[lvm-devel] master - dmsetup: Add --concise to dmsetup create.
Alasdair Kergon
agk at sourceware.org
Fri Aug 4 18:40:57 UTC 2017
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=827be01758ec5adb7b9d5ea75b658092adc65534
Commit: 827be01758ec5adb7b9d5ea75b658092adc65534
Parent: e6afe9e7820da5d5086dbcf82532bb9d0daafb00
Author: Alasdair G Kergon <agk at redhat.com>
AuthorDate: Fri Aug 4 19:38:34 2017 +0100
Committer: Alasdair G Kergon <agk at redhat.com>
CommitterDate: Fri Aug 4 19:38:34 2017 +0100
dmsetup: Add --concise to dmsetup create.
Add the new concise format to dmsetup create, either as a single
command-line parameter or from stdin.
Based on patches submitted by
Enric Balletbo i Serra <enric.balletbo at collabora.com>.
---
WHATS_NEW_DM | 1 +
man/dmsetup.8_main | 72 +++++++++++++++-
tools/dmsetup.c | 253 ++++++++++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 316 insertions(+), 10 deletions(-)
diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index 514973b..d3cc78c 100644
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
Version 1.02.143 -
=================================
+ Add --concise to dmsetup create for many devices with tables in one command.
Accept minor number without major in library when it knows dm major number.
Introduce single-line concise table output format: dmsetup table --concise
diff --git a/man/dmsetup.8_main b/man/dmsetup.8_main
index c218f6c..1e778ad 100644
--- a/man/dmsetup.8_main
+++ b/man/dmsetup.8_main
@@ -36,6 +36,17 @@ dmsetup \(em low level logical volume management
.
.HP
.B dmsetup
+.de CMD_CREATE_CONCISE
+. ad l
+. BR create
+. BR --concise
+. RI [ concise_device_specification ]
+. ad b
+..
+.CMD_CREATE_CONCISE
+.
+.HP
+.B dmsetup
.de CMD_DEPS
. ad l
. BR deps
@@ -621,6 +632,16 @@ device the node \fI/dev/mapper/device_name\fP is created.
See below for more information on the table format.
.
.HP
+.CMD_CREATE_CONCISE
+.br
+Creates one or more devices from a concise device specification.
+Each device is specified by a comma-separated list: name, uuid, minor number, flags, comma-separated table lines.
+Flags defaults to read-write (rw) or may be read-only (ro).
+Uuid, minor number and flags are optional so those fields may be empty.
+A semi-colon separates specifications of different devices.
+Use a backslash to escape the following character, for example a comma or semi-colon in a name or table. See also CONCISE FORMAT below.
+.
+.HP
.CMD_DEPS
.br
Outputs a list of devices referenced by the live table for the specified
@@ -828,7 +849,7 @@ displayed always.
With \fB--concise\fP, the output is presented concisely on a single line.
Commas then separate the name, uuid, minor device number, flags ('ro' or 'rw')
and the table (if present). Semi-colons separate devices. Backslashes escape
-any commas, semi-colons or backslashes.
+any commas, semi-colons or backslashes. See CONCISE FORMAT below.
.
.HP
.CMD_TARGETS
@@ -1001,6 +1022,55 @@ documentation directory for the device-mapper package.)
.br
2056320 2875602 linear /dev/hdb 1028160
.
+.SH CONCISE FORMAT
+.
+A concise representation of one of more devices.
+.sp
+.br
+- A comma separates the fields of each device.
+.br
+- A semi-colon separates devices.
+.TP
+The representation of a device takes the form:
+.sp
+<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<dev_name>,<uuid>,<minor>,<flags>,<table>[,<table>+]]
+.TP
+The fields are:
+.
+.TP
+.B name
+The name of the device.
+.TP
+.B uuid
+The UUID of the device (or empty).
+.TP
+.B minor
+The minor number of the device. If empty, the kernel assigns a suitable minor number.
+.TP
+.B flags
+Supported flags are:
+.sp
+.B ro
+Sets the table being loaded for the device read-only
+.br
+.B rw
+Sets the table being loaded for the device read-write (default)
+.TP
+.B table
+One line of the table. See TABLE FORMAT above.
+.
+.SH EXAMPLES
+.
+# A simple linear read-only device
+.br
+test-linear-small,,,ro,0 2097152 linear /dev/loop0 0, 2097152 2097152 linear /dev/loop1 0
+.br
+.sp
+# Two linear devices
+.br
+test-linear-small,,,,0 2097152 linear /dev/loop0 0;test-linear-large,,,, 0 2097152 linear /dev/loop1 0, 2097152 2097152 linear /dev/loop2 0
+.br
+.
.SH ENVIRONMENT VARIABLES
.
