[dm-devel] [PATCH] [RFC] [PATCH] Add alias_prefix to get multipath names based on storage type
Malahal Naineni
malahal at us.ibm.com
Wed Jun 23 02:27:33 UTC 2010
The current multipath tools use "mpath" prefix for all LUNs when
user_friendly_names is set. It would be nice if the names are generated
based on the storage subsystem. For example, all EMC LUNs would be named
emc_a, emc_b, elm_c etc., and all IBM's SVC LUNs would be named svc_a,
svc_b, svc_c. This patch attempts to do that using only multipath.conf.
Patches can be added to the internal hardware table, if needed.
Signed-off-by: Malahal Naineni (malahal at us.ibm.com)
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/alias.c
--- a/libmultipath/alias.c Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/alias.c Tue Jun 22 19:25:24 2010 -0700
@@ -180,34 +180,35 @@ fail:
}
static int
-format_devname(char *name, int id, int len)
+format_devname(char *name, int id, int len, char *prefix)
{
int pos;
+ int prefix_len = strlen(prefix);
memset(name,0, len);
- strcpy(name,"mpath");
- for (pos = len - 1; pos >= 5; pos--) {
+ strcpy(name, prefix);
+ for (pos = len - 1; pos >= prefix_len; pos--) {
name[pos] = 'a' + id % 26;
if (id < 26)
break;
id /= 26;
id--;
}
- memmove(name + 5, name + pos, len - pos);
- name[5 + len - pos] = '\0';
- return (5 + len - pos);
+ memmove(name + prefix_len, name + pos, len - pos);
+ name[prefix_len + len - pos] = '\0';
+ return (prefix_len + len - pos);
}
static int
-scan_devname(char *alias)
+scan_devname(char *alias, char *prefix)
{
char *c;
int i, n = 0;
- if (strncmp(alias, "mpath", 5))
+ if (!prefix || strncmp(alias, prefix, strlen(prefix)))
return -1;
- c = alias + 5;
+ c = alias + strlen(prefix);
while (*c != '\0' && *c != ' ' && *c != '\t') {
i = *c - 'a';
n = ( n * 26 ) + i;
@@ -221,7 +222,7 @@ scan_devname(char *alias)
}
static int
-lookup_binding(FILE *f, char *map_wwid, char **map_alias)
+lookup_binding(FILE *f, char *map_wwid, char **map_alias, char *prefix)
{
char buf[LINE_MAX];
unsigned int line_nr = 0;
@@ -240,7 +241,7 @@ lookup_binding(FILE *f, char *map_wwid,
alias = strtok(buf, " \t");
if (!alias) /* blank line */
continue;
- curr_id = scan_devname(alias);
+ curr_id = scan_devname(alias, prefix);
if (curr_id >= id)
id = curr_id + 1;
wwid = strtok(NULL, "");
@@ -284,7 +285,7 @@ rlookup_binding(FILE *f, char **map_wwid
alias = strtok(buf, " \t");
if (!alias) /* blank line */
continue;
- curr_id = scan_devname(alias);
+ curr_id = scan_devname(alias, NULL); /* TBD: Why this call? */
if (curr_id >= id)
id = curr_id + 1;
wwid = strtok(NULL, " \t");
@@ -309,7 +310,7 @@ rlookup_binding(FILE *f, char **map_wwid
}
static char *
-allocate_binding(int fd, char *wwid, int id)
+allocate_binding(int fd, char *wwid, int id, char *prefix)
{
char buf[LINE_MAX];
off_t offset;
@@ -321,7 +322,7 @@ allocate_binding(int fd, char *wwid, int
return NULL;
}
- i = format_devname(buf, id, LINE_MAX);
+ i = format_devname(buf, id, LINE_MAX, prefix);
c = buf + i;
snprintf(c,LINE_MAX - i, " %s\n", wwid);
buf[LINE_MAX - 1] = '\0';
@@ -352,7 +353,7 @@ allocate_binding(int fd, char *wwid, int
}
char *
-get_user_friendly_alias(char *wwid, char *file)
+get_user_friendly_alias(char *wwid, char *file, char *prefix)
{
char *alias;
int fd, scan_fd, id;
@@ -385,7 +386,7 @@ get_user_friendly_alias(char *wwid, char
return NULL;
}
- id = lookup_binding(f, wwid, &alias);
+ id = lookup_binding(f, wwid, &alias, prefix);
if (id < 0) {
fclose(f);
close(scan_fd);
@@ -394,7 +395,7 @@ get_user_friendly_alias(char *wwid, char
}
if (!alias && can_write)
- alias = allocate_binding(fd, wwid, id);
