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 | ||
125 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) | |
126 | { | |
127 | struct nameidata nd; | |
128 | int error; | |
129 | ||
130 | error = user_path_walk(path, &nd); | |
131 | if (!error) { | |
132 | struct statfs tmp; | |
4ac91378 | 133 | error = vfs_statfs_native(nd.path.dentry, &tmp); |
1da177e4 LT |
134 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
135 | error = -EFAULT; | |
1d957f9b | 136 | path_put(&nd.path); |
1da177e4 LT |
137 | } |
138 | return error; | |
139 | } | |
140 | ||
141 | ||
142 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) | |
143 | { | |
144 | struct nameidata nd; | |
145 | long error; | |
146 | ||
147 | if (sz != sizeof(*buf)) | |
148 | return -EINVAL; | |
149 | error = user_path_walk(path, &nd); | |
150 | if (!error) { | |
151 | struct statfs64 tmp; | |
4ac91378 | 152 | error = vfs_statfs64(nd.path.dentry, &tmp); |
1da177e4 LT |
153 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
154 | error = -EFAULT; | |
1d957f9b | 155 | path_put(&nd.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 | ||
b01ec0ef | 226 | static long do_sys_truncate(const char __user * path, loff_t length) |
1da177e4 LT |
227 | { |
228 | struct nameidata nd; | |
229 | struct inode * inode; | |
230 | int error; | |
231 | ||
232 | error = -EINVAL; | |
233 | if (length < 0) /* sorry, but loff_t says... */ | |
234 | goto out; | |
235 | ||
236 | error = user_path_walk(path, &nd); | |
237 | if (error) | |
238 | goto out; | |
4ac91378 | 239 | inode = nd.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 | ||
9ac9b847 | 250 | error = mnt_want_write(nd.path.mnt); |
1da177e4 LT |
251 | if (error) |
252 | goto dput_and_out; | |
253 | ||
9ac9b847 DH |
254 | error = vfs_permission(&nd, MAY_WRITE); |
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); | |
4ac91378 | 277 | error = do_truncate(nd.path.dentry, length, 0, NULL); |
1da177e4 | 278 | } |
1da177e4 | 279 | |
9700382c | 280 | put_write_and_out: |
281 | put_write_access(inode); | |
9ac9b847 DH |
282 | mnt_drop_write_and_out: |
283 | mnt_drop_write(nd.path.mnt); | |
1da177e4 | 284 | dput_and_out: |
1d957f9b | 285 | path_put(&nd.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 LT |
427 | { |
428 | struct nameidata nd; | |
429 | int old_fsuid, old_fsgid; | |
086f7316 | 430 | kernel_cap_t uninitialized_var(old_cap); /* !SECURE_NO_SETUID_FIXUP */ |
1da177e4 LT |
431 | int res; |
432 | ||
433 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
434 | return -EINVAL; | |
435 | ||
436 | old_fsuid = current->fsuid; | |
437 | old_fsgid = current->fsgid; | |
1da177e4 LT |
438 | |
439 | current->fsuid = current->uid; | |
440 | current->fsgid = current->gid; | |
441 | ||
086f7316 AM |
442 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
443 | /* | |
444 | * Clear the capabilities if we switch to a non-root user | |
445 | */ | |
446 | #ifndef CONFIG_SECURITY_FILE_CAPABILITIES | |
447 | /* | |
448 | * FIXME: There is a race here against sys_capset. The | |
449 | * capabilities can change yet we will restore the old | |
450 | * value below. We should hold task_capabilities_lock, | |
451 | * but we cannot because user_path_walk can sleep. | |
452 | */ | |
453 | #endif /* ndef CONFIG_SECURITY_FILE_CAPABILITIES */ | |
454 | if (current->uid) | |
455 | old_cap = cap_set_effective(__cap_empty_set); | |
456 | else | |
457 | old_cap = cap_set_effective(current->cap_permitted); | |
458 | } | |
1da177e4 | 459 | |
5590ff0d | 460 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); |
6902d925 DH |
461 | if (res) |
462 | goto out; | |
463 | ||
464 | res = vfs_permission(&nd, mode); | |
465 | /* SuS v2 requires we report a read only fs too */ | |
466 | if(res || !(mode & S_IWOTH) || | |
