blob: 70e0230d8e77b79a5becb1cecece91e95a062a2e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
9#include <linux/utime.h>
10#include <linux/file.h>
11#include <linux/smp_lock.h>
12#include <linux/quotaops.h>
Robert Love0eeca282005-07-12 17:06:03 -040013#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/tty.h>
17#include <linux/namei.h>
18#include <linux/backing-dev.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080019#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/security.h>
21#include <linux/mount.h>
22#include <linux/vfs.h>
Ulrich Drepper5590ff02006-01-18 17:43:53 -080023#include <linux/fcntl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25#include <linux/fs.h>
Yoav Zachef3daed2005-06-23 00:09:58 -070026#include <linux/personality.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/pagemap.h>
28#include <linux/syscalls.h>
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -070029#include <linux/rcupdate.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31#include <asm/unistd.h>
32
33int vfs_statfs(struct super_block *sb, struct kstatfs *buf)
34{
35 int retval = -ENODEV;
36
37 if (sb) {
38 retval = -ENOSYS;
39 if (sb->s_op->statfs) {
40 memset(buf, 0, sizeof(*buf));
41 retval = security_sb_statfs(sb);
42 if (retval)
43 return retval;
44 retval = sb->s_op->statfs(sb, buf);
45 if (retval == 0 && buf->f_frsize == 0)
46 buf->f_frsize = buf->f_bsize;
47 }
48 }
49 return retval;
50}
51
52EXPORT_SYMBOL(vfs_statfs);
53
54static int vfs_statfs_native(struct super_block *sb, struct statfs *buf)
55{
56 struct kstatfs st;
57 int retval;
58
59 retval = vfs_statfs(sb, &st);
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) {
67 if ((st.f_blocks | st.f_bfree | st.f_bavail) &
68 0xffffffff00000000ULL)
69 return -EOVERFLOW;
70 /*
71 * f_files and f_ffree may be -1; it's okay to stuff
72 * that into 32 bits
73 */
74 if (st.f_files != -1 &&
75 (st.f_files & 0xffffffff00000000ULL))
76 return -EOVERFLOW;
77 if (st.f_ffree != -1 &&
78 (st.f_ffree & 0xffffffff00000000ULL))
79 return -EOVERFLOW;
80 }
81
82 buf->f_type = st.f_type;
83 buf->f_bsize = st.f_bsize;
84 buf->f_blocks = st.f_blocks;
85 buf->f_bfree = st.f_bfree;
86 buf->f_bavail = st.f_bavail;
87 buf->f_files = st.f_files;
88 buf->f_ffree = st.f_ffree;
89 buf->f_fsid = st.f_fsid;
90 buf->f_namelen = st.f_namelen;
91 buf->f_frsize = st.f_frsize;
92 memset(buf->f_spare, 0, sizeof(buf->f_spare));
93 }
94 return 0;
95}
96
97static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf)
98{
99 struct kstatfs st;
100 int retval;
101
102 retval = vfs_statfs(sb, &st);
103 if (retval)
104 return retval;
105
106 if (sizeof(*buf) == sizeof(st))
107 memcpy(buf, &st, sizeof(st));
108 else {
109 buf->f_type = st.f_type;
110 buf->f_bsize = st.f_bsize;
111 buf->f_blocks = st.f_blocks;
112 buf->f_bfree = st.f_bfree;
113 buf->f_bavail = st.f_bavail;
114 buf->f_files = st.f_files;
115 buf->f_ffree = st.f_ffree;
116 buf->f_fsid = st.f_fsid;
117 buf->f_namelen = st.f_namelen;
118 buf->f_frsize = st.f_frsize;
119 memset(buf->f_spare, 0, sizeof(buf->f_spare));
120 }
121 return 0;
122}
123
124asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
125{
126 struct nameidata nd;
127 int error;
128
129 error = user_path_walk(path, &nd);
130 if (!error) {
131 struct statfs tmp;
132 error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp);
133 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
134 error = -EFAULT;
135 path_release(&nd);
136 }
137 return error;
138}
139
140
141asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf)
142{
143 struct nameidata nd;
144 long error;
145
146 if (sz != sizeof(*buf))
147 return -EINVAL;
148 error = user_path_walk(path, &nd);
149 if (!error) {
150 struct statfs64 tmp;
151 error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp);
152 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
153 error = -EFAULT;
154 path_release(&nd);
155 }
156 return error;
157}
158
159
160asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf)
161{
162 struct file * file;
163 struct statfs tmp;
164 int error;
165
166 error = -EBADF;
167 file = fget(fd);
168 if (!file)
169 goto out;
170 error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp);
171 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
172 error = -EFAULT;
173 fput(file);
174out:
175 return error;
176}
177
178asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf)
179{
180 struct file * file;
181 struct statfs64 tmp;
182 int error;
183
184 if (sz != sizeof(*buf))
185 return -EINVAL;
186
