Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/open.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/string.h> | |
8 | #include <linux/mm.h> | |
1da177e4 | 9 | #include <linux/file.h> |
9f3acc31 | 10 | #include <linux/fdtable.h> |
1da177e4 | 11 | #include <linux/quotaops.h> |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/slab.h> | |
15 | #include <linux/tty.h> | |
16 | #include <linux/namei.h> | |
17 | #include <linux/backing-dev.h> | |
16f7e0fe | 18 | #include <linux/capability.h> |
086f7316 | 19 | #include <linux/securebits.h> |
1da177e4 LT |
20 | #include <linux/security.h> |
21 | #include <linux/mount.h> | |
22 | #include <linux/vfs.h> | |
5590ff0d | 23 | #include <linux/fcntl.h> |
1da177e4 LT |
24 | #include <asm/uaccess.h> |
25 | #include <linux/fs.h> | |
ef3daeda | 26 | #include <linux/personality.h> |
1da177e4 LT |
27 | #include <linux/pagemap.h> |
28 | #include <linux/syscalls.h> | |
ab2af1f5 | 29 | #include <linux/rcupdate.h> |
73241ccc | 30 | #include <linux/audit.h> |
97ac7350 | 31 | #include <linux/falloc.h> |
1da177e4 | 32 | |
726c3342 | 33 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 LT |
34 | { |
35 | int retval = -ENODEV; | |
36 | ||
726c3342 | 37 | if (dentry) { |
1da177e4 | 38 | retval = -ENOSYS; |
726c3342 | 39 | if (dentry->d_sb->s_op->statfs) { |
1da177e4 | 40 | memset(buf, 0, sizeof(*buf)); |
726c3342 | 41 | retval = security_sb_statfs(dentry); |
1da177e4 LT |
42 | if (retval) |
43 | return retval; | |
726c3342 | 44 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
1da177e4 LT |
45 | if (retval == 0 && buf->f_frsize == 0) |
46 | buf->f_frsize = buf->f_bsize; | |
47 | } | |
48 | } | |
49 | return retval; | |
50 | } | |
51 | ||
52 | EXPORT_SYMBOL(vfs_statfs); | |
53 | ||
726c3342 | 54 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
1da177e4 LT |
55 | { |
56 | struct kstatfs st; | |
57 | int retval; | |
58 | ||
726c3342 | 59 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
60 | if (retval) |
61 | return retval; | |
62 | ||
63 | if (sizeof(*buf) == sizeof(st)) | |
64 | memcpy(buf, &st, sizeof(st)); | |
65 | else { | |
66 | if (sizeof buf->f_blocks == 4) { | |
f4a67cce JT |
67 | if ((st.f_blocks | st.f_bfree | st.f_bavail | |
68 | st.f_bsize | st.f_frsize) & | |
1da177e4 LT |
69 | 0xffffffff00000000ULL) |
70 | return -EOVERFLOW; | |
71 | /* | |
72 | * f_files and f_ffree may be -1; it's okay to stuff | |
73 | * that into 32 bits | |
74 | */ | |
75 | if (st.f_files != -1 && | |
76 | (st.f_files & 0xffffffff00000000ULL)) | |
77 | return -EOVERFLOW; | |
78 | if (st.f_ffree != -1 && | |
79 | (st.f_ffree & 0xffffffff00000000ULL)) | |
80 | return -EOVERFLOW; | |
81 | } | |
82 | ||
83 | buf->f_type = st.f_type; | |
84 | buf->f_bsize = st.f_bsize; | |
85 | buf->f_blocks = st.f_blocks; | |
86 | buf->f_bfree = st.f_bfree; | |
87 | buf->f_bavail = st.f_bavail; | |
88 | buf->f_files = st.f_files; | |
89 | buf->f_ffree = st.f_ffree; | |
90 | buf->f_fsid = st.f_fsid; | |
91 | buf->f_namelen = st.f_namelen; | |
92 | buf->f_frsize = st.f_frsize; | |
93 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
94 | } | |
95 | return 0; | |
96 | } | |
97 | ||
726c3342 | 98 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
1da177e4 LT |
99 | { |
100 | struct kstatfs st; | |
101 | int retval; | |
102 | ||
726c3342 | 103 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
104 | if (retval) |
105 | return retval; | |
106 | ||
107 | if (sizeof(*buf) == sizeof(st)) | |
108 | memcpy(buf, &st, sizeof(st)); | |
109 | else { | |
110 | buf->f_type = st.f_type; | |
111 | buf->f_bsize = st.f_bsize; | |
112 | buf->f_blocks = st.f_blocks; | |
113 | buf->f_bfree = st.f_bfree; | |
114 | buf->f_bavail = st.f_bavail; | |
115 | buf->f_files = st.f_files; | |
116 | buf->f_ffree = st.f_ffree; | |
117 | buf->f_fsid = st.f_fsid; | |
118 | buf->f_namelen = st.f_namelen; | |
119 | buf->f_frsize = st.f_frsize; | |
120 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
121 | } | |
122 | return 0; | |
123 | } | |
124 | ||
2d8f3038 | 125 | asmlinkage long sys_statfs(const char __user *pathname, struct statfs __user * buf) |
1da177e4 | 126 | { |
2d8f3038 | 127 | struct path path; |
1da177e4 LT |
128 | int error; |
129 | ||
2d8f3038 | 130 | error = user_path(pathname, &path); |
1da177e4 LT |
131 | if (!error) { |
132 | struct statfs tmp; | |
2d8f3038 | 133 | error = vfs_statfs_native(path.dentry, &tmp); |
1da177e4 LT |
134 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
135 | error = -EFAULT; | |
2d8f3038 | 136 | path_put(&path); |
1da177e4 LT |
137 | } |
138 | return error; | |
139 | } | |
140 | ||
141 | ||
2d8f3038 | 142 | asmlinkage long sys_statfs64(const char __user *pathname, size_t sz, struct statfs64 __user *buf) |
1da177e4 | 143 | { |
2d8f3038 | 144 | struct path path; |
1da177e4 LT |
145 | long error; |
146 | ||
147 | if (sz != sizeof(*buf)) | |
148 | return -EINVAL; | |
2d8f3038 | 149 | error = user_path(pathname, &path); |
1da177e4 LT |
150 | if (!error) { |
