X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fnfsdcld%2Fnfsdcld.c;h=6a1eba8f7d3214ecfbd78f1dc7f6ae34bf644e58;hp=2d118681abbb5f11809898a072cbea1a5d944bf1;hb=b9f64af3b83a2916c5b6cd65fe011acc436942d4;hpb=09d9011c66e518ca7fd01d41607845b940f58c8f

diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
index 2d11868..6a1eba8 100644
--- a/utils/nfsdcld/nfsdcld.c
+++ b/utils/nfsdcld/nfsdcld.c
@@ -32,6 +32,8 @@
 #include <sys/types.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <libgen.h>
+#include <sys/inotify.h>
 
 #include "xlog.h"
 #include "nfslib.h"
@@ -54,6 +56,8 @@ struct cld_client {
 
 /* global variables */
 static char *pipepath = DEFAULT_CLD_PATH;
+static int 		inotify_fd = -1;
+static struct event	pipedir_event;
 
 static struct option longopts[] =
 {
@@ -74,6 +78,8 @@ usage(char *progname)
 	printf("%s [ -hFd ] [ -p pipe ] [ -s dir ]\n", progname);
 }
 
+#define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX)
+
 static int
 cld_pipe_open(struct cld_client *clnt)
 {
@@ -97,18 +103,149 @@ cld_pipe_open(struct cld_client *clnt)
 	return 0;
 }
 
+static void
+cld_inotify_cb(int UNUSED(fd), short which, void *data)
+{
+	int ret;
+	size_t elen;
+	ssize_t rret;
+	char evbuf[INOTIFY_EVENT_MAX];
+	char *dirc = NULL, *pname;
+	struct inotify_event *event = (struct inotify_event *)evbuf;
+	struct cld_client *clnt = data;
+
+	if (which != EV_READ)
+		return;
+
+	xlog(D_GENERAL, "%s: called for EV_READ", __func__);
+
+	dirc = strndup(pipepath, PATH_MAX);
+	if (!dirc) {
+		xlog(L_ERROR, "%s: unable to allocate memory", __func__);
+		goto out;
+	}
+
+	rret = read(inotify_fd, evbuf, INOTIFY_EVENT_MAX);
+	if (rret < 0) {
+		xlog(L_ERROR, "%s: read from inotify fd failed: %m", __func__);
+		goto out;
+	}
+
+	/* check to see if we have a filename in the evbuf */
+	if (!event->len) {
+		xlog(D_GENERAL, "%s: no filename in inotify event", __func__);
+		goto out;
+	}
+
+	pname = basename(dirc);
+	elen = strnlen(event->name, event->len);
+
+	/* does the filename match our pipe? */
+	if (strlen(pname) != elen || memcmp(pname, event->name, elen)) {
+		xlog(D_GENERAL, "%s: wrong filename (%s)", __func__,
+				event->name);
+		goto out;
+	}
+
+	ret = cld_pipe_open(clnt);
+	switch (ret) {
+	case 0:
+		/* readd the event for the cl_event pipe */
+		event_add(&clnt->cl_event, NULL);
+		break;
+	case -ENOENT:
+		/* pipe must have disappeared, wait for it to come back */
+		goto out;
+	default:
+		/* anything else is fatal */
+		xlog(L_FATAL, "%s: unable to open new pipe (%d). Aborting.",
+			ret, __func__);
+		exit(ret);
+	}
+
+out:
+	event_add(&pipedir_event, NULL);
+	free(dirc);
+}
+
+static int
+cld_inotify_setup(void)
+{
+	int ret;
+	char *dirc, *dname;
+
+	dirc = strndup(pipepath, PATH_MAX);
+	if (!dirc) {
+		xlog_err("%s: unable to allocate memory", __func__);
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	dname = dirname(dirc);
+
+	inotify_fd = inotify_init();
+	if (inotify_fd < 0) {
+		xlog_err("%s: inotify_init failed: %m", __func__);
+		ret = -errno;
+		goto out_free;
+	}
+
+	ret = inotify_add_watch(inotify_fd, dname, IN_CREATE);
+	if (ret < 0) {
+		xlog_err("%s: inotify_add_watch failed: %m", __func__);
+		ret = -errno;
+		goto out_err;
+	}
+
+out_free:
+	free(dirc);
+	return 0;
+out_err:
+	close(inotify_fd);
+	goto out_free;
+}
+
+/*
+ * Set an inotify watch on the directory that should contain the pipe, and then
+ * try to open it. If it fails with anything but -ENOENT, return the error
+ * immediately.
+ *
+ * If it succeeds, then set up the pipe event handler. At that point, set up
+ * the inotify event handler and go ahead and return success.
+ */
 static int
 cld_pipe_init(struct cld_client *clnt)
 {
 	int ret;
 
+	xlog(D_GENERAL, "%s: init pipe handlers", __func__);
+
+	ret = cld_inotify_setup();
+	if (ret != 0)
+		goto out;
+
 	clnt->cl_fd = -1;
 	ret = cld_pipe_open(clnt);
-	if (ret)
-		return ret;
+	switch (ret) {
+	case 0:
+		/* add the event and we're good to go */
+		event_add(&clnt->cl_event, NULL);
+		break;
+	case -ENOENT:
+		/* ignore this error -- cld_inotify_cb will handle it */
+		ret = 0;
+		break;
+	default:
+		/* anything else is fatal */
+		close(inotify_fd);
+		goto out;
+	}
 
-	event_add(&clnt->cl_event, NULL);
-	return 0;
+	/* set event for inotify read */
+	event_set(&pipedir_event, inotify_fd, EV_READ, cld_inotify_cb, clnt);
+	event_add(&pipedir_event, NULL);
+out:
+	return ret;
 }
 
 static void
@@ -382,6 +519,7 @@ main(int argc, char **argv)
 		xlog(L_ERROR, "%s: event_dispatch failed: %m", __func__);
 
 	close(clnt.cl_fd);
+	close(inotify_fd);
 out:
 	free(progname);
 	return rc;