Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d1d04ef8 MS |
2 | /* |
3 | * Copyright (C) 2017 Red Hat, Inc. | |
d1d04ef8 MS |
4 | */ |
5 | ||
6 | #include <linux/cred.h> | |
7 | #include <linux/file.h> | |
dab5ca8f | 8 | #include <linux/mount.h> |
d1d04ef8 | 9 | #include <linux/xattr.h> |
16914e6f | 10 | #include <linux/uio.h> |
98487de3 | 11 | #include <linux/uaccess.h> |
1a980b8c | 12 | #include <linux/splice.h> |
292f902a | 13 | #include <linux/security.h> |
1a980b8c MZ |
14 | #include <linux/mm.h> |
15 | #include <linux/fs.h> | |
d1d04ef8 MS |
16 | #include "overlayfs.h" |
17 | ||
2406a307 JX |
18 | struct ovl_aio_req { |
19 | struct kiocb iocb; | |
9a254403 | 20 | refcount_t ref; |
2406a307 JX |
21 | struct kiocb *orig_iocb; |
22 | struct fd fd; | |
23 | }; | |
24 | ||
25 | static struct kmem_cache *ovl_aio_request_cachep; | |
26 | ||
8c444d2a VG |
27 | static char ovl_whatisit(struct inode *inode, struct inode *realinode) |
28 | { | |
29 | if (realinode != ovl_inode_upper(inode)) | |
30 | return 'l'; | |
31 | if (ovl_has_upperdata(inode)) | |
32 | return 'u'; | |
33 | else | |
34 | return 'm'; | |
35 | } | |
36 | ||
cdf5c9d1 | 37 | /* No atime modification nor notify on underlying */ |
81a33c1e AG |
38 | #define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY) |
39 | ||
8c444d2a | 40 | static struct file *ovl_open_realfile(const struct file *file, |
2d343087 | 41 | const struct path *realpath) |
d1d04ef8 | 42 | { |
1248ea4b | 43 | struct inode *realinode = d_inode(realpath->dentry); |
d1d04ef8 | 44 | struct inode *inode = file_inode(file); |
4609e1f1 | 45 | struct mnt_idmap *real_idmap; |
8423b3bd | 46 | struct user_namespace *real_mnt_userns; |
d1d04ef8 MS |
47 | struct file *realfile; |
48 | const struct cred *old_cred; | |
81a33c1e | 49 | int flags = file->f_flags | OVL_OPEN_FLAGS; |
05acefb4 MS |
50 | int acc_mode = ACC_MODE(flags); |
51 | int err; | |
52 | ||
53 | if (flags & O_APPEND) | |
54 | acc_mode |= MAY_APPEND; | |
d1d04ef8 MS |
55 | |
56 | old_cred = ovl_override_creds(inode->i_sb); | |
4609e1f1 CB |
57 | real_idmap = mnt_idmap(realpath->mnt); |
58 | real_mnt_userns = mnt_idmap_owner(real_idmap); | |
59 | err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode); | |
05acefb4 MS |
60 | if (err) { |
61 | realfile = ERR_PTR(err); | |
05acefb4 | 62 | } else { |
8423b3bd | 63 | if (!inode_owner_or_capable(real_mnt_userns, realinode)) |
b6650dab MS |
64 | flags &= ~O_NOATIME; |
65 | ||
05acefb4 MS |
66 | realfile = open_with_fake_path(&file->f_path, flags, realinode, |
67 | current_cred()); | |
68 | } | |
d1d04ef8 MS |
69 | revert_creds(old_cred); |
70 | ||
71 | pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n", | |
8c444d2a | 72 | file, file, ovl_whatisit(inode, realinode), file->f_flags, |
d1d04ef8 MS |
73 | realfile, IS_ERR(realfile) ? 0 : realfile->f_flags); |
74 | ||
75 | return realfile; | |
76 | } | |
77 | ||
2ef66b8a MS |
78 | #define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT) |
79 | ||
80 | static int ovl_change_flags(struct file *file, unsigned int flags) | |
81 | { | |
82 | struct inode *inode = file_inode(file); | |
83 | int err; | |
84 | ||
2ef66b8a MS |
85 | flags &= OVL_SETFL_MASK; |
86 | ||
87 | if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
88 | return -EPERM; | |
89 | ||
a2ad63da N |
90 | if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT)) |
91 | return -EINVAL; | |
2ef66b8a MS |
92 | |
93 | if (file->f_op->check_flags) { | |
