dm table: share target argument parsing functions

Move multipath target argument parsing code into dm-table so other
targets can share it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mike Snitzer 2011-08-02 12:32:04 +01:00 committed by Alasdair G Kergon
parent a6e50b409d
commit 498f0103ea
4 changed files with 147 additions and 112 deletions

View File

@ -30,7 +30,6 @@
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "crypt"
#define MESG_STR(x) x, sizeof(x)
/*
* context holding the current state of a multi-part conversion
@ -1770,12 +1769,12 @@ static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
if (argc < 2)
goto error;
if (!strnicmp(argv[0], MESG_STR("key"))) {
if (!strcasecmp(argv[0], "key")) {
if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
DMWARN("not suspended during key manipulation.");
return -EINVAL;
}
if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) {
if (argc == 3 && !strcasecmp(argv[1], "set")) {
ret = crypt_set_key(cc, argv[2]);
if (ret)
return ret;
@ -1783,7 +1782,7 @@ static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
ret = cc->iv_gen_ops->init(cc);
return ret;
}
if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) {
if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
ret = cc->iv_gen_ops->wipe(cc);
if (ret)

View File

@ -22,7 +22,6 @@
#include <linux/atomic.h>
#define DM_MSG_PREFIX "multipath"
#define MESG_STR(x) x, sizeof(x)
#define DM_PG_INIT_DELAY_MSECS 2000
#define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1)
@ -505,80 +504,29 @@ static void trigger_event(struct work_struct *work)
* <#paths> <#per-path selector args>
* [<path> [<arg>]* ]+ ]+
*---------------------------------------------------------------*/
struct param {
unsigned min;
unsigned max;
char *error;
};
static int read_param(struct param *param, char *str, unsigned *v, char **error)
{
if (!str ||
(sscanf(str, "%u", v) != 1) ||
(*v < param->min) ||
(*v > param->max)) {
*error = param->error;
return -EINVAL;
}
return 0;
}
struct arg_set {
unsigned argc;
char **argv;
};
static char *shift(struct arg_set *as)
{
char *r;
if (as->argc) {
as->argc--;
r = *as->argv;
as->argv++;
return r;
}
return NULL;
}
static void consume(struct arg_set *as, unsigned n)
{
BUG_ON (as->argc < n);
as->argc -= n;
as->argv += n;
}
static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg,
struct dm_target *ti)
{
int r;
struct path_selector_type *pst;
unsigned ps_argc;
static struct param _params[] = {
static struct dm_arg _args[] = {
{0, 1024, "invalid number of path selector args"},
};
pst = dm_get_path_selector(shift(as));
pst = dm_get_path_selector(dm_shift_arg(as));
if (!pst) {
ti->error = "unknown path selector type";
return -EINVAL;
}
r = read_param(_params, shift(as), &ps_argc, &ti->error);
r = dm_read_arg_group(_args, as, &ps_argc, &ti->error);
if (r) {
dm_put_path_selector(pst);
return -EINVAL;
}
if (ps_argc > as->argc) {
dm_put_path_selector(pst);
ti->error = "not enough arguments for path selector";
return -EINVAL;
}
r = pst->create(&pg->ps, ps_argc, as->argv);
if (r) {
dm_put_path_selector(pst);
@ -587,12 +535,12 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
}
pg->ps.type = pst;
consume(as, ps_argc);
dm_consume_args(as, ps_argc);
return 0;
}
static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps,
struct dm_target *ti)
{
int r;
@ -609,7 +557,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
if (!p)
return ERR_PTR(-ENOMEM);
r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table),
r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table),
&p->path.dev);
if (r) {
ti->error = "error getting device";
@ -660,16 +608,16 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
return ERR_PTR(r);
}
static struct priority_group *parse_priority_group(struct arg_set *as,
static struct priority_group *parse_priority_group(struct dm_arg_set *as,
struct multipath *m)
{
static struct param _params[] = {
static struct dm_arg _args[] = {
{1, 1024, "invalid number of paths"},
{0, 1024, "invalid number of selector args"}
};
int r;
unsigned i, nr_selector_args, nr_params;
unsigned i, nr_selector_args, nr_args;
struct priority_group *pg;
struct dm_target *ti = m->ti;
@ -693,26 +641,26 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
/*
* read the paths
*/
r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error);
r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error);
if (r)
goto bad;
r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error);
r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error);
if (r)
goto bad;
nr_params = 1 + nr_selector_args;
nr_args = 1 + nr_selector_args;
for (i = 0; i < pg->nr_pgpaths; i++) {
struct pgpath *pgpath;
struct arg_set path_args;
struct dm_arg_set path_args;
if (as->argc < nr_params) {
if (as->argc < nr_args) {
ti->error = "not enough path parameters";
r = -EINVAL;
goto bad;
}
path_args.argc = nr_params;
path_args.argc = nr_args;
path_args.argv = as->argv;
pgpath = parse_path(&path_args, &pg->ps, ti);
