[PATCH] Add e4migrate

[PATCH] Add e4migrate

[Aneesh Kumar K.V]

This patch adds new command e4migrate. This can be used
to convert ext3 file system to ext4 file system.
Once we have the e4defrag we may want to merge the
migrate with defrag. This will enables us to do a defrag
immediately after migrate resulting in better disk layout.
This will also enables us to defrag ext3 inodes

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

---
 misc/Makefile.in    |   17 ++++++++++++--
 misc/e4migrate.8.in |   28 +++++++++++++++++++++++++
 misc/e4migrate.c    |   57 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/misc/Makefile.in b/misc/Makefile.in
index a81df8a..7ebeaf7 100644
--- a/misc/Makefile.in
+++ b/misc/Makefile.in
@@ -18,11 +18,12 @@ INSTALL = @INSTALL@
 @UUIDD_CMT@UUIDD_MAN= uuidd.8
 
 SPROGS=		mke2fs badblocks tune2fs dumpe2fs blkid logsave \
-			$(E2IMAGE_PROG) @FSCK_PROG@ e2undo
+			$(E2IMAGE_PROG) @FSCK_PROG@ e2undo e4migrate
 USPROGS=	mklost+found filefrag $(UUIDD_PROG)
 SMANPAGES=	tune2fs.8 mklost+found.8 mke2fs.8 dumpe2fs.8 badblocks.8 \
 			e2label.8 findfs.8 blkid.8 $(E2IMAGE_MAN) \
-			logsave.8 filefrag.8 e2undo.8 $(UUIDD_MAN) @FSCK_MAN@
+			logsave.8 filefrag.8 e2undo.8 e4migrate.8 \
+			$(UUIDD_MAN) @FSCK_MAN@
 FMANPAGES=	mke2fs.conf.5
 
 UPROGS=		chattr lsattr uuidgen
@@ -44,6 +45,7 @@ FSCK_OBJS=	fsck.o base_device.o ismounted.o
 BLKID_OBJS=	blkid.o
 FILEFRAG_OBJS=	filefrag.o
 E2UNDO_OBJS=  e2undo.o
+E4MIGRATE_OBJS = e4migrate.o
 
 XTRA_CFLAGS=	-I$(srcdir)/../e2fsck -I.
 
@@ -53,7 +55,7 @@ SRCS=	$(srcdir)/tune2fs.c $(srcdir)/mklost+found.c $(srcdir)/mke2fs.c \
 		$(srcdir)/uuidgen.c $(srcdir)/blkid.c $(srcdir)/logsave.c \
 		$(srcdir)/filefrag.c $(srcdir)/base_device.c \
 		$(srcdir)/ismounted.c $(srcdir)/../e2fsck/profile.c \
-		$(srcdir)/e2undo.c
+		$(srcdir)/e2undo.c $(srcdir)/e4migrate.c
 
 LIBS= $(LIBEXT2FS) $(LIBCOM_ERR) 
 DEPLIBS= $(LIBEXT2FS) $(LIBCOM_ERR) 
@@ -124,6 +126,10 @@ e2undo: $(E2UNDO_OBJS) $(DEPLIBS)
 	@echo "	LD $@"
 	@$(CC) $(ALL_LDFLAGS) -o e2undo $(E2UNDO_OBJS) $(LIBS) $(LIBINTL)
 
+e4migrate: $(E4MIGRATE_OBJS)
+	@echo "	LD $@"
+	@$(CC) $(ALL_LDFLAGS) -o e4migrate $(E4MIGRATE_OBJS) $(LIBINTL)
+
 base_device: base_device.c
 	@echo "	LD $@"
 	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) $(srcdir)/base_device.c \
@@ -213,6 +219,10 @@ e2undo.8: $(DEP_SUBSTITUTE) $(srcdir)/e2undo.8.in
 	@echo "	SUBST $@"
 	@$(SUBSTITUTE_UPTIME) $(srcdir)/e2undo.8.in e2undo.8
 
