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1/*
2 * linux/fs/stat.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7#include <linux/export.h>
8#include <linux/mm.h>
9#include <linux/errno.h>
10#include <linux/file.h>
11#include <linux/highuid.h>
12#include <linux/fs.h>
13#include <linux/namei.h>
14#include <linux/security.h>
15#include <linux/syscalls.h>
16#include <linux/pagemap.h>
17
18#include <asm/uaccess.h>
19#include <asm/unistd.h>
20
21void generic_fillattr(struct inode *inode, struct kstat *stat)
22{
23 stat->dev = inode->i_sb->s_dev;
24 stat->ino = inode->i_ino;
25 stat->mode = inode->i_mode;
26 stat->nlink = inode->i_nlink;
27 stat->uid = inode->i_uid;
28 stat->gid = inode->i_gid;
29 stat->rdev = inode->i_rdev;
30 stat->size = i_size_read(inode);
31 stat->atime = inode->i_atime;
32 stat->mtime = inode->i_mtime;
33 stat->ctime = inode->i_ctime;
34 stat->blksize = (1 << inode->i_blkbits);
35 stat->blocks = inode->i_blocks;
36}
37
38EXPORT_SYMBOL(generic_fillattr);
39
40/**
41 * vfs_getattr_nosec - getattr without security checks
42 * @path: file to get attributes from
43 * @stat: structure to return attributes in
44 *
45 * Get attributes without calling security_inode_getattr.
46 *
47 * Currently the only caller other than vfs_getattr is internal to the
48 * filehandle lookup code, which uses only the inode number and returns
49 * no attributes to any user. Any other code probably wants
50 * vfs_getattr.
51 */
52int vfs_getattr_nosec(struct path *path, struct kstat *stat)
53{
54 struct inode *inode = d_backing_inode(path->dentry);
55
56 if (inode->i_op->getattr)
57 return inode->i_op->getattr(path->mnt, path->dentry, stat);
58
59 generic_fillattr(inode, stat);
60 return 0;
61}
62
63EXPORT_SYMBOL(vfs_getattr_nosec);
64
65int vfs_getattr(struct path *path, struct kstat *stat)
66{
67 int retval;
68
69 retval = security_inode_getattr(path);
70 if (retval)
71 return retval;
72 return vfs_getattr_nosec(path, stat);
73}
74
75EXPORT_SYMBOL(vfs_getattr);
76
77int vfs_fstat(unsigned int fd, struct kstat *stat)
78{
79 struct fd f = fdget_raw(fd);
80 int error = -EBADF;
81
82 if (f.file) {
83 error = vfs_getattr(&f.file->f_path, stat);
84 fdput(f);
85 }
86 return error;
87}
88EXPORT_SYMBOL(vfs_fstat);
89
90int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
91 int flag)
92{
93 struct path path;
94 int error = -EINVAL;
95 unsigned int lookup_flags = 0;
96
97 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
98 AT_EMPTY_PATH)) != 0)
99 goto out;
100
101 if (!(flag & AT_SYMLINK_NOFOLLOW))
102 lookup_flags |= LOOKUP_FOLLOW;
103 if (flag & AT_EMPTY_PATH)
104 lookup_flags |= LOOKUP_EMPTY;
105retry:
106 error = user_path_at(dfd, filename, lookup_flags, &path);
107 if (error)
108 goto out;
109
110 error = vfs_getattr(&path, stat);
111 path_put(&path);
112 if (retry_estale(error, lookup_flags)) {
113 lookup_flags |= LOOKUP_REVAL;
114 goto retry;
115 }
116out:
117 return error;
118}
119EXPORT_SYMBOL(vfs_fstatat);
120
121int vfs_stat(const char __user *name, struct kstat *stat)
122{
123 return vfs_fstatat(AT_FDCWD, name, stat, 0);
124}
125EXPORT_SYMBOL(vfs_stat);
126
127int vfs_lstat(const char __user *name, struct kstat *stat)
128{
129 return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
130}
131EXPORT_SYMBOL(vfs_lstat);
132
133
134#ifdef __ARCH_WANT_OLD_STAT
135
136/*
137 * For backward compatibility? Maybe this should be moved
138 * into arch/i386 instead?
