Initial import

5 files changed, 1440 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/fld/Makefile b/drivers/staging/lustre/lustre/fld/Makefile
new file mode 100644
index 000000000..2bbf08433
--- /dev/null
+++ b/drivers/staging/lustre/lustre/fld/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_LUSTRE_FS) += fld.o
+fld-y := fld_request.o fld_cache.o
+fld-$(CONFIG_PROC_FS) += lproc_fld.o
diff --git a/drivers/staging/lustre/lustre/fld/fld_cache.c b/drivers/staging/lustre/lustre/fld/fld_cache.c
new file mode 100644
index 000000000..0d0a73745
--- /dev/null
+++ b/drivers/staging/lustre/lustre/fld/fld_cache.c
@@ -0,0 +1,546 @@
+/*
+ * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, 2013, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/fld/fld_cache.c
+ *
+ * FLD (Fids Location Database)
+ *
+ * Author: Pravin Shelar <pravin.shelar@sun.com>
+ * Author: Yury Umanets <umka@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_FLD
+
+#include "../../include/linux/libcfs/libcfs.h"
+#include <linux/module.h>
+#include <asm/div64.h>
+
+#include "../include/obd.h"
+#include "../include/obd_class.h"
+#include "../include/lustre_ver.h"
+#include "../include/obd_support.h"
+#include "../include/lprocfs_status.h"
+
+#include "../include/dt_object.h"
+#include "../include/lustre_req_layout.h"
+#include "../include/lustre_fld.h"
+#include "fld_internal.h"
+
+/**
+ * create fld cache.
+ */
+struct fld_cache *fld_cache_init(const char *name,
+				 int cache_size, int cache_threshold)
+{
+	struct fld_cache *cache;
+
+	LASSERT(name != NULL);
+	LASSERT(cache_threshold < cache_size);
+
+	OBD_ALLOC_PTR(cache);
+	if (cache == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&cache->fci_entries_head);
+	INIT_LIST_HEAD(&cache->fci_lru);
+
+	cache->fci_cache_count = 0;
+	rwlock_init(&cache->fci_lock);
+
+	strlcpy(cache->fci_name, name,
+		sizeof(cache->fci_name));
+
+	cache->fci_cache_size = cache_size;
+	cache->fci_threshold = cache_threshold;
+
+	/* Init fld cache info. */
+	memset(&cache->fci_stat, 0, sizeof(cache->fci_stat));
+
+	CDEBUG(D_INFO, "%s: FLD cache - Size: %d, Threshold: %d\n",
+	       cache->fci_name, cache_size, cache_threshold);
+
+	return cache;
+}
+
+/**
+ * destroy fld cache.
+ */
+void fld_cache_fini(struct fld_cache *cache)
+{
+	__u64 pct;
+
+	LASSERT(cache != NULL);
+	fld_cache_flush(cache);
+
+	if (cache->fci_stat.fst_count > 0) {
+		pct = cache->fci_stat.fst_cache * 100;
+		do_div(pct, cache->fci_stat.fst_count);
+	} else {
+		pct = 0;
+	}
+
+	CDEBUG(D_INFO, "FLD cache statistics (%s):\n", cache->fci_name);
+	CDEBUG(D_INFO, "  Total reqs: %llu\n", cache->fci_stat.fst_count);
+	CDEBUG(D_INFO, "  Cache reqs: %llu\n", cache->fci_stat.fst_cache);
+	CDEBUG(D_INFO, "  Cache hits: %llu%%\n", pct);
+
+	OBD_FREE_PTR(cache);
+}
+
+/**
+ * delete given node from list.
+ */
+void fld_cache_entry_delete(struct fld_cache *cache,
+			    struct fld_cache_entry *node)
+{
+	list_del(&node->fce_list);
+	list_del(&node->fce_lru);
+	cache->fci_cache_count--;
+	OBD_FREE_PTR(node);
+}
+
+/**
+ * fix list by checking new entry with NEXT entry in order.
