[mirror_ubuntu-artful-kernel.git] / fs / stat.c

/*
 *  linux/fs/stat.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/export.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/highuid.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/cred.h>
#include <linux/syscalls.h>
#include <linux/pagemap.h>

#include <linux/uaccess.h>
#include <asm/unistd.h>

void generic_fillattr(struct inode *inode, struct kstat *stat)
{
	stat->dev = inode->i_sb->s_dev;
	stat->ino = inode->i_ino;
	stat->mode = inode->i_mode;
	stat->nlink = inode->i_nlink;
	stat->uid = inode->i_uid;
	stat->gid = inode->i_gid;
	stat->rdev = inode->i_rdev;
	stat->size = i_size_read(inode);
	stat->atime = inode->i_atime;
	stat->mtime = inode->i_mtime;
	stat->ctime = inode->i_ctime;
	stat->blksize = i_blocksize(inode);
	stat->blocks = inode->i_blocks;
}

EXPORT_SYMBOL(generic_fillattr);

/**
 * vfs_getattr_nosec - getattr without security checks
 * @path: file to get attributes from
 * @stat: structure to return attributes in
 *
 * Get attributes without calling security_inode_getattr.
 *
 * Currently the only caller other than vfs_getattr is internal to the
 * filehandle lookup code, which uses only the inode number and returns
 * no attributes to any user.  Any other code probably wants
 * vfs_getattr.
 */
int vfs_getattr_nosec(struct path *path, struct kstat *stat)
{
	struct inode *inode = d_backing_inode(path->dentry);

	if (inode->i_op->getattr)
		return inode->i_op->getattr(path->mnt, path->dentry, stat);

	generic_fillattr(inode, stat);
	return 0;
}

EXPORT_SYMBOL(vfs_getattr_nosec);

int vfs_getattr(struct path *path, struct kstat *stat)
{
	int retval;

	retval = security_inode_getattr(path);
	if (retval)
		return retval;
	return vfs_getattr_nosec(path, stat);
}

EXPORT_SYMBOL(vfs_getattr);

int vfs_fstat(unsigned int fd, struct kstat *stat)
{
	struct fd f = fdget_raw(fd);
	int error = -EBADF;

	if (f.file) {
		error = vfs_getattr(&f.file->f_path, stat);
		fdput(f);
	}
	return error;
}
EXPORT_SYMBOL(vfs_fstat);

int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
		int flag)
{
	struct path path;
	int error = -EINVAL;
	unsigned int lookup_flags = 0;

	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
		      AT_EMPTY_PATH)) != 0)
		goto out;

	if (!(flag & AT_SYMLINK_NOFOLLOW))
		lookup_flags |= LOOKUP_FOLLOW;
	if (flag & AT_EMPTY_PATH)
		lookup_flags |= LOOKUP_EMPTY;
retry:
	error = user_path_at(dfd, filename, lookup_flags, &path);
	if (error)
		goto out;

	error = vfs_getattr(&path, stat);
	path_put(&path);
	if (retry_estale(error, lookup_flags)) {
		lookup_flags |= LOOKUP_REVAL;
		goto retry;
	}
out:
	return error;
}
EXPORT_SYMBOL(vfs_fstatat);

int vfs_stat(const char __user *name, struct kstat *stat)
{
	return vfs_fstatat(AT_FDCWD, name, stat, 0);
}
EXPORT_SYMBOL(vfs_stat);

int vfs_lstat(const char __user *name, struct kstat *stat)
{
	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
}
EXPORT_SYMBOL(vfs_lstat);