139 */
140static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
141{
142 static int warncount = 5;
143 struct __old_kernel_stat tmp;
144
145 if (warncount > 0) {
146 warncount--;
147 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
148 current->comm);
149 } else if (warncount < 0) {
150 /* it's laughable, but... */
151 warncount = 0;
152 }
153
154 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
155 tmp.st_dev = old_encode_dev(stat->dev);
156 tmp.st_ino = stat->ino;
157 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
158 return -EOVERFLOW;
159 tmp.st_mode = stat->mode;
160 tmp.st_nlink = stat->nlink;
161 if (tmp.st_nlink != stat->nlink)
162 return -EOVERFLOW;
163 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
164 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
165 tmp.st_rdev = old_encode_dev(stat->rdev);
166#if BITS_PER_LONG == 32
167 if (stat->size > MAX_NON_LFS)
168 return -EOVERFLOW;
169#endif
170 tmp.st_size = stat->size;
171 tmp.st_atime = stat->atime.tv_sec;
172 tmp.st_mtime = stat->mtime.tv_sec;
173 tmp.st_ctime = stat->ctime.tv_sec;
174 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
175}
176
177SYSCALL_DEFINE2(stat, const char __user *, filename,
178 struct __old_kernel_stat __user *, statbuf)
179{
180 struct kstat stat;
181 int error;
182
183 error = vfs_stat(filename, &stat);
184 if (error)
185 return error;
186
187 return cp_old_stat(&stat, statbuf);
188}
189
190SYSCALL_DEFINE2(lstat, const char __user *, filename,
191 struct __old_kernel_stat __user *, statbuf)
192{
193 struct kstat stat;
194 int error;
195
196 error = vfs_lstat(filename, &stat);
197 if (error)
198 return error;
199
200 return cp_old_stat(&stat, statbuf);
201}
202
203SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
204{
205 struct kstat stat;
206 int error = vfs_fstat(fd, &stat);
207
208 if (!error)
209 error = cp_old_stat(&stat, statbuf);
210
211 return error;
212}
213
214#endif /* __ARCH_WANT_OLD_STAT */
215
216#if BITS_PER_LONG == 32
217# define choose_32_64(a,b) a
218#else
219# define choose_32_64(a,b) b
220#endif
221
222#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
223#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
224
225#ifndef INIT_STRUCT_STAT_PADDING
226# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
227#endif
228
229static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
230{
231 struct stat tmp;
232
233 if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
234 return -EOVERFLOW;
235#if BITS_PER_LONG == 32
236 if (stat->size > MAX_NON_LFS)
237 return -EOVERFLOW;
238#endif
239
240 INIT_STRUCT_STAT_PADDING(tmp);
241 tmp.st_dev = encode_dev(stat->dev);
242 tmp.st_ino = stat->ino;
243 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
244 return -EOVERFLOW;
245 tmp.st_mode = stat->mode;
246 tmp.st_nlink = stat->nlink;
247 if (tmp.st_nlink != stat->nlink)
248 return -EOVERFLOW;
249 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
250 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
251 tmp.st_rdev = encode_dev(stat->rdev);
252 tmp.st_size = stat->size;
253 tmp.st_atime = stat->atime.tv_sec;
254 tmp.st_mtime = stat->mtime.tv_sec;
255 tmp.st_ctime = stat->ctime.tv_sec;
256#ifdef STAT_HAVE_NSEC
257 tmp.st_atime_nsec = stat->atime.tv_nsec;
258 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
259 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
260#endif
261 tmp.st_blocks = stat->blocks;
262 tmp.st_blksize = stat->blksize;
263 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
264}
265
266SYSCALL_DEFINE2(newstat, const char __user *, filename,
267 struct stat __user *, statbuf)
268{
269 struct kstat stat;
270 int error = vfs_stat(filename, &stat);
271
272 if (error)
273 return error;
274 return cp_new_stat(&stat, statbuf);
275}
276
277SYSCALL_DEFINE2(newlstat, const char __user *, filename,
278 struct stat __user *, statbuf)
279{
280 struct kstat stat;
281 int error;
282
283 error = vfs_lstat(filename, &stat);
284 if (error)
285 return error;
286
287 return cp_new_stat(&stat, statbuf);
288}
289
290#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
291SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
292 struct stat __user *, statbuf, int, flag)
293{
294 struct kstat stat;
295 int error;
296
297 error = vfs_fstatat(dfd, filename, &stat, flag);
298 if (error)
299 return error;
300 return cp_new_stat(&stat, statbuf);
