LU-14543 target: prevent overflowing of tgd->tgd_tot_granted

[fs/lustre-release.git] / lustre / target / tgt_grant.c

diff --git a/lustre/target/tgt_grant.c b/lustre/target/tgt_grant.c
index 72416e0..2e1df78 100644 (file)
--- a/lustre/target/tgt_grant.c
+++ b/lustre/target/tgt_grant.c
@@ -884,6 +884,7 @@ static void tgt_grant_check(const struct lu_env *env, struct obd_export *exp,
  *                             have
  * \param[in] left             remaining free space with granted space taken
  *                             out
+ * \param[in] chunk            grant allocation unit
  * \param[in] conservative     if set to true, the server should be cautious
  *                             and limit how much space is granted back to the
  *                             client. Otherwise, the server should try hard to
@@ -964,12 +965,13 @@ static long tgt_grant_alloc(struct obd_export *exp, u64 curgrant,
        tgd->tgd_tot_granted += grant;
        ted->ted_grant += grant;
 
-       if (ted->ted_grant < 0) {
+       if (unlikely(ted->ted_grant < 0 || ted->ted_grant > want + chunk)) {
                CERROR("%s: cli %s/%p grant %ld want %llu current %llu\n",
                       obd->obd_name, exp->exp_client_uuid.uuid, exp,
                       ted->ted_grant, want, curgrant);
                spin_unlock(&tgd->tgd_grant_lock);
-               LBUG();
+               if (tgd->tgd_lbug_on_grant_miscount)
+                       LBUG();
        }
 
        CDEBUG(D_CACHE,
@@ -1092,13 +1094,35 @@ void tgt_grant_discard(struct obd_export *exp)
 
        tgd = &lut->lut_tgd;
        spin_lock(&tgd->tgd_grant_lock);
-       if (tgd->tgd_tot_granted < ted->ted_grant) {
-               CERROR("%s: tot_granted %llu < cli %s/%p ted_grant %ld\n",
-                      obd->obd_name, tgd->tgd_tot_granted,
-                      exp->exp_client_uuid.uuid, exp, ted->ted_grant);
+       if (unlikely(tgd->tgd_tot_granted < ted->ted_grant ||
+                    tgd->tgd_tot_dirty < ted->ted_dirty)) {
+               struct obd_export *e;
+               u64 ttg = 0;
+               u64 ttd = 0;
+
+               list_for_each_entry(e, &obd->obd_exports, exp_obd_chain) {
+                       LASSERT(exp != e);
+                       ttg += e->exp_target_data.ted_grant;
+                       ttg += e->exp_target_data.ted_pending;
+                       ttd += e->exp_target_data.ted_dirty;
+               }
+               if (tgd->tgd_tot_granted < ted->ted_grant)
+                       CERROR("%s: cli %s/%p: tot_granted %llu < ted_grant %ld, corrected to %llu",
+                              obd->obd_name,  exp->exp_client_uuid.uuid, exp,
+                              tgd->tgd_tot_granted, ted->ted_grant, ttg);
+               if (tgd->tgd_tot_dirty < ted->ted_dirty)
+                       CERROR("%s: cli %s/%p: tot_dirty %llu < ted_dirty %ld, corrected to %llu",
+                              obd->obd_name, exp->exp_client_uuid.uuid, exp,
+                              tgd->tgd_tot_dirty, ted->ted_dirty, ttd);
+               tgd->tgd_tot_granted = ttg;
+               tgd->tgd_tot_dirty = ttd;
+       } else {
+               tgd->tgd_tot_granted -= ted->ted_grant;
+               tgd->tgd_tot_dirty -= ted->ted_dirty;
        }
-       tgd->tgd_tot_granted -= ted->ted_grant;
        ted->ted_grant = 0;
+       ted->ted_dirty = 0;
+
        if (tgd->tgd_tot_pending < ted->ted_pending) {
                CERROR("%s: tot_pending %llu < cli %s/%p ted_pending %ld\n",
                       obd->obd_name, tgd->tgd_tot_pending,
@@ -1106,13 +1130,6 @@ void tgt_grant_discard(struct obd_export *exp)
        }
        /* tgd_tot_pending is handled in tgt_grant_commit as bulk
         * commmits */
-       if (tgd->tgd_tot_dirty < ted->ted_dirty) {
-               CERROR("%s: tot_dirty %llu < cli %s/%p ted_dirty %ld\n",
-                      obd->obd_name, tgd->tgd_tot_dirty,
-                      exp->exp_client_uuid.uuid, exp, ted->ted_dirty);
-       }
-       tgd->tgd_tot_dirty -= ted->ted_dirty;
-       ted->ted_dirty = 0;
        spin_unlock(&tgd->tgd_grant_lock);
 }
 EXPORT_SYMBOL(tgt_grant_discard);
@@ -1675,3 +1692,60 @@ ssize_t grant_compat_disable_store(struct kobject *kobj,
        return count;
 }
 EXPORT_SYMBOL(grant_compat_disable_store);
+
+/**
+ * Show lbug_on_grant_miscount mode.
+ *
+ * @kobj               kobject embedded in obd_device
+ * @attr               unused
+ * @buf                        buf used by sysfs to print out data
+ *
+ * Return:             string length of @buf output on success
+ */
+ssize_t lbug_on_grant_miscount_show(struct kobject *kobj,
+                                   struct attribute *attr, char *buf)
+{
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct tg_grants_data *tgd = &obd->u.obt.obt_lut->lut_tgd;
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n",
+                        tgd->tgd_lbug_on_grant_miscount);
+}
+EXPORT_SYMBOL(lbug_on_grant_miscount_show);
+
+/**
+ * Change lbug on grant miscount mode.
+ *
+ * Setting tgd_lbug_on_grant_miscount to 1 makes tgt_alloc_grant() to
+ * LBUG on apparently wrong ted->ted_grant
+ *
+ * @kobj       kobject embedded in obd_device
+ * @attr       unused
+ * @buffer     string which represents mode
+ *             1: use LBUG on grant miscount
+ *             0: use CERROR on grant miscount
+ * @count      @buffer length
+ *
+ * Return:     @count on success
+ *             negative number on error
+ */
+ssize_t lbug_on_grant_miscount_store(struct kobject *kobj,
+                                    struct attribute *attr,
+                                    const char *buffer, size_t count)
+{
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct tg_grants_data *tgd = &obd->u.obt.obt_lut->lut_tgd;
+       bool val;
+       int rc;
+
+       rc = kstrtobool(buffer, &val);
+       if (rc)
+               return rc;
+
+       tgd->tgd_lbug_on_grant_miscount = val;
+
+       return count;
+}
+EXPORT_SYMBOL(lbug_on_grant_miscount_store);