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v4.6
 
  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);
v6.13.7
  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/blkdev.h>
  9#include <linux/export.h>
 10#include <linux/mm.h>
 11#include <linux/errno.h>
 12#include <linux/file.h>
 13#include <linux/highuid.h>
 14#include <linux/fs.h>
 15#include <linux/namei.h>
 16#include <linux/security.h>
 17#include <linux/cred.h>
 18#include <linux/syscalls.h>
 19#include <linux/pagemap.h>
 20#include <linux/compat.h>
 21#include <linux/iversion.h>
 22
 23#include <linux/uaccess.h>
 24#include <asm/unistd.h>
 25
 26#include <trace/events/timestamp.h>
 27
 28#include "internal.h"
 29#include "mount.h"
 30
 31/**
 32 * fill_mg_cmtime - Fill in the mtime and ctime and flag ctime as QUERIED
 33 * @stat: where to store the resulting values
 34 * @request_mask: STATX_* values requested
 35 * @inode: inode from which to grab the c/mtime
 36 *
 37 * Given @inode, grab the ctime and mtime out if it and store the result
 38 * in @stat. When fetching the value, flag it as QUERIED (if not already)
 39 * so the next write will record a distinct timestamp.
 40 *
 41 * NB: The QUERIED flag is tracked in the ctime, but we set it there even
 42 * if only the mtime was requested, as that ensures that the next mtime
 43 * change will be distinct.
 44 */
 45void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode)
 46{
 47	atomic_t *pcn = (atomic_t *)&inode->i_ctime_nsec;
 48
 49	/* If neither time was requested, then don't report them */
 50	if (!(request_mask & (STATX_CTIME|STATX_MTIME))) {
 51		stat->result_mask &= ~(STATX_CTIME|STATX_MTIME);
 52		return;
 53	}
 54
 55	stat->mtime = inode_get_mtime(inode);
 56	stat->ctime.tv_sec = inode->i_ctime_sec;
 57	stat->ctime.tv_nsec = (u32)atomic_read(pcn);
 58	if (!(stat->ctime.tv_nsec & I_CTIME_QUERIED))
 59		stat->ctime.tv_nsec = ((u32)atomic_fetch_or(I_CTIME_QUERIED, pcn));
 60	stat->ctime.tv_nsec &= ~I_CTIME_QUERIED;
 61	trace_fill_mg_cmtime(inode, &stat->ctime, &stat->mtime);
 62}
 63EXPORT_SYMBOL(fill_mg_cmtime);
 64
 65/**
 66 * generic_fillattr - Fill in the basic attributes from the inode struct
 67 * @idmap:		idmap of the mount the inode was found from
 68 * @request_mask:	statx request_mask
 69 * @inode:		Inode to use as the source
 70 * @stat:		Where to fill in the attributes
 71 *
 72 * Fill in the basic attributes in the kstat structure from data that's to be
 73 * found on the VFS inode structure.  This is the default if no getattr inode
 74 * operation is supplied.
 75 *
 76 * If the inode has been found through an idmapped mount the idmap of
 77 * the vfsmount must be passed through @idmap. This function will then
 78 * take care to map the inode according to @idmap before filling in the
 79 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
 80 * performed on the raw inode simply pass @nop_mnt_idmap.
 81 */
 82void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
 83		      struct inode *inode, struct kstat *stat)
 84{
 85	vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
 86	vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
 87
 88	stat->dev = inode->i_sb->s_dev;
 89	stat->ino = inode->i_ino;
 90	stat->mode = inode->i_mode;
 91	stat->nlink = inode->i_nlink;
 92	stat->uid = vfsuid_into_kuid(vfsuid);
 93	stat->gid = vfsgid_into_kgid(vfsgid);
 94	stat->rdev = inode->i_rdev;
 95	stat->size = i_size_read(inode);
 96	stat->atime = inode_get_atime(inode);
 97
 98	if (is_mgtime(inode)) {
 99		fill_mg_cmtime(stat, request_mask, inode);
100	} else {
101		stat->ctime = inode_get_ctime(inode);
102		stat->mtime = inode_get_mtime(inode);
103	}
104
105	stat->blksize = i_blocksize(inode);
106	stat->blocks = inode->i_blocks;
 