301}
302#endif
303
304SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
305{
306 struct kstat stat;
307 int error = vfs_fstat(fd, &stat);
308
309 if (!error)
310 error = cp_new_stat(&stat, statbuf);
311
312 return error;
313}
314
315SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
316 char __user *, buf, int, bufsiz)
317{
318 struct path path;
319 int error;
320 int empty = 0;
321 unsigned int lookup_flags = LOOKUP_EMPTY;
322
323 if (bufsiz <= 0)
324 return -EINVAL;
325
326retry:
327 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
328 if (!error) {
329 struct inode *inode = d_backing_inode(path.dentry);
330
331 error = empty ? -ENOENT : -EINVAL;
332 if (inode->i_op->readlink) {
333 error = security_inode_readlink(path.dentry);
334 if (!error) {
335 touch_atime(&path);
336 error = inode->i_op->readlink(path.dentry,
337 buf, bufsiz);
338 }
339 }
340 path_put(&path);
341 if (retry_estale(error, lookup_flags)) {
342 lookup_flags |= LOOKUP_REVAL;
343 goto retry;
344 }
345 }
346 return error;
347}
348
349SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
350 int, bufsiz)
351{
352 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
353}
354
355
356/* ---------- LFS-64 ----------- */
357#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
358
359#ifndef INIT_STRUCT_STAT64_PADDING
360# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
361#endif
362
363static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
364{
365 struct stat64 tmp;
366
367 INIT_STRUCT_STAT64_PADDING(tmp);
368#ifdef CONFIG_MIPS
369 /* mips has weird padding, so we don't get 64 bits there */
370 tmp.st_dev = new_encode_dev(stat->dev);
371 tmp.st_rdev = new_encode_dev(stat->rdev);
372#else
373 tmp.st_dev = huge_encode_dev(stat->dev);
374 tmp.st_rdev = huge_encode_dev(stat->rdev);
375#endif
376 tmp.st_ino = stat->ino;
377 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
378 return -EOVERFLOW;
379#ifdef STAT64_HAS_BROKEN_ST_INO
380 tmp.__st_ino = stat->ino;
381#endif
382 tmp.st_mode = stat->mode;
383 tmp.st_nlink = stat->nlink;
384 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
385 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
386 tmp.st_atime = stat->atime.tv_sec;
387 tmp.st_atime_nsec = stat->atime.tv_nsec;
388 tmp.st_mtime = stat->mtime.tv_sec;
389 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
390 tmp.st_ctime = stat->ctime.tv_sec;
391 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
392 tmp.st_size = stat->size;
393 tmp.st_blocks = stat->blocks;
394 tmp.st_blksize = stat->blksize;
395 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
396}
397
398SYSCALL_DEFINE2(stat64, const char __user *, filename,
399 struct stat64 __user *, statbuf)
400{
401 struct kstat stat;
402 int error = vfs_stat(filename, &stat);
403
404 if (!error)
405 error = cp_new_stat64(&stat, statbuf);
406
407 return error;
408}
409
410SYSCALL_DEFINE2(lstat64, const char __user *, filename,
411 struct stat64 __user *, statbuf)
412{
413 struct kstat stat;
414 int error = vfs_lstat(filename, &stat);
415
416 if (!error)
417 error = cp_new_stat64(&stat, statbuf);
418
419 return error;
420}
421
422SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
423{
424 struct kstat stat;
425 int error = vfs_fstat(fd, &stat);
426
427 if (!error)
428 error = cp_new_stat64(&stat, statbuf);
429
430 return error;
431}
432
433SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
434 struct stat64 __user *, statbuf, int, flag)
435{
436 struct kstat stat;
437 int error;
438
439 error = vfs_fstatat(dfd, filename, &stat, flag);
440 if (error)
441 return error;
442 return cp_new_stat64(&stat, statbuf);
443}
444#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
445
446/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
447void __inode_add_bytes(struct inode *inode, loff_t bytes)
448{
449 inode->i_blocks += bytes >> 9;
450 bytes &= 511;
451 inode->i_bytes += bytes;
452 if (inode->i_bytes >= 512) {
453 inode->i_blocks++;
454 inode->i_bytes -= 512;
455 }
456}
457
458void inode_add_bytes(struct inode *inode, loff_t bytes)
459{
460 spin_lock(&inode->i_lock);
461 __inode_add_bytes(inode, bytes);
462 spin_unlock(&inode->i_lock);
463}
464
465EXPORT_SYMBOL(inode_add_bytes);
466
467void __inode_sub_bytes(struct inode *inode, loff_t bytes)
468{
469 inode->i_blocks -= bytes >> 9;
470 bytes &= 511;
471 if (inode->i_bytes < bytes) {
