* [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK
@ 2018-04-27 8:22 Gu Jinxiang
2018-04-27 8:28 ` Nikolay Borisov
2018-05-01 13:44 ` David Sterba
0 siblings, 2 replies; 3+ messages in thread
From: Gu Jinxiang @ 2018-04-27 8:22 UTC (permalink / raw)
To: linux-btrfs
In btrfs_shrink_device, before btrfs_search_slot, path->reada is
set to READA_FORWARD. But I think READA_BACK is correct.
Since,
1.key.offset is set to (u64)-1
2.After btrfs_search_slot, btrfs_previous_item is called.
So, for readahead previous items, READA_BACK is correct one.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.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 292266f6ab9c..1a3506a3003d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4473,7 +4473,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
if (!path)
return -ENOMEM;
- path->reada = READA_FORWARD;
+ path->reada = READA_BACK;
mutex_lock(&fs_info->chunk_mutex);
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK
2018-04-27 8:22 [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK Gu Jinxiang
@ 2018-04-27 8:28 ` Nikolay Borisov
2018-05-01 13:44 ` David Sterba
1 sibling, 0 replies; 3+ messages in thread
From: Nikolay Borisov @ 2018-04-27 8:28 UTC (permalink / raw)
To: Gu Jinxiang, linux-btrfs
On 27.04.2018 11:22, Gu Jinxiang wrote:
> In btrfs_shrink_device, before btrfs_search_slot, path->reada is
> set to READA_FORWARD. But I think READA_BACK is correct.
> Since,
> 1.key.offset is set to (u64)-1
> 2.After btrfs_search_slot, btrfs_previous_item is called.
> So, for readahead previous items, READA_BACK is correct one.
My analysis arrives at the same conclusions so:
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
>
> Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.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 292266f6ab9c..1a3506a3003d 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -4473,7 +4473,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
> if (!path)
> return -ENOMEM;
>
> - path->reada = READA_FORWARD;
> + path->reada = READA_BACK;
>
> mutex_lock(&fs_info->chunk_mutex);
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK
2018-04-27 8:22 [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK Gu Jinxiang
2018-04-27 8:28 ` Nikolay Borisov
@ 2018-05-01 13:44 ` David Sterba
1 sibling, 0 replies; 3+ messages in thread
From: David Sterba @ 2018-05-01 13:44 UTC (permalink / raw)
To: Gu Jinxiang; +Cc: linux-btrfs
On Fri, Apr 27, 2018 at 04:22:07PM +0800, Gu Jinxiang wrote:
> In btrfs_shrink_device, before btrfs_search_slot, path->reada is
> set to READA_FORWARD. But I think READA_BACK is correct.
> Since,
> 1.key.offset is set to (u64)-1
> 2.After btrfs_search_slot, btrfs_previous_item is called.
> So, for readahead previous items, READA_BACK is correct one.
>
> Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Added to next, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-05-01 13:46 UTC | newest]
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2018-04-27 8:22 [PATCH] btrfs: modify path->reada in btrfs_shrink_device to READA_BACK Gu Jinxiang
2018-04-27 8:28 ` Nikolay Borisov
2018-05-01 13:44 ` David Sterba
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