staging: lustre: grant: quiet message on grant waiting timeout

Use at_max in osc_enter_cache() to bound how long we wait for grant
space before switching to synchronous I/Os. Do not print a message
on the console when the timeout is hit since such long wait can
be legitimate with flaky network (i.e. BRW is resent multiple times).

Signed-off-by: Johann Lombardi <johann.lombardi@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5521
Reviewed-on: http://review.whamcloud.com/12146
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c
index adc3b6d065312bdf3daf6720197bbb960587315a..4bbe219add981393989d3d51b192b20b46276a58 100644 (file)
--- a/drivers/staging/lustre/lustre/osc/osc_cache.c
+++ b/drivers/staging/lustre/lustre/osc/osc_cache.c
@@ -1536,7 +1536,7 @@ static int osc_enter_cache_try(struct client_obd *cli,
 {
        int rc;
 
-       OSC_DUMP_GRANT(D_CACHE, cli, "need:%d.\n", bytes);
+       OSC_DUMP_GRANT(D_CACHE, cli, "need:%d\n", bytes);
 
        rc = osc_reserve_grant(cli, bytes);
        if (rc < 0)
@@ -1581,11 +1581,13 @@ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
        struct osc_object *osc = oap->oap_obj;
        struct lov_oinfo *loi = osc->oo_oinfo;
        struct osc_cache_waiter ocw;
-       struct l_wait_info lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(600), NULL,
-                                                 LWI_ON_SIGNAL_NOOP, NULL);
+       struct l_wait_info lwi;
        int rc = -EDQUOT;
 
-       OSC_DUMP_GRANT(D_CACHE, cli, "need:%d.\n", bytes);
+       lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(AT_OFF ? obd_timeout : at_max),
+                              NULL, LWI_ON_SIGNAL_NOOP, NULL);
+
+       OSC_DUMP_GRANT(D_CACHE, cli, "need:%d\n", bytes);
 
        spin_lock(&cli->cl_loi_list_lock);
 
@@ -1595,12 +1597,14 @@ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
        if (OBD_FAIL_CHECK(OBD_FAIL_OSC_NO_GRANT) ||
            !cli->cl_dirty_max_pages || cli->cl_ar.ar_force_sync ||
            loi->loi_ar.ar_force_sync) {
+               OSC_DUMP_GRANT(D_CACHE, cli, "forced sync i/o\n");
                rc = -EDQUOT;
                goto out;
        }
 
        /* Hopefully normal case - cache space and write credits available */
        if (osc_enter_cache_try(cli, oap, bytes, 0)) {
+               OSC_DUMP_GRANT(D_CACHE, cli, "granted from cache\n");
                rc = 0;
                goto out;
        }
@@ -1629,32 +1633,49 @@ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
 
                spin_lock(&cli->cl_loi_list_lock);
 
-               /* l_wait_event is interrupted by signal, or timed out */
                if (rc < 0) {
-                       if (rc == -ETIMEDOUT) {
-                               OSC_DUMP_GRANT(D_ERROR, cli,
-                                              "try to reserve %d.\n", bytes);
-                               osc_extent_tree_dump(D_ERROR, osc);
-                               rc = -EDQUOT;
-                       }
-
+                       /* l_wait_event is interrupted by signal, or timed out */
                        list_del_init(&ocw.ocw_entry);
-                       goto out;
+                       break;
                }
-
                LASSERT(list_empty(&ocw.ocw_entry));
                rc = ocw.ocw_rc;
 
                if (rc != -EDQUOT)
-                       goto out;
+                       break;
                if (osc_enter_cache_try(cli, oap, bytes, 0)) {
                        rc = 0;
-                       goto out;
+                       break;
                }
        }
+
+       switch (rc) {
+       case 0:
+               OSC_DUMP_GRANT(D_CACHE, cli, "finally got grant space\n");
+               break;
+       case -ETIMEDOUT:
+               OSC_DUMP_GRANT(D_CACHE, cli,
+                              "timeout, fall back to sync i/o\n");
+               osc_extent_tree_dump(D_CACHE, osc);
+               /* fall back to synchronous I/O */
+               rc = -EDQUOT;
+               break;
+       case -EINTR:
+               /* Ensures restartability - LU-3581 */
+               OSC_DUMP_GRANT(D_CACHE, cli, "interrupted\n");
+               rc = -ERESTARTSYS;
+               break;
+       case -EDQUOT:
+               OSC_DUMP_GRANT(D_CACHE, cli,
+                              "no grant space, fall back to sync i/o\n");
+               break;
+       default:
+               CDEBUG(D_CACHE, "%s: event for cache space @ %p never arrived due to %d, fall back to sync i/o\n",
+                      cli->cl_import->imp_obd->obd_name, &ocw, rc);
+               break;
+       }
 out:
        spin_unlock(&cli->cl_loi_list_lock);
-       OSC_DUMP_GRANT(D_CACHE, cli, "returned %d.\n", rc);
        return rc;
 }
 
@@ -1679,10 +1700,8 @@ void osc_wake_cache_waiters(struct client_obd *cli)
                        goto wakeup;
                }
 
-               ocw->ocw_rc = 0;
-               if (!osc_enter_cache_try(cli, ocw->ocw_oap, ocw->ocw_grant, 0))
-                       ocw->ocw_rc = -EDQUOT;
-
+               if (osc_enter_cache_try(cli, ocw->ocw_oap, ocw->ocw_grant, 0))
+                       ocw->ocw_rc = 0;
 wakeup:
                CDEBUG(D_CACHE, "wake up %p for oap %p, avail grant %ld, %d\n",
                       ocw, ocw->ocw_oap, cli->cl_avail_grant, ocw->ocw_rc);