151 | struct statfs64 tmp; | |
2d8f3038 | 152 | error = vfs_statfs64(path.dentry, &tmp); |
1da177e4 LT |
153 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
154 | error = -EFAULT; | |
2d8f3038 | 155 | path_put(&path); |
1da177e4 LT |
156 | } |
157 | return error; | |
158 | } | |
159 | ||
160 | ||
161 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) | |
162 | { | |
163 | struct file * file; | |
164 | struct statfs tmp; | |
165 | int error; | |
166 | ||
167 | error = -EBADF; | |
168 | file = fget(fd); | |
169 | if (!file) | |
170 | goto out; | |
0f7fc9e4 | 171 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
1da177e4 LT |
172 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
173 | error = -EFAULT; | |
174 | fput(file); | |
175 | out: | |
176 | return error; | |
177 | } | |
178 | ||
179 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) | |
180 | { | |
181 | struct file * file; | |
182 | struct statfs64 tmp; | |
183 | int error; | |
184 | ||
185 | if (sz != sizeof(*buf)) | |
186 | return -EINVAL; | |
187 | ||
188 | error = -EBADF; | |
189 | file = fget(fd); | |
190 | if (!file) | |
191 | goto out; | |
0f7fc9e4 | 192 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
1da177e4 LT |
193 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
194 | error = -EFAULT; | |
195 | fput(file); | |
196 | out: | |
197 | return error; | |
198 | } | |
199 | ||
4a30131e N |
200 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
201 | struct file *filp) | |
1da177e4 LT |
202 | { |
203 | int err; | |
204 | struct iattr newattrs; | |
205 | ||
206 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
207 | if (length < 0) | |
208 | return -EINVAL; | |
209 | ||
210 | newattrs.ia_size = length; | |
4a30131e | 211 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
212 | if (filp) { |
213 | newattrs.ia_file = filp; | |
214 | newattrs.ia_valid |= ATTR_FILE; | |
215 | } | |
1da177e4 | 216 | |
7b82dc0e LT |
217 | /* Remove suid/sgid on truncate too */ |
218 | newattrs.ia_valid |= should_remove_suid(dentry); | |
219 | ||
1b1dcc1b | 220 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 221 | err = notify_change(dentry, &newattrs); |
1b1dcc1b | 222 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
223 | return err; |
224 | } | |
225 | ||
2d8f3038 | 226 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
1da177e4 | 227 | { |
2d8f3038 AV |
228 | struct path path; |
229 | struct inode *inode; | |
1da177e4 LT |
230 | int error; |
231 | ||
232 | error = -EINVAL; | |
233 | if (length < 0) /* sorry, but loff_t says... */ | |
234 | goto out; | |
235 | ||
2d8f3038 | 236 | error = user_path(pathname, &path); |
1da177e4 LT |
237 | if (error) |
238 | goto out; | |
2d8f3038 | 239 | inode = path.dentry->d_inode; |
1da177e4 LT |
240 | |
241 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
242 | error = -EISDIR; | |
243 | if (S_ISDIR(inode->i_mode)) | |
244 | goto dput_and_out; | |
245 | ||
246 | error = -EINVAL; | |
247 | if (!S_ISREG(inode->i_mode)) | |
248 | goto dput_and_out; | |
249 | ||
2d8f3038 | 250 | error = mnt_want_write(path.mnt); |
1da177e4 LT |
251 | if (error) |
252 | goto dput_and_out; | |
253 | ||
256984a8 | 254 | error = inode_permission(inode, MAY_WRITE); |
9ac9b847 DH |
255 | if (error) |
256 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
257 | |
258 | error = -EPERM; | |
c82e42da | 259 | if (IS_APPEND(inode)) |
9ac9b847 | 260 | goto mnt_drop_write_and_out; |
1da177e4 | 261 | |
9700382c | 262 | error = get_write_access(inode); |
1da177e4 | 263 | if (error) |
9ac9b847 | 264 | goto mnt_drop_write_and_out; |
1da177e4 | 265 | |
9700382c | 266 | /* |
267 | * Make sure that there are no leases. get_write_access() protects | |
268 | * against the truncate racing with a lease-granting setlease(). | |
269 | */ | |
270 | error = break_lease(inode, FMODE_WRITE); | |
1da177e4 | 271 | if (error) |
9700382c | 272 | goto put_write_and_out; |
1da177e4 LT |
273 | |
274 | error = locks_verify_truncate(inode, NULL, length); | |
be6d3e56 KT |
275 | if (!error) |
276 | error = security_path_truncate(&path, length, 0); | |
1da177e4 LT |
277 | if (!error) { |
278 | DQUOT_INIT(inode); | |
2d8f3038 | 279 | error = do_truncate(path.dentry, length, 0, NULL); |
1da177e4 | 280 | } |
1da177e4 | 281 | |
9700382c | 282 | put_write_and_out: |
283 | put_write_access(inode); | |
9ac9b847 | 284 | mnt_drop_write_and_out: |
2d8f3038 | 285 | mnt_drop_write(path.mnt); |
1da177e4 | 286 | dput_and_out: |
2d8f3038 | 287 | path_put(&path); |
1da177e4 LT |
288 | out: |
289 | return error; | |
290 | } | |
291 | ||
292 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | |
293 | { | |
294 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | |
295 | return do_sys_truncate(path, (long)length); | |
296 | } | |
297 | ||
b01ec0ef | 298 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
299 | { |
300 | struct inode * inode; | |
301 | struct dentry *dentry; | |
302 | struct file * file; | |
303 | int error; | |
304 | ||
305 | error = -EINVAL; | |