472 inode->i_blocks--;
473 inode->i_bytes += 512;
474 }
475 inode->i_bytes -= bytes;
476}
477
478EXPORT_SYMBOL(__inode_sub_bytes);
479
480void inode_sub_bytes(struct inode *inode, loff_t bytes)
481{
482 spin_lock(&inode->i_lock);
483 __inode_sub_bytes(inode, bytes);
484 spin_unlock(&inode->i_lock);
485}
486
487EXPORT_SYMBOL(inode_sub_bytes);
488
489loff_t inode_get_bytes(struct inode *inode)
490{
491 loff_t ret;
492
493 spin_lock(&inode->i_lock);
494 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
495 spin_unlock(&inode->i_lock);
496 return ret;
497}
498
499EXPORT_SYMBOL(inode_get_bytes);
500
501void inode_set_bytes(struct inode *inode, loff_t bytes)
502{
503 /* Caller is here responsible for sufficient locking
504 * (ie. inode->i_lock) */
505 inode->i_blocks = bytes >> 9;
506 inode->i_bytes = bytes & 511;
507}
508
509EXPORT_SYMBOL(inode_set_bytes);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/export.h>
9#include <linux/mm.h>
10#include <linux/errno.h>
11#include <linux/file.h>
12#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
16#include <linux/cred.h>
17#include <linux/syscalls.h>
18#include <linux/pagemap.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22#include <asm/unistd.h>
23
24/**
25 * generic_fillattr - Fill in the basic attributes from the inode struct
26 * @inode: Inode to use as the source
27 * @stat: Where to fill in the attributes
28 *
29 * Fill in the basic attributes in the kstat structure from data that's to be
30 * found on the VFS inode structure. This is the default if no getattr inode
31 * operation is supplied.
32 */
33void generic_fillattr(struct inode *inode, struct kstat *stat)
34{
35 stat->dev = inode->i_sb->s_dev;
36 stat->ino = inode->i_ino;
37 stat->mode = inode->i_mode;
38 stat->nlink = inode->i_nlink;
39 stat->uid = inode->i_uid;
40 stat->gid = inode->i_gid;
41 stat->rdev = inode->i_rdev;
42 stat->size = i_size_read(inode);
43 stat->atime = inode->i_atime;
44 stat->mtime = inode->i_mtime;
45 stat->ctime = inode->i_ctime;
46 stat->blksize = i_blocksize(inode);
47 stat->blocks = inode->i_blocks;
48}
49EXPORT_SYMBOL(generic_fillattr);
50
51/**
52 * vfs_getattr_nosec - getattr without security checks
53 * @path: file to get attributes from
54 * @stat: structure to return attributes in
55 * @request_mask: STATX_xxx flags indicating what the caller wants
56 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
57 *
58 * Get attributes without calling security_inode_getattr.
59 *
60 * Currently the only caller other than vfs_getattr is internal to the
61 * filehandle lookup code, which uses only the inode number and returns no
62 * attributes to any user. Any other code probably wants vfs_getattr.
63 */
64int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
65 u32 request_mask, unsigned int query_flags)
66{
67 struct inode *inode = d_backing_inode(path->dentry);
68
69 memset(stat, 0, sizeof(*stat));
70 stat->result_mask |= STATX_BASIC_STATS;
71 request_mask &= STATX_ALL;
72 query_flags &= KSTAT_QUERY_FLAGS;
73
74 /* allow the fs to override these if it really wants to */
75 if (IS_NOATIME(inode))
76 stat->result_mask &= ~STATX_ATIME;
77 if (IS_AUTOMOUNT(inode))
78 stat->attributes |= STATX_ATTR_AUTOMOUNT;
79
80 if (inode->i_op->getattr)
81 return inode->i_op->getattr(path, stat, request_mask,
82 query_flags);
83
84 generic_fillattr(inode, stat);
85 return 0;
86}
87EXPORT_SYMBOL(vfs_getattr_nosec);
88
89/*
90 * vfs_getattr - Get the enhanced basic attributes of a file
91 * @path: The file of interest
92 * @stat: Where to return the statistics
93 * @request_mask: STATX_xxx flags indicating what the caller wants
94 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
95 *
96 * Ask the filesystem for a file's attributes. The caller must indicate in
97 * request_mask and query_flags to indicate what they want.
98 *
99 * If the file is remote, the filesystem can be forced to update the attributes
100 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
101 * suppress the update by passing AT_STATX_DONT_SYNC.
102 *
103 * Bits must have been set in request_mask to indicate which attributes the
104 * caller wants retrieving. Any such attribute not requested may be returned
105 * anyway, but the value may be approximate, and, if remote, may not have been
106 * synchronised with the server.
107 *
108 * 0 will be returned on success, and a -ve error code if unsuccessful.
