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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 | 21 | struct kiocb *orig_iocb; |
2406a307 JX |
22 | }; |
23 | ||
24 | static struct kmem_cache *ovl_aio_request_cachep; | |
25 | ||
8c444d2a VG |
26 | static char ovl_whatisit(struct inode *inode, struct inode *realinode) |
27 | { | |
28 | if (realinode != ovl_inode_upper(inode)) | |
29 | return 'l'; | |
30 | if (ovl_has_upperdata(inode)) | |
31 | return 'u'; | |
32 | else | |
33 | return 'm'; | |
34 | } | |
35 | ||
bc2473c9 AG |
36 | /* No atime modification on underlying */ |
37 | #define OVL_OPEN_FLAGS (O_NOATIME) | |
81a33c1e | 38 | |
8c444d2a | 39 | static struct file *ovl_open_realfile(const struct file *file, |
2d343087 | 40 | const struct path *realpath) |
d1d04ef8 | 41 | { |
1248ea4b | 42 | struct inode *realinode = d_inode(realpath->dentry); |
d1d04ef8 | 43 | struct inode *inode = file_inode(file); |
4609e1f1 | 44 | struct mnt_idmap *real_idmap; |
d1d04ef8 MS |
45 | struct file *realfile; |
46 | const struct cred *old_cred; | |
81a33c1e | 47 | int flags = file->f_flags | OVL_OPEN_FLAGS; |
05acefb4 MS |
48 | int acc_mode = ACC_MODE(flags); |
49 | int err; | |
50 | ||
51 | if (flags & O_APPEND) | |
52 | acc_mode |= MAY_APPEND; | |
d1d04ef8 MS |
53 | |
54 | old_cred = ovl_override_creds(inode->i_sb); | |
4609e1f1 | 55 | real_idmap = mnt_idmap(realpath->mnt); |
4609e1f1 | 56 | err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode); |
05acefb4 MS |
57 | if (err) { |
58 | realfile = ERR_PTR(err); | |
05acefb4 | 59 | } else { |
01beba79 | 60 | if (!inode_owner_or_capable(real_idmap, realinode)) |
b6650dab MS |
61 | flags &= ~O_NOATIME; |
62 | ||
62d53c4a AG |
63 | realfile = backing_file_open(&file->f_path, flags, realpath, |
64 | current_cred()); | |
05acefb4 | 65 | } |
d1d04ef8 MS |
66 | revert_creds(old_cred); |
67 | ||
68 | pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n", | |
8c444d2a | 69 | file, file, ovl_whatisit(inode, realinode), file->f_flags, |
d1d04ef8 MS |
70 | realfile, IS_ERR(realfile) ? 0 : realfile->f_flags); |
71 | ||
72 | return realfile; | |
73 | } | |
74 | ||
2ef66b8a MS |
75 | #define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT) |
76 | ||
77 | static int ovl_change_flags(struct file *file, unsigned int flags) | |
78 | { | |
79 | struct inode *inode = file_inode(file); | |
80 | int err; | |
81 | ||
2ef66b8a MS |
82 | flags &= OVL_SETFL_MASK; |
83 | ||
84 | if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) | |
85 | return -EPERM; | |
86 | ||
a2ad63da N |
87 | if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT)) |
88 | return -EINVAL; | |
2ef66b8a MS |
89 | |
90 | if (file->f_op->check_flags) { | |
91 | err = file->f_op->check_flags(flags); | |
92 | if (err) | |
93 | return err; | |
94 | } | |
95 | ||
96 | spin_lock(&file->f_lock); | |
97 | file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags; | |
456b59e7 | 98 | file->f_iocb_flags = iocb_flags(file); |
2ef66b8a MS |
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; | |
42dd69ae | 109 | int err; |
2ef66b8a MS |
110 | |
111 | real->flags = 0; | |
112 | real->file = file->private_data; | |
113 | ||
42dd69ae | 114 | if (allow_meta) { |
1248ea4b | 115 | ovl_path_real(dentry, &realpath); |
42dd69ae | 116 | } else { |
184996e9 AL |
117 | /* lazy lookup and verify of lowerdata */ |
118 | err = ovl_verify_lowerdata(dentry); | |
42dd69ae AG |
119 | if (err) |
120 | return err; | |
121 | ||
1248ea4b | 122 | ovl_path_realdata(dentry, &realpath); |
