statx: Add a system call to make enhanced file info available

Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included. The
following have been included:

(1) Make the fields a consistent size on all arches and make them large.

(2) Spare space, request flags and information flags are provided for
future expansion.

(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).

(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).

This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].

(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).

(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].

Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.

(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).

(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].

(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].

(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...

(This requires a separate system call - I have an fsinfo() call idea
for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].

(Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].

(Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).

(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].

(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.

(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.

(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data. This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};

struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};

The defined bits in request_mask and stx_mask are:

STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:

STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

STATX_ATTR_AUTOMOUNT Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

(0) stx_dev_*, stx_blksize.

These are local system information and are always available.

(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.

These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.

If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.

If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.

Note that there are instances where the type might not be valid, for
instance Windows reparse points.

(2) stx_rdev_*.

This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.

(3) stx_btime.

Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

Documentation/filesystems/Locking

···
 	int (*permission) (struct inode *, int, unsigned int);
 	int (*get_acl)(struct inode *, int);
 	int (*setattr) (struct dentry *, struct iattr *);
-	int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *);
+	int (*getattr) (const struct path *, struct dentry *, struct kstat *,
+			u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len);
 	void (*update_time)(struct inode *, struct timespec *, int);

Documentation/filesystems/vfs.txt

···
 	int (*permission) (struct inode *, int);
 	int (*get_acl)(struct inode *, int);
 	int (*setattr) (struct dentry *, struct iattr *);
-	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
+	int (*getattr) (const struct path *, struct dentry *, struct kstat *,
+			u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
 	void (*update_time)(struct inode *, struct timespec *, int);
 	int (*atomic_open)(struct inode *, struct dentry *, struct file *,

arch/x86/entry/syscalls/syscall_32.tbl

···
 380	i386	pkey_mprotect		sys_pkey_mprotect
 381	i386	pkey_alloc		sys_pkey_alloc
 382	i386	pkey_free		sys_pkey_free
+383	i386	statx			sys_statx

arch/x86/entry/syscalls/syscall_64.tbl

···
 329	common	pkey_mprotect		sys_pkey_mprotect
 330	common	pkey_alloc		sys_pkey_alloc
 331	common	pkey_free		sys_pkey_free
+332	common	statx			sys_statx
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact

drivers/base/devtmpfs.c

···
 	if (d_really_is_positive(dentry)) {
 		struct kstat stat;
 		struct path p = {.mnt = parent.mnt, .dentry = dentry};
-		err = vfs_getattr(&p, &stat);
+		err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE,
+				  AT_STATX_SYNC_AS_STAT);
 		if (!err && dev_mynode(dev, d_inode(dentry), &stat)) {
 			struct iattr newattrs;
 			/*

drivers/block/loop.c

···
 
 	if (lo->lo_state != Lo_bound)
 		return -ENXIO;
-	error = vfs_getattr(&file->f_path, &stat);
+	error = vfs_getattr(&file->f_path, &stat,
+			    STATX_INO, AT_STATX_SYNC_AS_STAT);
 	if (error)
 		return error;
 	memset(info, 0, sizeof(*info));

drivers/mtd/ubi/build.c

···
 	if (err)
 		return ERR_PTR(err);
 
-	err = vfs_getattr(&path, &stat);
+	err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
 	path_put(&path);
 	if (err)
 		return ERR_PTR(err);

drivers/mtd/ubi/kapi.c

···
 	if (error)
 		return ERR_PTR(error);
 
-	error = vfs_getattr(&path, &stat);
+	error = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
 	path_put(&path);
 	if (error)
 		return ERR_PTR(error);

drivers/staging/lustre/lustre/llite/file.c

···
 	return rc;
 }
 
-int ll_getattr(struct vfsmount *mnt, struct dentry *de, struct kstat *stat)
+int ll_getattr(const struct path *path, struct kstat *stat,
+	       u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(de);
+	struct inode *inode = d_inode(path->dentry);
 	struct ll_sb_info *sbi = ll_i2sbi(inode);
 	struct ll_inode_info *lli = ll_i2info(inode);
 	int res;
 
-	res = ll_inode_revalidate(de, MDS_INODELOCK_UPDATE |
-				      MDS_INODELOCK_LOOKUP);
+	res = ll_inode_revalidate(path->dentry,
+				  MDS_INODELOCK_UPDATE | MDS_INODELOCK_LOOKUP);
 	ll_stats_ops_tally(sbi, LPROC_LL_GETATTR, 1);
 
 	if (res)

drivers/staging/lustre/lustre/llite/llite_internal.h

···
 int ll_file_release(struct inode *inode, struct file *file);
 int ll_release_openhandle(struct inode *, struct lookup_intent *);
 int ll_md_real_close(struct inode *inode, fmode_t fmode);
-int ll_getattr(struct vfsmount *mnt, struct dentry *de, struct kstat *stat);
+int ll_getattr(const struct path *path, struct kstat *stat,
+	       u32 request_mask, unsigned int flags);
 struct posix_acl *ll_get_acl(struct inode *inode, int type);
 int ll_migrate(struct inode *parent, struct file *file, int mdtidx,
 	       const char *name, int namelen);

fs/9p/vfs_inode.c

···
 
 /**
  * v9fs_vfs_getattr - retrieve file metadata
- * @mnt: mount information
- * @dentry: file to get attributes on
+ * @path: Object to query
  * @stat: metadata structure to populate
+ * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
+ * @flags: AT_STATX_xxx setting
  *
  */
 
 static int
-v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		 struct kstat *stat)
+v9fs_vfs_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	struct p9_wstat *st;

fs/9p/vfs_inode_dotl.c

···
 }
 
 static int
-v9fs_vfs_getattr_dotl(struct vfsmount *mnt, struct dentry *dentry,
-		 struct kstat *stat)
+v9fs_vfs_getattr_dotl(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	struct p9_stat_dotl *st;

fs/afs/inode.c

···
 /*
  * read the attributes of an inode
  */
-int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		      struct kstat *stat)
+int afs_getattr(const struct path *path, struct kstat *stat,
+		u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode;
-
-	inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 
 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
 

fs/afs/internal.h

···
 			      struct afs_callback *);
 extern void afs_zap_data(struct afs_vnode *);
 extern int afs_validate(struct afs_vnode *, struct key *);
-extern int afs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int afs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int afs_setattr(struct dentry *, struct iattr *);
 extern void afs_evict_inode(struct inode *);
 extern int afs_drop_inode(struct inode *);

fs/bad_inode.c

···
 	return -EIO;
 }
 
-static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			struct kstat *stat)
+static int bad_inode_getattr(const struct path *path, struct kstat *stat,
+			     u32 request_mask, unsigned int query_flags)
 {
 	return -EIO;
 }

fs/btrfs/inode.c

···
 	return -ENOMEM;
 }
 
-static int btrfs_getattr(struct vfsmount *mnt,
-			 struct dentry *dentry, struct kstat *stat)
+static int btrfs_getattr(const struct path *path, struct kstat *stat,
+			 u32 request_mask, unsigned int flags)
 {
 	u64 delalloc_bytes;
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	u32 blocksize = inode->i_sb->s_blocksize;
 
 	generic_fillattr(inode, stat);

fs/ceph/inode.c

···
  * Get all attributes.  Hopefully somedata we'll have a statlite()
  * and can limit the fields we require to be accurate.
  */
-int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		 struct kstat *stat)
+int ceph_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	int err;
 

fs/ceph/super.h

···
 extern int ceph_permission(struct inode *inode, int mask);
 extern int __ceph_setattr(struct inode *inode, struct iattr *attr);
 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
-extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			struct kstat *stat);
+extern int ceph_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int flags);
 