#ifdef __ARCH_WANT_OLD_STAT

/*
 * For backward compatibility?  Maybe this should be moved
 * into arch/i386 instead?
 */
static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
{
	static int warncount = 5;
	struct __old_kernel_stat tmp;
	
	if (warncount > 0) {
		warncount--;
		printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
			current->comm);
	} else if (warncount < 0) {
		/* it's laughable, but... */
		warncount = 0;
	}

	memset(&tmp, 0, sizeof(struct __old_kernel_stat));
	tmp.st_dev = old_encode_dev(stat->dev);
	tmp.st_ino = stat->ino;
	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
		return -EOVERFLOW;
	tmp.st_mode = stat->mode;
	tmp.st_nlink = stat->nlink;
	if (tmp.st_nlink != stat->nlink)
		return -EOVERFLOW;
	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
	tmp.st_rdev = old_encode_dev(stat->rdev);
#if BITS_PER_LONG == 32
	if (stat->size > MAX_NON_LFS)
		return -EOVERFLOW;
#endif	
	tmp.st_size = stat->size;
	tmp.st_atime = stat->atime.tv_sec;
	tmp.st_mtime = stat->mtime.tv_sec;
	tmp.st_ctime = stat->ctime.tv_sec;
	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(stat, const char __user *, filename,
		struct __old_kernel_stat __user *, statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_stat(filename, &stat);
	if (error)
		return error;

	return cp_old_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(lstat, const char __user *, filename,
		struct __old_kernel_stat __user *, statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_lstat(filename, &stat);
	if (error)
		return error;

	return cp_old_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
		error = cp_old_stat(&stat, statbuf);

	return error;
}

#endif /* __ARCH_WANT_OLD_STAT */

#if BITS_PER_LONG == 32
#  define choose_32_64(a,b) a
#else
#  define choose_32_64(a,b) b
#endif

#define valid_dev(x)  choose_32_64(old_valid_dev(x),true)
#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)

#ifndef INIT_STRUCT_STAT_PADDING
#  define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
#endif

static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
{
	struct stat tmp;

	if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
		return -EOVERFLOW;
#if BITS_PER_LONG == 32
	if (stat->size > MAX_NON_LFS)
		return -EOVERFLOW;
#endif

	INIT_STRUCT_STAT_PADDING(tmp);
	tmp.st_dev = encode_dev(stat->dev);
	tmp.st_ino = stat->ino;
	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
		return -EOVERFLOW;
	tmp.st_mode = stat->mode;
	tmp.st_nlink = stat->nlink;
	if (tmp.st_nlink != stat->nlink)
		return -EOVERFLOW;
	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
	tmp.st_rdev = encode_dev(stat->rdev);
	tmp.st_size = stat->size;
	tmp.st_atime = stat->atime.tv_sec;
	tmp.st_mtime = stat->mtime.tv_sec;
	tmp.st_ctime = stat->ctime.tv_sec;
#ifdef STAT_HAVE_NSEC
	tmp.st_atime_nsec = stat->atime.tv_nsec;
	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
#endif
	tmp.st_blocks = stat->blocks;
	tmp.st_blksize = stat->blksize;
	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(newstat, const char __user *, filename,
		struct stat __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_stat(filename, &stat);

	if (error)
		return error;
	return cp_new_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(newlstat, const char __user *, filename,
		struct stat __user *, statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_lstat(filename, &stat);
	if (error)
		return error;

	return cp_new_stat(&stat, statbuf);
}

#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
		struct stat __user *, statbuf, int, flag)
{
	struct kstat stat;
	int error;

	error = vfs_fstatat(dfd, filename, &stat, flag);
	if (error)
		return error;
	return cp_new_stat(&stat, statbuf);
}
#endif

SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
		error = cp_new_stat(&stat, statbuf);

	return error;
}

SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
		char __user *, buf, int, bufsiz)
{
	struct path path;
	int error;
	int empty = 0;
	unsigned int lookup_flags = LOOKUP_EMPTY;

	if (bufsiz <= 0)
		return -EINVAL;

retry:
	error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
	if (!error) {
		struct inode *inode = d_backing_inode(path.dentry);

		error = empty ? -ENOENT : -EINVAL;
		/*
		 * AFS mountpoints allow readlink(2) but are not symlinks
		 */
		if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
			error = security_inode_readlink(path.dentry);
			if (!error) {
				touch_atime(&path);
				error = vfs_readlink(path.dentry, buf, bufsiz);
			}
		}
		path_put(&path);
		if (retry_estale(error, lookup_flags)) {
			lookup_flags |= LOOKUP_REVAL;
			goto retry;
		}
	}
	return error;
}

SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
		int, bufsiz)
{
	return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
}