+ */
+static void fld_fix_new_list(struct fld_cache *cache)
+{
+	struct fld_cache_entry *f_curr;
+	struct fld_cache_entry *f_next;
+	struct lu_seq_range *c_range;
+	struct lu_seq_range *n_range;
+	struct list_head *head = &cache->fci_entries_head;
+
+restart_fixup:
+
+	list_for_each_entry_safe(f_curr, f_next, head, fce_list) {
+		c_range = &f_curr->fce_range;
+		n_range = &f_next->fce_range;
+
+		LASSERT(range_is_sane(c_range));
+		if (&f_next->fce_list == head)
+			break;
+
+		if (c_range->lsr_flags != n_range->lsr_flags)
+			continue;
+
+		LASSERTF(c_range->lsr_start <= n_range->lsr_start,
+			 "cur lsr_start "DRANGE" next lsr_start "DRANGE"\n",
+			 PRANGE(c_range), PRANGE(n_range));
+
+		/* check merge possibility with next range */
+		if (c_range->lsr_end == n_range->lsr_start) {
+			if (c_range->lsr_index != n_range->lsr_index)
+				continue;
+			n_range->lsr_start = c_range->lsr_start;
+			fld_cache_entry_delete(cache, f_curr);
+			continue;
+		}
+
+		/* check if current range overlaps with next range. */
+		if (n_range->lsr_start < c_range->lsr_end) {
+			if (c_range->lsr_index == n_range->lsr_index) {
+				n_range->lsr_start = c_range->lsr_start;
+				n_range->lsr_end = max(c_range->lsr_end,
+						       n_range->lsr_end);
+				fld_cache_entry_delete(cache, f_curr);
+			} else {
+				if (n_range->lsr_end <= c_range->lsr_end) {
+					*n_range = *c_range;
+					fld_cache_entry_delete(cache, f_curr);
+				} else
+					n_range->lsr_start = c_range->lsr_end;
+			}
+
+			/* we could have overlap over next
+			 * range too. better restart. */
+			goto restart_fixup;
+		}
+
+		/* kill duplicates */
+		if (c_range->lsr_start == n_range->lsr_start &&
+		    c_range->lsr_end == n_range->lsr_end)
+			fld_cache_entry_delete(cache, f_curr);
+	}
+}
+
+/**
+ * add node to fld cache
+ */
+static inline void fld_cache_entry_add(struct fld_cache *cache,
+				       struct fld_cache_entry *f_new,
+				       struct list_head *pos)
+{
+	list_add(&f_new->fce_list, pos);
+	list_add(&f_new->fce_lru, &cache->fci_lru);
+
+	cache->fci_cache_count++;
+	fld_fix_new_list(cache);
+}
+
+/**
+ * Check if cache needs to be shrunk. If so - do it.
+ * Remove one entry in list and so on until cache is shrunk enough.
+ */
+static int fld_cache_shrink(struct fld_cache *cache)
+{
+	struct fld_cache_entry *flde;
+	struct list_head *curr;
+	int num = 0;
+
+	LASSERT(cache != NULL);
+
+	if (cache->fci_cache_count < cache->fci_cache_size)
+		return 0;
+
+	curr = cache->fci_lru.prev;
+
+	while (cache->fci_cache_count + cache->fci_threshold >
+	       cache->fci_cache_size && curr != &cache->fci_lru) {
+
+		flde = list_entry(curr, struct fld_cache_entry, fce_lru);
+		curr = curr->prev;
+		fld_cache_entry_delete(cache, flde);
+		num++;
+	}
+
+	CDEBUG(D_INFO, "%s: FLD cache - Shrunk by %d entries\n",
+			cache->fci_name, num);
+
+	return 0;
+}
+
+/**
+ * kill all fld cache entries.
