[12/13] btrfs: check device for critical errors and mark failed
diff mbox

Message ID 1462889372-5274-14-git-send-email-anand.jain@oracle.com
State New
Headers show

Commit Message

Anand Jain May 10, 2016, 2:09 p.m. UTC
From: Anand Jain <Anand.Jain@oracle.com>

Write and Flush errors are considered as critical errors,
upon which the device will be brought offline and marked as
failed. Write and Flush errors are identified using device
error statistics. This is monitored using a kthread
btrfs_health.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Tested-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
---
V6: Fix the case where the fail monitor would clash with user initated
    device operation.

 fs/btrfs/ctree.h   |   2 ++
 fs/btrfs/disk-io.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.c |   1 +
 fs/btrfs/volumes.h |   4 +++
 4 files changed, 107 insertions(+), 1 deletion(-)

Comments

Anand Jain Nov. 8, 2016, 12:18 p.m. UTC | #1
This patch is independent of the hot-space as such.
  11/13 introduced new device state. This patch 12/13
  brings the device to those new device states up on errors.
  Would like to know your opinion on this as well.

Thanks, Anand


On 05/10/16 22:09, Anand Jain wrote:
> From: Anand Jain <Anand.Jain@oracle.com>
>
> Write and Flush errors are considered as critical errors,
> upon which the device will be brought offline and marked as
> failed. Write and Flush errors are identified using device
> error statistics. This is monitored using a kthread
> btrfs_health.
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> Tested-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
> Tested-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com>
> ---
> V6: Fix the case where the fail monitor would clash with user initated
>     device operation.
>
>  fs/btrfs/ctree.h   |   2 ++
>  fs/btrfs/disk-io.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  fs/btrfs/volumes.c |   1 +
>  fs/btrfs/volumes.h |   4 +++
>  4 files changed, 107 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index aa693cfdc9f0..47e9cd9dd29a 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1569,6 +1569,7 @@ struct btrfs_fs_info {
>  	struct mutex tree_log_mutex;
>  	struct mutex transaction_kthread_mutex;
>  	struct mutex cleaner_mutex;
> +	struct mutex health_mutex;
>  	struct mutex chunk_mutex;
>  	struct mutex volume_mutex;
>
> @@ -1686,6 +1687,7 @@ struct btrfs_fs_info {
>  	struct btrfs_workqueue *extent_workers;
>  	struct task_struct *transaction_kthread;
>  	struct task_struct *cleaner_kthread;
> +	struct task_struct *health_kthread;
>  	int thread_pool_size;
>
>  	struct kobject *space_info_kobj;
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index b0648af4951d..8b538443fcd0 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -1876,6 +1876,93 @@ sleep:
>  	return 0;
>  }
>
> +/*
> + * returns:
> + * < 0 : Check didn't run, std error
> + *   0 : No errors found
> + * > 0 : # of devices having fatal errors
> + */
> +static int btrfs_update_devices_health(struct btrfs_root *root)
> +{
> +	int ret = 0;
> +	struct btrfs_device *device;
> +	struct btrfs_fs_info *fs_info = root->fs_info;
> +
> +	if (btrfs_fs_closing(fs_info))
> +		return -EBUSY;
> +
> +	/* mark disk(s) with write or flush error(s) as failed */
> +	mutex_lock(&fs_info->volume_mutex);
> +	list_for_each_entry_rcu(device,
> +			&fs_info->fs_devices->devices, dev_list) {
> +		int c_err;
> +
> +		if (device->failed) {
> +			ret++;
> +			continue;
> +		}
> +
> +		/*
> +		 * todo: replace target device's write/flush error,
> +		 * skip for now
> +		 */
> +		if (device->is_tgtdev_for_dev_replace)
> +			continue;
> +
> +		if (!device->dev_stats_valid)
> +			continue;
> +
> +		c_err = atomic_read(&device->new_critical_errs);
> +		atomic_sub(c_err, &device->new_critical_errs);
> +		if (c_err) {
> +			btrfs_crit_in_rcu(fs_info,
> +				"fatal error on device %s",
> +					rcu_str_deref(device->name));
> +			btrfs_device_enforce_state(device, "failed");
> +			ret ++;
> +		}
> +	}
> +	mutex_unlock(&fs_info->volume_mutex);
> +
> +	return ret;
> +}
> +
> +/*
> + * Devices health maintenance kthread, gets woken-up by transaction
