From b880092109323d1cc608c420fa712d3e19508e13 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 30 Jan 2017 17:17:00 +1100 Subject: [PATCH] NFSDv4: use export cache flushtime for changeid on V4ROOT objects. If you change the set of filesystems that are exported, then the contents of various directories in the NFSv4 pseudo-root is likely to change. However the change-id of those directories is currently tied to the underlying directory, so the client may not see the changes in a timely fashion. This patch changes the change-id number to be derived from the "flush_time" of the export cache. Whenever any changes are made to the set of exported filesystems, this flush_time is updated. The result is that clients see changes to the set of exported filesystems much more quickly, often immediately. Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4xdr.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 3cc190755958..7e4df80456ff 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1966,9 +1966,13 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) DECODE_TAIL; } -static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode) +static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode, + struct svc_export *exp) { - if (IS_I_VERSION(inode)) { + if (exp->ex_flags & NFSEXP_V4ROOT) { + *p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time)); + *p++ = 0; + } else if (IS_I_VERSION(inode)) { p = xdr_encode_hyper(p, inode->i_version); } else { *p++ = cpu_to_be32(stat->ctime.tv_sec); @@ -2493,7 +2497,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, p = xdr_reserve_space(xdr, 8); if (!p) goto out_resource; - p = encode_change(p, &stat, d_inode(dentry)); + p = encode_change(p, &stat, d_inode(dentry), exp); } if (bmval0 & FATTR4_WORD0_SIZE) { p = xdr_reserve_space(xdr, 8);