From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
Use the self-pipe trick instead.
(Alternatively, we could use ppoll. That wasn't supported before
2.6.16, whereas gss was introduced in 2.5. I was trying to be
conservative about compatibility with older kernels, but maybe we don't
care at this point.)
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
utils/gssd/gssd_main_loop.c | 52 +++++++++++++++++++++++++------------------
1 file changed, 30 insertions(+), 22 deletions(-)
diff --git a/utils/gssd/gssd_main_loop.c b/utils/gssd/gssd_main_loop.c
index c18e12c..8886eb6 100644
--- a/utils/gssd/gssd_main_loop.c
+++ b/utils/gssd/gssd_main_loop.c
@@ -57,15 +57,18 @@
extern struct pollfd *pollarray;
extern int pollsize;
-#define POLL_MILLISECS 500
+static int pipefd[2];
-static volatile int dir_changed = 1;
+static void something_changed(void)
+{
+ if (1 != write(pipefd[1], "!", 1))
+ printerr(2, "weird; maybe an interrupt?");
+}
static void dir_notify_handler(int sig, siginfo_t *si, void *data)
{
printerr(2, "dir_notify_handler: sig %d si %p data %p\n", sig, si, data);
-
- dir_changed = 1;
+ something_changed();
}
static void
@@ -80,7 +83,7 @@ scan_poll_results(int ret)
if (i >= 0 && pollarray[i].revents) {
if (pollarray[i].revents & POLLHUP) {
clp->gssd_close_me = 1;
- dir_changed = 1;
+ something_changed();
}
if (pollarray[i].revents & POLLIN)
handle_gssd_upcall(clp);
@@ -93,7 +96,7 @@ scan_poll_results(int ret)
if (i >= 0 && pollarray[i].revents) {
if (pollarray[i].revents & POLLHUP) {
clp->krb5_close_me = 1;
- dir_changed = 1;
+ something_changed();
}
if (pollarray[i].revents & POLLIN)
handle_krb5_upcall(clp);
@@ -123,11 +126,13 @@ topdirs_add_entry(struct dirent *dent)
}
snprintf(tdi->dirname, PATH_MAX, "%s/%s", pipefs_dir, dent->d_name);
tdi->fd = open(tdi->dirname, O_RDONLY);
- if (tdi->fd != -1) {
- fcntl(tdi->fd, F_SETSIG, DNOTIFY_SIGNAL);
- fcntl(tdi->fd, F_NOTIFY,
- DN_CREATE|DN_DELETE|DN_MODIFY|DN_MULTISHOT);
+ if (tdi->fd == -1) {
+ printerr(0, "ERROR: failed to open %s\n", tdi->dirname);
+ free(tdi);
+ return -1;
}
+ fcntl(tdi->fd, F_SETSIG, DNOTIFY_SIGNAL);
+ fcntl(tdi->fd, F_NOTIFY, DN_CREATE|DN_DELETE|DN_MODIFY|DN_MULTISHOT);
TAILQ_INSERT_HEAD(&topdirs_list, tdi, list);
return 0;
@@ -185,6 +190,7 @@ gssd_run()
int ret;
struct sigaction dn_act;
sigset_t set;
+ char buf;
/* Taken from linux/Documentation/dnotify.txt: */
dn_act.sa_sigaction = dir_notify_handler;
@@ -202,26 +208,28 @@ gssd_run()
init_client_list();
+ ret = pipe2(pipefd, O_NONBLOCK);
+ if (ret == -1)
+ return;
+ pollarray[0].fd = pipefd[0];
+ pollarray[0].events = POLLIN;
+
printerr(1, "beginning poll\n");
while (1) {
- while (dir_changed) {
- dir_changed = 0;
- if (update_client_list()) {
- /* Error msg is already printed */
- exit(1);
- }
- }
- /* race condition here: dir_changed could be set before we
- * enter the poll, and we'd never notice if it weren't for the
- * timeout. */
- ret = poll(pollarray, pollsize, POLL_MILLISECS);
+ ret = poll(pollarray, pollsize, -1);
if (ret < 0) {
if (errno != EINTR)
printerr(0,
"WARNING: error return from poll\n");
} else if (ret == 0) {
- /* timeout */
+ /* timeout?? */
} else { /* ret > 0 */
+ if (pollarray[0].revents) {
+ if (1 != read(pipefd[0], &buf, 1))
+ printerr(2, "weird; maybe an interrupt?");
+ if (update_client_list())
+ exit(1);
+ }
scan_poll_results(ret);
}
}
--
1.7.9.5
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