4ac91378 | 467 | special_file(nd.path.dentry->d_inode->i_mode)) |
6902d925 | 468 | goto out_path_release; |
2f676cbc DH |
469 | /* |
470 | * This is a rare case where using __mnt_is_readonly() | |
471 | * is OK without a mnt_want/drop_write() pair. Since | |
472 | * no actual write to the fs is performed here, we do | |
473 | * not need to telegraph to that to anyone. | |
474 | * | |
475 | * By doing this, we accept that this access is | |
476 | * inherently racy and know that the fs may change | |
477 | * state before we even see this result. | |
478 | */ | |
479 | if (__mnt_is_readonly(nd.path.mnt)) | |
6902d925 | 480 | res = -EROFS; |
1da177e4 | 481 | |
6902d925 | 482 | out_path_release: |
1d957f9b | 483 | path_put(&nd.path); |
6902d925 | 484 | out: |
1da177e4 LT |
485 | current->fsuid = old_fsuid; |
486 | current->fsgid = old_fsgid; | |
086f7316 AM |
487 | |
488 | if (!issecure(SECURE_NO_SETUID_FIXUP)) | |
489 | cap_set_effective(old_cap); | |
1da177e4 LT |
490 | |
491 | return res; | |
492 | } | |
493 | ||
5590ff0d UD |
494 | asmlinkage long sys_access(const char __user *filename, int mode) |
495 | { | |
496 | return sys_faccessat(AT_FDCWD, filename, mode); | |
497 | } | |
498 | ||
1da177e4 LT |
499 | asmlinkage long sys_chdir(const char __user * filename) |
500 | { | |
501 | struct nameidata nd; | |
502 | int error; | |
503 | ||
8bb79224 | 504 | error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd); |
1da177e4 LT |
505 | if (error) |
506 | goto out; | |
507 | ||
8bb79224 | 508 | error = vfs_permission(&nd, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
509 | if (error) |
510 | goto dput_and_out; | |
511 | ||
ac748a09 | 512 | set_fs_pwd(current->fs, &nd.path); |
1da177e4 LT |
513 | |
514 | dput_and_out: | |
1d957f9b | 515 | path_put(&nd.path); |
1da177e4 LT |
516 | out: |
517 | return error; | |
518 | } | |
519 | ||
520 | asmlinkage long sys_fchdir(unsigned int fd) | |
521 | { | |
522 | struct file *file; | |
1da177e4 | 523 | struct inode *inode; |
1da177e4 LT |
524 | int error; |
525 | ||
526 | error = -EBADF; | |
527 | file = fget(fd); | |
528 | if (!file) | |
529 | goto out; | |
530 | ||
ac748a09 | 531 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
532 | |
533 | error = -ENOTDIR; | |
534 | if (!S_ISDIR(inode->i_mode)) | |
535 | goto out_putf; | |
536 | ||
8c744fb8 | 537 | error = file_permission(file, MAY_EXEC); |
1da177e4 | 538 | if (!error) |
ac748a09 | 539 | set_fs_pwd(current->fs, &file->f_path); |
1da177e4 LT |
540 | out_putf: |
541 | fput(file); | |
542 | out: | |
543 | return error; | |
544 | } | |
545 | ||
546 | asmlinkage long sys_chroot(const char __user * filename) | |
547 | { | |
548 | struct nameidata nd; | |
549 | int error; | |
550 | ||
7f2da1e7 | 551 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd); |
1da177e4 LT |
552 | if (error) |
553 | goto out; | |
554 | ||
e4543edd | 555 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
556 | if (error) |
557 | goto dput_and_out; | |
558 | ||
559 | error = -EPERM; | |
560 | if (!capable(CAP_SYS_CHROOT)) | |
561 | goto dput_and_out; | |
562 | ||
ac748a09 | 563 | set_fs_root(current->fs, &nd.path); |
1da177e4 LT |
564 | error = 0; |
565 | dput_and_out: | |
1d957f9b | 566 | path_put(&nd.path); |
1da177e4 LT |
567 | out: |
568 | return error; | |
569 | } | |
570 | ||
571 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
572 | { | |
573 | struct inode * inode; | |
574 | struct dentry * dentry; | |
575 | struct file * file; | |
576 | int err = -EBADF; | |
577 | struct iattr newattrs; | |
578 | ||
579 | file = fget(fd); | |
580 | if (!file) | |
581 | goto out; | |
582 | ||
0f7fc9e4 | 583 | dentry = file->f_path.dentry; |
1da177e4 LT |
584 | inode = dentry->d_inode; |
585 | ||
5a190ae6 | 586 | audit_inode(NULL, dentry); |
73241ccc | 587 | |
