xfs_io: add support for stx_mnt_id and stx_version fieldsiversion

Add support for the new mnt_id field and the proposed change_attr field
in statx to xfs_io. Add a new autoconf test to see whether the system's
struct statx has the requisite fields. If not, or if there is no struct
statx defined, then use the internal definitions in statx.h.

Wrap most of the preprocessor constants in #ifdefs so that we only
redefine the values needed. Since we can't undefine a struct definition,
postfix their names with "_internal" and use the preprocessor to
override the struct definitions.

Cc: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

5 files changed, 50 insertions, 9 deletions

diff --git a/configure.ac b/configure.ac
index 212da02e95..e9ff57c7dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -187,6 +187,7 @@ AC_HAVE_FSETXATTR
 AC_HAVE_MREMAP
 AC_NEED_INTERNAL_FSXATTR
 AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG
+AC_NEED_INTERNAL_STATX
 AC_HAVE_GETFSMAP
 AC_HAVE_STATFS_FLAGS
 AC_HAVE_MAP_SYNC
diff --git a/include/builddefs.in b/include/builddefs.in
index e0a2f3cbc9..4c690ee3a8 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -110,6 +110,7 @@ HAVE_FSETXATTR = @have_fsetxattr@
 HAVE_MREMAP = @have_mremap@
 NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@
 NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@
+NEED_INTERNAL_STATX = @need_internal_statx@
 HAVE_GETFSMAP = @have_getfsmap@
 HAVE_STATFS_FLAGS = @have_statfs_flags@
 HAVE_MAP_SYNC = @have_map_sync@
@@ -155,6 +156,9 @@ endif
 ifeq ($(NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG),yes)
 PCFLAGS+= -DOVERRIDE_SYSTEM_FSCRYPT_ADD_KEY_ARG
 endif
+ifeq ($(NEED_INTERNAL_STATX),yes)
+PCFLAGS+= -DOVERRIDE_SYSTEM_STATX
+endif
 ifeq ($(HAVE_GETFSMAP),yes)
 PCFLAGS+= -DHAVE_GETFSMAP
 endif
diff --git a/io/stat.c b/io/stat.c
index b57f9eefed..0dcc04fedf 100644
--- a/io/stat.c
+++ b/io/stat.c
@@ -17,6 +17,8 @@
 
 #include <fcntl.h>
 
+#define IO_STATX_MASK	(STATX_ALL | STATX_MNT_ID | STATX_VERSION)
+
 static cmdinfo_t stat_cmd;
 static cmdinfo_t statfs_cmd;
 static cmdinfo_t statx_cmd;
@@ -349,6 +351,8 @@ dump_raw_statx(struct statx *stx)
 	printf("stat.rdev_minor = %u\n", stx->stx_rdev_minor);
 	printf("stat.dev_major = %u\n", stx->stx_dev_major);
 	printf("stat.dev_minor = %u\n", stx->stx_dev_minor);
+	printf("stat.mnt_id = 0x%llx\n", stx->stx_mnt_id);
+	printf("stat.version = 0x%llx\n", stx->stx_version);
 	return 0;
 }
 
@@ -367,7 +371,7 @@ statx_f(
 	char		*p;
 	struct statx	stx;
 	int		atflag = 0;
-	unsigned int	mask = STATX_ALL;
+	unsigned int	mask = IO_STATX_MASK;
 
 	while ((c = getopt(argc, argv, "m:rvFD")) != EOF) {
 		switch (c) {
@@ -375,7 +379,7 @@ statx_f(
 			if (strcmp(optarg, "basic") == 0)
 				mask = STATX_BASIC_STATS;
 			else if (strcmp(optarg, "all") == 0)
-				mask = STATX_ALL;
+				mask = IO_STATX_MASK;
 			else {
 				mask = strtoul(optarg, &p, 0);
 				if (!p || p == optarg) {
diff --git a/io/statx.h b/io/statx.h
index c6625ac431..2cc26ecf8a 100644
--- a/io/statx.h
+++ b/io/statx.h
@@ -5,6 +5,7 @@
 
 #include <unistd.h>
 #include <sys/syscall.h>
+#include <sys/types.h>
 
 #ifndef AT_EMPTY_PATH
 #define AT_EMPTY_PATH	0x1000
@@ -37,10 +38,10 @@
 #ifndef STATX_TYPE
 /* Pick up kernel definitions if glibc didn't already provide them */
 #include <linux/stat.h>
-#endif
+#endif /* STATX_TYPE */
 