187 error = -EBADF;
188 file = fget(fd);
189 if (!file)
190 goto out;
191 error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp);
192 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
193 error = -EFAULT;
194 fput(file);
195out:
196 return error;
197}
198
NeilBrown4a301312006-01-08 01:02:39 -0800199int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
200 struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201{
202 int err;
203 struct iattr newattrs;
204
205 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
206 if (length < 0)
207 return -EINVAL;
208
209 newattrs.ia_size = length;
NeilBrown4a301312006-01-08 01:02:39 -0800210 newattrs.ia_valid = ATTR_SIZE | time_attrs;
Miklos Szeredicc4e69d2005-11-07 00:59:49 -0800211 if (filp) {
212 newattrs.ia_file = filp;
213 newattrs.ia_valid |= ATTR_FILE;
214 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800216 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800218 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 return err;
220}
221
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800222static long do_sys_truncate(const char __user * path, loff_t length)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223{
224 struct nameidata nd;
225 struct inode * inode;
226 int error;
227
228 error = -EINVAL;
229 if (length < 0) /* sorry, but loff_t says... */
230 goto out;
231
232 error = user_path_walk(path, &nd);
233 if (error)
234 goto out;
235 inode = nd.dentry->d_inode;
236
237 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
238 error = -EISDIR;
239 if (S_ISDIR(inode->i_mode))
240 goto dput_and_out;
241
242 error = -EINVAL;
243 if (!S_ISREG(inode->i_mode))
244 goto dput_and_out;
245
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800246 error = vfs_permission(&nd, MAY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 if (error)
248 goto dput_and_out;
249
250 error = -EROFS;
251 if (IS_RDONLY(inode))
252 goto dput_and_out;
253
254 error = -EPERM;
255 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
256 goto dput_and_out;
257
258 /*
259 * Make sure that there are no leases.
260 */
261 error = break_lease(inode, FMODE_WRITE);
262 if (error)
263 goto dput_and_out;
264
265 error = get_write_access(inode);
266 if (error)
267 goto dput_and_out;
268
269 error = locks_verify_truncate(inode, NULL, length);
270 if (!error) {
271 DQUOT_INIT(inode);
NeilBrown4a301312006-01-08 01:02:39 -0800272 error = do_truncate(nd.dentry, length, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 }
274 put_write_access(inode);
275
276dput_and_out:
277 path_release(&nd);
278out:
279 return error;
280}
281
282asmlinkage long sys_truncate(const char __user * path, unsigned long length)
283{
284 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
285 return do_sys_truncate(path, (long)length);
286}
287
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800288static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
290 struct inode * inode;
291 struct dentry *dentry;
292 struct file * file;
293 int error;
294
295 error = -EINVAL;
296 if (length < 0)
297 goto out;
298 error = -EBADF;
299 file = fget(fd);
300 if (!file)
301 goto out;
302
303 /* explicitly opened as large or we are on 64-bit box */
304 if (file->f_flags & O_LARGEFILE)
305 small = 0;
306
307 dentry = file->f_dentry;
308 inode = dentry->d_inode;
309 error = -EINVAL;
310 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
311 goto out_putf;
312
313 error = -EINVAL;
314 /* Cannot ftruncate over 2^31 bytes without large file support */
315 if (small && length > MAX_NON_LFS)
316 goto out_putf;
317
318 error = -EPERM;
319 if (IS_APPEND(inode))
320 goto out_putf;
321
322 error = locks_verify_truncate(inode, file, length);
323 if (!error)
NeilBrown4a301312006-01-08 01:02:39 -0800324 error = do_truncate(dentry, length, 0, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325out_putf:
326 fput(file);
327out:
328 return error;
329}
330
331asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
332{
333 return do_sys_ftruncate(fd, length, 1);
334}
335
336/* LFS versions of truncate are only needed on 32 bit machines */
337#if BITS_PER_LONG == 32
338asmlinkage long sys_truncate64(const char __user * path, loff_t length)
339{
340 return do_sys_truncate(path, length);
341}
342
343asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
344{
345 return do_sys_ftruncate(fd, length, 0);
346}
347#endif
348
349#ifdef __ARCH_WANT_SYS_UTIME
350
351/*
352 * sys_utime() can be implemented in user-level using sys_utimes().
