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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 | ||
389a4a4a AG |
18 | #include "../internal.h" /* for sb_init_dio_done_wq */ |
19 | ||
2406a307 JX |
20 | struct ovl_aio_req { |
21 | struct kiocb iocb; | |
9a254403 | 22 | refcount_t ref; |
2406a307 | 23 | struct kiocb *orig_iocb; |
389a4a4a AG |
24 | /* used for aio completion */ |
25 | struct work_struct work; | |
26 | long res; | |
2406a307 JX |
27 | }; |
28 | ||
29 | static struct kmem_cache *ovl_aio_request_cachep; | |
30 | ||
8c444d2a VG |
31 | static char ovl_whatisit(struct inode *inode, struct inode *realinode) |
32 | { | |
33 | if (realinode != ovl_inode_upper(inode)) | |
34 | return 'l'; | |
35 | if (ovl_has_upperdata(inode)) | |
36 | return 'u'; | |
37 | else | |
38 | return 'm'; | |
39 | } | |
40 | ||
bc2473c9 AG |
41 | /* No atime modification on underlying */ |
42 | #define OVL_OPEN_FLAGS (O_NOATIME) | |
81a33c1e | 43 | |
8c444d2a | 44 | static struct file *ovl_open_realfile(const struct file *file, |
2d343087 | 45 | const struct path *realpath) |
d1d04ef8 | 46 | { |
1248ea4b | 47 | struct inode *realinode = d_inode(realpath->dentry); |
d1d04ef8 | 48 | struct inode *inode = file_inode(file); |
4609e1f1 | 49 | struct mnt_idmap *real_idmap; |
d1d04ef8 MS |
50 | struct file *realfile; |
51 | const struct cred *old_cred; | |
81a33c1e | 52 | int flags = file->f_flags | OVL_OPEN_FLAGS; |
05acefb4 MS |
53 | int acc_mode = ACC_MODE(flags); |
54 | int err; | |
55 | ||
56 | if (flags & O_APPEND) | |
57 | acc_mode |= MAY_APPEND; | |
d1d04ef8 MS |
58 | |
59 | old_cred = ovl_override_creds(inode->i_sb); | |
4609e1f1 | 60 | real_idmap = mnt_idmap(realpath->mnt); |
4609e1f1 | 61 | err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode); |
05acefb4 MS |
62 | if (err) { |
63 | realfile = ERR_PTR(err); | |
05acefb4 | 64 | } else { |
01beba79 | 65 | if (!inode_owner_or_capable(real_idmap, realinode)) |
b6650dab MS |
66 | flags &= ~O_NOATIME; |
67 | ||
62d53c4a AG |
68 | realfile = backing_file_open(&file->f_path, flags, realpath, |
69 | current_cred()); | |
05acefb4 | 70 | } |
d1d04ef8 MS |
71 | revert_creds(old_cred); |
72 | ||
73 | pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n", | |
8c444d2a | 74 | file, file, ovl_whatisit(inode, realinode), file->f_flags, |
d1d04ef8 MS |
75 | realfile, IS_ERR(realfile) ? 0 : realfile->f_flags); |
76 | ||
77 | return realfile; | |
78 | } | |
79 | ||
2ef66b8a MS |
80 | #define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT) |
81 | ||
82 | static int ovl_change_flags(struct file *file, unsigned int flags) | |
83 | { | |
84 | struct inode *inode = file_inode(file); | |
85 | int err; | |
86 | ||
2ef66b8a MS |
87 | flags &= OVL_SETFL_MASK; |
88 | ||
89 | if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
90 | return -EPERM; | |
91 | ||
a2ad63da N |
92 | if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT)) |
93 | return -EINVAL; | |
2ef66b8a MS |
94 | |
95 | if (file->f_op->check_flags) { | |
96 | err = file->f_op->check_flags(flags); | |
97 | if (err) | |
98 | return err; | |
99 | } | |
100 | ||
101 | spin_lock(&file->f_lock); | |
102 | file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags; | |
456b59e7 | 103 | file->f_iocb_flags = iocb_flags(file); |
2ef66b8a MS |