109 */
110int vfs_getattr(const struct path *path, struct kstat *stat,
111 u32 request_mask, unsigned int query_flags)
112{
113 int retval;
114
115 retval = security_inode_getattr(path);
116 if (retval)
117 return retval;
118 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
119}
120EXPORT_SYMBOL(vfs_getattr);
121
122/**
123 * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
124 * @fd: The file descriptor referring to the file of interest
125 * @stat: The result structure to fill in.
126 * @request_mask: STATX_xxx flags indicating what the caller wants
127 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
128 *
129 * This function is a wrapper around vfs_getattr(). The main difference is
130 * that it uses a file descriptor to determine the file location.
131 *
132 * 0 will be returned on success, and a -ve error code if unsuccessful.
133 */
134int vfs_statx_fd(unsigned int fd, struct kstat *stat,
135 u32 request_mask, unsigned int query_flags)
136{
137 struct fd f;
138 int error = -EBADF;
139
140 if (query_flags & ~KSTAT_QUERY_FLAGS)
141 return -EINVAL;
142
143 f = fdget_raw(fd);
144 if (f.file) {
145 error = vfs_getattr(&f.file->f_path, stat,
146 request_mask, query_flags);
147 fdput(f);
148 }
149 return error;
150}
151EXPORT_SYMBOL(vfs_statx_fd);
152
153/**
154 * vfs_statx - Get basic and extra attributes by filename
155 * @dfd: A file descriptor representing the base dir for a relative filename
156 * @filename: The name of the file of interest
157 * @flags: Flags to control the query
158 * @stat: The result structure to fill in.
159 * @request_mask: STATX_xxx flags indicating what the caller wants
160 *
161 * This function is a wrapper around vfs_getattr(). The main difference is
162 * that it uses a filename and base directory to determine the file location.
163 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
164 * at the given name from being referenced.
165 *
166 * 0 will be returned on success, and a -ve error code if unsuccessful.
167 */
168int vfs_statx(int dfd, const char __user *filename, int flags,
169 struct kstat *stat, u32 request_mask)
170{
171 struct path path;
172 int error = -EINVAL;
173 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
174
175 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
176 AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
177 return -EINVAL;
178
179 if (flags & AT_SYMLINK_NOFOLLOW)
180 lookup_flags &= ~LOOKUP_FOLLOW;
181 if (flags & AT_NO_AUTOMOUNT)
182 lookup_flags &= ~LOOKUP_AUTOMOUNT;
183 if (flags & AT_EMPTY_PATH)
184 lookup_flags |= LOOKUP_EMPTY;
185
186retry:
187 error = user_path_at(dfd, filename, lookup_flags, &path);
188 if (error)
189 goto out;
190
191 error = vfs_getattr(&path, stat, request_mask, flags);
192 path_put(&path);
193 if (retry_estale(error, lookup_flags)) {
194 lookup_flags |= LOOKUP_REVAL;
195 goto retry;
196 }
197out:
198 return error;
199}
200EXPORT_SYMBOL(vfs_statx);
201
202
203#ifdef __ARCH_WANT_OLD_STAT
204
205/*
206 * For backward compatibility? Maybe this should be moved
207 * into arch/i386 instead?
208 */
209static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
210{
211 static int warncount = 5;
212 struct __old_kernel_stat tmp;
213
214 if (warncount > 0) {
215 warncount--;
216 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
217 current->comm);
218 } else if (warncount < 0) {
219 /* it's laughable, but... */
220 warncount = 0;
221 }
222
223 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
224 tmp.st_dev = old_encode_dev(stat->dev);
225 tmp.st_ino = stat->ino;
226 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
227 return -EOVERFLOW;
228 tmp.st_mode = stat->mode;
229 tmp.st_nlink = stat->nlink;
230 if (tmp.st_nlink != stat->nlink)
231 return -EOVERFLOW;
232 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
233 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
234 tmp.st_rdev = old_encode_dev(stat->rdev);
235#if BITS_PER_LONG == 32
236 if (stat->size > MAX_NON_LFS)
237 return -EOVERFLOW;
238#endif
239 tmp.st_size = stat->size;
240 tmp.st_atime = stat->atime.tv_sec;
241 tmp.st_mtime = stat->mtime.tv_sec;
242 tmp.st_ctime = stat->ctime.tv_sec;
243 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
244}
245
246SYSCALL_DEFINE2(stat, const char __user *, filename,
247 struct __old_kernel_stat __user *, statbuf)
248{
249 struct kstat stat;
