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@poczta.fm Fixes: 6df25e58532b ("nfs: remove reliance on bdi congestion") Signed-off-by: NeilBrown neilb@suse.de --- fs/nfs/write.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index b664caea8b4e..9e345d3c305a 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -668,8 +668,10 @@ static int nfs_writepage_locked(struct folio *folio, 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,