42dd69ae | 123 | } |
41665644 AG |
124 | if (!realpath.dentry) |
125 | return -EIO; | |
8c444d2a | 126 | |
2ef66b8a | 127 | /* Has it been copied up since we'd opened it? */ |
1248ea4b | 128 | if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) { |
2ef66b8a | 129 | real->flags = FDPUT_FPUT; |
1248ea4b | 130 | real->file = ovl_open_realfile(file, &realpath); |
2ef66b8a MS |
131 | |
132 | return PTR_ERR_OR_ZERO(real->file); | |
133 | } | |
134 | ||
135 | /* Did the flags change since open? */ | |
81a33c1e | 136 | if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS)) |
2ef66b8a MS |
137 | return ovl_change_flags(real->file, file->f_flags); |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
8c444d2a VG |
142 | static int ovl_real_fdget(const struct file *file, struct fd *real) |
143 | { | |
61536bed AG |
144 | if (d_is_dir(file_dentry(file))) { |
145 | real->flags = 0; | |
146 | real->file = ovl_dir_real_file(file, false); | |
147 | ||
148 | return PTR_ERR_OR_ZERO(real->file); | |
149 | } | |
150 | ||
8c444d2a VG |
151 | return ovl_real_fdget_meta(file, real, false); |
152 | } | |
153 | ||
d1d04ef8 MS |
154 | static int ovl_open(struct inode *inode, struct file *file) |
155 | { | |
1248ea4b | 156 | struct dentry *dentry = file_dentry(file); |
d1d04ef8 | 157 | struct file *realfile; |
1248ea4b | 158 | struct path realpath; |
d1d04ef8 MS |
159 | int err; |
160 | ||
184996e9 AL |
161 | /* lazy lookup and verify lowerdata */ |
162 | err = ovl_verify_lowerdata(dentry); | |
42dd69ae AG |
163 | if (err) |
164 | return err; | |
165 | ||
1248ea4b | 166 | err = ovl_maybe_copy_up(dentry, file->f_flags); |
d1d04ef8 MS |
167 | if (err) |
168 | return err; | |
169 | ||
170 | /* No longer need these flags, so don't pass them on to underlying fs */ | |
171 | file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); | |
172 | ||
1248ea4b | 173 | ovl_path_realdata(dentry, &realpath); |
41665644 AG |
174 | if (!realpath.dentry) |
175 | return -EIO; | |
176 | ||
1248ea4b | 177 | realfile = ovl_open_realfile(file, &realpath); |
d1d04ef8 MS |
178 | if (IS_ERR(realfile)) |
179 | return PTR_ERR(realfile); | |
180 | ||
181 | file->private_data = realfile; | |
182 | ||
183 | return 0; | |
184 | } | |
185 | ||
186 | static int ovl_release(struct inode *inode, struct file *file) | |
187 | { | |
188 | fput(file->private_data); | |
189 | ||
190 | return 0; | |
191 | } | |
192 | ||
193 | static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) | |
194 | { | |
9e46b840 AG |
195 | struct inode *inode = file_inode(file); |
196 | struct fd real; | |
197 | const struct cred *old_cred; | |
a4ac9d45 | 198 | loff_t ret; |
9e46b840 AG |
199 | |
200 | /* | |
201 | * The two special cases below do not need to involve real fs, | |
202 | * so we can optimizing concurrent callers. | |
203 | */ | |
204 | if (offset == 0) { | |
205 | if (whence == SEEK_CUR) | |
206 | return file->f_pos; | |
207 | ||
208 | if (whence == SEEK_SET) | |
209 | return vfs_setpos(file, 0, 0); | |
210 | } | |
211 | ||
212 | ret = ovl_real_fdget(file, &real); | |
213 | if (ret) | |
214 | return ret; | |
215 | ||
216 | /* | |
217 | * Overlay file f_pos is the master copy that is preserved | |
218 | * through copy up and modified on read/write, but only real | |
219 | * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose | |
220 | * limitations that are more strict than ->s_maxbytes for specific | |
221 | * files, so we use the real file to perform seeks. | |
222 | */ | |
b1f9d385 | 223 | ovl_inode_lock(inode); |