/* ---------- LFS-64 ----------- */
#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)

#ifndef INIT_STRUCT_STAT64_PADDING
#  define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
#endif

static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
{
	struct stat64 tmp;

	INIT_STRUCT_STAT64_PADDING(tmp);
#ifdef CONFIG_MIPS
	/* mips has weird padding, so we don't get 64 bits there */
	tmp.st_dev = new_encode_dev(stat->dev);
	tmp.st_rdev = new_encode_dev(stat->rdev);
#else
	tmp.st_dev = huge_encode_dev(stat->dev);
	tmp.st_rdev = huge_encode_dev(stat->rdev);
#endif
	tmp.st_ino = stat->ino;
	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
		return -EOVERFLOW;
#ifdef STAT64_HAS_BROKEN_ST_INO
	tmp.__st_ino = stat->ino;
#endif
	tmp.st_mode = stat->mode;
	tmp.st_nlink = stat->nlink;
	tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
	tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
	tmp.st_atime = stat->atime.tv_sec;
	tmp.st_atime_nsec = stat->atime.tv_nsec;
	tmp.st_mtime = stat->mtime.tv_sec;
	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	tmp.st_ctime = stat->ctime.tv_sec;
	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
	tmp.st_size = stat->size;
	tmp.st_blocks = stat->blocks;
	tmp.st_blksize = stat->blksize;
	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(stat64, const char __user *, filename,
		struct stat64 __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_stat(filename, &stat);

	if (!error)
		error = cp_new_stat64(&stat, statbuf);

	return error;
}

SYSCALL_DEFINE2(lstat64, const char __user *, filename,
		struct stat64 __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_lstat(filename, &stat);

	if (!error)
		error = cp_new_stat64(&stat, statbuf);

	return error;
}

SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
		error = cp_new_stat64(&stat, statbuf);

	return error;
}

SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
		struct stat64 __user *, statbuf, int, flag)
{
	struct kstat stat;
	int error;

	error = vfs_fstatat(dfd, filename, &stat, flag);
	if (error)
		return error;
	return cp_new_stat64(&stat, statbuf);
}
#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */

/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
void __inode_add_bytes(struct inode *inode, loff_t bytes)
{
	inode->i_blocks += bytes >> 9;
	bytes &= 511;
	inode->i_bytes += bytes;
	if (inode->i_bytes >= 512) {
		inode->i_blocks++;
		inode->i_bytes -= 512;
	}
}

void inode_add_bytes(struct inode *inode, loff_t bytes)
{
	spin_lock(&inode->i_lock);
	__inode_add_bytes(inode, bytes);
	spin_unlock(&inode->i_lock);
}

EXPORT_SYMBOL(inode_add_bytes);

void __inode_sub_bytes(struct inode *inode, loff_t bytes)
{
	inode->i_blocks -= bytes >> 9;
	bytes &= 511;
	if (inode->i_bytes < bytes) {
		inode->i_blocks--;
		inode->i_bytes += 512;
	}
	inode->i_bytes -= bytes;
}

EXPORT_SYMBOL(__inode_sub_bytes);

void inode_sub_bytes(struct inode *inode, loff_t bytes)
{
	spin_lock(&inode->i_lock);
	__inode_sub_bytes(inode, bytes);
	spin_unlock(&inode->i_lock);
}

EXPORT_SYMBOL(inode_sub_bytes);

loff_t inode_get_bytes(struct inode *inode)
{
	loff_t ret;

	spin_lock(&inode->i_lock);
	ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
	spin_unlock(&inode->i_lock);
	return ret;
}

EXPORT_SYMBOL(inode_get_bytes);

void inode_set_bytes(struct inode *inode, loff_t bytes)
{
	/* Caller is here responsible for sufficient locking
	 * (ie. inode->i_lock) */
	inode->i_blocks = bytes >> 9;
	inode->i_bytes = bytes & 511;
}

