diff options
| author | Darik Horn <[email protected]> | 2012-06-01 20:49:10 -0500 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2012-06-13 17:05:16 -0700 |
| commit | 74497b7ab6af69434453e03c755d3f6e6e655aee (patch) | |
| tree | 69c6d2068536df39f2a45e58de7deb427f0db2af /module/zfs/zvol.c | |
| parent | bc98d6c80944dcd920d1147e6bff2192e886a2f5 (diff) | |
Add zvol_inhibit_dev module option.
ZoL can create more zvols at runtime than can be configured during
system start, which hangs the init stack at reboot.
When a slow system has more than a few hundred zvols, udev will
fork bomb during system start and spend too much time in device
detection routines, so upstart kills it.
The zfs_inhibit_dev option allows an affected system to be rescued
by skipping /dev/zd* creation and thereby avoiding the udev
overload. All zvols are made inaccessible if this option is set, but
the `zfs destroy` and `zfs send` commands still work, and ZFS
filesystems can be mounted.
Signed-off-by: Brian Behlendorf <[email protected]>
Diffstat (limited to 'module/zfs/zvol.c')
| -rw-r--r-- | module/zfs/zvol.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c index ba26543f7..125d58de9 100644 --- a/module/zfs/zvol.c +++ b/module/zfs/zvol.c @@ -46,6 +46,7 @@ #include <sys/zvol.h> #include <linux/blkdev_compat.h> +unsigned int zvol_inhibit_dev = 0; unsigned int zvol_major = ZVOL_MAJOR; unsigned int zvol_threads = 32; @@ -1341,6 +1342,9 @@ zvol_create_minors(const char *pool) spa_t *spa = NULL; int error = 0; + if (zvol_inhibit_dev) + return (0); + mutex_enter(&zvol_state_lock); if (pool) { error = dmu_objset_find_spa(NULL, pool, zvol_create_minors_cb, @@ -1370,6 +1374,9 @@ zvol_remove_minors(const char *pool) zvol_state_t *zv, *zv_next; char *str; + if (zvol_inhibit_dev) + return; + str = kmem_zalloc(MAXNAMELEN, KM_SLEEP); if (pool) { (void) strncpy(str, pool, strlen(pool)); @@ -1431,6 +1438,9 @@ zvol_fini(void) list_destroy(&zvol_state_list); } +module_param(zvol_inhibit_dev, uint, 0644); +MODULE_PARM_DESC(zvol_inhibit_dev, "Do not create zvol device nodes"); + module_param(zvol_major, uint, 0444); MODULE_PARM_DESC(zvol_major, "Major number for zvol device"); |