigned timeout)
+{
+ struct request *req;
+
+ req = nvme_alloc_user_request(q, cmd, ubuffer, bufflen, meta_buffer,
+ meta_len, meta_seed, timeout);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+ return nvme_execute_user_rq(req, meta_buffer, result);
+}
static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
{
@@ -252,7 +266,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
return nvme_submit_user_cmd(ns->queue, &c,
nvme_to_user_ptr(io.addr), length,
- metadata, meta_len, lower_32_bits(io.slba), NULL, 0, NULL);
+ metadata, meta_len, lower_32_bits(io.slba), NULL, 0);
}
static bool nvme_validate_passthru_nsid(struct nvme_ctrl *ctrl,
@@ -306,7 +320,7 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
nvme_to_user_ptr(cmd.addr), cmd.data_len,
nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
- 0, &result, timeout, NULL);
+ 0, &result, timeout);
if (status >= 0) {
if (put_user(result, &ucmd->result))
@@ -317,57 +331,98 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
}
static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
- struct nvme_passthru_cmd64 __user *ucmd,
- struct io_uring_cmd *ioucmd)
+ struct nvme_passthru_cmd64 __user *ucmd)
{
- struct nvme_passthru_cmd64 cmd, *cptr;
+ struct nvme_passthru_cmd64 cmd;
struct nvme_command c;
unsigned timeout = 0;
int status;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- if (!ioucmd) {
- if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
- return -EFAULT;
- cptr = &cmd;
- } else {
- cptr = (struct nvme_passthru_cmd64 *)ioucmd->cmd;
- }
- if (cptr->flags)
+ if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
+ return -EFAULT;
+ if (cmd.flags)
return -EINVAL;
- if (!nvme_validate_passthru_nsid(ctrl, ns, cptr->nsid))
+ if (!nvme_validate_passthru_nsid(ctrl, ns, cmd.nsid))
return -EINVAL;
memset(&c, 0, sizeof(c));
- c.common.opcode = cptr->opcode;
- c.common.flags = cptr->flags;
- c.common.nsid = cpu_to_le32(cptr->nsid);
- c.common.cdw2[0] = cpu_to_le32(cptr->cdw2);
- c.common.cdw2[1] = cpu_to_le32(cptr->cdw3);
- c.common.cdw10 = cpu_to_le32(cptr->cdw10);
- c.common.cdw11 = cpu_to_le32(cptr->cdw11);
- c.common.cdw12 = cpu_to_le32(cptr->cdw12);
- c.common.cdw13 = cpu_to_le32(cptr->cdw13);
- c.common.cdw14 = cpu_to_le32(cptr->cdw14);
- c.common.cdw15 = cpu_to_le32(cptr->cdw15);
-
- if (cptr->timeout_ms)
- timeout = msecs_to_jiffies(cptr->timeout_ms);
+ c.common.opcode = cmd.opcode;
+ c.common.flags = cmd.flags;
+ c.common.nsid = cpu_to_le32(cmd.nsid);
+ c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
+ c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
+ c.common.cdw10 = cpu_to_le32(cmd.cdw10);
+ c.common.cdw11 = cpu_to_le32(cmd.cdw11);
+ c.common.cdw12 = cpu_to_le32(cmd.cdw12);
+ c.common.cdw13 = cpu_to_le32(cmd.cdw13);
+ c.common.cdw14 = cpu_to_le32(cmd.cdw14);
+ c.common.cdw15 = cpu_to_le32(cmd.cdw15);
+
+ if (cmd.timeout_ms)
+ timeout = msecs_to_jiffies(cmd.timeout_ms);
status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
- nvme_to_user_ptr(cptr->addr), cptr->data_len,
- nvme_to_user_ptr(cptr->metadata), cptr->metadata_len,
- 0, &cptr->result, timeout, ioucmd);
+ nvme_to_user_ptr(cmd.addr), cmd.data_len,
+ nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
+ 0, &cmd.result, timeout);
- if (!ioucmd && status >= 0) {
- if (put_user(cptr->result, &ucmd->result))
+ if (status >= 0) {
+ if (put_user(cmd.result, &ucmd->result))
return -EFAULT;
}
return status;
}
+static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+ struct io_uring_cmd *ioucmd)
+{
+ struct nvme_passthru_cmd64 *cmd =
+ (struct nvme_passthru_cmd64 *)ioucmd->cmd;
+ struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
+ struct request_queue *q = ns ? ns->queue : ctrl->admin_q;
+ struct nvme_command c;
+ struct request *req;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (cmd->flags || cmd->result)
+ return -EINVAL;
+ if (!nvme_validate_passthru_nsid(ctrl, ns, cmd->nsid))
+ return -EINVAL;
+
+ memset(&c, 0, sizeof(c));
+ c.common.opcode = cmd->opcode;
+ c.common.flags = cmd->flags;
+ c.common.nsid = cpu_to_le32(cmd->nsid);
+ c.common.cdw2[0] = cpu_to_le32(cmd->cdw2);
+ c.common.cdw2[1] = cpu_to_le32(cmd->cdw3);
+ c.common.cdw10 = cpu_to_le32(cmd->cdw10);
+ c.common.cdw11 = cpu_to_le32(cmd->cdw11);
+ c.common.cdw12 = cpu_to_le32(cmd->cdw12);
+ c.common.cdw13 = cpu_to_le32(cmd->cdw13);
+ c.common.cdw14 = cpu_to_le32(cmd->cdw14);
+ c.common.cdw15 = cpu_to_le32(cmd->cdw15);
+
+ req = nvme_alloc_user_request(q, &c, nvme_to_user_ptr(cmd->addr),
+ cmd->data_len, nvme_to_user_ptr(cmd->metadata),
+ cmd->metadata_len, 0, cmd->timeout_ms ?