EXPORT_SYMBOL(inode_set_bytes);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/stat.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
630d9c47	7	#include <linux/export.h>
1da177e4 LT	8	#include <linux/mm.h>
	9	#include <linux/errno.h>
	10	#include <linux/file.h>
1da177e4 LT	11	#include <linux/highuid.h>
	12	#include <linux/fs.h>
	13	#include <linux/namei.h>
	14	#include <linux/security.h>
5b825c3a	15	#include <linux/cred.h>
1da177e4	16	#include <linux/syscalls.h>
ba52de12	17	#include <linux/pagemap.h>
1da177e4	18
7c0f6ba6	19	#include <linux/uaccess.h>
1da177e4 LT	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;
3ddcd056	31	stat->size = i_size_read(inode);
1da177e4 LT	32	stat->atime = inode->i_atime;
	33	stat->mtime = inode->i_mtime;
	34	stat->ctime = inode->i_ctime;
93407472	35	stat->blksize = i_blocksize(inode);
3ddcd056	36	stat->blocks = inode->i_blocks;
1da177e4 LT	37	}
	38
	39	EXPORT_SYMBOL(generic_fillattr);
	40
b7a6ec52 BF	41	/**
	42	* vfs_getattr_nosec - getattr without security checks
	43	* @path: file to get attributes from
	44	* @stat: structure to return attributes in
	45	*
	46	* Get attributes without calling security_inode_getattr.
	47	*
	48	* Currently the only caller other than vfs_getattr is internal to the
	49	* filehandle lookup code, which uses only the inode number and returns
	50	* no attributes to any user. Any other code probably wants
	51	* vfs_getattr.
	52	*/
	53	int vfs_getattr_nosec(struct path path, struct kstat stat)
1da177e4	54	{
bb668734	55	struct inode *inode = d_backing_inode(path->dentry);
1da177e4 LT	56
1da177e4 LT	57	if (inode->i_op->getattr)
3dadecce	58	return inode->i_op->getattr(path->mnt, path->dentry, stat);
1da177e4 LT	59
1da177e4 LT	60	generic_fillattr(inode, stat);
1da177e4 LT	61	return 0;
	62	}
	63
b7a6ec52 BF	64	EXPORT_SYMBOL(vfs_getattr_nosec);
	65
	66	int vfs_getattr(struct path path, struct kstat stat)
	67	{
	68	int retval;
	69
3f7036a0	70	retval = security_inode_getattr(path);
b7a6ec52 BF	71	if (retval)
	72	return retval;
	73	return vfs_getattr_nosec(path, stat);
	74	}
	75
1da177e4 LT	76	EXPORT_SYMBOL(vfs_getattr);
1da177e4 LT	77
1da177e4 LT	78	int vfs_fstat(unsigned int fd, struct kstat *stat)
1da177e4 LT	79	{
2903ff01	80	struct fd f = fdget_raw(fd);
1da177e4 LT	81	int error = -EBADF;
1da177e4 LT	82
2903ff01	83	if (f.file) {
3dadecce	84	error = vfs_getattr(&f.file->f_path, stat);
2903ff01	85	fdput(f);
1da177e4 LT	86	}
	87	return error;
	88	}
1da177e4 LT	89	EXPORT_SYMBOL(vfs_fstat);
1da177e4 LT	90
c7887325 DH	91	int vfs_fstatat(int dfd, const char __user filename, struct kstat stat,
c7887325 DH	92	int flag)
0112fc22	93	{
2eae7a18	94	struct path path;
0112fc22	95	int error = -EINVAL;
836fb7e7	96	unsigned int lookup_flags = 0;
0112fc22	97
65cfc672 AV	98	if ((flag & ~(AT_SYMLINK_NOFOLLOW \| AT_NO_AUTOMOUNT \|
65cfc672 AV	99	AT_EMPTY_PATH)) != 0)
0112fc22 OD	100	goto out;
0112fc22 OD	101
2eae7a18 CH	102	if (!(flag & AT_SYMLINK_NOFOLLOW))
2eae7a18 CH	103	lookup_flags \|= LOOKUP_FOLLOW;
65cfc672 AV	104	if (flag & AT_EMPTY_PATH)
65cfc672 AV	105	lookup_flags \|= LOOKUP_EMPTY;
836fb7e7	106	retry:
2eae7a18 CH	107	error = user_path_at(dfd, filename, lookup_flags, &path);
