blob: a4b12022edaa27cb8cd3ea865d14f1368d507660 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/quotaops.h>
Robert Love0eeca282005-07-12 17:06:03 -040011#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/tty.h>
15#include <linux/namei.h>
16#include <linux/backing-dev.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080017#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/security.h>
19#include <linux/mount.h>
20#include <linux/vfs.h>
Ulrich Drepper5590ff02006-01-18 17:43:53 -080021#include <linux/fcntl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <asm/uaccess.h>
23#include <linux/fs.h>
Yoav Zachef3daed2005-06-23 00:09:58 -070024#include <linux/personality.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/pagemap.h>
26#include <linux/syscalls.h>
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -070027#include <linux/rcupdate.h>
Amy Griffis73241cc2005-11-03 16:00:25 +000028#include <linux/audit.h>
Amit Arora97ac7352007-07-17 21:42:44 -040029#include <linux/falloc.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;
Jan Blunck4ac91372008-02-14 19:34:32 -0800130 error = vfs_statfs_native(nd.path.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
132 error = -EFAULT;
Jan Blunck1d957f92008-02-14 19:34:35 -0800133 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 }
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;
Jan Blunck4ac91372008-02-14 19:34:32 -0800149 error = vfs_statfs64(nd.path.dentry, &tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
151 error = -EFAULT;
Jan Blunck1d957f92008-02-14 19:34:35 -0800152 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 }
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
Linus Torvalds7b82dc02007-05-08 20:10:00 -0700214 /* Remove suid/sgid on truncate too */
215 newattrs.ia_valid |= should_remove_suid(dentry);
216
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800217 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800219 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return err;
221}
222
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800223static long do_sys_truncate(const char __user * path, loff_t length)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
225 struct nameidata nd;
226 struct inode * inode;
227 int error;
228
229 error = -EINVAL;
230 if (length < 0) /* sorry, but loff_t says... */
231 goto out;
232
233 error = user_path_walk(path, &nd);
234 if (error)
235 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -0800236 inode = nd.path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
239 error = -EISDIR;
240 if (S_ISDIR(inode->i_mode))
241 goto dput_and_out;
242
243 error = -EINVAL;
244 if (!S_ISREG(inode->i_mode))
245 goto dput_and_out;
246
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800247 error = vfs_permission(&nd, MAY_WRITE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 if (error)
249 goto dput_and_out;
250
251 error = -EROFS;
252 if (IS_RDONLY(inode))
253 goto dput_and_out;
254
255 error = -EPERM;
256 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
257 goto dput_and_out;
258
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 error = get_write_access(inode);
260 if (error)
261 goto dput_and_out;
262
david m. richter97003822007-07-31 00:39:12 -0700263 /*
264 * Make sure that there are no leases. get_write_access() protects
265 * against the truncate racing with a lease-granting setlease().
266 */
267 error = break_lease(inode, FMODE_WRITE);
268 if (error)
269 goto put_write_and_out;
270
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 error = locks_verify_truncate(inode, NULL, length);
272 if (!error) {
273 DQUOT_INIT(inode);
Jan Blunck4ac91372008-02-14 19:34:32 -0800274 error = do_truncate(nd.path.dentry, length, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
david m. richter97003822007-07-31 00:39:12 -0700277put_write_and_out:
278 put_write_access(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279dput_and_out:
Jan Blunck1d957f92008-02-14 19:34:35 -0800280 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281out:
282 return error;
283}
284
285asmlinkage long sys_truncate(const char __user * path, unsigned long length)
286{
287 /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
288 return do_sys_truncate(path, (long)length);
289}
290
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800291static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292{
293 struct inode * inode;
294 struct dentry *dentry;
295 struct file * file;
296 int error;
