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io_uring/kbuf: unify legacy buf provision and removal 

Combine IORING_OP_PROVIDE_BUFFERS and IORING_OP_REMOVE_BUFFERS
->issue(), so that we can deduplicate ring locking and list lookups.
This way we further reduce code for legacy provided buffers. Locking is
also separated from buffer related handling, which makes it a bit
simpler with label jumps.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f61af131622ad4337c2fb9f7c453d5b0102c7b90.1747150490.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
pull/1250/head
Pavel Begunkov 2025-05-13 18:26:51 +01:00 committed by Jens Axboe
parent c724e80123
commit 2b61bb1d9a
3 changed files with 34 additions and 53 deletions
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79
io_uring/kbuf.c
View File

@ -450,30 +450,6 @@ int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return 0;
}
int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf);
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer_list *bl;
int ret = 0;
io_ring_submit_lock(ctx, issue_flags);
ret = -ENOENT;
bl = io_buffer_get_list(ctx, p->bgid);
if (bl) {
ret = -EINVAL;
/* can't use provide/remove buffers command on mapped buffers */
if (!(bl->flags & IOBL_BUF_RING))
ret = io_remove_buffers_legacy(ctx, bl, p->nbufs);
}
io_ring_submit_unlock(ctx, issue_flags);
if (ret < 0)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
unsigned long size, tmp_check;
@ -535,37 +511,44 @@ static int io_add_buffers(struct io_ring_ctx *ctx, struct io_provide_buf *pbuf,
return i ? 0 : -ENOMEM;
}
int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags)
static int __io_manage_buffers_legacy(struct io_kiocb *req,
struct io_buffer_list *bl)
{
struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf);
int ret;
if (!bl) {
if (req->opcode != IORING_OP_PROVIDE_BUFFERS)
return -ENOENT;
bl = kzalloc(sizeof(*bl), GFP_KERNEL_ACCOUNT);
if (!bl)
return -ENOMEM;
INIT_LIST_HEAD(&bl->buf_list);
ret = io_buffer_add_list(req->ctx, bl, p->bgid);
if (ret) {
kfree(bl);
return ret;
}
}
/* can't use provide/remove buffers command on mapped buffers */
if (bl->flags & IOBL_BUF_RING)
return -EINVAL;
if (req->opcode == IORING_OP_PROVIDE_BUFFERS)
return io_add_buffers(req->ctx, p, bl);
return io_remove_buffers_legacy(req->ctx, bl, p->nbufs);
}
int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf);
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer_list *bl;
int ret = 0;
int ret;
io_ring_submit_lock(ctx, issue_flags);
bl = io_buffer_get_list(ctx, p->bgid);
if (unlikely(!bl)) {
bl = kzalloc(sizeof(*bl), GFP_KERNEL_ACCOUNT);
if (!bl) {
ret = -ENOMEM;
goto err;
}
INIT_LIST_HEAD(&bl->buf_list);
ret = io_buffer_add_list(ctx, bl, p->bgid);
if (ret) {
kfree(bl);
goto err;
}
}
/* can't add buffers via this command for a mapped buffer ring */
if (bl->flags & IOBL_BUF_RING) {
ret = -EINVAL;
goto err;
}
ret = io_add_buffers(ctx, p, bl);
err:
ret = __io_manage_buffers_legacy(req, bl);
io_ring_submit_unlock(ctx, issue_flags);
if (ret < 0)

4
io_uring/kbuf.h
View File

@ -66,10 +66,8 @@ int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg);
void io_destroy_buffers(struct io_ring_ctx *ctx);
int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags);
int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags);
int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags);
int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);

4
io_uring/opdef.c
View File

@ -333,13 +333,13 @@ const struct io_issue_def io_issue_defs[] = {
.audit_skip = 1,
.iopoll = 1,
.prep = io_provide_buffers_prep,
.issue = io_provide_buffers,
.issue = io_manage_buffers_legacy,
},
[IORING_OP_REMOVE_BUFFERS] = {
.audit_skip = 1,
.iopoll = 1,
.prep = io_remove_buffers_prep,
.issue = io_remove_buffers,
.issue = io_manage_buffers_legacy,
},
[IORING_OP_TEE] = {
.needs_file = 1,