Patchwork [v2] e2image: add -a switch to include all data

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Submitter Phillip Susi
Date July 6, 2012, 8:08 p.m.
Message ID <1341605332-26568-1-git-send-email-psusi@ubuntu.com>
Download mbox | patch
Permalink /patch/169538/
State Superseded
Headers show

Comments

Phillip Susi - July 6, 2012, 8:08 p.m.
Normally the raw and QCOW2 images only contain fs metadata.
Add a new switch ( -a ) to include all data.  This makes it
possible to use e2image to clone a whole filesystem.

Signed-off-by: Phillip Susi <psusi@ubuntu.com>
---
 misc/e2image.8.in |   22 +++++++++++++++++++++-
 misc/e2image.c    |   31 ++++++++++++++++++++++++-------
 2 files changed, 45 insertions(+), 8 deletions(-)

Patch

diff --git a/misc/e2image.8.in b/misc/e2image.8.in
index 8876e77..f8205a6 100644
--- a/misc/e2image.8.in
+++ b/misc/e2image.8.in
@@ -8,7 +8,7 @@  e2image \- Save critical ext2/ext3/ext4 filesystem metadata to a file
 .SH SYNOPSIS
 .B e2image
 [
-.B \-rsI
+.B \-rsIQa
 ]
 .I device
 .I image-file
@@ -171,6 +171,26 @@  is regular QCOW2 image and can be processed by tools aware of QCOW2 format
 such as for example
 .BR qemu-img .
 .PP
+You can convert a qcow2 image into a raw image with:
+.PP
+.br
+\	\fBe2image \-r hda1.qcow2 hda1.raw\fR
+.br
+.PP
+This can be useful to write a qcow2 image containing all data to a
+sparse image file where it can be loop mounted, or to a disk partition.
+Note that this may not work with qcow2 images not generated by e2image.
+.PP
+.SH INCLUDING DATA
+Normally
+.B e2image
+only includes fs metadata, not regular file data.  The 
+.B \-a
+option can be specified to include all data.  This will
+give an image that is suitible to use to clone the entire FS or
+for backup purposes.  Note that this option only works with the
+raw or QCOW2 formats.
+.PP
 .SH AUTHOR
 .B e2image
 was written by Theodore Ts'o (tytso@mit.edu).
diff --git a/misc/e2image.c b/misc/e2image.c
index 3a956ef..3e4b717 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -52,6 +52,9 @@  extern int optind;
 
 const char * program_name = "e2image";
 char * device_name = NULL;
+char all_data;
+char output_is_blk;
+/* writing to blk device: don't skip zeroed blocks */
 
 static void lseek_error_and_exit(int errnum)
 {
@@ -84,7 +87,7 @@  static int get_bits_from_size(size_t size)
 
 static void usage(void)
 {
-	fprintf(stderr, _("Usage: %s [-rsIQ] device image_file\n"),
+	fprintf(stderr, _("Usage: %s [-rsIQa] device image_file\n"),
 		program_name);
 	exit (1);
 }
@@ -309,7 +312,7 @@  static int process_file_block(ext2_filsys fs EXT2FS_ATTR((unused)),
 			      int ref_offset EXT2FS_ATTR((unused)),
 			      void *priv_data EXT2FS_ATTR((unused)))
 {
-	if (blockcnt < 0) {
+	if (blockcnt < 0 || all_data) {
 		ext2fs_mark_block_bitmap2(meta_block_map, *block_nr);
 		meta_blocks_count++;
 	}
@@ -341,11 +344,12 @@  static void mark_table_blocks(ext2_filsys fs)
 		/*
 		 * Mark the blocks used for the inode table
 		 */
-		if (!ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
+		if ((output_is_blk || !ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)) &&
 		    ext2fs_inode_table_loc(fs, i)) {
 			unsigned int end = (unsigned) fs->inode_blocks_per_group;
 			/* skip unused blocks */
-			if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+			if (!output_is_blk &&
+			    EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 						       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
 				end -= (ext2fs_bg_itable_unused(fs, i) /
 					EXT2_INODES_PER_BLOCK(fs->super));
@@ -387,6 +391,8 @@  static int check_zero_block(char *buf, int blocksize)
 	char	*cp = buf;
 	int	left = blocksize;
 
+	if (output_is_blk)
+		return 0;
 	while (left > 0) {
 		if (*cp++)
 			return 0;
@@ -1134,7 +1140,7 @@  static void write_raw_image_file(ext2_filsys fs, int fd, int type, int flags)
 			if ((inode.i_flags & EXT4_EXTENTS_FL) ||
 			    inode.i_block[EXT2_IND_BLOCK] ||
 			    inode.i_block[EXT2_DIND_BLOCK] ||
-			    inode.i_block[EXT2_TIND_BLOCK]) {
+			    inode.i_block[EXT2_TIND_BLOCK] || all_data) {
 				retval = ext2fs_block_iterate3(fs,
 				       ino, BLOCK_FLAG_READ_ONLY, block_buf,
 				       process_file_block, &pb);
@@ -1249,6 +1255,7 @@  int main (int argc, char ** argv)
 	int qcow2_fd = 0;
 	int fd = 0;
 	int ret = 0;
+	struct stat st;
 
 #ifdef ENABLE_NLS
 	setlocale(LC_MESSAGES, "");
@@ -1262,7 +1269,7 @@  int main (int argc, char ** argv)
 	if (argc && *argv)
 		program_name = *argv;
 	add_error_table(&et_ext2_error_table);
-	while ((c = getopt(argc, argv, "rsIQ")) != EOF)
+	while ((c = getopt(argc, argv, "rsIQa")) != EOF)
 		switch (c) {
 		case 'I':
 			flags |= E2IMAGE_INSTALL_FLAG;
@@ -1280,6 +1287,9 @@  int main (int argc, char ** argv)
 		case 's':
 			flags |= E2IMAGE_SCRAMBLE_FLAG;
 			break;
+		case 'a':
+			all_data = 1;
+			break;
 		default:
 			usage();
 		}
@@ -1327,7 +1337,14 @@  skip_device:
 					 "the stdout!\n");
 		exit(1);
 	}
-
+	if (fd != 1) {
+		if (fstat(fd, &st)) {
+			com_err(program_name, 0, "Can not stat output\n");
+			exit(1);
+		}
+		if (S_ISBLK(st.st_mode))
+			output_is_blk = 1;
+	}
 	if (flags & E2IMAGE_IS_QCOW2_FLAG) {
 		ret = qcow2_write_raw_image(qcow2_fd, fd, header);
 		if (ret) {