297
298 error = -EINVAL;
299 if (length < 0)
300 goto out;
301 error = -EBADF;
302 file = fget(fd);
303 if (!file)
304 goto out;
305
306 /* explicitly opened as large or we are on 64-bit box */
307 if (file->f_flags & O_LARGEFILE)
308 small = 0;
309
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800310 dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 inode = dentry->d_inode;
312 error = -EINVAL;
313 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
314 goto out_putf;
315
316 error = -EINVAL;
317 /* Cannot ftruncate over 2^31 bytes without large file support */
318 if (small && length > MAX_NON_LFS)
319 goto out_putf;
320
321 error = -EPERM;
322 if (IS_APPEND(inode))
323 goto out_putf;
324
325 error = locks_verify_truncate(inode, file, length);
326 if (!error)
Peter Staubach6e656be2006-06-25 05:48:36 -0700327 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328out_putf:
329 fput(file);
330out:
331 return error;
332}
333
334asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
335{
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700336 long ret = do_sys_ftruncate(fd, length, 1);
Linus Torvalds385910f2006-04-18 13:22:59 -0700337 /* avoid REGPARM breakage on x86: */
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700338 prevent_tail_call(ret);
339 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340}
341
342/* LFS versions of truncate are only needed on 32 bit machines */
343#if BITS_PER_LONG == 32
344asmlinkage long sys_truncate64(const char __user * path, loff_t length)
345{
346 return do_sys_truncate(path, length);
347}
348
349asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
350{
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700351 long ret = do_sys_ftruncate(fd, length, 0);
Linus Torvalds385910f2006-04-18 13:22:59 -0700352 /* avoid REGPARM breakage on x86: */
Linus Torvalds0a489cb2006-04-18 13:02:48 -0700353 prevent_tail_call(ret);
354 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355}
356#endif
357
Amit Arora97ac7352007-07-17 21:42:44 -0400358asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
359{
360 struct file *file;
361 struct inode *inode;
362 long ret = -EINVAL;
363
364 if (offset < 0 || len <= 0)
365 goto out;
366
367 /* Return error if mode is not supported */
368 ret = -EOPNOTSUPP;
369 if (mode && !(mode & FALLOC_FL_KEEP_SIZE))
370 goto out;
371
372 ret = -EBADF;
373 file = fget(fd);
374 if (!file)
375 goto out;
376 if (!(file->f_mode & FMODE_WRITE))
377 goto out_fput;
378 /*
379 * Revalidate the write permissions, in case security policy has
380 * changed since the files were opened.
381 */
382 ret = security_file_permission(file, MAY_WRITE);
383 if (ret)
384 goto out_fput;
385
386 inode = file->f_path.dentry->d_inode;
387
388 ret = -ESPIPE;
389 if (S_ISFIFO(inode->i_mode))
390 goto out_fput;
391
392 ret = -ENODEV;
393 /*
394 * Let individual file system decide if it supports preallocation
395 * for directories or not.
396 */
397 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
398 goto out_fput;
399
400 ret = -EFBIG;
401 /* Check for wrap through zero too */
402 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
403 goto out_fput;
404
405 if (inode->i_op && inode->i_op->fallocate)
406 ret = inode->i_op->fallocate(inode, mode, offset, len);
407 else
Ulrich Drepper0d786d42007-07-23 18:43:46 -0700408 ret = -EOPNOTSUPP;
Amit Arora97ac7352007-07-17 21:42:44 -0400409
410out_fput:
411 fput(file);
412out:
413 return ret;
414}
415
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416/*
417 * access() needs to use the real uid/gid, not the effective uid/gid.
418 * We do this by temporarily clearing all FS-related capabilities and
419 * switching the fsuid/fsgid around to the real ones.
420 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800421asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422{
423 struct nameidata nd;
424 int old_fsuid, old_fsgid;
425 kernel_cap_t old_cap;
426 int res;
427
428 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
429 return -EINVAL;
430
431 old_fsuid = current->fsuid;
432 old_fsgid = current->fsgid;
433 old_cap = current->cap_effective;
434
435 current->fsuid = current->uid;
436 current->fsgid = current->gid;
437
438 /*
439 * Clear the capabilities if we switch to a non-root user
440 *
441 * FIXME: There is a race here against sys_capset. The
442 * capabilities can change yet we will restore the old
443 * value below. We should hold task_capabilities_lock,
444 * but we cannot because user_path_walk can sleep.
