Commit a319bf56 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

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: default avatarIlya Dryomov <idryomov@gmail.com>
Reviewed-by: default avatarAlex Elder <elder@linaro.org>
parent d50c97b5

drivers/block/rbd.c

+3 −2
Original line number Diff line number Diff line
@@ -4963,8 +4963,8 @@ out_err: 
 */

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 @@ again: 
		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

+2 −2
Original line number Diff line number Diff line
@@ -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

+6 −6
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE