linux-stable/fs/stat.c
Linus Torvalds 96ed320d52 New code for 5.8:
- Clean up io_is_direct.
 - Add a new statx flag to indicate when file data access is being done
   via DAX (as opposed to the page cache).
 - Update the documentation for how system administrators and application
   programmers can take advantage of the (still experimental DAX) feature.
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Merge tag 'vfs-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull DAX updates part one from Darrick Wong:
 "After many years of LKML-wrangling about how to enable programs to
  query and influence the file data access mode (DAX) when a filesystem
  resides on storage devices such as persistent memory, Ira Weiny has
  emerged with a proposed set of standard behaviors that has not been
  shot down by anyone! We're more or less standardizing on the current
  XFS behavior and adapting ext4 to do the same.

  This is the first of a handful pull requests that will make ext4 and
  XFS present a consistent interface for user programs that care about
  DAX. We add a statx attribute that programs can check to see if DAX is
  enabled on a particular file. Then, we update the DAX documentation to
  spell out the user-visible behaviors that filesystems will guarantee
  (until the next storage industry shakeup). The on-disk inode flag has
  been in XFS for a few years now.

  Summary:

   - Clean up io_is_direct.

   - Add a new statx flag to indicate when file data access is being
     done via DAX (as opposed to the page cache).

   - Update the documentation for how system administrators and
     application programmers can take advantage of the (still
     experimental DAX) feature"

Link: https://lore.kernel.org/lkml/20200505002016.1085071-1-ira.weiny@intel.com/

* tag 'vfs-5.8-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  Documentation/dax: Update Usage section
  fs/stat: Define DAX statx attribute
  fs: Remove unneeded IS_DAX() check in io_is_direct()
2020-06-02 19:45:12 -07:00

767 lines
20 KiB
C

// 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);