libceph: osd_request_timeout option

osd_request_timeout specifies how many seconds to wait for a response
from OSDs before returning -ETIMEDOUT from an OSD request.  0 (default)
means no limit.

osd_request_timeout is osdkeepalive-precise -- in-flight requests are
swept through every osdkeepalive seconds.  With ack vs commit behaviour
gone, abort_request() is really simple.

This is based on a patch from Artur Molchanov <artur.molchanov@synesis.ru>.

Tested-by: Artur Molchanov <artur.molchanov@synesis.ru>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

4 files changed, 53 insertions, 1 deletions

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 1816c5e26581..88cd5dc8e238 100644
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -48,6 +48,7 @@ struct ceph_options {
         unsigned long mount_timeout;            /* jiffies */
         unsigned long osd_idle_ttl;             /* jiffies */
         unsigned long osd_keepalive_timeout;    /* jiffies */
+        unsigned long osd_request_timeout;      /* jiffies */
 
         /*
          * any type that can't be simply compared or doesn't need need
@@ -68,6 +69,7 @@ struct ceph_options {
 #define CEPH_MOUNT_TIMEOUT_DEFAULT      msecs_to_jiffies(60 * 1000)
 #define CEPH_OSD_KEEPALIVE_DEFAULT      msecs_to_jiffies(5 * 1000)
 #define CEPH_OSD_IDLE_TTL_DEFAULT       msecs_to_jiffies(60 * 1000)
+#define CEPH_OSD_REQUEST_TIMEOUT_DEFAULT 0  /* no timeout */
 
 #define CEPH_MONC_HUNT_INTERVAL         msecs_to_jiffies(3 * 1000)
 #define CEPH_MONC_PING_INTERVAL         msecs_to_jiffies(10 * 1000)
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 2ea0c282f3dc..c125b5d9e13c 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -189,6 +189,7 @@ struct ceph_osd_request {
 
         /* internal */
         unsigned long r_stamp;                /* jiffies, send or check time */
+        unsigned long r_start_stamp;          /* jiffies */
         int r_attempts;
         struct ceph_eversion r_replay_version; /* aka reassert_version */
         u32 r_last_force_resend;
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 464e88599b9d..108533859a53 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -230,6 +230,7 @@ enum {
         Opt_osdkeepalivetimeout,
         Opt_mount_timeout,
         Opt_osd_idle_ttl,
+        Opt_osd_request_timeout,
         Opt_last_int,
         /* int args above */
         Opt_fsid,
@@ -256,6 +257,7 @@ static match_table_t opt_tokens = {
         {Opt_osdkeepalivetimeout, "osdkeepalive=%d"},
         {Opt_mount_timeout, "mount_timeout=%d"},
         {Opt_osd_idle_ttl, "osd_idle_ttl=%d"},
+        {Opt_osd_request_timeout, "osd_request_timeout=%d"},
         /* int args above */
         {Opt_fsid, "fsid=%s"},
         {Opt_name, "name=%s"},
@@ -361,6 +363,7 @@ ceph_parse_options(char *options, const char *dev_name,
         opt->osd_keepalive_timeout = CEPH_OSD_KEEPALIVE_DEFAULT;
         opt->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT;
         opt->osd_idle_ttl = CEPH_OSD_IDLE_TTL_DEFAULT;
+        opt->osd_request_timeout = CEPH_OSD_REQUEST_TIMEOUT_DEFAULT;
 
         /* get mon ip(s) */
         /* ip1[:port1][,ip2[:port2]...] */
@@ -473,6 +476,15 @@ ceph_parse_options(char *options, const char *dev_name,
                         }
                         opt->mount_timeout = msecs_to_jiffies(intval * 1000);
                         break;
+                case Opt_osd_request_timeout:
+                        /* 0 is "wait forever" (i.e. infinite timeout) */
+                        if (intval < 0 || intval > INT_MAX / 1000) {
+                                pr_err("osd_request_timeout out of range\n");
+                                err = -EINVAL;
+                                goto out;
+                        }
+                        opt->osd_request_timeout = msecs_to_jiffies(intval * 1000);
+                        break;
 
                 case Opt_share:
                         opt->flags &= ~CEPH_OPT_NOSHARE;
@@ -557,6 +569,9 @@ int ceph_print_client_options(struct seq_file *m, struct ceph_client *client)
         if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
                 seq_printf(m, "osdkeepalivetimeout=%d,",
                     jiffies_to_msecs(opt->osd_keepalive_timeout) / 1000);
+        if (opt->osd_request_timeout != CEPH_OSD_REQUEST_TIMEOUT_DEFAULT)
+                seq_printf(m, "osd_request_timeout=%d,",
+                           jiffies_to_msecs(opt->osd_request_timeout) / 1000);
 
