From e7b184f199fd3c80b618ec8244cbda70857d2779 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 2 Mar 2010 11:18:40 -0500 Subject: [PATCH] nfsd4: document lease/grace-period limits The current documentation here is out of date, and not quite right. (Future work: some user documentation would be useful.) Signed-off-by: J. Bruce Fields --- fs/nfsd/nfsctl.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 7ab70ff..413cb8e 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1208,9 +1208,6 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size) #ifdef CONFIG_NFSD_V4 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size, time_t *time) { - /* if size > 10 seconds, call - * nfs4_reset_lease() then write out the new lease (seconds) as reply - */ char *mesg = buf; int rv, i; @@ -1220,6 +1217,18 @@ static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size, tim rv = get_int(&mesg, &i); if (rv) return rv; + /* + * Some sanity checking. We don't have a reason for + * these particular numbers, but problems with the + * extremes are: + * - Too short: the briefest network outage may + * cause clients to lose all their locks. Also, + * the frequent polling may be wasteful. + * - Too long: do you really want reboot recovery + * to take more than an hour? Or to make other + * clients wait an hour before being able to + * revoke a dead client's locks? + */ if (i < 10 || i > 3600) return -EINVAL; *time = i; -- 1.8.2.3