353 * Is this for backwards compatibility? If so, why not move it
354 * into the appropriate arch directory (for those architectures that
355 * need it).
356 */
357
358/* If times==NULL, set access and modification to current time,
359 * must be owner or have write permission.
360 * Else, update from *times, must be owner or super user.
361 */
362asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times)
363{
364 int error;
365 struct nameidata nd;
366 struct inode * inode;
367 struct iattr newattrs;
368
369 error = user_path_walk(filename, &nd);
370 if (error)
371 goto out;
372 inode = nd.dentry->d_inode;
373
374 error = -EROFS;
375 if (IS_RDONLY(inode))
376 goto dput_and_out;
377
378 /* Don't worry, the checks are done in inode_change_ok() */
379 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
380 if (times) {
381 error = -EPERM;
382 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
383 goto dput_and_out;
384
385 error = get_user(newattrs.ia_atime.tv_sec, &times->actime);
386 newattrs.ia_atime.tv_nsec = 0;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800387 if (!error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 error = get_user(newattrs.ia_mtime.tv_sec, &times->modtime);
389 newattrs.ia_mtime.tv_nsec = 0;
390 if (error)
391 goto dput_and_out;
392
393 newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
394 } else {
395 error = -EACCES;
396 if (IS_IMMUTABLE(inode))
397 goto dput_and_out;
398
399 if (current->fsuid != inode->i_uid &&
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800400 (error = vfs_permission(&nd, MAY_WRITE)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 goto dput_and_out;
402 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800403 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 error = notify_change(nd.dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800405 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406dput_and_out:
407 path_release(&nd);
408out:
409 return error;
410}
411
412#endif
413
414/* If times==NULL, set access and modification to current time,
415 * must be owner or have write permission.
416 * Else, update from *times, must be owner or super user.
417 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800418long do_utimes(int dfd, char __user *filename, struct timeval *times)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419{
420 int error;
421 struct nameidata nd;
422 struct inode * inode;
423 struct iattr newattrs;
424
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800425 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 if (error)
428 goto out;
429 inode = nd.dentry->d_inode;
430
431 error = -EROFS;
432 if (IS_RDONLY(inode))
433 goto dput_and_out;
434
435 /* Don't worry, the checks are done in inode_change_ok() */
436 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
437 if (times) {
438 error = -EPERM;
439 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
440 goto dput_and_out;
441
442 newattrs.ia_atime.tv_sec = times[0].tv_sec;
443 newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000;
444 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
445 newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000;
446 newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
447 } else {
448 error = -EACCES;
449 if (IS_IMMUTABLE(inode))
450 goto dput_and_out;
451
452 if (current->fsuid != inode->i_uid &&
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800453 (error = vfs_permission(&nd, MAY_WRITE)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 goto dput_and_out;
455 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800456 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 error = notify_change(nd.dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800458 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459dput_and_out:
460 path_release(&nd);
461out:
462 return error;
463}
464
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800465asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466{
467 struct timeval times[2];
468
469 if (utimes && copy_from_user(&times, utimes, sizeof(times)))
470 return -EFAULT;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800471 return do_utimes(dfd, filename, utimes ? times : NULL);
472}
473
474asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes)
475{
476 return sys_futimesat(AT_FDCWD, filename, utimes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477}
478
479
480/*
481 * access() needs to use the real uid/gid, not the effective uid/gid.
