[PATCH] btrfs: relax bg_reclaim_threshold for debug purpose

[PATCH] btrfs: relax bg_reclaim_threshold for debug purpose

[Naohiro Aota]

Currently, /sys/fs/btrfs/<UUID>/bg_reclaim_threshold is limited to 0
(disable) or [50 .. 100]%, so we need to fill 50% of a device to start the
auto reclaim process. It is cumbersome to do so when we want to shake out
possible race issues of normal write vs reclaim.

Relax the threshold check under the BTRFS_DEBUG option.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/sysfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 37fc58a7f27e..25294e624851 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1262,8 +1262,13 @@ static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_BTRFS_DEBUG
+	if (thresh != 0 && (thresh > 100))
+		return -EINVAL;
+#else
 	if (thresh != 0 && (thresh <= 50 || thresh > 100))
 		return -EINVAL;
+#endif
 
 	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
 
-- 
2.39.2

Re: [PATCH] btrfs: relax bg_reclaim_threshold for debug purpose

[Johannes Thumshirn]

On 13.03.23 08:47, Naohiro Aota wrote:
> Currently, /sys/fs/btrfs/<UUID>/bg_reclaim_threshold is limited to 0
> (disable) or [50 .. 100]%, so we need to fill 50% of a device to start the
> auto reclaim process. It is cumbersome to do so when we want to shake out
> possible race issues of normal write vs reclaim.
> 
> Relax the threshold check under the BTRFS_DEBUG option.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Fine by me,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: [PATCH] btrfs: relax bg_reclaim_threshold for debug purpose

[David Sterba]

On Mon, Mar 13, 2023 at 04:46:54PM +0900, Naohiro Aota wrote:
> Currently, /sys/fs/btrfs/<UUID>/bg_reclaim_threshold is limited to 0
> (disable) or [50 .. 100]%, so we need to fill 50% of a device to start the
> auto reclaim process. It is cumbersome to do so when we want to shake out
> possible race issues of normal write vs reclaim.
> 
> Relax the threshold check under the BTRFS_DEBUG option.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Added to misc-next, thanks.