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Date: Mon, 28 Feb 2011 11:09:43 +0800
From: Yongqiang Yang <xiaoqiangnk@...il.com>
To: Robin Dong <hao.bigrat@...il.com>
Cc: linux-ext4@...r.kernel.org, tytso@....edu,
Robin Dong <sanbai@...bao.com>
Subject: Re: [PATCH 1/2] mksparse: build sparse file from compressed e2image file.
Hi Robin,
Are there many zero-blocks in /dev/sda1 usually? If so, is there a
ratio of zero-blocks?
On Mon, Feb 28, 2011 at 10:35 AM, Robin Dong <hao.bigrat@...il.com> wrote:
> From: Robin Dong <sanbai@...bao.com>
>
> [Purpose]
> After we make a image-file by e2image like:
> #e2image -r /dev/hda1 - | bzip2 > hda1.bz2
> we copy the bz2 file to remote host and extract it:
> #bunzip2 hda1.bz2
> the unzipped hda1 file will not be a sparse file and the space occupied
> by it is as large as the real /dev/hda1 filesystem.
>
> Therefore a tool to transform a raw-file to a sparse-file is necessary.
> This Patch is a first attempt to provide such a tool which is called
> 'mksparse' so far.
>
> [Example]
> Extract hda1.bz2 by:
> #bunzip2 -c hda1.bz2 | mksparse hda1
> the hda1 file will be a sparse file.
>
> Reviewed-by: Coly Li <bosong.ly@...bao.com>
> Signed-off-by: Robin Dong <sanbai@...bao.com>
> ---
> misc/Makefile.in | 21 ++++-
> misc/mksparse.c | 268 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 285 insertions(+), 4 deletions(-)
> create mode 100644 misc/mksparse.c
>
> diff --git a/misc/Makefile.in b/misc/Makefile.in
> index 86ee53f..fcd316e 100644
> --- a/misc/Makefile.in
> +++ b/misc/Makefile.in
> @@ -17,6 +17,8 @@ INSTALL = @INSTALL@
> @IMAGER_CMT@...MAGE_PROG= e2image
> @IMAGER_CMT@...MAGE_MAN= e2image.8
>
> +@...GER_CMT@...PARSE_PROG= mksparse
> +
> @UUIDD_CMT@...DD_PROG= uuidd
> @UUIDD_CMT@...DD_MAN= uuidd.8
>
> @@ -27,7 +29,7 @@ INSTALL = @INSTALL@
> @BLKID_CMT@...DFS_MAN= findfs.8
>
> SPROGS= mke2fs badblocks tune2fs dumpe2fs $(BLKID_PROG) logsave \
> - $(E2IMAGE_PROG) @FSCK_PROG@ e2undo
> + $(E2IMAGE_PROG) $(MKSPARSE_PROG) @FSCK_PROG@ e2undo
> USPROGS= mklost+found filefrag e2freefrag $(UUIDD_PROG) $(E4DEFRAG_PROG)
> SMANPAGES= tune2fs.8 mklost+found.8 mke2fs.8 dumpe2fs.8 badblocks.8 \
> e2label.8 $(FINDFS_MAN) $(BLKID_MAN) $(E2IMAGE_MAN) \
> @@ -50,6 +52,7 @@ UUIDD_OBJS= uuidd.o
> DUMPE2FS_OBJS= dumpe2fs.o
> BADBLOCKS_OBJS= badblocks.o
> E2IMAGE_OBJS= e2image.o
> +MKSPARSE_OBJS= mksparse.o
> FSCK_OBJS= fsck.o base_device.o ismounted.o
> BLKID_OBJS= blkid.o
> FILEFRAG_OBJS= filefrag.o
> @@ -68,6 +71,7 @@ PROFILED_UUIDD_OBJS= profiled/uuidd.o
> PROFILED_DUMPE2FS_OBJS= profiled/dumpe2fs.o
> PROFILED_BADBLOCKS_OBJS= profiled/badblocks.o
> PROFILED_E2IMAGE_OBJS= profiled/e2image.o
> +PROFILED_MKSPARSE_OBJS= profiled/mksparse.o
> PROFILED_FSCK_OBJS= profiled/fsck.o profiled/base_device.o \
> profiled/ismounted.o
> PROFILED_BLKID_OBJS= profiled/blkid.o
> @@ -109,7 +113,7 @@ all:: profiled $(SPROGS) $(UPROGS) $(USPROGS) $(SMANPAGES) $(UMANPAGES) \
> @PROFILE_CMT@all:: tune2fs.profiled blkid.profiled e2image.profiled \
> e2undo.profiled mke2fs.profiled dumpe2fs.profiled fsck.profiled \
> logsave.profiled filefrag.profiled uuidgen.profiled uuidd.profiled \
> - e2image.profiled e4defrag.profiled
> + e2image.profiled mksparse.profiled e4defrag.profiled
>
> profiled:
> @PROFILE_CMT@ $(E) " MKDIR $@"
> @@ -187,6 +191,15 @@ e2image.profiled: $(PROFILED_E2IMAGE_OBJS) $(PROFILED_DEPLIBS)
> $(Q) $(CC) $(ALL_LDFLAGS) -g -pg -o e2image.profiled \