107
108	if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
109		stat->result_mask |= STATX_CHANGE_COOKIE;
110		stat->change_cookie = inode_query_iversion(inode);
111	}
112
113}
114EXPORT_SYMBOL(generic_fillattr);
115
116/**
117 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
118 * @inode:	Inode to use as the source
119 * @stat:	Where to fill in the attribute flags
120 *
121 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
122 * inode that are published on i_flags and enforced by the VFS.
123 */
124void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
125{
126	if (inode->i_flags & S_IMMUTABLE)
127		stat->attributes |= STATX_ATTR_IMMUTABLE;
128	if (inode->i_flags & S_APPEND)
129		stat->attributes |= STATX_ATTR_APPEND;
130	stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
131}
132EXPORT_SYMBOL(generic_fill_statx_attr);
133
134/**
135 * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes
136 * @stat:	Where to fill in the attribute flags
137 * @unit_min:	Minimum supported atomic write length in bytes
138 * @unit_max:	Maximum supported atomic write length in bytes
139 *
140 * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from
141 * atomic write unit_min and unit_max values.
142 */
143void generic_fill_statx_atomic_writes(struct kstat *stat,
144				      unsigned int unit_min,
145				      unsigned int unit_max)
146{
147	/* Confirm that the request type is known */
148	stat->result_mask |= STATX_WRITE_ATOMIC;
149
150	/* Confirm that the file attribute type is known */
151	stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;
152
153	if (unit_min) {
154		stat->atomic_write_unit_min = unit_min;
155		stat->atomic_write_unit_max = unit_max;
156		/* Initially only allow 1x segment */
157		stat->atomic_write_segments_max = 1;
158
159		/* Confirm atomic writes are actually supported */
160		stat->attributes |= STATX_ATTR_WRITE_ATOMIC;
161	}
162}
163EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);
164
165/**
166 * vfs_getattr_nosec - getattr without security checks
167 * @path: file to get attributes from
168 * @stat: structure to return attributes in
169 * @request_mask: STATX_xxx flags indicating what the caller wants
170 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
171 *
172 * Get attributes without calling security_inode_getattr.
173 *
174 * Currently the only caller other than vfs_getattr is internal to the
175 * filehandle lookup code, which uses only the inode number and returns no
176 * attributes to any user.  Any other code probably wants vfs_getattr.
 
177 */
178int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
179		      u32 request_mask, unsigned int query_flags)
180{
181	struct mnt_idmap *idmap;
182	struct inode *inode = d_backing_inode(path->dentry);
183
184	memset(stat, 0, sizeof(*stat));
185	stat->result_mask |= STATX_BASIC_STATS;
186	query_flags &= AT_STATX_SYNC_TYPE;
187
188	/* allow the fs to override these if it really wants to */
189	/* SB_NOATIME means filesystem supplies dummy atime value */
190	if (inode->i_sb->s_flags & SB_NOATIME)
191		stat->result_mask &= ~STATX_ATIME;
192
193	/*
194	 * Note: If you add another clause to set an attribute flag, please
195	 * update attributes_mask below.
196	 */
197	if (IS_AUTOMOUNT(inode))
198		stat->attributes |= STATX_ATTR_AUTOMOUNT;
199
200	if (IS_DAX(inode))
201		stat->attributes |= STATX_ATTR_DAX;
202
203	stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
204				  STATX_ATTR_DAX);
205
206	idmap = mnt_idmap(path->mnt);
207	if (inode->i_op->getattr)
208		return inode->i_op->getattr(idmap, path, stat,
209					    request_mask,
210					    query_flags);
211
212	generic_fillattr(idmap, request_mask, inode, stat);
213	return 0;
214}
 
215EXPORT_SYMBOL(vfs_getattr_nosec);
216
217/*
218 * vfs_getattr - Get the enhanced basic attributes of a file
219 * @path: The file of interest
220 * @stat: Where to return the statistics
221 * @request_mask: STATX_xxx flags indicating what the caller wants
222 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
223 *
224 * Ask the filesystem for a file's attributes.  The caller must indicate in
225 * request_mask and query_flags to indicate what they want.
226 *
227 * If the file is remote, the filesystem can be forced to update the attributes
228 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
229 * suppress the update by passing AT_STATX_DONT_SYNC.
230 *
231 * Bits must have been set in request_mask to indicate which attributes the
232 * caller wants retrieving.  Any such attribute not requested may be returned
233 * anyway, but the value may be approximate, and, if remote, may not have been
234 * synchronised with the server.
235 *
236 * 0 will be returned on success, and a -ve error code if unsuccessful.
237 */
238int vfs_getattr(const struct path *path, struct kstat *stat,
239		u32 request_mask, unsigned int query_flags)
240{
241	int retval;
242
243	retval = security_inode_getattr(path);
244	if (retval)
245		return retval;
246	return vfs_getattr_nosec(path, stat, request_mask, query_flags);
247}
 
