[PATCH v3 (Only) 1/3] btrfs-progs: map-logical: look at next leaf if slot > items

[PATCH v3 (Only) 1/3] btrfs-progs: map-logical: look at next leaf if slot > items

[james harvey]

btrfs-map-logical -l 10955980800 -b 4096 <path>
No extent found at range [10955980800,10955984896)

But, this extent exists.  btrfs-debug-tree shows:

   item 202 key (10955976704 EXTENT_ITEM 4096) itemoff 8772 itemsize 37
           refs 1 gen 62656 flags DATA
           shared data backref parent 142655488 count 1
...
   item 0 key (10955980800 EXTENT_ITEM 4096) itemoff 16246 itemsize 37
           refs 1 gen 62656 flags DATA
           shared data backref parent 128958464 count 1

The code searches for (logical, 0, 0), and looks forward then backward.  It
needs to go to the next leaf when slot > number of items on this leaf.

Signed-off-by: James Harvey <jamespharvey20@gmail.com>
---
 btrfs-map-logical.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/btrfs-map-logical.c b/btrfs-map-logical.c
index 7a8bcff9..8a4228a4 100644
--- a/btrfs-map-logical.c
+++ b/btrfs-map-logical.c
@@ -65,6 +65,14 @@ static int map_one_extent(struct btrfs_fs_info *fs_info,
        BUG_ON(ret == 0);
        ret = 0;

+       if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+               ret = btrfs_next_leaf(fs_info->extent_root, path);
+               if (ret > 0)
+                       ret = -ENOENT;
+               if (ret)
+                       goto out;
+       }
+
 again:
        btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
        if ((search_foward && key.objectid < logical) ||
--
2.17.0

Re: [PATCH v3 (Only) 2/3] btrfs-progs: map-logical: Use btrfs_next_extent_item()

[james harvey]

On Thu, Jun 7, 2018 at 4:50 AM, Su Yue <suy.fnst@cn.fujitsu.com> wrote:
> On 06/07/2018 03:20 PM, james harvey wrote:
>>
>> btrfs_next_extent_item() looks for BTRFS_EXTENT_ITEM_KEY and
>> BTRFS_METADATA_KEY,
>> which are the types we're looking for.
>>
>> Signed-off-by: James Harvey <jamespharvey20@gmail.com>
>
> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>

btrfs_next_extent_item() looks for BTRFS_EXTENT_ITEM_KEY and BTRFS_METADATA_KEY,
which are the types we're looking for.

(Previous versions missed last 0 argument to btrfs_next_extent_item().  Sorry, I
realize I need to take more time before sending, being more careful on
everything.)

Signed-off-by: James Harvey <jamespharvey20@gmail.com>
---
 btrfs-map-logical.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/btrfs-map-logical.c b/btrfs-map-logical.c
index 2451012b..8a41b037 100644
--- a/btrfs-map-logical.c
+++ b/btrfs-map-logical.c
@@ -83,7 +83,8 @@ again:
                        ret = btrfs_previous_extent_item(fs_info->extent_root,
                                                         path, 0);
                else
-                       ret = btrfs_next_item(fs_info->extent_root, path);
+                       ret = btrfs_next_extent_item(fs_info->extent_root,
+                                                    path, 0);
                if (ret)
                        goto out;
                goto again;
--
2.17.0

Re: [PATCH v3 (Only) 2/3] btrfs-progs: map-logical: Use btrfs_next_extent_item()

[Su Yue]

On 06/08/2018 02:41 AM, james harvey wrote:
> On Thu, Jun 7, 2018 at 4:50 AM, Su Yue <suy.fnst@cn.fujitsu.com> wrote:
>> On 06/07/2018 03:20 PM, james harvey wrote:
>>>
>>> btrfs_next_extent_item() looks for BTRFS_EXTENT_ITEM_KEY and
>>> BTRFS_METADATA_KEY,
>>> which are the types we're looking for.
>>>
>>> Signed-off-by: James Harvey <jamespharvey20@gmail.com>
>>
>> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
> 
> btrfs_next_extent_item() looks for BTRFS_EXTENT_ITEM_KEY and BTRFS_METADATA_KEY,
> which are the types we're looking for.
> 
> (Previous versions missed last 0 argument to btrfs_next_extent_item().  Sorry, I
> realize I need to take more time before sending, being more careful on
> everything.)
> 

So do I.

If you want to write something which is unreleated to
changes in a patch. Just put them and changelog belows "---" under
SOB line.
It would be easier for maintainers to apply patches.

And, I noticed patches sent by you are separated in ML. It's OK.
Puting series into one thread is better for review. You can
use tools like 'git-send-email' to send patches.
The last nag: a coverletter is nice with patches.
Link of conversation:
https://www.spinics.net/lists/linux-btrfs/msg77791.html

> Signed-off-by: James Harvey <jamespharvey20@gmail.com>
> ---
>   btrfs-map-logical.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/btrfs-map-logical.c b/btrfs-map-logical.c
> index 2451012b..8a41b037 100644
> --- a/btrfs-map-logical.c
> +++ b/btrfs-map-logical.c
> @@ -83,7 +83,8 @@ again:
>                          ret = btrfs_previous_extent_item(fs_info->extent_root,
>                                                           path, 0);
>                  else
> -                       ret = btrfs_next_item(fs_info->extent_root, path);
> +                       ret = btrfs_next_extent_item(fs_info->extent_root,
> +                                                    path, 0);
After a careful look, if btrfs_next/previous_extent_item is used here.
It's no need to check
====
  if ((search_foward && key.objectid < logical) || 

             (!search_foward && key.objectid > logical) || 

             (key.type != BTRFS_EXTENT_ITEM_KEY && 

              key.type != BTRFS_METADATA_ITEM_KEY)) {
===
Pass @logical as the last parameters of
btrfs_next/previous_extent_item() is simple enough.

Thanks,
Su

>                  if (ret)
>                          goto out;
>                  goto again;
> --
> 2.17.0
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
>