From 4d954c258a0c365a85a2d1b1cccf63aec38fca4c Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 27 Feb 2020 07:31:19 -0700 Subject: io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_READV This adds support for the vectored read. This is limited to supporting just 1 segment in the iov, and is provided just for convenience for applications that use IORING_OP_READV already. The iov helpers will be used for IORING_OP_RECVMSG as well. Signed-off-by: Jens Axboe --- fs/io_uring.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 97 insertions(+), 14 deletions(-) (limited to 'fs/io_uring.c') diff --git a/fs/io_uring.c b/fs/io_uring.c index a80b5c189c14..7c855a038a1b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -682,6 +682,7 @@ static const struct io_op_def io_op_defs[] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, + .buffer_select = 1, }, [IORING_OP_WRITEV] = { .async_ctx = 1, @@ -1686,9 +1687,10 @@ static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req) static int io_put_kbuf(struct io_kiocb *req) { - struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr; + struct io_buffer *kbuf; int cflags; + kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT; cflags |= IORING_CQE_F_BUFFER; req->rw.addr = 0; @@ -2242,12 +2244,95 @@ static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len, return kbuf; } +static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len, + bool needs_lock) +{ + struct io_buffer *kbuf; + int bgid; + + kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; + bgid = (int) (unsigned long) req->rw.kiocb.private; + kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock); + if (IS_ERR(kbuf)) + return kbuf; + req->rw.addr = (u64) (unsigned long) kbuf; + req->flags |= REQ_F_BUFFER_SELECTED; + return u64_to_user_ptr(kbuf->addr); +} + +#ifdef CONFIG_COMPAT +static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov, + bool needs_lock) +{ + struct compat_iovec __user *uiov; + compat_ssize_t clen; + void __user *buf; + ssize_t len; + + uiov = u64_to_user_ptr(req->rw.addr); + if (!access_ok(uiov, sizeof(*uiov))) + return -EFAULT; + if (__get_user(clen, &uiov->iov_len)) + return -EFAULT; + if (clen < 0) + return -EINVAL; + + len = clen; + buf = io_rw_buffer_select(req, &len, needs_lock); + if (IS_ERR(buf)) + return PTR_ERR(buf); + iov[0].iov_base = buf; + iov[0].iov_len = (compat_size_t) len; + return 0; +} +#endif + +static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, + bool needs_lock) +{ + struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr); + void __user *buf; + ssize_t len; + + if (copy_from_user(iov, uiov, sizeof(*uiov))) + return -EFAULT; + + len = iov[0].iov_len; + if (len < 0) + return -EINVAL; + buf = io_rw_buffer_select(req, &len, needs_lock); + if (IS_ERR(buf)) + return PTR_ERR(buf); + iov[0].iov_base = buf; + iov[0].iov_len = len; + return 0; +} + +static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, + bool needs_lock) +{ + if (req->flags & REQ_F_BUFFER_SELECTED) + return 0; + if (!req->rw.len) + return 0; + else if (req->rw.len > 1) + return -EINVAL; + +#ifdef CONFIG_COMPAT + if (req->ctx->compat) + return io_compat_import(req, iov, needs_lock); +#endif + + return __io_iov_buffer_select(req, iov, needs_lock); +} + static ssize_t io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, struct iov_iter *iter, bool needs_lock) { void __user *buf = u64_to_user_ptr(req->rw.addr); size_t sqe_len = req->rw.len; + ssize_t ret; u8 opcode; opcode = req->opcode; @@ -2261,22 +2346,12 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req, return -EINVAL; if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) { - ssize_t ret; - if (req->flags & REQ_F_BUFFER_SELECT) { - struct io_buffer *kbuf = (struct io_buffer *) req->rw.addr; - int bgid; - - bgid = (int) (unsigned long) req->rw.kiocb.private; - kbuf = io_buffer_select(req, &sqe_len, bgid, kbuf, - needs_lock); - if (IS_ERR(kbuf)) { + buf = io_rw_buffer_select(req, &sqe_len, needs_lock); + if (IS_ERR(buf)) { *iovec = NULL; - return PTR_ERR(kbuf); + return PTR_ERR(buf); } - req->rw.addr = (u64) kbuf; - req->flags |= REQ_F_BUFFER_SELECTED; - buf = u64_to_user_ptr(kbuf->addr); } ret = import_single_range(rw, buf, sqe_len, *iovec, iter); @@ -2294,6 +2369,14 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req, return iorw->size; } + if (req->flags & REQ_F_BUFFER_SELECT) { + ret = io_iov_buffer_select(req, *iovec, needs_lock); + if (!ret) + iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len); + *iovec = NULL; + return ret; + } + #ifdef CONFIG_COMPAT if (req->ctx->compat) return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, -- cgit