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b54a14041e
There are lots of spots open-coding this functionality, add a generic helper that does the node lookup in a speculation safe way. Signed-off-by: Jens Axboe <axboe@kernel.dk>
81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/io_uring.h>
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#include <uapi/linux/io_uring.h>
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#include "io_uring.h"
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#include "rsrc.h"
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#include "nop.h"
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struct io_nop {
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/* NOTE: kiocb has the file as the first member, so don't do it here */
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struct file *file;
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int result;
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int fd;
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int buffer;
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unsigned int flags;
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};
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#define NOP_FLAGS (IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \
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IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE)
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int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
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{
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struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
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nop->flags = READ_ONCE(sqe->nop_flags);
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if (nop->flags & ~NOP_FLAGS)
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return -EINVAL;
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if (nop->flags & IORING_NOP_INJECT_RESULT)
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nop->result = READ_ONCE(sqe->len);
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else
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nop->result = 0;
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if (nop->flags & IORING_NOP_FIXED_FILE)
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nop->fd = READ_ONCE(sqe->fd);
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if (nop->flags & IORING_NOP_FIXED_BUFFER)
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nop->buffer = READ_ONCE(sqe->buf_index);
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return 0;
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}
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int io_nop(struct io_kiocb *req, unsigned int issue_flags)
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{
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struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
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int ret = nop->result;
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if (nop->flags & IORING_NOP_FILE) {
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if (nop->flags & IORING_NOP_FIXED_FILE) {
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req->file = io_file_get_fixed(req, nop->fd, issue_flags);
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req->flags |= REQ_F_FIXED_FILE;
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} else {
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req->file = io_file_get_normal(req, nop->fd);
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}
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if (!req->file) {
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ret = -EBADF;
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goto done;
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}
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}
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if (nop->flags & IORING_NOP_FIXED_BUFFER) {
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struct io_ring_ctx *ctx = req->ctx;
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struct io_rsrc_node *node;
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ret = -EFAULT;
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io_ring_submit_lock(ctx, issue_flags);
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node = io_rsrc_node_lookup(&ctx->buf_table, nop->buffer);
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if (node) {
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io_req_assign_rsrc_node(req, node);
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ret = 0;
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}
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io_ring_submit_unlock(ctx, issue_flags);
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}
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done:
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if (ret < 0)
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req_set_fail(req);
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io_req_set_res(req, nop->result, 0);
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return IOU_OK;
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}
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