@ -723,7 +671,7 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
pgpath->pg = pg;
list_add_tail(&pgpath->list, &pg->pgpaths);
consume(as, nr_params);
dm_consume_args(as, nr_args);
}
return pg;
@ -733,28 +681,23 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
return ERR_PTR(r);
}
static int parse_hw_handler(struct arg_set *as, struct multipath *m)
static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
{
unsigned hw_argc;
int ret;
struct dm_target *ti = m->ti;
static struct param _params[] = {
static struct dm_arg _args[] = {
{0, 1024, "invalid number of hardware handler args"},
};
if (read_param(_params, shift(as), &hw_argc, &ti->error))
if (dm_read_arg_group(_args, as, &hw_argc, &ti->error))
return -EINVAL;
if (!hw_argc)
return 0;
if (hw_argc > as->argc) {
ti->error = "not enough arguments for hardware handler";
return -EINVAL;
}
m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
request_module("scsi_dh_%s", m->hw_handler_name);
if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
ti->error = "unknown hardware handler type";
@ -778,7 +721,7 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m)
for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1)
j = sprintf(p, "%s", as->argv[i]);
}
consume(as, hw_argc - 1);
dm_consume_args(as, hw_argc - 1);
return 0;
fail:
@ -787,52 +730,45 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m)
return ret;
}
static int parse_features(struct arg_set *as, struct multipath *m)
static int parse_features(struct dm_arg_set *as, struct multipath *m)
{
int r;
unsigned argc;
struct dm_target *ti = m->ti;
const char *param_name;
const char *arg_name;
static struct param _params[] = {
static struct dm_arg _args[] = {
{0, 5, "invalid number of feature args"},
{1, 50, "pg_init_retries must be between 1 and 50"},
{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
};
r = read_param(_params, shift(as), &argc, &ti->error);
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return -EINVAL;
if (!argc)
return 0;
if (argc > as->argc) {
ti->error = "not enough arguments for features";
return -EINVAL;
}
do {
param_name = shift(as);
arg_name = dm_shift_arg(as);
argc--;
if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) {
if (!strcasecmp(arg_name, "queue_if_no_path")) {
r = queue_if_no_path(m, 1, 0);
continue;
}
if (!strnicmp(param_name, MESG_STR("pg_init_retries")) &&
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = read_param(_params + 1, shift(as),
&m->pg_init_retries, &ti->error);
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
argc--;
continue;
}
if (!strnicmp(param_name, MESG_STR("pg_init_delay_msecs")) &&
if (!strcasecmp(arg_name, "pg_init_delay_msecs") &&
(argc >= 1)) {
r = read_param(_params + 2, shift(as),
&m->pg_init_delay_msecs, &ti->error);
r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error);
argc--;
continue;
}
@ -847,15 +783,15 @@ static int parse_features(struct arg_set *as, struct multipath *m)
static int multipath_ctr(struct dm_target *ti, unsigned int argc,
char **argv)
{
/* target parameters */
static struct param _params[] = {
/* target arguments */
static struct dm_arg _args[] = {
{0, 1024, "invalid number of priority groups"},
{0, 1024, "invalid initial priority group number"},
};
int r;
struct multipath *m;
struct arg_set as;
struct dm_arg_set as;
unsigned pg_count = 0;
unsigned next_pg_num;
@ -876,11 +812,11 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
if (r)
goto bad;
r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error);
r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error);
if (r)
goto bad;
r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error);
r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error);
if (r)
goto bad;
@ -1510,10 +1446,10 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
}
if (argc == 1) {
if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) {
if (!strcasecmp(argv[0], "queue_if_no_path")) {
r = queue_if_no_path(m, 1, 0);
goto out;
} else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) {
} else if (!strcasecmp(argv[0], "fail_if_no_path")) {
r = queue_if_no_path(m, 0, 0);
goto out;
}
@ -1524,18 +1460,18 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
goto out;
}
if (!strnicmp(argv[0], MESG_STR("disable_group"))) {
if (!strcasecmp(argv[0], "disable_group")) {
r = bypass_pg_num(m, argv[1], 1);
goto out;
} else if (!strnicmp(argv[0], MESG_STR("enable_group"))) {
} else if (!strcasecmp(argv[0], "enable_group")) {
r = bypass_pg_num(m, argv[1], 0);
goto out;
} else if (!strnicmp(argv[0], MESG_STR("switch_group"))) {
} else if (!strcasecmp(argv[0], "switch_group")) {
r = switch_pg_num(m, argv[1]);
goto out;
} else if (!strnicmp(argv[0], MESG_STR("reinstate_path")))
} else if (!strcasecmp(argv[0], "reinstate_path"))
action = reinstate_path;
else if (!strnicmp(argv[0], MESG_STR("fail_path")))
else if (!strcasecmp(argv[0], "fail_path"))
action = fail_path;
else {
DMWARN("Unrecognised multipath message received.");