> + * kthread, once sysfs is ready, this should publish the report
> + * through sysfs so that user land scripts and invoke actions.
> + */
> +static int health_kthread(void *arg)
> +{
> +	struct btrfs_root *root = arg;
> +
> +	do {
> +		if (btrfs_need_cleaner_sleep(root))
> +			goto sleep;
> +
> +		if (!mutex_trylock(&root->fs_info->health_mutex))
> +			goto sleep;
> +
> +		if (btrfs_need_cleaner_sleep(root)) {
> +			mutex_unlock(&root->fs_info->health_mutex);
> +			goto sleep;
> +		}
> +
> +		/* Check devices health */
> +		btrfs_update_devices_health(root);
> +
> +		mutex_unlock(&root->fs_info->health_mutex);
> +
> +sleep:
> +		set_current_state(TASK_INTERRUPTIBLE);
> +		if (!kthread_should_stop())
> +			schedule();
> +		__set_current_state(TASK_RUNNING);
> +	} while (!kthread_should_stop());
> +
> +	return 0;
> +}
> +
>  static int transaction_kthread(void *arg)
>  {
>  	struct btrfs_root *root = arg;
> @@ -1922,6 +2009,7 @@ static int transaction_kthread(void *arg)
>  			btrfs_end_transaction(trans, root);
>  		}
>  sleep:
> +		wake_up_process(root->fs_info->health_kthread);
>  		wake_up_process(root->fs_info->cleaner_kthread);
>  		mutex_unlock(&root->fs_info->transaction_kthread_mutex);
>
> @@ -2668,6 +2756,7 @@ int open_ctree(struct super_block *sb,
>  	mutex_init(&fs_info->chunk_mutex);
>  	mutex_init(&fs_info->transaction_kthread_mutex);
>  	mutex_init(&fs_info->cleaner_mutex);
> +	mutex_init(&fs_info->health_mutex);
>  	mutex_init(&fs_info->volume_mutex);
>  	mutex_init(&fs_info->ro_block_group_mutex);
>  	init_rwsem(&fs_info->commit_root_sem);
> @@ -3010,11 +3099,16 @@ retry_root_backup:
>  	if (IS_ERR(fs_info->cleaner_kthread))
>  		goto fail_sysfs;
>
> +	fs_info->health_kthread = kthread_run(health_kthread, tree_root,
> +					       "btrfs-health");
> +	if (IS_ERR(fs_info->health_kthread))
> +		goto fail_cleaner;
> +
>  	fs_info->transaction_kthread = kthread_run(transaction_kthread,
>  						   tree_root,
>  						   "btrfs-transaction");
>  	if (IS_ERR(fs_info->transaction_kthread))
> -		goto fail_cleaner;
> +		goto fail_health;
>
>  	if (!btrfs_test_opt(tree_root, SSD) &&
>  	    !btrfs_test_opt(tree_root, NOSSD) &&
> @@ -3178,6 +3272,10 @@ fail_trans_kthread:
>  	kthread_stop(fs_info->transaction_kthread);
>  	btrfs_cleanup_transaction(fs_info->tree_root);
>  	btrfs_free_fs_roots(fs_info);
> +
> +fail_health:
> +	kthread_stop(fs_info->health_kthread);
> +
>  fail_cleaner:
>  	kthread_stop(fs_info->cleaner_kthread);
>
> @@ -3833,6 +3931,7 @@ void close_ctree(struct btrfs_root *root)
>
>  	kthread_stop(fs_info->transaction_kthread);
>  	kthread_stop(fs_info->cleaner_kthread);
> +	kthread_stop(fs_info->health_kthread);
>
>  	fs_info->closing = 2;
>  	smp_mb();
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 1190e048c7c9..c6aeed73c106 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -233,6 +233,7 @@ static struct btrfs_device *__alloc_device(void)
>  	spin_lock_init(&dev->reada_lock);
>  	atomic_set(&dev->reada_in_flight, 0);
>  	atomic_set(&dev->dev_stats_ccnt, 0);
> +	atomic_set(&dev->new_critical_errs, 0);
>  	btrfs_device_data_ordered_init(dev);
>  	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
>  	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 60eb098d8c76..1ad63ce5d328 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -167,6 +167,7 @@ struct btrfs_device {
>  	/* Counter to record the change of device stats */
>  	atomic_t dev_stats_ccnt;
>  	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
> +	atomic_t new_critical_errs;
>  };
>
>  /*
> @@ -537,6 +538,9 @@ static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
>  	atomic_inc(dev->dev_stat_values + index);
>  	smp_mb__before_atomic();
>  	atomic_inc(&dev->dev_stats_ccnt);
> +	if (index == BTRFS_DEV_STAT_WRITE_ERRS ||
> +		index == BTRFS_DEV_STAT_FLUSH_ERRS)
> +		atomic_inc(&dev->new_critical_errs);
>  }
>
>  static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
>
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David Sterba Nov. 11, 2016, 3:11 p.m. UTC | #2
On Tue, Nov 08, 2016 at 08:18:13PM +0800, Anand Jain wrote:
> 
>   This patch is independent of the hot-space as such.

