blob: c989fb4cf7b9ce1bfc479ca7a0b6a4881e333c63 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/file.h>
10#include <linux/smp_lock.h>
11#include <linux/quotaops.h>
Robert Love0eeca282005-07-12 17:06:03 -040012#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#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>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080018#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/security.h>
20#include <linux/mount.h>
21#include <linux/vfs.h>
Ulrich Drepper5590ff02006-01-18 17:43:53 -080022#include <linux/fcntl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <asm/uaccess.h>
24#include <linux/fs.h>
Yoav Zachef3daed2005-06-23 00:09:58 -070025#include <linux/personality.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/pagemap.h>
27#include <linux/syscalls.h>
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -070028#include <linux/rcupdate.h>
Amy Griffis73241cc2005-11-03 16:00:25 +000029#include <linux/audit.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
David Howells726c3342006-06-23 02:02:58 -070031int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
33 int retval = -ENODEV;
34
David Howells726c3342006-06-23 02:02:58 -070035 if (dentry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 retval = -ENOSYS;
David Howells726c3342006-06-23 02:02:58 -070037 if (dentry->d_sb->s_op->statfs) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 memset(buf, 0, sizeof(*buf));
David Howells726c3342006-06-23 02:02:58 -070039 retval = security_sb_statfs(dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 if (retval)
41 return retval;
David Howells726c3342006-06-23 02:02:58 -070042 retval = dentry->d_sb->s_op->statfs(dentry, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 if (retval == 0 && buf->f_frsize == 0)
44 buf->f_frsize = buf->f_bsize;
45 }
46 }
47 return retval;
48}
49
50EXPORT_SYMBOL(vfs_statfs);
51
David Howells726c3342006-06-23 02:02:58 -070052static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
54 struct kstatfs st;
55 int retval;
56
David Howells726c3342006-06-23 02:02:58 -070057 retval = vfs_statfs(dentry, &st);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 if (retval)
59 return retval;
60
61 if (sizeof(*buf) == sizeof(st))
62 memcpy(buf, &st, sizeof(st));
63 else {
64 if (sizeof buf->f_blocks == 4) {
65 if ((st.f_blocks | st.f_bfree | st.f_bavail) &
66 0xffffffff00000000ULL)
67 return -EOVERFLOW;
68 /*
69 * f_files and f_ffree may be -1; it's okay to stuff
70 * that into 32 bits
71 */
72 if (st.f_files != -1 &&
73 (st.f_files & 0xffffffff00000000ULL))
74 return -EOVERFLOW;
75 if (st.f_ffree != -1 &&
76 (st.f_ffree & 0xffffffff00000000ULL))
77 return -EOVERFLOW;
78 }
79
80 buf->f_type = st.f_type;
81 buf->f_bsize = st.f_bsize;
82 buf->f_blocks = st.f_blocks;
83 buf->f_bfree = st.f_bfree;
84 buf->f_bavail = st.f_bavail;
85 buf->f_files = st.f_files;
86 buf->f_ffree = st.f_ffree;
87 buf->f_fsid = st.f_fsid;
88 buf->f_namelen = st.f_namelen;
89 buf->f_frsize = st.f_frsize;
90 memset(buf->f_spare, 0, sizeof(buf->f_spare));
91 }
92 return 0;
93}
94
David Howells726c3342006-06-23 02:02:58 -070095static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
97 struct kstatfs st;
98 int retval;
99
David Howells726c3342006-06-23 02:02:58 -0700100 retval = vfs_statfs(dentry, &st);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 if (retval)
102 return retval;
103
104 if (sizeof(*buf) == sizeof(st))
105 memcpy(buf, &st, sizeof(st));
106 else {
107 buf->f_type = st.f_type;
108 buf->f_bsize = st.f_bsize;
109 buf->f_blocks = st.f_blocks;
110 buf->f_bfree = st.f_bfree;
111 buf->f_bavail = st.f_bavail;
112 buf->f_files = st.f_files;
113 buf->f_ffree = st.f_ffree;
114 buf->f_fsid = st.f_fsid;
