text: // 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>
  
  #include "internal.h"
  #include "mount.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;
  }
  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;
  	query_flags &= KSTAT_QUERY_FLAGS;
  
  	/* allow the fs to override these if it really wants to */
  	/* SB_NOATIME means filesystem supplies dummy atime value */
  	if (inode->i_sb->s_flags & SB_NOATIME)
  		stat->result_mask &= ~STATX_ATIME;
  	if (IS_AUTOMOUNT(inode))
  		stat->attributes |= STATX_ATTR_AUTOMOUNT;
  
  	if (IS_DAX(inode))
  		stat->attributes |= STATX_ATTR_DAX;
  
  	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);
  
  static inline unsigned vfs_stat_set_lookup_flags(unsigned *lookup_flags,
  						 int flags)
  {
  	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
  		       AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
  		return -EINVAL;
  
  	*lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
  	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;
  
  	return 0;
  }
  
  /**
   * 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 lookup_flags;
  
  	if (vfs_stat_set_lookup_flags(&lookup_flags, flags))
  		return -EINVAL;
  retry:
  	error = user_path_at(dfd, filename, lookup_flags, &path);
  	if (error)
  		goto out;
  
  	error = vfs_getattr(&path, stat, request_mask, flags);
  	stat->mnt_id = real_mount(path.mnt)->mnt_id;
  	stat->result_mask |= STATX_MNT_ID;
  	if (path.mnt->mnt_root == path.dentry)
  		stat->attributes |= STATX_ATTR_MOUNT_ROOT;
  	stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
  	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 */
  
  #ifdef __ARCH_WANT_NEW_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;
  }
  #endif
  
  static int do_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_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
  		char __user *, buf, int, bufsiz)
  {
  	return do_readlinkat(dfd, pathname, buf, bufsiz);
  }
  
  SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
  		int, bufsiz)
  {
  	return do_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);
  	tmp.stx_mnt_id = stat->mnt_id;
  
  	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
  }
  
  int do_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);
  }
  
  /**
   * 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)
  {
  	return do_statx(dfd, filename, flags, mask, 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);
  