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