482 * We do this by temporarily clearing all FS-related capabilities and
483 * switching the fsuid/fsgid around to the real ones.
484 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800485asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486{
487 struct nameidata nd;
488 int old_fsuid, old_fsgid;
489 kernel_cap_t old_cap;
490 int res;
491
492 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
493 return -EINVAL;
494
495 old_fsuid = current->fsuid;
496 old_fsgid = current->fsgid;
497 old_cap = current->cap_effective;
498
499 current->fsuid = current->uid;
500 current->fsgid = current->gid;
501
502 /*
503 * Clear the capabilities if we switch to a non-root user
504 *
505 * FIXME: There is a race here against sys_capset. The
506 * capabilities can change yet we will restore the old
507 * value below. We should hold task_capabilities_lock,
508 * but we cannot because user_path_walk can sleep.
509 */
510 if (current->uid)
511 cap_clear(current->cap_effective);
512 else
513 current->cap_effective = current->cap_permitted;
514
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800515 res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 if (!res) {
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800517 res = vfs_permission(&nd, mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 /* SuS v2 requires we report a read only fs too */
519 if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode)
520 && !special_file(nd.dentry->d_inode->i_mode))
521 res = -EROFS;
522 path_release(&nd);
523 }
524
525 current->fsuid = old_fsuid;
526 current->fsgid = old_fsgid;
527 current->cap_effective = old_cap;
528
529 return res;
530}
531
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800532asmlinkage long sys_access(const char __user *filename, int mode)
533{
534 return sys_faccessat(AT_FDCWD, filename, mode);
535}
536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537asmlinkage long sys_chdir(const char __user * filename)
538{
539 struct nameidata nd;
540 int error;
541
542 error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd);
543 if (error)
544 goto out;
545
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800546 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 if (error)
548 goto dput_and_out;
549
550 set_fs_pwd(current->fs, nd.mnt, nd.dentry);
551
552dput_and_out:
553 path_release(&nd);
554out:
555 return error;
556}
557
558asmlinkage long sys_fchdir(unsigned int fd)
559{
560 struct file *file;
561 struct dentry *dentry;
562 struct inode *inode;
563 struct vfsmount *mnt;
564 int error;
565
566 error = -EBADF;
567 file = fget(fd);
568 if (!file)
569 goto out;
570
571 dentry = file->f_dentry;
572 mnt = file->f_vfsmnt;
573 inode = dentry->d_inode;
574
575 error = -ENOTDIR;
576 if (!S_ISDIR(inode->i_mode))
577 goto out_putf;
578
Christoph Hellwig8c744fb2005-11-08 21:35:04 -0800579 error = file_permission(file, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 if (!error)
581 set_fs_pwd(current->fs, mnt, dentry);
582out_putf:
583 fput(file);
584out:
585 return error;
586}
587
588asmlinkage long sys_chroot(const char __user * filename)
589{
590 struct nameidata nd;
591 int error;
592
593 error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
594 if (error)
595 goto out;
596
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800597 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 if (error)
599 goto dput_and_out;
600
601 error = -EPERM;
602 if (!capable(CAP_SYS_CHROOT))
603 goto dput_and_out;
604
605 set_fs_root(current->fs, nd.mnt, nd.dentry);
606 set_fs_altroot();
607 error = 0;
608dput_and_out:
609 path_release(&nd);
610out:
611 return error;
612}
613
614asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
615{
616 struct inode * inode;
617 struct dentry * dentry;
618 struct file * file;
619 int err = -EBADF;
620 struct iattr newattrs;
621
622 file = fget(fd);
623 if (!file)
624 goto out;
625
626 dentry = file->f_dentry;
627 inode = dentry->d_inode;
628
629 err = -EROFS;
630 if (IS_RDONLY(inode))
631 goto out_putf;
632 err = -EPERM;
633 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
634 goto out_putf;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800635 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if (mode == (mode_t) -1)
637 mode = inode->i_mode;
638 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
639 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
640 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800641 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643out_putf:
644 fput(file);
645out:
646 return err;
647}
648
