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>

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 1816c5e..88cd5dc 100644 (file)
--- 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 2ea0c28..c125b5d 100644 (file)
--- 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 464e885..1085338 100644 (file)
--- 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 b65bbf9..e15ea9e 100644 (file)
--- 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);