248EXPORT_SYMBOL(vfs_getattr);
249
250/**
251 * vfs_fstat - Get the basic attributes by file descriptor
252 * @fd: The file descriptor referring to the file of interest
253 * @stat: The result structure to fill in.
254 *
255 * This function is a wrapper around vfs_getattr().  The main difference is
256 * that it uses a file descriptor to determine the file location.
257 *
258 * 0 will be returned on success, and a -ve error code if unsuccessful.
259 */
260int vfs_fstat(int fd, struct kstat *stat)
261{
262	CLASS(fd_raw, f)(fd);
263	if (fd_empty(f))
264		return -EBADF;
265	return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
266}
267
268static int statx_lookup_flags(int flags)
269{
270	int lookup_flags = 0;
271
272	if (!(flags & AT_SYMLINK_NOFOLLOW))
273		lookup_flags |= LOOKUP_FOLLOW;
274	if (!(flags & AT_NO_AUTOMOUNT))
275		lookup_flags |= LOOKUP_AUTOMOUNT;
276
277	return lookup_flags;
278}
279
280static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
281			  u32 request_mask)
282{
283	int error = vfs_getattr(path, stat, request_mask, flags);
 
284
285	if (request_mask & STATX_MNT_ID_UNIQUE) {
286		stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
287		stat->result_mask |= STATX_MNT_ID_UNIQUE;
288	} else {
289		stat->mnt_id = real_mount(path->mnt)->mnt_id;
290		stat->result_mask |= STATX_MNT_ID;
291	}
292
293	if (path_mounted(path))
294		stat->attributes |= STATX_ATTR_MOUNT_ROOT;
295	stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
296
297	/*
298	 * If this is a block device inode, override the filesystem
299	 * attributes with the block device specific parameters that need to be
300	 * obtained from the bdev backing inode.
301	 */
302	if (S_ISBLK(stat->mode))
303		bdev_statx(path, stat, request_mask);
304
305	return error;
306}
 
307
308static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
309			  u32 request_mask)
310{
311	CLASS(fd_raw, f)(fd);
312	if (fd_empty(f))
313		return -EBADF;
314	return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);
315}
316
317/**
318 * vfs_statx - Get basic and extra attributes by filename
319 * @dfd: A file descriptor representing the base dir for a relative filename
320 * @filename: The name of the file of interest
321 * @flags: Flags to control the query
322 * @stat: The result structure to fill in.
323 * @request_mask: STATX_xxx flags indicating what the caller wants
324 *
325 * This function is a wrapper around vfs_getattr().  The main difference is
326 * that it uses a filename and base directory to determine the file location.
327 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
328 * at the given name from being referenced.
329 *
330 * 0 will be returned on success, and a -ve error code if unsuccessful.
331 */
332static int vfs_statx(int dfd, struct filename *filename, int flags,
333	      struct kstat *stat, u32 request_mask)
334{
335	struct path path;
336	unsigned int lookup_flags = statx_lookup_flags(flags);
337	int error;
338
339	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
340		      AT_STATX_SYNC_TYPE))
341		return -EINVAL;
342
 
 
 
 
343retry:
344	error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
345	if (error)
346		return error;
347	error = vfs_statx_path(&path, flags, stat, request_mask);
 
348	path_put(&path);
349	if (retry_estale(error, lookup_flags)) {
350		lookup_flags |= LOOKUP_REVAL;
351		goto retry;
352	}
 
