This is a note to let you know that I've just added the patch titled
NFS: Fix data corruption caused by congestion.
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfs-fix-data-corruption-caused-by-congestion.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From neilb@xxxxxxx Mon Mar 4 12:29:59 2024
From: "NeilBrown" <neilb@xxxxxxx>
Date: Wed, 28 Feb 2024 10:23:31 +1100
Subject: NFS: Fix data corruption caused by congestion.
To: stable@xxxxxxxxxxxxxxx, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>, Anna Schumaker <anna@xxxxxxxxxx>
Cc: linux-nfs@xxxxxxxxxxxxxxx
Message-ID: <170907621128.24797.4390391329078744015@xxxxxxxxxxxxxxxxxxxxx>
when AOP_WRITEPAGE_ACTIVATE is returned (as NFS does when it detects
congestion) it is important that the folio is redirtied.
nfs_writepage_locked() doesn't do this, so files can become corrupted as
writes can be lost.
Note that this is not needed in v6.8 as AOP_WRITEPAGE_ACTIVATE cannot be
returned. It is needed for kernels v5.18..v6.7. Prior to 6.3 the patch
is different as it needs to mention "page", not "folio".
Reported-and-tested-by: Jacek Tomaka <Jacek.Tomaka@xxxxxxxxx>
Fixes: 6df25e58532b ("nfs: remove reliance on bdi congestion")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/write.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -668,8 +668,10 @@ static int nfs_writepage_locked(struct f
int err;
if (wbc->sync_mode == WB_SYNC_NONE &&
- NFS_SERVER(inode)->write_congested)
+ NFS_SERVER(inode)->write_congested) {
+ folio_redirty_for_writepage(wbc, folio);
return AOP_WRITEPAGE_ACTIVATE;
+ }
nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
nfs_pageio_init_write(&pgio, inode, 0, false,
Patches currently in stable-queue which might be from neilb@xxxxxxx are
queue-6.6/nfs-fix-data-corruption-caused-by-congestion.patch
