See Changelog

diff --git a/ChangeLog b/ChangeLog
index 59276ddc2eadd396190625d29536ad3c8f564758..93d5ab8ca9824b9f10665b414cc2c78f06d62ce6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2002-01-17   Adrian Drzewiecki <drze@MissionCriticalLinux.com>
+            NeilBrown <neilb@cse.unsw.edu.au>
+
+       * support/nfs/exports.c: remove NFSEXP_ASYNC as a default
+       flag so that "sync" becomes the default.
+       Check that either "sync" or "async" is given as an option
+       and warn if neither are present
+       * utils/exportfs/exports.man: change documentation for "sync"
+       to be documentation for "async".
+       * utils/exportfs/exportfs.man: note that "sync" is the default
+       rather than "async"
+       
+       
 2002-01-02  Chip Salzenberg  <chip@pobox.com>
 
        * support/export/nfsctl.c (expsetup): Don't export entries that

diff --git a/support/nfs/exports.c b/support/nfs/exports.c
index 7e0decf0b4d12cb77b868aff7eb4f7b7a48f2f15..0dce25ff9291dd28d0c4b608c50fe1cc289f9d62 100644 (file)
--- a/support/nfs/exports.c
+++ b/support/nfs/exports.c
@@ -29,7 +29,7 @@
 #include "xio.h"
 
 #define EXPORT_DEFAULT_FLAGS   \
-  (NFSEXP_ASYNC|NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES)
+  (NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES)
 
 static char    *efname = NULL;
 static XFILE   *efp = NULL;
@@ -117,10 +117,8 @@ getexportent(int fromkernel)
                        return NULL;
                }
                *sp = '\0';
-               if (parseopts(opt, &ee) < 0)
-                       return NULL;
        } else {
-           xlog(L_WARNING, "No options for %s %s: suggest %s() to avoid warning", ee.e_path, exp, exp);
+           xlog(L_WARNING, "No options for %s %s: suggest %s(sync) to avoid warning", ee.e_path, exp, exp);
        }
        if (strlen(exp) >= sizeof(ee.e_hostname)) {
                syntaxerr("client name too long");
@@ -129,6 +127,9 @@ getexportent(int fromkernel)
        strncpy(ee.e_hostname, exp, sizeof (ee.e_hostname) - 1);
        ee.e_hostname[sizeof (ee.e_hostname) - 1] = '\0';
 
+       if (parseopts(opt, &ee) < 0)
+               return NULL;
+
        /* resolve symlinks */
        if (realpath(ee.e_path, rpath) != NULL) {
                rpath[sizeof (rpath) - 1] = '\0';
@@ -266,7 +267,7 @@ mkexportent(char *hname, char *path, char *options)
        ee.e_path[sizeof (ee.e_path) - 1] = '\0';
        strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
        ee.m_path [sizeof (ee.m_path) - 1] = '\0';
-       if (options && parseopts(options, &ee) < 0)
+       if (parseopts(options, &ee) < 0)
                return NULL;
        return &ee;
 }
@@ -274,7 +275,7 @@ mkexportent(char *hname, char *path, char *options)
 int
 updateexportent(struct exportent *eep, char *options)
 {
-       if (options && parseopts(options, eep) < 0)
+       if (parseopts(options, eep) < 0)
                return 0;
        return 1;
 }
@@ -285,12 +286,17 @@ updateexportent(struct exportent *eep, char *options)
 static int
 parseopts(char *cp, struct exportent *ep)
 {
+       int     had_sync_opt = 0;
 
        squids = ep->e_squids; nsquids = ep->e_nsquids;
        sqgids = ep->e_sqgids; nsqgids = ep->e_nsqgids;
 
+       if (!cp)
+               goto out;
+
        while (isblank(*cp))
                cp++;
+
        while (*cp) {
                char *opt = strdup(cp);
                char *optstart = cp;
@@ -310,11 +316,13 @@ parseopts(char *cp, struct exportent *ep)
                        ep->e_flags &= ~NFSEXP_INSECURE_PORT;
                else if (!strcmp(opt, "insecure"))
                        ep->e_flags |= NFSEXP_INSECURE_PORT;
-               else if (!strcmp(opt, "sync"))
+               else if (!strcmp(opt, "sync")) {
+                       had_sync_opt = 1;
                        ep->e_flags &= ~NFSEXP_ASYNC;
-               else if (!strcmp(opt, "async"))
+               } else if (!strcmp(opt, "async")) {
+                       had_sync_opt = 1;
                        ep->e_flags |= NFSEXP_ASYNC;
-               else if (!strcmp(opt, "nohide"))
+               } else if (!strcmp(opt, "nohide"))
                        ep->e_flags |= NFSEXP_CROSSMNT;
                else if (!strcmp(opt, "hide"))
                        ep->e_flags &= ~NFSEXP_CROSSMNT;
@@ -383,6 +391,13 @@ parseopts(char *cp, struct exportent *ep)
        ep->e_nsquids = nsquids;
        ep->e_nsqgids = nsqgids;
 
+out:
+       if (!had_sync_opt)
+               xlog(L_WARNING, "No 'sync' or 'async' option specified for export \"%s:%s\".\n"
+                               "  Assuming default behaviour ('sync').\n"
+                               "  NOTE: this default has changed from previous versions\n",
+                               ep->e_hostname, ep->e_path);
+
        return 1;
 }
 

diff --git a/utils/exportfs/exports.man b/utils/exportfs/exports.man
index 5dcc809361d6002df79eb3f76b0f43392116b832..97264cdc6511880f69ed3d00a0c092043b1abffd 100644 (file)
--- a/utils/exportfs/exports.man
+++ b/utils/exportfs/exports.man
@@ -95,17 +95,31 @@ 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