353	return error;
354}
 
355
356int vfs_fstatat(int dfd, const char __user *filename,
357			      struct kstat *stat, int flags)
358{
359	int ret;
360	int statx_flags = flags | AT_NO_AUTOMOUNT;
361	struct filename *name = getname_maybe_null(filename, flags);
362
363	if (!name && dfd >= 0)
364		return vfs_fstat(dfd, stat);
365
366	ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
367	putname(name);
368
369	return ret;
370}
371
372#ifdef __ARCH_WANT_OLD_STAT
373
374/*
375 * For backward compatibility?  Maybe this should be moved
376 * into arch/i386 instead?
377 */
378static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
379{
380	static int warncount = 5;
381	struct __old_kernel_stat tmp;
382
383	if (warncount > 0) {
384		warncount--;
385		printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
386			current->comm);
387	} else if (warncount < 0) {
388		/* it's laughable, but... */
389		warncount = 0;
390	}
391
392	memset(&tmp, 0, sizeof(struct __old_kernel_stat));
393	tmp.st_dev = old_encode_dev(stat->dev);
394	tmp.st_ino = stat->ino;
395	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
396		return -EOVERFLOW;
397	tmp.st_mode = stat->mode;
398	tmp.st_nlink = stat->nlink;
399	if (tmp.st_nlink != stat->nlink)
400		return -EOVERFLOW;
401	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
402	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
403	tmp.st_rdev = old_encode_dev(stat->rdev);
404#if BITS_PER_LONG == 32
405	if (stat->size > MAX_NON_LFS)
406		return -EOVERFLOW;
407#endif
408	tmp.st_size = stat->size;
409	tmp.st_atime = stat->atime.tv_sec;
410	tmp.st_mtime = stat->mtime.tv_sec;
411	tmp.st_ctime = stat->ctime.tv_sec;
412	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
413}
414
415SYSCALL_DEFINE2(stat, const char __user *, filename,
416		struct __old_kernel_stat __user *, statbuf)
417{
418	struct kstat stat;
419	int error;
420
421	error = vfs_stat(filename, &stat);
422	if (error)
423		return error;
424
425	return cp_old_stat(&stat, statbuf);
426}
427
428SYSCALL_DEFINE2(lstat, const char __user *, filename,
429		struct __old_kernel_stat __user *, statbuf)
430{
431	struct kstat stat;
432	int error;
433
434	error = vfs_lstat(filename, &stat);
435	if (error)
436		return error;
437
438	return cp_old_stat(&stat, statbuf);
439}
440
441SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
442{
443	struct kstat stat;
444	int error = vfs_fstat(fd, &stat);
445
446	if (!error)
447		error = cp_old_stat(&stat, statbuf);
448
449	return error;
450}
451
452#endif /* __ARCH_WANT_OLD_STAT */
453
454#ifdef __ARCH_WANT_NEW_STAT
 
 
 
 
 
 
 
455
456#ifndef INIT_STRUCT_STAT_PADDING
457#  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
458#endif
459
460static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
461{
462	struct stat tmp;
463
464	if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
465		return -EOVERFLOW;
466	if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
467		return -EOVERFLOW;
468#if BITS_PER_LONG == 32
469	if (stat->size > MAX_NON_LFS)
470		return -EOVERFLOW;
471#endif
472
473	INIT_STRUCT_STAT_PADDING(tmp);
474	tmp.st_dev = new_encode_dev(stat->dev);
475	tmp.st_ino = stat->ino;
476	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
477		return -EOVERFLOW;
478	tmp.st_mode = stat->mode;
479	tmp.st_nlink = stat->nlink;
480	if (tmp.st_nlink != stat->nlink)
481		return -EOVERFLOW;
482	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
483	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
484	tmp.st_rdev = new_encode_dev(stat->rdev);
485	tmp.st_size = stat->size;
486	tmp.st_atime = stat->atime.tv_sec;
487	tmp.st_mtime = stat->mtime.tv_sec;
488	tmp.st_ctime = stat->ctime.tv_sec;
489#ifdef STAT_HAVE_NSEC
490	tmp.st_atime_nsec = stat->atime.tv_nsec;
491	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
492	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
493#endif
494	tmp.st_blocks = stat->blocks;
495	tmp.st_blksize = stat->blksize;
496	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
497}
498
499SYSCALL_DEFINE2(newstat, const char __user *, filename,
500		struct stat __user *, statbuf)
501{
502	struct kstat stat;
503	int error = vfs_stat(filename, &stat);
504
505	if (error)
506		return error;
507	return cp_new_stat(&stat, statbuf);
508}
509
510SYSCALL_DEFINE2(newlstat, const char __user *, filename,
511		struct stat __user *, statbuf)
512{
513	struct kstat stat;
514	int error;
515
516	error = vfs_lstat(filename, &stat);
517	if (error)
518		return error;
519
520	return cp_new_stat(&stat, statbuf);
521}
522
523#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
524SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
525		struct stat __user *, statbuf, int, flag)
526{
527	struct kstat stat;
528	int error;
529
530	error = vfs_fstatat(dfd, filename, &stat, flag);
531	if (error)
532		return error;
533	return cp_new_stat(&stat, statbuf);
534}
535#endif
536
537SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
538{
539	struct kstat stat;
540	int error = vfs_fstat(fd, &stat);
541
542	if (!error)
543		error = cp_new_stat(&stat, statbuf);
544
545	return error;
546}
547#endif
548
549static int do_readlinkat(int dfd, const char __user *pathname,
550			 char __user *buf, int bufsiz)
551{
552	struct path path;
553	struct filename *name;
554	int error;
 
