From 68fe256aadc0db70cb27132a6f5583819794d867 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 15 Sep 2021 12:03:38 +0100 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/dccfb9ab2ab0969a2d8dc59af88fa0ce44eeb1d5.1631703764.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 027ca7a..3801f2e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -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)); -- 2.7.4