115 buf->f_namelen = st.f_namelen;
116 buf->f_frsize = st.f_frsize;
117 memset(buf->f_spare, 0, sizeof(buf->f_spare));
118 }
119 return 0;
120}
121
122asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf)
123{
124 struct nameidata nd;
125 int error;
126
127 error = user_path_walk(path, &nd);
128 if (!error) {
129 struct statfs tmp;
David Howells726c3342006-06-23 02:02:58 -0700130 error = vfs_statfs_native(nd.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
132 error = -EFAULT;
133 path_release(&nd);
134 }
135 return error;
136}
137
138
139asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf)
140{
141 struct nameidata nd;
142 long error;
143
144 if (sz != sizeof(*buf))
145 return -EINVAL;
146 error = user_path_walk(path, &nd);
147 if (!error) {
148 struct statfs64 tmp;
David Howells726c3342006-06-23 02:02:58 -0700149 error = vfs_statfs64(nd.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
151 error = -EFAULT;
152 path_release(&nd);
153 }
154 return error;
155}
156
157
158asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf)
159{
160 struct file * file;
161 struct statfs tmp;
162 int error;
163
164 error = -EBADF;
165 file = fget(fd);
166 if (!file)
167 goto out;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800168 error = vfs_statfs_native(file->f_path.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
170 error = -EFAULT;
171 fput(file);
172out:
173 return error;
174}
175
176asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf)
177{
178 struct file * file;
179 struct statfs64 tmp;
180 int error;
181
182 if (sz != sizeof(*buf))
183 return -EINVAL;
184
185 error = -EBADF;
186 file = fget(fd);
187 if (!file)
188 goto out;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800189 error = vfs_statfs64(file->f_path.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
191 error = -EFAULT;
192 fput(file);
193out:
194 return error;
195}
196
NeilBrown4a301312006-01-08 01:02:39 -0800197int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
198 struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
200 int err;
201 struct iattr newattrs;
202
203 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
204 if (length < 0)
205 return -EINVAL;
206
207 newattrs.ia_size = length;
NeilBrown4a301312006-01-08 01:02:39 -0800208 newattrs.ia_valid = ATTR_SIZE | time_attrs;
Miklos Szeredicc4e69d2005-11-07 00:59:49 -0800209 if (filp) {
210 newattrs.ia_file = filp;
211 newattrs.ia_valid |= ATTR_FILE;
212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800214 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800216 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 return err;
218}
219
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800220static long do_sys_truncate(const char __user * path, loff_t length)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
222 struct nameidata nd;
223 struct inode * inode;
224 int error;
225
226 error = -EINVAL;
227 if (length < 0) /* sorry, but loff_t says... */
228 goto out;
229
230 error = user_path_walk(path, &nd);
231 if (error)
232 goto out;
233 inode = nd.dentry->d_inode;
234
235 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
236 error = -EISDIR;
237 if (S_ISDIR(inode->i_mode))
238 goto dput_and_out;
239
240 error = -EINVAL;
241 if (!S_ISREG(inode->i_mode))
242 goto dput_and_out;
243
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800244 error = vfs_permission(&nd, MAY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (error)
246 goto dput_and_out;
247
248 error = -EROFS;
249 if (IS_RDONLY(inode))
250 goto dput_and_out;
251
252 error = -EPERM;
253 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
254 goto dput_and_out;
255
256 /*
257 * Make sure that there are no leases.
