exportfs: Removed warnings about routines not being prototyped

[nfs-utils.git] / utils / exportfs / exportfs.c

diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
index 12e8bf112dd414259ffec3d749497125c5c469b2..a3323d733efb01c05a48c9bed8ae37f6dc40385d 100644 (file)
--- a/utils/exportfs/exportfs.c
+++ b/utils/exportfs/exportfs.c
@@ -16,6 +16,7 @@
 #include <sys/stat.h>
 #include <sys/vfs.h>
 #include <sys/stat.h>
+#include <sys/file.h>
 #include <unistd.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -43,6 +44,41 @@ static void  usage(const char *progname);
 static void    validate_export(nfs_export *exp);
 static int     matchhostname(const char *hostname1, const char *hostname2);
 static void    export_d_read(const char *dname);
+static void grab_lockfile(void);
+static void release_lockfile(void);
+
+static const char *lockfile = EXP_LOCKFILE;
+static int _lockfd = -1;
+
+/*
+ * If we aren't careful, changes made by exportfs can be lost
+ * when multiple exports process run at once:
+ *
+ *     exportfs process 1      exportfs process 2
+ *     ------------------------------------------
+ *     reads etab version A    reads etab version A
+ *     adds new export B       adds new export C
+ *     writes A+B              writes A+C
+ *
+ * The locking in support/export/xtab.c will prevent mountd from
+ * seeing a partially written version of etab, and will prevent 
+ * the two writers above from writing simultaneously and
+ * corrupting etab, but to prevent problems like the above we
+ * need these additional lockfile() routines.
+ */
+static void 
+grab_lockfile()
+{
+       _lockfd = open(lockfile, O_CREAT|O_RDWR, 0666);
+       if (_lockfd != -1) 
+               lockf(_lockfd, F_LOCK, 0);
+}
+static void 
+release_lockfile()
+{
+       if (_lockfd != -1)
+               lockf(_lockfd, F_ULOCK, 0);
+}
 
 int
 main(int argc, char **argv)
@@ -129,6 +165,13 @@ main(int argc, char **argv)
                        return 0;
                }
        }
+
+       /*
+        * Serialize things as best we can
+        */
+       grab_lockfile();
+       atexit(release_lockfile);
+
        if (f_export && ! f_ignore) {
                export_read(_PATH_EXPORTS);
                export_d_read(_PATH_EXPORTS_D);
@@ -401,7 +444,7 @@ validate_export(nfs_export *exp)
        int fs_has_fsid = 0;
 
        if (stat(path, &stb) < 0) {
-               xlog(L_ERROR, "Failed to stat %s: %m \n", path);
+               xlog(L_ERROR, "Failed to stat %s: %m", path);
                return;
        }
        if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
@@ -529,9 +572,12 @@ export_d_read(const char *dname)
 
 
        n = scandir(dname, &namelist, NULL, versionsort);
-       if (n < 0)
-               xlog(L_NOTICE, "scandir %s: %s\n", dname, strerror(errno));
-       else if (n == 0)
+       if (n < 0) {
+               if (errno == ENOENT)
+                       /* Silently return */
+                       return;
+               xlog(L_NOTICE, "scandir %s: %s", dname, strerror(errno));
+       } else if (n == 0)
                return;
 
        for (i = 0; i < n; i++) {
@@ -558,7 +604,7 @@ export_d_read(const char *dname)
 
                fname_len = snprintf(fname, PATH_MAX +1, "%s/%s", dname, d->d_name);
                if (fname_len > PATH_MAX) {
-                       xlog(L_WARNING, "Too long file name: %s in %s\n", d->d_name, dname);
+                       xlog(L_WARNING, "Too long file name: %s in %s", d->d_name, dname);
                        continue;
                }
 
@@ -672,7 +718,7 @@ dump(int verbose)
 static void
 error(nfs_export *exp, int err)
 {
-       xlog(L_ERROR, "%s:%s: %s\n", exp->m_client->m_hostname,
+       xlog(L_ERROR, "%s:%s: %s", exp->m_client->m_hostname,
                exp->m_export.e_path, strerror(err));
 }