Re: [PATCH 2/2 V2] xfs_io: hook up statx

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Mar 23, 2017 at 11:45:45PM -0500, Eric Sandeen wrote:
> Wire up the statx syscall to xfs_io.
> 
> xfs_io> help statx
> statx [-O | -m mask][-FDLA] -- extended information about the currently open file
> 
>  Display extended file status.
> 
>  Options:
>  -m mask -- Specify the field mask for the statx call (default STATX_ALL)
>  -A -- Suppress terminal automount traversal
>  -D -- Don't sync attributes with the server
>  -F -- Force the attributes to be sync'd with the server
>  -L -- Follow symlinks (statx link target)
>  -O -- Add only basic stats (STATX_BASIC_STATS) to default mask
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> 
> V2: Fix dumb typos, add usage for bad options, change the -O meaning,
> remove pretty print code, move all compat #defines to statx.h
> 
> diff --git a/io/init.c b/io/init.c
> index 06002e6..c15a1e1 100644
> --- a/io/init.c
> +++ b/io/init.c
> @@ -86,6 +86,7 @@ init_commands(void)
>  	seek_init();
>  	sendfile_init();
>  	shutdown_init();
> +	stat_init();
>  	sync_init();
>  	sync_range_init();
>  	truncate_init();
> diff --git a/io/io.h b/io/io.h
> index 7e95bd5..952bdb8 100644
> --- a/io/io.h
> +++ b/io/io.h
> @@ -112,6 +112,7 @@ extern void		pwrite_init(void);
>  extern void		quit_init(void);
>  extern void		seek_init(void);
>  extern void		shutdown_init(void);
> +extern void		stat_init(void);
>  extern void		sync_init(void);
>  extern void		truncate_init(void);
>  extern void		utimes_init(void);
> diff --git a/io/stat.c b/io/stat.c
> index 3ae9903..a7aebcd 100644
> --- a/io/stat.c
> +++ b/io/stat.c
> @@ -2,6 +2,9 @@
>   * Copyright (c) 2003-2005 Silicon Graphics, Inc.
>   * All Rights Reserved.
>   *
> + * Copyright (C) 2015, 2017 Red Hat, Inc.
> + * Portions of statx support 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 License as
>   * published by the Free Software Foundation.
> @@ -20,10 +23,14 @@
>  #include "input.h"
>  #include "init.h"
>  #include "io.h"
> +#include "statx.h"
>  #include "libxfs.h"
>  
> +#include <fcntl.h>
> +
>  static cmdinfo_t stat_cmd;
>  static cmdinfo_t statfs_cmd;
> +static cmdinfo_t statx_cmd;
>  
>  off64_t
>  filesize(void)
> @@ -167,6 +174,125 @@ statfs_f(
>  	return 0;
>  }
>  
> +static 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
> +statx_help(void)
> +{
> +        printf(_(
> +"\n"
> +" Display extended file status.\n"
> +"\n"
> +" Options:\n"
> +" -m mask -- Specify the field mask for the statx call (default STATX_ALL)\n"
> +" -A -- Suppress terminal automount traversal\n"
> +" -D -- Don't sync attributes with the server\n"
> +" -F -- Force the attributes to be sync'd with the server\n"
> +" -L -- Follow symlinks (statx link target)\n"
> +" -O -- Add only basic stats (STATX_BASIC_STATS) to default mask\n"
> +"\n"));
> +}
> +
> +/* statx helper */
> +static void
> +dump_statx(struct statx *stx)
> +{
> +	printf("stx_mask: 0x%x\n", stx->stx_mask);
> +	printf("stx_blksize: %u\n", stx->stx_blksize);
> +	printf("stx_attributes: 0x%llx\n", stx->stx_attributes);
> +	printf("stx_nlink: %u\n", stx->stx_nlink);
> +	printf("stx_uid: %u\n", stx->stx_uid);
> +	printf("stx_gid: %u\n", stx->stx_gid);
> +	printf("stx_mode: 0%o\n", stx->stx_mode);
> +	printf("stx_ino: %llu\n", stx->stx_ino);
> +	printf("stx_size: %llu\n", stx->stx_size);
> +	printf("stx_blocks: %llu\n", stx->stx_blocks);
> +	printf("stx_atime.tv_sec: %lld\n", stx->stx_atime.tv_sec);
> +	printf("stx_atime.tv_nsec: %d\n", stx->stx_atime.tv_nsec);
> +	printf("stx_btime.tv_sec: %lld\n", stx->stx_btime.tv_sec);
> +	printf("stx_btime.tv_nsec: %d\n", stx->stx_btime.tv_nsec);
> +	printf("stx_ctime.tv_sec: %lld\n", stx->stx_ctime.tv_sec);
> +	printf("stx_ctime.tv_nsec: %d\n", stx->stx_ctime.tv_nsec);
> +	printf("stx_mtime.tv_sec: %lld\n", stx->stx_mtime.tv_sec);
> +	printf("stx_mtime.tv_nsec: %d\n", stx->stx_mtime.tv_nsec);
> +	printf("stx_rdev_major: %u\n", stx->stx_rdev_major);
> +	printf("stx_rdev_minor: %u\n", stx->stx_rdev_minor);
> +	printf("stx_dev_major: %u\n", stx->stx_dev_major);
> +	printf("stx_dev_minor: %u\n", stx->stx_dev_minor);
> +}
> +
> +/*
> + * options:
> + * 	- input flags - query type
> + * 	- output style for flags (and all else?) (chars vs. hex?)