.TP
diff --git a/tools/dmsetup.c b/tools/dmsetup.c
index e92ba17..0fd2f2c 100644
--- a/tools/dmsetup.c
+++ b/tools/dmsetup.c
@@ -359,6 +359,23 @@ static int _parse_line(struct dm_task *dmt, char *buffer, const char *file,
return 1;
}
+/* Parse multiple lines of table */
+static int _parse_table_lines(struct dm_task *dmt)
+{
+ char *pos = _table, *next_pos;
+ int line = 0;
+
+ do {
+ /* Identify and terminate each line */
+ if ((next_pos = strchr(_table, '\n')))
+ *next_pos++ = '\0';
+ if (!_parse_line(dmt, pos, "", ++line))
+ return_0;
+ } while ((pos = next_pos));
+
+ return 1;
+}
+
static int _parse_file(struct dm_task *dmt, const char *file)
{
char *buffer = NULL;
@@ -366,9 +383,9 @@ static int _parse_file(struct dm_task *dmt, const char *file)
FILE *fp;
int r = 0, line = 0;
- /* one-line table on cmdline */
+ /* Table on cmdline or from stdin with --concise */
if (_table)
- return _parse_line(dmt, _table, "", ++line);
+ return _parse_table_lines(dmt);
/* OK for empty stdin */
if (file) {
@@ -1098,21 +1115,17 @@ out:
return r;
}
-static int _create(CMD_ARGS)
+static int _create_one_device(const char *name, const char *file)
{
int r = 0;
struct dm_task *dmt;
- const char *file = NULL;
uint32_t cookie = 0;
uint16_t udev_flags = 0;
- if (argc == 2)
- file = argv[1];
-
if (!(dmt = dm_task_create(DM_DEVICE_CREATE)))
return_0;
- if (!dm_task_set_name(dmt, argv[0]))
+ if (!dm_task_set_name(dmt, name))
goto_out;
if (_switches[UUID_ARG] && !dm_task_set_uuid(dmt, _uuid))
@@ -1187,6 +1200,221 @@ out:
return r;
}
+#define DEFAULT_BUF_SIZE 4096
+
+static char *_slurp_stdin(void)
+{
+ char *buf, *pos;
+ size_t bufsize = DEFAULT_BUF_SIZE;
+ size_t total = 0;
+ ssize_t n = 0;
+
+ if (!(buf = dm_malloc(bufsize))) {
+ log_error("Buffer memory allocation failed.");
+ return NULL;
+ }
+
+ pos = buf;
+ do {
+ do
+ n = read(STDIN_FILENO, pos, (size_t) bufsize - total - 1);
+ while ((n < 0) && ((errno == EINTR) || (errno == EAGAIN)));
+
+ if (n < 0) {
+ log_error("Read from stdin aborted: %s", strerror(errno));
+ dm_free(buf);
+ return NULL;
+ }
+
+ if (!n)
+ break;
+
+ total += n;
+ pos += n;
+ if (total == bufsize - 1) {
+ bufsize *= 2;
+ if (!(buf = dm_realloc(buf, bufsize))) {
+ log_error("Buffer memory extension to %" PRIsize_t " bytes failed.", bufsize);
+ return NULL;
+ }
+ }
+ } while (1);
+
+ buf[total] = '\0';
+
+ return buf;
+}
+
+static int _create_concise(const struct command *cmd, int argc, char **argv)
+{
+ char *concise_format;
+ char *c, *n;
+ char *fields[5] = { NULL }; /* name,uuid,minor,flags,table */
+ int f = 0;
+
+ if (_switches[TABLE_ARG] || _switches[MINOR_ARG] || _switches[UUID_ARG] ||
+ _switches[NOTABLE_ARG] || _switches[INACTIVE_ARG]){
+ log_error("--concise is incompatible with --[no]table, --minor, --uuid and --inactive.");
+ return 0;
+ }
+
+ if (argc)
+ concise_format = argv[0];
+ else if (!(concise_format = _slurp_stdin()))
+ return_0;
+
+ /* Work through input string c, parsing into sets of 5 fields. */
+ /* Strip out any characters quoted by backslashes in-place. */
+ /* Read characters from c and prepare them in situ for final processing at n */
+ c = n = fields[f] = concise_format;
+
+ while (*c) {
+ /* Quoted character? Skip past quote. */
+ if (*c == '\\') {
+ if (!*(++c)) {
+ log_error("Backslash must be followed by another character at end of string.");
+ *n = '\0';
+ log_error("Parsed %d fields: name: %s uuid: %s minor: %s flags: %s table: %s",
+ f + 1, fields[0], fields[1], fields[2], fields[3], fields[4]);
+ goto out;
+ }
+
+ /* Don't interpret next character */
+ *n++ = *c++;
+
+ continue;
+ }
+
+ /* Comma marking end of field? */
+ if (*c == ',' && f < 4) {
+ /* Terminate string */
+ *n++ = '\0', c++;
+
+ /* Store start of next field */
+ fields[++f] = n;
+
+ /* Skip any whitespace after field-separating commas */
