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sfdisk: add --move-data 

Signed-off-by: Karel Zak <kzak@redhat.com>
This commit is contained in:
Karel Zak 2015-09-08 16:37:08 +02:00
parent 9a17d9460a
commit f42205d89a
2 changed files with 227 additions and 11 deletions
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29
disk-utils/sfdisk.8
View File

@ -133,7 +133,7 @@ Back up the current partition table sectors before starting the partitioning.
The default backup file name is ~/sfdisk-<device>-<offset>.bak; to use another
name see option \fB\-O\fR, \fB\-\-backup\-file\fR.
.TP
.BR \-\-color [ \fI=when ]
.BR \-\-color[\fI=when]
Colorize the output. The optional argument \fIwhen\fP
can be \fBauto\fR, \fBnever\fR or \fBalways\fR. If the \fIwhen\fR argument is omitted,
it defaults to \fBauto\fR. The colors can be disabled; for the current built-in default
@ -155,6 +155,33 @@ Do not check through the re-read-partition-table ioctl whether the device is in
.BR \-O , " \-\-backup\-file " \fIpath\fR
Override the default backup file name. Note that the device name and offset
are always appended to the file name.
.TP
.BR \-\-move-data[\fI=path]
Move data after partition relocation, for example when move begin of the
partition to another place on the disk. The size of the partition has to be the
same, the new and old location may overlap. The option requires \fB\-N\fR to be
processed on one specified partition only.
The \fIpath\fR overrides the default log file name
(the default is ~/sfdisk-<devname>.move). The log file contains information
about all read/write oprations with the partition data.
Note that this operation is ricky and not atomic. \fBDon't forget to backup your data!\fR
The example below creates 100MiB free area before the first partition and moves
data (e.g. filesystem), the next command creates a new partition from the free
space (at offset 2048) and the last command reorder partitions to match disk
order (original sdc1 will be sdc2).
.RS
.sp
.B "echo '+100M,' | sfdisk --move-data /dev/sdc -N 1"
.br
.B "echo '2048,' | sfdisk /dev/sdc --append
.br
.B sfdisk /dev/sdc --reorder
.sp
.RE
.TP
.BR \-o , " \-\-output " \fIlist
Specify which output columns to print. Use

209
disk-utils/sfdisk.c
View File

@ -30,6 +30,7 @@
#include <getopt.h>
#include <sys/stat.h>
#include <assert.h>
#include <fcntl.h>
#include <libsmartcols.h>
#ifdef HAVE_LIBREADLINE
# include <readline/readline.h>
@ -46,6 +47,7 @@
#include "all-io.h"
#include "rpmatch.h"
#include "loopdev.h"
#include "xalloc.h"
#include "libfdisk.h"
#include "fdisk-list.h"
@ -89,9 +91,11 @@ struct sfdisk {
const char *label; /* --label <label> */
const char *label_nested; /* --label-nested <label> */
const char *backup_file; /* -O <path> */
const char *move_typescript; /* --movedata <typescript> */
char *prompt;
struct fdisk_context *cxt; /* libfdisk context */
struct fdisk_context *cxt; /* libfdisk context */
struct fdisk_partition *orig_pa; /* -N <partno> before the change */
unsigned int verify : 1, /* call fdisk_verify_disklabel() */
quiet : 1, /* suppres extra messages */
@ -102,6 +106,7 @@ struct sfdisk {
container : 1, /* PT contains container (MBR extended) partitions */
append : 1, /* don't create new PT, append partitions only */
json : 1, /* JSON dump */
movedata: 1, /* move data after resize */
noact : 1; /* do not write to device */
};
@ -243,6 +248,21 @@ static int sfdisk_deinit(struct sfdisk *sf)
return 0;
}
static struct fdisk_partition *get_partition(struct fdisk_context *cxt, size_t partno)
{
struct fdisk_table *tb = NULL;
struct fdisk_partition *pa;
if (fdisk_get_partitions(cxt, &tb) != 0)
return NULL;
pa = fdisk_table_get_partition_by_partno(tb, partno);
if (pa)
fdisk_ref_partition(pa);
fdisk_unref_table(tb);
return pa;
}
static void backup_sectors(struct sfdisk *sf,
const char *tpl,
const char *name,
@ -287,6 +307,26 @@ fail:
errx(EXIT_FAILURE, _("%s: failed to create a backup"), devname);
}