> + * 	- output - mask out incidental flag or not?
> + */
> +int
> +statx_f(
> +	int		argc,
> +	char		**argv)
> +{
> +	int		c;
> +	struct statx	stx;
> +	int		atflag = AT_SYMLINK_NOFOLLOW;
> +	unsigned int	m_mask = 0;	/* mask requested with -m */
> +	int		Oflag = 0, mflag = 0;	/* -O or -m was used */
> +	unsigned int	mask = STATX_ALL;
> +
> +	while ((c = getopt(argc, argv, "m:FDLOA")) != EOF) {
> +		switch (c) {
> +		case 'm':
> +			m_mask = atoi(optarg);
> +			mflag = 1;
> +			break;
> +		case 'F':
> +			atflag &= ~AT_STATX_SYNC_TYPE;
> +			atflag |= AT_STATX_FORCE_SYNC;
> +			break;
> +		case 'D':
> +			atflag &= ~AT_STATX_SYNC_TYPE;
> +			atflag |= AT_STATX_DONT_SYNC;
> +			break;
> +		case 'L':
> +			atflag &= ~AT_SYMLINK_NOFOLLOW;
> +			break;
> +		case 'O':
> +			mask = STATX_BASIC_STATS;
> +			Oflag = 1;
> +			break;
> +		case 'A':
> +			atflag |= AT_NO_AUTOMOUNT;
> +			break;
> +		default:
> +			return command_usage(&statx_cmd);
> +		}
> +	}
> +
> +	if (Oflag && mflag) {
> +		printf("Cannot specify both -m mask and -O\n");
> +		return 0;
> +	}
> +
> +	/* -m overrides any other mask options */
> +	if (mflag)
> +		mask = m_mask;
> +
> +	memset(&stx, 0xbf, sizeof(stx));
> +	if (statx(AT_FDCWD, file->name, atflag, mask, &stx) < 0) {
> +		perror("statx");
> +		return 0;
> +	}
> +
> +	dump_statx(&stx);
> +
> +	return 0;
> +}
> +
>  void
>  stat_init(void)
>  {
> @@ -176,14 +302,25 @@ stat_init(void)
>  	stat_cmd.argmax = 1;
>  	stat_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
>  	stat_cmd.args = _("[-v]");
> -	stat_cmd.oneline = _("statistics on the currently open file");
> +	stat_cmd.oneline = _("information about the currently open file");
>  
>  	statfs_cmd.name = "statfs";
>  	statfs_cmd.cfunc = statfs_f;
>  	statfs_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
>  	statfs_cmd.oneline =
> -		_("statistics on the filesystem of the currently open file");
> + _("information about the filesystem of the currently open file");
> +
> +	statx_cmd.name = "statx";
> +	statx_cmd.cfunc = statx_f;
> +	statx_cmd.argmin = 0;
> +	statx_cmd.argmax = -1;
> +	statx_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
> +	statx_cmd.args = _("[-O | -m mask][-FDLAP]");
> +	statx_cmd.oneline =
> + _("extended information about the currently open file");
> +	statx_cmd.help = statx_help;
>  
>  	add_command(&stat_cmd);
>  	add_command(&statfs_cmd);
> +	add_command(&statx_cmd);
>  }
> diff --git a/io/statx.h b/io/statx.h
> new file mode 100644
> index 0000000..729a147
> --- /dev/null
> +++ b/io/statx.h
> @@ -0,0 +1,158 @@
> +#ifndef XFS_IO_STATX_H
> +#define XFS_IO_STATX_H
> +
> +#include <unistd.h>
> +
> +#ifndef AT_STATX_SYNC_TYPE
> +#define AT_STATX_SYNC_TYPE      0x6000  /* Type of synchronisation required from statx() */
> +#define AT_STATX_SYNC_AS_STAT   0x0000  /* - Do whatever stat() does */
> +#define AT_STATX_FORCE_SYNC     0x2000  /* - Force the attributes to be sync'd with the server */
> +#define AT_STATX_DONT_SYNC      0x4000  /* - Don't sync attributes with the server */
> +#endif
> +
> +#ifndef AT_NO_AUTOMOUNT
> +#define AT_NO_AUTOMOUNT		0x800	/* Suppress terminal automount traversal */
> +#endif
> +
> +#ifdef __i386__
> +#define __NR_statx 383
> +#elif defined (__ILP32__)
> +#define __NR_statx (__X32_SYSCALL_BIT + 332)
> +#else
> +#define __NR_statx 332
> +#endif
> +
> +#ifndef STATX_TYPE
> +
> +/*
> + * Timestamp structure for the timestamps in struct statx.