9e46b840 AG |
224 | real.file->f_pos = file->f_pos; |
225 | ||
226 | old_cred = ovl_override_creds(inode->i_sb); | |
227 | ret = vfs_llseek(real.file, offset, whence); | |
228 | revert_creds(old_cred); | |
229 | ||
230 | file->f_pos = real.file->f_pos; | |
b1f9d385 | 231 | ovl_inode_unlock(inode); |
9e46b840 AG |
232 | |
233 | fdput(real); | |
d1d04ef8 | 234 | |
9e46b840 | 235 | return ret; |
d1d04ef8 MS |
236 | } |
237 | ||
16914e6f MS |
238 | static void ovl_file_accessed(struct file *file) |
239 | { | |
240 | struct inode *inode, *upperinode; | |
9aa71115 | 241 | struct timespec64 ctime, uctime; |
16914e6f MS |
242 | |
243 | if (file->f_flags & O_NOATIME) | |
244 | return; | |
245 | ||
246 | inode = file_inode(file); | |
247 | upperinode = ovl_inode_upper(inode); | |
248 | ||
249 | if (!upperinode) | |
250 | return; | |
251 | ||
9aa71115 JL |
252 | ctime = inode_get_ctime(inode); |
253 | uctime = inode_get_ctime(upperinode); | |
16914e6f | 254 | if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) || |
9aa71115 | 255 | !timespec64_equal(&ctime, &uctime))) { |
16914e6f | 256 | inode->i_mtime = upperinode->i_mtime; |
9aa71115 | 257 | inode_set_ctime_to_ts(inode, uctime); |
16914e6f MS |
258 | } |
259 | ||
260 | touch_atime(&file->f_path); | |
261 | } | |
262 | ||
b778e1ee | 263 | static rwf_t ovl_iocb_to_rwf(int ifl) |
16914e6f | 264 | { |
16914e6f MS |
265 | rwf_t flags = 0; |
266 | ||
267 | if (ifl & IOCB_NOWAIT) | |
268 | flags |= RWF_NOWAIT; | |
269 | if (ifl & IOCB_HIPRI) | |
270 | flags |= RWF_HIPRI; | |
271 | if (ifl & IOCB_DSYNC) | |
272 | flags |= RWF_DSYNC; | |
273 | if (ifl & IOCB_SYNC) | |
274 | flags |= RWF_SYNC; | |
275 | ||
276 | return flags; | |
277 | } | |
278 | ||
9a254403 | 279 | static inline void ovl_aio_put(struct ovl_aio_req *aio_req) |
280 | { | |
281 | if (refcount_dec_and_test(&aio_req->ref)) { | |
724768a3 | 282 | fput(aio_req->iocb.ki_filp); |
9a254403 | 283 | kmem_cache_free(ovl_aio_request_cachep, aio_req); |
284 | } | |
285 | } | |
286 | ||
2406a307 JX |
287 | static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req) |
288 | { | |
289 | struct kiocb *iocb = &aio_req->iocb; | |
290 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
291 | ||
292 | if (iocb->ki_flags & IOCB_WRITE) { | |
293 | struct inode *inode = file_inode(orig_iocb->ki_filp); | |
294 | ||
8f737126 | 295 | kiocb_end_write(iocb); |
2878dffc | 296 | ovl_copyattr(inode); |
2406a307 JX |
297 | } |
298 | ||
299 | orig_iocb->ki_pos = iocb->ki_pos; | |
9a254403 | 300 | ovl_aio_put(aio_req); |
2406a307 JX |
301 | } |
302 | ||
6b19b766 | 303 | static void ovl_aio_rw_complete(struct kiocb *iocb, long res) |
2406a307 JX |
304 | { |
305 | struct ovl_aio_req *aio_req = container_of(iocb, | |
306 | struct ovl_aio_req, iocb); | |
307 | struct kiocb *orig_iocb = aio_req->orig_iocb; | |
308 | ||
309 | ovl_aio_cleanup_handler(aio_req); | |
6b19b766 | 310 | orig_iocb->ki_complete(orig_iocb, res); |
2406a307 JX |
311 | } |
312 | ||
16914e6f MS |
313 | static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
314 | { | |
315 | struct file *file = iocb->ki_filp; | |
316 | struct fd real; | |
317 | const struct cred *old_cred; | |
318 | ssize_t ret; | |
319 | ||
320 | if (!iov_iter_count(iter)) | |
321 | return 0; | |
322 | ||
323 | ret = ovl_real_fdget(file, &real); | |
324 | if (ret) | |
325 | return ret; | |
326 | ||
1dc1eed4 MS |
327 | ret = -EINVAL; |
328 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 329 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
330 | goto out_fdput; |
331 | ||
16914e6f | 332 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 JX |
333 | if (is_sync_kiocb(iocb)) { |
334 | ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, | |
b778e1ee | 335 | ovl_iocb_to_rwf(iocb->ki_flags)); |
2406a307 JX |
336 | } else { |
337 | struct ovl_aio_req *aio_req; | |
338 | ||
339 | ret = -ENOMEM; | |
340 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
341 | if (!aio_req) | |
342 | goto out; | |
343 | ||
2406a307 | 344 | aio_req->orig_iocb = iocb; |
724768a3 | 345 | kiocb_clone(&aio_req->iocb, iocb, get_file(real.file)); |
2406a307 | 346 | aio_req->iocb.ki_complete = ovl_aio_rw_complete; |
9a254403 | 347 | refcount_set(&aio_req->ref, 2); |
2406a307 | 348 | ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter); |
9a254403 | 349 | ovl_aio_put(aio_req); |
2406a307 JX |
350 | if (ret != -EIOCBQUEUED) |
351 | ovl_aio_cleanup_handler(aio_req); | |
352 | } | |
353 | out: | |
16914e6f | 354 | revert_creds(old_cred); |
16914e6f | 355 | ovl_file_accessed(file); |
1dc1eed4 | 356 | out_fdput: |
16914e6f MS |
357 | fdput(real); |
358 | ||
359 | return ret; | |
360 | } | |
361 | ||
2a92e07e MS |
362 | static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) |
363 | { | |
364 | struct file *file = iocb->ki_filp; | |
365 | struct inode *inode = file_inode(file); | |
366 | struct fd real; | |
367 | const struct cred *old_cred; | |
368 | ssize_t ret; | |
c86243b0 | 369 | int ifl = iocb->ki_flags; |
2a92e07e MS |
370 | |
371 | if (!iov_iter_count(iter)) | |
372 | return 0; | |
373 | ||
374 | inode_lock(inode); | |
375 | /* Update mode */ | |
2878dffc | 376 | ovl_copyattr(inode); |
2a92e07e MS |
377 | ret = file_remove_privs(file); |
378 | if (ret) | |
379 | goto out_unlock; | |
380 | ||
381 | ret = ovl_real_fdget(file, &real); | |
382 | if (ret) | |
383 | goto out_unlock; | |
384 | ||
1dc1eed4 MS |
385 | ret = -EINVAL; |
386 | if (iocb->ki_flags & IOCB_DIRECT && | |
a2ad63da | 387 | !(real.file->f_mode & FMODE_CAN_ODIRECT)) |
1dc1eed4 MS |
388 | goto out_fdput; |
389 | ||
c86243b0 VG |
390 | if (!ovl_should_sync(OVL_FS(inode->i_sb))) |
391 | ifl &= ~(IOCB_DSYNC | IOCB_SYNC); | |
392 | ||
2d1b3bbc JA |
393 | /* |
394 | * Overlayfs doesn't support deferred completions, don't copy | |
395 | * this property in case it is set by the issuer. | |
396 | */ | |
397 | ifl &= ~IOCB_DIO_CALLER_COMP; | |
398 | ||
2a92e07e | 399 | old_cred = ovl_override_creds(file_inode(file)->i_sb); |
2406a307 JX |
400 | if (is_sync_kiocb(iocb)) { |
401 | file_start_write(real.file); | |
402 | ret = vfs_iter_write(real.file, iter, &iocb->ki_pos, | |
c86243b0 | 403 | ovl_iocb_to_rwf(ifl)); |
2406a307 JX |
404 | file_end_write(real.file); |
405 | /* Update size */ | |
2878dffc | 406 | ovl_copyattr(inode); |
2406a307 JX |
407 | } else { |
408 | struct ovl_aio_req *aio_req; | |
409 | ||
410 | ret = -ENOMEM; | |
411 | aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL); | |
412 | if (!aio_req) | |
413 | goto out; | |
414 | ||
2406a307 | 415 | aio_req->orig_iocb = iocb; |
724768a3 | 416 | kiocb_clone(&aio_req->iocb, iocb, get_file(real.file)); |
c86243b0 | 417 | aio_req->iocb.ki_flags = ifl; |
2406a307 | 418 | aio_req->iocb.ki_complete = ovl_aio_rw_complete; |
9a254403 | 419 | refcount_set(&aio_req->ref, 2); |
8f737126 | 420 | kiocb_start_write(&aio_req->iocb); |
2406a307 | 421 | ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter); |
9a254403 | 422 | ovl_aio_put(aio_req); |
2406a307 JX |
423 | if (ret != -EIOCBQUEUED) |