 /* xattr.c */
 int __ceph_setxattr(struct inode *, const char *, const void *, size_t, int);

fs/cifs/cifsfs.h

···
 extern int cifs_invalidate_mapping(struct inode *inode);
 extern int cifs_revalidate_mapping(struct inode *inode);
 extern int cifs_zap_mapping(struct inode *inode);
-extern int cifs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int cifs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int cifs_setattr(struct dentry *, struct iattr *);
 
 extern const struct inode_operations cifs_file_inode_ops;

fs/cifs/inode.c

···
 	return cifs_revalidate_mapping(inode);
 }
 
-int cifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		 struct kstat *stat)
+int cifs_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb);
 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 	struct inode *inode = d_inode(dentry);

fs/coda/coda_linux.h

···
 int coda_release(struct inode *i, struct file *f);
 int coda_permission(struct inode *inode, int mask);
 int coda_revalidate_inode(struct inode *);
-int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+int coda_getattr(const struct path *, struct kstat *, u32, unsigned int);
 int coda_setattr(struct dentry *, struct iattr *);
 
 /* this file:  heloers */

fs/coda/inode.c

···
 	coda_cache_clear_inode(inode);
 }
 
-int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int coda_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
-	int err = coda_revalidate_inode(d_inode(dentry));
+	int err = coda_revalidate_inode(d_inode(path->dentry));
 	if (!err)
-		generic_fillattr(d_inode(dentry), stat);
+		generic_fillattr(d_inode(path->dentry), stat);
 	return err;
 }
 

fs/ecryptfs/inode.c

···
 	return rc;
 }
 
-static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
-				 struct kstat *stat)
+static int ecryptfs_getattr_link(const struct path *path, struct kstat *stat,
+				 u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	int rc = 0;
 
···
 	return rc;
 }
 
-static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			    struct kstat *stat)
+static int ecryptfs_getattr(const struct path *path, struct kstat *stat,
+			    u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct kstat lower_stat;
 	int rc;
 
-	rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
+	rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
+			 request_mask, flags);
 	if (!rc) {
 		fsstack_copy_attr_all(d_inode(dentry),
 				      ecryptfs_inode_to_lower(d_inode(dentry)));

fs/exportfs/expfs.c

···
 	 * filesystem supports 64-bit inode numbers.  So we need to
 	 * actually call ->getattr, not just read i_ino:
 	 */
-	error = vfs_getattr_nosec(&child_path, &stat);
+	error = vfs_getattr_nosec(&child_path, &stat,
+				  STATX_INO, AT_STATX_SYNC_AS_STAT);
 	if (error)
 		return error;
 	buffer.ino = stat.ino;

fs/ext4/ext4.h

···
 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
 extern int  ext4_setattr(struct dentry *, struct iattr *);
-extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
-				struct kstat *stat);
+extern int  ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern void ext4_evict_inode(struct inode *);
 extern void ext4_clear_inode(struct inode *);
 extern int  ext4_sync_inode(handle_t *, struct inode *);

fs/ext4/inode.c

···
 	return error;
 }
 
-int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		 struct kstat *stat)
+int ext4_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode;
 	unsigned long long delalloc_blocks;
 
-	inode = d_inode(dentry);
+	inode = d_inode(path->dentry);
 	generic_fillattr(inode, stat);
 
 	/*

fs/f2fs/f2fs.h

···
 void truncate_data_blocks(struct dnode_of_data *dn);
 int truncate_blocks(struct inode *inode, u64 from, bool lock);
 int f2fs_truncate(struct inode *inode);
-int f2fs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			struct kstat *stat);
+int f2fs_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int flags);
 int f2fs_setattr(struct dentry *dentry, struct iattr *attr);
 int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
 int truncate_data_blocks_range(struct dnode_of_data *dn, int count);

fs/f2fs/file.c

···
 	return 0;
 }
 
-int f2fs_getattr(struct vfsmount *mnt,
-			 struct dentry *dentry, struct kstat *stat)
+int f2fs_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	generic_fillattr(inode, stat);
 	stat->blocks <<= 3;
 	return 0;

fs/fat/fat.h

···
 extern const struct inode_operations fat_file_inode_operations;
 extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
-extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		       struct kstat *stat);
+extern int fat_getattr(const struct path *path, struct kstat *stat,
+		       u32 request_mask, unsigned int flags);
 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
 			  int datasync);
 

fs/fat/file.c

···
 	fat_flush_inodes(inode->i_sb, inode, NULL);
 }
 
-int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int fat_getattr(const struct path *path, struct kstat *stat,
+		u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	generic_fillattr(inode, stat);
 	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
 

fs/fuse/dir.c

···
 	return ret;
 }
 
-static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
-			struct kstat *stat)
+static int fuse_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(entry);
+	struct inode *inode = d_inode(path->dentry);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 
 	if (!fuse_allow_current_process(fc))

fs/gfs2/inode.c

···
 
 /**
  * gfs2_getattr - Read out an inode's attributes
- * @mnt: The vfsmount the inode is being accessed from
- * @dentry: The dentry to stat
+ * @path: Object to query
  * @stat: The inode's stats
+ * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
+ * @flags: AT_STATX_xxx setting
  *
  * This may be called from the VFS directly, or from within GFS2 with the
  * inode locked, so we look to see if the glock is already locked and only
···
  * Returns: errno
  */
 
-static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			struct kstat *stat)
+static int gfs2_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
 	int error;

fs/kernfs/inode.c

···
 		set_nlink(inode, kn->dir.subdirs + 2);
 }
 
-int kernfs_iop_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		   struct kstat *stat)
+int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
+		       u32 request_mask, unsigned int query_flags)
 {
-	struct kernfs_node *kn = dentry->d_fsdata;
-	struct inode *inode = d_inode(dentry);
+	struct kernfs_node *kn = path->dentry->d_fsdata;
+	struct inode *inode = d_inode(path->dentry);
 
 	mutex_lock(&kernfs_mutex);
 	kernfs_refresh_inode(kn, inode);

fs/kernfs/kernfs-internal.h

···
 void kernfs_evict_inode(struct inode *inode);
 int kernfs_iop_permission(struct inode *inode, int mask);
 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr);
-int kernfs_iop_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		       struct kstat *stat);
+int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
+		       u32 request_mask, unsigned int query_flags);
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
 