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800649asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
650 mode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651{
652 struct nameidata nd;
653 struct inode * inode;
654 int error;
655 struct iattr newattrs;
656
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800657 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 if (error)
659 goto out;
660 inode = nd.dentry->d_inode;
661
662 error = -EROFS;
663 if (IS_RDONLY(inode))
664 goto dput_and_out;
665
666 error = -EPERM;
667 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
668 goto dput_and_out;
669
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800670 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 if (mode == (mode_t) -1)
672 mode = inode->i_mode;
673 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
674 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
675 error = notify_change(nd.dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800676 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678dput_and_out:
679 path_release(&nd);
680out:
681 return error;
682}
683
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800684asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
685{
686 return sys_fchmodat(AT_FDCWD, filename, mode);
687}
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
690{
691 struct inode * inode;
692 int error;
693 struct iattr newattrs;
694
695 error = -ENOENT;
696 if (!(inode = dentry->d_inode)) {
697 printk(KERN_ERR "chown_common: NULL inode\n");
698 goto out;
699 }
700 error = -EROFS;
701 if (IS_RDONLY(inode))
702 goto out;
703 error = -EPERM;
704 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
705 goto out;
706 newattrs.ia_valid = ATTR_CTIME;
707 if (user != (uid_t) -1) {
708 newattrs.ia_valid |= ATTR_UID;
709 newattrs.ia_uid = user;
710 }
711 if (group != (gid_t) -1) {
712 newattrs.ia_valid |= ATTR_GID;
713 newattrs.ia_gid = group;
714 }
715 if (!S_ISDIR(inode->i_mode))
716 newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800717 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 error = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800719 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720out:
721 return error;
722}
723
724asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
725{
726 struct nameidata nd;
727 int error;
728
729 error = user_path_walk(filename, &nd);
730 if (!error) {
731 error = chown_common(nd.dentry, user, group);
732 path_release(&nd);
733 }
734 return error;
735}
736
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800737asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
738 gid_t group, int flag)
739{
740 struct nameidata nd;
741 int error = -EINVAL;
742 int follow;
743
744 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
745 goto out;
746
747 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
748 error = __user_walk_fd(dfd, filename, follow, &nd);
749 if (!error) {
750 error = chown_common(nd.dentry, user, group);
751 path_release(&nd);
752 }
753out:
754 return error;
755}
756
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
758{
759 struct nameidata nd;
760 int error;
761
762 error = user_path_walk_link(filename, &nd);
763 if (!error) {
764 error = chown_common(nd.dentry, user, group);
765 path_release(&nd);
766 }
767 return error;
768}
769
770
771asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
772{
773 struct file * file;
774 int error = -EBADF;
775
776 file = fget(fd);
777 if (file) {
778 error = chown_common(file->f_dentry, user, group);
779 fput(file);
780 }
781 return error;
782}
783
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700784static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
Trond Myklebust834f2a42005-10-18 14:20:16 -0700785 int flags, struct file *f,
786 int (*open)(struct inode *, struct file *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 struct inode *inode;
789 int error;
790
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 f->f_flags = flags;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700792 f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
793 FMODE_PREAD | FMODE_PWRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 inode = dentry->d_inode;
795 if (f->f_mode & FMODE_WRITE) {
796 error = get_write_access(inode);
797 if (error)
798 goto cleanup_file;
799 }
800
801 f->f_mapping = inode->i_mapping;
802 f->f_dentry = dentry;
803 f->f_vfsmnt = mnt;
804 f->f_pos = 0;
805 f->f_op = fops_get(inode->i_fop);
806 file_move(f, &inode->i_sb->s_files);
807
Trond Myklebust834f2a42005-10-18 14:20:16 -0700808 if (!open && f->f_op)
809 open = f->f_op->open;
810 if (open) {
811 error = open(inode, f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 if (error)
813 goto cleanup_all;
814 }
Trond Myklebust834f2a42005-10-18 14:20:16 -0700815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
817
818 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
819
820 /* NB: we're sure to have correct a_ops only after f_op->open */
821 if (f->f_flags & O_DIRECT) {
Carsten Otteceffc072005-06-23 22:05:25 -0700822 if (!f->f_mapping->a_ops ||
823 ((!f->f_mapping->a_ops->direct_IO) &&
824 (!f->f_mapping->a_ops->get_xip_page))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 fput(f);
826 f = ERR_PTR(-EINVAL);
827 }
828 }
829
830 return f;
831
832cleanup_all:
833 fops_put(f->f_op);
834 if (f->f_mode & FMODE_WRITE)
835 put_write_access(inode);
836 file_kill(f);
837 f->f_dentry = NULL;
838 f->f_vfsmnt = NULL;
839cleanup_file:
840 put_filp(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 dput(dentry);
842 mntput(mnt);
843 return ERR_PTR(error);
844}
845
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700846/*
847 * Note that while the flag value (low two bits) for sys_open means:
848 * 00 - read-only
849 * 01 - write-only
850 * 10 - read-write
851 * 11 - special
852 * it is changed into
853 * 00 - no permissions needed
854 * 01 - read-permission
855 * 10 - write-permission
856 * 11 - read-write
857 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
858 * used by symlinks.
859 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800860static struct file *do_filp_open(int dfd, const char *filename, int flags,
861 int mode)
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700862{
863 int namei_flags, error;
864 struct nameidata nd;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700865
866 namei_flags = flags;
867 if ((namei_flags+1) & O_ACCMODE)
868 namei_flags++;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700869
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800870 error = open_namei(dfd, filename, namei_flags, mode, &nd);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700871 if (!error)
Trond Myklebust834f2a42005-10-18 14:20:16 -0700872 return nameidata_to_filp(&nd, flags);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700873
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700874 return ERR_PTR(error);
875}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800876
877struct file *filp_open(const char *filename, int flags, int mode)
878{
879 return do_filp_open(AT_FDCWD, filename, flags, mode);
880}
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700881EXPORT_SYMBOL(filp_open);
882
Trond Myklebust834f2a42005-10-18 14:20:16 -0700883/**
884 * lookup_instantiate_filp - instantiates the open intent filp
885 * @nd: pointer to nameidata
886 * @dentry: pointer to dentry
887 * @open: open callback
888 *
889 * Helper for filesystems that want to use lookup open intents and pass back
890 * a fully instantiated struct file to the caller.
891 * This function is meant to be called from within a filesystem's
892 * lookup method.
893 * Note that in case of error, nd->intent.open.file is destroyed, but the
894 * path information remains valid.
895 * If the open callback is set to NULL, then the standard f_op->open()
896 * filesystem callback is substituted.
897 */
898struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
899 int (*open)(struct inode *, struct file *))
900{
901 if (IS_ERR(nd->intent.open.file))
902 goto out;
903 if (IS_ERR(dentry))
904 goto out_err;
905 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt),
906 nd->intent.open.flags - 1,
907 nd->intent.open.file,
908 open);
909out:
910 return nd->intent.open.file;
911out_err:
912 release_open_intent(nd);
913 nd->intent.open.file = (struct file *)dentry;
914 goto out;
915}
916EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
917
918/**
919 * nameidata_to_filp - convert a nameidata to an open filp.
920 * @nd: pointer to nameidata
921 * @flags: open flags
922 *
923 * Note that this function destroys the original nameidata
924 */
925struct file *nameidata_to_filp(struct nameidata *nd, int flags)
926{
927 struct file *filp;
928
929 /* Pick up the filp from the open intent */
930 filp = nd->intent.open.file;
931 /* Has the filesystem initialised the file for us? */
932 if (filp->f_dentry == NULL)
933 filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL);
934 else
935 path_release(nd);
936 return filp;
937}
938
Peter Staubach6fdcc212005-11-07 00:59:42 -0800939/*
940 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
941 * error.