258 */
259 error = break_lease(inode, FMODE_WRITE);
260 if (error)
261 goto dput_and_out;
262
263 error = get_write_access(inode);
264 if (error)
265 goto dput_and_out;
266
267 error = locks_verify_truncate(inode, NULL, length);
268 if (!error) {
269 DQUOT_INIT(inode);
NeilBrown4a301312006-01-08 01:02:39 -0800270 error = do_truncate(nd.dentry, length, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 }
272 put_write_access(inode);
273
274dput_and_out:
275 path_release(&nd);
276out:
277 return error;
278}
279
280asmlinkage long sys_truncate(const char __user * path, unsigned long length)
281{
282 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
283 return do_sys_truncate(path, (long)length);
284}
285
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800286static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
288 struct inode * inode;
289 struct dentry *dentry;
290 struct file * file;
291 int error;
292
293 error = -EINVAL;
294 if (length < 0)
295 goto out;
296 error = -EBADF;
297 file = fget(fd);
298 if (!file)
299 goto out;
300
301 /* explicitly opened as large or we are on 64-bit box */
302 if (file->f_flags & O_LARGEFILE)
303 small = 0;
304
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800305 dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 inode = dentry->d_inode;
307 error = -EINVAL;
308 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
309 goto out_putf;
310
311 error = -EINVAL;
312 /* Cannot ftruncate over 2^31 bytes without large file support */
313 if (small && length > MAX_NON_LFS)
314 goto out_putf;
315
316 error = -EPERM;
317 if (IS_APPEND(inode))
318 goto out_putf;
319
320 error = locks_verify_truncate(inode, file, length);
321 if (!error)
Peter Staubach6e656be2006-06-25 05:48:36 -0700322 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323out_putf:
324 fput(file);
325out:
326 return error;
327}
328
329asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
330{
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700331 long ret = do_sys_ftruncate(fd, length, 1);
Linus Torvalds385910f2006-04-18 13:22:59 -0700332 /* avoid REGPARM breakage on x86: */
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700333 prevent_tail_call(ret);
334 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335}
336
337/* LFS versions of truncate are only needed on 32 bit machines */
338#if BITS_PER_LONG == 32
339asmlinkage long sys_truncate64(const char __user * path, loff_t length)
340{
341 return do_sys_truncate(path, length);
342}
343
344asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
345{
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700346 long ret = do_sys_ftruncate(fd, length, 0);
Linus Torvalds385910f2006-04-18 13:22:59 -0700347 /* avoid REGPARM breakage on x86: */
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700348 prevent_tail_call(ret);
349 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351#endif
352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353/*
354 * access() needs to use the real uid/gid, not the effective uid/gid.
355 * We do this by temporarily clearing all FS-related capabilities and
356 * switching the fsuid/fsgid around to the real ones.
357 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800358asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
360 struct nameidata nd;
361 int old_fsuid, old_fsgid;
362 kernel_cap_t old_cap;
363 int res;
364
365 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
366 return -EINVAL;
367
368 old_fsuid = current->fsuid;
369 old_fsgid = current->fsgid;
370 old_cap = current->cap_effective;
371
372 current->fsuid = current->uid;
373 current->fsgid = current->gid;
374
375 /*
376 * Clear the capabilities if we switch to a non-root user
377 *
378 * FIXME: There is a race here against sys_capset. The
379 * capabilities can change yet we will restore the old
380 * value below. We should hold task_capabilities_lock,
381 * but we cannot because user_path_walk can sleep.
382 */
383 if (current->uid)
384 cap_clear(current->cap_effective);
385 else
386 current->cap_effective = current->cap_permitted;
387
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800388 res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700389 if (res)
390 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Dave Hansen6902d922006-09-30 23:29:01 -0700392 res = vfs_permission(&nd, mode);
393 /* SuS v2 requires we report a read only fs too */
394 if(res || !(mode & S_IWOTH) ||
395 special_file(nd.dentry->d_inode->i_mode))
396 goto out_path_release;
397
398 if(IS_RDONLY(nd.dentry->d_inode))
399 res = -EROFS;
400
401out_path_release:
402 path_release(&nd);
403out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 current->fsuid = old_fsuid;
405 current->fsgid = old_fsgid;
406 current->cap_effective = old_cap;
407
408 return res;
409}
410
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800411asmlinkage long sys_access(const char __user *filename, int mode)
412{
413 return sys_faccessat(AT_FDCWD, filename, mode);
414}
415
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416asmlinkage long sys_chdir(const char __user * filename)
417{
418 struct nameidata nd;
419 int error;
420
Miklos Szeredi650a8982006-09-29 01:59:35 -0700421 error = __user_walk(filename,
422 LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 if (error)
424 goto out;
425
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800426 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 if (error)
428 goto dput_and_out;
429
430 set_fs_pwd(current->fs, nd.mnt, nd.dentry);
431
432dput_and_out:
433 path_release(&nd);
434out:
435 return error;
436}
437
438asmlinkage long sys_fchdir(unsigned int fd)
439{
440 struct file *file;
441 struct dentry *dentry;
442 struct inode *inode;
443 struct vfsmount *mnt;
444 int error;
445
446 error = -EBADF;
447 file = fget(fd);
448 if (!file)
449 goto out;
450
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800451 dentry = file->f_path.dentry;
452 mnt = file->f_path.mnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 inode = dentry->d_inode;
454
455 error = -ENOTDIR;
456 if (!S_ISDIR(inode->i_mode))
457 goto out_putf;
458
Christoph Hellwig8c744fb2005-11-08 21:35:04 -0800459 error = file_permission(file, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 if (!error)
461 set_fs_pwd(current->fs, mnt, dentry);
462out_putf:
463 fput(file);
464out:
465 return error;
466}
467
468asmlinkage long sys_chroot(const char __user * filename)
469{
470 struct nameidata nd;
471 int error;
472
473 error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
474 if (error)
475 goto out;
476
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800477 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 if (error)
479 goto dput_and_out;
480
481 error = -EPERM;
482 if (!capable(CAP_SYS_CHROOT))
483 goto dput_and_out;
484
485 set_fs_root(current->fs, nd.mnt, nd.dentry);
486 set_fs_altroot();
487 error = 0;
488dput_and_out:
489 path_release(&nd);
490out:
491 return error;
492}
493
494asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
495{
496 struct inode * inode;
497 struct dentry * dentry;
498 struct file * file;
499 int err = -EBADF;
500 struct iattr newattrs;
501
502 file = fget(fd);
503 if (!file)
504 goto out;
505
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800506 dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 inode = dentry->d_inode;
508
Amy Griffis9c937dc2006-06-08 23:19:31 -0400509 audit_inode(NULL, inode);
Amy Griffis73241cc2005-11-03 16:00:25 +0000510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 err = -EROFS;
512 if (IS_RDONLY(inode))
513 goto out_putf;
514 err = -EPERM;
515 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
516 goto out_putf;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800517 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 if (mode == (mode_t) -1)
519 mode = inode->i_mode;
520 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
521 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
522 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800523 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
525out_putf:
526 fput(file);
527out:
528 return err;
529}
530
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800531asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
532 mode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533{
534 struct nameidata nd;
535 struct inode * inode;
536 int error;
537 struct iattr newattrs;
538
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800539 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 if (error)
541 goto out;
542 inode = nd.dentry->d_inode;
543
544 error = -EROFS;
545 if (IS_RDONLY(inode))
546 goto dput_and_out;
547
548 error = -EPERM;
549 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
550 goto dput_and_out;
551
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800552 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 if (mode == (mode_t) -1)
554 mode = inode->i_mode;
555 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
556 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
557 error = notify_change(nd.dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800558 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560dput_and_out:
561 path_release(&nd);
562out:
563 return error;
564}
565
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800566asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
567{
568 return sys_fchmodat(AT_FDCWD, filename, mode);
569}
570
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
572{
573 struct inode * inode;
574 int error;
575 struct iattr newattrs;
576
577 error = -ENOENT;
578 if (!(inode = dentry->d_inode)) {
579 printk(KERN_ERR "chown_common: NULL inode\n");
580 goto out;
581 }
582 error = -EROFS;
583 if (IS_RDONLY(inode))
584 goto out;
585 error = -EPERM;
586 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
587 goto out;
588 newattrs.ia_valid = ATTR_CTIME;
589 if (user != (uid_t) -1) {
590 newattrs.ia_valid |= ATTR_UID;
591 newattrs.ia_uid = user;
592 }
593 if (group != (gid_t) -1) {
594 newattrs.ia_valid |= ATTR_GID;
595 newattrs.ia_gid = group;
596 }
