fs/stat.c - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  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/compat.h>

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

 /**
  * generic_fillattr - Fill in the basic attributes from the inode struct
  * @inode: Inode to use as the source
  * @stat: Where to fill in the attributes
  *
  * Fill in the basic attributes in the kstat structure from data that's to be
  * found on the VFS inode structure.  This is the default if no getattr inode
  * operation is supplied.
  */
 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;

 	if (IS_NOATIME(inode))
 		stat->result_mask &= ~STATX_ATIME;
 	if (IS_AUTOMOUNT(inode))
 		stat->attributes |= STATX_ATTR_AUTOMOUNT;
 }
 EXPORT_SYMBOL(generic_fillattr);

 /**
  * vfs_getattr_nosec - getattr without security checks
  * @path: file to get attributes from
  * @stat: structure to return attributes in
  * @request_mask: STATX_xxx flags indicating what the caller wants
  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  *
  * 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(const struct path *path, struct kstat *stat,
 		      u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_backing_inode(path->dentry);

 	memset(stat, 0, sizeof(*stat));
 	stat->result_mask |= STATX_BASIC_STATS;
 	request_mask &= STATX_ALL;
 	query_flags &= KSTAT_QUERY_FLAGS;
 	if (inode->i_op->getattr)
 		return inode->i_op->getattr(path, stat, request_mask,
 					    query_flags);

 	generic_fillattr(inode, stat);
 	return 0;
 }
 EXPORT_SYMBOL(vfs_getattr_nosec);

 /*
  * vfs_getattr - Get the enhanced basic attributes of a file
  * @path: The file of interest
  * @stat: Where to return the statistics
  * @request_mask: STATX_xxx flags indicating what the caller wants
  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  *
  * Ask the filesystem for a file's attributes.  The caller must indicate in
  * request_mask and query_flags to indicate what they want.
  *
  * If the file is remote, the filesystem can be forced to update the attributes
  * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
  * suppress the update by passing AT_STATX_DONT_SYNC.
  *
  * Bits must have been set in request_mask to indicate which attributes the
  * caller wants retrieving.  Any such attribute not requested may be returned
  * anyway, but the value may be approximate, and, if remote, may not have been
  * synchronised with the server.
  *
  * 0 will be returned on success, and a -ve error code if unsuccessful.
  */
 int vfs_getattr(const struct path *path, struct kstat *stat,
 		u32 request_mask, unsigned int query_flags)
 {
 	int retval;

 	retval = security_inode_getattr(path);
 	if (retval)
 		return retval;
 	return vfs_getattr_nosec(path, stat, request_mask, query_flags);
 }
 EXPORT_SYMBOL(vfs_getattr);

 /**
  * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
  * @fd: The file descriptor referring to the file of interest
  * @stat: The result structure to fill in.
  * @request_mask: STATX_xxx flags indicating what the caller wants
  * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
  *
  * This function is a wrapper around vfs_getattr().  The main difference is
  * that it uses a file descriptor to determine the file location.
  *
  * 0 will be returned on success, and a -ve error code if unsuccessful.
  */
 int vfs_statx_fd(unsigned int fd, struct kstat *stat,
 		 u32 request_mask, unsigned int query_flags)
 {
 	struct fd f;
 	int error = -EBADF;

 	if (query_flags & ~KSTAT_QUERY_FLAGS)
 		return -EINVAL;

 	f = fdget_raw(fd);
 	if (f.file) {
 		error = vfs_getattr(&f.file->f_path, stat,
 				    request_mask, query_flags);
 		fdput(f);
 	}
 	return error;
 }
 EXPORT_SYMBOL(vfs_statx_fd);

 /**
  * vfs_statx - Get basic and extra attributes by filename
  * @dfd: A file descriptor representing the base dir for a relative filename
  * @filename: The name of the file of interest
  * @flags: Flags to control the query
  * @stat: The result structure to fill in.
  * @request_mask: STATX_xxx flags indicating what the caller wants
  *
  * This function is a wrapper around vfs_getattr().  The main difference is
  * that it uses a filename and base directory to determine the file location.
  * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
  * at the given name from being referenced.
  *
  * 0 will be returned on success, and a -ve error code if unsuccessful.
  */
 int vfs_statx(int dfd, const char __user *filename, int flags,
 	      struct kstat *stat, u32 request_mask)
 {
 	struct path path;
 	int error = -EINVAL;
 	unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;

