diff mbox series

btrfs: update documentation for a block group's bg_list member

Message ID 148d635697bfb4ac3f9010526a6d79b8ee34316d.1686061295.git.fdmanana@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs: update documentation for a block group's bg_list member | expand

Commit Message

Filipe Manana June 6, 2023, 2:26 p.m. UTC 
From: Filipe Manana <fdmanana@suse.com>

Currently we are only documentating two uses of the bg_list member of a
block group, but there two more:

1) To track deleted block groups for discard purposes, introduced in
   commit e33e17ee1098 ("btrfs: add missing discards when unpinning
   extents with -o discard");

2) To track block groups for automatic reclaim, introduced more recently
   by commit 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")

So document those two other use cases.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/block-group.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

Comments

Johannes Thumshirn June 6, 2023, 3:53 p.m. UTC | #1 
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
David Sterba June 6, 2023, 4:26 p.m. UTC | #2 
On Tue, Jun 06, 2023 at 03:26:03PM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> Currently we are only documentating two uses of the bg_list member of a
> block group, but there two more:
> 
> 1) To track deleted block groups for discard purposes, introduced in
>    commit e33e17ee1098 ("btrfs: add missing discards when unpinning
>    extents with -o discard");
> 
> 2) To track block groups for automatic reclaim, introduced more recently
>    by commit 18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
> 
> So document those two other use cases.
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Added to misc-next, thanks.
diff mbox series

Patch

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index cc0e4b37db2d..f204addc3fe8 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -162,7 +162,14 @@  struct btrfs_block_group {
 	 */
 	struct list_head cluster_list;
 
-	/* For delayed block group creation or deletion of empty block groups */
+	/*
+	 * Used for several lists:
+	 *
+	 * 1) struct btrfs_fs_info::unused_bgs
+	 * 2) struct btrfs_fs_info::reclaim_bgs
+	 * 3) struct btrfs_transaction::deleted_bgs
+	 * 4) struct btrfs_trans_handle::new_bgs
+	 */
 	struct list_head bg_list;
 
 	/* For read-only block groups */