The patch titled
Subject: fat: avoid oops when bdi->io_pages==0
has been added to the -mm tree. Its filename is
fat-avoid-oops-when-bdi-io_pages==0.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/fat-avoid-oops-when-bdi-io_pages%3D%3D0.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/fat-avoid-oops-when-bdi-io_pages%3D%3D0.patch
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------------------------------------------------------
From: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
Subject: fat: avoid oops when bdi->io_pages==0
On one system, there was bdi->io_pages==0. This seems to be the bug of a
driver somewhere, which perhaps failed to initialize io_pages. We should
fix it though - it is better to avoid the divide-by-zero Oops.
So add a check for this.
Link: http://lkml.kernel.org/r/87ft85osn6.fsf@xxxxxxxxxxxxxxxxxx
Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [5.8+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/fat/fatent.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/fat/fatent.c~fat-avoid-oops-when-bdi-io_pages==0
+++ a/fs/fat/fatent.c
@@ -660,7 +660,7 @@ static void fat_ra_init(struct super_blo
if (fatent->entry >= ent_limit)
return;
- if (ra_pages > sb->s_bdi->io_pages)
+ if (sb->s_bdi->io_pages && ra_pages > sb->s_bdi->io_pages)
ra_pages = rounddown(ra_pages, sb->s_bdi->io_pages);
reada_blocks = ra_pages << (PAGE_SHIFT - sb->s_blocksize_bits + 1);
_
Patches currently in -mm which might be from hirofumi@xxxxxxxxxxxxxxxxxx are
fat-avoid-oops-when-bdi-io_pages==0.patch