 /*

fs/libfs.c

···
 
 #include "internal.h"
 
-int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		   struct kstat *stat)
+int simple_getattr(const struct path *path, struct kstat *stat,
+		   u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	generic_fillattr(inode, stat);
 	stat->blocks = inode->i_mapping->nrpages << (PAGE_SHIFT - 9);
 	return 0;
···
 	return ERR_PTR(-ENOENT);
 }
 
-static int empty_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
-				 struct kstat *stat)
+static int empty_dir_getattr(const struct path *path, struct kstat *stat,
+			     u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	generic_fillattr(inode, stat);
 	return 0;
 }

fs/minix/inode.c

···
 	return err;
 }
 
-int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int minix_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int flags)
 {
-	struct super_block *sb = dentry->d_sb;
-	generic_fillattr(d_inode(dentry), stat);
-	if (INODE_VERSION(d_inode(dentry)) == MINIX_V1)
+	struct super_block *sb = path->dentry->d_sb;
+	struct inode *inode = d_inode(path->dentry);
+
+	generic_fillattr(inode, stat);
+	if (INODE_VERSION(inode) == MINIX_V1)
 		stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
 	else
 		stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);

fs/minix/minix.h

···
 extern int minix_new_block(struct inode * inode);
 extern void minix_free_block(struct inode *inode, unsigned long block);
 extern unsigned long minix_count_free_blocks(struct super_block *sb);
-extern int minix_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int minix_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 
 extern void V1_minix_truncate(struct inode *);

fs/nfs/inode.c

···
 	return false;
 }
 
-int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int nfs_getattr(const struct path *path, struct kstat *stat,
+		u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
 	int err = 0;
 
···
 	 *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
 	 *    no point in checking those.
 	 */
- 	if ((mnt->mnt_flags & MNT_NOATIME) ||
- 	    ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
+	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
+	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
 		need_atime = 0;
 
 	if (need_atime || nfs_need_revalidate_inode(inode)) {
 		struct nfs_server *server = NFS_SERVER(inode);
 
-		nfs_readdirplus_parent_cache_miss(dentry);
+		nfs_readdirplus_parent_cache_miss(path->dentry);
 		err = __nfs_revalidate_inode(server, inode);
 	} else
-		nfs_readdirplus_parent_cache_hit(dentry);
+		nfs_readdirplus_parent_cache_hit(path->dentry);
 	if (!err) {
 		generic_fillattr(inode, stat);
 		stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));

fs/nfs/namespace.c

···
 }
 
 static int
-nfs_namespace_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+nfs_namespace_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int query_flags)
 {
-	if (NFS_FH(d_inode(dentry))->size != 0)
-		return nfs_getattr(mnt, dentry, stat);
-	generic_fillattr(d_inode(dentry), stat);
+	if (NFS_FH(d_inode(path->dentry))->size != 0)
+		return nfs_getattr(path, stat, request_mask, query_flags);
+	generic_fillattr(d_inode(path->dentry), stat);
 	return 0;
 }
 

fs/nfsd/nfs4xdr.c

···
 		if (path.dentry != path.mnt->mnt_root)
 			break;
 	}
-	err = vfs_getattr(&path, stat);
+	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
 	path_put(&path);
 	return err;
 }
···
 			goto out;
 	}
 
-	err = vfs_getattr(&path, &stat);
+	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
 	if (err)
 		goto out_nfserr;
 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |

fs/nfsd/vfs.h

···
 {
 	struct path p = {.mnt = fh->fh_export->ex_path.mnt,
 			 .dentry = fh->fh_dentry};
-	return nfserrno(vfs_getattr(&p, stat));
+	return nfserrno(vfs_getattr(&p, stat, STATX_BASIC_STATS,
+				    AT_STATX_SYNC_AS_STAT));
 }
 
 static inline int nfsd_create_is_exclusive(int createmode)

fs/ocfs2/file.c

···
 	return status;
 }
 
-int ocfs2_getattr(struct vfsmount *mnt,
-		  struct dentry *dentry,
-		  struct kstat *stat)
+int ocfs2_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int flags)
 {
-	struct inode *inode = d_inode(dentry);
-	struct super_block *sb = dentry->d_sb;
+	struct inode *inode = d_inode(path->dentry);
+	struct super_block *sb = path->dentry->d_sb;
 	struct ocfs2_super *osb = sb->s_fs_info;
 	int err;
 
-	err = ocfs2_inode_revalidate(dentry);
+	err = ocfs2_inode_revalidate(path->dentry);
 	if (err) {
 		if (err != -ENOENT)
 			mlog_errno(err);

fs/ocfs2/file.h

···
 int ocfs2_extend_allocation(struct inode *inode, u32 logical_start,
 		u32 clusters_to_add, int mark_unwritten);
 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);
-int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		  struct kstat *stat);
+int ocfs2_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int flags);
 int ocfs2_permission(struct inode *inode, int mask);
 
 int ocfs2_should_update_atime(struct inode *inode,

fs/orangefs/inode.c

···
 /*
  * Obtain attributes of an object given a dentry
  */
-int orangefs_getattr(struct vfsmount *mnt,
-		  struct dentry *dentry,
-		  struct kstat *kstat)
+int orangefs_getattr(const struct path *path, struct kstat *stat,
+		     u32 request_mask, unsigned int flags)
 {
 	int ret = -ENOENT;
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode = path->dentry->d_inode;
 	struct orangefs_inode_s *orangefs_inode = NULL;
 
 	gossip_debug(GOSSIP_INODE_DEBUG,
 		     "orangefs_getattr: called on %pd\n",
-		     dentry);
+		     path->dentry);
 
 	ret = orangefs_inode_getattr(inode, 0, 0);
 	if (ret == 0) {
-		generic_fillattr(inode, kstat);
+		generic_fillattr(inode, stat);
 
 		/* override block size reported to stat */
 		orangefs_inode = ORANGEFS_I(inode);
-		kstat->blksize = orangefs_inode->blksize;
+		stat->blksize = orangefs_inode->blksize;
 	}
 	return ret;
 }

fs/orangefs/orangefs-kernel.h

···
 
 int orangefs_setattr(struct dentry *dentry, struct iattr *iattr);
 
-int orangefs_getattr(struct vfsmount *mnt,
-		  struct dentry *dentry,
-		  struct kstat *kstat);
+int orangefs_getattr(const struct path *path, struct kstat *stat,
+		     u32 request_mask, unsigned int flags);
 
 int orangefs_permission(struct inode *inode, int mask);
 

fs/overlayfs/copy_up.c

···
 	ovl_path_upper(parent, &parentpath);
 	upperdir = parentpath.dentry;
 
-	err = vfs_getattr(&parentpath, &pstat);
+	err = vfs_getattr(&parentpath, &pstat,
+			  STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);
 	if (err)
 		return err;
 