	108	if (error)
	109	goto out;
	110
3dadecce	111	error = vfs_getattr(&path, stat);
2eae7a18	112	path_put(&path);
836fb7e7 JL	113	if (retry_estale(error, lookup_flags)) {
	114	lookup_flags \|= LOOKUP_REVAL;
	115	goto retry;
	116	}
0112fc22 OD	117	out:
	118	return error;
	119	}
0112fc22 OD	120	EXPORT_SYMBOL(vfs_fstatat);
0112fc22 OD	121
c7887325	122	int vfs_stat(const char __user name, struct kstat stat)
2eae7a18 CH	123	{
	124	return vfs_fstatat(AT_FDCWD, name, stat, 0);
	125	}
	126	EXPORT_SYMBOL(vfs_stat);
	127
c7887325	128	int vfs_lstat(const char __user name, struct kstat stat)
2eae7a18 CH	129	{
	130	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
	131	}
	132	EXPORT_SYMBOL(vfs_lstat);
	133
0112fc22	134
1da177e4 LT	135	#ifdef __ARCH_WANT_OLD_STAT
	136
	137	/*
	138	* For backward compatibility? Maybe this should be moved
	139	* into arch/i386 instead?
	140	*/
	141	static int cp_old_stat(struct kstat stat, struct __old_kernel_stat __user statbuf)
	142	{
	143	static int warncount = 5;
	144	struct __old_kernel_stat tmp;
	145
	146	if (warncount > 0) {
	147	warncount--;
	148	printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
	149	current->comm);
	150	} else if (warncount < 0) {
	151	/* it's laughable, but... */
	152	warncount = 0;
	153	}
	154
	155	memset(&tmp, 0, sizeof(struct __old_kernel_stat));
	156	tmp.st_dev = old_encode_dev(stat->dev);
	157	tmp.st_ino = stat->ino;
afefdbb2 DH	158	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
afefdbb2 DH	159	return -EOVERFLOW;
1da177e4 LT	160	tmp.st_mode = stat->mode;
	161	tmp.st_nlink = stat->nlink;
	162	if (tmp.st_nlink != stat->nlink)
	163	return -EOVERFLOW;
a7c1938e EB	164	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
a7c1938e EB	165	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
1da177e4 LT	166	tmp.st_rdev = old_encode_dev(stat->rdev);
	167	#if BITS_PER_LONG == 32
	168	if (stat->size > MAX_NON_LFS)
	169	return -EOVERFLOW;
	170	#endif
	171	tmp.st_size = stat->size;
	172	tmp.st_atime = stat->atime.tv_sec;
	173	tmp.st_mtime = stat->mtime.tv_sec;
	174	tmp.st_ctime = stat->ctime.tv_sec;
	175	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
	176	}
	177
c7887325 DH	178	SYSCALL_DEFINE2(stat, const char __user *, filename,
c7887325 DH	179	struct __old_kernel_stat __user *, statbuf)
1da177e4 LT	180	{
1da177e4 LT	181	struct kstat stat;
2eae7a18	182	int error;
1da177e4	183
2eae7a18 CH	184	error = vfs_stat(filename, &stat);
	185	if (error)
	186	return error;
1da177e4	187
2eae7a18	188	return cp_old_stat(&stat, statbuf);
1da177e4	189	}
257ac264	190
c7887325 DH	191	SYSCALL_DEFINE2(lstat, const char __user *, filename,
c7887325 DH	192	struct __old_kernel_stat __user *, statbuf)
1da177e4 LT	193	{
1da177e4 LT	194	struct kstat stat;
2eae7a18	195	int error;
1da177e4	196
2eae7a18 CH	197	error = vfs_lstat(filename, &stat);
	198	if (error)
	199	return error;
1da177e4	200
2eae7a18	201	return cp_old_stat(&stat, statbuf);
1da177e4	202	}
257ac264 HC	203
257ac264 HC	204	SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
1da177e4 LT	205	{
	206	struct kstat stat;
	207	int error = vfs_fstat(fd, &stat);
	208
	209	if (!error)
	210	error = cp_old_stat(&stat, statbuf);
	211