597 if (!S_ISDIR(inode->i_mode))
598 newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800599 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 error = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800601 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602out:
603 return error;
604}
605
606asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
607{
608 struct nameidata nd;
609 int error;
610
611 error = user_path_walk(filename, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700612 if (error)
613 goto out;
614 error = chown_common(nd.dentry, user, group);
615 path_release(&nd);
616out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 return error;
618}
619
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800620asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
621 gid_t group, int flag)
622{
623 struct nameidata nd;
624 int error = -EINVAL;
625 int follow;
626
627 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
628 goto out;
629
630 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
631 error = __user_walk_fd(dfd, filename, follow, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700632 if (error)
633 goto out;
634 error = chown_common(nd.dentry, user, group);
635 path_release(&nd);
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800636out:
637 return error;
638}
639
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
641{
642 struct nameidata nd;
643 int error;
644
645 error = user_path_walk_link(filename, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700646 if (error)
647 goto out;
648 error = chown_common(nd.dentry, user, group);
649 path_release(&nd);
650out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 return error;
652}
653
654
655asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
656{
657 struct file * file;
658 int error = -EBADF;
Dave Hansen6902d922006-09-30 23:29:01 -0700659 struct dentry * dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660
661 file = fget(fd);
Dave Hansen6902d922006-09-30 23:29:01 -0700662 if (!file)
663 goto out;
664
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800665 dentry = file->f_path.dentry;
Dave Hansen6902d922006-09-30 23:29:01 -0700666 audit_inode(NULL, dentry->d_inode);
667 error = chown_common(dentry, user, group);
668 fput(file);
669out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 return error;
671}
672
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700673static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
Trond Myklebust834f2a42005-10-18 14:20:16 -0700674 int flags, struct file *f,
675 int (*open)(struct inode *, struct file *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 struct inode *inode;
678 int error;
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 f->f_flags = flags;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700681 f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
682 FMODE_PREAD | FMODE_PWRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 inode = dentry->d_inode;
684 if (f->f_mode & FMODE_WRITE) {
685 error = get_write_access(inode);
686 if (error)
687 goto cleanup_file;
688 }
689
690 f->f_mapping = inode->i_mapping;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800691 f->f_path.dentry = dentry;
692 f->f_path.mnt = mnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 f->f_pos = 0;
694 f->f_op = fops_get(inode->i_fop);
695 file_move(f, &inode->i_sb->s_files);
696
Trond Myklebust834f2a42005-10-18 14:20:16 -0700697 if (!open && f->f_op)
698 open = f->f_op->open;
699 if (open) {
700 error = open(inode, f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (error)
702 goto cleanup_all;
703 }
Trond Myklebust834f2a42005-10-18 14:20:16 -0700704
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
706
707 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
708
709 /* NB: we're sure to have correct a_ops only after f_op->open */
710 if (f->f_flags & O_DIRECT) {
Carsten Otteceffc072005-06-23 22:05:25 -0700711 if (!f->f_mapping->a_ops ||
712 ((!f->f_mapping->a_ops->direct_IO) &&
713 (!f->f_mapping->a_ops->get_xip_page))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 fput(f);
715 f = ERR_PTR(-EINVAL);
716 }
717 }
718
719 return f;
720
721cleanup_all:
722 fops_put(f->f_op);
723 if (f->f_mode & FMODE_WRITE)
724 put_write_access(inode);
725 file_kill(f);
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800726 f->f_path.dentry = NULL;
727 f->f_path.mnt = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728cleanup_file:
729 put_filp(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 dput(dentry);
731 mntput(mnt);
732 return ERR_PTR(error);
733}
734
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700735/*
736 * Note that while the flag value (low two bits) for sys_open means:
737 * 00 - read-only
738 * 01 - write-only
739 * 10 - read-write
740 * 11 - special
741 * it is changed into
742 * 00 - no permissions needed
743 * 01 - read-permission
744 * 10 - write-permission
745 * 11 - read-write
746 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
747 * used by symlinks.
