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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/stat.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/config.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/file.h> | |
12 | #include <linux/smp_lock.h> | |
13 | #include <linux/highuid.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/syscalls.h> | |
18 | ||
19 | #include <asm/uaccess.h> | |
20 | #include <asm/unistd.h> | |
21 | ||
22 | void generic_fillattr(struct inode *inode, struct kstat *stat) | |
23 | { | |
24 | stat->dev = inode->i_sb->s_dev; | |
25 | stat->ino = inode->i_ino; | |
26 | stat->mode = inode->i_mode; | |
27 | stat->nlink = inode->i_nlink; | |
28 | stat->uid = inode->i_uid; | |
29 | stat->gid = inode->i_gid; | |
30 | stat->rdev = inode->i_rdev; | |
31 | stat->atime = inode->i_atime; | |
32 | stat->mtime = inode->i_mtime; | |
33 | stat->ctime = inode->i_ctime; | |
34 | stat->size = i_size_read(inode); | |
35 | stat->blocks = inode->i_blocks; | |
36 | stat->blksize = inode->i_blksize; | |
37 | } | |
38 | ||
39 | EXPORT_SYMBOL(generic_fillattr); | |
40 | ||
41 | int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) | |
42 | { | |
43 | struct inode *inode = dentry->d_inode; | |
44 | int retval; | |
45 | ||
46 | retval = security_inode_getattr(mnt, dentry); | |
47 | if (retval) | |
48 | return retval; | |
49 | ||
50 | if (inode->i_op->getattr) | |
51 | return inode->i_op->getattr(mnt, dentry, stat); | |
52 | ||
53 | generic_fillattr(inode, stat); | |
54 | if (!stat->blksize) { | |
55 | struct super_block *s = inode->i_sb; | |
56 | unsigned blocks; | |
57 | blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits; | |
58 | stat->blocks = (s->s_blocksize / 512) * blocks; | |
59 | stat->blksize = s->s_blocksize; | |
60 | } | |
61 | return 0; | |
62 | } | |
63 | ||
64 | EXPORT_SYMBOL(vfs_getattr); | |
65 | ||
66 | int vfs_stat(char __user *name, struct kstat *stat) | |
67 | { | |
68 | struct nameidata nd; | |
69 | int error; | |
70 | ||
71 | error = user_path_walk(name, &nd); | |
72 | if (!error) { | |
73 | error = vfs_getattr(nd.mnt, nd.dentry, stat); | |
74 | path_release(&nd); | |
75 | } | |
76 | return error; | |
77 | } | |
78 | ||
79 | EXPORT_SYMBOL(vfs_stat); | |
80 | ||
81 | int vfs_lstat(char __user *name, struct kstat *stat) | |
82 | { | |
83 | struct nameidata nd; | |
84 | int error; | |
85 | ||
86 | error = user_path_walk_link(name, &nd); | |
87 | if (!error) { | |
88 | error = vfs_getattr(nd.mnt, nd.dentry, stat); | |
89 | path_release(&nd); | |
90 | } | |
91 | return error; | |
92 | } | |
93 | ||
94 | EXPORT_SYMBOL(vfs_lstat); | |
95 | ||
96 | int vfs_fstat(unsigned int fd, struct kstat *stat) | |
97 | { | |
98 | struct file *f = fget(fd); | |
99 | int error = -EBADF; | |
100 | ||
101 | if (f) { | |
102 | error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat); | |
103 | fput(f); | |
104 | } | |
105 | return error; | |
106 | } | |
107 | ||
108 | EXPORT_SYMBOL(vfs_fstat); | |
109 | ||
110 | #ifdef __ARCH_WANT_OLD_STAT | |
111 | ||
112 | /* | |
113 | * For backward compatibility? Maybe this should be moved | |
114 | * into arch/i386 instead? | |
115 | */ | |
116 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
117 | { | |
118 | static int warncount = 5; | |
119 | struct __old_kernel_stat tmp; | |
120 | ||
121 | if (warncount > 0) { | |
122 | warncount--; | |
123 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
124 | current->comm); | |
125 | } else if (warncount < 0) { | |
126 | /* it's laughable, but... */ | |
127 | warncount = 0; | |
128 | } | |
129 | ||
130 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
131 | tmp.st_dev = old_encode_dev(stat->dev); | |
132 | tmp.st_ino = stat->ino; | |
133 | tmp.st_mode = stat->mode; | |
134 | tmp.st_nlink = stat->nlink; | |
135 | if (tmp.st_nlink != stat->nlink) | |
136 | return -EOVERFLOW; | |
137 | SET_UID(tmp.st_uid, stat->uid); | |
138 | SET_GID(tmp.st_gid, stat->gid); | |
139 | tmp.st_rdev = old_encode_dev(stat->rdev); | |
140 | #if BITS_PER_LONG == 32 | |
141 | if (stat->size > MAX_NON_LFS) | |
142 | return -EOVERFLOW; | |
143 | #endif | |
144 | tmp.st_size = stat->size; | |
