Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941649AbcKQSjf (ORCPT ); Thu, 17 Nov 2016 13:39:35 -0500 Received: from mail-yb0-f181.google.com ([209.85.213.181]:33694 "EHLO mail-yb0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941480AbcKQSjb (ORCPT ); Thu, 17 Nov 2016 13:39:31 -0500 Message-ID: <1479407964.4556.5.camel@redhat.com> Subject: Re: [PATCH 1/4] statx: Add a system call to make enhanced file info available From: Jeff Layton To: David Howells , linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Date: Thu, 17 Nov 2016 13:39:24 -0500 In-Reply-To: <147938970382.13574.11581172952175034619.stgit@warthog.procyon.org.uk> References: <147938969703.13574.10295364502230379833.stgit@warthog.procyon.org.uk> <147938970382.13574.11581172952175034619.stgit@warthog.procyon.org.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.1 (3.22.1-2.fc25) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 47196 Lines: 1289 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? > 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 > --- > > 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 > #include > > +/** > + * 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 > > 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 > > #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@redhat.com) > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#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@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jeff Layton