Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.

It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?

From David Howells.

Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:

    https://www.spinics.net/lists/linux-fsdevel/msg33831.html

* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  statx: Add a system call to make enhanced file info available

4 files changed, 271 insertions, 1 deletions

diff --git a/samples/Kconfig b/samples/Kconfig
index b124f62ed6cb..9cb63188d3ef 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -112,4 +112,10 @@ config SAMPLE_VFIO_MDEV_MTTY
 	  Build a virtual tty sample driver for use as a VFIO
 	  mediated device
 
+config SAMPLE_STATX
+	bool "Build example extended-stat using code"
+	depends on BROKEN
+	help
+	  Build example userspace program to use the new extended-stat syscall.
+
 endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index 86a137e451d9..db54e766ddb1 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -3,4 +3,4 @@
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ trace_events/ livepatch/ \
 			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
 			   configfs/ connector/ v4l/ trace_printk/ blackfin/ \
-			   vfio-mdev/
+			   vfio-mdev/ statx/
diff --git a/samples/statx/Makefile b/samples/statx/Makefile
new file mode 100644
index 000000000000..1f80a3d8cf45
--- /dev/null
+++ b/samples/statx/Makefile
@@ -0,0 +1,10 @@
+# kbuild trick to avoid linker error. Can be omitted if a module is built.
+obj- := dummy.o
+
+# List of programs to build
+hostprogs-$(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..8571d766331d
--- /dev/null
+++ b/samples/statx/test-statx.c
@@ -0,0 +1,254 @@
+/* Test the statx() system call.
+ *
+ * Note that the output of this program is intended to look like the output of
+ * /bin/stat where possible.
+ *
+ * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <sys/stat.h>
+
+#define AT_STATX_SYNC_TYPE	0x6000
+#define AT_STATX_SYNC_AS_STAT	0x0000
+#define AT_STATX_FORCE_SYNC	0x2000
+#define AT_STATX_DONT_SYNC	0x4000
+
+static __attribute__((unused))
+ssize_t statx(int dfd, const char *filename, unsigned flags,
+	      unsigned int mask, struct statx *buffer)
+{
+	return syscall(__NR_statx, dfd, filename, flags, mask, buffer);
+}
+
+static void print_time(const char *field, struct statx_timestamp *ts)
+{
+	struct tm tm;
+	time_t tim;
+	char buffer[100];
+	int len;
+
+	tim = ts->tv_sec;
+	if (!localtime_r(&tim, &tm)) {
+		perror("localtime_r");
+		exit(1);
+	}
+	len = strftime(buffer, 100, "%F %T", &tm);
+	if (len == 0) {
+		perror("strftime");
+		exit(1);
+	}
+	printf("%s", field);
+	fwrite(buffer, 1, len, stdout);
+	printf(".%09u", ts->tv_nsec);
+	len = strftime(buffer, 100, "%z", &tm);
+	if (len == 0) {
+		perror("strftime2");
+		exit(1);
+	}
+	fwrite(buffer, 1, len, stdout);
+	printf("\n");
+}
+
+static void dump_statx(struct statx *stx)
+{
+	char buffer[256], ft = '?';
+
+	printf("results=%x\n", stx->stx_mask);
+
+	printf(" ");
+	if (stx->stx_mask & STATX_SIZE)
+		printf(" Size: %-15llu", (unsigned long long)stx->stx_size);
+	if (stx->stx_mask & STATX_BLOCKS)
+		printf(" Blocks: %-10llu", (unsigned long long)stx->stx_blocks);
+	printf(" IO Block: %-6llu", (unsigned long long)stx->stx_blksize);
+	if (stx->stx_mask & STATX_TYPE) {
+		switch (stx->stx_mode & S_IFMT) {
+		case S_IFIFO:	printf("  FIFO\n");			ft = 'p'; break;
+		case S_IFCHR:	printf("  character special file\n");	ft = 'c'; break;
+		case S_IFDIR:	printf("  directory\n");		ft = 'd'; break;
+		case S_IFBLK:	printf("  block special file\n");	ft = 'b'; break;
+		case S_IFREG:	printf("  regular file\n");		ft = '-'; break;
+		case S_IFLNK:	printf("  symbolic link\n");		ft = 'l'; break;
+		case S_IFSOCK:	printf("  socket\n");			ft = 's'; break;
+		default:
+			printf(" unknown type (%o)\n", stx->stx_mode & S_IFMT);
+			break;
+		}
+	} else {
+		printf(" no type\n");
+	}
+
