The null_blk driver has multiple driver-specific fault injection
mechanisms. Each fault injection configuration can only be specified by a
module parameter and cannot be reconfigured without reloading the driver.
Also, each configuration is common to all devices and is initialized every
time a new device is added.
This change adds the following subdirectories for each null_blk device.
/sys/kernel/config/nullb/<disk>/timeout_inject
/sys/kernel/config/nullb/<disk>/requeue_inject
/sys/kernel/config/nullb/<disk>/init_hctx_fault_inject
Each fault injection attribute can be dynamically set per device by a
corresponding file in these directories.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
---
.../fault-injection/fault-injection.rst | 8 ++
drivers/block/null_blk/Kconfig | 2 +-
drivers/block/null_blk/main.c | 93 ++++++++++++++-----
drivers/block/null_blk/null_blk.h | 7 +-
4 files changed, 87 insertions(+), 23 deletions(-)
diff --git a/Documentation/fault-injection/fault-injection.rst b/Documentation/fault-injection/fault-injection.rst
index 08e420e10973..b64809514b0f 100644
--- a/Documentation/fault-injection/fault-injection.rst
+++ b/Documentation/fault-injection/fault-injection.rst
@@ -52,6 +52,14 @@ Available fault injection capabilities
status code is NVME_SC_INVALID_OPCODE with no retry. The status code and
retry flag can be set via the debugfs.
+- Null test block driver fault injection
+
+ inject IO timeouts by setting config items under
+ /sys/kernel/config/nullb/<disk>/timeout_inject,
+ inject requeue requests by setting config items under
+ /sys/kernel/config/nullb/<disk>/requeue_inject, and
+ inject init_hctx() errors by setting config items under
+ /sys/kernel/config/nullb/<disk>/init_hctx_fault_inject.
Configure fault-injection capabilities behavior
-----------------------------------------------
diff --git a/drivers/block/null_blk/Kconfig b/drivers/block/null_blk/Kconfig
index 6bf1f8ca20a2..ff23bb9346d0 100644
--- a/drivers/block/null_blk/Kconfig
+++ b/drivers/block/null_blk/Kconfig
@@ -9,4 +9,4 @@ config BLK_DEV_NULL_BLK
config BLK_DEV_NULL_BLK_FAULT_INJECTION
bool "Support fault injection for Null test block driver"
- depends on BLK_DEV_NULL_BLK && FAULT_INJECTION
+ depends on BLK_DEV_NULL_BLK && FAULT_INJECTION_CONFIGFS
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 9e6b032c8ecc..fd3a9cf2ea92 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -250,7 +250,7 @@ static void null_free_device_storage(struct nullb_device *dev, bool is_cache);
static inline struct nullb_device *to_nullb_device(struct config_item *item)
{
- return item ? container_of(item, struct nullb_device, item) : NULL;
+ return item ? container_of(to_config_group(item), struct nullb_device, group) : NULL;
}
static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page)
@@ -593,8 +593,29 @@ static const struct config_item_type nullb_device_type = {
.ct_owner = THIS_MODULE,
};
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
+
+static void nullb_add_fault_config(struct nullb_device *dev)
+{
+ fault_config_init(&dev->timeout_config, "timeout_inject");
+ fault_config_init(&dev->requeue_config, "requeue_inject");
+ fault_config_init(&dev->init_hctx_fault_config, "init_hctx_fault_inject");
+
+ configfs_add_default_group(&dev->timeout_config.group, &dev->group);
+ configfs_add_default_group(&dev->requeue_config.group, &dev->group);
+ configfs_add_default_group(&dev->init_hctx_fault_config.group, &dev->group);
+}
+
+#else
+
+static void nullb_add_fault_config(struct nullb_device *dev)
+{
+}
+
+#endif
+
static struct
-config_item *nullb_group_make_item(struct config_group *group, const char *name)
+config_group *nullb_group_make_group(struct config_group *group, const char *name)
{
struct nullb_device *dev;
@@ -605,9 +626,10 @@ config_item *nullb_group_make_item(struct config_group *group, const char *name)
if (!dev)
return ERR_PTR(-ENOMEM);
- config_item_init_type_name(&dev->item, name, &nullb_device_type);
+ config_group_init_type_name(&dev->group, name, &nullb_device_type);
+ nullb_add_fault_config(dev);
- return &dev->item;
+ return &dev->group;
}
static void