94 | err = file->f_op->check_flags(flags); | |
95 | if (err) | |
96 | return err; | |
97 | } | |
98 | ||
99 | spin_lock(&file->f_lock); | |
100 | file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags; | |
456b59e7 | 101 | file->f_iocb_flags = iocb_flags(file); |
2ef66b8a MS |
102 | spin_unlock(&file->f_lock); |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
8c444d2a VG |
107 | static int ovl_real_fdget_meta(const struct file *file, struct fd *real, |
108 | bool allow_meta) | |
2ef66b8a | 109 | { |
1248ea4b AG |
110 | struct dentry *dentry = file_dentry(file); |
111 | struct path realpath; | |
2ef66b8a MS |
112 | |
113 | real->flags = 0; | |
114 | real->file = file->private_data; | |
115 | ||
8c444d2a | 116 | if (allow_meta) |
1248ea4b | 117 | ovl_path_real(dentry, &realpath); |
8c444d2a | 118 | else |
1248ea4b | 119 | ovl_path_realdata(dentry, &realpath); |
8c444d2a | 120 | |
2ef66b8a | 121 | /* Has it been copied up since we'd opened it? */ |
1248ea4b | 122 | if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) { |
2ef66b8a | 123 | real->flags = FDPUT_FPUT; |
1248ea4b | 124 | real->file = ovl_open_realfile(file, &realpath); |
2ef66b8a MS |
125 | |
126 | return PTR_ERR_OR_ZERO(real->file); | |
127 | } | |
128 | ||
129 | /* Did the flags change since open? */ | |
81a33c1e | 130 | if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS)) |
2ef66b8a MS |
131 | return ovl_change_flags(real->file, file->f_flags); |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
8c444d2a VG |
136 | static int ovl_real_fdget(const struct file *file, struct fd *real) |
137 | { | |
61536bed AG |
138 | if (d_is_dir(file_dentry(file))) { |
139 | real->flags = 0; | |
140 | real->file = ovl_dir_real_file(file, false); | |
141 | ||
142 | return PTR_ERR_OR_ZERO(real->file); | |
143 | } | |
144 | ||
8c444d2a VG |
145 | return ovl_real_fdget_meta(file, real, false); |
146 | } | |
147 | ||
d1d04ef8 MS |
148 | static int ovl_open(struct inode *inode, struct file *file) |
149 | { | |
1248ea4b | 150 | struct dentry *dentry = file_dentry(file); |
d1d04ef8 | 151 | struct file *realfile; |
1248ea4b | 152 | struct path realpath; |
d1d04ef8 MS |
153 | int err; |
154 | ||
1248ea4b | 155 | err = ovl_maybe_copy_up(dentry, file->f_flags); |
d1d04ef8 MS |
156 | if (err) |
157 | return err; | |
158 | ||
159 | /* No longer need these flags, so don't pass them on to underlying fs */ | |
160 | file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); | |
161 | ||
1248ea4b AG |
162 | ovl_path_realdata(dentry, &realpath); |
163 | realfile = ovl_open_realfile(file, &realpath); | |
d1d04ef8 MS |
164 | if (IS_ERR(realfile)) |
165 | return PTR_ERR(realfile); | |
166 | ||
167 | file->private_data = realfile; | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | static int ovl_release(struct inode *inode, struct file *file) | |
173 | { | |
174 | fput(file->private_data); | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) | |
180 | { | |
9e46b840 AG |
181 | struct inode *inode = file_inode(file); |
182 | struct fd real; | |
183 | const struct cred *old_cred; | |
a4ac9d45 | 184 | loff_t ret; |
9e46b840 AG |
185 | |
186 | /* | |
187 | * The two special cases below do not need to involve real fs, | |
188 | * so we can optimizing concurrent callers. | |
189 | */ | |
190 | if (offset == 0) { | |
191 | if (whence == SEEK_CUR) | |
192 | return file->f_pos; | |
193 | ||
194 | if (whence == SEEK_SET) | |
195 | return vfs_setpos(file, 0, 0); | |
196 | } | |
197 | ||