2af482a7 DH |
588 | err = mnt_want_write(file->f_path.mnt); |
589 | if (err) | |
1da177e4 LT |
590 | goto out_putf; |
591 | err = -EPERM; | |
592 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
2af482a7 | 593 | goto out_drop_write; |
1b1dcc1b | 594 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
595 | if (mode == (mode_t) -1) |
596 | mode = inode->i_mode; | |
597 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
598 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
599 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 600 | mutex_unlock(&inode->i_mutex); |
1da177e4 | 601 | |
2af482a7 DH |
602 | out_drop_write: |
603 | mnt_drop_write(file->f_path.mnt); | |
1da177e4 LT |
604 | out_putf: |
605 | fput(file); | |
606 | out: | |
607 | return err; | |
608 | } | |
609 | ||
5590ff0d UD |
610 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
611 | mode_t mode) | |
1da177e4 LT |
612 | { |
613 | struct nameidata nd; | |
614 | struct inode * inode; | |
615 | int error; | |
616 | struct iattr newattrs; | |
617 | ||
5590ff0d | 618 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
619 | if (error) |
620 | goto out; | |
4ac91378 | 621 | inode = nd.path.dentry->d_inode; |
1da177e4 | 622 | |
2af482a7 DH |
623 | error = mnt_want_write(nd.path.mnt); |
624 | if (error) | |
1da177e4 LT |
625 | goto dput_and_out; |
626 | ||
627 | error = -EPERM; | |
628 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
2af482a7 | 629 | goto out_drop_write; |
1da177e4 | 630 | |
1b1dcc1b | 631 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
632 | if (mode == (mode_t) -1) |
633 | mode = inode->i_mode; | |
634 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
635 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
4ac91378 | 636 | error = notify_change(nd.path.dentry, &newattrs); |
1b1dcc1b | 637 | mutex_unlock(&inode->i_mutex); |
1da177e4 | 638 | |
2af482a7 DH |
639 | out_drop_write: |
640 | mnt_drop_write(nd.path.mnt); | |
1da177e4 | 641 | dput_and_out: |
1d957f9b | 642 | path_put(&nd.path); |
1da177e4 LT |
643 | out: |
644 | return error; | |
645 | } | |
646 | ||
5590ff0d UD |
647 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
648 | { | |
649 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
650 | } | |
651 | ||
1da177e4 LT |
652 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
653 | { | |
654 | struct inode * inode; | |
655 | int error; | |
656 | struct iattr newattrs; | |
657 | ||
658 | error = -ENOENT; | |
659 | if (!(inode = dentry->d_inode)) { | |
660 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
661 | goto out; | |
662 | } | |
1da177e4 LT |
663 | error = -EPERM; |
664 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
665 | goto out; | |
666 | newattrs.ia_valid = ATTR_CTIME; | |
667 | if (user != (uid_t) -1) { | |
668 | newattrs.ia_valid |= ATTR_UID; | |
669 | newattrs.ia_uid = user; | |
670 | } | |
671 | if (group != (gid_t) -1) { | |
672 | newattrs.ia_valid |= ATTR_GID; | |
673 | newattrs.ia_gid = group; | |
674 | } | |
675 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
676 | newattrs.ia_valid |= |
677 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
1b1dcc1b | 678 | mutex_lock(&inode->i_mutex); |
1da177e4 | 679 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 680 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
681 | out: |
682 | return error; | |
683 | } | |
684 | ||
685 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
686 | { | |
687 | struct nameidata nd; | |
688 | int error; | |
689 | ||
690 | error = user_path_walk(filename, &nd); | |
6902d925 DH |
691 | if (error) |
692 | goto out; | |
2af482a7 DH |
693 | error = mnt_want_write(nd.path.mnt); |
694 | if (error) | |
695 | goto out_release; | |
4ac91378 | 696 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