 	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
 		       AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
 		return -EINVAL;

 	if (flags & AT_SYMLINK_NOFOLLOW)
 		lookup_flags &= ~LOOKUP_FOLLOW;
 	if (flags & AT_NO_AUTOMOUNT)
 		lookup_flags &= ~LOOKUP_AUTOMOUNT;
 	if (flags & 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, request_mask, flags);
 	path_put(&path);
 	if (retry_estale(error, lookup_flags)) {
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
 	}
 out:
 	return error;
 }
 EXPORT_SYMBOL(vfs_statx);


 #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 */

 static noinline_for_stack int
 cp_statx(const struct kstat *stat, struct statx __user *buffer)
 {
 	struct statx tmp;

 	memset(&tmp, 0, sizeof(tmp));

 	tmp.stx_mask = stat->result_mask;
 	tmp.stx_blksize = stat->blksize;
 	tmp.stx_attributes = stat->attributes;
 	tmp.stx_nlink = stat->nlink;
 	tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
 	tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
 	tmp.stx_mode = stat->mode;
 	tmp.stx_ino = stat->ino;
 	tmp.stx_size = stat->size;
 	tmp.stx_blocks = stat->blocks;
 	tmp.stx_attributes_mask = stat->attributes_mask;
 	tmp.stx_atime.tv_sec = stat->atime.tv_sec;
 	tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
 	tmp.stx_btime.tv_sec = stat->btime.tv_sec;
 	tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
 	tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
 	tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
 	tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
 	tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
 	tmp.stx_rdev_major = MAJOR(stat->rdev);
 	tmp.stx_rdev_minor = MINOR(stat->rdev);
 	tmp.stx_dev_major = MAJOR(stat->dev);
 	tmp.stx_dev_minor = MINOR(stat->dev);

 	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }

 /**
  * sys_statx - System call to get enhanced stats
  * @dfd: Base directory to pathwalk from *or* fd to stat.
  * @filename: File to stat or "" with AT_EMPTY_PATH
  * @flags: AT_* flags to control pathwalk.
  * @mask: Parts of statx struct actually required.
  * @buffer: Result buffer.
  *
  * Note that fstat() can be emulated by setting dfd to the fd of interest,
  * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
  */
 SYSCALL_DEFINE5(statx,
 		int, dfd, const char __user *, filename, unsigned, flags,
 		unsigned int, mask,
 		struct statx __user *, buffer)
 {
 	struct kstat stat;
 	int error;

 	if (mask & STATX__RESERVED)
 		return -EINVAL;
 	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
 		return -EINVAL;

 	error = vfs_statx(dfd, filename, flags, &stat, mask);
 	if (error)
 		return error;

 	return cp_statx(&stat, buffer);
 }

 #ifdef CONFIG_COMPAT
 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
 {
 	struct compat_stat tmp;

 	if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
 		return -EOVERFLOW;

 	memset(&tmp, 0, sizeof(tmp));
 	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 ((u64) stat->size > MAX_NON_LFS)
 		return -EOVERFLOW;
 	tmp.st_size = stat->size;
 	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_blocks = stat->blocks;
 	tmp.st_blksize = stat->blksize;
 	return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }

 COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
 		       struct compat_stat __user *, statbuf)
 {
 	struct kstat stat;
 	int error;

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

 COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 		       struct compat_stat __user *, statbuf)
 {
 	struct kstat stat;
 	int error;

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

 #ifndef __ARCH_WANT_STAT64
 COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
 		       const char __user *, filename,
 		       struct compat_stat __user *, statbuf, int, flag)
 {
 	struct kstat stat;
 	int error;

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

 COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
 		       struct compat_stat __user *, statbuf)
 {
 	struct kstat stat;
 	int error = vfs_fstat(fd, &stat);

 	if (!error)
 		error = cp_compat_stat(&stat, statbuf);
 	return error;
 }
 #endif

 /* 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;
 	}
 }
 EXPORT_SYMBOL(__inode_add_bytes);

 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 = __inode_get_bytes(inode);
 	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);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* 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/compat.h>