104 | spin_unlock(&file->f_lock); |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
8c444d2a VG |
109 | static int ovl_real_fdget_meta(const struct file *file, struct fd *real, |
110 | bool allow_meta) | |
2ef66b8a | 111 | { |
1248ea4b AG |
112 | struct dentry *dentry = file_dentry(file); |
113 | struct path realpath; | |
42dd69ae | 114 | int err; |
2ef66b8a MS |
115 | |
116 | real->flags = 0; | |
117 | real->file = file->private_data; | |
118 | ||
42dd69ae | 119 | if (allow_meta) { |
1248ea4b | 120 | ovl_path_real(dentry, &realpath); |
42dd69ae | 121 | } else { |
184996e9 AL |
122 | /* lazy lookup and verify of lowerdata */ |
123 | err = ovl_verify_lowerdata(dentry); | |
42dd69ae AG |
124 | if (err) |
125 | return err; | |
126 | ||
1248ea4b | 127 | ovl_path_realdata(dentry, &realpath); |
42dd69ae | 128 | } |
41665644 AG |
129 | if (!realpath.dentry) |
130 | return -EIO; | |
8c444d2a | 131 | |
2ef66b8a | 132 | /* Has it been copied up since we'd opened it? */ |
1248ea4b | 133 | if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) { |
2ef66b8a | 134 | real->flags = FDPUT_FPUT; |
1248ea4b | 135 | real->file = ovl_open_realfile(file, &realpath); |
2ef66b8a MS |
136 | |
137 | return PTR_ERR_OR_ZERO(real->file); | |
138 | } | |
139 | ||
140 | /* Did the flags change since open? */ | |
81a33c1e | 141 | if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS)) |
2ef66b8a MS |
142 | return ovl_change_flags(real->file, file->f_flags); |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
8c444d2a VG |
147 | static int ovl_real_fdget(const struct file *file, struct fd *real) |
148 | { | |
61536bed AG |
149 | if (d_is_dir(file_dentry(file))) { |
150 | real->flags = 0; | |
151 | real->file = ovl_dir_real_file(file, false); | |
152 | ||
153 | return PTR_ERR_OR_ZERO(real->file); | |
154 | } | |
155 | ||
8c444d2a VG |
156 | return ovl_real_fdget_meta(file, real, false); |
157 | } | |
158 | ||
d1d04ef8 MS |
159 | static int ovl_open(struct inode *inode, struct file *file) |
160 | { | |
1248ea4b | 161 | struct dentry *dentry = file_dentry(file); |
d1d04ef8 | 162 | struct file *realfile; |
1248ea4b | 163 | struct path realpath; |
d1d04ef8 MS |
164 | int err; |
165 | ||
184996e9 AL |
166 | /* lazy lookup and verify lowerdata */ |
167 | err = ovl_verify_lowerdata(dentry); | |
42dd69ae AG |
168 | if (err) |
169 | return err; | |
170 | ||
1248ea4b | 171 | err = ovl_maybe_copy_up(dentry, file->f_flags); |
d1d04ef8 MS |
172 | if (err) |
173 | return err; | |
174 | ||
175 | /* No longer need these flags, so don't pass them on to underlying fs */ | |
176 | file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); | |
177 | ||
1248ea4b | 178 | ovl_path_realdata(dentry, &realpath); |
41665644 AG |
179 | if (!realpath.dentry) |
180 | return -EIO; | |
181 | ||
1248ea4b | 182 | realfile = ovl_open_realfile(file, &realpath); |
d1d04ef8 MS |
183 | if (IS_ERR(realfile)) |
184 | return PTR_ERR(realfile); | |
185 | ||
186 | file->private_data = realfile; | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | static int ovl_release(struct inode *inode, struct file *file) | |
192 | { | |
193 | fput(file->private_data); | |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
198 | static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) | |
199 | { | |
9e46b840 AG |
200 | struct inode *inode = file_inode(file); |