250 int error;
251
252 error = vfs_stat(filename, &stat);
253 if (error)
254 return error;
255
256 return cp_old_stat(&stat, statbuf);
257}
258
259SYSCALL_DEFINE2(lstat, const char __user *, filename,
260 struct __old_kernel_stat __user *, statbuf)
261{
262 struct kstat stat;
263 int error;
264
265 error = vfs_lstat(filename, &stat);
266 if (error)
267 return error;
268
269 return cp_old_stat(&stat, statbuf);
270}
271
272SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
273{
274 struct kstat stat;
275 int error = vfs_fstat(fd, &stat);
276
277 if (!error)
278 error = cp_old_stat(&stat, statbuf);
279
280 return error;
281}
282
283#endif /* __ARCH_WANT_OLD_STAT */
284
285#ifdef __ARCH_WANT_NEW_STAT
286
287#if BITS_PER_LONG == 32
288# define choose_32_64(a,b) a
289#else
290# define choose_32_64(a,b) b
291#endif
292
293#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
294#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
295
296#ifndef INIT_STRUCT_STAT_PADDING
297# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
298#endif
299
300static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
301{
302 struct stat tmp;
303
304 if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
305 return -EOVERFLOW;
306#if BITS_PER_LONG == 32
307 if (stat->size > MAX_NON_LFS)
308 return -EOVERFLOW;
309#endif
310
311 INIT_STRUCT_STAT_PADDING(tmp);
312 tmp.st_dev = encode_dev(stat->dev);
313 tmp.st_ino = stat->ino;
314 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
315 return -EOVERFLOW;
316 tmp.st_mode = stat->mode;
317 tmp.st_nlink = stat->nlink;
318 if (tmp.st_nlink != stat->nlink)
319 return -EOVERFLOW;
320 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
321 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
322 tmp.st_rdev = encode_dev(stat->rdev);
323 tmp.st_size = stat->size;
324 tmp.st_atime = stat->atime.tv_sec;
325 tmp.st_mtime = stat->mtime.tv_sec;
326 tmp.st_ctime = stat->ctime.tv_sec;
327#ifdef STAT_HAVE_NSEC
328 tmp.st_atime_nsec = stat->atime.tv_nsec;
329 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
330 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
331#endif
332 tmp.st_blocks = stat->blocks;
333 tmp.st_blksize = stat->blksize;
334 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
335}
336
337SYSCALL_DEFINE2(newstat, const char __user *, filename,
338 struct stat __user *, statbuf)
339{
340 struct kstat stat;
341 int error = vfs_stat(filename, &stat);
342
343 if (error)
344 return error;
345 return cp_new_stat(&stat, statbuf);
346}
347
348SYSCALL_DEFINE2(newlstat, const char __user *, filename,
349 struct stat __user *, statbuf)
350{
351 struct kstat stat;
352 int error;
353
354 error = vfs_lstat(filename, &stat);
355 if (error)
356 return error;
357
358 return cp_new_stat(&stat, statbuf);
359}
360
361#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
362SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
363 struct stat __user *, statbuf, int, flag)
364{
365 struct kstat stat;
366 int error;
367
368 error = vfs_fstatat(dfd, filename, &stat, flag);
369 if (error)
370 return error;
371 return cp_new_stat(&stat, statbuf);
372}
373#endif
374
375SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
376{
377 struct kstat stat;
378 int error = vfs_fstat(fd, &stat);
379
380 if (!error)
381 error = cp_new_stat(&stat, statbuf);
382
383 return error;
384}
385#endif
386
387static int do_readlinkat(int dfd, const char __user *pathname,
388 char __user *buf, int bufsiz)
389{
390 struct path path;
391 int error;
392 int empty = 0;
393 unsigned int lookup_flags = LOOKUP_EMPTY;
394
395 if (bufsiz <= 0)
396 return -EINVAL;
397
398retry:
399 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
400 if (!error) {
401 struct inode *inode = d_backing_inode(path.dentry);
402
403 error = empty ? -ENOENT : -EINVAL;
404 /*
405 * AFS mountpoints allow readlink(2) but are not symlinks
406 */
407 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
408 error = security_inode_readlink(path.dentry);
409 if (!error) {
410 touch_atime(&path);
411 error = vfs_readlink(path.dentry, buf, bufsiz);
412 }
413 }
414 path_put(&path);
415 if (retry_estale(error, lookup_flags)) {
416 lookup_flags |= LOOKUP_REVAL;
417 goto retry;
418 }
419 }
420 return error;
421}
422
423SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
424 char __user *, buf, int, bufsiz)
425{
