mke2fs: get device topology values from blkid

Handle automatic selection of stride/stripe:

mke2fs 1.41.9 (22-Aug-2009)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=16 blocks, Stripe width=32 blocks
...

And warn on block device misalignment:

mke2fs 1.41.9 (22-Aug-2009)
/dev/sdc1 alignment is offset by 32256 bytes.
This may result in very poor performance, (re)-partitioning suggested.
Proceed anyway? (y,n)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

configure

@@ -15737,6 +15737,95 @@ _ACEOF
 
 fi
 
+if test -n "$BLKID_CMT"; then
+  { $as_echo "$as_me:$LINENO: checking for library containing blkid_probe_all" >&5
+$as_echo_n "checking for library containing blkid_probe_all... " >&6; }
+if test "${ac_cv_search_blkid_probe_all+set}" = set; then
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char blkid_probe_all ();
+int
+main ()
+{
+return blkid_probe_all ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' blkid; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
+$as_echo "$ac_try_echo") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext && {
+	 test "$cross_compiling" = yes ||
+	 $as_test_x conftest$ac_exeext
+       }; then
+  ac_cv_search_blkid_probe_all=$ac_res
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+
+fi
+
+rm -rf conftest.dSYM
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext
+  if test "${ac_cv_search_blkid_probe_all+set}" = set; then
+  break
+fi
+done
+if test "${ac_cv_search_blkid_probe_all+set}" = set; then
+  :
+else
+  ac_cv_search_blkid_probe_all=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:$LINENO: result: $ac_cv_search_blkid_probe_all" >&5
+$as_echo "$ac_cv_search_blkid_probe_all" >&6; }
+ac_res=$ac_cv_search_blkid_probe_all
+if test "$ac_res" != no; then
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+fi
 
 
 
@@ -15770,7 +15859,8 @@ fi
 
 
 
-for ac_func in chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit
+
+for ac_func in chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit blkid_probe_get_topology2
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5

configure.in

@@ -802,7 +802,14 @@ AC_CHECK_MEMBER(struct sockaddr.sa_len,
 	[#include <sys/types.h>
 	 #include <sys/socket.h>])
 dnl
-AC_CHECK_FUNCS(chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit)
+dnl This will add -lblkid to the AC_CHECK_FUNCS search if we are using
+dnl the system-provided blkid library
+dnl
+if test -n "$BLKID_CMT"; then
+  AC_SEARCH_LIBS([blkid_probe_all], [blkid])
+fi
+dnl
+AC_CHECK_FUNCS(chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit blkid_probe_get_topology2)
 dnl
 dnl Check to see if -lsocket is required (solaris) to make something
 dnl that uses socket() to compile; this is needed for the UUID library

misc/mke2fs.c

@@ -49,6 +49,7 @@ extern int optind;
 #include <sys/types.h>
 #include <libgen.h>
 #include <limits.h>
+#include <blkid/blkid.h>
 
 #include "ext2fs/ext2_fs.h"
 #include "et/com_err.h"
@@ -614,6 +615,8 @@ static void show_stats(ext2_filsys fs)
 		s->s_log_block_size);
 	printf(_("Fragment size=%u (log=%u)\n"), fs->fragsize,
 		s->s_log_frag_size);
+	printf(_("Stride=%u blocks, Stripe width=%u blocks\n"),
+	       s->s_raid_stride, s->s_raid_stripe_width);
 	printf(_("%u inodes, %u blocks\n"), s->s_inodes_count,
 	       s->s_blocks_count);
 	printf(_("%u blocks (%2.2f%%) reserved for the super user\n"),
@@ -1073,6 +1076,43 @@ static int get_bool_from_profile(char **fs_types, const char *opt, int def_val)
 extern const char *mke2fs_default_profile;
 static const char *default_files[] = { "<default>", 0 };
 
+#ifdef HAVE_BLKID_PROBE_GET_TOPOLOGY
+/*
+ * Sets the geometry of a device (stripe/stride), and returns the
+ * device's alignment offset, if any, or a negative error.
+ */
+static int ext2fs_get_device_geometry(const char *file,
+				      struct ext2_super_block *fs_param)
+{
+	int rc = -1;
+	int blocksize;
+	blkid_probe pr;
+	blkid_topology tp;
+	unsigned long min_io;
+	unsigned long opt_io;
+
+	pr = blkid_new_probe_from_filename(file);
+	if (!pr)
+		goto out;
+
+	tp = blkid_probe_get_topology(pr);
+	if (!tp)
+		goto out;
+
+	min_io = blkid_topology_get_minimum_io_size(tp);
+	opt_io = blkid_topology_get_optimal_io_size(tp);
+	blocksize = EXT2_BLOCK_SIZE(fs_param);
+
+	fs_param->s_raid_stride = min_io / blocksize;
+	fs_param->s_raid_stripe_width = opt_io / blocksize;
+
+	rc = blkid_topology_get_alignment_offset(tp);
+out:
+	blkid_free_probe(pr);
+	return rc;
+}
+#endif
+
 static void PRS(int argc, char *argv[])
 {
 	int		b, c;
@@ -1633,6 +1673,21 @@ got_size:
 	fs_param.s_log_frag_size = fs_param.s_log_block_size =
 		int_log2(blocksize >> EXT2_MIN_BLOCK_LOG_SIZE);
 
+#ifdef HAVE_BLKID_PROBE_GET_TOPOLOGY
+	retval = ext2fs_get_device_geometry(device_name, &fs_param);
+	if (retval < 0) {
+		fprintf(stderr,
+			_("warning: Unable to get device geometry for %s"),
+			device_name);
+	} else if (retval) {
+		printf(_("%s alignment is offset by %lu bytes.\n"),
+		       device_name, retval);
+		printf(_("This may result in very poor performance, "
+			  "(re)-partitioning suggested.\n"));
+		proceed_question();
+	}
+#endif
+
 	blocksize = EXT2_BLOCK_SIZE(&fs_param);
 
 	lazy_itable_init = get_bool_from_profile(fs_types,