On Wed, 2023-08-30 at 15:42 -0400, Benjamin Coddington wrote:
> Again we have claimed regressions for walking a directory tree, this time
> with the "find" utility which always tries to optimize away asking for any
> attributes until it has a complete list of entries. This behavior makes
> the readdir plus heuristic do the wrong thing, which causes a storm of
> GETATTRs to determine each entry's type in order to continue the walk.
>
> For v4 add the type attribute to each READDIR request to include it no
> matter the heuristic. This allows a simple `find` command to proceed
> quickly through a directory tree.
>
The important bit here is that with v4, we can fill out d_type even when
"plus" is false, at little cost. The downside is that non-plus READDIR
replies will now be a bit larger on the wire. I think it's a worthwhile
tradeoff though.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
> Suggested-by: Jeff Layton <jlayton@xxxxxxxxxx>
> Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
>
> --
> On v2: Don't add the type attribute twice
> ---
> fs/nfs/nfs4xdr.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index deec76cf5afe..7200d6f7cd7b 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -1602,7 +1602,7 @@ static void encode_read(struct xdr_stream *xdr, const struct nfs_pgio_args *args
> static void encode_readdir(struct xdr_stream *xdr, const struct nfs4_readdir_arg *readdir, struct rpc_rqst *req, struct compound_hdr *hdr)
> {
> uint32_t attrs[3] = {
> - FATTR4_WORD0_RDATTR_ERROR,
> + FATTR4_WORD0_TYPE|FATTR4_WORD0_RDATTR_ERROR,
> FATTR4_WORD1_MOUNTED_ON_FILEID,
> };
> uint32_t dircount = readdir->count;
> @@ -1612,7 +1612,7 @@ static void encode_readdir(struct xdr_stream *xdr, const struct nfs4_readdir_arg
> unsigned int i;
>
> if (readdir->plus) {
> - attrs[0] |= FATTR4_WORD0_TYPE|FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE|
> + attrs[0] |= FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE|
> FATTR4_WORD0_FSID|FATTR4_WORD0_FILEHANDLE|FATTR4_WORD0_FILEID;
> attrs[1] |= FATTR4_WORD1_MODE|FATTR4_WORD1_NUMLINKS|FATTR4_WORD1_OWNER|
> FATTR4_WORD1_OWNER_GROUP|FATTR4_WORD1_RAWDEV|