697 | mnt_drop_write(nd.path.mnt); |
698 | out_release: | |
1d957f9b | 699 | path_put(&nd.path); |
6902d925 | 700 | out: |
1da177e4 LT |
701 | return error; |
702 | } | |
703 | ||
5590ff0d UD |
704 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
705 | gid_t group, int flag) | |
706 | { | |
707 | struct nameidata nd; | |
708 | int error = -EINVAL; | |
709 | int follow; | |
710 | ||
711 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
712 | goto out; | |
713 | ||
714 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
715 | error = __user_walk_fd(dfd, filename, follow, &nd); | |
6902d925 DH |
716 | if (error) |
717 | goto out; | |
2af482a7 DH |
718 | error = mnt_want_write(nd.path.mnt); |
719 | if (error) | |
720 | goto out_release; | |
4ac91378 | 721 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
722 | mnt_drop_write(nd.path.mnt); |
723 | out_release: | |
1d957f9b | 724 | path_put(&nd.path); |
5590ff0d UD |
725 | out: |
726 | return error; | |
727 | } | |
728 | ||
1da177e4 LT |
729 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
730 | { | |
731 | struct nameidata nd; | |
732 | int error; | |
733 | ||
734 | error = user_path_walk_link(filename, &nd); | |
6902d925 DH |
735 | if (error) |
736 | goto out; | |
2af482a7 DH |
737 | error = mnt_want_write(nd.path.mnt); |
738 | if (error) | |
739 | goto out_release; | |
4ac91378 | 740 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
741 | mnt_drop_write(nd.path.mnt); |
742 | out_release: | |
1d957f9b | 743 | path_put(&nd.path); |
6902d925 | 744 | out: |
1da177e4 LT |
745 | return error; |
746 | } | |
747 | ||
748 | ||
749 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
750 | { | |
751 | struct file * file; | |
752 | int error = -EBADF; | |
6902d925 | 753 | struct dentry * dentry; |
1da177e4 LT |
754 | |
755 | file = fget(fd); | |
6902d925 DH |
756 | if (!file) |
757 | goto out; | |
758 | ||
2af482a7 DH |
759 | error = mnt_want_write(file->f_path.mnt); |
760 | if (error) | |
761 | goto out_fput; | |
0f7fc9e4 | 762 | dentry = file->f_path.dentry; |
5a190ae6 | 763 | audit_inode(NULL, dentry); |
6902d925 | 764 | error = chown_common(dentry, user, group); |
2af482a7 DH |
765 | mnt_drop_write(file->f_path.mnt); |
766 | out_fput: | |
6902d925 DH |
767 | fput(file); |
768 | out: | |
1da177e4 LT |
769 | return error; |
770 | } | |
771 | ||
4a3fd211 DH |
772 | /* |
773 | * You have to be very careful that these write | |
774 | * counts get cleaned up in error cases and | |
775 | * upon __fput(). This should probably never | |
776 | * be called outside of __dentry_open(). | |
777 | */ | |
778 | static inline int __get_file_write_access(struct inode *inode, | |
779 | struct vfsmount *mnt) | |
780 | { | |
781 | int error; | |
782 | error = get_write_access(inode); | |
783 | if (error) | |
784 | return error; | |
785 | /* | |
786 | * Do not take mount writer counts on | |
787 | * special files since no writes to | |
788 | * the mount itself will occur. | |
789 | */ | |
790 | if (!special_file(inode->i_mode)) { | |
791 | /* | |
792 | * Balanced in __fput() | |
793 | */ | |
794 | error = mnt_want_write(mnt); | |
795 | if (error) | |
796 | put_write_access(inode); | |
797 | } | |
798 | return error; | |
799 | } | |
800 | ||
a1a5b3d9 | 801 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
802 | int flags, struct file *f, |
803 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 804 | { |
1da177e4 LT |
805 | struct inode *inode; |
806 | int error; | |
807 | ||
1da177e4 | 808 | f->f_flags = flags; |
a1a5b3d9 PS |
809 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
810 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
811 | inode = dentry->d_inode; |
812 | if (f->f_mode & FMODE_WRITE) { | |
4a3fd211 | 813 | error = __get_file_write_access(inode, mnt); |
