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cd40cae2 JA |
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 | ||
cd40cae2 | 15 | #include "io_uring.h" |
73572984 | 16 | #include "rsrc.h" |
cd40cae2 JA |
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 | ||
dc18b89a JA |
34 | struct io_fixed_install { |
35 | struct file *file; | |
36 | unsigned int o_flags; | |
37 | }; | |
38 | ||
0ffae640 DY |
39 | static bool io_openat_force_async(struct io_open *open) |
40 | { | |
41 | /* | |
42 | * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, | |
72dbde0f AS |
43 | * it'll always -EAGAIN. Note that we test for __O_TMPFILE because |
44 | * O_TMPFILE includes O_DIRECTORY, which isn't a flag we need to force | |
45 | * async for. | |
0ffae640 | 46 | */ |
72dbde0f | 47 | return open->how.flags & (O_TRUNC | O_CREAT | __O_TMPFILE); |
0ffae640 DY |
48 | } |
49 | ||
cd40cae2 JA |
50 | static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
51 | { | |
f2ccb5ae | 52 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
53 | const char __user *fname; |
54 | int ret; | |
55 | ||
56 | if (unlikely(sqe->buf_index)) | |
57 | return -EINVAL; | |
58 | if (unlikely(req->flags & REQ_F_FIXED_FILE)) | |
59 | return -EBADF; | |
60 | ||
61 | /* open.how should be already initialised */ | |
62 | if (!(open->how.flags & O_PATH) && force_o_largefile()) | |
63 | open->how.flags |= O_LARGEFILE; | |
64 | ||
65 | open->dfd = READ_ONCE(sqe->fd); | |
66 | fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); | |
67 | open->filename = getname(fname); | |
68 | if (IS_ERR(open->filename)) { | |
69 | ret = PTR_ERR(open->filename); | |
70 | open->filename = NULL; | |
71 | return ret; | |
72 | } | |
73 | ||
74 | open->file_slot = READ_ONCE(sqe->file_index); | |
75 | if (open->file_slot && (open->how.flags & O_CLOEXEC)) | |
76 | return -EINVAL; | |
77 | ||
78 | open->nofile = rlimit(RLIMIT_NOFILE); | |
79 | req->flags |= REQ_F_NEED_CLEANUP; | |
0ffae640 DY |
80 | if (io_openat_force_async(open)) |
81 | req->flags |= REQ_F_FORCE_ASYNC; | |
cd40cae2 JA |
82 | return 0; |
83 | } | |
84 | ||
85 | int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
86 | { | |
f2ccb5ae | 87 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
88 | u64 mode = READ_ONCE(sqe->len); |
89 | u64 flags = READ_ONCE(sqe->open_flags); | |
90 | ||
91 | open->how = build_open_how(flags, mode); | |
92 | return __io_openat_prep(req, sqe); | |
93 | } | |
94 | ||
95 | int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
96 | { | |
f2ccb5ae | 97 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
98 | struct open_how __user *how; |
99 | size_t len; | |
100 | int ret; | |
101 | ||
102 | how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); | |
103 | len = READ_ONCE(sqe->len); | |
104 | if (len < OPEN_HOW_SIZE_VER0) | |
105 | return -EINVAL; | |
106 | ||
107 | ret = copy_struct_from_user(&open->how, sizeof(open->how), how, len); | |
108 | if (ret) | |
109 | return ret; | |
110 | ||
111 | return __io_openat_prep(req, sqe); | |
112 | } | |
113 | ||
114 | int io_openat2(struct io_kiocb *req, unsigned int issue_flags) | |
115 | { | |
f2ccb5ae | 116 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
117 | struct open_flags op; |
118 | struct file *file; | |
119 | bool resolve_nonblock, nonblock_set; | |
120 | bool fixed = !!open->file_slot; | |
121 | int ret; | |
122 | ||
123 | ret = build_open_flags(&open->how, &op); | |
124 | if (ret) | |
125 | goto err; | |
126 | nonblock_set = op.open_flag & O_NONBLOCK; | |
127 | resolve_nonblock = open->how.resolve & RESOLVE_CACHED; | |
128 | if (issue_flags & IO_URING_F_NONBLOCK) { | |
0ffae640 | 129 | WARN_ON_ONCE(io_openat_force_async(open)); |
cd40cae2 JA |
130 | op.lookup_flags |= LOOKUP_CACHED; |
131 | op.open_flag |= O_NONBLOCK; | |
132 | } | |
133 | ||
134 | if (!fixed) { | |
135 | ret = __get_unused_fd_flags(open->how.flags, open->nofile); | |
136 | if (ret < 0) | |
137 | goto err; | |
138 | } | |
139 | ||
140 | file = do_filp_open(open->dfd, open->filename, &op); | |
141 | if (IS_ERR(file)) { | |
142 | /* | |
143 | * We could hang on to this 'fd' on retrying, but seems like | |
144 | * marginal gain for something that is now known to be a slower | |
145 | * path. So just put it, and we'll get a new one when we retry. | |
146 | */ | |
147 | if (!fixed) | |
148 | put_unused_fd(ret); | |
149 | ||
150 | ret = PTR_ERR(file); | |
151 | /* only retry if RESOLVE_CACHED wasn't already set by application */ | |
152 | if (ret == -EAGAIN && | |
153 | (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK))) | |
154 | return -EAGAIN; | |
155 | goto err; | |
156 | } | |
157 | ||
158 | if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) | |
