Re: [PATCH 1/4] statx: Add a system call to make enhanced file info available
From: Andreas Dilger
Date: Thu Nov 17 2016 - 21:48:26 EST
> On Nov 17, 2016, at 11:39 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Thu, 2016-11-17 at 13:35 +0000, David Howells wrote:
>> Add a system call to make extended file information available, including
>> file creation, data version and some attribute flags where available
>> through the underlying filesystem.
>>
>>
>> ========
>> OVERVIEW
>> ========
>>
>> The idea was initially proposed as a set of xattrs that could be retrieved
>> with getxattr(), but the general preferance proved to be for a new syscall
>> with an extended stat structure.
>>
>> This has a number of uses:
>>
>> (1) Better support for the y2038 problem [Arnd Bergmann].
>>
>> (2) 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.
>>
>> This is also specified in NFSv4 as a recommended attribute and could
>> be exported by NFSD [Steve French].
>>
>> (3) 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].
>>
>> (4) Heavyweight stat: Force a netfs to go to the server, even if it thinks
>> its cached attributes are up to date [Trond Myklebust].
>>
>> (5) 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.
>>
>> (6) 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].
>>
>> (7) 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
>>
>> (8) Extra coherency data may be useful in making backups [Andreas Dilger].
>>
>> (9) 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...
>>
>> (10) Make the fields a consistent size on all arches and make them large.
>>
>> (11) Store a 16-byte volume ID in the superblock that can be returned in
>> struct xstat [Steve French].
>>
>> (12) Include granularity fields in the time data to indicate the
>> granularity of each of the times (NFSv4 time_delta) [Steve French].
>>
>> (13) 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).
>>
>> (14) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
>> Michael Kerrisk].
>>
>> (15) Spare space, request flags and information flags are provided for
>> future expansion.
>>
>> Note that not all of the above are implemented here.
>>
>>
>> ===============
>> 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. 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.
>>
>> AT_STATX_FORCE_SYNC can be set in flags. This will require a network
>> filesystem to synchronise its attributes with the server.
>>
>> AT_STATX_DONT_SYNC can be set in flags. This will suppress synchronisation
>> with the server in a network filesystem. The resulting values should be
>> considered approximate.
>>
>> If neither AT_STATX_*_SYNC flag is set, the behaviour is the default for
>> stat() on that filesystem.
>>
>
> We also need to specify here what happens if both bits are set. Should
> that be -EINVAL?
If that is the case, then it doesn't make sense to have two contradictory
flags.
Pick a default behaviour (i.e. return what is known on the client), and
if this is 100% accurate (e.g. local filesystem or filesystem with strong
coherency) then it can optionally set the SYNC flag in the returned flags.
If the application needs 100% accurate size info, then it can set the SYNC
flag in the request and the filesystem may need to do extra work to fetch
accurate data from the server.
>> 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 note that asking for
>> more information may entail more 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 {
>> __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 stx_version;
>> __s64 stx_atime;
>> __s64 stx_btime;
>> __s64 stx_ctime;
>> __s64 stx_mtime;
>> __s32 stx_atime_ns;
>> __s32 stx_btime_ns;
>> __s32 stx_ctime_ns;
>> __s32 stx_mtime_ns;
>> __u32 stx_rdev_major;
>> __u32 stx_rdev_minor;
>> __u32 stx_dev_major;
>> __u32 stx_dev_minor;
>> __u64 __spare1[16];
>> };
>>
>> 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_VERSION Want/got stx_version
>> STATX_ALL [All currently available stuff]
>>
>> stx_btime is the file creation time; stx_version is the data version number
>> (i_version); stx_mask is a bitmask indicating the data provided; and
>> __spares*[] are where as-yet undefined fields can be placed.
>>
>> Time fields are split into separate seconds and nanoseconds fields to make
>> packing easier and the granularities can be queried with the filesystem
>> info system call. 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
>>
>> The supported flags are listed by:
>>
>> STATX_ATTR_FS_IOC_FLAGS
>>
>> [Are any other IOC flags of sufficient general interest to be exposed
>> through this interface?]