748 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800749static struct file *do_filp_open(int dfd, const char *filename, int flags,
750 int mode)
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700751{
752 int namei_flags, error;
753 struct nameidata nd;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700754
755 namei_flags = flags;
756 if ((namei_flags+1) & O_ACCMODE)
757 namei_flags++;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700758
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800759 error = open_namei(dfd, filename, namei_flags, mode, &nd);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700760 if (!error)
Trond Myklebust834f2a42005-10-18 14:20:16 -0700761 return nameidata_to_filp(&nd, flags);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700762
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700763 return ERR_PTR(error);
764}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800765
766struct file *filp_open(const char *filename, int flags, int mode)
767{
768 return do_filp_open(AT_FDCWD, filename, flags, mode);
769}
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700770EXPORT_SYMBOL(filp_open);
771
Trond Myklebust834f2a42005-10-18 14:20:16 -0700772/**
773 * lookup_instantiate_filp - instantiates the open intent filp
774 * @nd: pointer to nameidata
775 * @dentry: pointer to dentry
776 * @open: open callback
777 *
778 * Helper for filesystems that want to use lookup open intents and pass back
779 * a fully instantiated struct file to the caller.
780 * This function is meant to be called from within a filesystem's
781 * lookup method.
Oleg Drokin9a56c212006-03-25 03:07:02 -0800782 * Beware of calling it for non-regular files! Those ->open methods might block
783 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
784 * leading to a deadlock, as nobody can open that fifo anymore, because
785 * another process to open fifo will block on locked parent when doing lookup).
Trond Myklebust834f2a42005-10-18 14:20:16 -0700786 * Note that in case of error, nd->intent.open.file is destroyed, but the
787 * path information remains valid.
788 * If the open callback is set to NULL, then the standard f_op->open()
789 * filesystem callback is substituted.
790 */
791struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
792 int (*open)(struct inode *, struct file *))
793{
794 if (IS_ERR(nd->intent.open.file))
795 goto out;
796 if (IS_ERR(dentry))
797 goto out_err;
798 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt),
799 nd->intent.open.flags - 1,
800 nd->intent.open.file,
801 open);
802out:
803 return nd->intent.open.file;
804out_err:
805 release_open_intent(nd);
806 nd->intent.open.file = (struct file *)dentry;
807 goto out;
808}
809EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
810
811/**
812 * nameidata_to_filp - convert a nameidata to an open filp.
813 * @nd: pointer to nameidata
814 * @flags: open flags
815 *
816 * Note that this function destroys the original nameidata
817 */
818struct file *nameidata_to_filp(struct nameidata *nd, int flags)
819{
820 struct file *filp;
821
822 /* Pick up the filp from the open intent */
823 filp = nd->intent.open.file;
824 /* Has the filesystem initialised the file for us? */
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800825 if (filp->f_path.dentry == NULL)
Trond Myklebust834f2a42005-10-18 14:20:16 -0700826 filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL);
827 else
828 path_release(nd);
829 return filp;
830}
831
Peter Staubach6fdcc212005-11-07 00:59:42 -0800832/*
833 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
834 * error.
835 */
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700836struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
837{
838 int error;
839 struct file *f;
840
841 error = -ENFILE;
842 f = get_empty_filp();
Peter Staubach6fdcc212005-11-07 00:59:42 -0800843 if (f == NULL) {
844 dput(dentry);
845 mntput(mnt);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700846 return ERR_PTR(error);
Peter Staubach6fdcc212005-11-07 00:59:42 -0800847 }
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700848
Trond Myklebust834f2a42005-10-18 14:20:16 -0700849 return __dentry_open(dentry, mnt, flags, f, NULL);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700850}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851EXPORT_SYMBOL(dentry_open);
852
853/*
854 * Find an empty file descriptor entry, and mark it busy.
855 */
856int get_unused_fd(void)
857{
858 struct files_struct * files = current->files;
859 int fd, error;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700860 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862 error = -EMFILE;
863 spin_lock(&files->file_lock);
864
865repeat:
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700866 fdt = files_fdtable(files);
Vadim Lobanovbbea9f62006-12-10 02:21:12 -0800867 fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800868 files->next_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
870 /*
871 * N.B. For clone tasks sharing a files structure, this test
872 * will limit the total number of files that can be opened.