306 | if (length < 0) | |
307 | goto out; | |
308 | error = -EBADF; | |
309 | file = fget(fd); | |
310 | if (!file) | |
311 | goto out; | |
312 | ||
313 | /* explicitly opened as large or we are on 64-bit box */ | |
314 | if (file->f_flags & O_LARGEFILE) | |
315 | small = 0; | |
316 | ||
0f7fc9e4 | 317 | dentry = file->f_path.dentry; |
1da177e4 LT |
318 | inode = dentry->d_inode; |
319 | error = -EINVAL; | |
320 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
321 | goto out_putf; | |
322 | ||
323 | error = -EINVAL; | |
324 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
325 | if (small && length > MAX_NON_LFS) | |
326 | goto out_putf; | |
327 | ||
328 | error = -EPERM; | |
329 | if (IS_APPEND(inode)) | |
330 | goto out_putf; | |
331 | ||
332 | error = locks_verify_truncate(inode, file, length); | |
be6d3e56 KT |
333 | if (!error) |
334 | error = security_path_truncate(&file->f_path, length, | |
335 | ATTR_MTIME|ATTR_CTIME); | |
1da177e4 | 336 | if (!error) |
6e656be8 | 337 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
1da177e4 LT |
338 | out_putf: |
339 | fput(file); | |
340 | out: | |
341 | return error; | |
342 | } | |
343 | ||
344 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | |
345 | { | |
0a489cb3 | 346 | long ret = do_sys_ftruncate(fd, length, 1); |
385910f2 | 347 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 348 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 349 | return ret; |
1da177e4 LT |
350 | } |
351 | ||
352 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
353 | #if BITS_PER_LONG == 32 | |
354 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
355 | { | |
356 | return do_sys_truncate(path, length); | |
357 | } | |
358 | ||
359 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
360 | { | |
0a489cb3 | 361 | long ret = do_sys_ftruncate(fd, length, 0); |
385910f2 | 362 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 363 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 364 | return ret; |
1da177e4 LT |
365 | } |
366 | #endif | |
367 | ||
97ac7350 AA |
368 | asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) |
369 | { | |
370 | struct file *file; | |
371 | struct inode *inode; | |
372 | long ret = -EINVAL; | |
373 | ||
374 | if (offset < 0 || len <= 0) | |
375 | goto out; | |
376 | ||
377 | /* Return error if mode is not supported */ | |
378 | ret = -EOPNOTSUPP; | |
379 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) | |
380 | goto out; | |
381 | ||
382 | ret = -EBADF; | |
383 | file = fget(fd); | |
384 | if (!file) | |
385 | goto out; | |
386 | if (!(file->f_mode & FMODE_WRITE)) | |
387 | goto out_fput; | |
388 | /* | |
389 | * Revalidate the write permissions, in case security policy has | |
390 | * changed since the files were opened. | |
391 | */ | |
392 | ret = security_file_permission(file, MAY_WRITE); | |
393 | if (ret) | |
394 | goto out_fput; | |
395 | ||
396 | inode = file->f_path.dentry->d_inode; | |
397 | ||
398 | ret = -ESPIPE; | |
399 | if (S_ISFIFO(inode->i_mode)) | |
400 | goto out_fput; | |
401 | ||
402 | ret = -ENODEV; | |
403 | /* | |
404 | * Let individual file system decide if it supports preallocation | |
405 | * for directories or not. | |
406 | */ | |
407 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) | |
408 | goto out_fput; | |
409 | ||
410 | ret = -EFBIG; | |
411 | /* Check for wrap through zero too */ | |
412 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
413 | goto out_fput; | |
414 | ||
415 | if (inode->i_op && inode->i_op->fallocate) | |
416 | ret = inode->i_op->fallocate(inode, mode, offset, len); | |
417 | else | |
0d786d4a | 418 | ret = -EOPNOTSUPP; |
97ac7350 AA |
419 | |
420 | out_fput: | |
421 | fput(file); | |
422 | out: | |
423 | return ret; | |
424 | } | |
425 | ||
1da177e4 LT |
426 | /* |
427 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
428 | * We do this by temporarily clearing all FS-related capabilities and | |
429 | * switching the fsuid/fsgid around to the real ones. | |
430 | */ | |
5590ff0d | 431 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
1da177e4 | 432 | { |
d84f4f99 DH |
433 | const struct cred *old_cred; |
434 | struct cred *override_cred; | |
2d8f3038 | 435 | struct path path; |
256984a8 | 436 | struct inode *inode; |
1da177e4 LT |
437 | int res; |
438 | ||
439 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
440 | return -EINVAL; | |
441 | ||
d84f4f99 DH |
442 | override_cred = prepare_creds(); |
443 | if (!override_cred) | |
444 | return -ENOMEM; | |
1da177e4 | 445 | |
d84f4f99 DH |
446 | override_cred->fsuid = override_cred->uid; |
447 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 448 | |
086f7316 | 449 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 450 | /* Clear the capabilities if we switch to a non-root user */ |
d84f4f99 DH |
451 | if (override_cred->uid) |
452 | cap_clear(override_cred->cap_effective); | |
086f7316 | 453 | else |
d84f4f99 DH |
454 | override_cred->cap_effective = |