201 | struct fd real; | |
202 | const struct cred *old_cred; | |
a4ac9d45 | 203 | loff_t ret; |
9e46b840 AG |
204 | |
205 | /* | |
206 | * The two special cases below do not need to involve real fs, | |
207 | * so we can optimizing concurrent callers. | |
208 | */ | |
209 | if (offset == 0) { | |
210 | if (whence == SEEK_CUR) | |
211 | return file->f_pos; | |
212 | ||
213 | if (whence == SEEK_SET) | |
214 | return vfs_setpos(file, 0, 0); | |
215 | } | |
216 | ||
217 | ret = ovl_real_fdget(file, &real); | |
218 | if (ret) | |
219 | return ret; | |
220 | ||
221 | /* | |
222 | * Overlay file f_pos is the master copy that is preserved | |
223 | * through copy up and modified on read/write, but only real | |
224 | * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose | |
225 | * limitations that are more strict than ->s_maxbytes for specific | |
226 | * files, so we use the real file to perform seeks. | |
227 | */ | |
b1f9d385 | 228 | ovl_inode_lock(inode); |
9e46b840 AG |
229 | real.file->f_pos = file->f_pos; |
230 | ||
231 | old_cred = ovl_override_creds(inode->i_sb); | |
232 | ret = vfs_llseek(real.file, offset, whence); | |
233 | revert_creds(old_cred); | |
234 | ||
235 | file->f_pos = real.file->f_pos; | |
b1f9d385 | 236 | ovl_inode_unlock(inode); |
9e46b840 AG |
237 | |
238 | fdput(real); | |
d1d04ef8 | 239 | |
9e46b840 | 240 | return ret; |
d1d04ef8 MS |
241 | } |
242 | ||
c002728f AG |
243 | static void ovl_file_modified(struct file *file) |
244 | { | |
245 | /* Update size/mtime */ | |
246 | ovl_copyattr(file_inode(file)); | |
247 | } | |
248 | ||
16914e6f MS |
249 | static void ovl_file_accessed(struct file *file) |
250 | { | |
251 | struct inode *inode, *upperinode; | |
9aa71115 | 252 | struct timespec64 ctime, uctime; |
4ddbd0f1 | 253 | struct timespec64 mtime, umtime; |
16914e6f MS |
254 | |
255 | if (file->f_flags & O_NOATIME) | |
256 | return; | |
257 | ||
258 | inode = file_inode(file); | |
259 | upperinode = ovl_inode_upper(inode); | |
260 | ||
261 | if (!upperinode) | |
262 | return; | |
263 | ||
9aa71115 JL |
264 | ctime = inode_get_ctime(inode); |
265 | uctime = inode_get_ctime(upperinode); | |
4ddbd0f1 JL |
266 | mtime = inode_get_mtime(inode); |
267 | umtime = inode_get_mtime(upperinode); | |
268 | if ((!timespec64_equal(&mtime, &umtime)) || | |
269 | !timespec64_equal(&ctime, &uctime)) { | |
270 | inode_set_mtime_to_ts(inode, inode_get_mtime(upperinode)); | |
9aa71115 | 271 | inode_set_ctime_to_ts(inode, uctime); |
16914e6f MS |
272 | } |
273 | ||
274 | touch_atime(&file->f_path); | |
275 | } | |
276 | ||
db5b5e83 | 277 | #define OVL_IOCB_MASK \ |
5f034d34 | 278 | (IOCB_NOWAIT | IOCB_HIPRI | IOCB_DSYNC | IOCB_SYNC | IOCB_APPEND) |
db5b5e83 AG |
279 | |
280 | static rwf_t iocb_to_rw_flags(int flags) | |
16914e6f | 281 | { |
db5b5e83 | 282 | return (__force rwf_t)(flags & OVL_IOCB_MASK); |
16914e6f MS |
283 | } |
284 | ||
9a254403 | 285 | static inline void ovl_aio_put(struct ovl_aio_req *aio_req) |
286 | { | |
287 | if (refcount_dec_and_test(&aio_req->ref)) { | |
724768a3 | 288 | fput(aio_req->iocb.ki_filp); |
9a254403 | 289 | kmem_cache_free(ovl_aio_request_cachep, aio_req); |
290 | } | |
291 | } | |
292 | ||
2406a307 JX |
293 | static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req) |
294 | { | |
