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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-09-15 12:03:38 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-19 05:49:53 -0600 |
| commit | 68fe256aadc0db70cb27132a6f5583819794d867 (patch) | |
| tree | 59891dbcdfa1ccee6706f980f6ac31bcd4294deb /fs/io_uring.c | |
| parent | a3f349071eb0ae2aa18ac2da55060865d8190cf0 (diff) | |
| download | lwn-68fe256aadc0db70cb27132a6f5583819794d867.tar.gz lwn-68fe256aadc0db70cb27132a6f5583819794d867.zip | |
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>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 027ca7a6df44..3801f2e5ea1b 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)); |