159 | file->f_flags &= ~O_NONBLOCK; | |
cd40cae2 JA |
160 | |
161 | if (!fixed) | |
162 | fd_install(ret, file); | |
163 | else | |
164 | ret = io_fixed_fd_install(req, issue_flags, file, | |
165 | open->file_slot); | |
166 | err: | |
167 | putname(open->filename); | |
168 | req->flags &= ~REQ_F_NEED_CLEANUP; | |
169 | if (ret < 0) | |
170 | req_set_fail(req); | |
171 | io_req_set_res(req, ret, 0); | |
172 | return IOU_OK; | |
173 | } | |
174 | ||
175 | int io_openat(struct io_kiocb *req, unsigned int issue_flags) | |
176 | { | |
177 | return io_openat2(req, issue_flags); | |
178 | } | |
179 | ||
180 | void io_open_cleanup(struct io_kiocb *req) | |
181 | { | |
f2ccb5ae | 182 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
183 | |
184 | if (open->filename) | |
185 | putname(open->filename); | |
186 | } | |
187 | ||
f110ed84 | 188 | int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags, |
cd40cae2 JA |
189 | unsigned int offset) |
190 | { | |
cd40cae2 JA |
191 | int ret; |
192 | ||
193 | io_ring_submit_lock(ctx, issue_flags); | |
f110ed84 | 194 | ret = io_fixed_fd_remove(ctx, offset); |
cd40cae2 | 195 | io_ring_submit_unlock(ctx, issue_flags); |
f110ed84 | 196 | |
cd40cae2 JA |
197 | return ret; |
198 | } | |
199 | ||
200 | static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags) | |
201 | { | |
f2ccb5ae | 202 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 | 203 | |
f110ed84 | 204 | return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1); |
cd40cae2 JA |
205 | } |
206 | ||
207 | int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
208 | { | |
f2ccb5ae | 209 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 JA |
210 | |
211 | if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) | |
212 | return -EINVAL; | |
213 | if (req->flags & REQ_F_FIXED_FILE) | |
214 | return -EBADF; | |
215 | ||
216 | close->fd = READ_ONCE(sqe->fd); | |
217 | close->file_slot = READ_ONCE(sqe->file_index); | |
218 | if (close->file_slot && close->fd) | |
219 | return -EINVAL; | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | int io_close(struct io_kiocb *req, unsigned int issue_flags) | |
225 | { | |
226 | struct files_struct *files = current->files; | |
f2ccb5ae | 227 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 JA |
228 | struct file *file; |
229 | int ret = -EBADF; | |
230 | ||
231 | if (close->file_slot) { | |
232 | ret = io_close_fixed(req, issue_flags); | |
233 | goto err; | |
234 | } | |
235 | ||
236 | spin_lock(&files->file_lock); | |
50d910d2 | 237 | file = files_lookup_fd_locked(files, close->fd); |
cd40cae2 JA |
238 | if (!file || io_is_uring_fops(file)) { |
239 | 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 | if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { | |
245 | spin_unlock(&files->file_lock); | |
246 | return -EAGAIN; | |
247 | } | |
248 | ||
24fa3ae9 | 249 | file = file_close_fd_locked(files, close->fd); |
cd40cae2 JA |
250 | spin_unlock(&files->file_lock); |
251 | if (!file) | |
252 | goto err; | |
253 | ||
254 | /* No ->flush() or already async, safely close from here */ | |
255 | ret = filp_close(file, current->files); | |
256 | err: | |
257 | if (ret < 0) | |
258 | req_set_fail(req); | |
259 | io_req_set_res(req, ret, 0); | |
260 | return IOU_OK; | |
261 | } | |
dc18b89a JA |
262 | |
263 | int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
264 | { | |
265 | struct io_fixed_install *ifi; | |
266 | unsigned int flags; | |
267 | ||
268 | if (sqe->off || sqe->addr || sqe->len || sqe->buf_index || | |
269 | sqe->splice_fd_in || sqe->addr3) | |
270 | return -EINVAL; | |
271 | ||
272 | /* must be a fixed file */ | |
273 | if (!(req->flags & REQ_F_FIXED_FILE)) | |
274 | return -EBADF; | |
275 | ||
276 | flags = READ_ONCE(sqe->install_fd_flags); | |
277 | if (flags & ~IORING_FIXED_FD_NO_CLOEXEC) | |
278 | return -EINVAL; | |
279 | ||
16bae3e1 PM |
280 | /* ensure the task's creds are used when installing/receiving fds */ |
281 | if (req->flags & REQ_F_CREDS) | |
282 | return -EPERM; | |
283 | ||
dc18b89a JA |
284 | /* default to O_CLOEXEC, disable if IORING_FIXED_FD_NO_CLOEXEC is set */ |
285 | ifi = io_kiocb_to_cmd(req, struct io_fixed_install); | |
286 | ifi->o_flags = O_CLOEXEC; | |
287 | if (flags & IORING_FIXED_FD_NO_CLOEXEC) | |
288 | ifi->o_flags = 0; | |
289 | ||
290 | return 0; | |
291 | } | |
292 | ||
293 | int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags) | |
294 | { | |
295 | struct io_fixed_install *ifi; | |
296 | int ret; | |
297 | ||
298 | ifi = io_kiocb_to_cmd(req, struct io_fixed_install); | |
299 | ret = receive_fd(req->file, NULL, ifi->o_flags); | |
300 | if (ret < 0) | |
301 | req_set_fail(req); | |
302 | io_req_set_res(req, ret, 0); | |
303 | return IOU_OK; | |
304 | } |