295 | struct kiocb *iocb = &aio_req->iocb; | |
296 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
297 | ||
298 | if (iocb->ki_flags & IOCB_WRITE) { | |
8f737126 | 299 | kiocb_end_write(iocb); |
c002728f | 300 | ovl_file_modified(orig_iocb->ki_filp); |
2406a307 JX |
301 | } |
302 | ||
303 | orig_iocb->ki_pos = iocb->ki_pos; | |
9a254403 | 304 | ovl_aio_put(aio_req); |
2406a307 JX |
305 | } |
306 | ||
6b19b766 | 307 | static void ovl_aio_rw_complete(struct kiocb *iocb, long res) |
2406a307 JX |
308 | { |
309 | struct ovl_aio_req *aio_req = container_of(iocb, | |
310 | struct ovl_aio_req, iocb); | |
311 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
312 | ||
313 | ovl_aio_cleanup_handler(aio_req); | |
6b19b766 | 314 | orig_iocb->ki_complete(orig_iocb, res); |
2406a307 JX |
315 | } |
316 | ||
389a4a4a AG |
317 | static void ovl_aio_complete_work(struct work_struct *work) |
318 | { | |
319 | struct ovl_aio_req *aio_req = container_of(work, | |
320 | struct ovl_aio_req, work); | |
321 | ||
322 | ovl_aio_rw_complete(&aio_req->iocb, aio_req->res); | |
323 | } | |
324 | ||
325 | static void ovl_aio_queue_completion(struct kiocb *iocb, long res) | |
326 | { | |
327 | struct ovl_aio_req *aio_req = container_of(iocb, | |
328 | struct ovl_aio_req, iocb); | |
329 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
330 | ||
331 | /* | |
332 | * Punt to a work queue to serialize updates of mtime/size. | |
333 | */ | |
334 | aio_req->res = res; | |
335 | INIT_WORK(&aio_req->work, ovl_aio_complete_work); | |
336 | queue_work(file_inode(orig_iocb->ki_filp)->i_sb->s_dio_done_wq, | |
337 | &aio_req->work); | |
338 | } | |
339 | ||
340 | static int ovl_init_aio_done_wq(struct super_block *sb) | |
341 | { | |
342 | if (sb->s_dio_done_wq) | |
343 | return 0; | |
344 | ||
345 | return sb_init_dio_done_wq(sb); | |
346 | } | |
347 | ||
16914e6f MS |
348 | static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
349 | { | |
350 | struct file *file = iocb->ki_filp; | |
351 | struct fd real; | |
352 | const struct cred *old_cred; | |
353 | ssize_t ret; | |
354 | ||
355 | if (!iov_iter_count(iter)) | |
356 | return 0; | |
357 | ||
358 | ret = ovl_real_fdget(file, &real); | |
359 | if (ret) | |
360 | return ret; | |
361 | ||
1dc1eed4 MS |
362 | ret = -EINVAL; |
363 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 364 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
365 | goto out_fdput; |
366 | ||
16914e6f | 367 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 | 368 | if (is_sync_kiocb(iocb)) { |
db5b5e83 AG |
369 | rwf_t rwf = iocb_to_rw_flags(iocb->ki_flags); |
370 | ||
371 | ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, rwf); | |
2406a307 JX |
372 | } else { |
373 | struct ovl_aio_req *aio_req; | |
374 | ||
375 | ret = -ENOMEM; | |
376 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
377 | if (!aio_req) | |
378 | goto out; | |
379 | ||
2406a307 | 380 | aio_req->orig_iocb = iocb; |
724768a3 | 381 | kiocb_clone(&aio_req->iocb, iocb, get_file(real.file)); |
2406a307 | 382 | aio_req->iocb.ki_complete = ovl_aio_rw_complete; |
9a254403 | 383 | refcount_set(&aio_req->ref, 2); |
2406a307 | 384 | ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter); |
9a254403 | 385 | ovl_aio_put(aio_req); |
2406a307 JX |
386 | if (ret != -EIOCBQUEUED) |