145 | tmp.st_atime = stat->atime.tv_sec; | |
146 | tmp.st_mtime = stat->mtime.tv_sec; | |
147 | tmp.st_ctime = stat->ctime.tv_sec; | |
148 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
149 | } | |
150 | ||
151 | asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf) | |
152 | { | |
153 | struct kstat stat; | |
154 | int error = vfs_stat(filename, &stat); | |
155 | ||
156 | if (!error) | |
157 | error = cp_old_stat(&stat, statbuf); | |
158 | ||
159 | return error; | |
160 | } | |
161 | asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf) | |
162 | { | |
163 | struct kstat stat; | |
164 | int error = vfs_lstat(filename, &stat); | |
165 | ||
166 | if (!error) | |
167 | error = cp_old_stat(&stat, statbuf); | |
168 | ||
169 | return error; | |
170 | } | |
171 | asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf) | |
172 | { | |
173 | struct kstat stat; | |
174 | int error = vfs_fstat(fd, &stat); | |
175 | ||
176 | if (!error) | |
177 | error = cp_old_stat(&stat, statbuf); | |
178 | ||
179 | return error; | |
180 | } | |
181 | ||
182 | #endif /* __ARCH_WANT_OLD_STAT */ | |
183 | ||
184 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) | |
185 | { | |
186 | struct stat tmp; | |
187 | ||
188 | #if BITS_PER_LONG == 32 | |
189 | if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) | |
190 | return -EOVERFLOW; | |
191 | #else | |
192 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) | |
193 | return -EOVERFLOW; | |
194 | #endif | |
195 | ||
196 | memset(&tmp, 0, sizeof(tmp)); | |
197 | #if BITS_PER_LONG == 32 | |
198 | tmp.st_dev = old_encode_dev(stat->dev); | |
199 | #else | |
200 | tmp.st_dev = new_encode_dev(stat->dev); | |
201 | #endif | |
202 | tmp.st_ino = stat->ino; | |
203 | tmp.st_mode = stat->mode; | |
204 | tmp.st_nlink = stat->nlink; | |
205 | if (tmp.st_nlink != stat->nlink) | |
206 | return -EOVERFLOW; | |
207 | SET_UID(tmp.st_uid, stat->uid); | |
208 | SET_GID(tmp.st_gid, stat->gid); | |
209 | #if BITS_PER_LONG == 32 | |
210 | tmp.st_rdev = old_encode_dev(stat->rdev); | |
211 | #else | |
212 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
213 | #endif | |
214 | #if BITS_PER_LONG == 32 | |
215 | if (stat->size > MAX_NON_LFS) | |
216 | return -EOVERFLOW; | |
217 | #endif | |
218 | tmp.st_size = stat->size; | |
219 | tmp.st_atime = stat->atime.tv_sec; | |
220 | tmp.st_mtime = stat->mtime.tv_sec; | |
221 | tmp.st_ctime = stat->ctime.tv_sec; | |
222 | #ifdef STAT_HAVE_NSEC | |
223 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
224 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
225 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
226 | #endif | |
227 | tmp.st_blocks = stat->blocks; | |
228 | tmp.st_blksize = stat->blksize; | |
229 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
230 | } | |
231 | ||
232 | asmlinkage long sys_newstat(char __user * filename, struct stat __user * statbuf) | |
233 | { | |
234 | struct kstat stat; | |
235 | int error = vfs_stat(filename, &stat); | |
236 | ||
237 | if (!error) | |
238 | error = cp_new_stat(&stat, statbuf); | |
239 | ||
240 | return error; | |
241 | } | |
242 | asmlinkage long sys_newlstat(char __user * filename, struct stat __user * statbuf) | |
243 | { | |
244 | struct kstat stat; | |
245 | int error = vfs_lstat(filename, &stat); | |
246 | ||
247 | if (!error) | |
248 | error = cp_new_stat(&stat, statbuf); | |
249 | ||
250 | return error; | |
251 | } | |
252 | asmlinkage long sys_newfstat(unsigned int fd, struct stat __user * statbuf) | |
253 | { | |
254 | struct kstat stat; | |
255 | int error = vfs_fstat(fd, &stat); | |
256 | ||
257 | if (!error) | |
258 | error = cp_new_stat(&stat, statbuf); | |
259 | ||
260 | return error; | |
261 | } | |
262 | ||
263 | asmlinkage long sys_readlink(const char __user * path, char __user * buf, int bufsiz) | |
264 | { | |
265 | struct nameidata nd; | |
266 | int error; | |
267 | ||
268 | if (bufsiz <= 0) | |
269 | return -EINVAL; | |
270 | ||
271 | error = user_path_walk_link(path, &nd); | |
272 | if (!error) { | |
273 | struct inode * inode = nd.dentry->d_inode; | |
274 | ||
275 | error = -EINVAL; | |
276 | if (inode->i_op && inode->i_op->readlink) { | |
