[PATCH v2] btrfs: Remove btrfs_bio::flags member

[PATCH v2] btrfs: Remove btrfs_bio::flags member

[Qu Wenruo]

This member is not used by any one, just remove it.

And since it's between two pointers, such removal should save us a
pointer size of the structure.

The last user of btrfs_bio::flags is removed in commit 326e1dbb5736
("block: remove management of bi_remaining when restoring original
bi_end_io").

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
Changelog:
v2:
- Mention the when last user of btrfs_bio::flags is removed.
- Don't mention btrfs_bio::map_type in commit message.
  Since btrfs_bio::flags is for another purpose, it has nothing to do
  with btrfs_bio::map_type.
---
 fs/btrfs/volumes.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index a7da1f3e3627..5acf5c507ec2 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -330,7 +330,6 @@ struct btrfs_bio {
 	u64 map_type; /* get from map_lookup->type */
 	bio_end_io_t *end_io;
 	struct bio *orig_bio;
-	unsigned long flags;
 	void *private;
 	atomic_t error;
 	int max_errors;
-- 
2.23.0

Re: [PATCH v2] btrfs: Remove btrfs_bio::flags member

[David Sterba]

On Thu, Oct 24, 2019 at 09:38:29AM +0800, Qu Wenruo wrote:
> This member is not used by any one, just remove it.
> 
> And since it's between two pointers, such removal should save us a
> pointer size of the structure.
> 
> The last user of btrfs_bio::flags is removed in commit 326e1dbb5736
> ("block: remove management of bi_remaining when restoring original
> bi_end_io").

Oh, that's an old patch, 2015. I'll add a stable tag though it's not a
fix but the size reduction of a frequently used structure is a good
thing. Thanks.