Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 827 insertions, 0 deletions

diff --git a/fs/stat.c b/fs/stat.c
new file mode 100644
index 000000000..ef50573c7
--- /dev/null
+++ b/fs/stat.c
@@ -0,0 +1,827 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/stat.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/blkdev.h>
+#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
+ * @mnt_userns:	user namespace of the mount the inode was found from
+ * @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.
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before filling in the
+ * uid and gid filds. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ */
+void generic_fillattr(struct user_namespace *mnt_userns, 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 = i_uid_into_mnt(mnt_userns, inode);
+	stat->gid = i_gid_into_mnt(mnt_userns, inode);
+	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);
+
+/**
+ * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
+ * @inode:	Inode to use as the source
+ * @stat:	Where to fill in the attribute flags
+ *
+ * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
+ * inode that are published on i_flags and enforced by the VFS.
+ */
+void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
+{
+	if (inode->i_flags & S_IMMUTABLE)
+		stat->attributes |= STATX_ATTR_IMMUTABLE;
+	if (inode->i_flags & S_APPEND)
+		stat->attributes |= STATX_ATTR_APPEND;
+	stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
+}
+EXPORT_SYMBOL(generic_fill_statx_attr);
+
+/**
+ * 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 (AT_STATX_SYNC_TYPE)
+ *
+ * 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 user_namespace *mnt_userns;
+	struct inode *inode = d_backing_inode(path->dentry);
+
+	memset(stat, 0, sizeof(*stat));
+	stat->result_mask |= STATX_BASIC_STATS;
+	query_flags &= AT_STATX_SYNC_TYPE;
+
+	/* 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;
+
+	/*
+	 * Note: If you add another clause to set an attribute flag, please
+	 * update attributes_mask below.
+	 */
+	if (IS_AUTOMOUNT(inode))
+		stat->attributes |= STATX_ATTR_AUTOMOUNT;
+
+	if (IS_DAX(inode))
+		stat->attributes |= STATX_ATTR_DAX;
+
+	stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
+				  STATX_ATTR_DAX);
+
+	mnt_userns = mnt_user_ns(path->mnt);
+	if (inode->i_op->getattr)
+		return inode->i_op->getattr(mnt_userns, path, stat,
+					    request_mask, query_flags);
+
+	generic_fillattr(mnt_userns, 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 (AT_STATX_SYNC_TYPE)
+ *
+ * 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_fstat - Get the basic attributes by file descriptor
+ * @fd: The file descriptor referring to the file of interest
+ * @stat: The result structure to fill in.
+ *
+ * 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_fstat(int fd, struct kstat *stat)
+{
+	struct fd f;
+	int error;
+
+	f = fdget_raw(fd);
+	if (!f.file)
+		return -EBADF;
+	error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
+	fdput(f);
+	return error;
+}
+
+int getname_statx_lookup_flags(int flags)
+{
+	int lookup_flags = 0;
+
+	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 lookup_flags;
+}
+
+/**
+ * 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.
+ */
+static int vfs_statx(int dfd, struct filename *filename, int flags,
+	      struct kstat *stat, u32 request_mask)
+{
+	struct path path;
+	unsigned int lookup_flags = getname_statx_lookup_flags(flags);
+	int error;
+
+	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
+		      AT_STATX_SYNC_TYPE))
+		return -EINVAL;
+
+retry:
+	error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
+	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;
+
+	/* Handle STATX_DIOALIGN for block devices. */
+	if (request_mask & STATX_DIOALIGN) {
+		struct inode *inode = d_backing_inode(path.dentry);
+
+		if (S_ISBLK(inode->i_mode))
+			bdev_statx_dioalign(inode, stat);
+	}
+
+	path_put(&path);
+	if (retry_estale(error, lookup_flags)) {
+		lookup_flags |= LOOKUP_REVAL;
+		goto retry;
+	}
+out:
+	return error;
+}
+
+int vfs_fstatat(int dfd, const char __user *filename,
+			      struct kstat *stat, int flags)
+{
+	int ret;
+	int statx_flags = flags | AT_NO_AUTOMOUNT;
+	struct filename *name;
+
+	name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);
+	ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
+	putname(name);
+
+	return ret;
+}
+
+#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
+
+#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 (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
+		return -EOVERFLOW;
+	if (sizeof(tmp.st_rdev) < 4 && !old_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 = new_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 = new_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;
+	tmp.stx_dio_mem_align = stat->dio_mem_align;
+	tmp.stx_dio_offset_align = stat->dio_offset_align;
+
+	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+int do_statx(int dfd, struct filename *filename, unsigned int 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)
+{
+	int ret;
+	struct filename *name;
+
+	name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);
+	ret = do_statx(dfd, name, flags, mask, buffer);
+	putname(name);
+
+	return ret;
+}
+
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
+static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
+{
+	struct compat_stat tmp;
+
+	if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
+		return -EOVERFLOW;
+	if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
+		return -EOVERFLOW;
+
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.st_dev = new_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 = new_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);