424 | ovl_aio_cleanup_handler(aio_req); | |
425 | } | |
426 | out: | |
2a92e07e | 427 | revert_creds(old_cred); |
1dc1eed4 | 428 | out_fdput: |
2a92e07e MS |
429 | fdput(real); |
430 | ||
431 | out_unlock: | |
432 | inode_unlock(inode); | |
433 | ||
434 | return ret; | |
435 | } | |
436 | ||
d4120d87 DH |
437 | static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, |
438 | struct pipe_inode_info *pipe, size_t len, | |
439 | unsigned int flags) | |
440 | { | |
441 | const struct cred *old_cred; | |
442 | struct fd real; | |
443 | ssize_t ret; | |
444 | ||
445 | ret = ovl_real_fdget(in, &real); | |
446 | if (ret) | |
447 | return ret; | |
448 | ||
449 | old_cred = ovl_override_creds(file_inode(in)->i_sb); | |
450 | ret = vfs_splice_read(real.file, ppos, pipe, len, flags); | |
451 | revert_creds(old_cred); | |
452 | ovl_file_accessed(in); | |
453 | ||
454 | fdput(real); | |
455 | return ret; | |
456 | } | |
457 | ||
9b91b6b0 MS |
458 | /* |
459 | * Calling iter_file_splice_write() directly from overlay's f_op may deadlock | |
460 | * due to lock order inversion between pipe->mutex in iter_file_splice_write() | |
461 | * and file_start_write(real.file) in ovl_write_iter(). | |
462 | * | |
463 | * So do everything ovl_write_iter() does and call iter_file_splice_write() on | |
464 | * the real file. | |
465 | */ | |
466 | static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out, | |
467 | loff_t *ppos, size_t len, unsigned int flags) | |
468 | { | |
469 | struct fd real; | |
470 | const struct cred *old_cred; | |
471 | struct inode *inode = file_inode(out); | |
9b91b6b0 MS |
472 | ssize_t ret; |
473 | ||
474 | inode_lock(inode); | |
475 | /* Update mode */ | |
2878dffc | 476 | ovl_copyattr(inode); |
9b91b6b0 MS |
477 | ret = file_remove_privs(out); |
478 | if (ret) | |
479 | goto out_unlock; | |
480 | ||
481 | ret = ovl_real_fdget(out, &real); | |
482 | if (ret) | |
483 | goto out_unlock; | |
484 | ||
485 | old_cred = ovl_override_creds(inode->i_sb); | |
486 | file_start_write(real.file); | |
487 | ||
488 | ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); | |
489 | ||
490 | file_end_write(real.file); | |
491 | /* Update size */ | |
2878dffc | 492 | ovl_copyattr(inode); |
9b91b6b0 MS |
493 | revert_creds(old_cred); |
494 | fdput(real); | |
495 | ||
496 | out_unlock: | |
497 | inode_unlock(inode); | |
498 | ||
499 | return ret; | |
500 | } | |
501 | ||
de30dfd6 MS |
502 | static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
503 | { | |
504 | struct fd real; | |
505 | const struct cred *old_cred; | |
506 | int ret; | |
507 | ||
335d3fc5 SD |
508 | ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb)); |
509 | if (ret <= 0) | |
510 | return ret; | |
c86243b0 | 511 | |
8c444d2a | 512 | ret = ovl_real_fdget_meta(file, &real, !datasync); |
de30dfd6 MS |
513 | if (ret) |
514 | return ret; | |
515 | ||
516 | /* Don't sync lower file for fear of receiving EROFS error */ | |
517 | if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) { | |
518 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
519 | ret = vfs_fsync_range(real.file, start, end, datasync); | |
520 | revert_creds(old_cred); | |
521 | } | |
522 | ||
523 | fdput(real); | |
524 | ||
525 | return ret; | |
526 | } | |
527 | ||
2f502839 MS |
528 | static int ovl_mmap(struct file *file, struct vm_area_struct *vma) |
529 | { | |
530 | struct file *realfile = file->private_data; | |
531 | const struct cred *old_cred; | |
532 | int ret; | |
533 | ||
534 | if (!realfile->f_op->mmap) | |
535 | return -ENODEV; | |
