staging: add Lustre file system client support

Lustre is the most deployed distributed file system
in the HPC (High Performance Computing) world. The patch
adds its client side support.

The code is not very clean and needs to live in drivers/staging
for some time for continuing cleanup work. See
drivers/staging/lustre/TODO for details.

The code is based on Lustre master commit faefbfc04

commit faefbfc0460bc00f2ee4c1c1c86aa1e39b9eea49
Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Date:   Tue Apr 30 23:05:21 2013 +0400

    LU-3244 utils: tunefs.lustre should preserve virgin label

Plus a few under-review patches on Whamcloud gerrit:
3.8 kernel support:
http://review.whamcloud.com/#change,5973
http://review.whamcloud.com/#change,5974
http://review.whamcloud.com/#change,5768
http://review.whamcloud.com/#change,5781
http://review.whamcloud.com/#change,5763
http://review.whamcloud.com/#change,5613
http://review.whamcloud.com/#change,5655

3.9 kernel support:
http://review.whamcloud.com/#change,5898
http://review.whamcloud.com/#change,5899

Kconfig/Kbuild:
http://review.whamcloud.com/#change,4646
http://review.whamcloud.com/#change,4644

libcfs cleanup:
http://review.whamcloud.com/#change,2831
http://review.whamcloud.com/#change,4775
http://review.whamcloud.com/#change,4776
http://review.whamcloud.com/#change,4777
http://review.whamcloud.com/#change,4778
http://review.whamcloud.com/#change,4779
http://review.whamcloud.com/#change,4780

All starting/trailing whitespaces are removed, to match kernel
coding style. Also ran scripts/cleanfile on all lustre source files.

[maked the Kconfig depend on BROKEN as the recent procfs changes causes
this to fail - gregkh]

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 0000000..f7432f7
--- /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;
+}