>>
>> New flags include:
>>
>> STATX_ATTR_NONUNIX_OWNERSHIP File doesn't have Unixy ownership
>> STATX_ATTR_HAS_ACL File has an ACL
>> STATX_ATTR_KERNEL_API File is kernel API (eg: procfs/sysfs)
>> STATX_ATTR_REMOTE File is remote and needs network
>> STATX_ATTR_FABRICATED File was made up by fs
>> STATX_ATTR_AUTOMOUNT Object is an automount trigger
>> STATX_ATTR_UNLISTED_DENTS Dir: Lookup may find files getdents doesn't
>>
>> 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*, stx_version.
>>
>> Similar to (1), except these will be set to 0 if they don'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 FABRICATED and AUTOMOUNT info flags are set.
>> The former because the directory is invented locally as we don't see the
>> underlying dir on the server, the latter because transiting this directory
>> will cause d_automount to be invoked by the VFS.
>>
>> [root@andromeda tmp]# ./samples/statx/test-statx -A /warthog/data
>> statx(/warthog/data) = 0
>> results=17ff
>> Size: 4096 Blocks: 8 IO Block: 1048576 directory
>> Device: 00:26 Inode: 1703937 Links: 124
>> Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
>> Access: 2016-11-10 15:52:11.219935864+0000
>> Modify: 2016-11-10 08:07:32.482314928+0000
>> Change: 2016-11-10 08:07:32.482314928+0000
>> Data version: 58242ac41cbf8ab0h
>> Attributes: 000000000000e000 (-------- -------- -------- -------- -------- -------- mfr----- --------)
>> IO-blocksize: blksize=1048576
>>
>> Secondly, the result of automounting on that directory.
>>
>> [root@andromeda tmp]# ./samples/statx/test-statx /warthog/data
>> statx(/warthog/data) = 0
>> results=17ff
>> Size: 4096 Blocks: 8 IO Block: 1048576 directory
>> Device: 00:27 Inode: 2 Links: 124
>> Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
>> Access: 2016-11-10 15:52:11.219935864+0000
>> Modify: 2016-11-10 08:07:32.482314928+0000
>> Change: 2016-11-10 08:07:32.482314928+0000
>> Data version: 58242ac41cbf8ab0h
>> Attributes: 0000000000002000 (-------- -------- -------- -------- -------- -------- --r----- --------)
>> IO-blocksize: blksize=1048576
>>
>> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
>> ---
>>
>> arch/x86/entry/syscalls/syscall_32.tbl | 1
>> arch/x86/entry/syscalls/syscall_64.tbl | 1
>> fs/exportfs/expfs.c | 4
>> fs/stat.c | 294 +++++++++++++++++++++++++++++---
>> include/linux/fs.h | 5 -
>> include/linux/stat.h | 19 +-
>> include/linux/syscalls.h | 3
>> include/uapi/linux/fcntl.h | 2
>> include/uapi/linux/stat.h | 124 +++++++++++++
>> samples/Kconfig | 5 +
>> samples/Makefile | 3
>> samples/statx/Makefile | 10 +
>> samples/statx/test-statx.c | 248 +++++++++++++++++++++++++++
>> 13 files changed, 679 insertions(+), 40 deletions(-)
>> create mode 100644 samples/statx/Makefile
>> create mode 100644 samples/statx/test-statx.c
>>
>> diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
>> index 2b3618542544..9ba050fe47f3 100644
>> --- a/arch/x86/entry/syscalls/syscall_32.tbl
>> +++ b/arch/x86/entry/syscalls/syscall_32.tbl
>> @@ -389,3 +389,4 @@
>> 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
>> diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
>> index e93ef0b38db8..5aef183e2f85 100644
>> --- a/arch/x86/entry/syscalls/syscall_64.tbl
