Prepare to support gss authentication and idmap looks for nfsv4

[nfs-utils.git] / utils / exportfs / exports.man

diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man
index 7ab7640da1350b8f8b6733c007135fb13d639abe..7a032bc9609453e3295e84b891c742dc2cfe84a5 100644 (file)
--- a/utils/exportfs/exports.man
+++ b/utils/exportfs/exports.man
@@ -79,6 +79,11 @@ may work by accident when reverse DNS lookups fail.
 '''.B \-\-public\-root
 '''option. Multiple specifications of a public root will be ignored.
 .PP
+.SS RPCSEC_GSS security
+To restrict access to an export using rpcsec_gss security, use the special
+string "gss/krb5" as the client.  It is not possible to simultaneously require
+rpcsec_gss and to make requirements on the IP address of the client.
+.PP
 .SS General Options
 .IR exportfs
 understands the following export options:
@@ -237,6 +242,47 @@ or
 '''.TP
 '''.IR link_absolute
 '''Leave all symbolic link as they are. This is the default operation.
+
+.TP
+.IR mountpoint= path
+.TP
+.I mp
+This option makes it possible to only export a directory if it has
+successfully been mounted.
+If no path is given (e.g.
+.IR mountpoint " or " mp )
+then the export point must also be a mount point.  If it isn't then
+the export point is not exported.  This allows you to be sure that the
+directory underneath a mountpoint will never be exported by accident
+if, for example, the filesystem failed to mount due to a disc error.
+
+If a path is given (e.g.
+.IR mountpoint= "/path or " mp= /path)
+then the nominted path must be a mountpoint for the exportpoint to be
+exported.
+
+.TP
+.IR fsid= num
+This option forces the filesystem identification portion of the file
+handle and file attributes used on the wire to be
+.I num
+instead of a number derived from the major and minor number of the
+block device on which the filesystem is mounted.  Any 32 bit number
+can be used, but it must be unique amongst all the exported filesystems.
+
+This can be useful for NFS failover, to ensure that both servers of
+the failover pair use the same NFS file handles for the shared filesystem
+thus avoiding stale file handles after failover.
+
+Some Linux filesystems are not mounted on a block device; exporting
+these via NFS requires the use of the
+.I fsid
+option (although that may still not be enough).
+
+The value  0 has a special meaning when use with NFSv4.  NFSv4 has a
+concept of a root of the overall exported filesystem. The export point
+exported with fsid=0 will be used as this root.
+
 .SS User ID Mapping
 .PP
 .I nfsd