445 */
446 if (current->uid)
447 cap_clear(current->cap_effective);
448 else
449 current->cap_effective = current->cap_permitted;
450
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800451 res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700452 if (res)
453 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
Dave Hansen6902d922006-09-30 23:29:01 -0700455 res = vfs_permission(&nd, mode);
456 /* SuS v2 requires we report a read only fs too */
457 if(res || !(mode & S_IWOTH) ||
Jan Blunck4ac91372008-02-14 19:34:32 -0800458 special_file(nd.path.dentry->d_inode->i_mode))
Dave Hansen6902d922006-09-30 23:29:01 -0700459 goto out_path_release;
460
Jan Blunck4ac91372008-02-14 19:34:32 -0800461 if(IS_RDONLY(nd.path.dentry->d_inode))
Dave Hansen6902d922006-09-30 23:29:01 -0700462 res = -EROFS;
463
464out_path_release:
Jan Blunck1d957f92008-02-14 19:34:35 -0800465 path_put(&nd.path);
Dave Hansen6902d922006-09-30 23:29:01 -0700466out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 current->fsuid = old_fsuid;
468 current->fsgid = old_fsgid;
469 current->cap_effective = old_cap;
470
471 return res;
472}
473
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800474asmlinkage long sys_access(const char __user *filename, int mode)
475{
476 return sys_faccessat(AT_FDCWD, filename, mode);
477}
478
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479asmlinkage long sys_chdir(const char __user * filename)
480{
481 struct nameidata nd;
482 int error;
483
Miklos Szeredi650a8982006-09-29 01:59:35 -0700484 error = __user_walk(filename,
485 LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 if (error)
487 goto out;
488
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800489 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 if (error)
491 goto dput_and_out;
492
Jan Blunckac748a02008-02-14 19:34:39 -0800493 set_fs_pwd(current->fs, &nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
495dput_and_out:
Jan Blunck1d957f92008-02-14 19:34:35 -0800496 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497out:
498 return error;
499}
500
501asmlinkage long sys_fchdir(unsigned int fd)
502{
503 struct file *file;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 int error;
506
507 error = -EBADF;
508 file = fget(fd);
509 if (!file)
510 goto out;
511
Jan Blunckac748a02008-02-14 19:34:39 -0800512 inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
514 error = -ENOTDIR;
515 if (!S_ISDIR(inode->i_mode))
516 goto out_putf;
517
Christoph Hellwig8c744fb2005-11-08 21:35:04 -0800518 error = file_permission(file, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 if (!error)
Jan Blunckac748a02008-02-14 19:34:39 -0800520 set_fs_pwd(current->fs, &file->f_path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521out_putf:
522 fput(file);
523out:
524 return error;
525}
526
527asmlinkage long sys_chroot(const char __user * filename)
528{
529 struct nameidata nd;
530 int error;
531
532 error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
533 if (error)
534 goto out;
535
Christoph Hellwige4543ed2005-11-08 21:35:04 -0800536 error = vfs_permission(&nd, MAY_EXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 if (error)
538 goto dput_and_out;
539
540 error = -EPERM;
541 if (!capable(CAP_SYS_CHROOT))
542 goto dput_and_out;
543
Jan Blunckac748a02008-02-14 19:34:39 -0800544 set_fs_root(current->fs, &nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 set_fs_altroot();
546 error = 0;
547dput_and_out:
Jan Blunck1d957f92008-02-14 19:34:35 -0800548 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549out:
550 return error;
551}
552
553asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
554{
555 struct inode * inode;
556 struct dentry * dentry;
557 struct file * file;
558 int err = -EBADF;
559 struct iattr newattrs;
560
561 file = fget(fd);
562 if (!file)
563 goto out;
564
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800565 dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 inode = dentry->d_inode;
567
Al Viro5a190ae2007-06-07 12:19:32 -0400568 audit_inode(NULL, dentry);
Amy Griffis73241cc2005-11-03 16:00:25 +0000569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 err = -EROFS;
571 if (IS_RDONLY(inode))
572 goto out_putf;
573 err = -EPERM;
574 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
575 goto out_putf;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800576 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 if (mode == (mode_t) -1)
578 mode = inode->i_mode;
579 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
580 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
581 err = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800582 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584out_putf:
585 fput(file);
586out:
587 return err;
588}
589
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800590asmlinkage long sys_fchmodat(int dfd, const char __user *filename,
591 mode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592{