>> +++ b/arch/x86/entry/syscalls/syscall_64.tbl
>> @@ -338,6 +338,7 @@
>> 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
>> diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
>> index a4b531be9168..2acc31751248 100644
>> --- a/fs/exportfs/expfs.c
>> +++ b/fs/exportfs/expfs.c
>> @@ -299,7 +299,9 @@ static int get_name(const struct path *path, char *name, struct dentry *child)
>> * 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);
>> + stat.query_flags = 0;
>> + stat.request_mask = STATX_BASIC_STATS;
>> + error = vfs_xgetattr_nosec(&child_path, &stat);
>> if (error)
>> return error;
>> buffer.ino = stat.ino;
>> diff --git a/fs/stat.c b/fs/stat.c
>> index bc045c7994e1..78c0a5086038 100644
>> --- a/fs/stat.c
>> +++ b/fs/stat.c
>> @@ -18,6 +18,15 @@
>> #include <asm/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;
>> @@ -27,87 +36,189 @@ void generic_fillattr(struct inode *inode, struct kstat *stat)
>> stat->uid = inode->i_uid;
>> stat->gid = inode->i_gid;
>> stat->rdev = inode->i_rdev;
>> - stat->size = i_size_read(inode);
>> - stat->atime = inode->i_atime;
>> stat->mtime = inode->i_mtime;
>> stat->ctime = inode->i_ctime;
>> - stat->blksize = (1 << inode->i_blkbits);
>> + stat->size = i_size_read(inode);
>> stat->blocks = inode->i_blocks;
>> -}
>> + stat->blksize = 1 << inode->i_blkbits;
>>
>> + stat->result_mask |= STATX_BASIC_STATS;
>> + if (IS_NOATIME(inode))
>> + stat->result_mask &= ~STATX_ATIME;
>> + else
>> + stat->atime = inode->i_atime;
>> +
>> + if (IS_AUTOMOUNT(inode))
>> + stat->attributes |= STATX_ATTR_AUTOMOUNT;
>> +}
>> EXPORT_SYMBOL(generic_fillattr);
>>
>> /**
>> - * vfs_getattr_nosec - getattr without security checks
>> + * vfs_xgetattr_nosec - getattr without security checks
>> * @path: file to get attributes from
>> * @stat: structure to return attributes in
>> *
>> * 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.
>> + * Currently the only caller other than vfs_xgetattr 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_xgetattr.
>> + *
>> + * The caller must set stat->request_mask to indicate what they want and
>> + * stat->query_flags to indicate whether the server should be queried.
>> */
>> -int vfs_getattr_nosec(struct path *path, struct kstat *stat)
>> +int vfs_xgetattr_nosec(struct path *path, struct kstat *stat)
>> {
>> struct inode *inode = d_backing_inode(path->dentry);
>>
>> + stat->query_flags &= ~KSTAT_QUERY_FLAGS;
>> +
>> + stat->result_mask = 0;
>> + stat->attributes = 0;
>> if (inode->i_op->getattr)
>> return inode->i_op->getattr(path->mnt, path->dentry, stat);
>>
>> generic_fillattr(inode, stat);
>> return 0;
>> }
>> +EXPORT_SYMBOL(vfs_xgetattr_nosec);
>>
>> -EXPORT_SYMBOL(vfs_getattr_nosec);
>> -
>> -int vfs_getattr(struct path *path, struct kstat *stat)
>> +/*
>> + * vfs_xgetattr - Get the enhanced basic attributes of a file
>> + * @path: The file of interest
>> + * @stat: Where to return the statistics
>> + *
>> + * Ask the filesystem for a file's attributes. The caller must have preset
>> + * stat->request_mask and stat->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_FORCE_ATTR_SYNC in query_flags or can
>> + * suppress the update by passing AT_NO_ATTR_SYNC.