+ alias = allocate_binding(fd, wwid, id, prefix);
fclose(f);
close(scan_fd);
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/alias.h
--- a/libmultipath/alias.h Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/alias.h Tue Jun 22 19:25:24 2010 -0700
@@ -8,5 +8,5 @@
"# alias wwid\n" \
"#\n"
-char *get_user_friendly_alias(char *wwid, char *file);
+char *get_user_friendly_alias(char *wwid, char *file, char *prefix);
char *get_user_friendly_wwid(char *alias, char *file);
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/config.c
--- a/libmultipath/config.c Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/config.c Tue Jun 22 19:25:24 2010 -0700
@@ -158,6 +158,9 @@ free_hwe (struct hwentry * hwe)
if (hwe->prio_args)
FREE(hwe->prio_args);
+ if (hwe->alias_prefix)
+ FREE(hwe->alias_prefix);
+
if (hwe->bl_product)
FREE(hwe->bl_product);
@@ -282,6 +285,7 @@ merge_hwe (struct hwentry * hwe1, struct
merge_str(checker_name);
merge_str(prio_name);
merge_str(prio_args);
+ merge_str(alias_prefix);
merge_str(bl_product);
merge_num(pgpolicy);
merge_num(pgfailback);
@@ -333,6 +337,9 @@ store_hwe (vector hwtable, struct hwentr
if (dhwe->prio_args && !(hwe->prio_args = set_param_str(dhwe->prio_args)))
goto out;
+ if (dhwe->alias_prefix && !(hwe->alias_prefix = set_param_str(dhwe->alias_prefix)))
+ goto out;
+
hwe->pgpolicy = dhwe->pgpolicy;
hwe->pgfailback = dhwe->pgfailback;
hwe->rr_weight = dhwe->rr_weight;
@@ -409,6 +416,9 @@ free_config (struct config * conf)
if (conf->prio_name)
FREE(conf->prio_name);
+ if (conf->alias_prefix)
+ FREE(conf->alias_prefix);
+
if (conf->prio_args)
FREE(conf->prio_args);
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/config.h
--- a/libmultipath/config.h Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/config.h Tue Jun 22 19:25:24 2010 -0700
@@ -25,6 +25,7 @@ struct hwentry {
char * checker_name;
char * prio_name;
char * prio_args;
+ char * alias_prefix;
int pgpolicy;
int pgfailback;
@@ -99,6 +100,7 @@ struct config {
char * prio_name;
char * prio_args;
char * checker_name;
+ char * alias_prefix;
vector keywords;
vector mptable;
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/defaults.h
--- a/libmultipath/defaults.h Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/defaults.h Tue Jun 22 19:25:24 2010 -0700
@@ -2,6 +2,7 @@
#define DEFAULT_UDEVDIR "/dev"
#define DEFAULT_MULTIPATHDIR "/" LIB_STRING "/multipath"
#define DEFAULT_SELECTOR "round-robin 0"
+#define DEFAULT_ALIAS_PREFIX "mpath"
#define DEFAULT_FEATURES "0"
#define DEFAULT_HWHANDLER "0"
#define DEFAULT_MINIO 1000
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/dict.c
--- a/libmultipath/dict.c Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/dict.c Tue Jun 22 19:25:24 2010 -0700
@@ -148,6 +148,17 @@ def_prio_handler(vector strvec)
}
static int
+def_alias_prefix_handler(vector strvec)
+{
+ conf->alias_prefix = set_value(strvec);
+
+ if (!conf->alias_prefix)
+ return 1;
+
+ return 0;
+}
+
+static int
def_prio_args_handler(vector strvec)
{
conf->prio_args = set_value(strvec);
@@ -831,6 +842,22 @@ hw_prio_handler(vector strvec)
}
static int
+hw_alias_prefix_handler(vector strvec)
+{
+ struct hwentry * hwe = VECTOR_LAST_SLOT(conf->hwtable);
+
+ if (!hwe)
+ return 1;
+
+ hwe->alias_prefix = set_value(strvec);
+
+ if (!hwe->alias_prefix)
+ return 1;
+
+ return 0;
+}
+
+static int
hw_prio_args_handler(vector strvec)
{
struct hwentry * hwe = VECTOR_LAST_SLOT(conf->hwtable);
@@ -1580,6 +1607,19 @@ snprint_hw_prio (char * buff, int len, v
}
static int
+snprint_hw_alias_prefix (char * buff, int len, void * data)
+{
+ struct hwentry * hwe = (struct hwentry *)data;
+
