Call zvol_create_minors() in spa_open_common() when initializing pool

There is an extremely odd bug that causes zvols to fail to appear on
some systems, but not others. Recently, I was able to consistently
reproduce this issue over a period of 1 month. The issue disappeared
after I applied this change from FreeBSD.

This is from FreeBSD's pool version 28 import, which occurred in
revision 219089.

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #441
Issue #599

diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index e986e92..65f78b7 100644 (file)
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -64,6 +64,7 @@
 #include <sys/zfs_ioctl.h>
 #include <sys/dsl_scan.h>
 #include <sys/zfeature.h>
+#include <sys/zvol.h>
 
 #ifdef _KERNEL
 #include <sys/bootprops.h>
@@ -2856,6 +2857,7 @@ spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
        spa_load_state_t state = SPA_LOAD_OPEN;
        int error;
        int locked = B_FALSE;
+       int firstopen = B_FALSE;
 
        *spapp = NULL;
 
@@ -2879,6 +2881,8 @@ spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
        if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
                zpool_rewind_policy_t policy;
 
+               firstopen = B_TRUE;
+
                zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
                    &policy);
                if (policy.zrp_request & ZPOOL_DO_REWIND)
@@ -2953,6 +2957,11 @@ spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
                mutex_exit(&spa_namespace_lock);
        }
 
+#ifdef _KERNEL
+       if (firstopen)
+               zvol_create_minors(spa->spa_name);
+#endif
+
        *spapp = spa;
 
        return (0);
@@ -4010,6 +4019,10 @@ spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
        mutex_exit(&spa_namespace_lock);
        spa_history_log_version(spa, LOG_POOL_IMPORT);
 
+#ifdef _KERNEL
+       zvol_create_minors(pool);
+#endif
+
        return (0);
 }
 

diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 1226b2c..a9184a1 100644 (file)
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -1268,9 +1268,6 @@ zfs_ioc_pool_import(zfs_cmd_t *zc)
                        error = err;
        }
 
-       if (error == 0)
-               zvol_create_minors(zc->zc_name);
-
        nvlist_free(config);
 
        if (props)