From 8b409dc49c0c3097b9218fc9d5727b8820c863cb Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 13 Dec 2022 13:08:26 -0500 Subject: [PATCH] nfsd: fix handling of readdir in v4root vs. mount upcall timeout commit 4e2c84c5b7d618958c155a025f88e9ccb07a870d upstream. If v4 READDIR operation hits a mountpoint and gets back an error, then it will include that entry in the reply and set RDATTR_ERROR for it to the error. That's fine for "normal" exported filesystems, but on the v4root, we need to be more careful to only expose the existence of dentries that lead to exports. If the mountd upcall times out while checking to see whether a mountpoint on the v4root is exported, then we have no recourse other than to fail the whole operation. Cc: Steve Dickson Link: https://bugzilla.kernel.org/show_bug.cgi?id=216777 Reported-by: JianHong Yin Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Cc: Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4xdr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index bcfeb1a922c0d..78849646fe832 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3570,6 +3570,17 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen, case nfserr_noent: xdr_truncate_encode(xdr, start_offset); goto skip_entry; + case nfserr_jukebox: + /* + * The pseudoroot should only display dentries that lead to + * exports. If we get EJUKEBOX here, then we can't tell whether + * this entry should be included. Just fail the whole READDIR + * with NFS4ERR_DELAY in that case, and hope that the situation + * will resolve itself by the client's next attempt. + */ + if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT) + goto fail; + fallthrough; default: /* * If the client requested the RDATTR_ERROR attribute, -- 2.39.5