555	unsigned int lookup_flags = LOOKUP_EMPTY;
556
557	if (bufsiz <= 0)
558		return -EINVAL;
559
560retry:
561	name = getname_flags(pathname, lookup_flags);
562	error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
563	if (unlikely(error)) {
564		putname(name);
565		return error;
566	}
567
568	/*
569	 * AFS mountpoints allow readlink(2) but are not symlinks
570	 */
571	if (d_is_symlink(path.dentry) ||
572	    d_backing_inode(path.dentry)->i_op->readlink) {
573		error = security_inode_readlink(path.dentry);
574		if (!error) {
575			touch_atime(&path);
576			error = vfs_readlink(path.dentry, buf, bufsiz);
 
577		}
578	} else {
579		error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;
580	}
581	path_put(&path);
582	putname(name);
583	if (retry_estale(error, lookup_flags)) {
584		lookup_flags |= LOOKUP_REVAL;
585		goto retry;
586	}
587	return error;
588}
589
590SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
591		char __user *, buf, int, bufsiz)
592{
593	return do_readlinkat(dfd, pathname, buf, bufsiz);
594}
595
596SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
597		int, bufsiz)
598{
599	return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
600}
601
602
603/* ---------- LFS-64 ----------- */
604#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
605
606#ifndef INIT_STRUCT_STAT64_PADDING
607#  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
608#endif
609
610static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
611{
612	struct stat64 tmp;
613
614	INIT_STRUCT_STAT64_PADDING(tmp);
615#ifdef CONFIG_MIPS
616	/* mips has weird padding, so we don't get 64 bits there */
617	tmp.st_dev = new_encode_dev(stat->dev);
618	tmp.st_rdev = new_encode_dev(stat->rdev);
619#else
620	tmp.st_dev = huge_encode_dev(stat->dev);
621	tmp.st_rdev = huge_encode_dev(stat->rdev);
622#endif
623	tmp.st_ino = stat->ino;
624	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
625		return -EOVERFLOW;
626#ifdef STAT64_HAS_BROKEN_ST_INO
627	tmp.__st_ino = stat->ino;
628#endif
629	tmp.st_mode = stat->mode;
630	tmp.st_nlink = stat->nlink;
631	tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
632	tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
633	tmp.st_atime = stat->atime.tv_sec;
634	tmp.st_atime_nsec = stat->atime.tv_nsec;
635	tmp.st_mtime = stat->mtime.tv_sec;
636	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
637	tmp.st_ctime = stat->ctime.tv_sec;
638	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
639	tmp.st_size = stat->size;
640	tmp.st_blocks = stat->blocks;
641	tmp.st_blksize = stat->blksize;
642	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
643}
644
645SYSCALL_DEFINE2(stat64, const char __user *, filename,
646		struct stat64 __user *, statbuf)
647{
648	struct kstat stat;
649	int error = vfs_stat(filename, &stat);
650
651	if (!error)
652		error = cp_new_stat64(&stat, statbuf);
653
654	return error;
655}
656
657SYSCALL_DEFINE2(lstat64, const char __user *, filename,
658		struct stat64 __user *, statbuf)
659{
660	struct kstat stat;
661	int error = vfs_lstat(filename, &stat);
662
663	if (!error)
664		error = cp_new_stat64(&stat, statbuf);
665
666	return error;
667}
668
669SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
670{
671	struct kstat stat;
672	int error = vfs_fstat(fd, &stat);
673
674	if (!error)
675		error = cp_new_stat64(&stat, statbuf);
676
677	return error;
678}
679
680SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
681		struct stat64 __user *, statbuf, int, flag)
682{
683	struct kstat stat;
684	int error;
685
686	error = vfs_fstatat(dfd, filename, &stat, flag);
687	if (error)
688		return error;
689	return cp_new_stat64(&stat, statbuf);
690}
691#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
692
693static noinline_for_stack int
694cp_statx(const struct kstat *stat, struct statx __user *buffer)
695{
696	struct statx tmp;
697
698	memset(&tmp, 0, sizeof(tmp));
