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>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index f5406766ece32146adf0f13abdf18978c769c4cc..b79e7472a9b30c1eb90863995e811d490c7fb32e 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -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)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index adf851a081bd512f1a12fed3df76cfde6acec975..5e0090ef4182e71de26afec04d23edb19b3f4e39 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -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 @@ fail:
        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.");

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 03516c7f5be1e5d3eeb770972c26eb0b7faf3a56..259ce99302fcaa94381f2768ddb2938e999a1358 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -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;

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 4427e04540516ef006e08ce8de95bebc23516905..3fa1f3d90ce0e21cb3ba27fa98d3201252f91f8e 100644 (file)
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -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.