1da177e4 LT |
814 | if (error) |
815 | goto cleanup_file; | |
ad775f5a DH |
816 | if (!special_file(inode->i_mode)) |
817 | file_take_write(f); | |
1da177e4 LT |
818 | } |
819 | ||
820 | f->f_mapping = inode->i_mapping; | |
0f7fc9e4 JJS |
821 | f->f_path.dentry = dentry; |
822 | f->f_path.mnt = mnt; | |
1da177e4 LT |
823 | f->f_pos = 0; |
824 | f->f_op = fops_get(inode->i_fop); | |
825 | file_move(f, &inode->i_sb->s_files); | |
826 | ||
788e7dd4 YN |
827 | error = security_dentry_open(f); |
828 | if (error) | |
829 | goto cleanup_all; | |
830 | ||
834f2a4a TM |
831 | if (!open && f->f_op) |
832 | open = f->f_op->open; | |
833 | if (open) { | |
834 | error = open(inode, f); | |
1da177e4 LT |
835 | if (error) |
836 | goto cleanup_all; | |
837 | } | |
834f2a4a | 838 | |
1da177e4 LT |
839 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
840 | ||
841 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
842 | ||
843 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
844 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
845 | if (!f->f_mapping->a_ops || |
846 | ((!f->f_mapping->a_ops->direct_IO) && | |
70688e4d | 847 | (!f->f_mapping->a_ops->get_xip_mem))) { |
1da177e4 LT |
848 | fput(f); |
849 | f = ERR_PTR(-EINVAL); | |
850 | } | |
851 | } | |
852 | ||
853 | return f; | |
854 | ||
855 | cleanup_all: | |
856 | fops_put(f->f_op); | |
4a3fd211 | 857 | if (f->f_mode & FMODE_WRITE) { |
1da177e4 | 858 | put_write_access(inode); |
ad775f5a DH |
859 | if (!special_file(inode->i_mode)) { |
860 | /* | |
861 | * We don't consider this a real | |
862 | * mnt_want/drop_write() pair | |
863 | * because it all happenend right | |
864 | * here, so just reset the state. | |
865 | */ | |
866 | file_reset_write(f); | |
4a3fd211 | 867 | mnt_drop_write(mnt); |
ad775f5a | 868 | } |
4a3fd211 | 869 | } |
1da177e4 | 870 | file_kill(f); |
0f7fc9e4 JJS |
871 | f->f_path.dentry = NULL; |
872 | f->f_path.mnt = NULL; | |
1da177e4 LT |
873 | cleanup_file: |
874 | put_filp(f); | |
1da177e4 LT |
875 | dput(dentry); |
876 | mntput(mnt); | |
877 | return ERR_PTR(error); | |
878 | } | |
879 | ||
834f2a4a TM |
880 | /** |
881 | * lookup_instantiate_filp - instantiates the open intent filp | |
882 | * @nd: pointer to nameidata | |
883 | * @dentry: pointer to dentry | |
884 | * @open: open callback | |
885 | * | |
886 | * Helper for filesystems that want to use lookup open intents and pass back | |
887 | * a fully instantiated struct file to the caller. | |
888 | * This function is meant to be called from within a filesystem's | |
889 | * lookup method. | |
9a56c213 OD |
890 | * Beware of calling it for non-regular files! Those ->open methods might block |
891 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
892 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
893 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
894 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
895 | * path information remains valid. | |
896 | * If the open callback is set to NULL, then the standard f_op->open() | |
897 | * filesystem callback is substituted. | |
898 | */ | |
899 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
900 | int (*open)(struct inode *, struct file *)) | |
901 | { | |
902 | if (IS_ERR(nd->intent.open.file)) | |
903 | goto out; | |
904 | if (IS_ERR(dentry)) | |
905 | goto out_err; | |
4ac91378 | 906 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
834f2a4a TM |
907 | nd->intent.open.flags - 1, |
908 | nd->intent.open.file, | |
909 | open); | |
910 | out: | |
911 | return nd->intent.open.file; | |
912 | out_err: | |
913 | release_open_intent(nd); | |
914 | nd->intent.open.file = (struct file *)dentry; | |
915 | goto out; | |
916 | } | |
917 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
918 | ||
919 | /** | |
