[deliverable/linux.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/syscalls.h>
#include <linux/pagemap.h>

#include <asm/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 = (1 << inode->i_blkbits);
	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 = path->dentry->d_inode;

	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->mnt, path->dentry);
	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,new_valid_dev)(x)
#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 = path.dentry->d_inode;

		error = empty ? -ENOENT : -EINVAL;
		if (inode->i_op->readlink) {
			error = security_inode_readlink(path.dentry);
			if (!error) {
				touch_atime(&path);
				error = inode->i_op->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 */
	if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
		return -EOVERFLOW;
	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
	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
	21	void 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
	38	EXPORT_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	*/
	52	int vfs_getattr_nosec(struct path path, struct kstat stat)
	53	{
	54	struct inode *inode = path->dentry->d_inode;
	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
	63	EXPORT_SYMBOL(vfs_getattr_nosec);
	64
	65	int vfs_getattr(struct path path, struct kstat stat)
	66	{
	67	int retval;
	68
	69	retval = security_inode_getattr(path->mnt, path->dentry);
	70	if (retval)
	71	return retval;
	72	return vfs_getattr_nosec(path, stat);
	73	}
	74
	75	EXPORT_SYMBOL(vfs_getattr);
	76
	77	int 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	}
	88	EXPORT_SYMBOL(vfs_fstat);
	89
	90	int 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;
	105	retry:
	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	}
	116	out:
	117	return error;
	118	}
	119	EXPORT_SYMBOL(vfs_fstatat);
	120
	121	int vfs_stat(const char __user name, struct kstat stat)
	122	{
	123	return vfs_fstatat(AT_FDCWD, name, stat, 0);
	124	}
	125	EXPORT_SYMBOL(vfs_stat);
	126
	127	int vfs_lstat(const char __user name, struct kstat stat)
	128	{
	129	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
	130	}
	131	EXPORT_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	*/
	140	static 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
	177	SYSCALL_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
	190	SYSCALL_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
	203	SYSCALL_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,new_valid_dev)(x)
	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
	229	static 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
	266	SYSCALL_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
	277	SYSCALL_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)
	291	SYSCALL_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
	304	SYSCALL_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
	315	SYSCALL_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
	326	retry:
	327	error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
	328	if (!error) {
	329	struct inode *inode = path.dentry->d_inode;
	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
	349	SYSCALL_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
	363	static 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	if (!new_valid_dev(stat->dev) \|\| !new_valid_dev(stat->rdev))
	371	return -EOVERFLOW;
	372	tmp.st_dev = new_encode_dev(stat->dev);
	373	tmp.st_rdev = new_encode_dev(stat->rdev);
	374	#else
	375	tmp.st_dev = huge_encode_dev(stat->dev);
	376	tmp.st_rdev = huge_encode_dev(stat->rdev);
	377	#endif
	378	tmp.st_ino = stat->ino;
	379	if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
	380	return -EOVERFLOW;
	381	#ifdef STAT64_HAS_BROKEN_ST_INO
	382	tmp.__st_ino = stat->ino;
	383	#endif
	384	tmp.st_mode = stat->mode;
	385	tmp.st_nlink = stat->nlink;
	386	tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
	387	tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
	388	tmp.st_atime = stat->atime.tv_sec;
	389	tmp.st_atime_nsec = stat->atime.tv_nsec;
	390	tmp.st_mtime = stat->mtime.tv_sec;
	391	tmp.st_mtime_nsec = stat->mtime.tv_nsec;
	392	tmp.st_ctime = stat->ctime.tv_sec;
	393	tmp.st_ctime_nsec = stat->ctime.tv_nsec;
	394	tmp.st_size = stat->size;
	395	tmp.st_blocks = stat->blocks;
	396	tmp.st_blksize = stat->blksize;
	397	return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
	398	}
	399
	400	SYSCALL_DEFINE2(stat64, const char __user *, filename,
	401	struct stat64 __user *, statbuf)
	402	{
	403	struct kstat stat;
	404	int error = vfs_stat(filename, &stat);
	405
	406	if (!error)
	407	error = cp_new_stat64(&stat, statbuf);
	408
	409	return error;
	410	}
	411
	412	SYSCALL_DEFINE2(lstat64, const char __user *, filename,
	413	struct stat64 __user *, statbuf)
	414	{
	415	struct kstat stat;
	416	int error = vfs_lstat(filename, &stat);
	417
	418	if (!error)
	419	error = cp_new_stat64(&stat, statbuf);
	420
	421	return error;
	422	}
	423
	424	SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
	425	{
	426	struct kstat stat;
	427	int error = vfs_fstat(fd, &stat);
	428
	429	if (!error)
	430	error = cp_new_stat64(&stat, statbuf);
	431
	432	return error;
	433	}
	434
	435	SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
	436	struct stat64 __user *, statbuf, int, flag)
	437	{
	438	struct kstat stat;
	439	int error;
	440
	441	error = vfs_fstatat(dfd, filename, &stat, flag);
	442	if (error)
	443	return error;
	444	return cp_new_stat64(&stat, statbuf);
	445	}
	446	#endif /* __ARCH_WANT_STAT64 \|\| __ARCH_WANT_COMPAT_STAT64 */
	447
	448	/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
	449	void __inode_add_bytes(struct inode *inode, loff_t bytes)
	450	{
	451	inode->i_blocks += bytes >> 9;
	452	bytes &= 511;
	453	inode->i_bytes += bytes;
	454	if (inode->i_bytes >= 512) {
	455	inode->i_blocks++;
	456	inode->i_bytes -= 512;
	457	}
	458	}
	459
	460	void inode_add_bytes(struct inode *inode, loff_t bytes)
	461	{
	462	spin_lock(&inode->i_lock);
	463	__inode_add_bytes(inode, bytes);
	464	spin_unlock(&inode->i_lock);
	465	}
	466
	467	EXPORT_SYMBOL(inode_add_bytes);
	468
	469	void __inode_sub_bytes(struct inode *inode, loff_t bytes)
	470	{
	471	inode->i_blocks -= bytes >> 9;
	472	bytes &= 511;
	473	if (inode->i_bytes < bytes) {
	474	inode->i_blocks--;
	475	inode->i_bytes += 512;
	476	}
	477	inode->i_bytes -= bytes;
	478	}
	479
	480	EXPORT_SYMBOL(__inode_sub_bytes);
	481
	482	void inode_sub_bytes(struct inode *inode, loff_t bytes)
	483	{
	484	spin_lock(&inode->i_lock);
	485	__inode_sub_bytes(inode, bytes);
	486	spin_unlock(&inode->i_lock);
	487	}
	488
	489	EXPORT_SYMBOL(inode_sub_bytes);
	490
	491	loff_t inode_get_bytes(struct inode *inode)
	492	{
	493	loff_t ret;
	494
	495	spin_lock(&inode->i_lock);
	496	ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
	497	spin_unlock(&inode->i_lock);
	498	return ret;
	499	}
	500
	501	EXPORT_SYMBOL(inode_get_bytes);
	502
	503	void inode_set_bytes(struct inode *inode, loff_t bytes)
	504	{
	505	/* Caller is here responsible for sufficient locking
	506	* (ie. inode->i_lock) */
	507	inode->i_blocks = bytes >> 9;
	508	inode->i_bytes = bytes & 511;
	509	}
	510
	511	EXPORT_SYMBOL(inode_set_bytes);