···
 		}
 
 		ovl_path_lower(next, &lowerpath);
-		err = vfs_getattr(&lowerpath, &stat);
+		err = vfs_getattr(&lowerpath, &stat,
+				  STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
 		/* maybe truncate regular file. this has no effect on dirs */
 		if (flags & O_TRUNC)
 			stat.size = 0;

fs/overlayfs/dir.c

···
 	return err;
 }
 
-static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			 struct kstat *stat)
+static int ovl_dir_getattr(const struct path *path, struct kstat *stat,
+			   u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	int err;
 	enum ovl_path_type type;
 	struct path realpath;
···
 
 	type = ovl_path_real(dentry, &realpath);
 	old_cred = ovl_override_creds(dentry->d_sb);
-	err = vfs_getattr(&realpath, stat);
+	err = vfs_getattr(&realpath, stat, request_mask, flags);
 	revert_creds(old_cred);
 	if (err)
 		return err;
···
 		goto out;
 
 	ovl_path_upper(dentry, &upperpath);
-	err = vfs_getattr(&upperpath, &stat);
+	err = vfs_getattr(&upperpath, &stat,
+			  STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
 	if (err)
 		goto out_unlock;
 

fs/overlayfs/inode.c

···
 	return err;
 }
 
-static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			 struct kstat *stat)
+static int ovl_getattr(const struct path *path, struct kstat *stat,
+		       u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct path realpath;
 	const struct cred *old_cred;
 	int err;
 
 	ovl_path_real(dentry, &realpath);
 	old_cred = ovl_override_creds(dentry->d_sb);
-	err = vfs_getattr(&realpath, stat);
+	err = vfs_getattr(&realpath, stat, request_mask, flags);
 	revert_creds(old_cred);
 	return err;
 }

fs/proc/base.c

···
 	return NULL;
 }
 
-int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int pid_getattr(const struct path *path, struct kstat *stat,
+		u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct task_struct *task;
-	struct pid_namespace *pid = dentry->d_sb->s_fs_info;
+	struct pid_namespace *pid = path->dentry->d_sb->s_fs_info;
 
 	generic_fillattr(inode, stat);
 
···
 	return 0;
 }
 
-static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+static int proc_task_getattr(const struct path *path, struct kstat *stat,
+			     u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct task_struct *p = get_proc_task(inode);
 	generic_fillattr(inode, stat);
 

fs/proc/generic.c

···
 	return 0;
 }
 
-static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			struct kstat *stat)
+static int proc_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct proc_dir_entry *de = PDE(inode);
 	if (de && de->nlink)
 		set_nlink(inode, de->nlink);

fs/proc/internal.h

···
  * base.c
  */
 extern const struct dentry_operations pid_dentry_operations;
-extern int pid_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int proc_setattr(struct dentry *, struct iattr *);
 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
 extern int pid_revalidate(struct dentry *, unsigned int);

fs/proc/proc_net.c

···
 	return de;
 }
 
-static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		struct kstat *stat)
+static int proc_tgid_net_getattr(const struct path *path, struct kstat *stat,
+				 u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct net *net;
 
 	net = get_proc_task_net(inode);

fs/proc/proc_sysctl.c

···
 	return 0;
 }
 
-static int proc_sys_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+static int proc_sys_getattr(const struct path *path, struct kstat *stat,
+			    u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct ctl_table_header *head = grab_header(inode);
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
 

fs/proc/root.c

···
 	proc_sys_init();
 }
 
-static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
-)
+static int proc_root_getattr(const struct path *path, struct kstat *stat,
+			     u32 request_mask, unsigned int query_flags)
 {
-	generic_fillattr(d_inode(dentry), stat);
+	generic_fillattr(d_inode(path->dentry), stat);
 	stat->nlink = proc_root.nlink + nr_processes();
 	return 0;
 }

fs/stat.c

···
 #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->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.
+ * filehandle lookup code, which uses only the inode number and returns no
+ * attributes to any user.  Any other code probably wants vfs_getattr.
  */
-int vfs_getattr_nosec(struct path *path, struct kstat *stat)
+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->mnt, path->dentry, stat);
+		return inode->i_op->getattr(path, stat, request_mask,
+					    query_flags);
 
 	generic_fillattr(inode, stat);
 	return 0;
 }
-
 EXPORT_SYMBOL(vfs_getattr_nosec);
 
-int vfs_getattr(struct path *path, struct kstat *stat)
+/*
+ * 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);
+	return vfs_getattr_nosec(path, stat, request_mask, query_flags);
 }
-
 EXPORT_SYMBOL(vfs_getattr);
 
-int vfs_fstat(unsigned int fd, struct kstat *stat)
+/**
+ * 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 = fdget_raw(fd);
 	int error = -EBADF;
 
 	if (f.file) {
-		error = vfs_getattr(&f.file->f_path, stat);
+		error = vfs_getattr(&f.file->f_path, stat,
+				    request_mask, query_flags);
 		fdput(f);
 	}
 	return error;
 }
-EXPORT_SYMBOL(vfs_fstat);
+EXPORT_SYMBOL(vfs_statx_fd);
 
-int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
-		int flag)
+/**
+ * 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.
+ *
+ * The caller must have preset stat->request_mask as for vfs_getattr().  The
+ * flags are also used to load up stat->query_flags.
+ *
+ * 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 = 0;
+	unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
 
-	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
-		      AT_EMPTY_PATH)) != 0)
-		goto out;
+	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
+		       AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
+		return -EINVAL;
 
-	if (!(flag & AT_SYMLINK_NOFOLLOW))
-		lookup_flags |= LOOKUP_FOLLOW;
-	if (flag & AT_EMPTY_PATH)
+	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);
+	error = vfs_getattr(&path, stat, request_mask, flags);
 	path_put(&path);
 	if (retry_estale(error, lookup_flags)) {
 		lookup_flags |= LOOKUP_REVAL;
···
 out:
 	return error;
 }
-EXPORT_SYMBOL(vfs_fstatat);
-
-int vfs_stat(const char __user *name, struct kstat *stat)
-{
-	return vfs_fstatat(AT_FDCWD, name, stat, 0);
-}
-EXPORT_SYMBOL(vfs_stat);
-
-int vfs_lstat(const char __user *name, struct kstat *stat)
-{
-	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
-}
-EXPORT_SYMBOL(vfs_lstat);
+EXPORT_SYMBOL(vfs_statx);
 
