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[fs/lustre-release.git] / lustre / ldlm / ldlm_extent.c
index 7d9e1bf..f1f88ce 100644 (file)
 
 #include "ldlm_internal.h"
 
+#define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
+
+/* fixup the ldlm_extent after expanding */
+static void ldlm_extent_internal_policy_fixup(struct ldlm_lock *req,
+                                              struct ldlm_extent *new_ex,
+                                              int conflicting)
+{
+        ldlm_mode_t req_mode = req->l_req_mode;
+        __u64 req_start = req->l_req_extent.start;
+        __u64 req_end = req->l_req_extent.end;
+        __u64 req_align, mask;
+        if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) {
+                if (req_end < req_start + LDLM_MAX_GROWN_EXTENT)
+                        new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT,
+                                          new_ex->end);
+        }
+
+        if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) {
+                EXIT;
+                return;
+        }
+
+        /* we need to ensure that the lock extent is properly aligned to what
+         * the client requested.  We align it to the lowest-common denominator
+         * of the clients requested lock start and end alignment. */
+        mask = 0x1000ULL;
+        req_align = (req_end + 1) | req_start;
+        if (req_align != 0) {
+                while ((req_align & mask) == 0)
+                        mask <<= 1;
+        }
+        mask -= 1;
+        /* We can only shrink the lock, not grow it.
+         * This should never cause lock to be smaller than requested,
+         * since requested lock was already aligned on these boundaries. */
+        new_ex->start = ((new_ex->start - 1) | mask) + 1;
+        new_ex->end = ((new_ex->end + 1) & ~mask) - 1;
+        LASSERTF(new_ex->start <= req_start,
+                 "mask "LPX64" grant start "LPU64" req start "LPU64"\n",
+                 mask, new_ex->start, req_start);
+        LASSERTF(new_ex->end >= req_end,
+                 "mask "LPX64" grant end "LPU64" req end "LPU64"\n",
+                 mask, new_ex->end, req_end);
+}
+
+/* The purpose of this function is to return:
+ * - the maximum extent
+ * - containing the requested extent
+ * - and not overlapping existing conflicting extents outside the requested one
+ *
+ * Use interval tree to expand the lock extent for granted lock.
+ */
+static void ldlm_extent_internal_policy_granted(struct ldlm_lock *req,
+                                                struct ldlm_extent *new_ex)
+{
+        struct ldlm_resource *res = req->l_resource;
+        ldlm_mode_t req_mode = req->l_req_mode;
+        __u64 req_start = req->l_req_extent.start;
+        __u64 req_end = req->l_req_extent.end;
+        struct ldlm_interval_tree *tree;
+        struct interval_node_extent limiter = { new_ex->start, new_ex->end };
+        int conflicting = 0;
+        int idx;
+        ENTRY;
+
+        lockmode_verify(req_mode);
+
+        /* using interval tree to handle the ldlm extent granted locks */
+        for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+                struct interval_node_extent ext = { req_start, req_end };
+
+                tree = &res->lr_itree[idx];
+                if (lockmode_compat(tree->lit_mode, req_mode))
+                        continue;
+
+                conflicting += tree->lit_size;
+                if (conflicting > 4)
+                        limiter.start = req_start;
+
+                if (interval_is_overlapped(tree->lit_root, &ext))
+                        printk("req_mode = %d, tree->lit_mode = %d, tree->lit_size = %d\n",
+                               req_mode, tree->lit_mode, tree->lit_size);
+                interval_expand(tree->lit_root, &ext, &limiter);
+                limiter.start = max(limiter.start, ext.start);
+                limiter.end = min(limiter.end, ext.end);
+                if (limiter.start == req_start && limiter.end == req_end)
+                        break;
+        }
+
+        new_ex->start = limiter.start;
+        new_ex->end = limiter.end;
+        LASSERT(new_ex->start <= req_start);
+        LASSERT(new_ex->end >= req_end);
+
+        ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
+        EXIT;
+}
+
 /* The purpose of this function is to return:
  * - the maximum extent
  * - containing the requested extent
  * - and not overlapping existing conflicting extents outside the requested one
  */
 static void
-ldlm_extent_internal_policy(struct list_head *queue, struct ldlm_lock *req,
-                            struct ldlm_extent *new_ex)
+ldlm_extent_internal_policy_waiting(struct ldlm_lock *req,
+                                    struct ldlm_extent *new_ex)
 {
         struct list_head *tmp;
+        struct ldlm_resource *res = req->l_resource;
         ldlm_mode_t req_mode = req->l_req_mode;
         __u64 req_start = req->l_req_extent.start;
         __u64 req_end = req->l_req_extent.end;
-        __u64 req_align, mask;
         int conflicting = 0;
         ENTRY;
 