>> + *
>> + * Bits must have been set in stat->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_xgetattr(struct path *path, struct kstat *stat)
>> {
>> int retval;
>>
>> retval = security_inode_getattr(path);
>> if (retval)
>> return retval;
>> - return vfs_getattr_nosec(path, stat);
>> + return vfs_xgetattr_nosec(path, stat);
>> }
>> +EXPORT_SYMBOL(vfs_xgetattr);
>>
>> +/**
>> + * vfs_getattr - Get the basic attributes of a file
>> + * @path: The file of interest
>> + * @stat: Where to return the statistics
>> + *
>> + * Ask the filesystem for a file's attributes. If remote, the filesystem isn't
>> + * forced to update its files from the backing store. Only the basic set of
>> + * attributes will be retrieved; anyone wanting more must use vfs_xgetattr(),
>> + * as must anyone who wants to force attributes to be sync'd with the server.
>> + *
>> + * 0 will be returned on success, and a -ve error code if unsuccessful.
>> + */
>> +int vfs_getattr(struct path *path, struct kstat *stat)
>> +{
>> + stat->query_flags = 0;
>> + stat->request_mask = STATX_BASIC_STATS;
>> + return vfs_xgetattr(path, stat);
>> +}
>> EXPORT_SYMBOL(vfs_getattr);
>>
>> -int vfs_fstat(unsigned int fd, struct kstat *stat)
>> +/**
>> + * vfs_fstatx - 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.
>> + *
>> + * This function is a wrapper around vfs_xgetattr(). The main difference is
>> + * that it uses a file descriptor to determine the file location.
>> + *
>> + * The caller must have preset stat->query_flags and stat->request_mask as for
>> + * vfs_xgetattr().
>> + *
>> + * 0 will be returned on success, and a -ve error code if unsuccessful.
>> + */
>> +int vfs_fstatx(unsigned int fd, struct kstat *stat)
>> {
>> struct fd f = fdget_raw(fd);
>> int error = -EBADF;
>>
>> if (f.file) {
>> - error = vfs_getattr(&f.file->f_path, stat);
>> + error = vfs_xgetattr(&f.file->f_path, stat);
>> fdput(f);
>> }
>> return error;
>> }
>> +EXPORT_SYMBOL(vfs_fstatx);
>> +
>> +/**
>> + * vfs_fstat - Get 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(unsigned int fd, struct kstat *stat)
>> +{
>> + stat->query_flags = 0;
>> + stat->request_mask = STATX_BASIC_STATS;
>> + return vfs_fstatx(fd, stat);
>> +}
>> EXPORT_SYMBOL(vfs_fstat);
>>
>> -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.
>> + *
>> + * This function is a wrapper around vfs_xgetattr(). The main difference is
>> + * that it uses a filename and base directory to determine the file location.
>> + * Additionally, the addition of AT_SYMLINK_NOFOLLOW to flags will prevent a
>> + * symlink at the given name from being referenced.
>> + *
>> + * The caller must have preset stat->request_mask as for vfs_xgetattr(). 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)
>> {
>> 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;
>> + stat->query_flags = flags;
>> +
>> retry:
>> error = user_path_at(dfd, filename, lookup_flags, &path);
>> if (error)
>> goto out;
>>
>> - error = vfs_getattr(&path, stat);
>> + error = vfs_xgetattr(&path, stat);
>> path_put(&path);
>> if (retry_estale(error, lookup_flags)) {
>> lookup_flags |= LOOKUP_REVAL;
>> @@ -116,17 +227,65 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
>> out:
>> return error;
>> }
>> +EXPORT_SYMBOL(vfs_statx);
>> +
>> +/**
>> + * vfs_fstatat - Get basic 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.
>> + *
>> + * This function is a wrapper around vfs_statx(). The difference is that it
>> + * preselects basic stats only. The flags are used to load up
>> + * stat->query_flags in addition to indicating symlink handling during path
>> + * resolution.
>> + *
>> + * 0 will be returned on success, and a -ve error code if unsuccessful.
>> + */
>> +int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
>> + int flags)
>> +{
>> + stat->request_mask = STATX_BASIC_STATS;
>> + return vfs_statx(dfd, filename, flags, stat);
>> +}
>> EXPORT_SYMBOL(vfs_fstatat);
>>
>> -int vfs_stat(const char __user *name, struct kstat *stat)
>> +/**
>> + * vfs_stat - Get basic attributes by filename
>> + * @filename: The name of the file of interest
>> + * @stat: The result structure to fill in.