+ */
+void fld_cache_flush(struct fld_cache *cache)
+{
+	write_lock(&cache->fci_lock);
+	cache->fci_cache_size = 0;
+	fld_cache_shrink(cache);
+	write_unlock(&cache->fci_lock);
+}
+
+/**
+ * punch hole in existing range. divide this range and add new
+ * entry accordingly.
+ */
+
+static void fld_cache_punch_hole(struct fld_cache *cache,
+				 struct fld_cache_entry *f_curr,
+				 struct fld_cache_entry *f_new)
+{
+	const struct lu_seq_range *range = &f_new->fce_range;
+	const u64 new_start  = range->lsr_start;
+	const u64 new_end  = range->lsr_end;
+	struct fld_cache_entry *fldt;
+
+	OBD_ALLOC_GFP(fldt, sizeof(*fldt), GFP_ATOMIC);
+	if (!fldt) {
+		OBD_FREE_PTR(f_new);
+		/* overlap is not allowed, so dont mess up list. */
+		return;
+	}
+	/*  break f_curr RANGE into three RANGES:
+	 *	f_curr, f_new , fldt
+	 */
+
+	/* f_new = *range */
+
+	/* fldt */
+	fldt->fce_range.lsr_start = new_end;
+	fldt->fce_range.lsr_end = f_curr->fce_range.lsr_end;
+	fldt->fce_range.lsr_index = f_curr->fce_range.lsr_index;
+
+	/* f_curr */
+	f_curr->fce_range.lsr_end = new_start;
+
+	/* add these two entries to list */
+	fld_cache_entry_add(cache, f_new, &f_curr->fce_list);
+	fld_cache_entry_add(cache, fldt, &f_new->fce_list);
+
+	/* no need to fixup */
+}
+
+/**
+ * handle range overlap in fld cache.
+ */
+static void fld_cache_overlap_handle(struct fld_cache *cache,
+				struct fld_cache_entry *f_curr,
+				struct fld_cache_entry *f_new)
+{
+	const struct lu_seq_range *range = &f_new->fce_range;
+	const u64 new_start  = range->lsr_start;
+	const u64 new_end  = range->lsr_end;
+	const u32 mdt = range->lsr_index;
+
+	/* this is overlap case, these case are checking overlapping with
+	 * prev range only. fixup will handle overlapping with next range. */
+
+	if (f_curr->fce_range.lsr_index == mdt) {
+		f_curr->fce_range.lsr_start = min(f_curr->fce_range.lsr_start,
+						  new_start);
+
+		f_curr->fce_range.lsr_end = max(f_curr->fce_range.lsr_end,
+						new_end);
+
+		OBD_FREE_PTR(f_new);
+		fld_fix_new_list(cache);
+
+	} else if (new_start <= f_curr->fce_range.lsr_start &&
+			f_curr->fce_range.lsr_end <= new_end) {
+		/* case 1: new range completely overshadowed existing range.
+		 *	 e.g. whole range migrated. update fld cache entry */
+
+		f_curr->fce_range = *range;
+		OBD_FREE_PTR(f_new);
+		fld_fix_new_list(cache);
+
+	} else if (f_curr->fce_range.lsr_start < new_start &&
+			new_end < f_curr->fce_range.lsr_end) {
+		/* case 2: new range fit within existing range. */
+
+		fld_cache_punch_hole(cache, f_curr, f_new);
+
+	} else  if (new_end <= f_curr->fce_range.lsr_end) {
+		/* case 3: overlap:
+		 *	 [new_start [c_start  new_end)  c_end)
+		 */
+
+		LASSERT(new_start <= f_curr->fce_range.lsr_start);
+
+		f_curr->fce_range.lsr_start = new_end;
+		fld_cache_entry_add(cache, f_new, f_curr->fce_list.prev);
+
+	} else if (f_curr->fce_range.lsr_start <= new_start) {
+		/* case 4: overlap:
+		 *	 [c_start [new_start c_end) new_end)
+		 */
+
+		LASSERT(f_curr->fce_range.lsr_end <= new_end);
+
+		f_curr->fce_range.lsr_end = new_start;
+		fld_cache_entry_add(cache, f_new, &f_curr->fce_list);
+	} else
+		CERROR("NEW range ="DRANGE" curr = "DRANGE"\n",
+		       PRANGE(range), PRANGE(&f_curr->fce_range));
+}
+
+struct fld_cache_entry
+*fld_cache_entry_create(const struct lu_seq_range *range)
+{
+	struct fld_cache_entry *f_new;
+
+	LASSERT(range_is_sane(range));
+
+	OBD_ALLOC_PTR(f_new);
+	if (!f_new)
+		return ERR_PTR(-ENOMEM);
+
+	f_new->fce_range = *range;
+	return f_new;
+}
+
+/**
+ * Insert FLD entry in FLD cache.