593 struct nameidata nd;
594 struct inode * inode;
595 int error;
596 struct iattr newattrs;
597
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800598 error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 if (error)
600 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -0800601 inode = nd.path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
603 error = -EROFS;
604 if (IS_RDONLY(inode))
605 goto dput_and_out;
606
607 error = -EPERM;
608 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
609 goto dput_and_out;
610
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800611 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 if (mode == (mode_t) -1)
613 mode = inode->i_mode;
614 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
615 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
Jan Blunck4ac91372008-02-14 19:34:32 -0800616 error = notify_change(nd.path.dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800617 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619dput_and_out:
Jan Blunck1d957f92008-02-14 19:34:35 -0800620 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621out:
622 return error;
623}
624
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800625asmlinkage long sys_chmod(const char __user *filename, mode_t mode)
626{
627 return sys_fchmodat(AT_FDCWD, filename, mode);
628}
629
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
631{
632 struct inode * inode;
633 int error;
634 struct iattr newattrs;
635
636 error = -ENOENT;
637 if (!(inode = dentry->d_inode)) {
638 printk(KERN_ERR "chown_common: NULL inode\n");
639 goto out;
640 }
641 error = -EROFS;
642 if (IS_RDONLY(inode))
643 goto out;
644 error = -EPERM;
645 if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
646 goto out;
647 newattrs.ia_valid = ATTR_CTIME;
648 if (user != (uid_t) -1) {
649 newattrs.ia_valid |= ATTR_UID;
650 newattrs.ia_uid = user;
651 }
652 if (group != (gid_t) -1) {
653 newattrs.ia_valid |= ATTR_GID;
654 newattrs.ia_gid = group;
655 }
656 if (!S_ISDIR(inode->i_mode))
Serge E. Hallynb5376772007-10-16 23:31:36 -0700657 newattrs.ia_valid |=
658 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800659 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 error = notify_change(dentry, &newattrs);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800661 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662out:
663 return error;
664}
665
666asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
667{
668 struct nameidata nd;
669 int error;
670
671 error = user_path_walk(filename, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700672 if (error)
673 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -0800674 error = chown_common(nd.path.dentry, user, group);
Jan Blunck1d957f92008-02-14 19:34:35 -0800675 path_put(&nd.path);
Dave Hansen6902d922006-09-30 23:29:01 -0700676out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 return error;
678}
679
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800680asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
681 gid_t group, int flag)
682{
683 struct nameidata nd;
684 int error = -EINVAL;
685 int follow;
686
687 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
688 goto out;
689
690 follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
691 error = __user_walk_fd(dfd, filename, follow, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700692 if (error)
693 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -0800694 error = chown_common(nd.path.dentry, user, group);
Jan Blunck1d957f92008-02-14 19:34:35 -0800695 path_put(&nd.path);
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800696out:
697 return error;
698}
699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group)
701{
702 struct nameidata nd;
703 int error;
704
705 error = user_path_walk_link(filename, &nd);
Dave Hansen6902d922006-09-30 23:29:01 -0700706 if (error)
707 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -0800708 error = chown_common(nd.path.dentry, user, group);
Jan Blunck1d957f92008-02-14 19:34:35 -0800709 path_put(&nd.path);
Dave Hansen6902d922006-09-30 23:29:01 -0700710out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 return error;
712}
713
714
715asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
716{
717 struct file * file;
718 int error = -EBADF;
Dave Hansen6902d922006-09-30 23:29:01 -0700719 struct dentry * dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
721 file = fget(fd);
Dave Hansen6902d922006-09-30 23:29:01 -0700722 if (!file)
723 goto out;
724
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800725 dentry = file->f_path.dentry;
Al Viro5a190ae2007-06-07 12:19:32 -0400726 audit_inode(NULL, dentry);
Dave Hansen6902d922006-09-30 23:29:01 -0700727 error = chown_common(dentry, user, group);
728 fput(file);
729out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 return error;
731}
732
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700733static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