>> + *
>> + * This function is a wrapper around vfs_statx(). The difference is that it
>> + * preselects basic stats only, terminal symlinks are followed regardless and a
>> + * remote filesystem can't be forced to query the server. If such is desired,
>> + * vfs_statx() should be used instead.
>> + *
>> + * 0 will be returned on success, and a -ve error code if unsuccessful.
>> + */
>> +int vfs_stat(const char __user *filename, struct kstat *stat)
>> {
>> - return vfs_fstatat(AT_FDCWD, name, stat, 0);
>> + stat->request_mask = STATX_BASIC_STATS;
>> + return vfs_statx(AT_FDCWD, filename, 0, stat);
>> }
>> EXPORT_SYMBOL(vfs_stat);
>>
>> +/**
>> + * vfs_lstat - Get basic attrs by filename, without following terminal symlink
>> + * @filename: The name of the file of interest
>> + * @stat: The result structure to fill in.
>> + *
>> + * This function is a wrapper around vfs_statx(). The difference is that it
>> + * preselects basic stats only, terminal symlinks are note followed regardless
>> + * and a remote filesystem can't be forced to query the server. If such is
>> + * desired, vfs_statx() should be used instead.
>> + *
>> + * 0 will be returned on success, and a -ve error code if unsuccessful.
>> + */
>> int vfs_lstat(const char __user *name, struct kstat *stat)
>> {
>> - return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
>> + stat->request_mask = STATX_BASIC_STATS;
>> + return vfs_statx(AT_FDCWD, name, AT_SYMLINK_NOFOLLOW, stat);
>> }
>> EXPORT_SYMBOL(vfs_lstat);
>>
>> @@ -141,7 +300,7 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta
>> {
>> 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",
>> @@ -166,7 +325,7 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta
>> #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;
>> @@ -443,6 +602,79 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
>> }
>> #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
>>
>> +/*
>> + * 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);
>> +
>> +#define __put_timestamp(kts, uts) ( \
>> + __put_user(kts.tv_sec, uts##_s ) || \
>> + __put_user(kts.tv_nsec, uts##_ns ))
>> +
>> + 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 ) ||
>> + __put_user(stat->version, &buffer->stx_version ) ||
>> + __clear_user(&buffer->__spare1, sizeof(buffer->__spare1)))
>> + 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 (!access_ok(VERIFY_WRITE, buffer, sizeof(*buffer)))
>> + return -EFAULT;
>> +
>> + memset(&stat, 0, sizeof(stat));
>> + stat.query_flags = flags;
>> + stat.request_mask = mask & STATX_ALL;
>> +
>> + if (filename)
>> + error = vfs_statx(dfd, filename, flags, &stat);
>> + else
>> + error = vfs_fstatx(dfd, &stat);
>> + 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)
>> {
>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>> index 16d2b6e874d6..f153199566b4 100644
>> --- a/include/linux/fs.h
>> +++ b/include/linux/fs.h
>> @@ -2916,8 +2916,9 @@ extern const struct inode_operations page_symlink_inode_operations;
>> extern void kfree_link(void *);
>> extern int generic_readlink(struct dentry *, char __user *, int);
>> extern void generic_fillattr(struct inode *, struct kstat *);
>> -int vfs_getattr_nosec(struct path *path, struct kstat *stat);
>> +extern int vfs_xgetattr_nosec(struct path *path, struct kstat *stat);
>> extern int vfs_getattr(struct path *, struct kstat *);
>> +extern int vfs_xgetattr(struct path *, struct kstat *);
>> 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);
>> @@ -2935,6 +2936,8 @@ 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 const char *vfs_get_link(struct dentry *, struct delayed_call *);
>> +extern int vfs_xstat(int, const char __user *, int, struct kstat *);
>> +extern int vfs_xfstat(unsigned int, struct kstat *);
>>
>> extern int __generic_block_fiemap(struct inode *inode,
>> struct fiemap_extent_info *fieinfo,
>> diff --git a/include/linux/stat.h b/include/linux/stat.h
>> index 075cb0c7eb2a..cf25bb5cf754 100644