View File

@ -797,6 +797,63 @@ int dm_table_add_target(struct dm_table *t, const char *type,
return r;
}
/*
* Target argument parsing helpers.
*/
static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error, unsigned grouped)
{
const char *arg_str = dm_shift_arg(arg_set);
if (!arg_str ||
(sscanf(arg_str, "%u", value) != 1) ||
(*value < arg->min) ||
(*value > arg->max) ||
(grouped && arg_set->argc < *value)) {
*error = arg->error;
return -EINVAL;
}
return 0;
}
int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 0);
}
EXPORT_SYMBOL(dm_read_arg);
int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 1);
}
EXPORT_SYMBOL(dm_read_arg_group);
const char *dm_shift_arg(struct dm_arg_set *as)
{
char *r;
if (as->argc) {
as->argc--;
r = *as->argv;
as->argv++;
return r;
}
return NULL;
}
EXPORT_SYMBOL(dm_shift_arg);
void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
{
BUG_ON(as->argc < num_args);
as->argc -= num_args;
as->argv += num_args;
}
EXPORT_SYMBOL(dm_consume_args);
static int dm_table_set_type(struct dm_table *t)
{
unsigned i;

View File

@ -208,6 +208,49 @@ struct dm_target_callbacks {
int dm_register_target(struct target_type *t);
void dm_unregister_target(struct target_type *t);
/*
* Target argument parsing.
*/
struct dm_arg_set {
unsigned argc;
char **argv;
};
/*
* The minimum and maximum value of a numeric argument, together with
* the error message to use if the number is found to be outside that range.
*/
struct dm_arg {
unsigned min;
unsigned max;
char *error;
};
/*
* Validate the next argument, either returning it as *value or, if invalid,
* returning -EINVAL and setting *error.
*/
int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error);
/*
* Process the next argument as the start of a group containing between
* arg->min and arg->max further arguments. Either return the size as
* *num_args or, if invalid, return -EINVAL and set *error.
*/
int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *num_args, char **error);
/*
* Return the current argument and shift to the next.
*/
const char *dm_shift_arg(struct dm_arg_set *as);
/*
* Move through num_args arguments.
*/
void dm_consume_args(struct dm_arg_set *as, unsigned num_args);
/*-----------------------------------------------------------------
* Functions for creating and manipulating mapped devices.
* Drop the reference with dm_put when you finish with the object.