873 */
874 if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
875 goto out;
876
877 /* Do we need to expand the fd array or fd set? */
878 error = expand_files(files, fd);
879 if (error < 0)
880 goto out;
881
882 if (error) {
883 /*
884 * If we needed to expand the fs array we
885 * might have blocked - try again.
886 */
887 error = -EMFILE;
888 goto repeat;
889 }
890
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700891 FD_SET(fd, fdt->open_fds);
892 FD_CLR(fd, fdt->close_on_exec);
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800893 files->next_fd = fd + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894#if 1
895 /* Sanity check */
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700896 if (fdt->fd[fd] != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700898 fdt->fd[fd] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 }
900#endif
901 error = fd;
902
903out:
904 spin_unlock(&files->file_lock);
905 return error;
906}
907
908EXPORT_SYMBOL(get_unused_fd);
909
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800910static void __put_unused_fd(struct files_struct *files, unsigned int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911{
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700912 struct fdtable *fdt = files_fdtable(files);
913 __FD_CLR(fd, fdt->open_fds);
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800914 if (fd < files->next_fd)
915 files->next_fd = fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916}
917
918void fastcall put_unused_fd(unsigned int fd)
919{
920 struct files_struct *files = current->files;
921 spin_lock(&files->file_lock);
922 __put_unused_fd(files, fd);
923 spin_unlock(&files->file_lock);
924}
925
926EXPORT_SYMBOL(put_unused_fd);
927
928/*
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800929 * Install a file pointer in the fd array.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 *
931 * The VFS is full of places where we drop the files lock between
932 * setting the open_fds bitmap and installing the file in the file
933 * array. At any such point, we are vulnerable to a dup2() race
934 * installing a file in the array before us. We need to detect this and
935 * fput() the struct file we are about to overwrite in this case.
936 *
937 * It should never happen - if we allow dup2() do it, _really_ bad things
938 * will follow.
939 */
940
941void fastcall fd_install(unsigned int fd, struct file * file)
942{
943 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700944 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700946 fdt = files_fdtable(files);
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -0700947 BUG_ON(fdt->fd[fd] != NULL);
948 rcu_assign_pointer(fdt->fd[fd], file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 spin_unlock(&files->file_lock);
950}
951
952EXPORT_SYMBOL(fd_install);
953
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800954long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955{
Miklos Szeredie922efc2005-09-06 15:18:25 -0700956 char *tmp = getname(filename);
957 int fd = PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 if (!IS_ERR(tmp)) {
960 fd = get_unused_fd();
961 if (fd >= 0) {
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800962 struct file *f = do_filp_open(dfd, tmp, flags, mode);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -0700963 if (IS_ERR(f)) {
964 put_unused_fd(fd);
965 fd = PTR_ERR(f);
966 } else {
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800967 fsnotify_open(f->f_path.dentry);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -0700968 fd_install(fd, f);
969 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 putname(tmp);
972 }
973 return fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974}
Miklos Szeredie922efc2005-09-06 15:18:25 -0700975
976asmlinkage long sys_open(const char __user *filename, int flags, int mode)
977{
Linus Torvalds385910f2006-04-18 13:22:59 -0700978 long ret;
979
Miklos Szeredie922efc2005-09-06 15:18:25 -0700980 if (force_o_largefile())
981 flags |= O_LARGEFILE;
982
Linus Torvalds385910f2006-04-18 13:22:59 -0700983 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
984 /* avoid REGPARM breakage on x86: */
985 prevent_tail_call(ret);
986 return ret;
Miklos Szeredie922efc2005-09-06 15:18:25 -0700987}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988EXPORT_SYMBOL_GPL(sys_open);
989
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800990asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
991 int mode)
992{
Linus Torvalds385910f2006-04-18 13:22:59 -0700993 long ret;
994
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800995 if (force_o_largefile())
996 flags |= O_LARGEFILE;
997
Linus Torvalds385910f2006-04-18 13:22:59 -0700998 ret = do_sys_open(dfd, filename, flags, mode);
999 /* avoid REGPARM breakage on x86: */
1000 prevent_tail_call(ret);
1001 return ret;
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001002}
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001003
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004#ifndef __alpha__
1005
1006/*
1007 * For backward compatibility? Maybe this should be moved
1008 * into arch/i386 instead?