387 | ovl_aio_cleanup_handler(aio_req); | |
388 | } | |
389 | out: | |
16914e6f | 390 | revert_creds(old_cred); |
16914e6f | 391 | ovl_file_accessed(file); |
1dc1eed4 | 392 | out_fdput: |
16914e6f MS |
393 | fdput(real); |
394 | ||
395 | return ret; | |
396 | } | |
397 | ||
2a92e07e MS |
398 | static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) |
399 | { | |
400 | struct file *file = iocb->ki_filp; | |
401 | struct inode *inode = file_inode(file); | |
402 | struct fd real; | |
403 | const struct cred *old_cred; | |
404 | ssize_t ret; | |
c86243b0 | 405 | int ifl = iocb->ki_flags; |
2a92e07e MS |
406 | |
407 | if (!iov_iter_count(iter)) | |
408 | return 0; | |
409 | ||
410 | inode_lock(inode); | |
411 | /* Update mode */ | |
2878dffc | 412 | ovl_copyattr(inode); |
2a92e07e MS |
413 | ret = file_remove_privs(file); |
414 | if (ret) | |
415 | goto out_unlock; | |
416 | ||
417 | ret = ovl_real_fdget(file, &real); | |
418 | if (ret) | |
419 | goto out_unlock; | |
420 | ||
1dc1eed4 MS |
421 | ret = -EINVAL; |
422 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 423 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
424 | goto out_fdput; |
425 | ||
c86243b0 VG |
426 | if (!ovl_should_sync(OVL_FS(inode->i_sb))) |
427 | ifl &= ~(IOCB_DSYNC | IOCB_SYNC); | |
428 | ||
2d1b3bbc JA |
429 | /* |
430 | * Overlayfs doesn't support deferred completions, don't copy | |
431 | * this property in case it is set by the issuer. | |
432 | */ | |
433 | ifl &= ~IOCB_DIO_CALLER_COMP; | |
434 | ||
2a92e07e | 435 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 | 436 | if (is_sync_kiocb(iocb)) { |
db5b5e83 AG |
437 | rwf_t rwf = iocb_to_rw_flags(ifl); |
438 | ||
db5b5e83 | 439 | ret = vfs_iter_write(real.file, iter, &iocb->ki_pos, rwf); |
2406a307 | 440 | /* Update size */ |
c002728f | 441 | ovl_file_modified(file); |
2406a307 JX |
442 | } else { |
443 | struct ovl_aio_req *aio_req; | |
444 | ||
389a4a4a AG |
445 | ret = ovl_init_aio_done_wq(inode->i_sb); |
446 | if (ret) | |
447 | goto out; | |
448 | ||
2406a307 JX |
449 | ret = -ENOMEM; |
450 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
451 | if (!aio_req) | |
452 | goto out; | |
453 | ||
2406a307 | 454 | aio_req->orig_iocb = iocb; |
724768a3 | 455 | kiocb_clone(&aio_req->iocb, iocb, get_file(real.file)); |
c86243b0 | 456 | aio_req->iocb.ki_flags = ifl; |
389a4a4a | 457 | aio_req->iocb.ki_complete = ovl_aio_queue_completion; |
9a254403 | 458 | refcount_set(&aio_req->ref, 2); |
8f737126 | 459 | kiocb_start_write(&aio_req->iocb); |
2406a307 | 460 | ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter); |
9a254403 | 461 | ovl_aio_put(aio_req); |
2406a307 JX |
462 | if (ret != -EIOCBQUEUED) |
463 | ovl_aio_cleanup_handler(aio_req); | |
464 | } | |
465 | out: | |
2a92e07e | 466 | revert_creds(old_cred); |
1dc1eed4 | 467 | out_fdput: |
2a92e07e MS |
468 | fdput(real); |
469 | ||
470 | out_unlock: | |
471 | inode_unlock(inode); | |
472 | ||
473 | return ret; | |
474 | } | |
475 | ||
d4120d87 DH |
476 | static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, |
477 | struct pipe_inode_info *pipe, size_t len, | |
478 | unsigned int flags) | |
479 | { | |
480 | const struct cred *old_cred; | |
481 | struct fd real; | |
482 | ssize_t ret; | |
483 | ||
484 | ret = ovl_real_fdget(in, &real); | |
485 | if (ret) | |