426 return do_readlinkat(dfd, pathname, buf, bufsiz);
427}
428
429SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
430 int, bufsiz)
431{
432 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
433}
434
435
436/* ---------- LFS-64 ----------- */
437#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
438
439#ifndef INIT_STRUCT_STAT64_PADDING
440# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
441#endif
442
443static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
444{
445 struct stat64 tmp;
446
447 INIT_STRUCT_STAT64_PADDING(tmp);
448#ifdef CONFIG_MIPS
449 /* mips has weird padding, so we don't get 64 bits there */
450 tmp.st_dev = new_encode_dev(stat->dev);
451 tmp.st_rdev = new_encode_dev(stat->rdev);
452#else
453 tmp.st_dev = huge_encode_dev(stat->dev);
454 tmp.st_rdev = huge_encode_dev(stat->rdev);
455#endif
456 tmp.st_ino = stat->ino;
457 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
458 return -EOVERFLOW;
459#ifdef STAT64_HAS_BROKEN_ST_INO
460 tmp.__st_ino = stat->ino;
461#endif
462 tmp.st_mode = stat->mode;
463 tmp.st_nlink = stat->nlink;
464 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
465 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
466 tmp.st_atime = stat->atime.tv_sec;
467 tmp.st_atime_nsec = stat->atime.tv_nsec;
468 tmp.st_mtime = stat->mtime.tv_sec;
469 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
470 tmp.st_ctime = stat->ctime.tv_sec;
471 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
472 tmp.st_size = stat->size;
473 tmp.st_blocks = stat->blocks;
474 tmp.st_blksize = stat->blksize;
475 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
476}
477
478SYSCALL_DEFINE2(stat64, const char __user *, filename,
479 struct stat64 __user *, statbuf)
480{
481 struct kstat stat;
482 int error = vfs_stat(filename, &stat);
483
484 if (!error)
485 error = cp_new_stat64(&stat, statbuf);
486
487 return error;
488}
489
490SYSCALL_DEFINE2(lstat64, const char __user *, filename,
491 struct stat64 __user *, statbuf)
492{
493 struct kstat stat;
494 int error = vfs_lstat(filename, &stat);
495
496 if (!error)
497 error = cp_new_stat64(&stat, statbuf);
498
499 return error;
500}
501
502SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
503{
504 struct kstat stat;
505 int error = vfs_fstat(fd, &stat);
506
507 if (!error)
508 error = cp_new_stat64(&stat, statbuf);
509
510 return error;
511}
512
513SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
514 struct stat64 __user *, statbuf, int, flag)
515{
516 struct kstat stat;
517 int error;
518
519 error = vfs_fstatat(dfd, filename, &stat, flag);
520 if (error)
521 return error;
522 return cp_new_stat64(&stat, statbuf);
523}
524#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
525
526static noinline_for_stack int
527cp_statx(const struct kstat *stat, struct statx __user *buffer)
528{
529 struct statx tmp;
530
531 memset(&tmp, 0, sizeof(tmp));
532
533 tmp.stx_mask = stat->result_mask;
534 tmp.stx_blksize = stat->blksize;
535 tmp.stx_attributes = stat->attributes;
536 tmp.stx_nlink = stat->nlink;
537 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
538 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
539 tmp.stx_mode = stat->mode;
540 tmp.stx_ino = stat->ino;
541 tmp.stx_size = stat->size;
542 tmp.stx_blocks = stat->blocks;
543 tmp.stx_attributes_mask = stat->attributes_mask;
544 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
545 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
546 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
547 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
548 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
549 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
550 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
551 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
552 tmp.stx_rdev_major = MAJOR(stat->rdev);
553 tmp.stx_rdev_minor = MINOR(stat->rdev);
554 tmp.stx_dev_major = MAJOR(stat->dev);
555 tmp.stx_dev_minor = MINOR(stat->dev);
556
557 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
558}
559
560/**
561 * sys_statx - System call to get enhanced stats
562 * @dfd: Base directory to pathwalk from *or* fd to stat.
563 * @filename: File to stat or "" with AT_EMPTY_PATH
564 * @flags: AT_* flags to control pathwalk.
565 * @mask: Parts of statx struct actually required.
566 * @buffer: Result buffer.