536 | ||
537 | if (WARN_ON(file != vma->vm_file)) | |
538 | return -EIO; | |
539 | ||
2896900e | 540 | vma_set_file(vma, realfile); |
2f502839 MS |
541 | |
542 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
543 | ret = call_mmap(vma->vm_file, vma); | |
544 | revert_creds(old_cred); | |
2f502839 MS |
545 | ovl_file_accessed(file); |
546 | ||
547 | return ret; | |
548 | } | |
549 | ||
aab8848c MS |
550 | static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
551 | { | |
552 | struct inode *inode = file_inode(file); | |
553 | struct fd real; | |
554 | const struct cred *old_cred; | |
555 | int ret; | |
556 | ||
23a8ce16 AG |
557 | inode_lock(inode); |
558 | /* Update mode */ | |
559 | ovl_copyattr(inode); | |
560 | ret = file_remove_privs(file); | |
561 | if (ret) | |
562 | goto out_unlock; | |
563 | ||
aab8848c MS |
564 | ret = ovl_real_fdget(file, &real); |
565 | if (ret) | |
23a8ce16 | 566 | goto out_unlock; |
aab8848c MS |
567 | |
568 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
569 | ret = vfs_fallocate(real.file, mode, offset, len); | |
570 | revert_creds(old_cred); | |
571 | ||
572 | /* Update size */ | |
2878dffc | 573 | ovl_copyattr(inode); |
aab8848c MS |
574 | |
575 | fdput(real); | |
576 | ||
23a8ce16 AG |
577 | out_unlock: |
578 | inode_unlock(inode); | |
579 | ||
aab8848c MS |
580 | return ret; |
581 | } | |
582 | ||
b833a366 AG |
583 | static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice) |
584 | { | |
585 | struct fd real; | |
586 | const struct cred *old_cred; | |
587 | int ret; | |
588 | ||
589 | ret = ovl_real_fdget(file, &real); | |
590 | if (ret) | |
591 | return ret; | |
592 | ||
593 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
594 | ret = vfs_fadvise(real.file, offset, len, advice); | |
595 | revert_creds(old_cred); | |
596 | ||
597 | fdput(real); | |
598 | ||
599 | return ret; | |
600 | } | |
601 | ||
8ede2055 MS |
602 | enum ovl_copyop { |
603 | OVL_COPY, | |
604 | OVL_CLONE, | |
605 | OVL_DEDUPE, | |
606 | }; | |
607 | ||
42ec3d4c | 608 | static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in, |
8ede2055 | 609 | struct file *file_out, loff_t pos_out, |
42ec3d4c | 610 | loff_t len, unsigned int flags, enum ovl_copyop op) |
8ede2055 MS |
611 | { |
612 | struct inode *inode_out = file_inode(file_out); | |
613 | struct fd real_in, real_out; | |
614 | const struct cred *old_cred; | |
42ec3d4c | 615 | loff_t ret; |
8ede2055 | 616 | |
b306e90f AG |
617 | inode_lock(inode_out); |
618 | if (op != OVL_DEDUPE) { | |
619 | /* Update mode */ | |
620 | ovl_copyattr(inode_out); | |
621 | ret = file_remove_privs(file_out); | |
622 | if (ret) | |
623 | goto out_unlock; | |
624 | } | |
625 | ||
8ede2055 MS |
626 | ret = ovl_real_fdget(file_out, &real_out); |
627 | if (ret) | |
b306e90f | 628 | goto out_unlock; |
8ede2055 MS |
629 | |
630 | ret = ovl_real_fdget(file_in, &real_in); | |
631 | if (ret) { | |
632 | fdput(real_out); | |
b306e90f | 633 | goto out_unlock; |
8ede2055 MS |
634 | } |
635 | ||
636 | old_cred = ovl_override_creds(file_inode(file_out)->i_sb); | |
637 | switch (op) { | |
638 | case OVL_COPY: | |
639 | ret = vfs_copy_file_range(real_in.file, pos_in, | |
640 | real_out.file, pos_out, len, flags); | |
641 | break; | |
642 | ||
643 | case OVL_CLONE: | |
a725356b | 644 | ret = vfs_clone_file_range(real_in.file, pos_in, |
452ce659 | 645 | real_out.file, pos_out, len, flags); |
8ede2055 MS |
646 | break; |
647 | ||
648 | case OVL_DEDUPE: | |
649 | ret = vfs_dedupe_file_range_one(real_in.file, pos_in, | |