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

	/**
	* generic_fillattr - Fill in the basic attributes from the inode struct
	* @inode: Inode to use as the source
	* @stat: Where to fill in the attributes
	*
	* Fill in the basic attributes in the kstat structure from data that's to be
	* found on the VFS inode structure. This is the default if no getattr inode
	* operation is supplied.
	*/
	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;

	if (IS_NOATIME(inode))
	stat->result_mask &= ~STATX_ATIME;
	if (IS_AUTOMOUNT(inode))
	stat->attributes \|= STATX_ATTR_AUTOMOUNT;
	}
	EXPORT_SYMBOL(generic_fillattr);

	/**
	* vfs_getattr_nosec - getattr without security checks
	* @path: file to get attributes from
	* @stat: structure to return attributes in
	* @request_mask: STATX_xxx flags indicating what the caller wants
	* @query_flags: Query mode (KSTAT_QUERY_FLAGS)
	*
	* 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(const struct path path, struct kstat stat,
	u32 request_mask, unsigned int query_flags)
	{
	struct inode *inode = d_backing_inode(path->dentry);

	memset(stat, 0, sizeof(*stat));
	stat->result_mask \|= STATX_BASIC_STATS;
	request_mask &= STATX_ALL;
	query_flags &= KSTAT_QUERY_FLAGS;
	if (inode->i_op->getattr)
	return inode->i_op->getattr(path, stat, request_mask,
	query_flags);

	generic_fillattr(inode, stat);
	return 0;
	}
	EXPORT_SYMBOL(vfs_getattr_nosec);

	/*
	* vfs_getattr - Get the enhanced basic attributes of a file
	* @path: The file of interest
	* @stat: Where to return the statistics
	* @request_mask: STATX_xxx flags indicating what the caller wants
	* @query_flags: Query mode (KSTAT_QUERY_FLAGS)
	*
	* Ask the filesystem for a file's attributes. The caller must indicate in
	* request_mask and query_flags to indicate what they want.
	*
	* If the file is remote, the filesystem can be forced to update the attributes
	* from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
	* suppress the update by passing AT_STATX_DONT_SYNC.
	*
	* Bits must have been set in request_mask to indicate which attributes the
	* caller wants retrieving. Any such attribute not requested may be returned
	* anyway, but the value may be approximate, and, if remote, may not have been
	* synchronised with the server.
	*
	* 0 will be returned on success, and a -ve error code if unsuccessful.
	*/
	int vfs_getattr(const struct path path, struct kstat stat,
	u32 request_mask, unsigned int query_flags)
	{
	int retval;

	retval = security_inode_getattr(path);
	if (retval)
	return retval;
	return vfs_getattr_nosec(path, stat, request_mask, query_flags);
	}
	EXPORT_SYMBOL(vfs_getattr);

	/**
	* vfs_statx_fd - Get the enhanced basic attributes by file descriptor
	* @fd: The file descriptor referring to the file of interest
	* @stat: The result structure to fill in.
	* @request_mask: STATX_xxx flags indicating what the caller wants
	* @query_flags: Query mode (KSTAT_QUERY_FLAGS)
	*
	* This function is a wrapper around vfs_getattr(). The main difference is
	* that it uses a file descriptor to determine the file location.
	*
	* 0 will be returned on success, and a -ve error code if unsuccessful.
	*/
	int vfs_statx_fd(unsigned int fd, struct kstat *stat,
	u32 request_mask, unsigned int query_flags)
	{
	struct fd f;
	int error = -EBADF;

	if (query_flags & ~KSTAT_QUERY_FLAGS)
	return -EINVAL;

	f = fdget_raw(fd);
	if (f.file) {
	error = vfs_getattr(&f.file->f_path, stat,
	request_mask, query_flags);
	fdput(f);
	}
	return error;
	}
	EXPORT_SYMBOL(vfs_statx_fd);

	/**
	* vfs_statx - Get basic and extra attributes by filename
	* @dfd: A file descriptor representing the base dir for a relative filename
	* @filename: The name of the file of interest
	* @flags: Flags to control the query
	* @stat: The result structure to fill in.
	* @request_mask: STATX_xxx flags indicating what the caller wants
	*
	* This function is a wrapper around vfs_getattr(). The main difference is
	* that it uses a filename and base directory to determine the file location.
	* Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
	* at the given name from being referenced.
	*
	* 0 will be returned on success, and a -ve error code if unsuccessful.
	*/
	int vfs_statx(int dfd, const char __user *filename, int flags,
	struct kstat *stat, u32 request_mask)
	{
	struct path path;
	int error = -EINVAL;
	unsigned int lookup_flags = LOOKUP_FOLLOW \| LOOKUP_AUTOMOUNT;