static char *mk_backup_filename_tpl(const char *filename, const char *devname, const char *suffix)
{
char *tpl = NULL;
char *name, *buf = xstrdup(devname);
name = basename(buf);
if (!filename) {
const char *home = getenv ("HOME");
if (!home)
errx(EXIT_FAILURE, _("failed to create a backup file, $HOME undefined"));
xasprintf(&tpl, "%s/sfdisk-%s%s", home, name, suffix);
} else
xasprintf(&tpl, "%s-%s%s", filename, name, suffix);
free(buf);
return tpl;
}
static void backup_partition_table(struct sfdisk *sf, const char *devname)
{
const char *name;
@ -300,14 +340,7 @@ static void backup_partition_table(struct sfdisk *sf, const char *devname)
if (!fdisk_has_label(sf->cxt))
return;
if (!sf->backup_file) {
/* initialize default backup filename */
const char *home = getenv ("HOME");
if (!home)
errx(EXIT_FAILURE, _("failed to create a signature backup, $HOME undefined"));
xasprintf(&tpl, "%s/sfdisk-%s-", home, basename(devname));
} else
xasprintf(&tpl, "%s-%s-", sf->backup_file, basename(devname));
tpl = mk_backup_filename_tpl(sf->backup_file, devname, "-");
color_scheme_enable("header", UL_COLOR_BOLD);
fdisk_info(sf->cxt, _("Backup files:"));
@ -321,6 +354,145 @@ static void backup_partition_table(struct sfdisk *sf, const char *devname)
free(tpl);
}
static int move_partition_data(struct sfdisk *sf, size_t partno, struct fdisk_partition *orig_pa)
{
struct fdisk_partition *pa = get_partition(sf->cxt, partno);
char *devname, *typescript;
FILE *f;
int ok = 0, fd, backward;
fdisk_sector_t nsectors, from, to, step, i;
size_t ss, step_bytes, cc;
uintmax_t src, dst;
char *buf;
assert(sf->movedata);
if (!pa)
warnx(_("failed to read new partition from device (ignore --move-data)"));
else if (!fdisk_partition_has_size(pa))
warnx(_("failed to get size of the new partition (ignore --move-data)"));
else if (!fdisk_partition_has_start(pa))
warnx(_("failed to get start of the new partition (ignore --move-data)"));
else if (!fdisk_partition_has_size(orig_pa))
warnx(_("failed to get size of the old partition (ignore --move-data)"));
else if (!fdisk_partition_has_start(orig_pa))
warnx(_("failed to get start of the old partition (ignore --move-data)"));
else if (fdisk_partition_get_start(pa) == fdisk_partition_get_start(orig_pa))
warnx(_("begin of the partition has not been moved (ignore --move-data)"));
else if (fdisk_partition_get_size(orig_pa) < fdisk_partition_get_size(pa))
warnx(_("new partition is smaller than original (ignore --move-data)"));
else
ok = 1;
if (!ok)
return -EINVAL;
fd = fdisk_get_devfd(sf->cxt);
ss = fdisk_get_sector_size(sf->cxt);
nsectors = fdisk_partition_get_size(orig_pa);
from = fdisk_partition_get_start(orig_pa);
to = fdisk_partition_get_start(pa);
backward = from < to;
/* step cannot be bigger than gap between new and old location */
step = from > to ? from - to : to - from;
/* step cannot be bigger than original partition size */
if (step > fdisk_partition_get_size(orig_pa))
step = fdisk_partition_get_size(orig_pa);
/* step cannot be begger than ~1MiB */
if (step > (getpagesize() * 256) / ss)
step = (getpagesize() * 256) / ss;
step_bytes = step * ss;
#if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE)
posix_fadvise(fd, from * ss, nsectors * ss, POSIX_FADV_SEQUENTIAL);
#endif
devname = fdisk_partname(fdisk_get_devname(sf->cxt), partno+1);
typescript = mk_backup_filename_tpl(sf->move_typescript, devname, ".move");
if (!sf->quiet) {
fdisk_info(sf->cxt,"");
color_scheme_enable("header", UL_COLOR_BOLD);
fdisk_info(sf->cxt, _("Data move:"));
color_disable();
fdisk_info(sf->cxt, _(" typescript file: %s"), typescript);
printf(_(" old start: %ju, new start: %ju (move %ju sectors)\n"),
(uintmax_t) from, (uintmax_t) to, nsectors);
fflush(stdout);
}
if (sf->interactive) {
int yes = 0;
fdisk_ask_yesno(sf->cxt, _("Do you want to move partition data?"), &yes);
if (!yes) {
fdisk_info(sf->cxt, _("Leaving."));
return 0;
}
}
f = fopen(typescript, "w");
if (!f)
goto fail;
/* don't translate */
fprintf(f, "# sfdisk: " PACKAGE_STRING "\n");