455 | override_cred->cap_permitted; | |
086f7316 | 456 | } |
1da177e4 | 457 | |
d84f4f99 DH |
458 | old_cred = override_creds(override_cred); |
459 | ||
2d8f3038 | 460 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
6902d925 DH |
461 | if (res) |
462 | goto out; | |
463 | ||
2d8f3038 | 464 | inode = path.dentry->d_inode; |
256984a8 AV |
465 | |
466 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
467 | /* |
468 | * MAY_EXEC on regular files is denied if the fs is mounted | |
469 | * with the "noexec" flag. | |
470 | */ | |
471 | res = -EACCES; | |
2d8f3038 | 472 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
30524472 AV |
473 | goto out_path_release; |
474 | } | |
475 | ||
256984a8 | 476 | res = inode_permission(inode, mode | MAY_ACCESS); |
6902d925 | 477 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 478 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 479 | goto out_path_release; |
2f676cbc DH |
480 | /* |
481 | * This is a rare case where using __mnt_is_readonly() | |
482 | * is OK without a mnt_want/drop_write() pair. Since | |
483 | * no actual write to the fs is performed here, we do | |
484 | * not need to telegraph to that to anyone. | |
485 | * | |
486 | * By doing this, we accept that this access is | |
487 | * inherently racy and know that the fs may change | |
488 | * state before we even see this result. | |
489 | */ | |
2d8f3038 | 490 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 491 | res = -EROFS; |
1da177e4 | 492 | |
6902d925 | 493 | out_path_release: |
2d8f3038 | 494 | path_put(&path); |
6902d925 | 495 | out: |
d84f4f99 DH |
496 | revert_creds(old_cred); |
497 | put_cred(override_cred); | |
1da177e4 LT |
498 | return res; |
499 | } | |
500 | ||
5590ff0d UD |
501 | asmlinkage long sys_access(const char __user *filename, int mode) |
502 | { | |
503 | return sys_faccessat(AT_FDCWD, filename, mode); | |
504 | } | |
505 | ||
1da177e4 LT |
506 | asmlinkage long sys_chdir(const char __user * filename) |
507 | { | |
2d8f3038 | 508 | struct path path; |
1da177e4 LT |
509 | int error; |
510 | ||
2d8f3038 | 511 | error = user_path_dir(filename, &path); |
1da177e4 LT |
512 | if (error) |
513 | goto out; | |
514 | ||
2d8f3038 | 515 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
1da177e4 LT |
516 | if (error) |
517 | goto dput_and_out; | |
518 | ||
2d8f3038 | 519 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
520 | |
521 | dput_and_out: | |
2d8f3038 | 522 | path_put(&path); |
1da177e4 LT |
523 | out: |
524 | return error; | |
525 | } | |
526 | ||
527 | asmlinkage long sys_fchdir(unsigned int fd) | |
528 | { | |
529 | struct file *file; | |
1da177e4 | 530 | struct inode *inode; |
1da177e4 LT |
531 | int error; |
532 | ||
533 | error = -EBADF; | |
534 | file = fget(fd); | |
535 | if (!file) | |
536 | goto out; | |
537 | ||
ac748a09 | 538 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
539 | |
540 | error = -ENOTDIR; | |
541 | if (!S_ISDIR(inode->i_mode)) | |
542 | goto out_putf; | |
543 | ||
256984a8 | 544 | error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); |
1da177e4 | 545 | if (!error) |
ac748a09 | 546 | set_fs_pwd(current->fs, &file->f_path); |
1da177e4 LT |
547 | out_putf: |
548 | fput(file); | |
549 | out: | |
550 | return error; | |
551 | } | |
552 | ||
553 | asmlinkage long sys_chroot(const char __user * filename) | |
554 | { | |
2d8f3038 | 555 | struct path path; |
1da177e4 LT |
556 | int error; |
557 | ||
2d8f3038 | 558 | error = user_path_dir(filename, &path); |
1da177e4 LT |
559 | if (error) |
560 | goto out; | |
561 | ||
2d8f3038 | 562 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS); |
1da177e4 LT |
563 | if (error) |
564 | goto dput_and_out; | |
565 | ||
566 | error = -EPERM; | |
567 | if (!capable(CAP_SYS_CHROOT)) | |
568 | goto dput_and_out; | |
569 | ||
2d8f3038 | 570 | set_fs_root(current->fs, &path); |
1da177e4 LT |
571 | error = 0; |
572 | dput_and_out: | |
2d8f3038 | 573 | path_put(&path); |
1da177e4 LT |
574 | out: |
575 | return error; | |
576 | } | |
577 | ||
578 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
579 | { | |
580 | struct inode * inode; | |
581 | struct dentry * dentry; | |
582 | struct file * file; | |
583 | int err = -EBADF; | |
584 | struct iattr newattrs; | |
585 | ||
586 | file = fget(fd); | |
587 | if (!file) | |
588 | goto out; | |
589 | ||
0f7fc9e4 | 590 | dentry = file->f_path.dentry; |
1da177e4 LT |
591 | inode = dentry->d_inode; |
592 | ||
5a190ae6 | 593 | audit_inode(NULL, dentry); |
73241ccc | 594 | |
2af482a7 DH |
595 | err = mnt_want_write(file->f_path.mnt); |
596 | if (err) | |
1da177e4 | 597 | goto out_putf; |
1b1dcc1b | 598 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
599 | if (mode == (mode_t) -1) |
600 | mode = inode->i_mode; | |
601 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
602 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
603 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 604 | mutex_unlock(&inode->i_mutex); |
