From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Thu, 23 Jan 2025 18:06:35 +0000 (-0500)
Subject: bcachefs: Don't touch journal_buf->data->seq in journal_res_get
X-Git-Tag: v6.15-rc1~146^2~134
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2e853fdbc74411643b00a14ee75ca234675a9bf2;p=thirdparty%2Fkernel%2Flinux.git

bcachefs: Don't touch journal_buf->data->seq in journal_res_get

This is a small optimization, reducing the number of cachelines we touch
in the fast path - and it's also necessary for the next patch that
increases JOURNAL_BUF_NR.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/journal.h b/fs/bcachefs/journal.h
index 1e5fcfe3624af..e514d664b8aee 100644
--- a/fs/bcachefs/journal.h
+++ b/fs/bcachefs/journal.h
@@ -364,7 +364,10 @@ static inline int journal_res_get_fast(struct journal *j,
 
 	res->ref	= true;
 	res->offset	= old.cur_entry_offset;
-	res->seq	= le64_to_cpu(j->buf[old.idx].data->seq);
+	res->seq	= journal_cur_seq(j);
+	res->seq -= (res->seq - old.idx) & JOURNAL_BUF_MASK;
+
+	EBUG_ON(res->seq != le64_to_cpu(j->buf[old.idx].data->seq));
 	return 1;
 }