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>

drivers/block/rbd.c

@@ -4963,8 +4963,8 @@ static int rbd_add_parse_args(const char *buf,
  */
 static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
 {
+	struct ceph_options *opts = rbdc->client->options;
 	u64 newest_epoch;
-	unsigned long timeout = rbdc->client->options->mount_timeout * HZ;
 	int tries = 0;
 	int ret;
 
@@ -4979,7 +4979,8 @@ static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
 		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
 			ceph_monc_request_next_osdmap(&rbdc->client->monc);
 			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
-						     newest_epoch, timeout);
+						     newest_epoch,
+						     opts->mount_timeout);
 			goto again;
 		} else {
 			/* the osdmap we have is new enough */

fs/ceph/dir.c

@@ -1260,7 +1260,7 @@ static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
 		if (req->r_timeout) {
 			unsigned long time_left = wait_for_completion_timeout(
 					&req->r_safe_completion,
-							req->r_timeout);
+					ceph_timeout_jiffies(req->r_timeout));
 			if (time_left > 0)
 				ret = 0;
 			else

fs/ceph/mds_client.c

@@ -2268,7 +2268,8 @@ int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 	dout("do_request waiting\n");
 	if (req->r_timeout) {
 		err = (long)wait_for_completion_killable_timeout(
-			&req->r_completion, req->r_timeout);
+					&req->r_completion,
+					ceph_timeout_jiffies(req->r_timeout));
 		if (err == 0)
 			err = -EIO;
 	} else if (req->r_wait_for_completion) {
@@ -3424,8 +3425,8 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc)
  */
 static void wait_requests(struct ceph_mds_client *mdsc)
 {
+	struct ceph_options *opts = mdsc->fsc->client->options;
 	struct ceph_mds_request *req;
-	struct ceph_fs_client *fsc = mdsc->fsc;
 
 	mutex_lock(&mdsc->mutex);
 	if (__get_oldest_req(mdsc)) {
@@ -3433,7 +3434,7 @@ static void wait_requests(struct ceph_mds_client *mdsc)
 
 		dout("wait_requests waiting for requests\n");
 		wait_for_completion_timeout(&mdsc->safe_umount_waiters,
-				    fsc->client->options->mount_timeout * HZ);
+				    ceph_timeout_jiffies(opts->mount_timeout));
 
 		/* tear down remaining requests */
 		mutex_lock(&mdsc->mutex);
@@ -3556,10 +3557,9 @@ static bool done_closing_sessions(struct ceph_mds_client *mdsc)
  */
 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
 {
+	struct ceph_options *opts = mdsc->fsc->client->options;
 	struct ceph_mds_session *session;
 	int i;
-	struct ceph_fs_client *fsc = mdsc->fsc;
-	unsigned long timeout = fsc->client->options->mount_timeout * HZ;
 
 	dout("close_sessions\n");
 
@@ -3580,7 +3580,7 @@ void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
 
 	dout("waiting for sessions to close\n");
 	wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
-			   timeout);
+			   ceph_timeout_jiffies(opts->mount_timeout));
 
 	/* tear down remaining sessions */
 	mutex_lock(&mdsc->mutex);

fs/ceph/mds_client.h

@@ -227,7 +227,7 @@ struct ceph_mds_request {
 	int r_err;
 	bool r_aborted;
 
-	unsigned long r_timeout;  /* optional.  jiffies */
+	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 	unsigned long r_started;  /* start time to measure timeout against */
 	unsigned long r_request_started; /* start time for mds request only,
 					    used to measure lease durations */

fs/ceph/super.c

@@ -742,7 +742,7 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
 	req->r_ino1.ino = CEPH_INO_ROOT;
 	req->r_ino1.snap = CEPH_NOSNAP;
 	req->r_started = started;
-	req->r_timeout = fsc->client->options->mount_timeout * HZ;
+	req->r_timeout = fsc->client->options->mount_timeout;
 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
 	req->r_num_caps = 2;
 	err = ceph_mdsc_do_request(mdsc, NULL, req);

include/linux/ceph/libceph.h

@@ -43,9 +43,9 @@ struct ceph_options {
 	int flags;
 	struct ceph_fsid fsid;
 	struct ceph_entity_addr my_addr;
-	int mount_timeout;
+	unsigned long mount_timeout;		/* jiffies */
-	int osd_idle_ttl;
+	unsigned long osd_idle_ttl;		/* jiffies */
-	int osd_keepalive_timeout;
+	unsigned long osd_keepalive_timeout;	/* jiffies */
 
 	/*
 	 * any type that can't be simply compared or doesn't need need
@@ -63,9 +63,9 @@ struct ceph_options {
 /*
  * defaults
  */
-#define CEPH_MOUNT_TIMEOUT_DEFAULT  60
+#define CEPH_MOUNT_TIMEOUT_DEFAULT	msecs_to_jiffies(60 * 1000)
-#define CEPH_OSD_KEEPALIVE_DEFAULT  5
+#define CEPH_OSD_KEEPALIVE_DEFAULT	msecs_to_jiffies(5 * 1000)
-#define CEPH_OSD_IDLE_TTL_DEFAULT    60
+#define CEPH_OSD_IDLE_TTL_DEFAULT	msecs_to_jiffies(60 * 1000)
 
 #define CEPH_MSG_MAX_FRONT_LEN	(16*1024*1024)
 #define CEPH_MSG_MAX_MIDDLE_LEN	(16*1024*1024)
@@ -93,6 +93,11 @@ enum {
 	CEPH_MOUNT_SHUTDOWN,
 };
 
+static inline unsigned long ceph_timeout_jiffies(unsigned long timeout)
+{
+	return timeout ?: MAX_SCHEDULE_TIMEOUT;
+}
+
 struct ceph_mds_client;
 
 /*

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->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT;
-	opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT;   /* seconds */
+	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)

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;
 

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 =
+	unsigned long delay = osdc->client->options->osd_idle_ttl / 4;
-		osdc->client->options->osd_idle_ttl * HZ >> 2;
 
 	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,