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io_uring: kbuf: kill __io_kbuf_recycle()

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__io_kbuf_recycle() is only called in io_kbuf_recycle(). Kill it and
tweak the code so that the legacy pbuf and ring pbuf code become clear

Signed-off-by: Hao Xu <howeyxu@tencent.com>
Link: https://lore.kernel.org/r/20220622055551.642370-1-hao.xu@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Hao Xu 2022-06-22 13:55:51 +08:00 committed by Jens Axboe
parent c6dd763c24
commit 024b8fde33
2 changed files with 49 additions and 43 deletions
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71
io_uring/kbuf.c
View File

@ -37,36 +37,30 @@ static inline struct io_buffer_list *io_buffer_get_list(struct io_ring_ctx *ctx,
return xa_load(&ctx->io_bl_xa, bgid);
}
void __io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
static int io_buffer_add_list(struct io_ring_ctx *ctx,
struct io_buffer_list *bl, unsigned int bgid)
{
bl->bgid = bgid;
if (bgid < BGID_ARRAY)
return 0;
return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL));
}
void io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer_list *bl;
struct io_buffer *buf;
/*
* We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
* the flag and hence ensure that bl->head doesn't get incremented.
* If the tail has already been incremented, hang on to it.
* For legacy provided buffer mode, don't recycle if we already did
* IO to this buffer. For ring-mapped provided buffer mode, we should
* increment ring->head to explicitly monopolize the buffer to avoid
* multiple use.
*/
if (req->flags & REQ_F_BUFFER_RING) {
if (req->buf_list) {
if (req->flags & REQ_F_PARTIAL_IO) {
/*
* If we end up here, then the io_uring_lock has
* been kept held since we retrieved the buffer.
* For the io-wq case, we already cleared
* req->buf_list when the buffer was retrieved,
* hence it cannot be set here for that case.
*/
req->buf_list->head++;
req->buf_list = NULL;
} else {
req->buf_index = req->buf_list->bgid;
req->flags &= ~REQ_F_BUFFER_RING;
}
}
if (req->flags & REQ_F_PARTIAL_IO)
return;
}
io_ring_submit_lock(ctx, issue_flags);
@ -77,16 +71,35 @@ void __io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
req->buf_index = buf->bgid;
io_ring_submit_unlock(ctx, issue_flags);
return;
}
static int io_buffer_add_list(struct io_ring_ctx *ctx,
struct io_buffer_list *bl, unsigned int bgid)
void io_kbuf_recycle_ring(struct io_kiocb *req)
{
bl->bgid = bgid;
if (bgid < BGID_ARRAY)
return 0;
return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL));
/*
* We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
* the flag and hence ensure that bl->head doesn't get incremented.
* If the tail has already been incremented, hang on to it.
* The exception is partial io, that case we should increment bl->head
* to monopolize the buffer.
*/
if (req->buf_list) {
if (req->flags & REQ_F_PARTIAL_IO) {
/*
* If we end up here, then the io_uring_lock has
* been kept held since we retrieved the buffer.
* For the io-wq case, we already cleared
* req->buf_list when the buffer was retrieved,
* hence it cannot be set here for that case.
*/
req->buf_list->head++;
req->buf_list = NULL;
} else {
req->buf_index = req->buf_list->bgid;
req->flags &= ~REQ_F_BUFFER_RING;
}
}
return;
}
unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags)

21
io_uring/kbuf.h
View File

@ -35,7 +35,6 @@ struct io_buffer {
void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
unsigned int issue_flags);
void __io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags);
void io_destroy_buffers(struct io_ring_ctx *ctx);
int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
@ -49,6 +48,9 @@ int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags);
void io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags);
void io_kbuf_recycle_ring(struct io_kiocb *req);
static inline bool io_do_buffer_select(struct io_kiocb *req)
{
if (!(req->flags & REQ_F_BUFFER_SELECT))
@ -58,18 +60,6 @@ static inline bool io_do_buffer_select(struct io_kiocb *req)
static inline void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
{
if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)))
return;
/*
* For legacy provided buffer mode, don't recycle if we already did
* IO to this buffer. For ring-mapped provided buffer mode, we should
* increment ring->head to explicitly monopolize the buffer to avoid
* multiple use.
*/
if ((req->flags & REQ_F_BUFFER_SELECTED) &&
(req->flags & REQ_F_PARTIAL_IO))
return;
/*
* READV uses fields in `struct io_rw` (len/addr) to stash the selected
* buffer data. However if that buffer is recycled the original request
@ -78,7 +68,10 @@ static inline void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
if (req->opcode == IORING_OP_READV)
return;
__io_kbuf_recycle(req, issue_flags);
if (req->flags & REQ_F_BUFFER_SELECTED)
io_kbuf_recycle_legacy(req, issue_flags);
if (req->flags & REQ_F_BUFFER_RING)
io_kbuf_recycle_ring(req);
}
static inline unsigned int __io_put_kbuf_list(struct io_kiocb *req,