         lockmode_verify(req_mode);
 
-        list_for_each(tmp, queue) {
+        /* for waiting locks */
+        list_for_each(tmp, &res->lr_waiting) {
                 struct ldlm_lock *lock;
                 struct ldlm_extent *l_extent;
 
@@ -85,16 +185,14 @@ ldlm_extent_internal_policy(struct list_head *queue, struct ldlm_lock *req,
                         new_ex->start = req_start;
 
                 /* If lock doesn't overlap new_ex, skip it. */
-                if (l_extent->end < new_ex->start ||
-                    l_extent->start > new_ex->end)
+                if (!ldlm_extent_overlap(l_extent, new_ex))
                         continue;
 
                 /* Locks conflicting in requested extents and we can't satisfy
                  * both locks, so ignore it.  Either we will ping-pong this
                  * extent (we would regardless of what extent we granted) or
                  * lock is unused and it shouldn't limit our extent growth. */
-                if (lock->l_req_extent.end >= req_start &&
-                    lock->l_req_extent.start <= req_end)
+                if (ldlm_extent_overlap(&lock->l_req_extent,&req->l_req_extent))
                         continue;
 
                 /* We grow extents downwards only as far as they don't overlap
@@ -123,43 +221,11 @@ ldlm_extent_internal_policy(struct list_head *queue, struct ldlm_lock *req,
                 }
         }
 
-#define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
-        if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) {
-                if (req_end < req_start + LDLM_MAX_GROWN_EXTENT)
-                        new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT,
-                                          new_ex->end);
-        }
-
-        if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) {
-                EXIT;
-                return;
-        }
-
-        /* we need to ensure that the lock extent is properly aligned to what
-         * the client requested.  We align it to the lowest-common denominator
-         * of the clients requested lock start and end alignment. */
-        mask = 0x1000ULL;
-        req_align = (req_end + 1) | req_start;
-        if (req_align != 0) {
-                while ((req_align & mask) == 0)
-                        mask <<= 1;
-        }
-        mask -= 1;
-        /* We can only shrink the lock, not grow it.
-         * This should never cause lock to be smaller than requested,
-         * since requested lock was already aligned on these boundaries. */
-        new_ex->start = ((new_ex->start - 1) | mask) + 1;
-        new_ex->end = ((new_ex->end + 1) & ~mask) - 1;
-        LASSERTF(new_ex->start <= req_start,
-                 "mask "LPX64" grant start "LPU64" req start "LPU64"\n",
-                 mask, new_ex->start, req_start);
-        LASSERTF(new_ex->end >= req_end,
-                 "mask "LPX64" grant end "LPU64" req end "LPU64"\n",
-                 mask, new_ex->end, req_end);
-
+        ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
         EXIT;
 }
 
+
 /* In order to determine the largest possible extent we can grant, we need
  * to scan all of the queues. */
 static void ldlm_extent_policy(struct ldlm_resource *res,
@@ -182,8 +248,8 @@ static void ldlm_extent_policy(struct ldlm_resource *res,
                 /* fast-path whole file locks */
                 return;
 
-        ldlm_extent_internal_policy(&res->lr_granted, lock, &new_ex);
-        ldlm_extent_internal_policy(&res->lr_waiting, lock, &new_ex);
+        ldlm_extent_internal_policy_granted(lock, &new_ex);
+        ldlm_extent_internal_policy_waiting(lock, &new_ex);
 
         if (new_ex.start != lock->l_policy_data.l_extent.start ||
             new_ex.end != lock->l_policy_data.l_extent.end) {
@@ -193,6 +259,42 @@ static void ldlm_extent_policy(struct ldlm_resource *res,
         }
 }
 