>> --- a/include/linux/stat.h
>> +++ b/include/linux/stat.h
>> @@ -19,19 +19,26 @@
>> #include <linux/uidgid.h>
>>
>> struct kstat {
>> - u64 ino;
>> - dev_t dev;
>> + u32 query_flags; /* Operational flags */
>> +#define KSTAT_QUERY_FLAGS (AT_STATX_FORCE_SYNC | AT_STATX_DONT_SYNC)
>> + u32 request_mask; /* What fields the user asked for */
>> + u32 result_mask; /* What fields the user got */
>> umode_t mode;
>> unsigned int nlink;
>> + uint32_t blksize; /* Preferred I/O size */
>> + u64 attributes;
>> + 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;
>> + u64 version; /* Data version */
>> };
>>
>> #endif
>> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
>> index 91a740f6b884..980c3c9b06f8 100644
>> --- a/include/linux/syscalls.h
>> +++ b/include/linux/syscalls.h
>> @@ -48,6 +48,7 @@ struct stat;
>> struct stat64;
>> struct statfs;
>> struct statfs64;
>> +struct statx;
>> struct __sysctl_args;
>> struct sysinfo;
>> struct timespec;
>> @@ -902,5 +903,7 @@ asmlinkage long sys_pkey_mprotect(unsigned long start, size_t len,
>> 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
>> diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
>> index beed138bd359..c49cb6edaafa 100644
>> --- a/include/uapi/linux/fcntl.h
>> +++ b/include/uapi/linux/fcntl.h
>> @@ -62,6 +62,8 @@
>> #define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
>> #define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */
>> #define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
>> +#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 */
>> diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
>> index 7fec7e36d921..32ea14c1c960 100644
>> --- a/include/uapi/linux/stat.h
>> +++ b/include/uapi/linux/stat.h
>> @@ -1,6 +1,7 @@
>> #ifndef _UAPI_LINUX_STAT_H
>> #define _UAPI_LINUX_STAT_H
>>
>> +#include <linux/types.h>
>>
>> #if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2)
>>
>> @@ -41,5 +42,128 @@
>>
>> #endif
>>
>> +/*
>> + * 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 stx_version; /* Data version number */
>> + /* 0x40 */
>> + __s64 stx_atime_s; /* Last access time */
>> + __s64 stx_btime_s; /* File creation time */
>> + __s64 stx_ctime_s; /* Last attribute change time */
>> + __s64 stx_mtime_s; /* Last data modification time */
>> + /* 0x60 */
>> + __s32 stx_atime_ns; /* Last access time (ns part) */
>> + __s32 stx_btime_ns; /* File creation time (ns part) */
>> + __s32 stx_ctime_ns; /* Last attribute change time (ns part) */
>> + __s32 stx_mtime_ns; /* Last data modification time (ns part) */
>> + /* 0x70 */
>> + __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;
>> + /* 0x80 */
>> + __u64 __spare1[16]; /* 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_VERSION 0x00001000U /* Want/got stx_version */
>> +#define STATX_ALL 0x00001fffU /* 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_NONUNIX_OWNERSHIP 0x00000100 /* File has non-Unix ownership details */
>> +#define STATX_ATTR_HAS_ACL 0x00000200 /* File has an ACL */
>> +#define STATX_ATTR_ENCRYPTED 0x00000800 /* [I] File requires key to decrypt in fs */
>> +#define STATX_ATTR_FS_IOC_FLAGS 0x00000874 /* Attrs corresponding to FS_*_FL flags */
>> +
>> +#define STATX_ATTR_KERNEL_API 0x00001000 /* File is kernel API (eg: procfs/sysfs) */
>> +#define STATX_ATTR_REMOTE 0x00002000 /* File is remote and needs network */
>> +#define STATX_ATTR_FABRICATED 0x00004000 /* File was made up by fs and is transient */
>> +#define STATX_ATTR_AUTOMOUNT 0x00008000 /* Dir: Automount trigger */
>> +#define STATX_ATTR_UNLISTED_DENTS 0x00010000 /* Dir: Lookup may find files getdents doesn't */
>> +
>>
>> #endif /* _UAPI_LINUX_STAT_H */
>> diff --git a/samples/Kconfig b/samples/Kconfig
>> index a6d2a43bbf2e..94a7488f14ae 100644
>> --- a/samples/Kconfig
>> +++ b/samples/Kconfig
>> @@ -105,4 +105,9 @@ config SAMPLE_BLACKFIN_GPTIMERS
>> help
>> Build samples of blackfin gptimers sample module.
