diff options
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 554bf213c043..6cc6dd74c153 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -174,6 +174,16 @@ static const struct block_device_operations md_fops; static int start_readonly; +/* + * The original mechanism for creating an md device is to create + * a device node in /dev and to open it. This causes races with device-close. + * The preferred method is to write to the "new_array" module parameter. + * This can avoid races. + * Setting create_on_open to false disables the original mechanism + * so all the races disappear. + */ +static bool create_on_open = true; + /* bio_clone_mddev * like bio_clone, but with a local bio set */ @@ -5285,7 +5295,8 @@ static int md_alloc(dev_t dev, char *name) static struct kobject *md_probe(dev_t dev, int *part, void *data) { - md_alloc(dev, NULL); + if (create_on_open) + md_alloc(dev, NULL); return NULL; } @@ -9200,6 +9211,7 @@ static int set_ro(const char *val, struct kernel_param *kp) module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR); module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR); module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR); +module_param(create_on_open, bool, S_IRUSR|S_IWUSR); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("MD RAID framework"); |