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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 | ||
34 | static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
35 | { | |
f2ccb5ae | 36 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
37 | const char __user *fname; |
38 | int ret; | |
39 | ||
40 | if (unlikely(sqe->buf_index)) | |
41 | return -EINVAL; | |
42 | if (unlikely(req->flags & REQ_F_FIXED_FILE)) | |
43 | return -EBADF; | |
44 | ||
45 | /* open.how should be already initialised */ | |
46 | if (!(open->how.flags & O_PATH) && force_o_largefile()) | |
47 | open->how.flags |= O_LARGEFILE; | |
48 | ||
49 | open->dfd = READ_ONCE(sqe->fd); | |
50 | fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); | |
51 | open->filename = getname(fname); | |
52 | if (IS_ERR(open->filename)) { | |
53 | ret = PTR_ERR(open->filename); | |
54 | open->filename = NULL; | |
55 | return ret; | |
56 | } | |
57 | ||
58 | open->file_slot = READ_ONCE(sqe->file_index); | |
59 | if (open->file_slot && (open->how.flags & O_CLOEXEC)) | |
60 | return -EINVAL; | |
61 | ||
62 | open->nofile = rlimit(RLIMIT_NOFILE); | |
63 | req->flags |= REQ_F_NEED_CLEANUP; | |
64 | return 0; | |
65 | } | |
66 | ||
67 | int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
68 | { | |
f2ccb5ae | 69 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
70 | u64 mode = READ_ONCE(sqe->len); |
71 | u64 flags = READ_ONCE(sqe->open_flags); | |
72 | ||
73 | open->how = build_open_how(flags, mode); | |
74 | return __io_openat_prep(req, sqe); | |
75 | } | |
76 | ||
77 | int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
78 | { | |
f2ccb5ae | 79 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
80 | struct open_how __user *how; |
81 | size_t len; | |
82 | int ret; | |
83 | ||
84 | how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); | |
85 | len = READ_ONCE(sqe->len); | |
86 | if (len < OPEN_HOW_SIZE_VER0) | |
87 | return -EINVAL; | |
88 | ||
89 | ret = copy_struct_from_user(&open->how, sizeof(open->how), how, len); | |
90 | if (ret) | |
91 | return ret; | |
92 | ||
93 | return __io_openat_prep(req, sqe); | |
94 | } | |
95 | ||
96 | int io_openat2(struct io_kiocb *req, unsigned int issue_flags) | |
97 | { | |
f2ccb5ae | 98 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
99 | struct open_flags op; |
100 | struct file *file; | |
101 | bool resolve_nonblock, nonblock_set; | |
102 | bool fixed = !!open->file_slot; | |
103 | int ret; | |
104 | ||
105 | ret = build_open_flags(&open->how, &op); | |
106 | if (ret) | |
107 | goto err; | |
108 | nonblock_set = op.open_flag & O_NONBLOCK; | |
109 | resolve_nonblock = open->how.resolve & RESOLVE_CACHED; | |
110 | if (issue_flags & IO_URING_F_NONBLOCK) { | |
111 | /* | |
112 | * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, | |
113 | * it'll always -EAGAIN | |
114 | */ | |
115 | if (open->how.flags & (O_TRUNC | O_CREAT | O_TMPFILE)) | |
116 | return -EAGAIN; | |
117 | op.lookup_flags |= LOOKUP_CACHED; | |
118 | op.open_flag |= O_NONBLOCK; | |
119 | } | |
120 | ||
121 | if (!fixed) { | |
122 | ret = __get_unused_fd_flags(open->how.flags, open->nofile); | |
123 | if (ret < 0) | |
124 | goto err; | |
125 | } | |
126 | ||
127 | file = do_filp_open(open->dfd, open->filename, &op); | |
128 | if (IS_ERR(file)) { | |
129 | /* | |
130 | * We could hang on to this 'fd' on retrying, but seems like | |
131 | * marginal gain for something that is now known to be a slower | |
132 | * path. So just put it, and we'll get a new one when we retry. | |
133 | */ | |
134 | if (!fixed) | |
135 | put_unused_fd(ret); | |
136 | ||
137 | ret = PTR_ERR(file); | |
138 | /* only retry if RESOLVE_CACHED wasn't already set by application */ | |
139 | if (ret == -EAGAIN && | |
140 | (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK))) | |