2af482a7 | 605 | mnt_drop_write(file->f_path.mnt); |
1da177e4 LT |
606 | out_putf: |
607 | fput(file); | |
608 | out: | |
609 | return err; | |
610 | } | |
611 | ||
5590ff0d UD |
612 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
613 | mode_t mode) | |
1da177e4 | 614 | { |
2d8f3038 AV |
615 | struct path path; |
616 | struct inode *inode; | |
1da177e4 LT |
617 | int error; |
618 | struct iattr newattrs; | |
619 | ||
2d8f3038 | 620 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
621 | if (error) |
622 | goto out; | |
2d8f3038 | 623 | inode = path.dentry->d_inode; |
1da177e4 | 624 | |
2d8f3038 | 625 | error = mnt_want_write(path.mnt); |
2af482a7 | 626 | if (error) |
1da177e4 | 627 | goto dput_and_out; |
1b1dcc1b | 628 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
629 | if (mode == (mode_t) -1) |
630 | mode = inode->i_mode; | |
631 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
632 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
2d8f3038 | 633 | error = notify_change(path.dentry, &newattrs); |
1b1dcc1b | 634 | mutex_unlock(&inode->i_mutex); |
2d8f3038 | 635 | mnt_drop_write(path.mnt); |
1da177e4 | 636 | dput_and_out: |
2d8f3038 | 637 | path_put(&path); |
1da177e4 LT |
638 | out: |
639 | return error; | |
640 | } | |
641 | ||
5590ff0d UD |
642 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
643 | { | |
644 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
645 | } | |
646 | ||
1da177e4 LT |
647 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
648 | { | |
beb29e05 | 649 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
650 | int error; |
651 | struct iattr newattrs; | |
652 | ||
1da177e4 LT |
653 | newattrs.ia_valid = ATTR_CTIME; |
654 | if (user != (uid_t) -1) { | |
655 | newattrs.ia_valid |= ATTR_UID; | |
656 | newattrs.ia_uid = user; | |
657 | } | |
658 | if (group != (gid_t) -1) { | |
659 | newattrs.ia_valid |= ATTR_GID; | |
660 | newattrs.ia_gid = group; | |
661 | } | |
662 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
663 | newattrs.ia_valid |= |
664 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
1b1dcc1b | 665 | mutex_lock(&inode->i_mutex); |
1da177e4 | 666 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 667 | mutex_unlock(&inode->i_mutex); |
beb29e05 | 668 | |
1da177e4 LT |
669 | return error; |
670 | } | |
671 | ||
672 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
673 | { | |
2d8f3038 | 674 | struct path path; |
1da177e4 LT |
675 | int error; |
676 | ||
2d8f3038 | 677 | error = user_path(filename, &path); |
6902d925 DH |
678 | if (error) |
679 | goto out; | |
2d8f3038 | 680 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
681 | if (error) |
682 | goto out_release; | |
2d8f3038 AV |
683 | error = chown_common(path.dentry, user, group); |
684 | mnt_drop_write(path.mnt); | |
2af482a7 | 685 | out_release: |
2d8f3038 | 686 | path_put(&path); |
6902d925 | 687 | out: |
1da177e4 LT |
688 | return error; |
689 | } | |
690 | ||
5590ff0d UD |
691 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
692 | gid_t group, int flag) | |
693 | { | |
2d8f3038 | 694 | struct path path; |
5590ff0d UD |
695 | int error = -EINVAL; |
696 | int follow; | |
697 | ||
698 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
699 | goto out; | |
700 | ||
701 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
2d8f3038 | 702 | error = user_path_at(dfd, filename, follow, &path); |
6902d925 DH |
703 | if (error) |
704 | goto out; | |
2d8f3038 | 705 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
706 | if (error) |
707 | goto out_release; | |
2d8f3038 AV |
708 | error = chown_common(path.dentry, user, group); |
709 | mnt_drop_write(path.mnt); | |
2af482a7 | 710 | out_release: |
2d8f3038 | 711 | path_put(&path); |
5590ff0d UD |
712 | out: |
713 | return error; | |
714 | } | |
715 | ||
1da177e4 LT |
716 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
717 | { | |
2d8f3038 | 718 | struct path path; |
1da177e4 LT |
719 | int error; |
720 | ||
2d8f3038 | 721 | error = user_lpath(filename, &path); |
6902d925 DH |
722 | if (error) |
723 | goto out; | |
2d8f3038 | 724 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
725 | if (error) |
726 | goto out_release; | |
2d8f3038 AV |
727 | error = chown_common(path.dentry, user, group); |
728 | mnt_drop_write(path.mnt); | |
2af482a7 | 729 | out_release: |
2d8f3038 | 730 | path_put(&path); |
6902d925 | 731 | out: |
1da177e4 LT |
732 | return error; |
733 | } | |
734 | ||
735 | ||
736 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
737 | { | |
738 | struct file * file; | |
739 | int error = -EBADF; | |
6902d925 | 740 | struct dentry * dentry; |
1da177e4 LT |
741 | |
742 | file = fget(fd); | |
6902d925 DH |
743 | if (!file) |
744 | goto out; | |
745 | ||
2af482a7 DH |
746 | error = mnt_want_write(file->f_path.mnt); |
747 | if (error) | |
748 | goto out_fput; | |
0f7fc9e4 | 749 | dentry = file->f_path.dentry; |
5a190ae6 | 750 | audit_inode(NULL, dentry); |
6902d925 | 751 | error = chown_common(dentry, user, group); |
