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

2 files changed, 136 insertions, 0 deletions

diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
index beed138bd359..813afd6eee71 100644
--- a/include/uapi/linux/fcntl.h
+++ b/include/uapi/linux/fcntl.h
@@ -63,5 +63,10 @@
 #define AT_NO_AUTOMOUNT         0x800   /* Suppress terminal automount traversal */
 #define AT_EMPTY_PATH           0x1000  /* Allow empty relative pathname */
 
+#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 /* _UAPI_LINUX_FCNTL_H */
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 7fec7e36d921..51a6b86e3700 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 +42,135 @@
 
 #endif
 
+/*
+ * 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 /* _UAPI_LINUX_STAT_H */