#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>
static int matchhostname(const char *hostname1, const char *hostname2);
static void export_d_read(const char *dname);
+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.
+ */
+void
+grab_lockfile()
+{
+ _lockfd = open(lockfile, O_CREAT|O_RDWR, 0666);
+ if (_lockfd != -1)
+ lockf(_lockfd, F_LOCK, 0);
+}
+void
+release_lockfile()
+{
+ if (_lockfd != -1)
+ lockf(_lockfd, F_ULOCK, 0);
+}
+
int
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);
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)) {
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++) {
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;
}
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));
}