	212	return error;
	213	}
	214
	215	#endif /* __ARCH_WANT_OLD_STAT */
	216
a52dd971 LT	217	#if BITS_PER_LONG == 32
	218	# define choose_32_64(a,b) a
	219	#else
	220	# define choose_32_64(a,b) b
	221	#endif
	222
4c416f42	223	#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
a52dd971 LT	224	#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
a52dd971 LT	225
8529f613 LT	226	#ifndef INIT_STRUCT_STAT_PADDING
	227	# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
	228	#endif
	229
1da177e4 LT	230	static int cp_new_stat(struct kstat stat, struct stat __user statbuf)
	231	{
	232	struct stat tmp;
	233
a52dd971	234	if (!valid_dev(stat->dev) \|\| !valid_dev(stat->rdev))
1da177e4	235	return -EOVERFLOW;
a52dd971 LT	236	#if BITS_PER_LONG == 32
a52dd971 LT	237	if (stat->size > MAX_NON_LFS)
1da177e4 LT	238	return -EOVERFLOW;
	239	#endif
	240
8529f613	241	INIT_STRUCT_STAT_PADDING(tmp);
a52dd971	242	tmp.st_dev = encode_dev(stat->dev);
1da177e4	243	tmp.st_ino = stat->ino;
afefdbb2 DH	244	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
afefdbb2 DH	245	return -EOVERFLOW;
1da177e4 LT	246	tmp.st_mode = stat->mode;
	247	tmp.st_nlink = stat->nlink;
	248	if (tmp.st_nlink != stat->nlink)
	249	return -EOVERFLOW;
a7c1938e EB	250	SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
a7c1938e EB	251	SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
a52dd971	252	tmp.st_rdev = encode_dev(stat->rdev);
1da177e4 LT	253	tmp.st_size = stat->size;
	254	tmp.st_atime = stat->atime.tv_sec;
	255	tmp.st_mtime = stat->mtime.tv_sec;
	256	tmp.st_ctime = stat->ctime.tv_sec;
	257	#ifdef STAT_HAVE_NSEC
	258	tmp.st_atime_nsec = stat->atime.tv_nsec;
	259	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	260	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
	261	#endif
	262	tmp.st_blocks = stat->blocks;
	263	tmp.st_blksize = stat->blksize;
	264	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
	265	}
	266
c7887325 DH	267	SYSCALL_DEFINE2(newstat, const char __user *, filename,
c7887325 DH	268	struct stat __user *, statbuf)
5590ff0d UD	269	{
5590ff0d UD	270	struct kstat stat;
2eae7a18	271	int error = vfs_stat(filename, &stat);
5590ff0d	272
2eae7a18 CH	273	if (error)
	274	return error;
	275	return cp_new_stat(&stat, statbuf);
5590ff0d UD	276	}
5590ff0d UD	277
c7887325 DH	278	SYSCALL_DEFINE2(newlstat, const char __user *, filename,
c7887325 DH	279	struct stat __user *, statbuf)
1da177e4 LT	280	{
1da177e4 LT	281	struct kstat stat;
2eae7a18	282	int error;
1da177e4	283
2eae7a18 CH	284	error = vfs_lstat(filename, &stat);
	285	if (error)
	286	return error;
1da177e4	287
2eae7a18	288	return cp_new_stat(&stat, statbuf);
1da177e4	289	}
5590ff0d	290
2833c28a	291	#if !defined(__ARCH_WANT_STAT64) \|\| defined(__ARCH_WANT_SYS_NEWFSTATAT)
c7887325	292	SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
6559eed8	293	struct stat __user *, statbuf, int, flag)
1da177e4 LT	294	{
1da177e4 LT	295	struct kstat stat;
0112fc22	296	int error;
1da177e4	297
0112fc22 OD	298	error = vfs_fstatat(dfd, filename, &stat, flag);
	299	if (error)
	300	return error;
	301	return cp_new_stat(&stat, statbuf);
1da177e4	302	}
cff2b760	303	#endif
5590ff0d	304