df365836 DW |
650 | real_out.file, pos_out, len, |
651 | flags); | |
8ede2055 MS |
652 | break; |
653 | } | |
654 | revert_creds(old_cred); | |
655 | ||
656 | /* Update size */ | |
2878dffc | 657 | ovl_copyattr(inode_out); |
8ede2055 MS |
658 | |
659 | fdput(real_in); | |
660 | fdput(real_out); | |
661 | ||
b306e90f AG |
662 | out_unlock: |
663 | inode_unlock(inode_out); | |
664 | ||
8ede2055 MS |
665 | return ret; |
666 | } | |
667 | ||
668 | static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in, | |
669 | struct file *file_out, loff_t pos_out, | |
670 | size_t len, unsigned int flags) | |
671 | { | |
672 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags, | |
673 | OVL_COPY); | |
674 | } | |
675 | ||
42ec3d4c DW |
676 | static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in, |
677 | struct file *file_out, loff_t pos_out, | |
678 | loff_t len, unsigned int remap_flags) | |
8ede2055 | 679 | { |
2e5dfc99 DW |
680 | enum ovl_copyop op; |
681 | ||
682 | if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) | |
683 | return -EINVAL; | |
684 | ||
685 | if (remap_flags & REMAP_FILE_DEDUP) | |
686 | op = OVL_DEDUPE; | |
687 | else | |
688 | op = OVL_CLONE; | |
8ede2055 | 689 | |
8ede2055 MS |
690 | /* |
691 | * Don't copy up because of a dedupe request, this wouldn't make sense | |
692 | * most of the time (data would be duplicated instead of deduplicated). | |
693 | */ | |
2e5dfc99 DW |
694 | if (op == OVL_DEDUPE && |
695 | (!ovl_inode_upper(file_inode(file_in)) || | |
696 | !ovl_inode_upper(file_inode(file_out)))) | |
8ede2055 MS |
697 | return -EPERM; |
698 | ||
452ce659 DW |
699 | return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, |
700 | remap_flags, op); | |
8ede2055 MS |
701 | } |
702 | ||
1f0cb8bc SD |
703 | static int ovl_flush(struct file *file, fl_owner_t id) |
704 | { | |
705 | struct fd real; | |
706 | const struct cred *old_cred; | |
707 | int err; | |
708 | ||
709 | err = ovl_real_fdget(file, &real); | |
710 | if (err) | |
711 | return err; | |
712 | ||
713 | if (real.file->f_op->flush) { | |
714 | old_cred = ovl_override_creds(file_inode(file)->i_sb); | |
715 | err = real.file->f_op->flush(real.file, id); | |
716 | revert_creds(old_cred); | |
717 | } | |
718 | fdput(real); | |
719 | ||
720 | return err; | |
721 | } | |
722 | ||
d1d04ef8 MS |
723 | const struct file_operations ovl_file_operations = { |
724 | .open = ovl_open, | |
725 | .release = ovl_release, | |
726 | .llseek = ovl_llseek, | |
16914e6f | 727 | .read_iter = ovl_read_iter, |
2a92e07e | 728 | .write_iter = ovl_write_iter, |
de30dfd6 | 729 | .fsync = ovl_fsync, |
2f502839 | 730 | .mmap = ovl_mmap, |
aab8848c | 731 | .fallocate = ovl_fallocate, |
b833a366 | 732 | .fadvise = ovl_fadvise, |
1f0cb8bc | 733 | .flush = ovl_flush, |
d4120d87 | 734 | .splice_read = ovl_splice_read, |
9b91b6b0 | 735 | .splice_write = ovl_splice_write, |
8ede2055 MS |
736 | |
737 | .copy_file_range = ovl_copy_file_range, | |
2e5dfc99 | 738 | .remap_file_range = ovl_remap_file_range, |
d1d04ef8 | 739 | }; |
2406a307 JX |
740 | |
741 | int __init ovl_aio_request_cache_init(void) | |
742 | { | |
743 | ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req", | |
744 | sizeof(struct ovl_aio_req), | |
745 | 0, SLAB_HWCACHE_ALIGN, NULL); | |
746 | if (!ovl_aio_request_cachep) | |
747 | return -ENOMEM; | |
748 | ||
749 | return 0; | |
750 | } | |
751 | ||
752 | void ovl_aio_request_cache_destroy(void) | |
753 | { | |
754 | kmem_cache_destroy(ovl_aio_request_cachep); | |
755 | } |