Trond Myklebust834f2a42005-10-18 14:20:16 -0700734 int flags, struct file *f,
735 int (*open)(struct inode *, struct file *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 struct inode *inode;
738 int error;
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 f->f_flags = flags;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700741 f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
742 FMODE_PREAD | FMODE_PWRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 inode = dentry->d_inode;
744 if (f->f_mode & FMODE_WRITE) {
745 error = get_write_access(inode);
746 if (error)
747 goto cleanup_file;
748 }
749
750 f->f_mapping = inode->i_mapping;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800751 f->f_path.dentry = dentry;
752 f->f_path.mnt = mnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 f->f_pos = 0;
754 f->f_op = fops_get(inode->i_fop);
755 file_move(f, &inode->i_sb->s_files);
756
Yuichi Nakamura788e7dd2007-09-14 09:27:07 +0900757 error = security_dentry_open(f);
758 if (error)
759 goto cleanup_all;
760
Trond Myklebust834f2a42005-10-18 14:20:16 -0700761 if (!open && f->f_op)
762 open = f->f_op->open;
763 if (open) {
764 error = open(inode, f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 if (error)
766 goto cleanup_all;
767 }
Trond Myklebust834f2a42005-10-18 14:20:16 -0700768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
770
771 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
772
773 /* NB: we're sure to have correct a_ops only after f_op->open */
774 if (f->f_flags & O_DIRECT) {
Carsten Otteceffc072005-06-23 22:05:25 -0700775 if (!f->f_mapping->a_ops ||
776 ((!f->f_mapping->a_ops->direct_IO) &&
777 (!f->f_mapping->a_ops->get_xip_page))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 fput(f);
779 f = ERR_PTR(-EINVAL);
780 }
781 }
782
783 return f;
784
785cleanup_all:
786 fops_put(f->f_op);
787 if (f->f_mode & FMODE_WRITE)
788 put_write_access(inode);
789 file_kill(f);
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800790 f->f_path.dentry = NULL;
791 f->f_path.mnt = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792cleanup_file:
793 put_filp(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 dput(dentry);
795 mntput(mnt);
796 return ERR_PTR(error);
797}
798
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700799/*
800 * Note that while the flag value (low two bits) for sys_open means:
801 * 00 - read-only
802 * 01 - write-only
803 * 10 - read-write
804 * 11 - special
805 * it is changed into
806 * 00 - no permissions needed
807 * 01 - read-permission
808 * 10 - write-permission
809 * 11 - read-write
810 * for the internal routines (ie open_namei()/follow_link() etc). 00 is
811 * used by symlinks.
812 */
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800813static struct file *do_filp_open(int dfd, const char *filename, int flags,
814 int mode)
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700815{
816 int namei_flags, error;
817 struct nameidata nd;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700818
819 namei_flags = flags;
820 if ((namei_flags+1) & O_ACCMODE)
821 namei_flags++;
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700822
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800823 error = open_namei(dfd, filename, namei_flags, mode, &nd);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700824 if (!error)
Trond Myklebust834f2a42005-10-18 14:20:16 -0700825 return nameidata_to_filp(&nd, flags);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700826
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700827 return ERR_PTR(error);
828}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800829
830struct file *filp_open(const char *filename, int flags, int mode)
831{
832 return do_filp_open(AT_FDCWD, filename, flags, mode);
833}
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700834EXPORT_SYMBOL(filp_open);
835
Trond Myklebust834f2a42005-10-18 14:20:16 -0700836/**
837 * lookup_instantiate_filp - instantiates the open intent filp
838 * @nd: pointer to nameidata
839 * @dentry: pointer to dentry
840 * @open: open callback
841 *
842 * Helper for filesystems that want to use lookup open intents and pass back
843 * a fully instantiated struct file to the caller.
844 * This function is meant to be called from within a filesystem's
845 * lookup method.
Oleg Drokin9a56c212006-03-25 03:07:02 -0800846 * Beware of calling it for non-regular files! Those ->open methods might block
847 * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo,
848 * leading to a deadlock, as nobody can open that fifo anymore, because
849 * another process to open fifo will block on locked parent when doing lookup).
Trond Myklebust834f2a42005-10-18 14:20:16 -0700850 * Note that in case of error, nd->intent.open.file is destroyed, but the
851 * path information remains valid.
852 * If the open callback is set to NULL, then the standard f_op->open()
853 * filesystem callback is substituted.
