FAILED: patch "[PATCH] xfs: fix short ifork reaping computation in" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x eacb8479507756c3305994e87fb2fb1183827e98
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026091658-cornball-gerbil-7e76@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From eacb8479507756c3305994e87fb2fb1183827e98 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <[email protected]>
Date: Tue, 1 Sep 2026 22:42:15 -0700
Subject: [PATCH] xfs: fix short ifork reaping computation in
xreap_bmapi_binval

LOLLM got really confused about the update to imap->br_blockcount in xreap_bmapi_binval if xreap_inc_binval returns false. The intent of this code is that we shorten the imap to whatever length of space we invalidated so that the next iteration through the loop will start wherever we left off. Unfortunately, the calculation sets br_blockcount to the amount of *unfinished* work, which means that we pointlessly re-scan blocks that we already reaped. This is benign, but we should fix the computation anyway.

index 496c6eab555e..f698b9be3dd1 100644
@@ -1399,7 +1399,7 @@ xreap_bmapi_binval(
 			 * far we've gotten.
 			 */
 			if (!xreap_inc_binval(rs)) {
-				imap->br_blockcount = agbno_next - bno;
+				imap->br_blockcount = bno - agbno;
 				goto out;
 			}
 		}

From: "Darrick J. Wong" <[email protected]>

[ Upstream commit eacb8479507756c3305994e87fb2fb1183827e98 ]

LOLLM got really confused about the update to imap->br_blockcount in xreap_bmapi_binval if xreap_inc_binval returns false. The intent of this code is that we shorten the imap to whatever length of space we invalidated so that the next iteration through the loop will start wherever we left off. Unfortunately, the calculation sets br_blockcount to the amount of *unfinished* work, which means that we pointlessly re-scan blocks that we already reaped. This is benign, but we should fix the computation anyway.

---
 fs/xfs/scrub/reap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 8688edec58755..adce759f1bff3 100644
@@ -861,7 +861,7 @@ xreap_bmapi_binval(
 			 * much of the mapping we've seen so far.
 			 */
 			if (invalidated > XREAP_MAX_BINVAL) {
-				imap->br_blockcount = agbno_next - bno;
+				imap->br_blockcount = bno - agbno;
 				goto out;
 			}
 		}

2.53.0