198 | ret = ovl_real_fdget(file, &real); | |
199 | if (ret) | |
200 | return ret; | |
201 | ||
202 | /* | |
203 | * Overlay file f_pos is the master copy that is preserved | |
204 | * through copy up and modified on read/write, but only real | |
205 | * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose | |
206 | * limitations that are more strict than ->s_maxbytes for specific | |
207 | * files, so we use the real file to perform seeks. | |
208 | */ | |
b1f9d385 | 209 | ovl_inode_lock(inode); |
9e46b840 AG |
210 | real.file->f_pos = file->f_pos; |
211 | ||
212 | old_cred = ovl_override_creds(inode->i_sb); | |
213 | ret = vfs_llseek(real.file, offset, whence); | |
214 | revert_creds(old_cred); | |
215 | ||
216 | file->f_pos = real.file->f_pos; | |
b1f9d385 | 217 | ovl_inode_unlock(inode); |
9e46b840 AG |
218 | |
219 | fdput(real); | |
d1d04ef8 | 220 | |
9e46b840 | 221 | return ret; |
d1d04ef8 MS |
222 | } |
223 | ||
16914e6f MS |
224 | static void ovl_file_accessed(struct file *file) |
225 | { | |
226 | struct inode *inode, *upperinode; | |
227 | ||
228 | if (file->f_flags & O_NOATIME) | |
229 | return; | |
230 | ||
231 | inode = file_inode(file); | |
232 | upperinode = ovl_inode_upper(inode); | |
233 | ||
234 | if (!upperinode) | |
235 | return; | |
236 | ||
237 | if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) || | |
238 | !timespec64_equal(&inode->i_ctime, &upperinode->i_ctime))) { | |
239 | inode->i_mtime = upperinode->i_mtime; | |
240 | inode->i_ctime = upperinode->i_ctime; | |
241 | } | |
242 | ||
243 | touch_atime(&file->f_path); | |
244 | } | |
245 | ||
b778e1ee | 246 | static rwf_t ovl_iocb_to_rwf(int ifl) |
16914e6f | 247 | { |
16914e6f MS |
248 | rwf_t flags = 0; |
249 | ||
250 | if (ifl & IOCB_NOWAIT) | |
251 | flags |= RWF_NOWAIT; | |
252 | if (ifl & IOCB_HIPRI) | |
253 | flags |= RWF_HIPRI; | |
254 | if (ifl & IOCB_DSYNC) | |
255 | flags |= RWF_DSYNC; | |
256 | if (ifl & IOCB_SYNC) | |
257 | flags |= RWF_SYNC; | |
258 | ||
259 | return flags; | |
260 | } | |
261 | ||
9a254403 | 262 | static inline void ovl_aio_put(struct ovl_aio_req *aio_req) |
263 | { | |
264 | if (refcount_dec_and_test(&aio_req->ref)) { | |
265 | fdput(aio_req->fd); | |
266 | kmem_cache_free(ovl_aio_request_cachep, aio_req); | |
267 | } | |
268 | } | |
269 | ||
2406a307 JX |
270 | static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req) |
271 | { | |
272 | struct kiocb *iocb = &aio_req->iocb; | |
273 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
274 | ||
275 | if (iocb->ki_flags & IOCB_WRITE) { | |
276 | struct inode *inode = file_inode(orig_iocb->ki_filp); | |
277 | ||
c8536804 MS |
278 | /* Actually acquired in ovl_write_iter() */ |
279 | __sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb, | |
280 | SB_FREEZE_WRITE); | |
2406a307 | 281 | file_end_write(iocb->ki_filp); |
2878dffc | 282 | ovl_copyattr(inode); |
2406a307 JX |
283 | } |
284 | ||
285 | orig_iocb->ki_pos = iocb->ki_pos; | |
9a254403 | 286 | ovl_aio_put(aio_req); |
2406a307 JX |
287 | } |
288 | ||
6b19b766 | 289 | static void ovl_aio_rw_complete(struct kiocb *iocb, long res) |
2406a307 JX |
290 | { |
291 | struct ovl_aio_req *aio_req = container_of(iocb, | |
292 | struct ovl_aio_req, iocb); | |
293 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
294 | ||
295 | ovl_aio_cleanup_handler(aio_req); | |
6b19b766 | 296 | orig_iocb->ki_complete(orig_iocb, res); |
2406a307 JX |
297 | } |
298 | ||
16914e6f MS |
299 | static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