942 */
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700943struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
944{
945 int error;
946 struct file *f;
947
948 error = -ENFILE;
949 f = get_empty_filp();
Peter Staubach6fdcc212005-11-07 00:59:42 -0800950 if (f == NULL) {
951 dput(dentry);
952 mntput(mnt);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700953 return ERR_PTR(error);
Peter Staubach6fdcc212005-11-07 00:59:42 -0800954 }
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700955
Trond Myklebust834f2a42005-10-18 14:20:16 -0700956 return __dentry_open(dentry, mnt, flags, f, NULL);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700957}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958EXPORT_SYMBOL(dentry_open);
959
960/*
961 * Find an empty file descriptor entry, and mark it busy.
962 */
963int get_unused_fd(void)
964{
965 struct files_struct * files = current->files;
966 int fd, error;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700967 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
969 error = -EMFILE;
970 spin_lock(&files->file_lock);
971
972repeat:
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700973 fdt = files_fdtable(files);
974 fd = find_next_zero_bit(fdt->open_fds->fds_bits,
975 fdt->max_fdset,
976 fdt->next_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
978 /*
979 * N.B. For clone tasks sharing a files structure, this test
980 * will limit the total number of files that can be opened.
981 */
982 if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
983 goto out;
984
985 /* Do we need to expand the fd array or fd set? */
986 error = expand_files(files, fd);
987 if (error < 0)
988 goto out;
989
990 if (error) {
991 /*
992 * If we needed to expand the fs array we
993 * might have blocked - try again.
994 */
995 error = -EMFILE;
996 goto repeat;
997 }
998
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700999 FD_SET(fd, fdt->open_fds);
1000 FD_CLR(fd, fdt->close_on_exec);
1001 fdt->next_fd = fd + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002#if 1
1003 /* Sanity check */
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001004 if (fdt->fd[fd] != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001006 fdt->fd[fd] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 }
1008#endif
1009 error = fd;
1010
1011out:
1012 spin_unlock(&files->file_lock);
1013 return error;
1014}
1015
1016EXPORT_SYMBOL(get_unused_fd);
1017
Matt Mackallb01ec0e2006-01-08 01:05:20 -08001018static void __put_unused_fd(struct files_struct *files, unsigned int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019{
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001020 struct fdtable *fdt = files_fdtable(files);
1021 __FD_CLR(fd, fdt->open_fds);
1022 if (fd < fdt->next_fd)
1023 fdt->next_fd = fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024}
1025
1026void fastcall put_unused_fd(unsigned int fd)
1027{
1028 struct files_struct *files = current->files;
1029 spin_lock(&files->file_lock);
1030 __put_unused_fd(files, fd);
1031 spin_unlock(&files->file_lock);
1032}
1033
1034EXPORT_SYMBOL(put_unused_fd);
1035
1036/*
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001037 * Install a file pointer in the fd array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 *
1039 * The VFS is full of places where we drop the files lock between
1040 * setting the open_fds bitmap and installing the file in the file
1041 * array. At any such point, we are vulnerable to a dup2() race
1042 * installing a file in the array before us. We need to detect this and
1043 * fput() the struct file we are about to overwrite in this case.
1044 *
1045 * It should never happen - if we allow dup2() do it, _really_ bad things
1046 * will follow.