854 */
855struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
856 int (*open)(struct inode *, struct file *))
857{
858 if (IS_ERR(nd->intent.open.file))
859 goto out;
860 if (IS_ERR(dentry))
861 goto out_err;
Jan Blunck4ac91372008-02-14 19:34:32 -0800862 nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
Trond Myklebust834f2a42005-10-18 14:20:16 -0700863 nd->intent.open.flags - 1,
864 nd->intent.open.file,
865 open);
866out:
867 return nd->intent.open.file;
868out_err:
869 release_open_intent(nd);
870 nd->intent.open.file = (struct file *)dentry;
871 goto out;
872}
873EXPORT_SYMBOL_GPL(lookup_instantiate_filp);
874
875/**
876 * nameidata_to_filp - convert a nameidata to an open filp.
877 * @nd: pointer to nameidata
878 * @flags: open flags
879 *
880 * Note that this function destroys the original nameidata
881 */
882struct file *nameidata_to_filp(struct nameidata *nd, int flags)
883{
884 struct file *filp;
885
886 /* Pick up the filp from the open intent */
887 filp = nd->intent.open.file;
888 /* Has the filesystem initialised the file for us? */
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800889 if (filp->f_path.dentry == NULL)
Jan Blunck4ac91372008-02-14 19:34:32 -0800890 filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp,
891 NULL);
Trond Myklebust834f2a42005-10-18 14:20:16 -0700892 else
Jan Blunck1d957f92008-02-14 19:34:35 -0800893 path_put(&nd->path);
Trond Myklebust834f2a42005-10-18 14:20:16 -0700894 return filp;
895}
896
Peter Staubach6fdcc212005-11-07 00:59:42 -0800897/*
898 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
899 * error.
900 */
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700901struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
902{
903 int error;
904 struct file *f;
905
Christoph Hellwig322ee5b2008-02-15 14:37:24 -0800906 /*
907 * We must always pass in a valid mount pointer. Historically
908 * callers got away with not passing it, but we must enforce this at
909 * the earliest possible point now to avoid strange problems deep in the
910 * filesystem stack.
911 */
912 if (!mnt) {
913 printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
914 dump_stack();
915 return ERR_PTR(-EINVAL);
916 }
917
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700918 error = -ENFILE;
919 f = get_empty_filp();
Peter Staubach6fdcc212005-11-07 00:59:42 -0800920 if (f == NULL) {
921 dput(dentry);
922 mntput(mnt);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700923 return ERR_PTR(error);
Peter Staubach6fdcc212005-11-07 00:59:42 -0800924 }
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700925
Trond Myklebust834f2a42005-10-18 14:20:16 -0700926 return __dentry_open(dentry, mnt, flags, f, NULL);
Peter Staubacha1a5b3d2005-09-13 01:25:12 -0700927}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928EXPORT_SYMBOL(dentry_open);
929
930/*
931 * Find an empty file descriptor entry, and mark it busy.
932 */
Ulrich Drepper4a195422007-07-15 23:40:34 -0700933int get_unused_fd_flags(int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934{
935 struct files_struct * files = current->files;
936 int fd, error;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700937 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938
939 error = -EMFILE;
940 spin_lock(&files->file_lock);
941
942repeat:
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700943 fdt = files_fdtable(files);
Vadim Lobanovbbea9f62006-12-10 02:21:12 -0800944 fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds,
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800945 files->next_fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
947 /*
948 * N.B. For clone tasks sharing a files structure, this test
949 * will limit the total number of files that can be opened.
950 */
951 if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
952 goto out;
953
954 /* Do we need to expand the fd array or fd set? */
955 error = expand_files(files, fd);
956 if (error < 0)
957 goto out;
958
959 if (error) {
960 /*
961 * If we needed to expand the fs array we
962 * might have blocked - try again.