300 | { | |
301 | struct file *file = iocb->ki_filp; | |
302 | struct fd real; | |
303 | const struct cred *old_cred; | |
304 | ssize_t ret; | |
305 | ||
306 | if (!iov_iter_count(iter)) | |
307 | return 0; | |
308 | ||
309 | ret = ovl_real_fdget(file, &real); | |
310 | if (ret) | |
311 | return ret; | |
312 | ||
1dc1eed4 MS |
313 | ret = -EINVAL; |
314 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 315 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
316 | goto out_fdput; |
317 | ||
16914e6f | 318 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 JX |
319 | if (is_sync_kiocb(iocb)) { |
320 | ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, | |
b778e1ee | 321 | ovl_iocb_to_rwf(iocb->ki_flags)); |
2406a307 JX |
322 | } else { |
323 | struct ovl_aio_req *aio_req; | |
324 | ||
325 | ret = -ENOMEM; | |
326 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
327 | if (!aio_req) | |
328 | goto out; | |
329 | ||
330 | aio_req->fd = real; | |
331 | real.flags = 0; | |
332 | aio_req->orig_iocb = iocb; | |
333 | kiocb_clone(&aio_req->iocb, iocb, real.file); | |
334 | aio_req->iocb.ki_complete = ovl_aio_rw_complete; | |
9a254403 | 335 | refcount_set(&aio_req->ref, 2); |
2406a307 | 336 | ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter); |
9a254403 | 337 | ovl_aio_put(aio_req); |
2406a307 JX |
338 | if (ret != -EIOCBQUEUED) |
339 | ovl_aio_cleanup_handler(aio_req); | |
340 | } | |
341 | out: | |
16914e6f | 342 | revert_creds(old_cred); |
16914e6f | 343 | ovl_file_accessed(file); |
1dc1eed4 | 344 | out_fdput: |
16914e6f MS |
345 | fdput(real); |
346 | ||
347 | return ret; | |
348 | } | |
349 | ||
2a92e07e MS |
350 | static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) |
351 | { | |
352 | struct file *file = iocb->ki_filp; | |
353 | struct inode *inode = file_inode(file); | |
354 | struct fd real; | |
355 | const struct cred *old_cred; | |
356 | ssize_t ret; | |
c86243b0 | 357 | int ifl = iocb->ki_flags; |
2a92e07e MS |
358 | |
359 | if (!iov_iter_count(iter)) | |
360 | return 0; | |
361 | ||
362 | inode_lock(inode); | |
363 | /* Update mode */ | |
2878dffc | 364 | ovl_copyattr(inode); |
2a92e07e MS |
365 | ret = file_remove_privs(file); |
366 | if (ret) | |
367 | goto out_unlock; | |
368 | ||
369 | ret = ovl_real_fdget(file, &real); | |
370 | if (ret) | |
371 | goto out_unlock; | |
372 | ||
1dc1eed4 MS |
373 | ret = -EINVAL; |
374 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 375 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
376 | goto out_fdput; |
377 | ||
c86243b0 VG |
378 | if (!ovl_should_sync(OVL_FS(inode->i_sb))) |
379 | ifl &= ~(IOCB_DSYNC | IOCB_SYNC); | |
380 | ||
2a92e07e | 381 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 JX |
382 | if (is_sync_kiocb(iocb)) { |
383 | file_start_write(real.file); | |
384 | ret = vfs_iter_write(real.file, iter, &iocb->ki_pos, | |
c86243b0 | 385 | ovl_iocb_to_rwf(ifl)); |
2406a307 JX |
386 | file_end_write(real.file); |
387 | /* Update size */ | |
2878dffc | 388 | ovl_copyattr(inode); |
2406a307 JX |
389 | } else { |
390 | struct ovl_aio_req *aio_req; | |
391 | ||
392 | ret = -ENOMEM; | |
393 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
394 | if (!aio_req) | |
395 | goto out; | |
396 | ||
397 | file_start_write(real.file); | |
c8536804 MS |
398 | /* Pacify lockdep, same trick as done in aio_write() */ |
399 | __sb_writers_release(file_inode(real.file)->i_sb, | |
400 | SB_FREEZE_WRITE); | |