920 | * nameidata_to_filp - convert a nameidata to an open filp. | |
921 | * @nd: pointer to nameidata | |
922 | * @flags: open flags | |
923 | * | |
924 | * Note that this function destroys the original nameidata | |
925 | */ | |
926 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
927 | { | |
928 | struct file *filp; | |
929 | ||
930 | /* Pick up the filp from the open intent */ | |
931 | filp = nd->intent.open.file; | |
932 | /* Has the filesystem initialised the file for us? */ | |
0f7fc9e4 | 933 | if (filp->f_path.dentry == NULL) |
4ac91378 JB |
934 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
935 | NULL); | |
834f2a4a | 936 | else |
1d957f9b | 937 | path_put(&nd->path); |
834f2a4a TM |
938 | return filp; |
939 | } | |
940 | ||
6fdcc216 PS |
941 | /* |
942 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
943 | * error. | |
944 | */ | |
a1a5b3d9 PS |
945 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
946 | { | |
947 | int error; | |
948 | struct file *f; | |
949 | ||
322ee5b3 CH |
950 | /* |
951 | * We must always pass in a valid mount pointer. Historically | |
952 | * callers got away with not passing it, but we must enforce this at | |
953 | * the earliest possible point now to avoid strange problems deep in the | |
954 | * filesystem stack. | |
955 | */ | |
956 | if (!mnt) { | |
957 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); | |
958 | dump_stack(); | |
959 | return ERR_PTR(-EINVAL); | |
960 | } | |
961 | ||
a1a5b3d9 PS |
962 | error = -ENFILE; |
963 | f = get_empty_filp(); | |
6fdcc216 PS |
964 | if (f == NULL) { |
965 | dput(dentry); | |
966 | mntput(mnt); | |
a1a5b3d9 | 967 | return ERR_PTR(error); |
6fdcc216 | 968 | } |
a1a5b3d9 | 969 | |
834f2a4a | 970 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 971 | } |
1da177e4 LT |
972 | EXPORT_SYMBOL(dentry_open); |
973 | ||
974 | /* | |
975 | * Find an empty file descriptor entry, and mark it busy. | |
976 | */ | |
4a19542e | 977 | int get_unused_fd_flags(int flags) |
1da177e4 LT |
978 | { |
979 | struct files_struct * files = current->files; | |
980 | int fd, error; | |
badf1662 | 981 | struct fdtable *fdt; |
1da177e4 LT |
982 | |
983 | error = -EMFILE; | |
984 | spin_lock(&files->file_lock); | |
985 | ||
986 | repeat: | |
badf1662 | 987 | fdt = files_fdtable(files); |
bbea9f69 | 988 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds, |
0c9e63fd | 989 | files->next_fd); |
1da177e4 LT |
990 | |
991 | /* | |
992 | * N.B. For clone tasks sharing a files structure, this test | |
993 | * will limit the total number of files that can be opened. | |
994 | */ | |
995 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
996 | goto out; | |
997 | ||
998 | /* Do we need to expand the fd array or fd set? */ | |
999 | error = expand_files(files, fd); | |
1000 | if (error < 0) | |
1001 | goto out; | |
1002 | ||
1003 | if (error) { | |
1004 | /* | |
1005 | * If we needed to expand the fs array we | |
1006 | * might have blocked - try again. | |
1007 | */ | |
1008 | error = -EMFILE; | |
1009 | goto repeat; | |
1010 | } | |
1011 | ||
badf1662 | 1012 | FD_SET(fd, fdt->open_fds); |
f23513e8 UD |
1013 | if (flags & O_CLOEXEC) |
1014 | FD_SET(fd, fdt->close_on_exec); | |
1015 | else | |
1016 | FD_CLR(fd, fdt->close_on_exec); | |
0c9e63fd | 1017 | files->next_fd = fd + 1; |
1da177e4 LT |
1018 | #if 1 |
1019 | /* Sanity check */ | |
badf1662 | 1020 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 1021 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 1022 | fdt->fd[fd] = NULL; |
1da177e4 LT |
1023 | } |
1024 | #endif | |
1025 | error = fd; | |
1026 | ||
1027 | out: | |
1028 | spin_unlock(&files->file_lock); | |
1029 | return error; | |
1030 | } | |
1031 | ||
f23513e8 UD |
1032 | int get_unused_fd(void) |
1033 | { | |