+struct ldlm_extent_compat_args {
+        struct list_head *work_list;
+        struct ldlm_lock *lock;
+        ldlm_mode_t mode;
+        int *compat;
+};
+
+static enum interval_iter ldlm_extent_compat_cb(struct interval_node *n,
+                                                void *data)
+{
+        struct ldlm_extent_compat_args *priv = data;
+        struct ldlm_interval *node = to_ldlm_interval(n);
+        struct list_head *work_list = priv->work_list;
+        struct ldlm_lock *lock, *enq = priv->lock;
+        ldlm_mode_t mode = priv->mode;
+        ENTRY;
+
+        LASSERT(!list_empty(&node->li_group));
+
+        list_for_each_entry(lock, &node->li_group, l_sl_policy) {
+                /* interval tree is for granted lock */
+                LASSERTF(mode == lock->l_granted_mode,
+                         "mode = %s, lock->l_granted_mode = %s\n",
+                         ldlm_lockname[mode],
+                         ldlm_lockname[lock->l_granted_mode]);
+
+                if (lock->l_blocking_ast)
+                        ldlm_add_ast_work_item(lock, enq, work_list);
+        }
+
+        if (priv->compat)
+                *priv->compat = 0;
+
+        RETURN(INTERVAL_ITER_CONT);
+}
+
 /* Determine if the lock is compatible with all locks on the queue.
  * We stop walking the queue if we hit ourselves so we don't take
  * conflicting locks enqueued after us into accound, or we'd wait forever.
@@ -209,6 +311,7 @@ ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 {
         struct list_head *tmp;
         struct ldlm_lock *lock;
+        struct ldlm_resource *res = req->l_resource;
         ldlm_mode_t req_mode = req->l_req_mode;
         __u64 req_start = req->l_req_extent.start;
         __u64 req_end = req->l_req_extent.end;
@@ -218,6 +321,71 @@ ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
         lockmode_verify(req_mode);
 