141 | return -EAGAIN; | |
142 | goto err; | |
143 | } | |
144 | ||
145 | if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) | |
146 | file->f_flags &= ~O_NONBLOCK; | |
147 | fsnotify_open(file); | |
148 | ||
149 | if (!fixed) | |
150 | fd_install(ret, file); | |
151 | else | |
152 | ret = io_fixed_fd_install(req, issue_flags, file, | |
153 | open->file_slot); | |
154 | err: | |
155 | putname(open->filename); | |
156 | req->flags &= ~REQ_F_NEED_CLEANUP; | |
157 | if (ret < 0) | |
158 | req_set_fail(req); | |
159 | io_req_set_res(req, ret, 0); | |
160 | return IOU_OK; | |
161 | } | |
162 | ||
163 | int io_openat(struct io_kiocb *req, unsigned int issue_flags) | |
164 | { | |
165 | return io_openat2(req, issue_flags); | |
166 | } | |
167 | ||
168 | void io_open_cleanup(struct io_kiocb *req) | |
169 | { | |
f2ccb5ae | 170 | struct io_open *open = io_kiocb_to_cmd(req, struct io_open); |
cd40cae2 JA |
171 | |
172 | if (open->filename) | |
173 | putname(open->filename); | |
174 | } | |
175 | ||
f110ed84 | 176 | int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags, |
cd40cae2 JA |
177 | unsigned int offset) |
178 | { | |
cd40cae2 JA |
179 | int ret; |
180 | ||
181 | io_ring_submit_lock(ctx, issue_flags); | |
f110ed84 | 182 | ret = io_fixed_fd_remove(ctx, offset); |
cd40cae2 | 183 | io_ring_submit_unlock(ctx, issue_flags); |
f110ed84 | 184 | |
cd40cae2 JA |
185 | return ret; |
186 | } | |
187 | ||
188 | static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags) | |
189 | { | |
f2ccb5ae | 190 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 | 191 | |
f110ed84 | 192 | return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1); |
cd40cae2 JA |
193 | } |
194 | ||
195 | int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
196 | { | |
f2ccb5ae | 197 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 JA |
198 | |
199 | if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) | |
200 | return -EINVAL; | |
201 | if (req->flags & REQ_F_FIXED_FILE) | |
202 | return -EBADF; | |
203 | ||
204 | close->fd = READ_ONCE(sqe->fd); | |
205 | close->file_slot = READ_ONCE(sqe->file_index); | |
206 | if (close->file_slot && close->fd) | |
207 | return -EINVAL; | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
212 | int io_close(struct io_kiocb *req, unsigned int issue_flags) | |
213 | { | |
214 | struct files_struct *files = current->files; | |
f2ccb5ae | 215 | struct io_close *close = io_kiocb_to_cmd(req, struct io_close); |
cd40cae2 JA |
216 | struct fdtable *fdt; |
217 | struct file *file; | |
218 | int ret = -EBADF; | |
219 | ||
220 | if (close->file_slot) { | |
221 | ret = io_close_fixed(req, issue_flags); | |
222 | goto err; | |
223 | } | |
224 | ||
225 | spin_lock(&files->file_lock); | |
226 | fdt = files_fdtable(files); | |
227 | if (close->fd >= fdt->max_fds) { | |
228 | spin_unlock(&files->file_lock); | |
229 | goto err; | |
230 | } | |
231 | file = rcu_dereference_protected(fdt->fd[close->fd], | |
232 | lockdep_is_held(&files->file_lock)); | |
233 | if (!file || io_is_uring_fops(file)) { | |
234 | spin_unlock(&files->file_lock); | |
235 | goto err; | |
236 | } | |
237 | ||
238 | /* if the file has a flush method, be safe and punt to async */ | |
239 | if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { | |
240 | spin_unlock(&files->file_lock); | |
241 | return -EAGAIN; | |
242 | } | |
243 | ||
244 | file = __close_fd_get_file(close->fd); | |
245 | spin_unlock(&files->file_lock); | |
246 | if (!file) | |
247 | goto err; | |
248 | ||
249 | /* No ->flush() or already async, safely close from here */ | |
250 | ret = filp_close(file, current->files); | |
251 | err: | |
252 | if (ret < 0) | |
253 | req_set_fail(req); | |
254 | io_req_set_res(req, ret, 0); | |
255 | return IOU_OK; | |
256 | } |