> $(PROFILED_E2IMAGE_OBJS) $(PROFILED_LIBS) $(LIBINTL)
>
> +mksparse: $(MKSPARSE_OBJS) $(DEPLIBS)
> + $(E) " LD $@"
> + $(Q) $(CC) $(ALL_LDFLAGS) -o mksparse $(MKSPARSE_OBJS) $(LIBS) $(LIBINTL)
> +
> +mksparse.profiled: $(PROFILED_MKSPARSE_OBJS) $(PROFILED_DEPLIBS)
> + $(E) " LD $@"
> + $(Q) $(CC) $(ALL_LDFLAGS) -g -pg -o mksparse.profiled \
> + $(PROFILED_MKSPARSE_OBJS) $(PROFILED_LIBS) $(LIBINTL)
> +
> e2undo: $(E2UNDO_OBJS) $(DEPLIBS)
> $(E) " LD $@"
> $(Q) $(CC) $(ALL_LDFLAGS) -o e2undo $(E2UNDO_OBJS) $(LIBS) $(LIBINTL)
> @@ -550,8 +563,8 @@ clean:
> $(FMANPAGES) \
> base_device base_device.out mke2fs.static filefrag e2freefrag \
> e2initrd_helper partinfo prof_err.[ch] default_profile.c \
> - uuidd e2image tune2fs.static tst_ismounted fsck.profiled \
> - blkid.profiled tune2fs.profiled e2image.profiled \
> + uuidd e2image mksparse tune2fs.static tst_ismounted fsck.profiled \
> + blkid.profiled tune2fs.profiled e2image.profiled mksparse.profiled\
> e2undo.profiled mke2fs.profiled dumpe2fs.profiled \
> logsave.profiled filefrag.profiled uuidgen.profiled \
> uuidd.profiled e2image.profiled \
> diff --git a/misc/mksparse.c b/misc/mksparse.c
> new file mode 100644
> index 0000000..9e62fcf
> --- /dev/null
> +++ b/misc/mksparse.c
> @@ -0,0 +1,268 @@
> +/*
> + * mksparse.c --- Program which transform stdin (or file) to
> + * be a new sparse file.
> + *
> + * Copyright 2011 by Taobao, all rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public
> + * License, version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * Authors: Robin Dong <sanbai@...bao.com>
> + */
> +
> +#define _LARGEFILE_SOURCE
> +#define _LARGEFILE64_SOURCE
> +
> +#include <fcntl.h>
> +#include <grp.h>
> +#ifdef HAVE_GETOPT_H
> +#include <getopt.h>
> +#else
> +extern char *optarg;
> +extern int optind;
> +#endif
> +#include <stdio.h>
> +#ifdef HAVE_STDLIB_H
> +#include <stdlib.h>
> +#endif
> +#include <string.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <errno.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <limits.h>
> +
> +#include "ext2fs/ext2fs.h"
> +
> +#include "../version.h"
> +#include "nls-enable.h"
> +
> +#define KB_SIZE 1024
> +#define MB_SIZE (1024*1024)
> +#define MIN_BUFFER_SIZE 1024
> +#define MAX_BUFFER_SIZE (64*1024*1024)
> +#define DEFAULT_BUFFER_SIZE (4*1024)
> +
> +#define OPEN_SRC_FAIL -1
> +#define OPEN_TARGET_FAIL -2
> +#define MALLOC_FAIL -3
> +#define SEEK_FAIL -4
> +#define WRITE_FAIL -5
> +
> +const char *program_name = "mksparse";
> +
> +static void usage(void)
> +{
> + fprintf(stderr,
> + _("Usage: %s [-s buffer_size] [-i input_file] sparse_file\n"),
> + program_name);
> + exit (1);
> +}
> +
> +static int get_buffer_size(const char *optarg)
> +{
> + char *pos = NULL;
> + long val = strtol(optarg, &pos, 0);
> + if (pos == optarg || val == LONG_MAX)
> + return DEFAULT_BUFFER_SIZE;
> +
> + switch (*pos) {
> + case 'k':
> + case 'K':
> + val *= KB_SIZE;
> + break;
> + case 'm':
> + case 'M':
> + val *= MB_SIZE;
> + break;
> + case 'b':
> + case 'B':
> + case '\0':
> + break;
> + default:
> + fprintf(stderr, _("Wrong buffer_size %s\n"), optarg);
> + val = -1;
> + goto out;
> + /*
> + * never touch here
> + */
> + break;
> + }
> +
> + /*
> + * the buffer_size must in thec range [1KB, 64MB]
> + */
> + if (val > MAX_BUFFER_SIZE) {
> + fprintf(stderr,
> + _("Buffer_size is too large, "
> + "change it to %d bytes\n"),
> + MAX_BUFFER_SIZE);
> + val = MAX_BUFFER_SIZE;
> + }
> +
> + if (val < MIN_BUFFER_SIZE) {
