On Fri, Nov 20, 2020 at 03:33:51PM -0500, Chuck Lever wrote:
> Code inspection shows that the server's NFSv3 READDIR implementation
> returns the same offset cookie as the client sent, instead of the
> last cookie it returns in the reply's dirlist. This is unlike the
> NFSv2 READDIR, NFSv3 READDIRPLUS, and NFSv4 READDIR implementations,
> and it's been like this since the beginning of kernel git history.
Surely this should have caused actual failures in practice.
> I copied the logic from nfsd3_proc_readdirplus().
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> fs/nfsd/nfs3proc.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
> index d9be589fed15..e0ad18d6b5a8 100644
> --- a/fs/nfsd/nfs3proc.c
> +++ b/fs/nfsd/nfs3proc.c
> @@ -430,6 +430,7 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
> struct nfsd3_readdirargs *argp = rqstp->rq_argp;
> struct nfsd3_readdirres *resp = rqstp->rq_resp;
> int count = 0;
> + loff_t offset;
> struct page **p;
> caddr_t page_addr = NULL;
>
> @@ -448,7 +449,9 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
> resp->common.err = nfs_ok;
> resp->buffer = argp->buffer;
> resp->rqstp = rqstp;
> - resp->status = nfsd_readdir(rqstp, &resp->fh, (loff_t *)&argp->cookie,
Doesn't nfsd_readdir() update argp->cookie to point to the last offset?
> + offset = argp->cookie;
> +
> + resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
> &resp->common, nfs3svc_encode_entry);
> memcpy(resp->verf, argp->verf, 8);
> count = 0;
> @@ -464,8 +467,6 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
> }
> resp->count = count >> 2;
> if (resp->offset) {
> - loff_t offset = argp->cookie;
So, this shouldn't be equal to the initial cookie any more.
Am I missing something?
--b.
> -
> if (unlikely(resp->offset1)) {
> /* we ended up with offset on a page boundary */
> *resp->offset = htonl(offset >> 32);
>