 
 #ifdef __ARCH_WANT_OLD_STAT
···
 {
 	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",
···
 #if BITS_PER_LONG == 32
 	if (stat->size > MAX_NON_LFS)
 		return -EOVERFLOW;
-#endif	
+#endif
 	tmp.st_size = stat->size;
 	tmp.st_atime = stat->atime.tv_sec;
 	tmp.st_mtime = stat->mtime.tv_sec;
···
 	return cp_new_stat64(&stat, statbuf);
 }
 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
+
+static inline int __put_timestamp(struct timespec *kts,
+				  struct statx_timestamp __user *uts)
+{
+	return (__put_user(kts->tv_sec,		&uts->tv_sec		) ||
+		__put_user(kts->tv_nsec,	&uts->tv_nsec		) ||
+		__put_user(0,			&uts->__reserved	));
+}
+
+/*
+ * Set the statx results.
+ */
+static long statx_set_result(struct kstat *stat, struct statx __user *buffer)
+{
+	uid_t uid = from_kuid_munged(current_user_ns(), stat->uid);
+	gid_t gid = from_kgid_munged(current_user_ns(), stat->gid);
+
+	if (__put_user(stat->result_mask,	&buffer->stx_mask	) ||
+	    __put_user(stat->mode,		&buffer->stx_mode	) ||
+	    __clear_user(&buffer->__spare0, sizeof(buffer->__spare0))	  ||
+	    __put_user(stat->nlink,		&buffer->stx_nlink	) ||
+	    __put_user(uid,			&buffer->stx_uid	) ||
+	    __put_user(gid,			&buffer->stx_gid	) ||
+	    __put_user(stat->attributes,	&buffer->stx_attributes	) ||
+	    __put_user(stat->blksize,		&buffer->stx_blksize	) ||
+	    __put_user(MAJOR(stat->rdev),	&buffer->stx_rdev_major	) ||
+	    __put_user(MINOR(stat->rdev),	&buffer->stx_rdev_minor	) ||
+	    __put_user(MAJOR(stat->dev),	&buffer->stx_dev_major	) ||
+	    __put_user(MINOR(stat->dev),	&buffer->stx_dev_minor	) ||
+	    __put_timestamp(&stat->atime,	&buffer->stx_atime	) ||
+	    __put_timestamp(&stat->btime,	&buffer->stx_btime	) ||
+	    __put_timestamp(&stat->ctime,	&buffer->stx_ctime	) ||
+	    __put_timestamp(&stat->mtime,	&buffer->stx_mtime	) ||
+	    __put_user(stat->ino,		&buffer->stx_ino	) ||
+	    __put_user(stat->size,		&buffer->stx_size	) ||
+	    __put_user(stat->blocks,		&buffer->stx_blocks	) ||
+	    __clear_user(&buffer->__spare1, sizeof(buffer->__spare1))	  ||
+	    __clear_user(&buffer->__spare2, sizeof(buffer->__spare2)))
+		return -EFAULT;
+
+	return 0;
+}
+
+/**
+ * sys_statx - System call to get enhanced stats
+ * @dfd: Base directory to pathwalk from *or* fd to stat.
+ * @filename: File to stat *or* NULL.
+ * @flags: AT_* flags to control pathwalk.
+ * @mask: Parts of statx struct actually required.
+ * @buffer: Result buffer.
+ *
+ * Note that if filename is NULL, then it does the equivalent of fstat() using
+ * dfd to indicate the file of interest.
+ */
+SYSCALL_DEFINE5(statx,
+		int, dfd, const char __user *, filename, unsigned, flags,
+		unsigned int, mask,
+		struct statx __user *, buffer)
+{
+	struct kstat stat;
+	int error;
+
+	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, buffer, sizeof(*buffer)))
+		return -EFAULT;
+
+	if (filename)
+		error = vfs_statx(dfd, filename, flags, &stat, mask);
+	else
+		error = vfs_statx_fd(dfd, &stat, mask, flags);
+	if (error)
+		return error;
+	return statx_set_result(&stat, buffer);
+}
 
 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
 void __inode_add_bytes(struct inode *inode, loff_t bytes)

fs/sysv/itree.c

···
 	return blocks;
 }
 
-int sysv_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int sysv_getattr(const struct path *path, struct kstat *stat,
+		 u32 request_mask, unsigned int flags)
 {
-	struct super_block *s = dentry->d_sb;
-	generic_fillattr(d_inode(dentry), stat);
+	struct super_block *s = path->dentry->d_sb;
+	generic_fillattr(d_inode(path->dentry), stat);
 	stat->blocks = (s->s_blocksize / 512) * sysv_nblocks(s, stat->size);
 	stat->blksize = s->s_blocksize;
 	return 0;

fs/sysv/sysv.h

···
 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 extern int sysv_sync_inode(struct inode *);
 extern void sysv_set_inode(struct inode *, dev_t);
-extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int sysv_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int sysv_init_icache(void);
 extern void sysv_destroy_icache(void);
 

fs/ubifs/dir.c

···
 	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
 }
 
-int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		  struct kstat *stat)
+int ubifs_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int flags)
 {
 	loff_t size;
-	struct inode *inode = d_inode(dentry);
+	struct inode *inode = d_inode(path->dentry);
 	struct ubifs_inode *ui = ubifs_inode(inode);
 
 	mutex_lock(&ui->ui_mutex);

fs/ubifs/ubifs.h

···
 /* dir.c */
 struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
 			      umode_t mode);
-int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
-		  struct kstat *stat);
+int ubifs_getattr(const struct path *path, struct kstat *stat,
+		  u32 request_mask, unsigned int flags);
 int ubifs_check_dir_empty(struct inode *dir);
 
 /* xattr.c */

fs/udf/symlink.c

···
 	return err;
 }
 
-static int udf_symlink_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			       struct kstat *stat)
+static int udf_symlink_getattr(const struct path *path, struct kstat *stat,
+				u32 request_mask, unsigned int flags)
 {
+	struct dentry *dentry = path->dentry;
 	struct inode *inode = d_backing_inode(dentry);
 	struct page *page;
 

fs/xfs/xfs_iops.c

···
 
 STATIC int
 xfs_vn_getattr(
-	struct vfsmount		*mnt,
-	struct dentry		*dentry,
-	struct kstat		*stat)
+	const struct path	*path,
+	struct kstat		*stat,
+	u32			request_mask,
+	unsigned int		query_flags)
 {
-	struct inode		*inode = d_inode(dentry);
+	struct inode		*inode = d_inode(path->dentry);
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 

include/linux/fs.h

···
 	int (*rename) (struct inode *, struct dentry *,
 			struct inode *, struct dentry *, unsigned int);
 	int (*setattr) (struct dentry *, struct iattr *);
-	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
+	int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
 		      u64 len);
···
 extern const struct inode_operations page_symlink_inode_operations;
 extern void kfree_link(void *);
 extern void generic_fillattr(struct inode *, struct kstat *);
-int vfs_getattr_nosec(struct path *path, struct kstat *stat);
-extern int vfs_getattr(struct path *, struct kstat *);
+extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
+extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 void __inode_add_bytes(struct inode *inode, loff_t bytes);
 void inode_add_bytes(struct inode *inode, loff_t bytes);
 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
···
 
 extern int iterate_dir(struct file *, struct dir_context *);
 