+ msecs_to_jiffies(cmd->timeout_ms) : 0);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ /* to free bio on completion, as req->bio will be null at that time */
+ pdu->bio = req->bio;
+ pdu->meta_buffer = nvme_to_user_ptr(cmd->metadata);
+ req->end_io_data = ioucmd;
+
+ blk_execute_rq_nowait(req, 0, nvme_end_async_pt);
+ return -EIOCBQUEUED;
+}
+
static bool is_ctrl_ioctl(unsigned int cmd)
{
if (cmd == NVME_IOCTL_ADMIN_CMD || cmd == NVME_IOCTL_ADMIN64_CMD)
@@ -384,7 +439,7 @@ static int nvme_ctrl_ioctl(struct nvme_ctrl *ctrl, unsigned int cmd,
case NVME_IOCTL_ADMIN_CMD:
return nvme_user_cmd(ctrl, NULL, argp);
case NVME_IOCTL_ADMIN64_CMD:
- return nvme_user_cmd64(ctrl, NULL, argp, NULL);
+ return nvme_user_cmd64(ctrl, NULL, argp);
default:
return sed_ioctl(ctrl->opal_dev, cmd, argp);
}
@@ -428,7 +483,7 @@ static int nvme_ns_ioctl(struct nvme_ns *ns, unsigned int cmd,
case NVME_IOCTL_SUBMIT_IO:
return nvme_submit_io(ns, argp);
case NVME_IOCTL_IO64_CMD:
- return nvme_user_cmd64(ns->ctrl, ns, argp, NULL);
+ return nvme_user_cmd64(ns->ctrl, ns, argp);
default:
return -ENOTTY;
}
@@ -457,13 +512,13 @@ long nvme_ns_chr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return __nvme_ioctl(ns, cmd, (void __user *)arg);
}
-static int nvme_ns_async_ioctl(struct nvme_ns *ns, struct io_uring_cmd *ioucmd)
+static int nvme_ns_async_cmd(struct nvme_ns *ns, struct io_uring_cmd *ioucmd)
{
int ret;
switch (ioucmd->cmd_op) {
- case NVME_IOCTL_IO64_CMD:
- ret = nvme_user_cmd64(ns->ctrl, ns, NULL, ioucmd);
+ case NVME_URING_CMD_IO:
+ ret = nvme_uring_cmd_io(ns->ctrl, ns, ioucmd);
break;
default:
ret = -ENOTTY;
@@ -476,10 +531,9 @@ int nvme_ns_chr_async_cmd(struct io_uring_cmd *ioucmd)
{
struct nvme_ns *ns = container_of(file_inode(ioucmd->file)->i_cdev,
struct nvme_ns, cdev);
- return nvme_ns_async_ioctl(ns, ioucmd);
+ return nvme_ns_async_cmd(ns, ioucmd);
}
-
#ifdef CONFIG_NVME_MULTIPATH
static int nvme_ns_head_ctrl_ioctl(struct nvme_ns *ns, unsigned int cmd,
void __user *argp, struct nvme_ns_head *head, int srcu_idx)
@@ -556,7 +610,7 @@ int nvme_ns_head_chr_async_cmd(struct io_uring_cmd *ioucmd)
int ret = -EWOULDBLOCK;
if (ns)
- ret = nvme_ns_async_ioctl(ns, ioucmd);
+ ret = nvme_ns_async_cmd(ns, ioucmd);
srcu_read_unlock(&head->srcu, srcu_idx);
return ret;
}
@@ -605,7 +659,7 @@ long nvme_dev_ioctl(struct file *file, unsigned int cmd,
case NVME_IOCTL_ADMIN_CMD:
return nvme_user_cmd(ctrl, NULL, argp);
case NVME_IOCTL_ADMIN64_CMD:
- return nvme_user_cmd64(ctrl, NULL, argp, NULL);
+ return nvme_user_cmd64(ctrl, NULL, argp);
case NVME_IOCTL_IO_CMD:
return nvme_dev_user_cmd(ctrl, argp);
case NVME_IOCTL_RESET:
diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index d99b5a7726980..39c9d3ecfef88 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -79,4 +79,7 @@ struct nvme_passthru_cmd64 {
#define NVME_IOCTL_ADMIN64_CMD _IOWR('N', 0x47, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD _IOWR('N', 0x48, struct nvme_passthru_cmd64)
+/* io_uring async commands: */
+#define NVME_URING_CMD_IO _IOWR('N', 0x80, struct nvme_passthru_cmd64)
+
#endif /* _UAPI_LINUX_NVME_IOCTL_H */
--
2.30.2
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