1047 */
1048
1049void fastcall fd_install(unsigned int fd, struct file * file)
1050{
1051 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001052 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001054 fdt = files_fdtable(files);
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -07001055 BUG_ON(fdt->fd[fd] != NULL);
1056 rcu_assign_pointer(fdt->fd[fd], file);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 spin_unlock(&files->file_lock);
1058}
1059
1060EXPORT_SYMBOL(fd_install);
1061
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001062long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063{
Miklos Szeredie922efc2005-09-06 15:18:25 -07001064 char *tmp = getname(filename);
1065 int fd = PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 if (!IS_ERR(tmp)) {
1068 fd = get_unused_fd();
1069 if (fd >= 0) {
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001070 struct file *f = do_filp_open(dfd, tmp, flags, mode);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -07001071 if (IS_ERR(f)) {
1072 put_unused_fd(fd);
1073 fd = PTR_ERR(f);
1074 } else {
Robert Love0eeca282005-07-12 17:06:03 -04001075 fsnotify_open(f->f_dentry);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -07001076 fd_install(fd, f);
1077 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 putname(tmp);
1080 }
1081 return fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082}
Miklos Szeredie922efc2005-09-06 15:18:25 -07001083
1084asmlinkage long sys_open(const char __user *filename, int flags, int mode)
1085{
1086 if (force_o_largefile())
1087 flags |= O_LARGEFILE;
1088
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001089 return do_sys_open(AT_FDCWD, filename, flags, mode);
Miklos Szeredie922efc2005-09-06 15:18:25 -07001090}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091EXPORT_SYMBOL_GPL(sys_open);
1092
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001093asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
1094 int mode)
1095{
1096 if (force_o_largefile())
1097 flags |= O_LARGEFILE;
1098
1099 return do_sys_open(dfd, filename, flags, mode);
1100}
1101EXPORT_SYMBOL_GPL(sys_openat);
1102
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103#ifndef __alpha__
1104
1105/*
1106 * For backward compatibility? Maybe this should be moved
1107 * into arch/i386 instead?
1108 */
1109asmlinkage long sys_creat(const char __user * pathname, int mode)
1110{
1111 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1112}
1113
1114#endif
1115
1116/*
1117 * "id" is the POSIX thread ID. We use the
1118 * files pointer for this..
1119 */
1120int filp_close(struct file *filp, fl_owner_t id)
1121{
Christoph Lameter45778ca2005-06-23 00:10:17 -07001122 int retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123
1124 if (!file_count(filp)) {
1125 printk(KERN_ERR "VFS: Close: file count is 0\n");
Christoph Lameter45778ca2005-06-23 00:10:17 -07001126 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 }
1128
Christoph Lameter45778ca2005-06-23 00:10:17 -07001129 if (filp->f_op && filp->f_op->flush)
1130 retval = filp->f_op->flush(filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131
1132 dnotify_flush(filp, id);
1133 locks_remove_posix(filp, id);
1134 fput(filp);
1135 return retval;
1136}
1137
1138EXPORT_SYMBOL(filp_close);
1139
1140/*
1141 * Careful here! We test whether the file pointer is NULL before
1142 * releasing the fd. This ensures that one clone task can't release
1143 * an fd while another clone is opening it.
1144 */
1145asmlinkage long sys_close(unsigned int fd)
1146{
1147 struct file * filp;
1148 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001149 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150
1151 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001152 fdt = files_fdtable(files);
1153 if (fd >= fdt->max_fds)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 goto out_unlock;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001155 filp = fdt->fd[fd];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 if (!filp)
1157 goto out_unlock;
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -07001158 rcu_assign_pointer(fdt->fd[fd], NULL);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001159 FD_CLR(fd, fdt->close_on_exec);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 __put_unused_fd(files, fd);
1161 spin_unlock(&files->file_lock);
1162 return filp_close(filp, files);
1163
1164out_unlock:
1165 spin_unlock(&files->file_lock);
1166 return -EBADF;
1167}
1168
1169EXPORT_SYMBOL(sys_close);
1170
1171/*
1172 * This routine simulates a hangup on the tty, to arrange that users
1173 * are given clean terminals at login time.
1174 */
1175asmlinkage long sys_vhangup(void)
1176{
1177 if (capable(CAP_SYS_TTY_CONFIG)) {
1178 tty_vhangup(current->signal->tty);
1179 return 0;
1180 }
1181 return -EPERM;
1182}
1183
1184/*
1185 * Called when an inode is about to be open.
1186 * We use this to disallow opening large files on 32bit systems if
1187 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1188 * on this flag in sys_open.
1189 */
1190int generic_file_open(struct inode * inode, struct file * filp)
1191{
1192 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1193 return -EFBIG;
1194 return 0;
1195}
1196
1197EXPORT_SYMBOL(generic_file_open);
1198
1199/*
1200 * This is used by subsystems that don't want seekable
1201 * file descriptors
1202 */
1203int nonseekable_open(struct inode *inode, struct file *filp)
1204{
1205 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1206 return 0;
1207}
1208
1209EXPORT_SYMBOL(nonseekable_open);