257ac264	305	SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
1da177e4 LT	306	{
	307	struct kstat stat;
	308	int error = vfs_fstat(fd, &stat);
	309
	310	if (!error)
	311	error = cp_new_stat(&stat, statbuf);
	312
	313	return error;
	314	}
	315
6559eed8 HC	316	SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
6559eed8 HC	317	char __user *, buf, int, bufsiz)
1da177e4	318	{
2d8f3038	319	struct path path;
1da177e4	320	int error;
1fa1e7f6	321	int empty = 0;
7955119e	322	unsigned int lookup_flags = LOOKUP_EMPTY;
1da177e4 LT	323
	324	if (bufsiz <= 0)
	325	return -EINVAL;
	326
7955119e JL	327	retry:
7955119e JL	328	error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
1da177e4	329	if (!error) {
bb668734	330	struct inode *inode = d_backing_inode(path.dentry);
1da177e4	331
1fa1e7f6	332	error = empty ? -ENOENT : -EINVAL;
fd4a0edf MS	333	/*
	334	* AFS mountpoints allow readlink(2) but are not symlinks
	335	*/
	336	if (d_is_symlink(path.dentry) \|\| inode->i_op->readlink) {
2d8f3038	337	error = security_inode_readlink(path.dentry);
1da177e4	338	if (!error) {
68ac1234	339	touch_atime(&path);
fd4a0edf	340	error = vfs_readlink(path.dentry, buf, bufsiz);
1da177e4 LT	341	}
1da177e4 LT	342	}
2d8f3038	343	path_put(&path);
7955119e JL	344	if (retry_estale(error, lookup_flags)) {
	345	lookup_flags \|= LOOKUP_REVAL;
	346	goto retry;
	347	}
1da177e4 LT	348	}
	349	return error;
	350	}
	351
002c8976 HC	352	SYSCALL_DEFINE3(readlink, const char __user , path, char __user , buf,
002c8976 HC	353	int, bufsiz)
5590ff0d UD	354	{
	355	return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
	356	}
	357
1da177e4 LT	358
1da177e4 LT	359	/* ---------- LFS-64 ----------- */
0753f70f	360	#if defined(__ARCH_WANT_STAT64) \|\| defined(__ARCH_WANT_COMPAT_STAT64)
1da177e4	361
8529f613 LT	362	#ifndef INIT_STRUCT_STAT64_PADDING
	363	# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
	364	#endif
	365
1da177e4 LT	366	static long cp_new_stat64(struct kstat stat, struct stat64 __user statbuf)
	367	{
	368	struct stat64 tmp;
	369
8529f613	370	INIT_STRUCT_STAT64_PADDING(tmp);
1da177e4 LT	371	#ifdef CONFIG_MIPS
1da177e4 LT	372	/* mips has weird padding, so we don't get 64 bits there */
1da177e4 LT	373	tmp.st_dev = new_encode_dev(stat->dev);
	374	tmp.st_rdev = new_encode_dev(stat->rdev);
	375	#else
	376	tmp.st_dev = huge_encode_dev(stat->dev);
	377	tmp.st_rdev = huge_encode_dev(stat->rdev);
	378	#endif
	379	tmp.st_ino = stat->ino;
afefdbb2 DH	380	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
afefdbb2 DH	381	return -EOVERFLOW;
1da177e4 LT	382	#ifdef STAT64_HAS_BROKEN_ST_INO
	383	tmp.__st_ino = stat->ino;
	384	#endif
	385	tmp.st_mode = stat->mode;
	386	tmp.st_nlink = stat->nlink;
a7c1938e EB	387	tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
a7c1938e EB	388	tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
1da177e4 LT	389	tmp.st_atime = stat->atime.tv_sec;
	390	tmp.st_atime_nsec = stat->atime.tv_nsec;
	391	tmp.st_mtime = stat->mtime.tv_sec;
	392	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	393	tmp.st_ctime = stat->ctime.tv_sec;
	394	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
	395	tmp.st_size = stat->size;
	396	tmp.st_blocks = stat->blocks;
