From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> The following patch set attempts to add support for the RWF_DONTCACHE flag in preadv2() and pwritev2() on NFS filesystems. The main issue is allowing support on 2 stage writes (i.e. unstable WRITE followed by a COMMIT) since those don't follow the current assumption that the 'dropbehind' flag can be fulfilled as soon as the writeback lock is dropped. v2: - Make use of the new iocb parameter for nfs_write_begin() v3: - Set/clear PG_DROPBEHIND on the head of the nfs_page group - Simplify helper folio_end_dropbehind Trond Myklebust (2): filemap: Add a helper for filesystems implementing dropbehind NFS: Enable the RWF_DONTCACHE flag for the NFS client fs/nfs/file.c | 6 ++---- fs/nfs/nfs4file.c | 1 + fs/nfs/write.c | 20 +++++++++++++++++--- include/linux/nfs_page.h | 1 + include/linux/pagemap.h | 1 + mm/filemap.c | 11 +++++++++++ 6 files changed, 33 insertions(+), 7 deletions(-) -- 2.50.1
