Re: [PATCH v3 1/1] fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()

[Andrew Morton <akpm@linux-foundation.org>]

On Mon,  5 Jan 2026 13:17:27 -0800 Joanne Koong <joannelkoong@gmail.com> wrote:

> Above the while() loop in wait_sb_inodes(), we document that we must
> wait for all pages under writeback for data integrity. Consequently, if
> a mapping, like fuse, traditionally does not have data integrity
> semantics, there is no need to wait at all; we can simply skip these
> inodes.
> 
> This restores fuse back to prior behavior where syncs are no-ops. This
> fixes a user regression where if a system is running a faulty fuse
> server that does not reply to issued write requests, this causes
> wait_sb_inodes() to wait forever.
> 
> Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree")
> Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
> Reported-by: J. Neuschäfer <j.neuschaefer@gmx.net>
> Cc: stable@vger.kernel.org
> Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
> Reviewed-by: Bernd Schubert <bschubert@ddn.com>
> Tested-by: J. Neuschäfer <j.neuschaefer@gmx.net>

Thanks.

>  fs/fs-writeback.c       |  7 ++++++-
>  fs/fuse/file.c          |  4 +++-
>  include/linux/pagemap.h | 11 +++++++++++
>  3 files changed, 20 insertions(+), 2 deletions(-)

I'll queue this in mm.git's mm-hotfixes branches for a 6.19-rcX merge.