2af482a7 DH |
752 | mnt_drop_write(file->f_path.mnt); |
753 | out_fput: | |
6902d925 DH |
754 | fput(file); |
755 | out: | |
1da177e4 LT |
756 | return error; |
757 | } | |
758 | ||
4a3fd211 DH |
759 | /* |
760 | * You have to be very careful that these write | |
761 | * counts get cleaned up in error cases and | |
762 | * upon __fput(). This should probably never | |
763 | * be called outside of __dentry_open(). | |
764 | */ | |
765 | static inline int __get_file_write_access(struct inode *inode, | |
766 | struct vfsmount *mnt) | |
767 | { | |
768 | int error; | |
769 | error = get_write_access(inode); | |
770 | if (error) | |
771 | return error; | |
772 | /* | |
773 | * Do not take mount writer counts on | |
774 | * special files since no writes to | |
775 | * the mount itself will occur. | |
776 | */ | |
777 | if (!special_file(inode->i_mode)) { | |
778 | /* | |
779 | * Balanced in __fput() | |
780 | */ | |
781 | error = mnt_want_write(mnt); | |
782 | if (error) | |
783 | put_write_access(inode); | |
784 | } | |
785 | return error; | |
786 | } | |
787 | ||
a1a5b3d9 | 788 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a | 789 | int flags, struct file *f, |
745ca247 DH |
790 | int (*open)(struct inode *, struct file *), |
791 | const struct cred *cred) | |
1da177e4 | 792 | { |
1da177e4 LT |
793 | struct inode *inode; |
794 | int error; | |
795 | ||
1da177e4 | 796 | f->f_flags = flags; |
aeb5d727 | 797 | f->f_mode = (__force fmode_t)((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
a1a5b3d9 | 798 | FMODE_PREAD | FMODE_PWRITE; |
1da177e4 LT |
799 | inode = dentry->d_inode; |
800 | if (f->f_mode & FMODE_WRITE) { | |
4a3fd211 | 801 | error = __get_file_write_access(inode, mnt); |
1da177e4 LT |
802 | if (error) |
803 | goto cleanup_file; | |
ad775f5a DH |
804 | if (!special_file(inode->i_mode)) |
805 | file_take_write(f); | |
1da177e4 LT |
806 | } |
807 | ||
808 | f->f_mapping = inode->i_mapping; | |
0f7fc9e4 JJS |
809 | f->f_path.dentry = dentry; |
810 | f->f_path.mnt = mnt; | |
1da177e4 LT |
811 | f->f_pos = 0; |
812 | f->f_op = fops_get(inode->i_fop); | |
813 | file_move(f, &inode->i_sb->s_files); | |
814 | ||
745ca247 | 815 | error = security_dentry_open(f, cred); |
788e7dd4 YN |
816 | if (error) |
817 | goto cleanup_all; | |
818 | ||
834f2a4a TM |
819 | if (!open && f->f_op) |
820 | open = f->f_op->open; | |
821 | if (open) { | |
822 | error = open(inode, f); | |
1da177e4 LT |
823 | if (error) |
824 | goto cleanup_all; | |
825 | } | |
834f2a4a | 826 | |
1da177e4 LT |
827 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
828 | ||
829 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
830 | ||
831 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
832 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
833 | if (!f->f_mapping->a_ops || |
834 | ((!f->f_mapping->a_ops->direct_IO) && | |
70688e4d | 835 | (!f->f_mapping->a_ops->get_xip_mem))) { |
1da177e4 LT |
836 | fput(f); |
837 | f = ERR_PTR(-EINVAL); | |
838 | } | |
839 | } | |
840 | ||
841 | return f; | |
842 | ||
843 | cleanup_all: | |
844 | fops_put(f->f_op); | |
4a3fd211 | 845 | if (f->f_mode & FMODE_WRITE) { |
1da177e4 | 846 | put_write_access(inode); |
ad775f5a DH |
847 | if (!special_file(inode->i_mode)) { |
848 | /* | |
849 | * We don't consider this a real | |
850 | * mnt_want/drop_write() pair | |
851 | * because it all happenend right | |
852 | * here, so just reset the state. | |
853 | */ | |
854 | file_reset_write(f); | |
4a3fd211 | 855 | mnt_drop_write(mnt); |
ad775f5a | 856 | } |
4a3fd211 | 857 | } |
1da177e4 | 858 | file_kill(f); |
0f7fc9e4 JJS |
859 | f->f_path.dentry = NULL; |
860 | f->f_path.mnt = NULL; | |
1da177e4 LT |
861 | cleanup_file: |
862 | put_filp(f); | |
1da177e4 LT |
863 | dput(dentry); |
864 | mntput(mnt); | |
865 | return ERR_PTR(error); | |
866 | } | |
867 | ||
834f2a4a TM |
868 | /** |
869 | * lookup_instantiate_filp - instantiates the open intent filp | |
870 | * @nd: pointer to nameidata | |
871 | * @dentry: pointer to dentry | |
872 | * @open: open callback | |
873 | * | |
874 | * Helper for filesystems that want to use lookup open intents and pass back | |
875 | * a fully instantiated struct file to the caller. | |
876 | * This function is meant to be called from within a filesystem's | |
877 | * lookup method. | |
9a56c213 OD |
878 | * Beware of calling it for non-regular files! Those ->open methods might block |
879 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
880 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
881 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
882 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
883 | * path information remains valid. | |
884 | * If the open callback is set to NULL, then the standard f_op->open() | |
885 | * filesystem callback is substituted. | |
886 | */ | |
887 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
888 | int (*open)(struct inode *, struct file *)) | |
889 | { | |
745ca247 DH |
890 | const struct cred *cred = current_cred(); |