486 | return ret; | |
487 | ||
488 | old_cred = ovl_override_creds(file_inode(in)->i_sb); | |
489 | ret = vfs_splice_read(real.file, ppos, pipe, len, flags); | |
490 | revert_creds(old_cred); | |
491 | ovl_file_accessed(in); | |
492 | ||
493 | fdput(real); | |
494 | return ret; | |
495 | } | |
496 | ||
9b91b6b0 MS |
497 | /* |
498 | * Calling iter_file_splice_write() directly from overlay's f_op may deadlock | |
499 | * due to lock order inversion between pipe->mutex in iter_file_splice_write() | |
500 | * and file_start_write(real.file) in ovl_write_iter(). | |
501 | * | |
502 | * So do everything ovl_write_iter() does and call iter_file_splice_write() on | |
503 | * the real file. | |
504 | */ | |
505 | static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out, | |
506 | loff_t *ppos, size_t len, unsigned int flags) | |
507 | { | |
508 | struct fd real; | |
509 | const struct cred *old_cred; | |
510 | struct inode *inode = file_inode(out); | |
9b91b6b0 MS |
511 | ssize_t ret; |
512 | ||
513 | inode_lock(inode); | |
514 | /* Update mode */ | |
2878dffc | 515 | ovl_copyattr(inode); |
9b91b6b0 MS |
516 | ret = file_remove_privs(out); |
517 | if (ret) | |
518 | goto out_unlock; | |
519 | ||
520 | ret = ovl_real_fdget(out, &real); | |
521 | if (ret) | |
522 | goto out_unlock; | |
523 | ||
524 | old_cred = ovl_override_creds(inode->i_sb); | |
525 | file_start_write(real.file); | |
526 | ||
527 | ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); | |
528 | ||
529 | file_end_write(real.file); | |
530 | /* Update size */ | |
c002728f | 531 | ovl_file_modified(out); |
9b91b6b0 MS |
532 | revert_creds(old_cred); |
533 | fdput(real); | |
534 | ||
535 | out_unlock: | |
536 | inode_unlock(inode); | |
537 | ||
538 | return ret; | |
539 | } | |
540 | ||
de30dfd6 MS |
541 | static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
542 | { | |
543 | struct fd real; | |
544 | const struct cred *old_cred; | |
545 | int ret; | |
546 | ||
335d3fc5 SD |
547 | ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb)); |
548 | if (ret <= 0) | |
549 | return ret; | |
c86243b0 | 550 | |
8c444d2a | 551 | ret = ovl_real_fdget_meta(file, &real, !datasync); |
de30dfd6 MS |
552 | if (ret) |
553 | return ret; | |
554 | ||
555 | /* Don't sync lower file for fear of receiving EROFS error */ | |
556 | if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) { | |
557 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
558 | ret = vfs_fsync_range(real.file, start, end, datasync); | |
559 | revert_creds(old_cred); | |
560 | } | |
561 | ||
562 | fdput(real); | |
563 | ||
564 | return ret; | |
565 | } | |
566 | ||
2f502839 MS |
567 | static int ovl_mmap(struct file *file, struct vm_area_struct *vma) |
568 | { | |
569 | struct file *realfile = file->private_data; | |
570 | const struct cred *old_cred; | |
571 | int ret; | |
572 | ||
573 | if (!realfile->f_op->mmap) | |
574 | return -ENODEV; | |
575 | ||
576 | if (WARN_ON(file != vma->vm_file)) | |
577 | return -EIO; | |
578 | ||
2896900e | 579 | vma_set_file(vma, realfile); |
2f502839 MS |
580 | |
581 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
582 | ret = call_mmap(vma->vm_file, vma); | |
583 | revert_creds(old_cred); | |
2f502839 MS |
584 | ovl_file_accessed(file); |
585 | ||
586 | return ret; | |
587 | } | |
588 | ||
aab8848c MS |