-extern int vfs_stat(const char __user *, struct kstat *);
-extern int vfs_lstat(const char __user *, struct kstat *);
-extern int vfs_fstat(unsigned int, struct kstat *);
-extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
+extern int vfs_statx(int, const char __user *, int, struct kstat *, u32);
+extern int vfs_statx_fd(unsigned int, struct kstat *, u32, unsigned int);
+
+static inline int vfs_stat(const char __user *filename, struct kstat *stat)
+{
+	return vfs_statx(AT_FDCWD, filename, 0, stat, STATX_BASIC_STATS);
+}
+static inline int vfs_lstat(const char __user *name, struct kstat *stat)
+{
+	return vfs_statx(AT_FDCWD, name, AT_SYMLINK_NOFOLLOW,
+			 stat, STATX_BASIC_STATS);
+}
+static inline int vfs_fstatat(int dfd, const char __user *filename,
+			      struct kstat *stat, int flags)
+{
+	return vfs_statx(dfd, filename, flags, stat, STATX_BASIC_STATS);
+}
+static inline int vfs_fstat(int fd, struct kstat *stat)
+{
+	return vfs_statx_fd(fd, stat, STATX_BASIC_STATS, 0);
+}
+
+
 extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
 extern int vfs_readlink(struct dentry *, char __user *, int);
 
···
 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
 extern int dcache_readdir(struct file *, struct dir_context *);
 extern int simple_setattr(struct dentry *, struct iattr *);
-extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int simple_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern int simple_statfs(struct dentry *, struct kstatfs *);
 extern int simple_open(struct inode *inode, struct file *file);
 extern int simple_link(struct dentry *, struct inode *, struct dentry *);

include/linux/nfs_fs.h

···
 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
-extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int nfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
 extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
 extern int nfs_permission(struct inode *, int);

include/linux/stat.h

···
 #include <linux/time.h>
 #include <linux/uidgid.h>
 
+#define KSTAT_QUERY_FLAGS (AT_STATX_SYNC_TYPE)
+
 struct kstat {
-	u64		ino;
-	dev_t		dev;
+	u32		result_mask;	/* What fields the user got */
 	umode_t		mode;
 	unsigned int	nlink;
+	uint32_t	blksize;	/* Preferred I/O size */
+	u64		attributes;
+#define KSTAT_ATTR_FS_IOC_FLAGS				\
+	(STATX_ATTR_COMPRESSED |			\
+	 STATX_ATTR_IMMUTABLE |				\
+	 STATX_ATTR_APPEND |				\
+	 STATX_ATTR_NODUMP |				\
+	 STATX_ATTR_ENCRYPTED				\
+	 )/* Attrs corresponding to FS_*_FL flags */
+	u64		ino;
+	dev_t		dev;
+	dev_t		rdev;
 	kuid_t		uid;
 	kgid_t		gid;
-	dev_t		rdev;
 	loff_t		size;
-	struct timespec  atime;
+	struct timespec	atime;
 	struct timespec	mtime;
 	struct timespec	ctime;
-	unsigned long	blksize;
-	unsigned long long	blocks;
+	struct timespec	btime;			/* File creation time */
+	u64		blocks;
 };
 
 #endif

include/linux/syscalls.h

···
 struct stat64;
 struct statfs;
 struct statfs64;
+struct statx;
 struct __sysctl_args;
 struct sysinfo;
 struct timespec;
···
 				  unsigned long prot, int pkey);
 asmlinkage long sys_pkey_alloc(unsigned long flags, unsigned long init_val);
 asmlinkage long sys_pkey_free(int pkey);
+asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags,
+			  unsigned mask, struct statx __user *buffer);
 
 #endif

include/uapi/linux/fcntl.h

···
 #define AT_NO_AUTOMOUNT		0x800	/* Suppress terminal automount traversal */
 #define AT_EMPTY_PATH		0x1000	/* Allow empty relative pathname */
 
+#define AT_STATX_SYNC_TYPE	0x6000	/* Type of synchronisation required from statx() */
+#define AT_STATX_SYNC_AS_STAT	0x0000	/* - Do whatever stat() does */
+#define AT_STATX_FORCE_SYNC	0x2000	/* - Force the attributes to be sync'd with the server */
+#define AT_STATX_DONT_SYNC	0x4000	/* - Don't sync attributes with the server */
+
 
 #endif /* _UAPI_LINUX_FCNTL_H */

include/uapi/linux/stat.h

···
 #ifndef _UAPI_LINUX_STAT_H
 #define _UAPI_LINUX_STAT_H
 
+#include <linux/types.h>
 
 #if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2)
 
