win32: make stat(2) fetch additional metadata

Modify the WIN32 implementation of stat(2) to fetch inode number,
device id and number of hardlinks.  This requires opening a handle
to the target file so it will be slower.

A number of features can be enabled or start to work:

- tar can detect if an archive is being stored in itself;
- find can support the -inum and -links options;
- ls can display inode numbers;
- diff can detect attempts to compare a file with itself;
- du has better support for hardlinked files;
- cp can detect attempts to copy a file over itself.

12 files changed, 74 insertions, 16 deletions

diff --git a/Config.in b/Config.in
index 0318a6aff..9f8d4bf7c 100644
--- a/Config.in
+++ b/Config.in
@@ -463,6 +463,16 @@ config FEATURE_EURO
         requires the OEM code page to be 858.  If the OEM code page of
         the console is 850 when BusyBox starts it's changed to 858.
 
+config FEATURE_EXTRA_FILE_DATA
+        bool "Read additional file metadata (1.3 kb)"
+        default y
+        depends on PLATFORM_MINGW32
+        help
+        Read additional file metadata: device id, inode number and number
+        of hard links.  This may slow down some file operations but it
+        permits extra features such as warning of attempts to copy a file
+        onto itself or to store a tar archive in itself.
+
 comment 'Build Options'
 
 config STATIC
diff --git a/archival/tar.c b/archival/tar.c
index b9ae93004..54989b953 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -161,7 +161,7 @@ typedef struct TarBallInfo {
 # endif
         HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
         HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
-#if !ENABLE_PLATFORM_MINGW32
+#if !ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA
 //TODO: save only st_dev + st_ino
         struct stat tarFileStatBuf;     /* Stat info for the tarball, letting
                                          * us know the inode and device that the
@@ -529,7 +529,7 @@ static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statb
                 }
         }
 
-#if !ENABLE_PLATFORM_MINGW32
+#if !ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA
         /* It is a bad idea to store the archive we are in the process of creating,
          * so check the device and inode to be sure that this particular file isn't
          * the new tarball */
@@ -707,7 +707,7 @@ static NOINLINE int writeTarFile(
 
         /*tbInfo->hlInfoHead = NULL; - already is */
 
-#if !ENABLE_PLATFORM_MINGW32
+#if !ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA
         /* Store the stat info for the tarball's file, so
          * can avoid including the tarball into itself....  */
         xfstat(tbInfo->tarFd, &tbInfo->tarFileStatBuf, "can't stat tar file");
diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index aec3b97e7..cb74f8c20 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -48,6 +48,8 @@ CONFIG_FEATURE_ICON=y
 # CONFIG_FEATURE_ICON_ATERM is not set
 # CONFIG_FEATURE_ICON_STERM is not set
 CONFIG_FEATURE_ICON_ALL=y
+CONFIG_FEATURE_EURO=y
+CONFIG_FEATURE_EXTRA_FILE_DATA=y
 
 #
 # Build Options
@@ -457,7 +459,7 @@ CONFIG_FEATURE_FIND_EXECUTABLE=y
 # CONFIG_FEATURE_FIND_XDEV is not set
 CONFIG_FEATURE_FIND_MAXDEPTH=y
 CONFIG_FEATURE_FIND_NEWER=y
-# CONFIG_FEATURE_FIND_INUM is not set
+CONFIG_FEATURE_FIND_INUM=y
 CONFIG_FEATURE_FIND_EXEC=y
 CONFIG_FEATURE_FIND_EXEC_PLUS=y
 # CONFIG_FEATURE_FIND_USER is not set
@@ -472,7 +474,7 @@ CONFIG_FEATURE_FIND_DELETE=y
 CONFIG_FEATURE_FIND_PATH=y
 CONFIG_FEATURE_FIND_REGEX=y
 # CONFIG_FEATURE_FIND_CONTEXT is not set
-# CONFIG_FEATURE_FIND_LINKS is not set
+CONFIG_FEATURE_FIND_LINKS=y
 CONFIG_GREP=y
 CONFIG_EGREP=y
 CONFIG_FGREP=y
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index 4fa2a1735..a0569b23a 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -48,6 +48,8 @@ CONFIG_FEATURE_ICON=y
 # CONFIG_FEATURE_ICON_ATERM is not set
 # CONFIG_FEATURE_ICON_STERM is not set
 CONFIG_FEATURE_ICON_ALL=y
+CONFIG_FEATURE_EURO=y
+CONFIG_FEATURE_EXTRA_FILE_DATA=y
 