Independent patches, not to say important fixes, would get the right
attention if they come outside of a large series that introduces a new
feature. Features need time to review so they do not get the priority,
unlike fixes. Even if you send a ping mail to the thread with the
series, it's likely to get lost.

The mail traffic does not decrease over time but we still have the same
time to process it. Making things visible "the right way" really helps,
on both sides.
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Patch
diff mbox

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index aa693cfdc9f0..47e9cd9dd29a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1569,6 +1569,7 @@  struct btrfs_fs_info {
 	struct mutex tree_log_mutex;
 	struct mutex transaction_kthread_mutex;
 	struct mutex cleaner_mutex;
+	struct mutex health_mutex;
 	struct mutex chunk_mutex;
 	struct mutex volume_mutex;
 
@@ -1686,6 +1687,7 @@  struct btrfs_fs_info {
 	struct btrfs_workqueue *extent_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;
+	struct task_struct *health_kthread;
 	int thread_pool_size;
 
 	struct kobject *space_info_kobj;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b0648af4951d..8b538443fcd0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1876,6 +1876,93 @@  sleep:
 	return 0;
 }
 
+/*
+ * returns:
+ * < 0 : Check didn't run, std error
+ *   0 : No errors found
+ * > 0 : # of devices having fatal errors
+ */
+static int btrfs_update_devices_health(struct btrfs_root *root)
+{
+	int ret = 0;
+	struct btrfs_device *device;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+
+	if (btrfs_fs_closing(fs_info))
+		return -EBUSY;
+
+	/* mark disk(s) with write or flush error(s) as failed */
+	mutex_lock(&fs_info->volume_mutex);
+	list_for_each_entry_rcu(device,
+			&fs_info->fs_devices->devices, dev_list) {
+		int c_err;
+
+		if (device->failed) {
+			ret++;
+			continue;
+		}
+
+		/*
+		 * todo: replace target device's write/flush error,
+		 * skip for now
+		 */
+		if (device->is_tgtdev_for_dev_replace)
+			continue;
+
+		if (!device->dev_stats_valid)
+			continue;
+
+		c_err = atomic_read(&device->new_critical_errs);
+		atomic_sub(c_err, &device->new_critical_errs);
+		if (c_err) {
+			btrfs_crit_in_rcu(fs_info,
+				"fatal error on device %s",
+					rcu_str_deref(device->name));
+			btrfs_device_enforce_state(device, "failed");
+			ret ++;
+		}
+	}
+	mutex_unlock(&fs_info->volume_mutex);
+
+	return ret;
+}
+
+/*
+ * Devices health maintenance kthread, gets woken-up by transaction
+ * kthread, once sysfs is ready, this should publish the report
+ * through sysfs so that user land scripts and invoke actions.
+ */
+static int health_kthread(void *arg)
+{
+	struct btrfs_root *root = arg;
+
+	do {
+		if (btrfs_need_cleaner_sleep(root))
+			goto sleep;
+
+		if (!mutex_trylock(&root->fs_info->health_mutex))
+			goto sleep;
+
+		if (btrfs_need_cleaner_sleep(root)) {
+			mutex_unlock(&root->fs_info->health_mutex);
+			goto sleep;
+		}
+
+		/* Check devices health */
+		btrfs_update_devices_health(root);
+
+		mutex_unlock(&root->fs_info->health_mutex);
+
+sleep:
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!kthread_should_stop())
+			schedule();
+		__set_current_state(TASK_RUNNING);
+	} while (!kthread_should_stop());
+
+	return 0;
+}
+
 static int transaction_kthread(void *arg)
 {
 	struct btrfs_root *root = arg;
@@ -1922,6 +2009,7 @@  static int transaction_kthread(void *arg)
 			btrfs_end_transaction(trans, root);
 		}
 sleep:
+		wake_up_process(root->fs_info->health_kthread);
 		wake_up_process(root->fs_info->cleaner_kthread);
 		mutex_unlock(&root->fs_info->transaction_kthread_mutex);
 
