Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : #include <linux/kernel.h>
3 : #include <linux/errno.h>
4 : #include <linux/fs.h>
5 : #include <linux/file.h>
6 : #include <linux/fdtable.h>
7 : #include <linux/fsnotify.h>
8 : #include <linux/namei.h>
9 : #include <linux/io_uring.h>
10 :
11 : #include <uapi/linux/io_uring.h>
12 :
13 : #include "../fs/internal.h"
14 :
15 : #include "io_uring.h"
16 : #include "rsrc.h"
17 : #include "openclose.h"
18 :
19 : struct io_open {
20 : struct file *file;
21 : int dfd;
22 : u32 file_slot;
23 : struct filename *filename;
24 : struct open_how how;
25 : unsigned long nofile;
26 : };
27 :
28 : struct io_close {
29 : struct file *file;
30 : int fd;
31 : u32 file_slot;
32 : };
33 :
34 : static bool io_openat_force_async(struct io_open *open)
35 : {
36 : /*
37 : * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open,
38 : * it'll always -EAGAIN
39 : */
40 0 : return open->how.flags & (O_TRUNC | O_CREAT | O_TMPFILE);
41 : }
42 :
43 0 : static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
44 : {
45 0 : struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
46 : const char __user *fname;
47 : int ret;
48 :
49 0 : if (unlikely(sqe->buf_index))
50 : return -EINVAL;
51 0 : if (unlikely(req->flags & REQ_F_FIXED_FILE))
52 : return -EBADF;
53 :
54 : /* open.how should be already initialised */
55 0 : if (!(open->how.flags & O_PATH) && force_o_largefile())
56 0 : open->how.flags |= O_LARGEFILE;
57 :
58 0 : open->dfd = READ_ONCE(sqe->fd);
59 0 : fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
60 0 : open->filename = getname(fname);
61 0 : if (IS_ERR(open->filename)) {
62 0 : ret = PTR_ERR(open->filename);
63 0 : open->filename = NULL;
64 0 : return ret;
65 : }
66 :
67 0 : open->file_slot = READ_ONCE(sqe->file_index);
68 0 : if (open->file_slot && (open->how.flags & O_CLOEXEC))
69 : return -EINVAL;
70 :
71 0 : open->nofile = rlimit(RLIMIT_NOFILE);
72 0 : req->flags |= REQ_F_NEED_CLEANUP;
73 0 : if (io_openat_force_async(open))
74 0 : req->flags |= REQ_F_FORCE_ASYNC;
75 : return 0;
76 : }
77 :
78 0 : int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
79 : {
80 0 : struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
81 0 : u64 mode = READ_ONCE(sqe->len);
82 0 : u64 flags = READ_ONCE(sqe->open_flags);
83 :
84 0 : open->how = build_open_how(flags, mode);
85 0 : return __io_openat_prep(req, sqe);
86 : }
87 :
88 0 : int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
89 : {
90 0 : struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
91 : struct open_how __user *how;
92 : size_t len;
93 : int ret;
94 :
95 0 : how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
96 0 : len = READ_ONCE(sqe->len);
97 0 : if (len < OPEN_HOW_SIZE_VER0)
98 : return -EINVAL;
99 :
100 0 : ret = copy_struct_from_user(&open->how, sizeof(open->how), how, len);
101 0 : if (ret)
102 : return ret;
103 :
104 0 : return __io_openat_prep(req, sqe);
105 : }
106 :
107 0 : int io_openat2(struct io_kiocb *req, unsigned int issue_flags)
108 : {
109 0 : struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
110 : struct open_flags op;
111 : struct file *file;
112 : bool resolve_nonblock, nonblock_set;
113 0 : bool fixed = !!open->file_slot;
114 : int ret;
115 :
116 0 : ret = build_open_flags(&open->how, &op);
117 0 : if (ret)
118 : goto err;
119 0 : nonblock_set = op.open_flag & O_NONBLOCK;
120 0 : resolve_nonblock = open->how.resolve & RESOLVE_CACHED;
121 0 : if (issue_flags & IO_URING_F_NONBLOCK) {
122 0 : WARN_ON_ONCE(io_openat_force_async(open));
123 0 : op.lookup_flags |= LOOKUP_CACHED;
124 0 : op.open_flag |= O_NONBLOCK;
125 : }
126 :
127 0 : if (!fixed) {
128 0 : ret = __get_unused_fd_flags(open->how.flags, open->nofile);
129 0 : if (ret < 0)
130 : goto err;
131 : }
132 :
133 0 : file = do_filp_open(open->dfd, open->filename, &op);
134 0 : if (IS_ERR(file)) {
135 : /*
136 : * We could hang on to this 'fd' on retrying, but seems like
137 : * marginal gain for something that is now known to be a slower
138 : * path. So just put it, and we'll get a new one when we retry.