	397	tmp.st_blksize = stat->blksize;
	398	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
	399	}
	400
c7887325 DH	401	SYSCALL_DEFINE2(stat64, const char __user *, filename,
c7887325 DH	402	struct stat64 __user *, statbuf)
1da177e4 LT	403	{
	404	struct kstat stat;
	405	int error = vfs_stat(filename, &stat);
	406
	407	if (!error)
	408	error = cp_new_stat64(&stat, statbuf);
	409
	410	return error;
	411	}
257ac264	412
c7887325 DH	413	SYSCALL_DEFINE2(lstat64, const char __user *, filename,
c7887325 DH	414	struct stat64 __user *, statbuf)
1da177e4 LT	415	{
	416	struct kstat stat;
	417	int error = vfs_lstat(filename, &stat);
	418
	419	if (!error)
	420	error = cp_new_stat64(&stat, statbuf);
	421
	422	return error;
	423	}
257ac264 HC	424
257ac264 HC	425	SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
1da177e4 LT	426	{
	427	struct kstat stat;
	428	int error = vfs_fstat(fd, &stat);
	429
	430	if (!error)
	431	error = cp_new_stat64(&stat, statbuf);
	432
	433	return error;
	434	}
	435
c7887325	436	SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
6559eed8	437	struct stat64 __user *, statbuf, int, flag)
cff2b760 UD	438	{
cff2b760 UD	439	struct kstat stat;
0112fc22	440	int error;
cff2b760	441
0112fc22 OD	442	error = vfs_fstatat(dfd, filename, &stat, flag);
	443	if (error)
	444	return error;
	445	return cp_new_stat64(&stat, statbuf);
cff2b760	446	}
0753f70f	447	#endif /* __ARCH_WANT_STAT64 \|\| __ARCH_WANT_COMPAT_STAT64 */
1da177e4	448
b462707e DM	449	/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
b462707e DM	450	void __inode_add_bytes(struct inode *inode, loff_t bytes)
1da177e4	451	{
1da177e4 LT	452	inode->i_blocks += bytes >> 9;
	453	bytes &= 511;
	454	inode->i_bytes += bytes;
	455	if (inode->i_bytes >= 512) {
	456	inode->i_blocks++;
	457	inode->i_bytes -= 512;
	458	}
b462707e DM	459	}
	460
	461	void inode_add_bytes(struct inode *inode, loff_t bytes)
	462	{
	463	spin_lock(&inode->i_lock);
	464	__inode_add_bytes(inode, bytes);
1da177e4 LT	465	spin_unlock(&inode->i_lock);
	466	}
	467
	468	EXPORT_SYMBOL(inode_add_bytes);
	469
1c8924eb	470	void __inode_sub_bytes(struct inode *inode, loff_t bytes)
1da177e4	471	{
1da177e4 LT	472	inode->i_blocks -= bytes >> 9;
	473	bytes &= 511;
	474	if (inode->i_bytes < bytes) {
	475	inode->i_blocks--;
	476	inode->i_bytes += 512;
	477	}
	478	inode->i_bytes -= bytes;
1c8924eb JK	479	}
	480
	481	EXPORT_SYMBOL(__inode_sub_bytes);
	482
	483	void inode_sub_bytes(struct inode *inode, loff_t bytes)
	484	{
	485	spin_lock(&inode->i_lock);
	486	__inode_sub_bytes(inode, bytes);
1da177e4 LT	487	spin_unlock(&inode->i_lock);
	488	}
	489
	490	EXPORT_SYMBOL(inode_sub_bytes);
	491
	492	loff_t inode_get_bytes(struct inode *inode)
	493	{
	494	loff_t ret;
	495
	496	spin_lock(&inode->i_lock);
	497	ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
	498	spin_unlock(&inode->i_lock);
	499	return ret;
	500	}
	501
	502	EXPORT_SYMBOL(inode_get_bytes);
	503
	504	void inode_set_bytes(struct inode *inode, loff_t bytes)
	505	{
	506	/* Caller is here responsible for sufficient locking
	507	* (ie. inode->i_lock) */
	508	inode->i_blocks = bytes >> 9;
	509	inode->i_bytes = bytes & 511;
	510	}
	511
	512	EXPORT_SYMBOL(inode_set_bytes);