>>
>> +config SAMPLE_STATX
>> + bool "Build example extended-stat using code"
>> + help
>> + Build example userspace program to use the new extended-stat syscall.
>> +
>> endif # SAMPLES
>> diff --git a/samples/Makefile b/samples/Makefile
>> index e17d66d77f09..8eeb15e13413 100644
>> --- a/samples/Makefile
>> +++ b/samples/Makefile
>> @@ -2,4 +2,5 @@
>>
>> obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \
>> hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
>> - configfs/ connector/ v4l/ trace_printk/ blackfin/
>> + configfs/ connector/ v4l/ trace_printk/ blackfin/ \
>> + statx/
>> diff --git a/samples/statx/Makefile b/samples/statx/Makefile
>> new file mode 100644
>> index 000000000000..1f80a3d8cf45
>> --- /dev/null
>> +++ b/samples/statx/Makefile
>> @@ -0,0 +1,10 @@
>> +# kbuild trick to avoid linker error. Can be omitted if a module is built.
>> +obj- := dummy.o
>> +
>> +# List of programs to build
>> +hostprogs-$(CONFIG_SAMPLE_STATX) := test-statx
>> +
>> +# Tell kbuild to always build the programs
>> +always := $(hostprogs-y)
>> +
>> +HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include
>> diff --git a/samples/statx/test-statx.c b/samples/statx/test-statx.c
>> new file mode 100644
>> index 000000000000..2419b33fc15d
>> --- /dev/null
>> +++ b/samples/statx/test-statx.c
>> @@ -0,0 +1,248 @@
>> +/* Test the statx() system call
>> + *
>> + * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
>> + * Written by David Howells (dhowells@xxxxxxxxxx)
>> + *
>> + * 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_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, __s64 tv_sec, __s32 tv_nsec)
>> +{
>> + struct tm tm;
>> + time_t tim;
>> + char buffer[100];
>> + int len;
>> +
>> + tim = 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", 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_MODE) {
>> + 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;
>> + }
>> + }
>> +
>> + 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_SIZE)
>> + printf(" Links: %-5u", stx->stx_nlink);
>> + switch (stx->stx_mask & STATX_MODE) {
>> + 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_s, stx->stx_atime_ns);
>> + if (stx->stx_mask & STATX_MTIME)
>> + print_time("Modify: ", stx->stx_mtime_s, stx->stx_mtime_ns);
>> + if (stx->stx_mask & STATX_CTIME)
>> + print_time("Change: ", stx->stx_ctime_s, stx->stx_ctime_ns);
>> + if (stx->stx_mask & STATX_BTIME)
>> + print_time(" Birth: ", stx->stx_btime_s, stx->stx_btime_ns);
>> +
>> + if (stx->stx_mask & STATX_VERSION)
>> + printf("Data version: %llxh\n",
>> + (unsigned long long)stx->stx_version);
>> +
>> + 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 */
>> + "???????u" /* 23-16 0x00000000-00ff0000 */
>> + "mfrke?AU" /* 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");
>> + }
>> +
>> + printf("IO-blocksize: blksize=%u\n", stx->stx_blksize);
>> +}
>> +
>> +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_FORCE_SYNC;
>> + continue;
>> + }
>> + if (strcmp(*argv, "-D") == 0) {
>> + 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;
>> +}
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Cheers, Andreas
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