X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fexportfs%2Fexports.man;h=62239441f6f8485e027b7ea33abd1401e40e56db;hp=767db40216938477e749a7c4bd59d8a05808b970;hb=d38ea02d0e4bcdc4e0114567028596f7bcba45b9;hpb=cd79f524f08acd2481752b3114c7c7b2359d0fac

diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man
index 767db40..6223944 100644
--- a/utils/exportfs/exports.man
+++ b/utils/exportfs/exports.man
@@ -17,12 +17,18 @@ and to the kernel based NFS file server daemon
 .PP
 The file format is similar to the SunOS
 .I exports
-file, except that several additional options are permitted.  Each line
-contains an export point and a list of machine or netgroup names allowed
-to mount the file system at that point.  An optional parenthesized list
-of export parameters may follow each machine name.  Blank lines are
-ignored, and a # introduces a comment to the end of the line. Entries may
-be continued across newlines using a backslash.
+file. Each line contains an export point and a whitespace-separated list
+of clients allowed to mount the file system at that point. Each listed
+client may be immediately followed by a parenthesized, comma-separated
+list of export options for that client. No whitespace is permitted
+between a client and its option list.
+.PP
+Blank lines are ignored.  A pound sign ("#") introduces a comment to the
+end of the line. Entries may be continued across newlines using a
+backslash. If an export name contains spaces it should be quoted using
+double quotes. You can also specify spaces or other unusual character in
+the export name using a backslash followed by the character code as three
+octal digits.
 .PP
 .SS Machine Name Formats
 NFS clients may be specified in a number of ways:
@@ -39,15 +45,21 @@ parts or those containing a single dash (\-) are ignored.
 .IP "wildcards
 Machine names may contain the wildcard characters \fI*\fR and \fI?\fR.
 This can be used to make the \fIexports\fR file more compact; for instance,
-\fI*.cs.foo.edu\fR matches all hosts in the domain \fIcs.foo.edu\fR. However,
-these wildcard characters do not match the dots in a domain name, so the
-above pattern does not include hosts such as \fIa.b.cs.foo.edu\fR.
+\fI*.cs.foo.edu\fR matches all hosts in the domain
+\fIcs.foo.edu\fR.  As these characters also match the dots in a domain
+name, the given pattern will also match all hosts within any subdomain
+of \fIcs.foo.edu\fR.
 .IP "IP networks
 You can also export directories to all hosts on an IP (sub-) network
 simultaneously. This is done by specifying an IP address and netmask pair
 as
-.IR address/netmask .
-.TP
+.IR address/netmask
+where the netmask can be specified in dotted-decimal format, or as a
+contiguous mask length (for example, either `/255.255.252.0' or `/22' appended
+to the network base address result in identical subnetworks with 10 bits of
+host). Wildcard characters generally do not work on IP addresses, though they
+may work by accident when reverse DNS lookups fail.
+'''.TP
 '''.B =public
 '''This is a special ``hostname'' that identifies the given directory name
 '''as the public root directory (see the section on WebNFS in
@@ -84,17 +96,31 @@ This can also be made explicit by using
 the
 .IR ro " option.
 .TP
-.IR sync
-This option requests that all file writes be committed to disc before
-the write request completes.  This is required for complete safety of
-data in the face of a server crash, but incurs a performance hit.
-The default is to allow the server to write the data out whenever it
-is ready.  This can be explicitly requested with the
-.IR async " option.
+.IR async
+This option allows the NFS server to violate the NFS protocol and
+reply to requests before any changes made by that request have been
+committed to stable storage (e.g. disc drive).
+
+Using this option usually improves performance, but at the cost that
+an unclean server restart (i.e. a crash) can cause data to be lost or
+corrupted.
+
+In releases of nfs-utils upto and including 1.0.0, this option was the
+default.  In this and future releases,
+.I sync
+is the default, and
+.I async
+must be explicit requested if needed.
+To help make system adminstrators aware of this change, 'exportfs'
+will issue a warning if neither
+.I sync
+nor
+.I async
+is specified.
 .TP
 .IR no_wdelay
-This option only has effect if
-.I sync
+This option has no effect if
+.I async
 is also set.  The NFS server will normally delay committing a write request
 to disc slightly if it suspects that another related write request may be in
 progress or may arrive soon.  This allows multiple write requests to
@@ -211,6 +237,25 @@ 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.
+
 .SS User ID Mapping
 .PP
 .I nfsd