···
 #define S_IXOTH 00001
 
 #endif
+
+/*
+ * Timestamp structure for the timestamps in struct statx.
+ *
+ * tv_sec holds the number of seconds before (negative) or after (positive)
+ * 00:00:00 1st January 1970 UTC.
+ *
+ * tv_nsec holds a number of nanoseconds before (0..-999,999,999 if tv_sec is
+ * negative) or after (0..999,999,999 if tv_sec is positive) the tv_sec time.
+ *
+ * Note that if both tv_sec and tv_nsec are non-zero, then the two values must
+ * either be both positive or both negative.
+ *
+ * __reserved is held in case we need a yet finer resolution.
+ */
+struct statx_timestamp {
+	__s64	tv_sec;
+	__s32	tv_nsec;
+	__s32	__reserved;
+};
+
+/*
+ * Structures for the extended file attribute retrieval system call
+ * (statx()).
+ *
+ * The caller passes a mask of what they're specifically interested in as a
+ * parameter to statx().  What statx() actually got will be indicated in
+ * st_mask upon return.
+ *
+ * For each bit in the mask argument:
+ *
+ * - if the datum is not supported:
+ *
+ *   - the bit will be cleared, and
+ *
+ *   - the datum will be set to an appropriate fabricated value if one is
+ *     available (eg. CIFS can take a default uid and gid), otherwise
+ *
+ *   - the field will be cleared;
+ *
+ * - otherwise, if explicitly requested:
+ *
+ *   - the datum will be synchronised to the server if AT_STATX_FORCE_SYNC is
+ *     set or if the datum is considered out of date, and
+ *
+ *   - the field will be filled in and the bit will be set;
+ *
+ * - otherwise, if not requested, but available in approximate form without any
+ *   effort, it will be filled in anyway, and the bit will be set upon return
+ *   (it might not be up to date, however, and no attempt will be made to
+ *   synchronise the internal state first);
+ *
+ * - otherwise the field and the bit will be cleared before returning.
+ *
+ * Items in STATX_BASIC_STATS may be marked unavailable on return, but they
+ * will have values installed for compatibility purposes so that stat() and
+ * co. can be emulated in userspace.
+ */
+struct statx {
+	/* 0x00 */
+	__u32	stx_mask;	/* What results were written [uncond] */
+	__u32	stx_blksize;	/* Preferred general I/O size [uncond] */
+	__u64	stx_attributes;	/* Flags conveying information about the file [uncond] */
+	/* 0x10 */
+	__u32	stx_nlink;	/* Number of hard links */
+	__u32	stx_uid;	/* User ID of owner */
+	__u32	stx_gid;	/* Group ID of owner */
+	__u16	stx_mode;	/* File mode */
+	__u16	__spare0[1];
+	/* 0x20 */
+	__u64	stx_ino;	/* Inode number */
+	__u64	stx_size;	/* File size */
+	__u64	stx_blocks;	/* Number of 512-byte blocks allocated */
+	__u64	__spare1[1];
+	/* 0x40 */
+	struct statx_timestamp	stx_atime;	/* Last access time */
+	struct statx_timestamp	stx_btime;	/* File creation time */
+	struct statx_timestamp	stx_ctime;	/* Last attribute change time */
+	struct statx_timestamp	stx_mtime;	/* Last data modification time */
+	/* 0x80 */
+	__u32	stx_rdev_major;	/* Device ID of special file [if bdev/cdev] */
+	__u32	stx_rdev_minor;
+	__u32	stx_dev_major;	/* ID of device containing file [uncond] */
+	__u32	stx_dev_minor;
+	/* 0x90 */
+	__u64	__spare2[14];	/* Spare space for future expansion */
+	/* 0x100 */
+};
+
+/*
+ * Flags to be stx_mask
+ *
+ * Query request/result mask for statx() and struct statx::stx_mask.
+ *
+ * These bits should be set in the mask argument of statx() to request
+ * particular items when calling statx().
+ */
+#define STATX_TYPE		0x00000001U	/* Want/got stx_mode & S_IFMT */
+#define STATX_MODE		0x00000002U	/* Want/got stx_mode & ~S_IFMT */
+#define STATX_NLINK		0x00000004U	/* Want/got stx_nlink */
+#define STATX_UID		0x00000008U	/* Want/got stx_uid */
+#define STATX_GID		0x00000010U	/* Want/got stx_gid */
+#define STATX_ATIME		0x00000020U	/* Want/got stx_atime */
+#define STATX_MTIME		0x00000040U	/* Want/got stx_mtime */
+#define STATX_CTIME		0x00000080U	/* Want/got stx_ctime */
+#define STATX_INO		0x00000100U	/* Want/got stx_ino */
+#define STATX_SIZE		0x00000200U	/* Want/got stx_size */
+#define STATX_BLOCKS		0x00000400U	/* Want/got stx_blocks */
+#define STATX_BASIC_STATS	0x000007ffU	/* The stuff in the normal stat struct */
+#define STATX_BTIME		0x00000800U	/* Want/got stx_btime */
+#define STATX_ALL		0x00000fffU	/* All currently supported flags */
+
+/*
+ * Attributes to be found in stx_attributes
+ *
+ * These give information about the features or the state of a file that might
+ * be of use to ordinary userspace programs such as GUIs or ls rather than
+ * specialised tools.
+ *
+ * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS
+ * semantically.  Where possible, the numerical value is picked to correspond
+ * also.
+ */
+#define STATX_ATTR_COMPRESSED		0x00000004 /* [I] File is compressed by the fs */
+#define STATX_ATTR_IMMUTABLE		0x00000010 /* [I] File is marked immutable */
+#define STATX_ATTR_APPEND		0x00000020 /* [I] File is append-only */
+#define STATX_ATTR_NODUMP		0x00000040 /* [I] File is not to be dumped */
+#define STATX_ATTR_ENCRYPTED		0x00000800 /* [I] File requires key to decrypt in fs */
+
+#define STATX_ATTR_AUTOMOUNT		0x00001000 /* Dir: Automount trigger */
 
 
 #endif /* _UAPI_LINUX_STAT_H */

mm/shmem.c

···
 }
 EXPORT_SYMBOL_GPL(shmem_truncate_range);
 
-static int shmem_getattr(struct vfsmount *mnt, struct dentry *dentry,
-			 struct kstat *stat)
+static int shmem_getattr(const struct path *path, struct kstat *stat,
+			 u32 request_mask, unsigned int query_flags)
 {
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode = path->dentry->d_inode;
 	struct shmem_inode_info *info = SHMEM_I(inode);
 
 	if (info->alloced - info->swapped != inode->i_mapping->nrpages) {

samples/Kconfig

···
 	  Build a virtual tty sample driver for use as a VFIO
 	  mediated device
 
+config SAMPLE_STATX
+	bool "Build example extended-stat using code"
+	depends on BROKEN
+	help
+	  Build example userspace program to use the new extended-stat syscall.
+
 endif # SAMPLES

samples/Makefile

···
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ trace_events/ livepatch/ \
 			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
 			   configfs/ connector/ v4l/ trace_printk/ blackfin/ \
-			   vfio-mdev/
+			   vfio-mdev/ statx/

samples/statx/Makefile

···
+# kbuild trick to avoid linker error. Can be omitted if a module is built.
+obj- := dummy.o
+
+# List of programs to build
+hostprogs-$(CONFIG_SAMPLE_STATX) := test-statx
+
+# Tell kbuild to always build the programs
+always := $(hostprogs-y)
+
+HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include