963 */
964 error = -EMFILE;
965 goto repeat;
966 }
967
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700968 FD_SET(fd, fdt->open_fds);
Ulrich Drepperf23513e2007-07-15 23:40:32 -0700969 if (flags & O_CLOEXEC)
970 FD_SET(fd, fdt->close_on_exec);
971 else
972 FD_CLR(fd, fdt->close_on_exec);
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800973 files->next_fd = fd + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974#if 1
975 /* Sanity check */
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700976 if (fdt->fd[fd] != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700978 fdt->fd[fd] = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 }
980#endif
981 error = fd;
982
983out:
984 spin_unlock(&files->file_lock);
985 return error;
986}
987
Ulrich Drepperf23513e2007-07-15 23:40:32 -0700988int get_unused_fd(void)
989{
990 return get_unused_fd_flags(0);
991}
992
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993EXPORT_SYMBOL(get_unused_fd);
994
Matt Mackallb01ec0e2006-01-08 01:05:20 -0800995static void __put_unused_fd(struct files_struct *files, unsigned int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996{
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700997 struct fdtable *fdt = files_fdtable(files);
998 __FD_CLR(fd, fdt->open_fds);
Eric Dumazet0c9e63f2006-03-23 03:00:12 -0800999 if (fd < files->next_fd)
1000 files->next_fd = fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001}
1002
Harvey Harrisonfc9b52c2008-02-08 04:19:52 -08001003void put_unused_fd(unsigned int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004{
1005 struct files_struct *files = current->files;
1006 spin_lock(&files->file_lock);
1007 __put_unused_fd(files, fd);
1008 spin_unlock(&files->file_lock);
1009}
1010
1011EXPORT_SYMBOL(put_unused_fd);
1012
1013/*
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001014 * Install a file pointer in the fd array.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 *
1016 * The VFS is full of places where we drop the files lock between
1017 * setting the open_fds bitmap and installing the file in the file
1018 * array. At any such point, we are vulnerable to a dup2() race
1019 * installing a file in the array before us. We need to detect this and
1020 * fput() the struct file we are about to overwrite in this case.
1021 *
1022 * It should never happen - if we allow dup2() do it, _really_ bad things
1023 * will follow.
1024 */
1025
Harvey Harrisonfc9b52c2008-02-08 04:19:52 -08001026void fd_install(unsigned int fd, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027{
1028 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001029 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001031 fdt = files_fdtable(files);
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -07001032 BUG_ON(fdt->fd[fd] != NULL);
1033 rcu_assign_pointer(fdt->fd[fd], file);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 spin_unlock(&files->file_lock);
1035}
1036
1037EXPORT_SYMBOL(fd_install);
1038
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001039long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040{
Miklos Szeredie922efc2005-09-06 15:18:25 -07001041 char *tmp = getname(filename);
1042 int fd = PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 if (!IS_ERR(tmp)) {
Ulrich Drepperf23513e2007-07-15 23:40:32 -07001045 fd = get_unused_fd_flags(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 if (fd >= 0) {
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001047 struct file *f = do_filp_open(dfd, tmp, flags, mode);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -07001048 if (IS_ERR(f)) {
1049 put_unused_fd(fd);
1050 fd = PTR_ERR(f);
1051 } else {
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001052 fsnotify_open(f->f_path.dentry);
Telemaque Ndizihiwefed2fc12005-06-23 00:10:33 -07001053 fd_install(fd, f);
1054 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 putname(tmp);
1057 }
1058 return fd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059}
Miklos Szeredie922efc2005-09-06 15:18:25 -07001060
1061asmlinkage long sys_open(const char __user *filename, int flags, int mode)
1062{
Linus Torvalds385910f2006-04-18 13:22:59 -07001063 long ret;
1064
Miklos Szeredie922efc2005-09-06 15:18:25 -07001065 if (force_o_largefile())
1066 flags |= O_LARGEFILE;
1067
Linus Torvalds385910f2006-04-18 13:22:59 -07001068 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
1069 /* avoid REGPARM breakage on x86: */
1070 prevent_tail_call(ret);
1071 return ret;
Miklos Szeredie922efc2005-09-06 15:18:25 -07001072}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001074asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
1075 int mode)
1076{
Linus Torvalds385910f2006-04-18 13:22:59 -07001077 long ret;
1078
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001079 if (force_o_largefile())
1080 flags |= O_LARGEFILE;
1081
Linus Torvalds385910f2006-04-18 13:22:59 -07001082 ret = do_sys_open(dfd, filename, flags, mode);
1083 /* avoid REGPARM breakage on x86: */
1084 prevent_tail_call(ret);
1085 return ret;
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001086}
Ulrich Drepper5590ff02006-01-18 17:43:53 -08001087
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088#ifndef __alpha__
1089
1090/*
1091 * For backward compatibility? Maybe this should be moved
1092 * into arch/i386 instead?
