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io_uring: optimise io_req_init() sqe flags checks 

IOSQE_IO_DRAIN is quite marginal and we don't care too much about
IOSQE_BUFFER_SELECT. Save to ifs and hide both of them under
SQE_VALID_FLAGS check. Now we first check whether it uses a "safe"
subset, i.e. without DRAIN and BUFFER_SELECT, and only if it's not
true we test the rest of the flags.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dccfb9ab2ab0969a2d8dc59af88fa0ce44eeb1d5.1631703764.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-09-15 12:03:38 +01:00 committed by Jens Axboe
parent a3f349071e
commit 68fe256aad
1 changed files with 17 additions and 12 deletions
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29
fs/io_uring.c
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@ -103,9 +103,11 @@
#define IORING_MAX_REG_BUFFERS (1U << 14)
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
IOSQE_BUFFER_SELECT)
#define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
IOSQE_IO_HARDLINK | IOSQE_ASYNC)
#define SQE_VALID_FLAGS (SQE_COMMON_FLAGS|IOSQE_BUFFER_SELECT|IOSQE_IO_DRAIN)
#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS)
@ -7059,20 +7061,21 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
req->fixed_rsrc_refs = NULL;
req->task = current;
/* 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(sqe_flags & ~SQE_COMMON_FLAGS)) {
/* enforce forwards compatibility on users */
if (sqe_flags & ~SQE_VALID_FLAGS)
return -EINVAL;
if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
!io_op_defs[req->opcode].buffer_select)
return -EOPNOTSUPP;
if (sqe_flags & IOSQE_IO_DRAIN)
ctx->drain_active = true;
}
if (!io_check_restriction(ctx, req, sqe_flags))
return -EACCES;
if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
!io_op_defs[req->opcode].buffer_select)
return -EOPNOTSUPP;
if (unlikely(sqe_flags & IOSQE_IO_DRAIN))
ctx->drain_active = true;
personality = READ_ONCE(sqe->personality);
if (personality) {
req->creds = xa_load(&ctx->personalities, personality);
@ -11017,6 +11020,8 @@ static int __init io_uring_init(void)
/* should fit into one byte */
BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
BUILD_BUG_ON(SQE_COMMON_FLAGS >= (1 << 8));
BUILD_BUG_ON((SQE_VALID_FLAGS | SQE_COMMON_FLAGS) != SQE_VALID_FLAGS);
BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));