567 *
568 * Note that fstat() can be emulated by setting dfd to the fd of interest,
569 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
570 */
571SYSCALL_DEFINE5(statx,
572 int, dfd, const char __user *, filename, unsigned, flags,
573 unsigned int, mask,
574 struct statx __user *, buffer)
575{
576 struct kstat stat;
577 int error;
578
579 if (mask & STATX__RESERVED)
580 return -EINVAL;
581 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
582 return -EINVAL;
583
584 error = vfs_statx(dfd, filename, flags, &stat, mask);
585 if (error)
586 return error;
587
588 return cp_statx(&stat, buffer);
589}
590
591#ifdef CONFIG_COMPAT
592static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
593{
594 struct compat_stat tmp;
595
596 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
597 return -EOVERFLOW;
598
599 memset(&tmp, 0, sizeof(tmp));
600 tmp.st_dev = old_encode_dev(stat->dev);
601 tmp.st_ino = stat->ino;
602 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
603 return -EOVERFLOW;
604 tmp.st_mode = stat->mode;
605 tmp.st_nlink = stat->nlink;
606 if (tmp.st_nlink != stat->nlink)
607 return -EOVERFLOW;
608 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
609 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
610 tmp.st_rdev = old_encode_dev(stat->rdev);
611 if ((u64) stat->size > MAX_NON_LFS)
612 return -EOVERFLOW;
613 tmp.st_size = stat->size;
614 tmp.st_atime = stat->atime.tv_sec;
615 tmp.st_atime_nsec = stat->atime.tv_nsec;
616 tmp.st_mtime = stat->mtime.tv_sec;
617 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
618 tmp.st_ctime = stat->ctime.tv_sec;
619 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
620 tmp.st_blocks = stat->blocks;
621 tmp.st_blksize = stat->blksize;
622 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
623}
624
625COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
626 struct compat_stat __user *, statbuf)
627{
628 struct kstat stat;
629 int error;
630
631 error = vfs_stat(filename, &stat);
632 if (error)
633 return error;
634 return cp_compat_stat(&stat, statbuf);
635}
636
637COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
638 struct compat_stat __user *, statbuf)
639{
640 struct kstat stat;
641 int error;
642
643 error = vfs_lstat(filename, &stat);
644 if (error)
645 return error;
646 return cp_compat_stat(&stat, statbuf);
647}
648
649#ifndef __ARCH_WANT_STAT64
650COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
651 const char __user *, filename,
652 struct compat_stat __user *, statbuf, int, flag)
653{
654 struct kstat stat;
655 int error;
656
657 error = vfs_fstatat(dfd, filename, &stat, flag);
658 if (error)
659 return error;
660 return cp_compat_stat(&stat, statbuf);
661}
662#endif
663
664COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
665 struct compat_stat __user *, statbuf)
666{
667 struct kstat stat;
668 int error = vfs_fstat(fd, &stat);
669
670 if (!error)
671 error = cp_compat_stat(&stat, statbuf);
672 return error;
673}
674#endif
675
676/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
677void __inode_add_bytes(struct inode *inode, loff_t bytes)
678{
679 inode->i_blocks += bytes >> 9;
680 bytes &= 511;
681 inode->i_bytes += bytes;
682 if (inode->i_bytes >= 512) {
683 inode->i_blocks++;
684 inode->i_bytes -= 512;
685 }
686}
687EXPORT_SYMBOL(__inode_add_bytes);
688
689void inode_add_bytes(struct inode *inode, loff_t bytes)
690{
691 spin_lock(&inode->i_lock);
692 __inode_add_bytes(inode, bytes);
693 spin_unlock(&inode->i_lock);
694}
695
696EXPORT_SYMBOL(inode_add_bytes);
697
698void __inode_sub_bytes(struct inode *inode, loff_t bytes)
699{
700 inode->i_blocks -= bytes >> 9;
701 bytes &= 511;
702 if (inode->i_bytes < bytes) {
703 inode->i_blocks--;
704 inode->i_bytes += 512;
705 }
706 inode->i_bytes -= bytes;
707}
708
709EXPORT_SYMBOL(__inode_sub_bytes);
710
711void inode_sub_bytes(struct inode *inode, loff_t bytes)
712{
713 spin_lock(&inode->i_lock);
714 __inode_sub_bytes(inode, bytes);
715 spin_unlock(&inode->i_lock);
716}
717
718EXPORT_SYMBOL(inode_sub_bytes);
719
720loff_t inode_get_bytes(struct inode *inode)
721{
722 loff_t ret;
723
724 spin_lock(&inode->i_lock);
725 ret = __inode_get_bytes(inode);
726 spin_unlock(&inode->i_lock);
727 return ret;
728}
729
730EXPORT_SYMBOL(inode_get_bytes);
731
732void inode_set_bytes(struct inode *inode, loff_t bytes)
733{
734 /* Caller is here responsible for sufficient locking
735 * (ie. inode->i_lock) */
736 inode->i_blocks = bytes >> 9;
737 inode->i_bytes = bytes & 511;
738}
739
740EXPORT_SYMBOL(inode_set_bytes);