+e4migrate.8: $(DEP_SUBSTITUTE) $(srcdir)/e4migrate.8.in
+	@echo "	SUBST $@"
+	@$(SUBSTITUTE_UPTIME) $(srcdir)/e4migrate.8.in e4migrate.8
+
 findfs.8: $(DEP_SUBSTITUTE) $(srcdir)/findfs.8.in
 	@echo "	SUBST $@"
 	@$(SUBSTITUTE_UPTIME) $(srcdir)/findfs.8.in findfs.8
@@ -505,3 +515,4 @@ ismounted.o: $(srcdir)/ismounted.c $(top_srcdir)/lib/et/com_err.h
 profile.o: $(srcdir)/../e2fsck/profile.c $(top_srcdir)/lib/et/com_err.h \
  $(srcdir)/../e2fsck/profile.h prof_err.h
 e2undo.o: $(srcdir)/e2undo.c $(top_srcdir)/lib/ext2fs/tdb.h
+e4migrate.o: $(srcdir)/e4migrate.c
diff --git a/misc/e4migrate.8.in b/misc/e4migrate.8.in
new file mode 100644
index 0000000..e9a0466
--- /dev/null
+++ b/misc/e4migrate.8.in
@@ -0,0 +1,28 @@
+.\" -*- nroff -*-
+.\" Copyright 2008 by Aneesh Kumar K.V.  All Rights Reserved.
+.\" This file may be copied under the terms of the GNU Public License.
+.\"
+.TH E4MIGRATE 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
+.SH NAME
+e4migrate \- Migrate an ext3 inode to ext4 inode format
+.SH SYNOPSIS
+.B e4migrate
+.I filename
+.SH DESCRIPTION
+.B e4migrate
+will migrate
+.I  filename
+in ext3 inode format to ext4 inode format
+This can be
+used to migrate an ext3 file system to ext4 file system
+.SH AUTHOR
+.B e4migrate
+was written by Aneesh Kumar K.V. (aneesh.kumar@linux.vnet.ibm.com)
+.SH AVAILABILITY
+.B e2undo
+is part of the e2fsprogs package and is available from
+http://e2fsprogs.sourceforge.net.
+.SH SEE ALSO
+.BR mke2fs (8),
+.BR tune2fs (8)
+
diff --git a/misc/e4migrate.c b/misc/e4migrate.c
new file mode 100644
index 0000000..4948849
--- /dev/null
+++ b/misc/e4migrate.c
@@ -0,0 +1,57 @@
+#include <stdio.h>
+#include <fcntl.h>
+#if HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#if HAVE_GETOPT_H
+#include <getopt.h>
+#endif
+#if HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#if HAVE_STRING_H
+#include <string.h>
+#endif
+#if HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#include "nls-enable.h"
+
+
+
+#define EXT4_IOC_MIGRATE                _IO('f', 7)
+static void usage(char *prg_name)
+{
+	fprintf(stderr,
+		_("Usage: %s <filename>\n"), prg_name);
+	exit(1);
+}
+static void migrate(char *filename)
+{
+	int fd, retval;
+	fd = open(filename, O_RDWR);
+	if (fd < 0) {
+		fprintf(stderr, _("Failed to open the file %s\n"), filename);
+		exit(1);
+	}
+	retval = ioctl(fd, EXT4_IOC_MIGRATE, NULL);
+	if (retval) {
+		fprintf(stderr,
+			_("Migrate failed for file %s with error: %s\n"),
+			filename, strerror(errno));
+		exit(1);
+	} else
+		printf(_("Successfully migrated %s\n"), filename);
+}
+
+int main(int argc, char *argv[])
+{
+	if (argc != 2) {
+		usage(argv[0]);
+	}
+
+	migrate(argv[1]);
+	return 0;
+}
+
+
-- 
tg: (b55d739..) an/e4migrate (depends on: master)

Re: [PATCH] Add e4migrate

[Andreas Dilger]

On Sep 05, 2008  15:41 +0530, Aneesh Kumar wrote:
> +e4migrate \- Migrate an ext3 inode to ext4 inode format
> +.B e4migrate will migrate filename in ext3 inode format to ext4 inode format
> +This can be used to migrate an ext3 file system to ext4 file system

Can you please explain a bit more about what is done here?  Is it changing
block mapped inodes to extent mapped?  Resising the inodes/GDT? Changing
other things like growing large inode space for ns timestamps/version?

We have an option to e2fsck (like -D for rehash directory, but instead
"-E expand_extra_isize") to resize the "extra_isize" of an existing inode
to ensure that enough space is in the filesystem for i_version_hi, if it
isn't already.  This is in our patch "e2fsprogs-expand-extra-isize.patch"
in the Lustre patchset.

I think it makes more sense to have options for existing tools, rather
than having 10 new different tools, but maybe Ted has other opinions.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.