@@ -645,7 +667,7 @@ static struct configfs_attribute *nullb_group_attrs[] = {
};
static struct configfs_group_operations nullb_group_ops = {
- .make_item = nullb_group_make_item,
+ .make_group = nullb_group_make_group,
.drop_item = nullb_group_drop_item,
};
@@ -676,6 +698,13 @@ static struct nullb_device *null_alloc_dev(void)
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return NULL;
+
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
+ dev->timeout_config.attr = null_timeout_attr;
+ dev->requeue_config.attr = null_requeue_attr;
+ dev->init_hctx_fault_config.attr = null_init_hctx_attr;
+#endif
+
INIT_RADIX_TREE(&dev->data, GFP_ATOMIC);
INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC);
if (badblocks_init(&dev->badblocks, 0)) {
@@ -1529,24 +1558,48 @@ static void null_submit_bio(struct bio *bio)
null_handle_cmd(alloc_cmd(nq, bio), sector, nr_sectors, bio_op(bio));
}
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
+
+static bool should_timeout_request(struct request *rq)
+{
+ struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
+ struct nullb_device *dev = cmd->nq->dev;
+
+ return should_fail(&dev->timeout_config.attr, 1);
+}
+
+static bool should_requeue_request(struct request *rq)
+{
+ struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
+ struct nullb_device *dev = cmd->nq->dev;
+
+ return should_fail(&dev->requeue_config.attr, 1);
+}
+
+static bool should_init_hctx_fail(struct nullb_device *dev)
+{
+ return should_fail(&dev->init_hctx_fault_config.attr, 1);
+}
+
+#else
+
static bool should_timeout_request(struct request *rq)
{
-#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
- if (g_timeout_str[0])
- return should_fail(&null_timeout_attr, 1);
-#endif
return false;
}
static bool should_requeue_request(struct request *rq)
{
-#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
- if (g_requeue_str[0])
- return should_fail(&null_requeue_attr, 1);
-#endif
return false;
}
+static bool should_init_hctx_fail(struct nullb_device *dev)
+{
+ return false;
+}
+
+#endif
+
static void null_map_queues(struct blk_mq_tag_set *set)
{
struct nullb *nullb = set->driver_data;
@@ -1743,10 +1796,8 @@ static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data,
struct nullb *nullb = hctx->queue->queuedata;
struct nullb_queue *nq;
-#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
- if (g_init_hctx_str[0] && should_fail(&null_init_hctx_attr, 1))
+ if (should_init_hctx_fail(nullb->dev))
return -EFAULT;
-#endif
nq = &nullb->queues[hctx_idx];
hctx->driver_data = nq;
@@ -2066,9 +2117,6 @@ static int null_add_dev(struct nullb_device *dev)
if (rv)
goto out_cleanup_queues;
- if (!null_setup_fault())
- goto out_cleanup_tags;
-
nullb->tag_set->timeout = 5 * HZ;
nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb);
if (IS_ERR(nullb->disk)) {
@@ -2130,10 +2178,10 @@ static int null_add_dev(struct nullb_device *dev)
null_config_discard(nullb);
- if (config_item_name(&dev->item)) {
+ if (config_item_name(&dev->group.cg_item)) {
/* Use configfs dir name as the device name */
snprintf(nullb->disk_name, sizeof(nullb->disk_name),
- "%s", config_item_name(&dev->item));
+ "%s", config_item_name(&dev->group.cg_item));
} else {
sprintf(nullb->disk_name, "nullb%d", nullb->index);
}
@@ -2233,6 +2281,9 @@ static int __init null_init(void)
g_home_node = NUMA_NO_NODE;
}
+ if (!null_setup_fault())
+ return -EINVAL;
+
if (g_queue_mode == NULL_Q_RQ) {
pr_err("legacy IO path is no longer available\n");
return -EINVAL;
diff --git a/drivers/block/null_blk/null_blk.h b/drivers/block/null_blk/null_blk.h
index eb5972c50be8..929f659dd255 100644
--- a/drivers/block/null_blk/null_blk.h
+++ b/drivers/block/null_blk/null_blk.h
@@ -69,7 +69,12 @@ enum {
struct nullb_device {
struct nullb *nullb;
- struct config_item item;
+ struct config_group group;
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
+ struct fault_config timeout_config;
+ struct fault_config requeue_config;
+ struct fault_config init_hctx_fault_config;
+#endif
struct radix_tree_root data; /* data stored in the disk */
struct radix_tree_root cache; /* disk cache data */
unsigned long flags; /* device flags */
--
2.34.1
