On Sat 30-12-23 15:06:54, yangerkun wrote:
> Commit 3d56b8d2c74c ("ext4: Speed up FITRIM by recording flags in
> ext4_group_info") speed up fstrim by skipping trim trimmed group. We
> also has the chance to clear trimmed once there exists some block free
> for this group(mount without discard), and the next trim for this group
> will work well too.
>
> For mount with discard, we will issue dicard when we free blocks, so
> leave trimmed flag keep alive to skip useless trim trigger from
> userspace seems reasonable. But for some case like ext4 build on
> dm-thinpool(ext4 blocksize 4K, pool blocksize 128K), discard from ext4
> maybe unaligned for dm thinpool, and thinpool will just finish this
> discard(see process_discard_bio when begein equals to end) without
> actually process discard. For this case, trim from userspace can really
> help us to free some thinpool block.
>
> So convert to clear trimmed flag for all case no matter mounted with
> discard or not.
>
> Fixes: 3d56b8d2c74c ("ext4: Speed up FITRIM by recording flags in ext4_group_info")
> Signed-off-by: yangerkun <yangerkun@xxxxxxxxxxxxxxx>
Thanks for the fix. It looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/mballoc.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index d72b5e3c92ec..69240ae775f1 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -3855,11 +3855,8 @@ static void ext4_free_data_in_buddy(struct super_block *sb,
> /*
> * Clear the trimmed flag for the group so that the next
> * ext4_trim_fs can trim it.
> - * If the volume is mounted with -o discard, online discard
> - * is supported and the free blocks will be trimmed online.
> */
> - if (!test_opt(sb, DISCARD))
> - EXT4_MB_GRP_CLEAR_TRIMMED(db);
> + EXT4_MB_GRP_CLEAR_TRIMMED(db);
>
> if (!db->bb_free_root.rb_node) {
> /* No more items in the per group rb tree
> @@ -6481,8 +6478,9 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
> " group:%u block:%d count:%lu failed"
> " with %d", block_group, bit, count,
> err);
> - } else
> - EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
> + }
> +
> + EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
>
> ext4_lock_group(sb, block_group);
> mb_free_blocks(inode, &e4b, bit, count_clusters);
> --
> 2.39.2
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
