libceph: store timeouts in jiffies, verify user input

There are currently three libceph-level timeouts that the user can
specify on mount: mount_timeout, osd_idle_ttl and osdkeepalive.  All of
these are in seconds and no checking is done on user input: negative
values are accepted, we multiply them all by HZ which may or may not
overflow, arbitrarily large jiffies then get added together, etc.

There is also a bug in the way mount_timeout=0 is handled.  It's
supposed to mean "infinite timeout", but that's not how wait.h APIs
treat it and so __ceph_open_session() for example will busy loop
without much chance of being interrupted if none of ceph-mons are
there.

Fix all this by verifying user input, storing timeouts capped by
msecs_to_jiffies() in jiffies and using the new ceph_timeout_jiffies()
helper for all user-specified waits to handle infinite timeouts
correctly.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>

3 files changed, 47 insertions, 20 deletions

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 79e8f71..a80e91c 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -352,8 +352,8 @@ ceph_parse_options(char *options, const char *dev_name,
 	/* start with defaults */
 	opt->flags = CEPH_OPT_DEFAULT;
 	opt->osd_keepalive_timeout = CEPH_OSD_KEEPALIVE_DEFAULT;
-	opt->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT; /* seconds */
-	opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT;   /* seconds */
+	opt->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT;
+	opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT;
 
 	/* get mon ip(s) */
 	/* ip1[:port1][,ip2[:port2]...] */
@@ -439,13 +439,32 @@ ceph_parse_options(char *options, const char *dev_name,
 			pr_warn("ignoring deprecated osdtimeout option\n");
 			break;
 		case Opt_osdkeepalivetimeout:
-			opt->osd_keepalive_timeout = intval;
+			/* 0 isn't well defined right now, reject it */
+			if (intval < 1 || intval > INT_MAX / 1000) {
+				pr_err("osdkeepalive out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->osd_keepalive_timeout =
+					msecs_to_jiffies(intval * 1000);
 			break;
 		case Opt_osd_idle_ttl:
-			opt->osd_idle_ttl = intval;
+			/* 0 isn't well defined right now, reject it */
+			if (intval < 1 || intval > INT_MAX / 1000) {
+				pr_err("osd_idle_ttl out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->osd_idle_ttl = msecs_to_jiffies(intval * 1000);
 			break;
 		case Opt_mount_timeout:
-			opt->mount_timeout = intval;
+			/* 0 is "wait forever" (i.e. infinite timeout) */
+			if (intval < 0 || intval > INT_MAX / 1000) {
+				pr_err("mount_timeout out of range\n");
+				err = -EINVAL;
+				goto out;
+			}
+			opt->mount_timeout = msecs_to_jiffies(intval * 1000);
 			break;
 
 		case Opt_share:
@@ -512,12 +531,14 @@ int ceph_print_client_options(struct seq_file *m, struct ceph_client *client)
 		seq_puts(m, "notcp_nodelay,");
 
 	if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
-		seq_printf(m, "mount_timeout=%d,", opt->mount_timeout);
+		seq_printf(m, "mount_timeout=%d,",
+			   jiffies_to_msecs(opt->mount_timeout) / 1000);
 	if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
-		seq_printf(m, "osd_idle_ttl=%d,", opt->osd_idle_ttl);
+		seq_printf(m, "osd_idle_ttl=%d,",
+			   jiffies_to_msecs(opt->osd_idle_ttl) / 1000);
 	if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
 		seq_printf(m, "osdkeepalivetimeout=%d,",
-			   opt->osd_keepalive_timeout);
+		    jiffies_to_msecs(opt->osd_keepalive_timeout) / 1000);
 
 	/* drop redundant comma */
 	if (m->count != pos)
@@ -627,7 +648,7 @@ static int have_mon_and_osd_map(struct ceph_client *client)
 int __ceph_open_session(struct ceph_client *client, unsigned long started)
 {
 	int err;
-	unsigned long timeout = client->options->mount_timeout * HZ;
+	unsigned long timeout = client->options->mount_timeout;
 