+        /* Using interval tree for granted lock */
+        if (queue == &res->lr_granted) {
+                struct ldlm_interval_tree *tree;
+                struct ldlm_extent_compat_args data = {.work_list = work_list,
+                                               .lock = req,
+                                               .compat = &compat };
+                struct interval_node_extent ex = { .start = req_start,
+                                                   .end = req_end };
+                int idx, rc;
+
+                for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+                        tree = &res->lr_itree[idx];
+                        if (tree->lit_root == NULL) /* empty tree, skipped */
+                                continue;
+
+                        data.mode = tree->lit_mode;
+                        if (lockmode_compat(req_mode, tree->lit_mode)) {
+                                struct ldlm_interval *node;
+                                struct ldlm_extent *extent;
+
+                                if (req_mode != LCK_GROUP)
+                                        continue;
+
+                                /* group lock, grant it immediately if
+                                 * compatible */
+                                node = to_ldlm_interval(tree->lit_root);
+                                extent = ldlm_interval_extent(node);
+                                if (req->l_policy_data.l_extent.gid ==
+                                    extent->gid)
+                                        RETURN(2);
+                        }
+
+                        if (tree->lit_mode == LCK_GROUP) {
+                                if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+                                        compat = -EWOULDBLOCK;
+                                        goto destroylock;
+                                }
+
+                                *flags |= LDLM_FL_NO_TIMEOUT;
+                                if (!work_list)
+                                        RETURN(0);
+
+                                /* if work list is not NULL,add all
+                                   locks in the tree to work list */
+                                compat = 0;
+                                interval_iterate(tree->lit_root,
+                                                 ldlm_extent_compat_cb, &data);
+                                continue;
+                        }
+
+                        if (!work_list) {
+                                rc = interval_is_overlapped(tree->lit_root,&ex);
+                                if (rc)
+                                        RETURN(0);
+                        } else {
+                                interval_search(tree->lit_root, &ex,
+                                                ldlm_extent_compat_cb, &data);
+                                if (!list_empty(work_list) && compat)
+                                        compat = 0;
+                        }
+                }
+                RETURN(compat);
+        }
+
+        /* for waiting queue */
         list_for_each(tmp, queue) {
                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 
@@ -251,6 +419,34 @@ ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
                 /* locks are compatible, overlap doesn't matter */
                 if (lockmode_compat(lock->l_req_mode, req_mode)) {
+                        if (req_mode == LCK_PR &&
+                            ((lock->l_policy_data.l_extent.start <=
+                             req->l_policy_data.l_extent.start) &&
+                             (lock->l_policy_data.l_extent.end >=
+                              req->l_policy_data.l_extent.end))) {
+                                /* If we met a PR lock just like us or wider,
+                                   and nobody down the list conflicted with
+                                   it, that means we can skip processing of
+                                   the rest of the list and safely place
+                                   ourselves at the end of the list, or grant
+                                   (dependent if we met an conflicting locks
+                                   before in the list).
+                                   In case of 1st enqueue only we continue
+                                   traversing if there is something conflicting
+                                   down the list because we need to make sure
+                                   that something is marked as AST_SENT as well,
+                                   in cse of empy worklist we would exit on
+                                   first conflict met. */
+                                /* There IS a case where such flag is
+                                   not set for a lock, yet it blocks
+                                   something. Luckily for us this is
+                                   only during destroy, so lock is
+                                   exclusive. So here we are safe */
+                                if (!(lock->l_flags & LDLM_FL_AST_SENT)) {
+                                        RETURN(compat);
+                                }
+                        }
+
                         /* non-group locks are compatible, overlap doesn't
                            matter */
                         if (likely(req_mode != LCK_GROUP))
@@ -382,7 +578,8 @@ int ldlm_process_extent_lock(struct ldlm_lock *lock, int *flags, int first_enq,
 
                 ldlm_resource_unlink_lock(lock);
 
-                ldlm_extent_policy(res, lock, flags);
+                if (!OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_EVICT_RACE))
+                        ldlm_extent_policy(res, lock, flags);
                 ldlm_grant_lock(lock, work_list);
                 RETURN(LDLM_ITER_CONTINUE);
         }
@@ -413,10 +610,26 @@ int ldlm_process_extent_lock(struct ldlm_lock *lock, int *flags, int first_enq,
                 if (list_empty(&lock->l_res_link))
                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
                 unlock_res(res);
-                rc = ldlm_run_bl_ast_work(&rpc_list);
+                rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_BL_AST);
                 lock_res(res);
-                if (rc == -ERESTART)
+
+                if (rc == -ERESTART) {
+                        /* lock was granted while resource was unlocked. */
+                        if (lock->l_granted_mode == lock->l_req_mode) {
+                                /* bug 11300: if the lock has been granted,
+                                 * break earlier because otherwise, we will go
+                                 * to restart and ldlm_resource_unlink will be
+                                 * called and it causes the interval node to be
+                                 * freed. Then we will fail at 
+                                 * ldlm_extent_add_lock() */
+                                *flags &= ~(LDLM_FL_BLOCK_GRANTED | LDLM_FL_BLOCK_CONV |
+                                            LDLM_FL_BLOCK_WAIT);
+                                GOTO(out, rc = 0);
+                        }
+
                         GOTO(restart, -ERESTART);
+                }
+
                 *flags |= LDLM_FL_BLOCK_GRANTED;
                 /* this way we force client to wait for the lock
                  * endlessly once the lock is enqueued -bzzz */
@@ -464,3 +677,124 @@ __u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms)
 
