[PATCH 0/2] fix device orders consistency

[PATCH 0/2] fix device orders consistency

[Anand Jain]

By maintaining the device order (some) consistency it makes reproducing
the problem more consistent.

Anand Jain (2):
  btrfs: fix device order consistency
  btrfs: fix alloc device order consistency

 fs/btrfs/volumes.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

-- 
2.15.0

[PATCH 1/2] btrfs: fix device order consistency

[Anand Jain]

By maintaining the device order consistency it makes reproducing
the problem more consistent. So fix this by having the devices
sorted by some order within the kernel, lets say by devid.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/volumes.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d393808071d5..68be58a5b03f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -27,6 +27,7 @@
 #include <linux/raid/pq.h>
 #include <linux/semaphore.h>
 #include <linux/uuid.h>
+#include <linux/list_sort.h>
 #include <asm/div64.h>
 #include "ctree.h"
 #include "extent_map.h"
@@ -1108,6 +1109,20 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 	return ret;
 }
 
+static int device_sort(void *priv, struct list_head *a, struct list_head *b)
+{
+	struct btrfs_device *dev1, *dev2;
+
+	dev1 = list_entry(a, struct btrfs_device, dev_list);
+	dev2 = list_entry(b, struct btrfs_device, dev_list);
+
+	if (dev1->devid < dev2->devid)
+		return -1;
+	else if (dev1->devid > dev2->devid)
+		return 1;
+	return 0;
+}
+
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder)
 {
@@ -1118,6 +1133,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		fs_devices->opened++;
 		ret = 0;
 	} else {
+		list_sort(NULL, &fs_devices->devices, device_sort);
 		ret = __btrfs_open_devices(fs_devices, flags, holder);
 	}
 	mutex_unlock(&uuid_mutex);
-- 
2.15.0

[PATCH 2/2] btrfs: fix alloc device order consistency

[Anand Jain]

Add opened device to the tail of dev_alloc_list so that it maintains
the same order as dev_list.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/volumes.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 68be58a5b03f..543c166049e7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -713,7 +713,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
 		fs_devices->rw_devices++;
-		list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
+		list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list);
 	}
 	brelse(bh);
 
-- 
2.15.0

Re: [PATCH 1/2] btrfs: fix device order consistency

[Nikolay Borisov]

On 18.01.2018 04:32, Anand Jain wrote:
> By maintaining the device order consistency it makes reproducing
> the problem more consistent. So fix this by having the devices

Which problem is that ?

> sorted by some order within the kernel, lets say by devid.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  fs/btrfs/volumes.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index d393808071d5..68be58a5b03f 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -27,6 +27,7 @@
>  #include <linux/raid/pq.h>
>  #include <linux/semaphore.h>
>  #include <linux/uuid.h>
> +#include <linux/list_sort.h>
>  #include <asm/div64.h>
>  #include "ctree.h"
>  #include "extent_map.h"
> @@ -1108,6 +1109,20 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>  	return ret;
>  }
>  
> +static int device_sort(void *priv, struct list_head *a, struct list_head *b)
> +{
> +	struct btrfs_device *dev1, *dev2;
> +
> +	dev1 = list_entry(a, struct btrfs_device, dev_list);
> +	dev2 = list_entry(b, struct btrfs_device, dev_list);
> +
> +	if (dev1->devid < dev2->devid)
> +		return -1;
> +	else if (dev1->devid > dev2->devid)
> +		return 1;
> +	return 0;
> +}
> +
>  int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>  		       fmode_t flags, void *holder)
>  {
> @@ -1118,6 +1133,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>  		fs_devices->opened++;
>  		ret = 0;
>  	} else {
> +		list_sort(NULL, &fs_devices->devices, device_sort);
>  		ret = __btrfs_open_devices(fs_devices, flags, holder);
>  	}
>  	mutex_unlock(&uuid_mutex);
> 

Re: [PATCH 1/2] btrfs: fix device order consistency

[Anand Jain]

On 01/18/2018 04:32 PM, Nikolay Borisov wrote:
> 
> 
> On 18.01.2018 04:32, Anand Jain wrote:
>> By maintaining the device order consistency it makes reproducing
>> the problem more consistent. So fix this by having the devices
> 
> Which problem is that ?

  I noticed when trying to reproduce raid1 missed writes issue
  (xfstests test case is coming up). This is good to have as
  such with any device related issue.

Thanks, Anand

>> sorted by some order within the kernel, lets say by devid.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>>   fs/btrfs/volumes.c | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index d393808071d5..68be58a5b03f 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -27,6 +27,7 @@
>>   #include <linux/raid/pq.h>
>>   #include <linux/semaphore.h>
>>   #include <linux/uuid.h>
>> +#include <linux/list_sort.h>
>>   #include <asm/div64.h>
>>   #include "ctree.h"
>>   #include "extent_map.h"
>> @@ -1108,6 +1109,20 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>>   	return ret;
>>   }
>>   
>> +static int device_sort(void *priv, struct list_head *a, struct list_head *b)
>> +{
>> +	struct btrfs_device *dev1, *dev2;
>> +
>> +	dev1 = list_entry(a, struct btrfs_device, dev_list);
>> +	dev2 = list_entry(b, struct btrfs_device, dev_list);
>> +
>> +	if (dev1->devid < dev2->devid)
>> +		return -1;
>> +	else if (dev1->devid > dev2->devid)
>> +		return 1;
>> +	return 0;
>> +}
>> +
>>   int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>>   		       fmode_t flags, void *holder)
>>   {
>> @@ -1118,6 +1133,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
>>   		fs_devices->opened++;
>>   		ret = 0;
>>   	} else {
>> +		list_sort(NULL, &fs_devices->devices, device_sort);
>>   		ret = __btrfs_open_devices(fs_devices, flags, holder);
>>   	}
>>   	mutex_unlock(&uuid_mutex);
>>