277 | error = security_inode_readlink(nd.dentry); | |
278 | if (!error) { | |
279 | touch_atime(nd.mnt, nd.dentry); | |
280 | error = inode->i_op->readlink(nd.dentry, buf, bufsiz); | |
281 | } | |
282 | } | |
283 | path_release(&nd); | |
284 | } | |
285 | return error; | |
286 | } | |
287 | ||
288 | ||
289 | /* ---------- LFS-64 ----------- */ | |
290 | #ifdef __ARCH_WANT_STAT64 | |
291 | ||
292 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) | |
293 | { | |
294 | struct stat64 tmp; | |
295 | ||
296 | memset(&tmp, 0, sizeof(struct stat64)); | |
297 | #ifdef CONFIG_MIPS | |
298 | /* mips has weird padding, so we don't get 64 bits there */ | |
299 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) | |
300 | return -EOVERFLOW; | |
301 | tmp.st_dev = new_encode_dev(stat->dev); | |
302 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
303 | #else | |
304 | tmp.st_dev = huge_encode_dev(stat->dev); | |
305 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
306 | #endif | |
307 | tmp.st_ino = stat->ino; | |
308 | #ifdef STAT64_HAS_BROKEN_ST_INO | |
309 | tmp.__st_ino = stat->ino; | |
310 | #endif | |
311 | tmp.st_mode = stat->mode; | |
312 | tmp.st_nlink = stat->nlink; | |
313 | tmp.st_uid = stat->uid; | |
314 | tmp.st_gid = stat->gid; | |
315 | tmp.st_atime = stat->atime.tv_sec; | |
316 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
317 | tmp.st_mtime = stat->mtime.tv_sec; | |
318 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
319 | tmp.st_ctime = stat->ctime.tv_sec; | |
320 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
321 | tmp.st_size = stat->size; | |
322 | tmp.st_blocks = stat->blocks; | |
323 | tmp.st_blksize = stat->blksize; | |
324 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
325 | } | |
326 | ||
327 | asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf) | |
328 | { | |
329 | struct kstat stat; | |
330 | int error = vfs_stat(filename, &stat); | |
331 | ||
332 | if (!error) | |
333 | error = cp_new_stat64(&stat, statbuf); | |
334 | ||
335 | return error; | |
336 | } | |
337 | asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf) | |
338 | { | |
339 | struct kstat stat; | |
340 | int error = vfs_lstat(filename, &stat); | |
341 | ||
342 | if (!error) | |
343 | error = cp_new_stat64(&stat, statbuf); | |
344 | ||
345 | return error; | |
346 | } | |
347 | asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) | |
348 | { | |
349 | struct kstat stat; | |
350 | int error = vfs_fstat(fd, &stat); | |
351 | ||
352 | if (!error) | |
353 | error = cp_new_stat64(&stat, statbuf); | |
354 | ||
355 | return error; | |
356 | } | |
357 | ||
358 | #endif /* __ARCH_WANT_STAT64 */ | |
359 | ||
360 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
361 | { | |
362 | spin_lock(&inode->i_lock); | |
363 | inode->i_blocks += bytes >> 9; | |
364 | bytes &= 511; | |
365 | inode->i_bytes += bytes; | |
366 | if (inode->i_bytes >= 512) { | |
367 | inode->i_blocks++; | |
368 | inode->i_bytes -= 512; | |
369 | } | |
370 | spin_unlock(&inode->i_lock); | |
371 | } | |
372 | ||
373 | EXPORT_SYMBOL(inode_add_bytes); | |
374 | ||
375 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
376 | { | |
377 | spin_lock(&inode->i_lock); | |
378 | inode->i_blocks -= bytes >> 9; | |
379 | bytes &= 511; | |
380 | if (inode->i_bytes < bytes) { | |
381 | inode->i_blocks--; | |
382 | inode->i_bytes += 512; | |
383 | } | |
384 | inode->i_bytes -= bytes; | |
385 | spin_unlock(&inode->i_lock); | |
386 | } | |
387 | ||
388 | EXPORT_SYMBOL(inode_sub_bytes); | |
389 | ||
390 | loff_t inode_get_bytes(struct inode *inode) | |
391 | { | |
392 | loff_t ret; | |
393 | ||
394 | spin_lock(&inode->i_lock); | |
395 | ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; | |
396 | spin_unlock(&inode->i_lock); | |
397 | return ret; | |
398 | } | |
399 | ||
400 | EXPORT_SYMBOL(inode_get_bytes); | |
401 | ||
402 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
403 | { | |
404 | /* Caller is here responsible for sufficient locking | |
405 | * (ie. inode->i_lock) */ | |
406 | inode->i_blocks = bytes >> 9; | |
407 | inode->i_bytes = bytes & 511; | |
408 | } | |
409 | ||
410 | EXPORT_SYMBOL(inode_set_bytes); |