+ nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on.patch added to mm-nonmm-unstable branch

+ nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Subject: nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
Date: Thu, 9 May 2024 07:14:29 +0900

The BUG_ON check performed on the return value of __getblk() in
nilfs_finish_roll_forward() assumes that a buffer that has been
successfully read once is retrieved with the same parameters and does not
fail (__getblk() does not return an error due to memory allocation
failure).  Also, nilfs_finish_roll_forward() is called at most once during
mount.

Taking these into consideration, rewrite the check to use WARN_ON() to
avoid using BUG_ON().

Link: https://lkml.kernel.org/r/20240508221429.7559-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/nilfs2/recovery.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/nilfs2/recovery.c~nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on
+++ a/fs/nilfs2/recovery.c
@@ -699,7 +699,9 @@ static void nilfs_finish_roll_forward(st
 		return;
 
 	bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize);
-	BUG_ON(!bh);
+	if (WARN_ON(!bh))
+		return;  /* should never happen */
+
 	memset(bh->b_data, 0, bh->b_size);
 	set_buffer_dirty(bh);
 	err = sync_dirty_buffer(bh);
_

Patches currently in -mm which might be from konishi.ryusuke@gmail.com are

nilfs2-convert-bug_on-in-nilfs_finish_roll_forward-to-warn_on.patch