699
700	/* STATX_CHANGE_COOKIE is kernel-only for now */
701	tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
702	tmp.stx_blksize = stat->blksize;
703	/* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
704	tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
705	tmp.stx_nlink = stat->nlink;
706	tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
707	tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
708	tmp.stx_mode = stat->mode;
709	tmp.stx_ino = stat->ino;
710	tmp.stx_size = stat->size;
711	tmp.stx_blocks = stat->blocks;
712	tmp.stx_attributes_mask = stat->attributes_mask;
713	tmp.stx_atime.tv_sec = stat->atime.tv_sec;
714	tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
715	tmp.stx_btime.tv_sec = stat->btime.tv_sec;
716	tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
717	tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
718	tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
719	tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
720	tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
721	tmp.stx_rdev_major = MAJOR(stat->rdev);
722	tmp.stx_rdev_minor = MINOR(stat->rdev);
723	tmp.stx_dev_major = MAJOR(stat->dev);
724	tmp.stx_dev_minor = MINOR(stat->dev);
725	tmp.stx_mnt_id = stat->mnt_id;
726	tmp.stx_dio_mem_align = stat->dio_mem_align;
727	tmp.stx_dio_offset_align = stat->dio_offset_align;
728	tmp.stx_subvol = stat->subvol;
729	tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
730	tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
731	tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
732
733	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
734}
735
736int do_statx(int dfd, struct filename *filename, unsigned int flags,
737	     unsigned int mask, struct statx __user *buffer)
738{
739	struct kstat stat;
740	int error;
741
742	if (mask & STATX__RESERVED)
743		return -EINVAL;
744	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
745		return -EINVAL;
746
747	/*
748	 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
749	 * from userland.
750	 */
751	mask &= ~STATX_CHANGE_COOKIE;
752
753	error = vfs_statx(dfd, filename, flags, &stat, mask);
754	if (error)
755		return error;
756
757	return cp_statx(&stat, buffer);
758}
759
760int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
761	     struct statx __user *buffer)
762{
763	struct kstat stat;
764	int error;
765
766	if (mask & STATX__RESERVED)
767		return -EINVAL;
768	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
769		return -EINVAL;
770
771	/*
772	 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
773	 * from userland.
774	 */
775	mask &= ~STATX_CHANGE_COOKIE;
776
777	error = vfs_statx_fd(fd, flags, &stat, mask);
778	if (error)
779		return error;
780
781	return cp_statx(&stat, buffer);
782}
783
784/**
785 * sys_statx - System call to get enhanced stats
786 * @dfd: Base directory to pathwalk from *or* fd to stat.
787 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH
788 * @flags: AT_* flags to control pathwalk.
789 * @mask: Parts of statx struct actually required.
790 * @buffer: Result buffer.
791 *
792 * Note that fstat() can be emulated by setting dfd to the fd of interest,
793 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH
794 * in the flags.
795 */
796SYSCALL_DEFINE5(statx,
797		int, dfd, const char __user *, filename, unsigned, flags,
798		unsigned int, mask,
799		struct statx __user *, buffer)
800{
801	int ret;
802	struct filename *name = getname_maybe_null(filename, flags);
803
804	if (!name && dfd >= 0)
805		return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);
806
807	ret = do_statx(dfd, name, flags, mask, buffer);
808	putname(name);
809
810	return ret;
811}
812
813#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
814static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
815{
816	struct compat_stat tmp;
817
818	if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