+ while(isspace(*c))
+ c++;
+
+ continue;
+ }
+
+ /* Comma marking end of a table line? */
+ if (*c == ',' && f >= 4) {
+ /* Replace comma with newline to match standard table input format */
+ *n++ = '\n', c++;
+
+ continue;
+ }
+
+ /* Semi-colon marking end of device? */
+ if (*c == ';' || *(c + 1) == '\0') {
+ /* End of input? */
+ if (*c != ';')
+ /* Copy final character */
+ *n++ = *c;
+
+ /* Terminate string */
+ *n++ = '\0', c++;
+
+ if (f != 4) {
+ log_error("Five comma-separated fields are required for each device");
+ log_error("Parsed %d fields: name: %s uuid: %s minor: %s flags: %s table: %s",
+ f + 1, fields[0], fields[1], fields[2], fields[3], fields[4]);
+ goto out;
+ }
+
+ /* Set up parameters the same way as when specified directly on command line */
+ if (*fields[1]) {
+ _switches[UUID_ARG] = 1;
+ _uuid = fields[1];
+ }
+
+ if (*fields[2]) {
+ _switches[MINOR_ARG] = 1;
+ _int_args[MINOR_ARG] = atoi(fields[2]);
+ }
+
+ if (!strcmp(fields[3], "ro"))
+ _switches[READ_ONLY] = 1;
+ else if (*fields[3] && strcmp(fields[3], "rw")) {
+ log_error("Invalid flags parameter '%s' must be 'ro' or 'rw' or empty.", fields[3]);
+ _uuid = NULL;
+ goto out;
+ }
+
+ _table = fields[4];
+
+ /* Create the device */
+ if (!_create_one_device(fields[0], NULL)) {
+ _uuid = _table = NULL;
+ goto out;
+ }
+
+ /* Clear parameters ready for any further devices */
+ _switches[UUID_ARG] = 0;
+ _switches[MINOR_ARG] = 0;
+ _switches[READ_ONLY] = 0;
+ _uuid = _table = NULL;
+
+ f = 0;
+ fields[0] = n;
+ fields[1] = fields[2] = fields[3] = fields[4] = NULL;
+
+ /* Skip any whitespace after semi-colons */
+ while(isspace(*c))
+ c++;
+
+ continue;
+ }
+
+ /* Normal character */
+ *n++ = *c++;
+ }
+
+ if (fields[0] != n) {
+ *n = '\0';
+ log_error("Incomplete entry: five comma-separated fields are required for each device");
+ log_error("Parsed %d fields: name: %s uuid: %s minor: %s flags: %s table: %s",
+ f + 1, fields[0], fields[1], fields[2], fields[3], fields[4]);
+ goto out;
+ }
+
+ return 1;
+
+out:
+ if (!argc)
+ dm_free(concise_format);
+
+ return 0;
+}
+
+static int _create(CMD_ARGS)
+{
+ const char *name;
+ const char *file = NULL;
+
+ if (_switches[CONCISE_ARG]) {
+ if (argc > 1) {
+ log_error("dmsetup create --concise takes at most one argument");
+ return 0;
+ }
+ return _create_concise(cmd, argc, argv);
+ }
+
+ if (!argc) {
+ log_error("Please provide a name for the new device.");
+ return 0;
+ }
+
+ name = argv[0];
+ if (argc == 2)
+ file = argv[1];
+
+ return _create_one_device(name, file);
+}
+
static int _do_rename(const char *name, const char *new_name, const char *new_uuid) {
int r = 0;
struct dm_task *dmt;
@@ -2148,6 +2376,7 @@ static int _status(CMD_ARGS)
name = names->name;
else {
if (!argc && !_switches[UUID_ARG] && !_switches[MAJOR_ARG])
+ /* FIXME Respect deps in concise mode, so they are correctly ordered for recreation */
return _process_all(cmd, NULL, argc, argv, 0, _status);
name = argv[0];
}
@@ -5930,7 +6159,8 @@ 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"
+ "\tcreate --concise [<concise_device_spec_list>]", 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},
@@ -6022,6 +6252,11 @@ static void _dmsetup_usage(FILE *out)
"-j <major> -m <minor>\n");
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, "<concise_device_specification> has single-device entries separated by semi-colons:\n"
+ " <name>,<uuid>,<minor>,<flags>,<table>\n"
+ " where <flags> is 'ro' or 'rw' (the default) and any of <uuid>, <minor>\n"
+ " and <flags> may be empty. Separate extra table lines with commas.\n"
+ " E.g.: dev1,,,,0 100 linear 253:1 0,100 100 error;dev2,,,ro,0 1 error\n");
fprintf(out, "Table_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"
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