@@ -2668,6 +2756,7 @@  int open_ctree(struct super_block *sb,
 	mutex_init(&fs_info->chunk_mutex);
 	mutex_init(&fs_info->transaction_kthread_mutex);
 	mutex_init(&fs_info->cleaner_mutex);
+	mutex_init(&fs_info->health_mutex);
 	mutex_init(&fs_info->volume_mutex);
 	mutex_init(&fs_info->ro_block_group_mutex);
 	init_rwsem(&fs_info->commit_root_sem);
@@ -3010,11 +3099,16 @@  retry_root_backup:
 	if (IS_ERR(fs_info->cleaner_kthread))
 		goto fail_sysfs;
 
+	fs_info->health_kthread = kthread_run(health_kthread, tree_root,
+					       "btrfs-health");
+	if (IS_ERR(fs_info->health_kthread))
+		goto fail_cleaner;
+
 	fs_info->transaction_kthread = kthread_run(transaction_kthread,
 						   tree_root,
 						   "btrfs-transaction");
 	if (IS_ERR(fs_info->transaction_kthread))
-		goto fail_cleaner;
+		goto fail_health;
 
 	if (!btrfs_test_opt(tree_root, SSD) &&
 	    !btrfs_test_opt(tree_root, NOSSD) &&
@@ -3178,6 +3272,10 @@  fail_trans_kthread:
 	kthread_stop(fs_info->transaction_kthread);
 	btrfs_cleanup_transaction(fs_info->tree_root);
 	btrfs_free_fs_roots(fs_info);
+
+fail_health:
+	kthread_stop(fs_info->health_kthread);
+
 fail_cleaner:
 	kthread_stop(fs_info->cleaner_kthread);
 
@@ -3833,6 +3931,7 @@  void close_ctree(struct btrfs_root *root)
 
 	kthread_stop(fs_info->transaction_kthread);
 	kthread_stop(fs_info->cleaner_kthread);
+	kthread_stop(fs_info->health_kthread);
 
 	fs_info->closing = 2;
 	smp_mb();
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1190e048c7c9..c6aeed73c106 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -233,6 +233,7 @@  static struct btrfs_device *__alloc_device(void)
 	spin_lock_init(&dev->reada_lock);
 	atomic_set(&dev->reada_in_flight, 0);
 	atomic_set(&dev->dev_stats_ccnt, 0);
+	atomic_set(&dev->new_critical_errs, 0);
 	btrfs_device_data_ordered_init(dev);
 	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
 	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 60eb098d8c76..1ad63ce5d328 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -167,6 +167,7 @@  struct btrfs_device {
 	/* Counter to record the change of device stats */
 	atomic_t dev_stats_ccnt;
 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
+	atomic_t new_critical_errs;
 };
 
 /*
@@ -537,6 +538,9 @@  static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
 	atomic_inc(dev->dev_stat_values + index);
 	smp_mb__before_atomic();
 	atomic_inc(&dev->dev_stats_ccnt);
+	if (index == BTRFS_DEV_STAT_WRITE_ERRS ||
+		index == BTRFS_DEV_STAT_FLUSH_ERRS)
+		atomic_inc(&dev->new_critical_errs);
 }
 
 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,