+	sprintf(buffer, "%02x:%02x", stx->stx_dev_major, stx->stx_dev_minor);
+	printf("Device: %-15s", buffer);
+	if (stx->stx_mask & STATX_INO)
+		printf(" Inode: %-11llu", (unsigned long long) stx->stx_ino);
+	if (stx->stx_mask & STATX_NLINK)
+		printf(" Links: %-5u", stx->stx_nlink);
+	if (stx->stx_mask & STATX_TYPE) {
+		switch (stx->stx_mode & S_IFMT) {
+		case S_IFBLK:
+		case S_IFCHR:
+			printf(" Device type: %u,%u",
+			       stx->stx_rdev_major, stx->stx_rdev_minor);
+			break;
+		}
+	}
+	printf("\n");
+
+	if (stx->stx_mask & STATX_MODE)
+		printf("Access: (%04o/%c%c%c%c%c%c%c%c%c%c)  ",
+		       stx->stx_mode & 07777,
+		       ft,
+		       stx->stx_mode & S_IRUSR ? 'r' : '-',
+		       stx->stx_mode & S_IWUSR ? 'w' : '-',
+		       stx->stx_mode & S_IXUSR ? 'x' : '-',
+		       stx->stx_mode & S_IRGRP ? 'r' : '-',
+		       stx->stx_mode & S_IWGRP ? 'w' : '-',
+		       stx->stx_mode & S_IXGRP ? 'x' : '-',
+		       stx->stx_mode & S_IROTH ? 'r' : '-',
+		       stx->stx_mode & S_IWOTH ? 'w' : '-',
+		       stx->stx_mode & S_IXOTH ? 'x' : '-');
+	if (stx->stx_mask & STATX_UID)
+		printf("Uid: %5d   ", stx->stx_uid);
+	if (stx->stx_mask & STATX_GID)
+		printf("Gid: %5d\n", stx->stx_gid);
+
+	if (stx->stx_mask & STATX_ATIME)
+		print_time("Access: ", &stx->stx_atime);
+	if (stx->stx_mask & STATX_MTIME)
+		print_time("Modify: ", &stx->stx_mtime);
+	if (stx->stx_mask & STATX_CTIME)
+		print_time("Change: ", &stx->stx_ctime);
+	if (stx->stx_mask & STATX_BTIME)
+		print_time(" Birth: ", &stx->stx_btime);
+
+	if (stx->stx_attributes) {
+		unsigned char bits;
+		int loop, byte;
+
+		static char attr_representation[64 + 1] =
+			/* STATX_ATTR_ flags: */
+			"????????"	/* 63-56 */
+			"????????"	/* 55-48 */
+			"????????"	/* 47-40 */
+			"????????"	/* 39-32 */
+			"????????"	/* 31-24	0x00000000-ff000000 */
+			"????????"	/* 23-16	0x00000000-00ff0000 */
+			"???me???"	/* 15- 8	0x00000000-0000ff00 */
+			"?dai?c??"	/*  7- 0	0x00000000-000000ff */
+			;
+
+		printf("Attributes: %016llx (", stx->stx_attributes);
+		for (byte = 64 - 8; byte >= 0; byte -= 8) {
+			bits = stx->stx_attributes >> byte;
+			for (loop = 7; loop >= 0; loop--) {
+				int bit = byte + loop;
+
+				if (bits & 0x80)
+					putchar(attr_representation[63 - bit]);
+				else
+					putchar('-');
+				bits <<= 1;
+			}
+			if (byte)
+				putchar(' ');
+		}
+		printf(")\n");
+	}
+}
+
+static void dump_hex(unsigned long long *data, int from, int to)
+{
+	unsigned offset, print_offset = 1, col = 0;
+
+	from /= 8;
+	to = (to + 7) / 8;
+
+	for (offset = from; offset < to; offset++) {
+		if (print_offset) {
+			printf("%04x: ", offset * 8);
+			print_offset = 0;
+		}
+		printf("%016llx", data[offset]);
+		col++;
+		if ((col & 3) == 0) {
+			printf("\n");
+			print_offset = 1;
+		} else {
+			printf(" ");
+		}
+	}
+
+	if (!print_offset)
+		printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct statx stx;
+	int ret, raw = 0, atflag = AT_SYMLINK_NOFOLLOW;
+
+	unsigned int mask = STATX_ALL;
+
+	for (argv++; *argv; argv++) {
+		if (strcmp(*argv, "-F") == 0) {
+			atflag &= ~AT_STATX_SYNC_TYPE;
+			atflag |= AT_STATX_FORCE_SYNC;
+			continue;
+		}
+		if (strcmp(*argv, "-D") == 0) {
+			atflag &= ~AT_STATX_SYNC_TYPE;
+			atflag |= AT_STATX_DONT_SYNC;
+			continue;
+		}
+		if (strcmp(*argv, "-L") == 0) {
+			atflag &= ~AT_SYMLINK_NOFOLLOW;
+			continue;
+		}
+		if (strcmp(*argv, "-O") == 0) {
+			mask &= ~STATX_BASIC_STATS;
+			continue;
+		}
+		if (strcmp(*argv, "-A") == 0) {
+			atflag |= AT_NO_AUTOMOUNT;
+			continue;
+		}
+		if (strcmp(*argv, "-R") == 0) {
+			raw = 1;
+			continue;
+		}
+
+		memset(&stx, 0xbf, sizeof(stx));
+		ret = statx(AT_FDCWD, *argv, atflag, mask, &stx);
+		printf("statx(%s) = %d\n", *argv, ret);
+		if (ret < 0) {
+			perror(*argv);
+			exit(1);
+		}
+
+		if (raw)
+			dump_hex((unsigned long long *)&stx, 0, sizeof(stx));
+
+		dump_statx(&stx);
+	}
+	return 0;
+}