linux-erofs.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx
@ 2021-09-14  3:59 Yue Hu
  2021-09-14  4:37 ` Gao Xiang
  0 siblings, 1 reply; 7+ messages in thread
From: Yue Hu @ 2021-09-14  3:59 UTC (permalink / raw)
  To: xiang, chao; +Cc: huyue2, linux-erofs, linux-kernel, zhangwen, zbestahu

From: Yue Hu <huyue2@yulong.com>

Currently, the whole indexes will only be compacted 4B if
compacted_4b_initial > totalidx. So, the calculated compacted_2b
is worthless for that case. It may waste CPU resources.

No need to update compacted_4b_initial as mkfs since it's used to
fulfill the alignment of the 1st compacted_2b pack and would handle
the case above.

We also need to clarify compacted_4b_end here. It's used for the
last lclusters which aren't fitted in the previous compacted_2b
packs.

Some messages are from Xiang.

Signed-off-by: Yue Hu <huyue2@yulong.com>
---
 fs/erofs/zmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 9fb98d8..aeed404 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 	if (compacted_4b_initial == 32 / 4)
 		compacted_4b_initial = 0;
 
-	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
+	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
+	    compacted_4b_initial <= totalidx) {
 		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
 	else
 		compacted_2b = 0;
-- 
1.9.1


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-09-23 15:13 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-14  3:59 [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx Yue Hu
2021-09-14  4:37 ` Gao Xiang
2021-09-14  4:57   ` Yue Hu
2021-09-14  5:11     ` Gao Xiang
2021-09-23 11:49     ` Gao Xiang
2021-09-23 12:50       ` Yue Hu
2021-09-23 15:13       ` Chao Yu

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).