2406a307 JX |
401 | aio_req->fd = real; |
402 | real.flags = 0; | |
403 | aio_req->orig_iocb = iocb; | |
404 | kiocb_clone(&aio_req->iocb, iocb, real.file); | |
c86243b0 | 405 | aio_req->iocb.ki_flags = ifl; |
2406a307 | 406 | aio_req->iocb.ki_complete = ovl_aio_rw_complete; |
9a254403 | 407 | refcount_set(&aio_req->ref, 2); |
2406a307 | 408 | ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter); |
9a254403 | 409 | ovl_aio_put(aio_req); |
2406a307 JX |
410 | if (ret != -EIOCBQUEUED) |
411 | ovl_aio_cleanup_handler(aio_req); | |
412 | } | |
413 | out: | |
2a92e07e | 414 | revert_creds(old_cred); |
1dc1eed4 | 415 | out_fdput: |
2a92e07e MS |
416 | fdput(real); |
417 | ||
418 | out_unlock: | |
419 | inode_unlock(inode); | |
420 | ||
421 | return ret; | |
422 | } | |
423 | ||
9b91b6b0 MS |
424 | /* |
425 | * Calling iter_file_splice_write() directly from overlay's f_op may deadlock | |
426 | * due to lock order inversion between pipe->mutex in iter_file_splice_write() | |
427 | * and file_start_write(real.file) in ovl_write_iter(). | |
428 | * | |
429 | * So do everything ovl_write_iter() does and call iter_file_splice_write() on | |
430 | * the real file. | |
431 | */ | |
432 | static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out, | |
433 | loff_t *ppos, size_t len, unsigned int flags) | |
434 | { | |
435 | struct fd real; | |
436 | const struct cred *old_cred; | |
437 | struct inode *inode = file_inode(out); | |
9b91b6b0 MS |
438 | ssize_t ret; |
439 | ||
440 | inode_lock(inode); | |
441 | /* Update mode */ | |
2878dffc | 442 | ovl_copyattr(inode); |
9b91b6b0 MS |
443 | ret = file_remove_privs(out); |
444 | if (ret) | |
445 | goto out_unlock; | |
446 | ||
447 | ret = ovl_real_fdget(out, &real); | |
448 | if (ret) | |
449 | goto out_unlock; | |
450 | ||
451 | old_cred = ovl_override_creds(inode->i_sb); | |
452 | file_start_write(real.file); | |
453 | ||
454 | ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); | |
455 | ||
456 | file_end_write(real.file); | |
457 | /* Update size */ | |
2878dffc | 458 | ovl_copyattr(inode); |
9b91b6b0 MS |
459 | revert_creds(old_cred); |
460 | fdput(real); | |
461 | ||
462 | out_unlock: | |
463 | inode_unlock(inode); | |
464 | ||
465 | return ret; | |
466 | } | |
467 | ||
de30dfd6 MS |
468 | static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
469 | { | |
470 | struct fd real; | |
471 | const struct cred *old_cred; | |
472 | int ret; | |
473 | ||
335d3fc5 SD |
474 | ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb)); |
475 | if (ret <= 0) | |
476 | return ret; | |
c86243b0 | 477 | |
8c444d2a | 478 | ret = ovl_real_fdget_meta(file, &real, !datasync); |
de30dfd6 MS |
479 | if (ret) |
480 | return ret; | |
481 | ||
482 | /* Don't sync lower file for fear of receiving EROFS error */ | |
483 | if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) { | |
484 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
485 | ret = vfs_fsync_range(real.file, start, end, datasync); | |
486 | revert_creds(old_cred); | |
487 | } | |
488 | ||
489 | fdput(real); | |
490 | ||
491 | return ret; | |
492 | } | |
493 | ||
2f502839 MS |
494 | static int ovl_mmap(struct file *file, struct vm_area_struct *vma) |
495 | { | |
496 | struct file *realfile = file->private_data; | |
497 | const struct cred *old_cred; | |
498 | int ret; | |
499 | ||
500 | if (!realfile->f_op->mmap) | |
501 | return -ENODEV; | |
502 | ||
503 | if (WARN_ON(file != vma->vm_file)) | |
504 | return -EIO; | |
