diff options
author | Jens Axboe <axboe@kernel.dk> | 2022-03-10 06:27:26 -0700 |
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committer | Jens Axboe <axboe@kernel.dk> | 2022-03-10 09:16:04 -0700 |
commit | 4f57f06ce2186c31c3da52386125dc57b1cd6f96 (patch) | |
tree | 6f5f47b26c3b1a5c0de6ce92069d8c28f93d7069 /fs/io_uring.c | |
parent | cc3cec8367cba76a8ae4c271eba8450f3efc1ba3 (diff) | |
download | linux-4f57f06ce2186c31c3da52386125dc57b1cd6f96.tar.bz2 |
io_uring: add support for IORING_OP_MSG_RING command
This adds support for IORING_OP_MSG_RING, which allows an SQE to signal
another ring. That allows either waking up someone waiting on the ring,
or even passing a 64-bit value via the user_data field in the CQE.
sqe->fd must contain the fd of a ring that should receive the CQE.
sqe->off will be propagated to the cqe->user_data on the target ring,
and sqe->len will be propagated to cqe->res. The results CQE will have
IORING_CQE_F_MSG set in its flags, to indicate that this CQE was generated
from a messaging request rather than a SQE issued locally on that ring.
This effectively allows passing a 64-bit and a 32-bit quantify between
the two rings.
This request type has the following request specific error cases:
- -EBADFD. Set if the sqe->fd doesn't point to a file descriptor that is
of the io_uring type.
- -EOVERFLOW. Set if we were not able to deliver a request to the target
ring.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r-- | fs/io_uring.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 0f5e999e569f..36b001365a79 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -706,6 +706,12 @@ struct io_hardlink { int flags; }; +struct io_msg { + struct file *file; + u64 user_data; + u32 len; +}; + struct io_async_connect { struct sockaddr_storage address; }; @@ -871,6 +877,7 @@ struct io_kiocb { struct io_mkdir mkdir; struct io_symlink symlink; struct io_hardlink hardlink; + struct io_msg msg; }; u8 opcode; @@ -1121,6 +1128,9 @@ static const struct io_op_def io_op_defs[] = { [IORING_OP_MKDIRAT] = {}, [IORING_OP_SYMLINKAT] = {}, [IORING_OP_LINKAT] = {}, + [IORING_OP_MSG_RING] = { + .needs_file = 1, + }, }; /* requests with any of those set should undergo io_disarm_next() */ @@ -4322,6 +4332,46 @@ static int io_nop(struct io_kiocb *req, unsigned int issue_flags) return 0; } +static int io_msg_ring_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index || + sqe->rw_flags || sqe->splice_fd_in || sqe->buf_index || + sqe->personality)) + return -EINVAL; + + if (req->file->f_op != &io_uring_fops) + return -EBADFD; + + req->msg.user_data = READ_ONCE(sqe->off); + req->msg.len = READ_ONCE(sqe->len); + return 0; +} + +static int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *target_ctx; + struct io_msg *msg = &req->msg; + int ret = -EOVERFLOW; + bool filled; + + target_ctx = req->file->private_data; + + spin_lock(&target_ctx->completion_lock); + filled = io_fill_cqe_aux(target_ctx, msg->user_data, msg->len, + IORING_CQE_F_MSG); + io_commit_cqring(target_ctx); + spin_unlock(&target_ctx->completion_lock); + + if (filled) { + io_cqring_ev_posted(target_ctx); + ret = 0; + } + + __io_req_complete(req, issue_flags, ret, 0); + return 0; +} + static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_ring_ctx *ctx = req->ctx; @@ -6700,6 +6750,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return io_symlinkat_prep(req, sqe); case IORING_OP_LINKAT: return io_linkat_prep(req, sqe); + case IORING_OP_MSG_RING: + return io_msg_ring_prep(req, sqe); } printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", @@ -6983,6 +7035,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) case IORING_OP_LINKAT: ret = io_linkat(req, issue_flags); break; + case IORING_OP_MSG_RING: + ret = io_msg_ring(req, issue_flags); + break; default: ret = -EINVAL; break; |