819		return -EOVERFLOW;
820	if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
821		return -EOVERFLOW;
822
823	memset(&tmp, 0, sizeof(tmp));
824	tmp.st_dev = new_encode_dev(stat->dev);
825	tmp.st_ino = stat->ino;
826	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
827		return -EOVERFLOW;
828	tmp.st_mode = stat->mode;
829	tmp.st_nlink = stat->nlink;
830	if (tmp.st_nlink != stat->nlink)
831		return -EOVERFLOW;
832	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
833	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
834	tmp.st_rdev = new_encode_dev(stat->rdev);
835	if ((u64) stat->size > MAX_NON_LFS)
836		return -EOVERFLOW;
837	tmp.st_size = stat->size;
838	tmp.st_atime = stat->atime.tv_sec;
839	tmp.st_atime_nsec = stat->atime.tv_nsec;
840	tmp.st_mtime = stat->mtime.tv_sec;
841	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
842	tmp.st_ctime = stat->ctime.tv_sec;
843	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
844	tmp.st_blocks = stat->blocks;
845	tmp.st_blksize = stat->blksize;
846	return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
847}
848
849COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
850		       struct compat_stat __user *, statbuf)
851{
852	struct kstat stat;
853	int error;
854
855	error = vfs_stat(filename, &stat);
856	if (error)
857		return error;
858	return cp_compat_stat(&stat, statbuf);
859}
860
861COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
862		       struct compat_stat __user *, statbuf)
863{
864	struct kstat stat;
865	int error;
866
867	error = vfs_lstat(filename, &stat);
868	if (error)
869		return error;
870	return cp_compat_stat(&stat, statbuf);
871}
872
873#ifndef __ARCH_WANT_STAT64
874COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
875		       const char __user *, filename,
876		       struct compat_stat __user *, statbuf, int, flag)
877{
878	struct kstat stat;
879	int error;
880
881	error = vfs_fstatat(dfd, filename, &stat, flag);
882	if (error)
883		return error;
884	return cp_compat_stat(&stat, statbuf);
885}
886#endif
887
888COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
889		       struct compat_stat __user *, statbuf)
890{
891	struct kstat stat;
892	int error = vfs_fstat(fd, &stat);
893
894	if (!error)
895		error = cp_compat_stat(&stat, statbuf);
896	return error;
897}
898#endif
899
900/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
901void __inode_add_bytes(struct inode *inode, loff_t bytes)
902{
903	inode->i_blocks += bytes >> 9;
904	bytes &= 511;
905	inode->i_bytes += bytes;
906	if (inode->i_bytes >= 512) {
907		inode->i_blocks++;
908		inode->i_bytes -= 512;
909	}
910}
911EXPORT_SYMBOL(__inode_add_bytes);
912
913void inode_add_bytes(struct inode *inode, loff_t bytes)
914{
915	spin_lock(&inode->i_lock);
916	__inode_add_bytes(inode, bytes);
917	spin_unlock(&inode->i_lock);
918}
919
920EXPORT_SYMBOL(inode_add_bytes);
921
922void __inode_sub_bytes(struct inode *inode, loff_t bytes)
923{
924	inode->i_blocks -= bytes >> 9;
925	bytes &= 511;
926	if (inode->i_bytes < bytes) {
927		inode->i_blocks--;
928		inode->i_bytes += 512;
929	}
930	inode->i_bytes -= bytes;
931}
932
933EXPORT_SYMBOL(__inode_sub_bytes);
934
935void inode_sub_bytes(struct inode *inode, loff_t bytes)
936{
937	spin_lock(&inode->i_lock);
938	__inode_sub_bytes(inode, bytes);
939	spin_unlock(&inode->i_lock);
940}
941
942EXPORT_SYMBOL(inode_sub_bytes);
943
944loff_t inode_get_bytes(struct inode *inode)
945{
946	loff_t ret;
947
948	spin_lock(&inode->i_lock);
949	ret = __inode_get_bytes(inode);
950	spin_unlock(&inode->i_lock);
951	return ret;
952}
953
954EXPORT_SYMBOL(inode_get_bytes);
955
956void inode_set_bytes(struct inode *inode, loff_t bytes)
957{
958	/* Caller is here responsible for sufficient locking
959	 * (ie. inode->i_lock) */
960	inode->i_blocks = bytes >> 9;
961	inode->i_bytes = bytes & 511;
962}
963
964EXPORT_SYMBOL(inode_set_bytes);