         RETURN(kms);
 }
+
+cfs_mem_cache_t *ldlm_interval_slab;
+struct ldlm_interval *ldlm_interval_alloc(struct ldlm_lock *lock)
+{
+        struct ldlm_interval *node;
+        ENTRY;
+
+        LASSERT(lock->l_resource->lr_type == LDLM_EXTENT);
+        OBD_SLAB_ALLOC(node, ldlm_interval_slab, CFS_ALLOC_IO, sizeof(*node));
+        if (node == NULL)
+                RETURN(NULL);
+
+        CFS_INIT_LIST_HEAD(&node->li_group);
+        ldlm_interval_attach(node, lock);
+        RETURN(node);
+}
+
+void ldlm_interval_free(struct ldlm_interval *node)
+{
+        if (node) {
+                LASSERT(list_empty(&node->li_group));
+                OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
+        }
+}
+
+/* interval tree, for LDLM_EXTENT. */
+void ldlm_interval_attach(struct ldlm_interval *n,
+                          struct ldlm_lock *l)
+{
+        LASSERT(l->l_tree_node == NULL);
+        LASSERT(l->l_resource->lr_type == LDLM_EXTENT);
+
+        list_add_tail(&l->l_sl_policy, &n->li_group);
+        l->l_tree_node = n;
+}
+
+struct ldlm_interval *ldlm_interval_detach(struct ldlm_lock *l)
+{
+        struct ldlm_interval *n = l->l_tree_node;
+
+        if (n == NULL)
+                return NULL;
+
+        LASSERT(!list_empty(&n->li_group));
+        l->l_tree_node = NULL;
+        list_del_init(&l->l_sl_policy);
+
+        return (list_empty(&n->li_group) ? n : NULL);
+}
+
+static inline int lock_mode_to_index(ldlm_mode_t mode)
+{
+        int index;
+
+        LASSERT(mode != 0);
+        LASSERT(IS_PO2(mode));
+        for (index = -1; mode; index++, mode >>= 1) ;
+        LASSERT(index < LCK_MODE_NUM);
+        return index;
+}
+
+void ldlm_extent_add_lock(struct ldlm_resource *res,
+                          struct ldlm_lock *lock)
+{
+        struct interval_node *found, **root;
+        struct ldlm_interval *node;
+        struct ldlm_extent *extent;
+        int idx;
+
+        LASSERT(lock->l_granted_mode == lock->l_req_mode);
+
+        node = lock->l_tree_node;
+        LASSERT(node != NULL);
+
+        idx = lock_mode_to_index(lock->l_granted_mode);
+        LASSERT(lock->l_granted_mode == 1 << idx);
+        LASSERT(lock->l_granted_mode == res->lr_itree[idx].lit_mode);
+
+        /* node extent initialize */
+        extent = &lock->l_policy_data.l_extent;
+        interval_set(&node->li_node, extent->start, extent->end);
+
+        root = &res->lr_itree[idx].lit_root;
+        found = interval_insert(&node->li_node, root);
+        if (found) { /* The policy group found. */
+                struct ldlm_interval *tmp = ldlm_interval_detach(lock);
+                LASSERT(tmp != NULL);
+                ldlm_interval_free(tmp);
+                ldlm_interval_attach(to_ldlm_interval(found), lock);
+        }
+        res->lr_itree[idx].lit_size++;
+
+        /* even though we use interval tree to manage the extent lock, we also
+         * add the locks into grant list, for debug purpose, .. */
+        ldlm_resource_add_lock(res, &res->lr_granted, lock);
+}
+
+void ldlm_extent_unlink_lock(struct ldlm_lock *lock)
+{
+        struct ldlm_resource *res = lock->l_resource;
+        struct ldlm_interval *node;
+        struct ldlm_interval_tree *tree;
+        int idx;
+
+        if (lock->l_granted_mode != lock->l_req_mode)
+                return;
+
+        LASSERT(lock->l_tree_node != NULL);
+        idx = lock_mode_to_index(lock->l_granted_mode);
+        LASSERT(lock->l_granted_mode == 1 << idx);
+        tree = &res->lr_itree[idx];
+
+        LASSERT(tree->lit_root != NULL); /* assure the tree is not null */
+
+        tree->lit_size--;
+        node = ldlm_interval_detach(lock);
+        if (node) {
+                interval_erase(&node->li_node, &tree->lit_root);
+                ldlm_interval_free(node);
+        }
+}