139 : */
140 0 : if (!fixed)
141 0 : put_unused_fd(ret);
142 :
143 0 : ret = PTR_ERR(file);
144 : /* only retry if RESOLVE_CACHED wasn't already set by application */
145 0 : if (ret == -EAGAIN &&
146 0 : (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)))
147 : return -EAGAIN;
148 : goto err;
149 : }
150 :
151 0 : if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set)
152 0 : file->f_flags &= ~O_NONBLOCK;
153 :
154 0 : if (!fixed)
155 0 : fd_install(ret, file);
156 : else
157 0 : ret = io_fixed_fd_install(req, issue_flags, file,
158 : open->file_slot);
159 : err:
160 0 : putname(open->filename);
161 0 : req->flags &= ~REQ_F_NEED_CLEANUP;
162 0 : if (ret < 0)
163 0 : req_set_fail(req);
164 0 : io_req_set_res(req, ret, 0);
165 0 : return IOU_OK;
166 : }
167 :
168 0 : int io_openat(struct io_kiocb *req, unsigned int issue_flags)
169 : {
170 0 : return io_openat2(req, issue_flags);
171 : }
172 :
173 0 : void io_open_cleanup(struct io_kiocb *req)
174 : {
175 0 : struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
176 :
177 0 : if (open->filename)
178 0 : putname(open->filename);
179 0 : }
180 :
181 0 : int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags,
182 : unsigned int offset)
183 : {
184 : int ret;
185 :
186 0 : io_ring_submit_lock(ctx, issue_flags);
187 0 : ret = io_fixed_fd_remove(ctx, offset);
188 0 : io_ring_submit_unlock(ctx, issue_flags);
189 :
190 0 : return ret;
191 : }
192 :
193 : static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
194 : {
195 0 : struct io_close *close = io_kiocb_to_cmd(req, struct io_close);
196 :
197 0 : return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1);
198 : }
199 :
200 0 : int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
201 : {
202 0 : struct io_close *close = io_kiocb_to_cmd(req, struct io_close);
203 :
204 0 : if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index)
205 : return -EINVAL;
206 0 : if (req->flags & REQ_F_FIXED_FILE)
207 : return -EBADF;
208 :
209 0 : close->fd = READ_ONCE(sqe->fd);
210 0 : close->file_slot = READ_ONCE(sqe->file_index);
211 0 : if (close->file_slot && close->fd)
212 : return -EINVAL;
213 :
214 0 : return 0;
215 : }
216 :
217 0 : int io_close(struct io_kiocb *req, unsigned int issue_flags)
218 : {
219 0 : struct files_struct *files = current->files;
220 0 : struct io_close *close = io_kiocb_to_cmd(req, struct io_close);
221 : struct fdtable *fdt;
222 : struct file *file;
223 0 : int ret = -EBADF;
224 :
225 0 : if (close->file_slot) {
226 0 : ret = io_close_fixed(req, issue_flags);
227 0 : goto err;
228 : }
229 :
230 0 : spin_lock(&files->file_lock);
231 0 : fdt = files_fdtable(files);
232 0 : if (close->fd >= fdt->max_fds) {
233 0 : spin_unlock(&files->file_lock);
234 : goto err;
235 : }
236 0 : file = rcu_dereference_protected(fdt->fd[close->fd],
237 : lockdep_is_held(&files->file_lock));
238 0 : if (!file || io_is_uring_fops(file)) {
239 0 : spin_unlock(&files->file_lock);
240 : goto err;
241 : }
242 :
243 : /* if the file has a flush method, be safe and punt to async */
244 0 : if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) {
245 0 : spin_unlock(&files->file_lock);
246 0 : return -EAGAIN;
247 : }
248 :
249 0 : file = __close_fd_get_file(close->fd);
250 0 : spin_unlock(&files->file_lock);
251 0 : if (!file)
252 : goto err;
253 :
254 : /* No ->flush() or already async, safely close from here */
255 0 : ret = filp_close(file, current->files);
256 : err:
257 0 : if (ret < 0)
258 0 : req_set_fail(req);
259 0 : io_req_set_res(req, ret, 0);
260 0 : return IOU_OK;
261 : }
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