 #
 # Build Options
@@ -457,7 +459,7 @@ CONFIG_FEATURE_FIND_EXECUTABLE=y
 # CONFIG_FEATURE_FIND_XDEV is not set
 CONFIG_FEATURE_FIND_MAXDEPTH=y
 CONFIG_FEATURE_FIND_NEWER=y
-# CONFIG_FEATURE_FIND_INUM is not set
+CONFIG_FEATURE_FIND_INUM=y
 CONFIG_FEATURE_FIND_EXEC=y
 CONFIG_FEATURE_FIND_EXEC_PLUS=y
 # CONFIG_FEATURE_FIND_USER is not set
@@ -472,7 +474,7 @@ CONFIG_FEATURE_FIND_DELETE=y
 CONFIG_FEATURE_FIND_PATH=y
 CONFIG_FEATURE_FIND_REGEX=y
 # CONFIG_FEATURE_FIND_CONTEXT is not set
-# CONFIG_FEATURE_FIND_LINKS is not set
+CONFIG_FEATURE_FIND_LINKS=y
 CONFIG_GREP=y
 CONFIG_EGREP=y
 CONFIG_FGREP=y
diff --git a/coreutils/ls.c b/coreutils/ls.c
index 48927c964..a1782ed45 100644
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -499,7 +499,11 @@ static NOINLINE unsigned display_single(const struct dnode *dn)
 #endif
 
         if (opt & OPT_i) /* show inode# */
+#if !ENABLE_FEATURE_EXTRA_FILE_DATA
                 column += printf("%7"LL_FMT"u ", (long long) dn->dn_ino);
+#else
+                column += printf("%19"LL_FMT"u ", (long long) dn->dn_ino);
+#endif
 //TODO: -h should affect -s too:
         if (opt & OPT_s) /* show allocated blocks */
                 column += printf("%6"OFF_FMT"u ", (off_t) (dn->dn_blocks >> 1));
diff --git a/editors/diff.c b/editors/diff.c
index 929beb054..815c8a915 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -1039,7 +1039,8 @@ int diff_main(int argc UNUSED_PARAM, char **argv)
          * single NFS file system, if a local device number (st_dev) exceeds
          * 255, or if a local inode number (st_ino) exceeds 16777215.
          */
-        if (ENABLE_DESKTOP && !ENABLE_PLATFORM_MINGW32
+        if (ENABLE_DESKTOP
+         && (!ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA)
          && stb[0].st_ino == stb[1].st_ino
          && stb[0].st_dev == stb[1].st_dev
          && stb[0].st_size == stb[1].st_size
diff --git a/findutils/find.c b/findutils/find.c
index 06ad1b39c..0381f0685 100644
--- a/findutils/find.c
+++ b/findutils/find.c
@@ -121,7 +121,7 @@
 //config:config FEATURE_FIND_INUM
 //config:       bool "Enable -inum: inode number matching"
 //config:       default y
-//config:       depends on FIND
+//config:       depends on FIND && (PLATFORM_POSIX || FEATURE_EXTRA_FILE_DATA)
 //config:
 //config:config FEATURE_FIND_EXEC
 //config:       bool "Enable -exec: execute commands"
@@ -227,7 +227,7 @@
 //config:config FEATURE_FIND_LINKS
 //config:       bool "Enable -links: link count matching"
 //config:       default y
-//config:       depends on FIND
+//config:       depends on FIND && (PLATFORM_POSIX || FEATURE_EXTRA_FILE_DATA)
 //config:       help
 //config:       Support the 'find -links' option for matching number of links.
 
@@ -1361,7 +1361,11 @@ static action*** parse_params(char **argv)
                         action_inum *ap;
                         dbg("%d", __LINE__);
                         ap = ALLOC_ACTION(inum);
+# if !ENABLE_FEATURE_EXTRA_FILE_DATA
                         ap->inode_num = xatoul(arg1);
+# else
+                        ap->inode_num = xatoull(arg1);
+# endif
                 }
 #endif
 #if ENABLE_FEATURE_FIND_USER
diff --git a/include/libbb.h b/include/libbb.h
index 0c7e03ee8..61574b5ee 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1712,7 +1712,7 @@ int bb_xioctl(int fd, unsigned request, void *argp) FAST_FUNC;
 #define xioctl(fd,request,argp)        bb_xioctl(fd,request,argp)
 #endif
 