         /* drop redundant comma */
         if (m->count != pos)
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index b65bbf9f45eb..e15ea9e4c495 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1709,6 +1709,8 @@ static void account_request(struct ceph_osd_request *req)
 
         req->r_flags |= CEPH_OSD_FLAG_ONDISK;
         atomic_inc(&req->r_osdc->num_requests);
+
+        req->r_start_stamp = jiffies;
 }
 
 static void submit_request(struct ceph_osd_request *req, bool wrlocked)
@@ -1789,6 +1791,14 @@ static void cancel_request(struct ceph_osd_request *req)
         ceph_osdc_put_request(req);
 }
 
+static void abort_request(struct ceph_osd_request *req, int err)
+{
+        dout("%s req %p tid %llu err %d\n", __func__, req, req->r_tid, err);
+
+        cancel_map_check(req);
+        complete_request(req, err);
+}
+
 static void check_pool_dne(struct ceph_osd_request *req)
 {
         struct ceph_osd_client *osdc = req->r_osdc;
@@ -2487,6 +2497,7 @@ static void handle_timeout(struct work_struct *work)
                 container_of(work, struct ceph_osd_client, timeout_work.work);
         struct ceph_options *opts = osdc->client->options;
         unsigned long cutoff = jiffies - opts->osd_keepalive_timeout;
+        unsigned long expiry_cutoff = jiffies - opts->osd_request_timeout;
         LIST_HEAD(slow_osds);
         struct rb_node *n, *p;
 
@@ -2502,15 +2513,23 @@ static void handle_timeout(struct work_struct *work)
                 struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
                 bool found = false;
 
-                for (p = rb_first(&osd->o_requests); p; p = rb_next(p)) {
+                for (p = rb_first(&osd->o_requests); p; ) {
                         struct ceph_osd_request *req =
                             rb_entry(p, struct ceph_osd_request, r_node);
 
+                        p = rb_next(p); /* abort_request() */
+
                         if (time_before(req->r_stamp, cutoff)) {
                                 dout(" req %p tid %llu on osd%d is laggy\n",
                                      req, req->r_tid, osd->o_osd);
                                 found = true;
                         }
+                        if (opts->osd_request_timeout &&
+                            time_before(req->r_start_stamp, expiry_cutoff)) {
+                                pr_err_ratelimited("tid %llu on osd%d timeout\n",
+                                       req->r_tid, osd->o_osd);
+                                abort_request(req, -ETIMEDOUT);
+                        }
                 }
                 for (p = rb_first(&osd->o_linger_requests); p; p = rb_next(p)) {
                         struct ceph_osd_linger_request *lreq =
@@ -2530,6 +2549,21 @@ static void handle_timeout(struct work_struct *work)
                         list_move_tail(&osd->o_keepalive_item, &slow_osds);
         }
 
+        if (opts->osd_request_timeout) {
+                for (p = rb_first(&osdc->homeless_osd.o_requests); p; ) {
+                        struct ceph_osd_request *req =
+                            rb_entry(p, struct ceph_osd_request, r_node);
+
+                        p = rb_next(p); /* abort_request() */
+
+                        if (time_before(req->r_start_stamp, expiry_cutoff)) {
+                                pr_err_ratelimited("tid %llu on osd%d timeout\n",
+                                       req->r_tid, osdc->homeless_osd.o_osd);
+                                abort_request(req, -ETIMEDOUT);
+                        }
+                }
+        }
+
         if (atomic_read(&osdc->num_homeless) || !list_empty(&slow_osds))
                 maybe_request_map(osdc);