1093 */
1094asmlinkage long sys_creat(const char __user * pathname, int mode)
1095{
1096 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1097}
1098
1099#endif
1100
1101/*
1102 * "id" is the POSIX thread ID. We use the
1103 * files pointer for this..
1104 */
1105int filp_close(struct file *filp, fl_owner_t id)
1106{
Christoph Lameter45778ca2005-06-23 00:10:17 -07001107 int retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108
1109 if (!file_count(filp)) {
1110 printk(KERN_ERR "VFS: Close: file count is 0\n");
Christoph Lameter45778ca2005-06-23 00:10:17 -07001111 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 }
1113
Christoph Lameter45778ca2005-06-23 00:10:17 -07001114 if (filp->f_op && filp->f_op->flush)
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -07001115 retval = filp->f_op->flush(filp, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116
1117 dnotify_flush(filp, id);
1118 locks_remove_posix(filp, id);
1119 fput(filp);
1120 return retval;
1121}
1122
1123EXPORT_SYMBOL(filp_close);
1124
1125/*
1126 * Careful here! We test whether the file pointer is NULL before
1127 * releasing the fd. This ensures that one clone task can't release
1128 * an fd while another clone is opening it.
1129 */
1130asmlinkage long sys_close(unsigned int fd)
1131{
1132 struct file * filp;
1133 struct files_struct *files = current->files;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001134 struct fdtable *fdt;
Ernie Petridesee731f42006-09-29 02:00:13 -07001135 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136
1137 spin_lock(&files->file_lock);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001138 fdt = files_fdtable(files);
1139 if (fd >= fdt->max_fds)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 goto out_unlock;
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001141 filp = fdt->fd[fd];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 if (!filp)
1143 goto out_unlock;
Dipankar Sarmaab2af1f2005-09-09 13:04:13 -07001144 rcu_assign_pointer(fdt->fd[fd], NULL);
Dipankar Sarmabadf1662005-09-09 13:04:10 -07001145 FD_CLR(fd, fdt->close_on_exec);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 __put_unused_fd(files, fd);
1147 spin_unlock(&files->file_lock);
Ernie Petridesee731f42006-09-29 02:00:13 -07001148 retval = filp_close(filp, files);
1149
1150 /* can't restart close syscall because file table entry was cleared */
1151 if (unlikely(retval == -ERESTARTSYS ||
1152 retval == -ERESTARTNOINTR ||
1153 retval == -ERESTARTNOHAND ||
1154 retval == -ERESTART_RESTARTBLOCK))
1155 retval = -EINTR;
1156
1157 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158
1159out_unlock:
1160 spin_unlock(&files->file_lock);
1161 return -EBADF;
1162}
1163
1164EXPORT_SYMBOL(sys_close);
1165
1166/*
1167 * This routine simulates a hangup on the tty, to arrange that users
1168 * are given clean terminals at login time.
1169 */
1170asmlinkage long sys_vhangup(void)
1171{
1172 if (capable(CAP_SYS_TTY_CONFIG)) {
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001173 /* XXX: this needs locking */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 tty_vhangup(current->signal->tty);
1175 return 0;
1176 }
1177 return -EPERM;
1178}
1179
1180/*
1181 * Called when an inode is about to be open.
1182 * We use this to disallow opening large files on 32bit systems if
1183 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1184 * on this flag in sys_open.
1185 */
1186int generic_file_open(struct inode * inode, struct file * filp)
1187{
1188 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
Alan Coxa9c62a12007-10-16 23:30:22 -07001189 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 return 0;
1191}
1192
1193EXPORT_SYMBOL(generic_file_open);
1194
1195/*
1196 * This is used by subsystems that don't want seekable
1197 * file descriptors
1198 */
1199int nonseekable_open(struct inode *inode, struct file *filp)
1200{
1201 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1202 return 0;
1203}
1204
1205EXPORT_SYMBOL(nonseekable_open);