Hi Trond, On Fri, 2019-11-08 at 21:22 +0000, Trond Myklebust wrote: > On Fri, 2019-11-08 at 16:02 -0500, schumaker.anna@xxxxxxxxx wrote: > > From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> > > > > Changing a sparse file could have an effect not only on the file > > size, > > but also on the number of blocks used by the file in the underlying > > filesystem. Let's update the SPACE_USED attribute whenever we update > > SIZE to be as accurate as possible. > > > > This patch fixes xfstests generic/568, which tests that fallocating > > an > > unaligned range allocates all blocks touched by that range. Without > > this > > patch, `stat` reports 0 bytes used immediately after the fallocate. > > Adding a `sleep 5` to the test also catches the update, but it's > > better > > to just do it when we know something has changed. > > > > Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> > > --- > > fs/nfs/nfs4proc.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > > index ac9063c06205..00a1f3ec7f22 100644 > > --- a/fs/nfs/nfs4proc.c > > +++ b/fs/nfs/nfs4proc.c > > @@ -3775,7 +3775,7 @@ static int _nfs4_server_capabilities(struct > > nfs_server *server, struct nfs_fh *f > > > > memcpy(server->cache_consistency_bitmask, > > res.attr_bitmask, sizeof(server->cache_consistency_bitmask)); > > server->cache_consistency_bitmask[0] &= > > FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE; > > - server->cache_consistency_bitmask[1] &= > > FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY; > > + server->cache_consistency_bitmask[1] &= > > FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY|FATTR4_WORD1_SPAC > > E_USED; > > I'd rather not do this. Space used is not a cache consistency attribute > , as we do not use it to revalidate the cache and it can be rather > expensive to retrieve on some platforms. Okay, that makes sense. > > I'd therefore prefer that we just make sure we mark the cache validity > with NFS_INO_INVALID_OTHER when we have a write succeed on a sparse > file. It looks like setting falloc_bitmask to use the standard nfs4_fattr_bitmap instead of the cache_consistency_bitmask will also update the SPACE_USED attribute after a fallocate call. I'll play around with NFS_INO_INVALID_OTHER next, but making use of the trailing getattr that ALLOCATE and DEALLOCATE already have seems more straightforward to me. Anna > > > server->cache_consistency_bitmask[2] = 0; > > > > /* Avoid a regression due to buggy server */ > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@xxxxxxxxxxxxxxx > >