+ if (!hwe->alias_prefix || (strlen(hwe->alias_prefix) == 0))
+ return 0;
+ if (conf->alias_prefix && !strcmp(hwe->alias_prefix, conf->alias_prefix))
+ return 0;
+
+ return snprintf(buff, len, "%s", hwe->alias_prefix);
+}
+
+static int
snprint_hw_prio_args (char * buff, int len, void * data)
{
struct hwentry * hwe = (struct hwentry *)data;
@@ -2076,6 +2116,16 @@ snprint_def_user_friendly_names (char *
}
static int
+snprint_def_alias_prefix (char * buff, int len, void * data)
+{
+ if (!conf->alias_prefix)
+ return 0;
+ if (!strcmp(conf->alias_prefix, DEFAULT_ALIAS_PREFIX))
+ return 0;
+ return snprintf(buff, len, conf->alias_prefix);
+}
+
+static int
snprint_ble_simple (char * buff, int len, void * data)
{
struct blentry * ble = (struct blentry *)data;
@@ -2117,6 +2167,7 @@ init_keywords(void)
install_keyword("features", &def_features_handler, &snprint_def_features);
install_keyword("path_checker", &def_path_checker_handler, &snprint_def_path_checker);
install_keyword("checker", &def_path_checker_handler, &snprint_def_path_checker);
+ install_keyword("alias_prefix", &def_alias_prefix_handler, &snprint_def_alias_prefix);
install_keyword("failback", &default_failback_handler, &snprint_def_failback);
install_keyword("rr_min_io", &def_minio_handler, &snprint_def_rr_min_io);
install_keyword("max_fds", &max_fds_handler, &snprint_max_fds);
@@ -2176,6 +2227,7 @@ init_keywords(void)
install_keyword("path_selector", &hw_selector_handler, &snprint_hw_selector);
install_keyword("path_checker", &hw_path_checker_handler, &snprint_hw_path_checker);
install_keyword("checker", &hw_path_checker_handler, &snprint_hw_path_checker);
+ install_keyword("alias_prefix", &hw_alias_prefix_handler, &snprint_hw_alias_prefix);
install_keyword("features", &hw_features_handler, &snprint_hw_features);
install_keyword("hardware_handler", &hw_handler_handler, &snprint_hw_hardware_handler);
install_keyword("prio", &hw_prio_handler, &snprint_hw_prio);
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/propsel.c
--- a/libmultipath/propsel.c Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/propsel.c Tue Jun 22 19:25:24 2010 -0700
@@ -215,6 +215,26 @@ select_selector (struct multipath * mp)
return 0;
}
+static void
+select_alias_prefix (struct multipath * mp)
+{
+ if (mp->hwe && mp->hwe->alias_prefix) {
+ mp->alias_prefix = mp->hwe->alias_prefix;
+ condlog(3, "%s: alias_prefix = %s (controller setting)",
+ mp->wwid, mp->alias_prefix);
+ return;
+ }
+ if (conf->alias_prefix) {
+ mp->alias_prefix = conf->alias_prefix;
+ condlog(3, "%s: alias_prefix = %s (config file default)",
+ mp->wwid, mp->alias_prefix);
+ return;
+ }
+ mp->alias_prefix = set_default(DEFAULT_ALIAS_PREFIX);
+ condlog(3, "%s: alias_prefix = %s (internal default)",
+ mp->wwid, mp->alias_prefix);
+}
+
extern int
select_alias (struct multipath * mp)
{
@@ -222,9 +242,11 @@ select_alias (struct multipath * mp)
mp->alias = mp->mpe->alias;
else {
mp->alias = NULL;
- if (conf->user_friendly_names)
+ if (conf->user_friendly_names) {
+ select_alias_prefix(mp);
mp->alias = get_user_friendly_alias(mp->wwid,
- conf->bindings_file);
+ conf->bindings_file, mp->alias_prefix);
+ }
if (mp->alias == NULL){
char *alias;
if ((alias = MALLOC(WWID_SIZE)) != NULL){
diff -r 49b7dc2c9d46 -r b4d519b4bbc6 libmultipath/structs.h
--- a/libmultipath/structs.h Tue Jun 15 17:23:49 2010 -0700
+++ b/libmultipath/structs.h Tue Jun 22 19:25:24 2010 -0700
@@ -186,6 +186,7 @@ struct multipath {
/* configlet pointers */
char * alias;
+ char * alias_prefix;
char * selector;
char * features;
char * hwhandler;
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