1034 | return get_unused_fd_flags(0); | |
1035 | } | |
1036 | ||
1da177e4 LT |
1037 | EXPORT_SYMBOL(get_unused_fd); |
1038 | ||
b01ec0ef | 1039 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 1040 | { |
badf1662 DS |
1041 | struct fdtable *fdt = files_fdtable(files); |
1042 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
1043 | if (fd < files->next_fd) |
1044 | files->next_fd = fd; | |
1da177e4 LT |
1045 | } |
1046 | ||
fc9b52cd | 1047 | void put_unused_fd(unsigned int fd) |
1da177e4 LT |
1048 | { |
1049 | struct files_struct *files = current->files; | |
1050 | spin_lock(&files->file_lock); | |
1051 | __put_unused_fd(files, fd); | |
1052 | spin_unlock(&files->file_lock); | |
1053 | } | |
1054 | ||
1055 | EXPORT_SYMBOL(put_unused_fd); | |
1056 | ||
1057 | /* | |
5590ff0d | 1058 | * Install a file pointer in the fd array. |
1da177e4 LT |
1059 | * |
1060 | * The VFS is full of places where we drop the files lock between | |
1061 | * setting the open_fds bitmap and installing the file in the file | |
1062 | * array. At any such point, we are vulnerable to a dup2() race | |
1063 | * installing a file in the array before us. We need to detect this and | |
1064 | * fput() the struct file we are about to overwrite in this case. | |
1065 | * | |
1066 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
1067 | * will follow. | |
1068 | */ | |
1069 | ||
fc9b52cd | 1070 | void fd_install(unsigned int fd, struct file *file) |
1da177e4 LT |
1071 | { |
1072 | struct files_struct *files = current->files; | |
badf1662 | 1073 | struct fdtable *fdt; |
1da177e4 | 1074 | spin_lock(&files->file_lock); |
badf1662 | 1075 | fdt = files_fdtable(files); |
ab2af1f5 DS |
1076 | BUG_ON(fdt->fd[fd] != NULL); |
1077 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
1078 | spin_unlock(&files->file_lock); |
1079 | } | |
1080 | ||
1081 | EXPORT_SYMBOL(fd_install); | |
1082 | ||
5590ff0d | 1083 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 1084 | { |
e922efc3 MS |
1085 | char *tmp = getname(filename); |
1086 | int fd = PTR_ERR(tmp); | |
1da177e4 | 1087 | |
1da177e4 | 1088 | if (!IS_ERR(tmp)) { |
f23513e8 | 1089 | fd = get_unused_fd_flags(flags); |
1da177e4 | 1090 | if (fd >= 0) { |
5590ff0d | 1091 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
1092 | if (IS_ERR(f)) { |
1093 | put_unused_fd(fd); | |
1094 | fd = PTR_ERR(f); | |
1095 | } else { | |
0f7fc9e4 | 1096 | fsnotify_open(f->f_path.dentry); |
fed2fc18 TN |
1097 | fd_install(fd, f); |
1098 | } | |
1da177e4 | 1099 | } |
1da177e4 LT |
1100 | putname(tmp); |
1101 | } | |
1102 | return fd; | |
1da177e4 | 1103 | } |
e922efc3 MS |
1104 | |
1105 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
1106 | { | |
385910f2 LT |
1107 | long ret; |
1108 | ||
e922efc3 MS |
1109 | if (force_o_largefile()) |
1110 | flags |= O_LARGEFILE; | |
1111 | ||
385910f2 LT |
1112 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
1113 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1114 | asmlinkage_protect(3, ret, filename, flags, mode); |
385910f2 | 1115 | return ret; |
e922efc3 | 1116 | } |
1da177e4 | 1117 | |
5590ff0d UD |
1118 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
1119 | int mode) | |
1120 | { | |
385910f2 LT |
1121 | long ret; |
1122 | ||
5590ff0d UD |
1123 | if (force_o_largefile()) |
1124 | flags |= O_LARGEFILE; | |
1125 | ||
385910f2 LT |
1126 | ret = do_sys_open(dfd, filename, flags, mode); |
1127 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1128 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
385910f2 | 1129 | return ret; |
5590ff0d | 1130 | } |
5590ff0d | 1131 | |
1da177e4 LT |
1132 | #ifndef __alpha__ |
1133 | ||
1134 | /* | |
1135 | * For backward compatibility? Maybe this should be moved | |
1136 | * into arch/i386 instead? | |
1137 | */ | |