891 | ||
834f2a4a TM |
892 | if (IS_ERR(nd->intent.open.file)) |
893 | goto out; | |
894 | if (IS_ERR(dentry)) | |
895 | goto out_err; | |
4ac91378 | 896 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
834f2a4a TM |
897 | nd->intent.open.flags - 1, |
898 | nd->intent.open.file, | |
745ca247 | 899 | open, cred); |
834f2a4a TM |
900 | out: |
901 | return nd->intent.open.file; | |
902 | out_err: | |
903 | release_open_intent(nd); | |
904 | nd->intent.open.file = (struct file *)dentry; | |
905 | goto out; | |
906 | } | |
907 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
908 | ||
909 | /** | |
910 | * nameidata_to_filp - convert a nameidata to an open filp. | |
911 | * @nd: pointer to nameidata | |
912 | * @flags: open flags | |
913 | * | |
914 | * Note that this function destroys the original nameidata | |
915 | */ | |
916 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
917 | { | |
745ca247 | 918 | const struct cred *cred = current_cred(); |
834f2a4a TM |
919 | struct file *filp; |
920 | ||
921 | /* Pick up the filp from the open intent */ | |
922 | filp = nd->intent.open.file; | |
923 | /* Has the filesystem initialised the file for us? */ | |
0f7fc9e4 | 924 | if (filp->f_path.dentry == NULL) |
4ac91378 | 925 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
745ca247 | 926 | NULL, cred); |
834f2a4a | 927 | else |
1d957f9b | 928 | path_put(&nd->path); |
834f2a4a TM |
929 | return filp; |
930 | } | |
931 | ||
6fdcc216 PS |
932 | /* |
933 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
934 | * error. | |
935 | */ | |
745ca247 DH |
936 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags, |
937 | const struct cred *cred) | |
a1a5b3d9 PS |
938 | { |
939 | int error; | |
940 | struct file *f; | |
941 | ||
322ee5b3 CH |
942 | /* |
943 | * We must always pass in a valid mount pointer. Historically | |
944 | * callers got away with not passing it, but we must enforce this at | |
945 | * the earliest possible point now to avoid strange problems deep in the | |
946 | * filesystem stack. | |
947 | */ | |
948 | if (!mnt) { | |
949 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); | |
950 | dump_stack(); | |
951 | return ERR_PTR(-EINVAL); | |
952 | } | |
953 | ||
a1a5b3d9 PS |
954 | error = -ENFILE; |
955 | f = get_empty_filp(); | |
6fdcc216 PS |
956 | if (f == NULL) { |
957 | dput(dentry); | |
958 | mntput(mnt); | |
a1a5b3d9 | 959 | return ERR_PTR(error); |
6fdcc216 | 960 | } |
a1a5b3d9 | 961 | |
745ca247 | 962 | return __dentry_open(dentry, mnt, flags, f, NULL, cred); |
a1a5b3d9 | 963 | } |
1da177e4 LT |
964 | EXPORT_SYMBOL(dentry_open); |
965 | ||
b01ec0ef | 966 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 967 | { |
badf1662 DS |
968 | struct fdtable *fdt = files_fdtable(files); |
969 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
970 | if (fd < files->next_fd) |
971 | files->next_fd = fd; | |
1da177e4 LT |
972 | } |
973 | ||
fc9b52cd | 974 | void put_unused_fd(unsigned int fd) |
1da177e4 LT |
975 | { |
976 | struct files_struct *files = current->files; | |
977 | spin_lock(&files->file_lock); | |
978 | __put_unused_fd(files, fd); | |
979 | spin_unlock(&files->file_lock); | |
980 | } | |
981 | ||
982 | EXPORT_SYMBOL(put_unused_fd); | |
983 | ||
984 | /* | |
5590ff0d | 985 | * Install a file pointer in the fd array. |
1da177e4 LT |
986 | * |
987 | * The VFS is full of places where we drop the files lock between | |
988 | * setting the open_fds bitmap and installing the file in the file | |
989 | * array. At any such point, we are vulnerable to a dup2() race | |
990 | * installing a file in the array before us. We need to detect this and | |
991 | * fput() the struct file we are about to overwrite in this case. | |
992 | * | |
993 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
994 | * will follow. | |
995 | */ | |
996 | ||
fc9b52cd | 997 | void fd_install(unsigned int fd, struct file *file) |
1da177e4 LT |
998 | { |
999 | struct files_struct *files = current->files; | |
badf1662 | 1000 | struct fdtable *fdt; |
1da177e4 | 1001 | spin_lock(&files->file_lock); |
badf1662 | 1002 | fdt = files_fdtable(files); |
ab2af1f5 DS |
1003 | BUG_ON(fdt->fd[fd] != NULL); |
1004 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
1005 | spin_unlock(&files->file_lock); |
1006 | } | |
1007 | ||
1008 | EXPORT_SYMBOL(fd_install); | |
1009 | ||
5590ff0d | 1010 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 1011 | { |
e922efc3 MS |
1012 | char *tmp = getname(filename); |
1013 | int fd = PTR_ERR(tmp); | |
1da177e4 | 1014 | |
1da177e4 | 1015 | if (!IS_ERR(tmp)) { |
f23513e8 | 1016 | fd = get_unused_fd_flags(flags); |
1da177e4 | 1017 | if (fd >= 0) { |
5590ff0d | 1018 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
1019 | if (IS_ERR(f)) { |
1020 | put_unused_fd(fd); | |
1021 | fd = PTR_ERR(f); | |
1022 | } else { | |
0f7fc9e4 | 1023 | fsnotify_open(f->f_path.dentry); |
fed2fc18 TN |
1024 | fd_install(fd, f); |
1025 | } | |
1da177e4 | 1026 | } |
