[linux-lvm] [PATCH 1/2] dmsetup: add support to output devices in bootformat style

[Enric Balletbo i Serra]

Add a new parameter to be able to output the bootformat of one or more
devices. The bootformat for a device can be obtained by doing a:

dmsetup table <device...> --bootformat

where device can be a specific device, a list of the devices or empty
for all devices. The output will look like this:

<dev_name>,<uuid>,<mode>,<table>[,<table>+][;<dev_name>,<uuid>,<mode>,<table>[,<table>+]]+

Signed-off-by: Enric Balletbo i Serra <***@collabora.com>
---
tools/dmsetup.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/tools/dmsetup.c b/tools/dmsetup.c
index 5c5c14c..fc99145 100644
--- a/tools/dmsetup.c
+++ b/tools/dmsetup.c
@@ -163,6 +163,7 @@ enum {
AREA_ARG,
AREAS_ARG,
AREA_SIZE_ARG,
+ BOOTFORMAT_ARG,
BOUNDS_ARG,
CHECKS_ARG,
CLEAR_ARG,
@@ -2127,6 +2128,9 @@ static int _status(CMD_ARGS)
int matched = 0;
int ls_only = 0;
struct dm_info info;
+ const char *uuid = NULL;
+ char bootstr[LINE_SIZE] = {0};
+ int len;

if (names)
name = names->name;
@@ -2171,6 +2175,9 @@ static int _status(CMD_ARGS)
if (!name)
name = dm_task_get_name(dmt);

+ if (!uuid)
+ uuid = dm_task_get_uuid(dmt);
+
/* Fetch targets and print 'em */
do {
next = dm_get_next_target(dmt, next, &start, &length,
@@ -2184,6 +2191,20 @@ static int _status(CMD_ARGS)
_switches[VERBOSE_ARG])
_display_dev(dmt, name);
next = NULL;
+ } else if (_switches[BOOTFORMAT_ARG]) {
+ if (!dm_snprintf(bootstr, sizeof(bootstr), "%s,%s,%s",
+ dm_task_get_name(dmt), uuid,
+ info.read_only ? "ro" : "rw"))
+ goto_out;
+ if (target_type) {
+ len = strlen(bootstr);
+ if (!dm_snprintf(bootstr + len,
+ sizeof(bootstr) - len,
+ "," FMTu64 " " FMTu64 " %s %s",
+ start, length, target_type,
+ params))
+ goto_out;
+ }
} else if (!_switches[EXEC_ARG] || !_command_to_exec ||
_switches[VERBOSE_ARG]) {
if (!matched && _switches[VERBOSE_ARG])
@@ -2218,6 +2239,9 @@ static int _status(CMD_ARGS)
matched = 1;
} while (next);

+ if (matched && _switches[BOOTFORMAT_ARG])
+ printf("%s;", bootstr);
+
if (multiple_devices && _switches[VERBOSE_ARG] && matched && !ls_only)
putchar('\n');

@@ -5903,7 +5927,9 @@ static struct command _dmsetup_commands[] = {
{"deps", "[-o <options>] [<device>...]", 0, -1, 1, 0, _deps},
{"stats", "<command> [<options>] [<device>...]", 1, -1, 1, 1, _stats},
{"status", "[<device>...] [--noflush] [--target <target_type>]", 0, -1, 1, 0, _status},
- {"table", "[<device>...] [--target <target_type>] [--showkeys]", 0, -1, 1, 0, _status},
+ {"table", "[<device>...]\n"
+ "\t [--target <target_type>] [--showkeys]\n"
+ "\t [--bootformat]", 0, -1, 1, 0, _status},
{"wait", "<device> [<event_nr>] [--noflush]", 0, 2, 0, 0, _wait},
{"mknodes", "[<device>...]", 0, -1, 1, 0, _mknodes},
{"mangle", "[<device>...]", 0, -1, 1, 0, _mangle},
@@ -6468,6 +6494,7 @@ static int _process_switches(int *argcp, char ***argvp, const char *dev_dir)
{"area", 0, &ind, AREA_ARG},
{"areas", 1, &ind, AREAS_ARG},
{"areasize", 1, &ind, AREA_SIZE_ARG},
+ {"bootformat", 0, &ind, BOOTFORMAT_ARG},
{"bounds", 1, &ind, BOUNDS_ARG},
{"checks", 0, &ind, CHECKS_ARG},
{"clear", 0, &ind, CLEAR_ARG},
@@ -6636,6 +6663,8 @@ static int _process_switches(int *argcp, char ***argvp, const char *dev_dir)
return_0;
if (c == 'h' || ind == HELP_ARG)
_switches[HELP_ARG]++;
+ if (ind == BOOTFORMAT_ARG)
+ _switches[BOOTFORMAT_ARG]++;
if (ind == BOUNDS_ARG) {
_switches[BOUNDS_ARG]++;
_string_args[BOUNDS_ARG] = optarg;

[Enric Balletbo i Serra]

Add a new switch to supply a bootformated string to dmsetup, we
support create one or multiple devices in one line provided to
the create command. E.g.

dmsetup create --bootformat <multi_dev_info>|<multi_dev_info_file>

Signed-off-by: Enric Balletbo i Serra <***@collabora.com>
---
tools/dmsetup.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 123 insertions(+), 1 deletion(-)

diff --git a/tools/dmsetup.c b/tools/dmsetup.c
index fc99145..0961e65 100644
--- a/tools/dmsetup.c
+++ b/tools/dmsetup.c
@@ -1097,6 +1097,116 @@ out:
return r;
}