589 | static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
590 | { | |
591 | struct inode *inode = file_inode(file); | |
592 | struct fd real; | |
593 | const struct cred *old_cred; | |
594 | int ret; | |
595 | ||
23a8ce16 AG |
596 | inode_lock(inode); |
597 | /* Update mode */ | |
598 | ovl_copyattr(inode); | |
599 | ret = file_remove_privs(file); | |
600 | if (ret) | |
601 | goto out_unlock; | |
602 | ||
aab8848c MS |
603 | ret = ovl_real_fdget(file, &real); |
604 | if (ret) | |
23a8ce16 | 605 | goto out_unlock; |
aab8848c MS |
606 | |
607 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
608 | ret = vfs_fallocate(real.file, mode, offset, len); | |
609 | revert_creds(old_cred); | |
610 | ||
611 | /* Update size */ | |
c002728f | 612 | ovl_file_modified(file); |
aab8848c MS |
613 | |
614 | fdput(real); | |
615 | ||
23a8ce16 AG |
616 | out_unlock: |
617 | inode_unlock(inode); | |
618 | ||
aab8848c MS |
619 | return ret; |
620 | } | |
621 | ||
b833a366 AG |
622 | static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice) |
623 | { | |
624 | struct fd real; | |
625 | const struct cred *old_cred; | |
626 | int ret; | |
627 | ||
628 | ret = ovl_real_fdget(file, &real); | |
629 | if (ret) | |
630 | return ret; | |
631 | ||
632 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
633 | ret = vfs_fadvise(real.file, offset, len, advice); | |
634 | revert_creds(old_cred); | |
635 | ||
636 | fdput(real); | |
637 | ||
638 | return ret; | |
639 | } | |
640 | ||
8ede2055 MS |
641 | enum ovl_copyop { |
642 | OVL_COPY, | |
643 | OVL_CLONE, | |
644 | OVL_DEDUPE, | |
645 | }; | |
646 | ||
42ec3d4c | 647 | static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in, |
8ede2055 | 648 | struct file *file_out, loff_t pos_out, |
42ec3d4c | 649 | loff_t len, unsigned int flags, enum ovl_copyop op) |
8ede2055 MS |
650 | { |
651 | struct inode *inode_out = file_inode(file_out); | |
652 | struct fd real_in, real_out; | |
653 | const struct cred *old_cred; | |
42ec3d4c | 654 | loff_t ret; |
8ede2055 | 655 | |
b306e90f AG |
656 | inode_lock(inode_out); |
657 | if (op != OVL_DEDUPE) { | |
658 | /* Update mode */ | |
659 | ovl_copyattr(inode_out); | |
660 | ret = file_remove_privs(file_out); | |
661 | if (ret) | |
662 | goto out_unlock; | |
663 | } | |
664 | ||
8ede2055 MS |
665 | ret = ovl_real_fdget(file_out, &real_out); |
666 | if (ret) | |
b306e90f | 667 | goto out_unlock; |
8ede2055 MS |
668 | |
669 | ret = ovl_real_fdget(file_in, &real_in); | |
670 | if (ret) { | |
671 | fdput(real_out); | |
b306e90f | 672 | goto out_unlock; |
8ede2055 MS |
673 | } |
674 | ||
675 | old_cred = ovl_override_creds(file_inode(file_out)->i_sb); | |
676 | switch (op) { | |
677 | case OVL_COPY: | |
678 | ret = vfs_copy_file_range(real_in.file, pos_in, | |
679 | real_out.file, pos_out, len, flags); | |
680 | break; | |
681 | ||
682 | case OVL_CLONE: | |
a725356b | 683 | ret = vfs_clone_file_range(real_in.file, pos_in, |
452ce659 | 684 | real_out.file, pos_out, len, flags); |
8ede2055 MS |
685 | break; |
686 | ||
687 | case OVL_DEDUPE: | |
688 | ret = vfs_dedupe_file_range_one(real_in.file, pos_in, | |
df365836 DW |
689 | real_out.file, pos_out, len, |
690 | flags); | |
8ede2055 MS |
691 | break; |
692 | } | |
693 | revert_creds(old_cred); | |
694 | ||
695 | /* Update size */ | |