-#if !ENABLE_PLATFORM_MINGW32
+#if !ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA
 char *is_in_ino_dev_hashtable(const struct stat *statbuf) FAST_FUNC;
 void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name) FAST_FUNC;
 void reset_ino_dev_hashtable(void) FAST_FUNC;
diff --git a/include/mingw.h b/include/mingw.h
index 185eb66ed..0f403b993 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -283,6 +283,9 @@ int mingw_chmod(const char *path, int mode);
 typedef int nlink_t;
 typedef int blksize_t;
 typedef off_t blkcnt_t;
+#if ENABLE_FEATURE_EXTRA_FILE_DATA
+#define ino_t uint64_t
+#endif
 
 struct mingw_stat {
         dev_t     st_dev;
diff --git a/libbb/Kbuild.src b/libbb/Kbuild.src
index b298040ac..799f6d01a 100644
--- a/libbb/Kbuild.src
+++ b/libbb/Kbuild.src
@@ -98,6 +98,7 @@ lib-$(CONFIG_PLATFORM_POSIX) += getpty.o
 lib-$(CONFIG_PLATFORM_POSIX) += get_volsize.o
 lib-$(CONFIG_PLATFORM_POSIX) += inet_common.o
 lib-$(CONFIG_PLATFORM_POSIX) += inode_hash.o
+lib-$(CONFIG_FEATURE_EXTRA_FILE_DATA) += inode_hash.o
 lib-$(CONFIG_PLATFORM_POSIX) += kernel_version.o
 lib-$(CONFIG_PLATFORM_POSIX) += login.o
 lib-$(CONFIG_PLATFORM_POSIX) += makedev.o
diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 299cd7bea..db7a00060 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -105,7 +105,7 @@ int FAST_FUNC copy_file(const char *source, const char *dest, int flags)
                         return -1;
                 }
         } else {
-#if !ENABLE_PLATFORM_MINGW32
+#if !ENABLE_PLATFORM_MINGW32 || ENABLE_FEATURE_EXTRA_FILE_DATA
         /* MinGW does not have inode, and does not use device */
                 if (source_stat.st_dev == dest_stat.st_dev
                  && source_stat.st_ino == dest_stat.st_ino
diff --git a/win32/mingw.c b/win32/mingw.c
index 8217ec772..03636a04b 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -403,7 +403,7 @@ static int do_lstat(int follow, const char *file_name, struct mingw_stat *buf)
                 buf->st_ino = 0;
                 buf->st_uid = DEFAULT_UID;
                 buf->st_gid = DEFAULT_GID;
-                buf->st_nlink = 1;
+                buf->st_nlink = S_ISDIR(buf->st_mode) ? 2 : 1;
                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
                 if (S_ISREG(buf->st_mode) &&
                                 (has_exe_suffix(file_name) || has_exec_format(file_name)))
@@ -434,6 +434,30 @@ static int do_lstat(int follow, const char *file_name, struct mingw_stat *buf)
                         }
                 }
 
+#if ENABLE_FEATURE_EXTRA_FILE_DATA
+                {
+                        BY_HANDLE_FILE_INFORMATION hdata;
+                        HANDLE fh = CreateFile(file_name, 0,
+                                                        0, NULL, OPEN_EXISTING,
+                                                        FILE_ATTRIBUTE_NORMAL|FILE_FLAG_BACKUP_SEMANTICS,
+                                                        NULL);
+                        if (fh != INVALID_HANDLE_VALUE) {
+                                if (GetFileInformationByHandle(fh, &hdata)) {
+                                        buf->st_dev = hdata.dwVolumeSerialNumber;
+                                        buf->st_ino = hdata.nFileIndexLow |
+                                                (((uint64_t)hdata.nFileIndexHigh)<<32);
+                                        buf->st_nlink = S_ISDIR(buf->st_mode) ? 2 :
+                                                                                hdata.nNumberOfLinks;
+                                }
+                                CloseHandle(fh);
+                        }
+                        else {
+                                errno = err_win_to_posix(GetLastError());
+                                return -1;
+                        }
+                }
+#endif
+
                 /*
                  * Assume a block is 4096 bytes and calculate number of 512 byte
                  * sectors.
@@ -522,12 +546,19 @@ int mingw_fstat(int fd, struct mingw_stat *buf)
                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
                 buf->st_blocks = ((buf->st_size+4095)>>12)<<3;
  success:
-                buf->st_dev = buf->st_rdev = 0;
+#if ENABLE_FEATURE_EXTRA_FILE_DATA
+                buf->st_dev = fdata.dwVolumeSerialNumber;
+                buf->st_ino = fdata.nFileIndexLow |
+                        (((uint64_t)fdata.nFileIndexHigh)<<32);
+                buf->st_nlink = S_ISDIR(buf->st_mode) ? 2 : fdata.nNumberOfLinks;
+#else
+                buf->st_dev = 0;
                 buf->st_ino = 0;
+                buf->st_nlink = S_ISDIR(buf->st_mode) ? 2 : 1;
+#endif
+                buf->st_rdev = 0;
                 buf->st_uid = DEFAULT_UID;
                 buf->st_gid = DEFAULT_GID;
-                /* could use fdata.nNumberOfLinks but it's inconsistent with stat */
-                buf->st_nlink = 1;
                 buf->st_blksize = 4096;
                 return 0;
         }