505 | ||
2896900e | 506 | vma_set_file(vma, realfile); |
2f502839 MS |
507 | |
508 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
509 | ret = call_mmap(vma->vm_file, vma); | |
510 | revert_creds(old_cred); | |
2f502839 MS |
511 | ovl_file_accessed(file); |
512 | ||
513 | return ret; | |
514 | } | |
515 | ||
aab8848c MS |
516 | static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
517 | { | |
518 | struct inode *inode = file_inode(file); | |
519 | struct fd real; | |
520 | const struct cred *old_cred; | |
521 | int ret; | |
522 | ||
23a8ce16 AG |
523 | inode_lock(inode); |
524 | /* Update mode */ | |
525 | ovl_copyattr(inode); | |
526 | ret = file_remove_privs(file); | |
527 | if (ret) | |
528 | goto out_unlock; | |
529 | ||
aab8848c MS |
530 | ret = ovl_real_fdget(file, &real); |
531 | if (ret) | |
23a8ce16 | 532 | goto out_unlock; |
aab8848c MS |
533 | |
534 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
535 | ret = vfs_fallocate(real.file, mode, offset, len); | |
536 | revert_creds(old_cred); | |
537 | ||
538 | /* Update size */ | |
2878dffc | 539 | ovl_copyattr(inode); |
aab8848c MS |
540 | |
541 | fdput(real); | |
542 | ||
23a8ce16 AG |
543 | out_unlock: |
544 | inode_unlock(inode); | |
545 | ||
aab8848c MS |
546 | return ret; |
547 | } | |
548 | ||
b833a366 AG |
549 | static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice) |
550 | { | |
551 | struct fd real; | |
552 | const struct cred *old_cred; | |
553 | int ret; | |
554 | ||
555 | ret = ovl_real_fdget(file, &real); | |
556 | if (ret) | |
557 | return ret; | |
558 | ||
559 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
560 | ret = vfs_fadvise(real.file, offset, len, advice); | |
561 | revert_creds(old_cred); | |
562 | ||
563 | fdput(real); | |
564 | ||
565 | return ret; | |
566 | } | |
567 | ||
8ede2055 MS |
568 | enum ovl_copyop { |
569 | OVL_COPY, | |
570 | OVL_CLONE, | |
571 | OVL_DEDUPE, | |
572 | }; | |
573 | ||
42ec3d4c | 574 | static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in, |
8ede2055 | 575 | struct file *file_out, loff_t pos_out, |
42ec3d4c | 576 | loff_t len, unsigned int flags, enum ovl_copyop op) |
8ede2055 MS |
577 | { |
578 | struct inode *inode_out = file_inode(file_out); | |
579 | struct fd real_in, real_out; | |
580 | const struct cred *old_cred; | |
42ec3d4c | 581 | loff_t ret; |
8ede2055 | 582 | |
b306e90f AG |
583 | inode_lock(inode_out); |
584 | if (op != OVL_DEDUPE) { | |
585 | /* Update mode */ | |
586 | ovl_copyattr(inode_out); | |
587 | ret = file_remove_privs(file_out); | |
588 | if (ret) | |
589 | goto out_unlock; | |
590 | } | |
591 | ||
8ede2055 MS |
592 | ret = ovl_real_fdget(file_out, &real_out); |
593 | if (ret) | |
b306e90f | 594 | goto out_unlock; |
8ede2055 MS |
595 | |
596 | ret = ovl_real_fdget(file_in, &real_in); | |
597 | if (ret) { | |
598 | fdput(real_out); | |
b306e90f | 599 | goto out_unlock; |
8ede2055 MS |
600 | } |
601 | ||
602 | old_cred = ovl_override_creds(file_inode(file_out)->i_sb); | |
603 | switch (op) { | |
604 | case OVL_COPY: | |
605 | ret = vfs_copy_file_range(real_in.file, pos_in, | |
606 | real_out.file, pos_out, len, flags); | |
607 | break; | |
608 | ||
609 | case OVL_CLONE: | |
a725356b | 610 | ret = vfs_clone_file_range(real_in.file, pos_in, |
452ce659 | 611 | real_out.file, pos_out, len, flags); |
8ede2055 MS |
612 | break; |
613 | ||
614 | case OVL_DEDUPE: | |
615 | ret = vfs_dedupe_file_range_one(real_in.file, pos_in, | |
df365836 DW |
