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