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io_uring: optimise io_init_req() flags setting

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Invalid req->flags are tolerated by free/put well, avoid this dancing
needlessly presetting it to zero, and then not even resetting but
modifying it, i.e. "|=".

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-02-12 18:41:17 +00:00 committed by Jens Axboe
parent cdbff98223
commit 5be9ad1e42
1 changed files with 7 additions and 10 deletions
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17
fs/io_uring.c
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@ -6806,14 +6806,15 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
{
struct io_submit_state *state;
unsigned int sqe_flags;
int id, ret;
int id, ret = 0;
req->opcode = READ_ONCE(sqe->opcode);
/* same numerical values with corresponding REQ_F_*, safe to copy */
req->flags = sqe_flags = READ_ONCE(sqe->flags);
req->user_data = READ_ONCE(sqe->user_data);
req->async_data = NULL;
req->file = NULL;
req->ctx = ctx;
req->flags = 0;
req->link = NULL;
req->fixed_rsrc_refs = NULL;
/* one is dropped after submission, the other at completion */
@ -6821,17 +6822,16 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
req->task = current;
req->result = 0;
/* enforce forwards compatibility on users */
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
return -EINVAL;
if (unlikely(req->opcode >= IORING_OP_LAST))
return -EINVAL;
if (unlikely(io_sq_thread_acquire_mm_files(ctx, req)))
return -EFAULT;
sqe_flags = READ_ONCE(sqe->flags);
/* enforce forwards compatibility on users */
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
return -EINVAL;
if (unlikely(!io_check_restriction(ctx, req, sqe_flags)))
return -EACCES;
@ -6854,8 +6854,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
req->work.flags |= IO_WQ_WORK_CREDS;
}
/* same numerical values with corresponding REQ_F_*, safe to copy */
req->flags |= sqe_flags;
state = &ctx->submit_state;
/*
@ -6868,7 +6866,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
state->plug_started = true;
}
ret = 0;
if (io_op_defs[req->opcode].needs_file) {
bool fixed = req->flags & REQ_F_FIXED_FILE;