samples/statx/test-statx.c

···
+/* Test the statx() system call.
+ *
+ * Note that the output of this program is intended to look like the output of
+ * /bin/stat where possible.
+ *
+ * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([e-mail])
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define _GNU_SOURCE
+#define _ATFILE_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <sys/stat.h>
+
+#define AT_STATX_SYNC_TYPE	0x6000
+#define AT_STATX_SYNC_AS_STAT	0x0000
+#define AT_STATX_FORCE_SYNC	0x2000
+#define AT_STATX_DONT_SYNC	0x4000
+
+static __attribute__((unused))
+ssize_t statx(int dfd, const char *filename, unsigned flags,
+	      unsigned int mask, struct statx *buffer)
+{
+	return syscall(__NR_statx, dfd, filename, flags, mask, buffer);
+}
+
+static void print_time(const char *field, struct statx_timestamp *ts)
+{
+	struct tm tm;
+	time_t tim;
+	char buffer[100];
+	int len;
+
+	tim = ts->tv_sec;
+	if (!localtime_r(&tim, &tm)) {
+		perror("localtime_r");
+		exit(1);
+	}
+	len = strftime(buffer, 100, "%F %T", &tm);
+	if (len == 0) {
+		perror("strftime");
+		exit(1);
+	}
+	printf("%s", field);
+	fwrite(buffer, 1, len, stdout);
+	printf(".%09u", ts->tv_nsec);
+	len = strftime(buffer, 100, "%z", &tm);
+	if (len == 0) {
+		perror("strftime2");
+		exit(1);
+	}
+	fwrite(buffer, 1, len, stdout);
+	printf("\n");
+}
+
+static void dump_statx(struct statx *stx)
+{
+	char buffer[256], ft = '?';
+
+	printf("results=%x\n", stx->stx_mask);
+
+	printf(" ");
+	if (stx->stx_mask & STATX_SIZE)
+		printf(" Size: %-15llu", (unsigned long long)stx->stx_size);
+	if (stx->stx_mask & STATX_BLOCKS)
+		printf(" Blocks: %-10llu", (unsigned long long)stx->stx_blocks);
+	printf(" IO Block: %-6llu", (unsigned long long)stx->stx_blksize);
+	if (stx->stx_mask & STATX_TYPE) {
+		switch (stx->stx_mode & S_IFMT) {
+		case S_IFIFO:	printf("  FIFO\n");			ft = 'p'; break;
+		case S_IFCHR:	printf("  character special file\n");	ft = 'c'; break;
+		case S_IFDIR:	printf("  directory\n");		ft = 'd'; break;
+		case S_IFBLK:	printf("  block special file\n");	ft = 'b'; break;
+		case S_IFREG:	printf("  regular file\n");		ft = '-'; break;
+		case S_IFLNK:	printf("  symbolic link\n");		ft = 'l'; break;
+		case S_IFSOCK:	printf("  socket\n");			ft = 's'; break;
+		default:
+			printf(" unknown type (%o)\n", stx->stx_mode & S_IFMT);
+			break;
+		}
+	} else {
+		printf(" no type\n");
+	}
+
+	sprintf(buffer, "%02x:%02x", stx->stx_dev_major, stx->stx_dev_minor);
+	printf("Device: %-15s", buffer);
+	if (stx->stx_mask & STATX_INO)
+		printf(" Inode: %-11llu", (unsigned long long) stx->stx_ino);
+	if (stx->stx_mask & STATX_NLINK)
+		printf(" Links: %-5u", stx->stx_nlink);
+	if (stx->stx_mask & STATX_TYPE) {
+		switch (stx->stx_mode & S_IFMT) {
+		case S_IFBLK:
+		case S_IFCHR:
+			printf(" Device type: %u,%u",
+			       stx->stx_rdev_major, stx->stx_rdev_minor);
+			break;
+		}
+	}
+	printf("\n");
+
+	if (stx->stx_mask & STATX_MODE)
+		printf("Access: (%04o/%c%c%c%c%c%c%c%c%c%c)  ",
+		       stx->stx_mode & 07777,
+		       ft,
+		       stx->stx_mode & S_IRUSR ? 'r' : '-',
+		       stx->stx_mode & S_IWUSR ? 'w' : '-',
+		       stx->stx_mode & S_IXUSR ? 'x' : '-',
+		       stx->stx_mode & S_IRGRP ? 'r' : '-',
+		       stx->stx_mode & S_IWGRP ? 'w' : '-',
+		       stx->stx_mode & S_IXGRP ? 'x' : '-',
+		       stx->stx_mode & S_IROTH ? 'r' : '-',
+		       stx->stx_mode & S_IWOTH ? 'w' : '-',
+		       stx->stx_mode & S_IXOTH ? 'x' : '-');
+	if (stx->stx_mask & STATX_UID)
+		printf("Uid: %5d   ", stx->stx_uid);
+	if (stx->stx_mask & STATX_GID)
+		printf("Gid: %5d\n", stx->stx_gid);
+
+	if (stx->stx_mask & STATX_ATIME)
+		print_time("Access: ", &stx->stx_atime);
+	if (stx->stx_mask & STATX_MTIME)
+		print_time("Modify: ", &stx->stx_mtime);
+	if (stx->stx_mask & STATX_CTIME)
+		print_time("Change: ", &stx->stx_ctime);
+	if (stx->stx_mask & STATX_BTIME)
+		print_time(" Birth: ", &stx->stx_btime);
+
+	if (stx->stx_attributes) {
+		unsigned char bits;
+		int loop, byte;
+
+		static char attr_representation[64 + 1] =
+			/* STATX_ATTR_ flags: */
+			"????????"	/* 63-56 */
+			"????????"	/* 55-48 */
+			"????????"	/* 47-40 */
+			"????????"	/* 39-32 */
+			"????????"	/* 31-24	0x00000000-ff000000 */
+			"????????"	/* 23-16	0x00000000-00ff0000 */
+			"???me???"	/* 15- 8	0x00000000-0000ff00 */
+			"?dai?c??"	/*  7- 0	0x00000000-000000ff */
+			;
+
+		printf("Attributes: %016llx (", stx->stx_attributes);
+		for (byte = 64 - 8; byte >= 0; byte -= 8) {
+			bits = stx->stx_attributes >> byte;
+			for (loop = 7; loop >= 0; loop--) {
+				int bit = byte + loop;
+
+				if (bits & 0x80)
+					putchar(attr_representation[63 - bit]);
+				else
+					putchar('-');
+				bits <<= 1;
+			}
+			if (byte)
+				putchar(' ');
+		}
+		printf(")\n");
+	}
+}
+
+static void dump_hex(unsigned long long *data, int from, int to)
+{
+	unsigned offset, print_offset = 1, col = 0;
+
+	from /= 8;
+	to = (to + 7) / 8;
+
+	for (offset = from; offset < to; offset++) {
+		if (print_offset) {
+			printf("%04x: ", offset * 8);
+			print_offset = 0;
+		}
+		printf("%016llx", data[offset]);
+		col++;
+		if ((col & 3) == 0) {
+			printf("\n");
+			print_offset = 1;
+		} else {
+			printf(" ");
+		}
+	}
+
+	if (!print_offset)
+		printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct statx stx;
+	int ret, raw = 0, atflag = AT_SYMLINK_NOFOLLOW;
+
+	unsigned int mask = STATX_ALL;
+
+	for (argv++; *argv; argv++) {
+		if (strcmp(*argv, "-F") == 0) {
+			atflag &= ~AT_STATX_SYNC_TYPE;
+			atflag |= AT_STATX_FORCE_SYNC;
+			continue;
+		}
+		if (strcmp(*argv, "-D") == 0) {
+			atflag &= ~AT_STATX_SYNC_TYPE;
+			atflag |= AT_STATX_DONT_SYNC;
+			continue;
+		}
+		if (strcmp(*argv, "-L") == 0) {
+			atflag &= ~AT_SYMLINK_NOFOLLOW;
+			continue;
+		}
+		if (strcmp(*argv, "-O") == 0) {
+			mask &= ~STATX_BASIC_STATS;
+			continue;
+		}
+		if (strcmp(*argv, "-A") == 0) {
+			atflag |= AT_NO_AUTOMOUNT;
+			continue;
+		}
+		if (strcmp(*argv, "-R") == 0) {
+			raw = 1;
+			continue;
+		}
+
+		memset(&stx, 0xbf, sizeof(stx));
+		ret = statx(AT_FDCWD, *argv, atflag, mask, &stx);
+		printf("statx(%s) = %d\n", *argv, ret);
+		if (ret < 0) {
+			perror(*argv);
+			exit(1);
+		}
+
+		if (raw)
+			dump_hex((unsigned long long *)&stx, 0, sizeof(stx));
+
+		dump_statx(&stx);
+	}
+	return 0;
+}