> + *
> + * tv_sec holds the number of seconds before (negative) or after (positive)
> + * 00:00:00 1st January 1970 UTC.
> + *
> + * tv_nsec holds a number of nanoseconds before (0..-999,999,999 if tv_sec is
> + * negative) or after (0..999,999,999 if tv_sec is positive) the tv_sec time.
> + *
> + * Note that if both tv_sec and tv_nsec are non-zero, then the two values must
> + * either be both positive or both negative.
> + *
> + * __reserved is held in case we need a yet finer resolution.
> + */
> +struct statx_timestamp {
> +	__s64	tv_sec;
> +	__s32	tv_nsec;
> +	__s32	__reserved;
> +};
> +
> +/*
> + * Structures for the extended file attribute retrieval system call
> + * (statx()).
> + *
> + * The caller passes a mask of what they're specifically interested in as a
> + * parameter to statx().  What statx() actually got will be indicated in
> + * st_mask upon return.
> + *
> + * For each bit in the mask argument:
> + *
> + * - if the datum is not supported:
> + *
> + *   - the bit will be cleared, and
> + *
> + *   - the datum will be set to an appropriate fabricated value if one is
> + *     available (eg. CIFS can take a default uid and gid), otherwise
> + *
> + *   - the field will be cleared;
> + *
> + * - otherwise, if explicitly requested:
> + *
> + *   - the datum will be synchronised to the server if AT_STATX_FORCE_SYNC is
> + *     set or if the datum is considered out of date, and
> + *
> + *   - the field will be filled in and the bit will be set;
> + *
> + * - otherwise, if not requested, but available in approximate form without any
> + *   effort, it will be filled in anyway, and the bit will be set upon return
> + *   (it might not be up to date, however, and no attempt will be made to
> + *   synchronise the internal state first);
> + *
> + * - otherwise the field and the bit will be cleared before returning.
> + *
> + * Items in STATX_BASIC_STATS may be marked unavailable on return, but they
> + * will have values installed for compatibility purposes so that stat() and
> + * co. can be emulated in userspace.
> + */
> +struct statx {
> +	/* 0x00 */
> +	__u32	stx_mask;	/* What results were written [uncond] */
> +	__u32	stx_blksize;	/* Preferred general I/O size [uncond] */
> +	__u64	stx_attributes;	/* Flags conveying information about the file [uncond] */
> +	/* 0x10 */
> +	__u32	stx_nlink;	/* Number of hard links */
> +	__u32	stx_uid;	/* User ID of owner */
> +	__u32	stx_gid;	/* Group ID of owner */
> +	__u16	stx_mode;	/* File mode */
> +	__u16	__spare0[1];
> +	/* 0x20 */
> +	__u64	stx_ino;	/* Inode number */
> +	__u64	stx_size;	/* File size */
> +	__u64	stx_blocks;	/* Number of 512-byte blocks allocated */
> +	__u64	__spare1[1];
> +	/* 0x40 */
> +	struct statx_timestamp	stx_atime;	/* Last access time */
> +	struct statx_timestamp	stx_btime;	/* File creation time */
> +	struct statx_timestamp	stx_ctime;	/* Last attribute change time */
> +	struct statx_timestamp	stx_mtime;	/* Last data modification time */
> +	/* 0x80 */
> +	__u32	stx_rdev_major;	/* Device ID of special file [if bdev/cdev] */
> +	__u32	stx_rdev_minor;
> +	__u32	stx_dev_major;	/* ID of device containing file [uncond] */
> +	__u32	stx_dev_minor;
> +	/* 0x90 */
> +	__u64	__spare2[14];	/* Spare space for future expansion */
> +	/* 0x100 */
> +};
> +
> +/*
> + * Flags to be stx_mask
> + *
> + * Query request/result mask for statx() and struct statx::stx_mask.