	if ((flags & ~(AT_SYMLINK_NOFOLLOW \| AT_NO_AUTOMOUNT \|
	AT_EMPTY_PATH \| KSTAT_QUERY_FLAGS)) != 0)
	return -EINVAL;

	if (flags & AT_SYMLINK_NOFOLLOW)
	lookup_flags &= ~LOOKUP_FOLLOW;
	if (flags & AT_NO_AUTOMOUNT)
	lookup_flags &= ~LOOKUP_AUTOMOUNT;
	if (flags & 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, request_mask, flags);
	path_put(&path);
	if (retry_estale(error, lookup_flags)) {
	lookup_flags \|= LOOKUP_REVAL;
	goto retry;
	}
	out:
	return error;
	}
	EXPORT_SYMBOL(vfs_statx);


	#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 */

	static noinline_for_stack int
	cp_statx(const struct kstat stat, struct statx __user buffer)
	{
	struct statx tmp;

	memset(&tmp, 0, sizeof(tmp));

	tmp.stx_mask = stat->result_mask;
	tmp.stx_blksize = stat->blksize;
	tmp.stx_attributes = stat->attributes;
	tmp.stx_nlink = stat->nlink;
	tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
	tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
	tmp.stx_mode = stat->mode;
	tmp.stx_ino = stat->ino;
	tmp.stx_size = stat->size;
	tmp.stx_blocks = stat->blocks;
	tmp.stx_attributes_mask = stat->attributes_mask;
	tmp.stx_atime.tv_sec = stat->atime.tv_sec;
	tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
	tmp.stx_btime.tv_sec = stat->btime.tv_sec;
	tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
	tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
	tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
	tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
	tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
	tmp.stx_rdev_major = MAJOR(stat->rdev);
	tmp.stx_rdev_minor = MINOR(stat->rdev);
	tmp.stx_dev_major = MAJOR(stat->dev);
	tmp.stx_dev_minor = MINOR(stat->dev);

	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
	}

	/**
	* sys_statx - System call to get enhanced stats
	* @dfd: Base directory to pathwalk from or fd to stat.
	* @filename: File to stat or "" with AT_EMPTY_PATH
	* @flags: AT_* flags to control pathwalk.
	* @mask: Parts of statx struct actually required.
	* @buffer: Result buffer.
	*
	* Note that fstat() can be emulated by setting dfd to the fd of interest,
	* supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
	*/
	SYSCALL_DEFINE5(statx,
	int, dfd, const char __user *, filename, unsigned, flags,
	unsigned int, mask,
	struct statx __user *, buffer)
	{
	struct kstat stat;
	int error;

	if (mask & STATX__RESERVED)
	return -EINVAL;
	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
	return -EINVAL;

	error = vfs_statx(dfd, filename, flags, &stat, mask);
	if (error)
	return error;

	return cp_statx(&stat, buffer);
	}

	#ifdef CONFIG_COMPAT
	static int cp_compat_stat(struct kstat stat, struct compat_stat __user ubuf)
	{
	struct compat_stat tmp;

	if (!old_valid_dev(stat->dev) \|\| !old_valid_dev(stat->rdev))
	return -EOVERFLOW;

	memset(&tmp, 0, sizeof(tmp));
	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 ((u64) stat->size > MAX_NON_LFS)
	return -EOVERFLOW;
	tmp.st_size = stat->size;
	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_blocks = stat->blocks;
	tmp.st_blksize = stat->blksize;
	return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
	}

	COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
	struct compat_stat __user *, statbuf)
	{
	struct kstat stat;
	int error;

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

	COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
	struct compat_stat __user *, statbuf)
	{
	struct kstat stat;
	int error;

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

	#ifndef __ARCH_WANT_STAT64
	COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
	const char __user *, filename,
	struct compat_stat __user *, statbuf, int, flag)
	{
	struct kstat stat;
	int error;

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

	COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
	struct compat_stat __user *, statbuf)
	{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
	error = cp_compat_stat(&stat, statbuf);
	return error;
	}
	#endif

	/* 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;
	}
	}
	EXPORT_SYMBOL(__inode_add_bytes);

	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 = __inode_get_bytes(inode);
	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);