diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ldlm/ldlm_extent.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/ldlm/ldlm_extent.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c b/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c new file mode 100644 index 000000000000..f7432f78e396 --- /dev/null +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c @@ -0,0 +1,242 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2010, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * lustre/ldlm/ldlm_extent.c + * + * Author: Peter Braam <braam@clusterfs.com> + * Author: Phil Schwan <phil@clusterfs.com> + */ + +/** + * This file contains implementation of EXTENT lock type + * + * EXTENT lock type is for locking a contiguous range of values, represented + * by 64-bit starting and ending offsets (inclusive). There are several extent + * lock modes, some of which may be mutually incompatible. Extent locks are + * considered incompatible if their modes are incompatible and their extents + * intersect. See the lock mode compatibility matrix in lustre_dlm.h. + */ + +#define DEBUG_SUBSYSTEM S_LDLM +# include <linux/libcfs/libcfs.h> + +#include <lustre_dlm.h> +#include <obd_support.h> +#include <obd.h> +#include <obd_class.h> +#include <lustre_lib.h> + +#include "ldlm_internal.h" + + +/* When a lock is cancelled by a client, the KMS may undergo change if this + * is the "highest lock". This function returns the new KMS value. + * Caller must hold lr_lock already. + * + * NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */ +__u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms) +{ + struct ldlm_resource *res = lock->l_resource; + struct list_head *tmp; + struct ldlm_lock *lck; + __u64 kms = 0; + ENTRY; + + /* don't let another thread in ldlm_extent_shift_kms race in + * just after we finish and take our lock into account in its + * calculation of the kms */ + lock->l_flags |= LDLM_FL_KMS_IGNORE; + + list_for_each(tmp, &res->lr_granted) { + lck = list_entry(tmp, struct ldlm_lock, l_res_link); + + if (lck->l_flags & LDLM_FL_KMS_IGNORE) + continue; + + if (lck->l_policy_data.l_extent.end >= old_kms) + RETURN(old_kms); + + /* This extent _has_ to be smaller than old_kms (checked above) + * so kms can only ever be smaller or the same as old_kms. */ + if (lck->l_policy_data.l_extent.end + 1 > kms) + kms = lck->l_policy_data.l_extent.end + 1; + } + LASSERTF(kms <= old_kms, "kms "LPU64" old_kms "LPU64"\n", kms, old_kms); + + RETURN(kms); +} +EXPORT_SYMBOL(ldlm_extent_shift_kms); + +struct kmem_cache *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_PTR_GFP(node, ldlm_interval_slab, __GFP_IO); + if (node == NULL) + RETURN(NULL); + + 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)); + LASSERT(!interval_is_intree(&node->li_node)); + 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; +} + +/** Add newly granted lock into interval tree for the resource. */ +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); + LASSERT(!interval_is_intree(&node->li_node)); + + 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); +} + +/** Remove cancelled lock from resource interval tree. */ +void ldlm_extent_unlink_lock(struct ldlm_lock *lock) +{ + struct ldlm_resource *res = lock->l_resource; + struct ldlm_interval *node = lock->l_tree_node; + struct ldlm_interval_tree *tree; + int idx; + + if (!node || !interval_is_intree(&node->li_node)) /* duplicate unlink */ + return; + + 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); + } +} + +void ldlm_extent_policy_wire_to_local(const ldlm_wire_policy_data_t *wpolicy, + ldlm_policy_data_t *lpolicy) +{ + memset(lpolicy, 0, sizeof(*lpolicy)); + lpolicy->l_extent.start = wpolicy->l_extent.start; + lpolicy->l_extent.end = wpolicy->l_extent.end; + lpolicy->l_extent.gid = wpolicy->l_extent.gid; +} + +void ldlm_extent_policy_local_to_wire(const ldlm_policy_data_t *lpolicy, + ldlm_wire_policy_data_t *wpolicy) +{ + memset(wpolicy, 0, sizeof(*wpolicy)); + wpolicy->l_extent.start = lpolicy->l_extent.start; + wpolicy->l_extent.end = lpolicy->l_extent.end; + wpolicy->l_extent.gid = lpolicy->l_extent.gid; +} |