c002728f | 696 | ovl_file_modified(file_out); |
8ede2055 MS |
697 | |
698 | fdput(real_in); | |
699 | fdput(real_out); | |
700 | ||
b306e90f AG |
701 | out_unlock: |
702 | inode_unlock(inode_out); | |
703 | ||
8ede2055 MS |
704 | return ret; |
705 | } | |
706 | ||
707 | static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in, | |
708 | struct file *file_out, loff_t pos_out, | |
709 | size_t len, unsigned int flags) | |
710 | { | |
711 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags, | |
712 | OVL_COPY); | |
713 | } | |
714 | ||
42ec3d4c DW |
715 | static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in, |
716 | struct file *file_out, loff_t pos_out, | |
717 | loff_t len, unsigned int remap_flags) | |
8ede2055 | 718 | { |
2e5dfc99 DW |
719 | enum ovl_copyop op; |
720 | ||
721 | if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) | |
722 | return -EINVAL; | |
723 | ||
724 | if (remap_flags & REMAP_FILE_DEDUP) | |
725 | op = OVL_DEDUPE; | |
726 | else | |
727 | op = OVL_CLONE; | |
8ede2055 | 728 | |
8ede2055 MS |
729 | /* |
730 | * Don't copy up because of a dedupe request, this wouldn't make sense | |
731 | * most of the time (data would be duplicated instead of deduplicated). | |
732 | */ | |
2e5dfc99 DW |
733 | if (op == OVL_DEDUPE && |
734 | (!ovl_inode_upper(file_inode(file_in)) || | |
735 | !ovl_inode_upper(file_inode(file_out)))) | |
8ede2055 MS |
736 | return -EPERM; |
737 | ||
452ce659 DW |
738 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, |
739 | remap_flags, op); | |
8ede2055 MS |
740 | } |
741 | ||
1f0cb8bc SD |
742 | static int ovl_flush(struct file *file, fl_owner_t id) |
743 | { | |
744 | struct fd real; | |
745 | const struct cred *old_cred; | |
746 | int err; | |
747 | ||
748 | err = ovl_real_fdget(file, &real); | |
749 | if (err) | |
750 | return err; | |
751 | ||
752 | if (real.file->f_op->flush) { | |
753 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
754 | err = real.file->f_op->flush(real.file, id); | |
755 | revert_creds(old_cred); | |
756 | } | |
757 | fdput(real); | |
758 | ||
759 | return err; | |
760 | } | |
761 | ||
d1d04ef8 MS |
762 | const struct file_operations ovl_file_operations = { |
763 | .open = ovl_open, | |
764 | .release = ovl_release, | |
765 | .llseek = ovl_llseek, | |
16914e6f | 766 | .read_iter = ovl_read_iter, |
2a92e07e | 767 | .write_iter = ovl_write_iter, |
de30dfd6 | 768 | .fsync = ovl_fsync, |
2f502839 | 769 | .mmap = ovl_mmap, |
aab8848c | 770 | .fallocate = ovl_fallocate, |
b833a366 | 771 | .fadvise = ovl_fadvise, |
1f0cb8bc | 772 | .flush = ovl_flush, |
d4120d87 | 773 | .splice_read = ovl_splice_read, |
9b91b6b0 | 774 | .splice_write = ovl_splice_write, |
8ede2055 MS |
775 | |
776 | .copy_file_range = ovl_copy_file_range, | |
2e5dfc99 | 777 | .remap_file_range = ovl_remap_file_range, |
d1d04ef8 | 778 | }; |
2406a307 JX |
779 | |
780 | int __init ovl_aio_request_cache_init(void) | |
781 | { | |
782 | ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req", | |
783 | sizeof(struct ovl_aio_req), | |
784 | 0, SLAB_HWCACHE_ALIGN, NULL); | |
785 | if (!ovl_aio_request_cachep) | |
786 | return -ENOMEM; | |
787 | ||
788 | return 0; | |
789 | } | |
790 | ||
791 | void ovl_aio_request_cache_destroy(void) | |
792 | { | |
793 | kmem_cache_destroy(ovl_aio_request_cachep); | |
794 | } |