+static int _parse_device(char *dev_info)
+{
+ int r = 0;
+ struct dm_task *dmt;
+ uint32_t cookie = 0;
+ uint16_t udev_flags = 0;
+ int line = 0, field = 0;
+ char *str = dev_info, *ptr = dev_info;
+
+ if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
+ return_0;
+
+ /*
+ * FIXME: support embedded '\,' in string data:
+ * s/strsep/_find_unescaped_comma()/
+ */
+ while ((str = strsep(&ptr, ",")) != NULL ) {
+ switch (field) {
+ case 0: /* set device name */
+ if (!dm_task_set_name(dmt, str))
+ goto_out;
+ break;
+ case 1: /* set uuid if any */
+ if (strlen(str) && !dm_task_set_uuid(dmt, str))
+ goto_out;
+ break;
+ case 2:
+ if (!strncmp(str, "rw", strlen(str)))
+ break;
+ /* set as read-only if flags = "ro" | "" */
+ if (!strncmp(str, "ro", strlen(str)) ||
+ !strncmp(str, "", strlen(str))) {
+ if (!dm_task_set_ro(dmt))
+ goto_out;
+ } else
+ goto_out;
+ break;
+ default:
+ if (!_parse_line(dmt, str, "", line++))
+ goto_out;
+ break;
+ }
+ field++;
+ }
+
+ if (field < 4)
+ goto_out;
+
+ if (!_set_task_add_node(dmt))
+ goto_out;
+
+ if (_udev_cookie)
+ cookie = _udev_cookie;
+
+ if (_udev_only)
+ udev_flags |= DM_UDEV_DISABLE_LIBRARY_FALLBACK;
+
+ if (!dm_task_set_cookie(dmt, &cookie, udev_flags) ||
+ !_task_run(dmt))
+ goto_out;
+
+ r = 1;
+
+out:
+ if (!_udev_cookie)
+ (void) dm_udev_wait(cookie);
+
+ if (r && _switches[VERBOSE_ARG])
+ r = _display_info(dmt);
+
+ dm_task_destroy(dmt);
+
+ return r;
+}
+
+static int _create_multi_devices(const char *multi_dev_info)
+{
+ char *buffer = NULL, *dev_info, *ptr;
+ size_t buffer_size = LINE_SIZE;
+ int r = 0;
+
+ if (!(buffer = dm_malloc(buffer_size))) {
+ err("Failed to malloc line buffer.");
+ return 0;
+ }
+
+ if (!multi_dev_info) { /* get info from stdin */
+ if (!(getline(&buffer, &buffer_size, stdin) > 0))
+ goto_out;
+ } else if (!dm_strncpy(buffer, multi_dev_info, LINE_SIZE))
+ goto_out;
+
+ dev_info = ptr = buffer;
+
+ /*
+ * FIXME: support embedded '\;' in string data:
+ * s/strsep/_find_unescaped_semicolon()/
+ */
+ while ((dev_info = strsep(&ptr, ";")) != NULL )
+ if (!_parse_device(dev_info))
+ goto_out;
+
+ r = 1;
+out:
+ memset(buffer, 0, buffer_size);
+ dm_free(buffer);
+
+ return r;
+}
+
static int _create(CMD_ARGS)
{
int r = 0;
@@ -1105,6 +1215,16 @@ static int _create(CMD_ARGS)
uint32_t cookie = 0;
uint16_t udev_flags = 0;

+ /* arguments are in bootformat style */
+ if (_switches[BOOTFORMAT_ARG]) {
+ if (argc > 1)
+ return 0;
+ if (argc == 1)
+ file = argv[0];
+ return _create_multi_devices(file);
+ }
+
+ /* otherwise */
if (argc == 2)
file = argv[1];

@@ -5909,7 +6029,8 @@ static struct command _dmsetup_commands[] = {
"\t [-U|--uid <uid>] [-G|--gid <gid>] [-M|--mode <octal_mode>]\n"
"\t [-u|uuid <uuid>] [--addnodeonresume|--addnodeoncreate]\n"
"\t [--readahead {[+]<sectors>|auto|none}]\n"
- "\t [-n|--notable|--table {<table>|<table_file>}]", 1, 2, 0, 0, _create},
+ "\t [-n|--notable|--table {<table>|<table_file>}]\n"
+ "\t [--bootformat {<multi_dev_info>|<multi_dev_info_file>}]", 0, 2, 0, 0, _create},
{"remove", "[--deferred] [-f|--force] [--retry] <device>...", 0, -1, 1, 0, _remove},
{"remove_all", "[-f|--force]", 0, 0, 0, 0, _remove_all},
{"suspend", "[--noflush] [--nolockfs] <device>...", 0, -1, 1, 0, _suspend},
@@ -6004,6 +6125,7 @@ static void _dmsetup_usage(FILE *out)
fprintf(out, "<mangling_mode> is one of 'none', 'auto' and 'hex'.\n");
fprintf(out, "<fields> are comma-separated. Use 'help -c' for list.\n");
fprintf(out, "Table_file contents may be supplied on stdin.\n");
+ fprintf(out, "Multi_dev_info_file contents may be supplied on stdin.\n");
fprintf(out, "Options are: devno, devname, blkdevname.\n");
fprintf(out, "Tree specific options are: ascii, utf, vt100; compact, inverted, notrunc;\n"
" blkdevname, [no]device, active, open, rw and uuid.\n");

[Alasdair G Kergon]

I've adapted the way this patch interacts with the various other permitted
command line options and committed it.

Post by Enric Balletbo i Serra
dmsetup table <device...> --bootformat

I went for --concise in the end, as I expect it will have wider uses than just
booting.

Alasdair