> + *
> + * These bits should be set in the mask argument of statx() to request
> + * particular items when calling statx().
> + */
> +#define STATX_TYPE		0x00000001U	/* Want/got stx_mode & S_IFMT */
> +#define STATX_MODE		0x00000002U	/* Want/got stx_mode & ~S_IFMT */
> +#define STATX_NLINK		0x00000004U	/* Want/got stx_nlink */
> +#define STATX_UID		0x00000008U	/* Want/got stx_uid */
> +#define STATX_GID		0x00000010U	/* Want/got stx_gid */
> +#define STATX_ATIME		0x00000020U	/* Want/got stx_atime */
> +#define STATX_MTIME		0x00000040U	/* Want/got stx_mtime */
> +#define STATX_CTIME		0x00000080U	/* Want/got stx_ctime */
> +#define STATX_INO		0x00000100U	/* Want/got stx_ino */
> +#define STATX_SIZE		0x00000200U	/* Want/got stx_size */
> +#define STATX_BLOCKS		0x00000400U	/* Want/got stx_blocks */
> +#define STATX_BASIC_STATS	0x000007ffU	/* The stuff in the normal stat struct */
> +#define STATX_BTIME		0x00000800U	/* Want/got stx_btime */
> +#define STATX_ALL		0x00000fffU	/* All currently supported flags */
> +
> +/*
> + * Attributes to be found in stx_attributes
> + *
> + * These give information about the features or the state of a file that might
> + * be of use to ordinary userspace programs such as GUIs or ls rather than
> + * specialised tools.
> + *
> + * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS
> + * semantically.  Where possible, the numerical value is picked to correspond
> + * also.
> + */
> +#define STATX_ATTR_COMPRESSED		0x00000004 /* [I] File is compressed by the fs */
> +#define STATX_ATTR_IMMUTABLE		0x00000010 /* [I] File is marked immutable */
> +#define STATX_ATTR_APPEND		0x00000020 /* [I] File is append-only */
> +#define STATX_ATTR_NODUMP		0x00000040 /* [I] File is not to be dumped */
> +#define STATX_ATTR_ENCRYPTED		0x00000800 /* [I] File requires key to decrypt in fs */
> +
> +#define STATX_ATTR_AUTOMOUNT		0x00001000 /* Dir: Automount trigger */
> +
> +#endif /* STATX_TYPE */
> +#endif /* XFS_IO_STATX_H */
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 19e1ae4..022f0ea 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -880,6 +880,32 @@ and the XFS_IOC_GETXATTR system call on the current file. If the
>  option is specified, the atime (last access), mtime
>  (last modify), and ctime (last change) timestamps are also displayed.
>  .TP
> +.BR statx " [ " \-O " | " "\-m mask" " ][ \-" FDLA " ]"
> +Extended information from the statx syscall.
> +.RS 1.0i
> +.PD 0
> +.TP 0.4i
> +.B \-m mask
> +Specify the field mask for the statx call (default STATX_ALL)
> +.TP
> +.B \-O
> +Add only basic stats (STATX_BASIC_STATS) to default mask
> +.TP
> +.B \-F
> +Force the attributes to be sync'd with the server
> +.TP
> +.B \-D
> +Don't sync attributes with the server
> +.TP
> +.B \-L
> +Follow symlinks (statx link target)
> +.TP
> +.B \-A
> +Suppress terminal automount traversal
> +.TP
> +.RE
> +.IP
> +.TP
>  .B statfs
>  Selected statistics from
>  .BR statfs (2)
> 
> 
> 
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