[PATCH] btrfs-progs: Add dev uuid output for print_dev_item().

[PATCH] btrfs-progs: Add dev uuid output for print_dev_item().

[Qu Wenruo]

The original print_dev_item() only prints device id,total bytes and
bytes used.
When it comes to debug things related to duplicated device id, dev uuid
is needed to distinguish different device since device is is no
reliable.

This patch added dev uuid output.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 print-tree.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/print-tree.c b/print-tree.c
index 574ae9e..cb5c2e1 100644
--- a/print-tree.c
+++ b/print-tree.c
@@ -179,11 +179,20 @@ void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
 static void print_dev_item(struct extent_buffer *eb,
 			   struct btrfs_dev_item *dev_item)
 {
+	char disk_uuid_c[BTRFS_UUID_UNPARSED_SIZE];
+	u8 disk_uuid[BTRFS_UUID_SIZE];
+
+	read_extent_buffer(eb, disk_uuid,
+			   (unsigned long)btrfs_device_uuid(dev_item),
+			   BTRFS_UUID_SIZE);
+	uuid_unparse(disk_uuid, disk_uuid_c);
 	printf("\t\tdev item devid %llu "
-	       "total_bytes %llu bytes used %Lu\n",
+	       "total_bytes %llu bytes used %Lu\n"
+	       "\t\tdev uuid %s\n",
 	       (unsigned long long)btrfs_device_id(eb, dev_item),
 	       (unsigned long long)btrfs_device_total_bytes(eb, dev_item),
-	       (unsigned long long)btrfs_device_bytes_used(eb, dev_item));
+	       (unsigned long long)btrfs_device_bytes_used(eb, dev_item),
+	       disk_uuid_c);
 }
 
 static void print_uuids(struct extent_buffer *eb)
-- 
1.9.3

Re: [PATCH] btrfs-progs: Add dev uuid output for print_dev_item().

[Mike Fleetwood]

On 29 May 2014 02:02, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote:
> The original print_dev_item() only prints device id,total bytes and
> bytes used.
> When it comes to debug things related to duplicated device id, dev uuid
> is needed to distinguish different device since device is is no
> reliable.

At the end of the message I think there is a couple of typos and you meant:
... device id is not reliable.

>
> This patch added dev uuid output.
>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>  print-tree.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)

Thanks,
Mike

Re: [PATCH] btrfs-progs: Add dev uuid output for print_dev_item().

[Qu Wenruo]

-------- Original Message --------
Subject: Re: [PATCH] btrfs-progs: Add dev uuid output for print_dev_item().
From: Mike Fleetwood <mike.fleetwood@googlemail.com>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date: 2014年05月30日 03:52
> On 29 May 2014 02:02, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote:
>> The original print_dev_item() only prints device id,total bytes and
>> bytes used.
>> When it comes to debug things related to duplicated device id, dev uuid
>> is needed to distinguish different device since device is is no
>> reliable.
> At the end of the message I think there is a couple of typos and you meant:
> ... device id is not reliable.
Yes, it is not reliable when comes to reappered missing devices.
If you mounted btrfs with missing device using degraded mode and 
replaced missing device,
but the missing device reappered, then devices with same dev uuid will 
show up.

Thanks,
Qu
>
>> This patch added dev uuid output.
>>
>> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
>> ---
>>   print-tree.c | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
> Thanks,
> Mike
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Re: [PATCH] btrfs-progs: Add dev uuid output for print_dev_item().

[David Sterba]

On Thu, May 29, 2014 at 08:52:04PM +0100, Mike Fleetwood wrote:
> On 29 May 2014 02:02, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote:
> > The original print_dev_item() only prints device id,total bytes and
> > bytes used.
> > When it comes to debug things related to duplicated device id, dev uuid
> > is needed to distinguish different device since device is is no
> > reliable.
> 
> At the end of the message I think there is a couple of typos and you meant:
> ... device id is not reliable.

Fixed, thanks.