fprintf(f, "# Disk: %s\n", devname);
fprintf(f, "# Partition: %zu\n", partno + 1);
fprintf(f, "# Operation: move data\n");
fprintf(f, "# Original start offset (in sectors): %ju\n", fdisk_partition_get_start(orig_pa));
fprintf(f, "# New start offset (in sectors): %ju\n", fdisk_partition_get_start(pa));
fprintf(f, "# Area size (in sectors): %ju\n", nsectors);
fprintf(f, "# Step size (in bytes): %zu\n", step_bytes);
fprintf(f, "# Steps: %zu\n", nsectors / step);
fprintf(f, "#\n");
fprintf(f, "# <step>: <from> <to> (step offsets in bytes)\n");
src = (backward ? from + nsectors : from) * ss;
dst = (backward ? to + nsectors : to) * ss;
buf = xmalloc(step_bytes);
/*
fprintf(stderr, ">>>%s: src=%ju, dst=%ju, step=%ju (%ju bytes)\n",
backward ? "backward" : "forward", src, dst, step, step_bytes);
*/
for (cc = 1, i = 0; i < nsectors; i += step, cc++) {
ssize_t rc;
if (backward)
src -= step_bytes, dst -= step_bytes;
lseek(fd, src, SEEK_SET);
rc = read(fd, buf, step_bytes);
if (rc < 0 || rc != (ssize_t) step_bytes)
goto fail;
lseek(fd, dst, SEEK_SET);
rc = write(fd, buf, step_bytes);
if (rc < 0 || rc != (ssize_t) step_bytes)
goto fail;
fsync(fd);
fprintf(f, "%05zu: %12ju %12ju\n", cc, src, dst);
#if defined(POSIX_FADV_DONTNEED) && defined(HAVE_POSIX_FADVISE)
posix_fadvise(fd, src, step_bytes, POSIX_FADV_DONTNEED);
#endif
if (!backward)
src += step_bytes, dst += step_bytes;
}
fclose(f);
free(buf);
free(devname);
free(typescript);
return 0;
fail:
fclose(f);
err(EXIT_FAILURE, _("%s: failed to move data"), devname);
}
static int write_changes(struct sfdisk *sf)
{
int rc = 0;
@ -329,6 +501,8 @@ static int write_changes(struct sfdisk *sf)
fdisk_info(sf->cxt, _("The partition table is unchanged (--no-act)."));
else {
rc = fdisk_write_disklabel(sf->cxt);
if (rc == 0 && sf->movedata && sf->orig_pa)
rc = move_partition_data(sf, sf->partno, sf->orig_pa);
if (!rc) {
fdisk_info(sf->cxt, _("\nThe partition table has been altered."));
fdisk_reread_partition_table(sf->cxt);
@ -1195,6 +1369,8 @@ static int ignore_partition(struct fdisk_partition *pa)
return 0;
}
/*
* sfdisk <device> [[-N] <partno>]
*
@ -1254,6 +1430,9 @@ static int command_fdisk(struct sfdisk *sf, int argc, char **argv)
devname, partno + 1);
created = 1;
next_partno = partno;
if (sf->movedata)
sf->orig_pa = get_partition(sf->cxt, partno);
}
if (sf->append) {
@ -1486,6 +1665,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
fputs(_(" -a, --append append partitions to existing partition table\n"), out);
fputs(_(" -b, --backup backup partition table sectors (see -O)\n"), out);
fputs(_(" --bytes print SIZE in bytes rather than in human readable format\n"), out);
fputs(_(" --move-data[=<typescript>] move partition data after relocation (requires -N)\n"), out);
fputs(_(" -f, --force disable all consistency checking\n"), out);
fputs(_(" --color[=<when>] colorize output (auto, always or never)\n"), out);
fprintf(out,
@ -1533,7 +1713,8 @@ int main(int argc, char *argv[])
OPT_PARTTYPE,
OPT_PARTATTRS,
OPT_BYTES,
OPT_COLOR
OPT_COLOR,
OPT_MOVEDATA,
};
static const struct option longopts[] = {
@ -1554,6 +1735,7 @@ int main(int argc, char *argv[])
{ "list-types", no_argument, NULL, 'T' },
{ "no-act", no_argument, NULL, 'n' },
{ "no-reread", no_argument, NULL, OPT_NOREREAD },
{ "move-data", optional_argument, NULL, OPT_MOVEDATA },
{ "output", required_argument, NULL, 'o' },
{ "partno", required_argument, NULL, 'N' },
{ "reorder", no_argument, NULL, 'r' },
@ -1697,6 +1879,10 @@ int main(int argc, char *argv[])
colormode = colormode_or_err(optarg,
_("unsupported color mode"));
break;
case OPT_MOVEDATA:
sf->movedata = 1;
sf->move_typescript = optarg;
break;
default:
usage(stderr);
}
@ -1716,6 +1902,9 @@ int main(int argc, char *argv[])
else if (!sf->act)
sf->act = ACT_FDISK; /* default */
if (sf->movedata && !(sf->act == ACT_FDISK && sf->partno >= 0))
errx(EXIT_FAILURE, _("--movedata requires -N"));
switch (sf->act) {
case ACT_ACTIVATE:
rc = command_activate(sf, argc - optind, argv + optind);