[PATCH] btrfs-progs: fsck: Add more explanation on low memory mode

[PATCH] btrfs-progs: fsck: Add more explanation on low memory mode

[Qu Wenruo]

It seems the initial support for low memory mode will come in recent
release, it's better to add more explanation on the unsupported
functions, to avoid user reporting known bugs.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 Documentation/btrfs-check.asciidoc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/btrfs-check.asciidoc b/Documentation/btrfs-check.asciidoc
index 4e27863..6b09662 100644
--- a/Documentation/btrfs-check.asciidoc
+++ b/Documentation/btrfs-check.asciidoc
@@ -97,7 +97,14 @@ NOTE: Do not use unless you know what you're doing.
 check fs in low memory usage mode(experimental)
 May takes longer time than normal check.
 +
-NOTE: Doesn't work with '--repair' option yet.
+[NOTE]
+==========================
+As this feature is still under development, some functions are not implemented
+yet
+
+- No support for '--repair' yet.
+- Only reduce memory usage of extent tree check. No effect for fs tree yet.
+==========================
 
 EXIT STATUS
 -----------
-- 
2.8.2

Re: [PATCH] btrfs-progs: fsck: Add more explanation on low memory mode

[David Sterba]

On Fri, May 20, 2016 at 10:21:07AM +0800, Qu Wenruo wrote:
> It seems the initial support for low memory mode will come in recent
> release, it's better to add more explanation on the unsupported
> functions, to avoid user reporting known bugs.
> 
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>  Documentation/btrfs-check.asciidoc | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/btrfs-check.asciidoc b/Documentation/btrfs-check.asciidoc
> index 4e27863..6b09662 100644
> --- a/Documentation/btrfs-check.asciidoc
> +++ b/Documentation/btrfs-check.asciidoc
> @@ -97,7 +97,14 @@ NOTE: Do not use unless you know what you're doing.
>  check fs in low memory usage mode(experimental)
>  May takes longer time than normal check.
>  +
> -NOTE: Doesn't work with '--repair' option yet.
> +[NOTE]
> +==========================
> +As this feature is still under development, some functions are not implemented
> +yet
> +
> +- No support for '--repair' yet.
> +- Only reduce memory usage of extent tree check. No effect for fs tree yet.
> +==========================

The help text is too short to be useful, I'd like to see something more
comprehensive so the user knows what the low-mem mode does compared to
the current state.