1da177e4 LT |
1027 | putname(tmp); |
1028 | } | |
1029 | return fd; | |
1da177e4 | 1030 | } |
e922efc3 MS |
1031 | |
1032 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
1033 | { | |
385910f2 LT |
1034 | long ret; |
1035 | ||
e922efc3 MS |
1036 | if (force_o_largefile()) |
1037 | flags |= O_LARGEFILE; | |
1038 | ||
385910f2 LT |
1039 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
1040 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1041 | asmlinkage_protect(3, ret, filename, flags, mode); |
385910f2 | 1042 | return ret; |
e922efc3 | 1043 | } |
1da177e4 | 1044 | |
5590ff0d UD |
1045 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
1046 | int mode) | |
1047 | { | |
385910f2 LT |
1048 | long ret; |
1049 | ||
5590ff0d UD |
1050 | if (force_o_largefile()) |
1051 | flags |= O_LARGEFILE; | |
1052 | ||
385910f2 LT |
1053 | ret = do_sys_open(dfd, filename, flags, mode); |
1054 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1055 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
385910f2 | 1056 | return ret; |
5590ff0d | 1057 | } |
5590ff0d | 1058 | |
1da177e4 LT |
1059 | #ifndef __alpha__ |
1060 | ||
1061 | /* | |
1062 | * For backward compatibility? Maybe this should be moved | |
1063 | * into arch/i386 instead? | |
1064 | */ | |
1065 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1066 | { | |
1067 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1068 | } | |
1069 | ||
1070 | #endif | |
1071 | ||
1072 | /* | |
1073 | * "id" is the POSIX thread ID. We use the | |
1074 | * files pointer for this.. | |
1075 | */ | |
1076 | int filp_close(struct file *filp, fl_owner_t id) | |
1077 | { | |
45778ca8 | 1078 | int retval = 0; |
1da177e4 LT |
1079 | |
1080 | if (!file_count(filp)) { | |
1081 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1082 | return 0; |
1da177e4 LT |
1083 | } |
1084 | ||
45778ca8 | 1085 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1086 | retval = filp->f_op->flush(filp, id); |
1da177e4 LT |
1087 | |
1088 | dnotify_flush(filp, id); | |
1089 | locks_remove_posix(filp, id); | |
1090 | fput(filp); | |
1091 | return retval; | |
1092 | } | |
1093 | ||
1094 | EXPORT_SYMBOL(filp_close); | |
1095 | ||
1096 | /* | |
1097 | * Careful here! We test whether the file pointer is NULL before | |
1098 | * releasing the fd. This ensures that one clone task can't release | |
1099 | * an fd while another clone is opening it. | |
1100 | */ | |
1101 | asmlinkage long sys_close(unsigned int fd) | |
1102 | { | |
1103 | struct file * filp; | |
1104 | struct files_struct *files = current->files; | |
badf1662 | 1105 | struct fdtable *fdt; |
ee731f4f | 1106 | int retval; |
1da177e4 LT |
1107 | |
1108 | spin_lock(&files->file_lock); | |
badf1662 DS |
1109 | fdt = files_fdtable(files); |
1110 | if (fd >= fdt->max_fds) | |
1da177e4 | 1111 | goto out_unlock; |
badf1662 | 1112 | filp = fdt->fd[fd]; |
1da177e4 LT |
1113 | if (!filp) |
1114 | goto out_unlock; | |
ab2af1f5 | 1115 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1116 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1117 | __put_unused_fd(files, fd); |
1118 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1119 | retval = filp_close(filp, files); |
1120 | ||
1121 | /* can't restart close syscall because file table entry was cleared */ | |
1122 | if (unlikely(retval == -ERESTARTSYS || | |
1123 | retval == -ERESTARTNOINTR || | |
1124 | retval == -ERESTARTNOHAND || | |
1125 | retval == -ERESTART_RESTARTBLOCK)) | |
1126 | retval = -EINTR; | |
1127 | ||
1128 | return retval; | |
1da177e4 LT |
1129 | |
1130 | out_unlock: | |
1131 | spin_unlock(&files->file_lock); | |
1132 | return -EBADF; | |
1133 | } | |
1134 | ||
1135 | EXPORT_SYMBOL(sys_close); | |
1136 | ||
1137 | /* | |
1138 | * This routine simulates a hangup on the tty, to arrange that users | |
1139 | * are given clean terminals at login time. | |
1140 | */ | |
1141 | asmlinkage long sys_vhangup(void) | |
1142 | { | |
1143 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1144 | tty_vhangup_self(); |
1da177e4 LT |
1145 | return 0; |
1146 | } | |
1147 | return -EPERM; | |
1148 | } | |
1149 | ||
1150 | /* | |
1151 | * Called when an inode is about to be open. | |
1152 | * We use this to disallow opening large files on 32bit systems if | |
1153 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1154 | * on this flag in sys_open. | |
1155 | */ | |
1156 | int generic_file_open(struct inode * inode, struct file * filp) | |
1157 | { | |
1158 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1159 | return -EOVERFLOW; |
1da177e4 LT |
1160 | return 0; |
1161 | } | |
1162 | ||
1163 | EXPORT_SYMBOL(generic_file_open); | |
1164 | ||
1165 | /* | |
1166 | * This is used by subsystems that don't want seekable | |
1167 | * file descriptors | |
1168 | */ | |
1169 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1170 | { | |
1171 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1172 | return 0; | |
1173 | } | |
1174 | ||
1175 | EXPORT_SYMBOL(nonseekable_open); |