1138 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1139 | { | |
1140 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1141 | } | |
1142 | ||
1143 | #endif | |
1144 | ||
1145 | /* | |
1146 | * "id" is the POSIX thread ID. We use the | |
1147 | * files pointer for this.. | |
1148 | */ | |
1149 | int filp_close(struct file *filp, fl_owner_t id) | |
1150 | { | |
45778ca8 | 1151 | int retval = 0; |
1da177e4 LT |
1152 | |
1153 | if (!file_count(filp)) { | |
1154 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1155 | return 0; |
1da177e4 LT |
1156 | } |
1157 | ||
45778ca8 | 1158 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1159 | retval = filp->f_op->flush(filp, id); |
1da177e4 LT |
1160 | |
1161 | dnotify_flush(filp, id); | |
1162 | locks_remove_posix(filp, id); | |
1163 | fput(filp); | |
1164 | return retval; | |
1165 | } | |
1166 | ||
1167 | EXPORT_SYMBOL(filp_close); | |
1168 | ||
1169 | /* | |
1170 | * Careful here! We test whether the file pointer is NULL before | |
1171 | * releasing the fd. This ensures that one clone task can't release | |
1172 | * an fd while another clone is opening it. | |
1173 | */ | |
1174 | asmlinkage long sys_close(unsigned int fd) | |
1175 | { | |
1176 | struct file * filp; | |
1177 | struct files_struct *files = current->files; | |
badf1662 | 1178 | struct fdtable *fdt; |
ee731f4f | 1179 | int retval; |
1da177e4 LT |
1180 | |
1181 | spin_lock(&files->file_lock); | |
badf1662 DS |
1182 | fdt = files_fdtable(files); |
1183 | if (fd >= fdt->max_fds) | |
1da177e4 | 1184 | goto out_unlock; |
badf1662 | 1185 | filp = fdt->fd[fd]; |
1da177e4 LT |
1186 | if (!filp) |
1187 | goto out_unlock; | |
ab2af1f5 | 1188 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1189 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1190 | __put_unused_fd(files, fd); |
1191 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1192 | retval = filp_close(filp, files); |
1193 | ||
1194 | /* can't restart close syscall because file table entry was cleared */ | |
1195 | if (unlikely(retval == -ERESTARTSYS || | |
1196 | retval == -ERESTARTNOINTR || | |
1197 | retval == -ERESTARTNOHAND || | |
1198 | retval == -ERESTART_RESTARTBLOCK)) | |
1199 | retval = -EINTR; | |
1200 | ||
1201 | return retval; | |
1da177e4 LT |
1202 | |
1203 | out_unlock: | |
1204 | spin_unlock(&files->file_lock); | |
1205 | return -EBADF; | |
1206 | } | |
1207 | ||
1208 | EXPORT_SYMBOL(sys_close); | |
1209 | ||
1210 | /* | |
1211 | * This routine simulates a hangup on the tty, to arrange that users | |
1212 | * are given clean terminals at login time. | |
1213 | */ | |
1214 | asmlinkage long sys_vhangup(void) | |
1215 | { | |
1216 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
24ec839c | 1217 | /* XXX: this needs locking */ |
1da177e4 LT |
1218 | tty_vhangup(current->signal->tty); |
1219 | return 0; | |
1220 | } | |
1221 | return -EPERM; | |
1222 | } | |
1223 | ||
1224 | /* | |
1225 | * Called when an inode is about to be open. | |
1226 | * We use this to disallow opening large files on 32bit systems if | |
1227 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1228 | * on this flag in sys_open. | |
1229 | */ | |
1230 | int generic_file_open(struct inode * inode, struct file * filp) | |
1231 | { | |
1232 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1233 | return -EOVERFLOW; |
1da177e4 LT |
1234 | return 0; |
1235 | } | |
1236 | ||
1237 | EXPORT_SYMBOL(generic_file_open); | |
1238 | ||
1239 | /* | |
1240 | * This is used by subsystems that don't want seekable | |
1241 | * file descriptors | |
1242 | */ | |
1243 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1244 | { | |
1245 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1246 | return 0; | |
1247 | } | |
1248 | ||
1249 | EXPORT_SYMBOL(nonseekable_open); |