-#ifndef STATX_TYPE
-/* Local definitions if glibc & kernel headers didn't already provide them */
+#ifdef OVERRIDE_SYSTEM_STATX
+/* Local definitions if they don't exist or are too old */
 
 /*
  * Timestamp structure for the timestamps in struct statx.
@@ -56,11 +57,12 @@
  *
  * __reserved is held in case we need a yet finer resolution.
  */
-struct statx_timestamp {
+struct statx_timestamp_internal {
 	__s64	tv_sec;
 	__s32	tv_nsec;
 	__s32	__reserved;
 };
+#define statx_timestamp statx_timestamp_internal
 
 /*
  * Structures for the extended file attribute retrieval system call
@@ -99,7 +101,7 @@ struct statx_timestamp {
  * will have values installed for compatibility purposes so that stat() and
  * co. can be emulated in userspace.
  */
-struct statx {
+struct statx_internal {
 	/* 0x00 */
 	__u32	stx_mask;	/* What results were written [uncond] */
 	__u32	stx_blksize;	/* Preferred general I/O size [uncond] */
@@ -126,9 +128,15 @@ struct statx {
 	__u32	stx_dev_major;	/* ID of device containing file [uncond] */
 	__u32	stx_dev_minor;
 	/* 0x90 */
-	__u64	__spare2[14];	/* Spare space for future expansion */
+	__u64	stx_mnt_id;
+	__u32   stx_dio_mem_align;      /* Memory buffer alignment for direct I/O */
+	__u32   stx_dio_offset_align;   /* File offset alignment for direct I/O */
+	/* 0xa0 */
+	__u64	stx_version;	/* Inode change counter */
+	__u64	__spare2[11];	/* Spare space for future expansion */
 	/* 0x100 */
 };
+#define statx statx_internal
 
 /*
  * Flags to be stx_mask
@@ -138,6 +146,7 @@ struct statx {
  * These bits should be set in the mask argument of statx() to request
  * particular items when calling statx().
  */
+#ifndef STATX_TYPE
 #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 */
@@ -153,6 +162,13 @@ struct statx {
 #define STATX_BTIME		0x00000800U	/* Want/got stx_btime */
 #define STATX_ALL		0x00000fffU	/* All currently supported flags */
 #define STATX__RESERVED		0x80000000U	/* Reserved for future struct statx expansion */
+#endif /* STATX_TYPE */
+
+#ifndef STATX_VERSION
+#define STATX_MNT_ID		0x00001000U	/* Got stx_mnt_id */
+#define STATX_DIOALIGN		0x00002000U	/* Want/got direct I/O alignment info */
+#define STATX_VERSION		0x00004000U	/* Want/got stx_version */
+#endif /* STATX_VERSION */
 
 /*
  * Attributes to be found in stx_attributes
@@ -165,6 +181,7 @@ struct statx {
  * semantically.  Where possible, the numerical value is picked to correspond
  * also.
  */
+#ifndef STATX_ATTR_COMPRESSED
 #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 */
@@ -172,6 +189,7 @@ struct statx {
 #define STATX_ATTR_ENCRYPTED		0x00000800 /* [I] File requires key to decrypt in fs */
 
 #define STATX_ATTR_AUTOMOUNT		0x00001000 /* Dir: Automount trigger */
+#endif /* STATX_ATTR_COMPRESSED */
 
-#endif /* STATX_TYPE */
+#endif /* OVERRIDE_SYSTEM_STATX */
 #endif /* XFS_IO_STATX_H */
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index bb1ab49c11..8fde375183 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -507,3 +507,17 @@ AC_DEFUN([AC_PACKAGE_CHECK_LTO],
     AC_SUBST(lto_cflags)
     AC_SUBST(lto_ldflags)
   ])
+
+AC_DEFUN([AC_NEED_INTERNAL_STATX],
+  [ AC_CHECK_TYPE(struct statx,
+      [
+        AC_CHECK_MEMBER(struct statx.stx_change_attr,
+          ,
+          need_internal_statx=yes,
+          [#include <linux/stat.h>]
+        )
+      ],,
+      [#include <linux/stat.h>]
+    )
+    AC_SUBST(need_internal_statx)
+  ])