1009 */
1010asmlinkage long sys_creat(const char __user * pathname, int mode)
1011{
1012 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1013}
1014
1015#endif
1016
1017/*
1018 * "id" is the POSIX thread ID. We use the
1019 * files pointer for this..
1020 */
1021int filp_close(struct file *filp, fl_owner_t id)
1022{
Christoph Lameter45778ca2005-06-23 00:10:17 -07001023 int retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024
1025 if (!file_count(filp)) {
1026 printk(KERN_ERR "VFS: Close: file count is 0\n");
Christoph Lameter45778ca2005-06-23 00:10:17 -07001027 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 }
1029
Christoph Lameter45778ca2005-06-23 00:10:17 -07001030 if (filp->f_op && filp->f_op->flush)
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -07001031 retval = filp->f_op->flush(filp, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032
1033 dnotify_flush(filp, id);
1034 locks_remove_posix(filp, id);
1035 fput(filp);
1036 return retval;
1037}
1038
1039EXPORT_SYMBOL(filp_close);
1040
1041/*
1042 * Careful here! We test whether the file pointer is NULL before
1043 * releasing the fd. This ensures that one clone task can't release
1044 * an fd while another clone is opening it.
1045 */
1046asmlinkage long sys_close(unsigned int fd)
1047{
1048 struct file * filp;
1049 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001050 struct fdtable *fdt;
Ernie Petridesee731f42006-09-29 02:00:13 -07001051 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052
1053 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001054 fdt = files_fdtable(files);
1055 if (fd >= fdt->max_fds)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 goto out_unlock;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001057 filp = fdt->fd[fd];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 if (!filp)
1059 goto out_unlock;
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -07001060 rcu_assign_pointer(fdt->fd[fd], NULL);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001061 FD_CLR(fd, fdt->close_on_exec);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 __put_unused_fd(files, fd);
1063 spin_unlock(&files->file_lock);
Ernie Petridesee731f42006-09-29 02:00:13 -07001064 retval = filp_close(filp, files);
1065
1066 /* can't restart close syscall because file table entry was cleared */
1067 if (unlikely(retval == -ERESTARTSYS ||
1068 retval == -ERESTARTNOINTR ||
1069 retval == -ERESTARTNOHAND ||
1070 retval == -ERESTART_RESTARTBLOCK))
1071 retval = -EINTR;
1072
1073 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074
1075out_unlock:
1076 spin_unlock(&files->file_lock);
1077 return -EBADF;
1078}
1079
1080EXPORT_SYMBOL(sys_close);
1081
1082/*
1083 * This routine simulates a hangup on the tty, to arrange that users
1084 * are given clean terminals at login time.
1085 */
1086asmlinkage long sys_vhangup(void)
1087{
1088 if (capable(CAP_SYS_TTY_CONFIG)) {
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001089 /* XXX: this needs locking */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 tty_vhangup(current->signal->tty);
1091 return 0;
1092 }
1093 return -EPERM;
1094}
1095
1096/*
1097 * Called when an inode is about to be open.
1098 * We use this to disallow opening large files on 32bit systems if
1099 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1100 * on this flag in sys_open.
1101 */
1102int generic_file_open(struct inode * inode, struct file * filp)
1103{
1104 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1105 return -EFBIG;
1106 return 0;
1107}
1108
1109EXPORT_SYMBOL(generic_file_open);
1110
1111/*
1112 * This is used by subsystems that don't want seekable
1113 * file descriptors
1114 */
1115int nonseekable_open(struct inode *inode, struct file *filp)
1116{
1117 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1118 return 0;
1119}
1120
1121EXPORT_SYMBOL(nonseekable_open);