616 | real_out.file, pos_out, len, |
617 | flags); | |
8ede2055 MS |
618 | break; |
619 | } | |
620 | revert_creds(old_cred); | |
621 | ||
622 | /* Update size */ | |
2878dffc | 623 | ovl_copyattr(inode_out); |
8ede2055 MS |
624 | |
625 | fdput(real_in); | |
626 | fdput(real_out); | |
627 | ||
b306e90f AG |
628 | out_unlock: |
629 | inode_unlock(inode_out); | |
630 | ||
8ede2055 MS |
631 | return ret; |
632 | } | |
633 | ||
634 | static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in, | |
635 | struct file *file_out, loff_t pos_out, | |
636 | size_t len, unsigned int flags) | |
637 | { | |
638 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags, | |
639 | OVL_COPY); | |
640 | } | |
641 | ||
42ec3d4c DW |
642 | static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in, |
643 | struct file *file_out, loff_t pos_out, | |
644 | loff_t len, unsigned int remap_flags) | |
8ede2055 | 645 | { |
2e5dfc99 DW |
646 | enum ovl_copyop op; |
647 | ||
648 | if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) | |
649 | return -EINVAL; | |
650 | ||
651 | if (remap_flags & REMAP_FILE_DEDUP) | |
652 | op = OVL_DEDUPE; | |
653 | else | |
654 | op = OVL_CLONE; | |
8ede2055 | 655 | |
8ede2055 MS |
656 | /* |
657 | * Don't copy up because of a dedupe request, this wouldn't make sense | |
658 | * most of the time (data would be duplicated instead of deduplicated). | |
659 | */ | |
2e5dfc99 DW |
660 | if (op == OVL_DEDUPE && |
661 | (!ovl_inode_upper(file_inode(file_in)) || | |
662 | !ovl_inode_upper(file_inode(file_out)))) | |
8ede2055 MS |
663 | return -EPERM; |
664 | ||
452ce659 DW |
665 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, |
666 | remap_flags, op); | |
8ede2055 MS |
667 | } |
668 | ||
1f0cb8bc SD |
669 | static int ovl_flush(struct file *file, fl_owner_t id) |
670 | { | |
671 | struct fd real; | |
672 | const struct cred *old_cred; | |
673 | int err; | |
674 | ||
675 | err = ovl_real_fdget(file, &real); | |
676 | if (err) | |
677 | return err; | |
678 | ||
679 | if (real.file->f_op->flush) { | |
680 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
681 | err = real.file->f_op->flush(real.file, id); | |
682 | revert_creds(old_cred); | |
683 | } | |
684 | fdput(real); | |
685 | ||
686 | return err; | |
687 | } | |
688 | ||
d1d04ef8 MS |
689 | const struct file_operations ovl_file_operations = { |
690 | .open = ovl_open, | |
691 | .release = ovl_release, | |
692 | .llseek = ovl_llseek, | |
16914e6f | 693 | .read_iter = ovl_read_iter, |
2a92e07e | 694 | .write_iter = ovl_write_iter, |
de30dfd6 | 695 | .fsync = ovl_fsync, |
2f502839 | 696 | .mmap = ovl_mmap, |
aab8848c | 697 | .fallocate = ovl_fallocate, |
b833a366 | 698 | .fadvise = ovl_fadvise, |
1f0cb8bc | 699 | .flush = ovl_flush, |
82a763e6 | 700 | .splice_read = generic_file_splice_read, |
9b91b6b0 | 701 | .splice_write = ovl_splice_write, |
8ede2055 MS |
702 | |
703 | .copy_file_range = ovl_copy_file_range, | |
2e5dfc99 | 704 | .remap_file_range = ovl_remap_file_range, |
d1d04ef8 | 705 | }; |
2406a307 JX |
706 | |
707 | int __init ovl_aio_request_cache_init(void) | |
708 | { | |
709 | ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req", | |
710 | sizeof(struct ovl_aio_req), | |
711 | 0, SLAB_HWCACHE_ALIGN, NULL); | |
712 | if (!ovl_aio_request_cachep) | |
713 | return -ENOMEM; | |
714 | ||
715 | return 0; | |
716 | } | |
717 | ||
718 | void ovl_aio_request_cache_destroy(void) | |
719 | { | |
720 | kmem_cache_destroy(ovl_aio_request_cachep); | |
721 | } |