> + fprintf(stderr,
> + _("Buffer_size is too small, "
> + "change it to %d bytes\n"),
> + MIN_BUFFER_SIZE);
> + val = MIN_BUFFER_SIZE;
> + }
> +
> + /*
> + * up-align to MIN_BUFFER_SIZE
> + */
> + val &= ~(MIN_BUFFER_SIZE - 1);
> +
> +out:
> + return val;
> +}
> +
> +static int check_zero(const char *buffer, int buffer_size)
> +{
> + long *wp = (long *)buffer;
> +
> + while (*(wp++) == 0) {
> + if ((const char *)wp >= buffer + buffer_size)
> + break;
> + }
> +
> + return (const char *)wp >= buffer + buffer_size;
> +}
> +
> +int main (int argc, char **argv)
> +{
> + int c;
> + char *buffer = NULL;
> + char *if_name = NULL;
> + char *of_name = NULL;
> + int buffer_size = DEFAULT_BUFFER_SIZE;
> + int source_fd = 0;
> + int target_fd = 0;
> + ssize_t ret = 0;
> + int need = 0;
> + int loop;
> + int err_num = 0;
> +
> +#ifdef ENABLE_NLS
> + setlocale(LC_MESSAGES, "");
> + setlocale(LC_CTYPE, "");
> + bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
> + textdomain(NLS_CAT_NAME);
> +#endif
> + fprintf (stderr, "mksparse %s (%s)\n", E2FSPROGS_VERSION,
> + E2FSPROGS_DATE);
> + if (argc && *argv)
> + program_name = *argv;
> + while ((c = getopt (argc, argv, "s:i:")) != EOF)
> + switch (c) {
> + case 's':
> + buffer_size = get_buffer_size(optarg);
> + if (buffer_size < 0)
> + return -1;
> + break;
> + case 'i':
> + if_name = optarg;
> + break;
> + default:
> + usage();
> + }
> +
> + if (optind != argc - 1)
> + usage();
> +
> + add_error_table(&et_ext2_error_table);
> +
> + of_name = argv[optind];
> +
> + if (!if_name) {
> + source_fd = 0;
> + } else {
> + source_fd = open(if_name, O_RDONLY);
> + if (source_fd < 0) {
> + com_err (program_name, errno,
> + _("while trying to open %s"), if_name);
> + err_num = OPEN_SRC_FAIL;
> + goto out;
> + }
> + }
> +
> + target_fd = open(of_name, O_CREAT|O_TRUNC|O_WRONLY, 0600);
> + if (target_fd < 0) {
> + com_err (program_name, errno,
> + _("while trying to open %s"), of_name);
> + err_num = OPEN_TARGET_FAIL;
> + goto out;
> + }
> +
> + buffer = malloc(buffer_size);
> + if (!buffer) {
> + com_err (program_name, ENOMEM, _("while allocating buffer"));
> + err_num = MALLOC_FAIL;
> + goto out;
> + }
> +
> + loop = 1;
> + do {
> + need = buffer_size;
> + while (need > 0) {
> + ret = read (source_fd,
> + buffer + (buffer_size - need),
> + need);
> + if (ret < 0) {
> + if (loop == 0)
> + break;
> + else {
> + loop = 0;
> + continue;
> + }
> + } else if (ret == 0) {
> + loop = 0;
> + break;
> + } else {
> + if (loop == 0)
> + loop = 1;
> + need -= ret;
> + }
> + }
> +
> + if (need == 0 && check_zero(buffer, buffer_size)) {
> + ret = lseek(target_fd, buffer_size, SEEK_CUR);
> + if (ret == (off_t)(-1)) {
> + com_err (program_name, errno,
> + _("while lseeking %d"), ret);
> + err_num = SEEK_FAIL;
> + goto out;
> + }
> + } else if (need < buffer_size) {
> + ret = write(target_fd, buffer, buffer_size - need);
> + if (ret < 0) {
> + com_err (program_name,
> + errno, _("while writeing"));
> + err_num = WRITE_FAIL;
> + goto out;
> + }
> + }
> + } while (loop);
> +
> +out:
> + if (buffer)
> + free(buffer);
> +
> + if (target_fd > 0) {
> + fsync(target_fd);
> + close(target_fd);
> + }
> +
> + if (source_fd > 0)
> + close(source_fd);
> +
> + remove_error_table(&et_ext2_error_table);
> + return (!err_num) ? 0 : -1;
> +}
> --
> 1.7.3.5
>
> --
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--
Best Wishes
Yongqiang Yang
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