 	/* open session, and wait for mon and osd maps */
 	err = ceph_monc_open_session(&client->monc);
@@ -643,7 +664,7 @@ int __ceph_open_session(struct ceph_client *client, unsigned long started)
 		dout("mount waiting for mon_map\n");
 		err = wait_event_interruptible_timeout(client->auth_wq,
 			have_mon_and_osd_map(client) || (client->auth_err < 0),
-			timeout);
+			ceph_timeout_jiffies(timeout));
 		if (err == -EINTR || err == -ERESTARTSYS)
 			return err;
 		if (client->auth_err < 0)
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 2b3cf05..0da3bdc 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -298,6 +298,12 @@ void ceph_monc_request_next_osdmap(struct ceph_mon_client *monc)
 }
 EXPORT_SYMBOL(ceph_monc_request_next_osdmap);
 
+/*
+ * Wait for an osdmap with a given epoch.
+ *
+ * @epoch: epoch to wait for
+ * @timeout: in jiffies, 0 means "wait forever"
+ */
 int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
 			  unsigned long timeout)
 {
@@ -308,11 +314,12 @@ int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
 	while (monc->have_osdmap < epoch) {
 		mutex_unlock(&monc->mutex);
 
-		if (timeout != 0 && time_after_eq(jiffies, started + timeout))
+		if (timeout && time_after_eq(jiffies, started + timeout))
 			return -ETIMEDOUT;
 
 		ret = wait_event_interruptible_timeout(monc->client->auth_wq,
-					 monc->have_osdmap >= epoch, timeout);
+						monc->have_osdmap >= epoch,
+						ceph_timeout_jiffies(timeout));
 		if (ret < 0)
 			return ret;
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 4cb4fab..5003367 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1097,7 +1097,7 @@ static void __move_osd_to_lru(struct ceph_osd_client *osdc,
 	BUG_ON(!list_empty(&osd->o_osd_lru));
 
 	list_add_tail(&osd->o_osd_lru, &osdc->osd_lru);
-	osd->lru_ttl = jiffies + osdc->client->options->osd_idle_ttl * HZ;
+	osd->lru_ttl = jiffies + osdc->client->options->osd_idle_ttl;
 }
 
 static void maybe_move_osd_to_lru(struct ceph_osd_client *osdc,
@@ -1208,7 +1208,7 @@ static struct ceph_osd *__lookup_osd(struct ceph_osd_client *osdc, int o)
 static void __schedule_osd_timeout(struct ceph_osd_client *osdc)
 {
 	schedule_delayed_work(&osdc->timeout_work,
-			osdc->client->options->osd_keepalive_timeout * HZ);
+			      osdc->client->options->osd_keepalive_timeout);
 }
 
 static void __cancel_osd_timeout(struct ceph_osd_client *osdc)
@@ -1576,10 +1576,9 @@ static void handle_timeout(struct work_struct *work)
 {
 	struct ceph_osd_client *osdc =
 		container_of(work, struct ceph_osd_client, timeout_work.work);
+	struct ceph_options *opts = osdc->client->options;
 	struct ceph_osd_request *req;
 	struct ceph_osd *osd;
-	unsigned long keepalive =
-		osdc->client->options->osd_keepalive_timeout * HZ;
 	struct list_head slow_osds;
 	dout("timeout\n");
 	down_read(&osdc->map_sem);
@@ -1595,7 +1594,8 @@ static void handle_timeout(struct work_struct *work)
 	 */
 	INIT_LIST_HEAD(&slow_osds);
 	list_for_each_entry(req, &osdc->req_lru, r_req_lru_item) {
-		if (time_before(jiffies, req->r_stamp + keepalive))
+		if (time_before(jiffies,
+				req->r_stamp + opts->osd_keepalive_timeout))
 			break;
 
 		osd = req->r_osd;
@@ -1622,8 +1622,7 @@ static void handle_osds_timeout(struct work_struct *work)
 	struct ceph_osd_client *osdc =
 		container_of(work, struct ceph_osd_client,
 			     osds_timeout_work.work);
-	unsigned long delay =
-		osdc->client->options->osd_idle_ttl * HZ >> 2;
+	unsigned long delay = osdc->client->options->osd_idle_ttl / 4;
 
 	dout("osds timeout\n");
 	down_read(&osdc->map_sem);
@@ -2628,7 +2627,7 @@ int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
 	osdc->event_count = 0;
 
 	schedule_delayed_work(&osdc->osds_timeout_work,
-	   round_jiffies_relative(osdc->client->options->osd_idle_ttl * HZ));
+	    round_jiffies_relative(osdc->client->options->osd_idle_ttl));
 
 	err = -ENOMEM;
 	osdc->req_mempool = mempool_create_kmalloc_pool(10,