+ *
+ * This function handles all cases of merging and breaking up of
+ * ranges.
+ */
+int fld_cache_insert_nolock(struct fld_cache *cache,
+			    struct fld_cache_entry *f_new)
+{
+	struct fld_cache_entry *f_curr;
+	struct fld_cache_entry *n;
+	struct list_head *head;
+	struct list_head *prev = NULL;
+	const u64 new_start  = f_new->fce_range.lsr_start;
+	const u64 new_end  = f_new->fce_range.lsr_end;
+	__u32 new_flags  = f_new->fce_range.lsr_flags;
+
+	/*
+	 * Duplicate entries are eliminated in insert op.
+	 * So we don't need to search new entry before starting
+	 * insertion loop.
+	 */
+
+	if (!cache->fci_no_shrink)
+		fld_cache_shrink(cache);
+
+	head = &cache->fci_entries_head;
+
+	list_for_each_entry_safe(f_curr, n, head, fce_list) {
+		/* add list if next is end of list */
+		if (new_end < f_curr->fce_range.lsr_start ||
+		   (new_end == f_curr->fce_range.lsr_start &&
+		    new_flags != f_curr->fce_range.lsr_flags))
+			break;
+
+		prev = &f_curr->fce_list;
+		/* check if this range is to left of new range. */
+		if (new_start < f_curr->fce_range.lsr_end &&
+		    new_flags == f_curr->fce_range.lsr_flags) {
+			fld_cache_overlap_handle(cache, f_curr, f_new);
+			goto out;
+		}
+	}
+
+	if (prev == NULL)
+		prev = head;
+
+	CDEBUG(D_INFO, "insert range "DRANGE"\n", PRANGE(&f_new->fce_range));
+	/* Add new entry to cache and lru list. */
+	fld_cache_entry_add(cache, f_new, prev);
+out:
+	return 0;
+}
+
+int fld_cache_insert(struct fld_cache *cache,
+		     const struct lu_seq_range *range)
+{
+	struct fld_cache_entry	*flde;
+	int rc;
+
+	flde = fld_cache_entry_create(range);
+	if (IS_ERR(flde))
+		return PTR_ERR(flde);
+
+	write_lock(&cache->fci_lock);
+	rc = fld_cache_insert_nolock(cache, flde);
+	write_unlock(&cache->fci_lock);
+	if (rc)
+		OBD_FREE_PTR(flde);
+
+	return rc;
+}
+
+void fld_cache_delete_nolock(struct fld_cache *cache,
+		      const struct lu_seq_range *range)
+{
+	struct fld_cache_entry *flde;
+	struct fld_cache_entry *tmp;
+	struct list_head *head;
+
+	head = &cache->fci_entries_head;
+	list_for_each_entry_safe(flde, tmp, head, fce_list) {
+		/* add list if next is end of list */
+		if (range->lsr_start == flde->fce_range.lsr_start ||
+		   (range->lsr_end == flde->fce_range.lsr_end &&
+		    range->lsr_flags == flde->fce_range.lsr_flags)) {
+			fld_cache_entry_delete(cache, flde);
+			break;
+		}
+	}
+}
+
+/**
+ * Delete FLD entry in FLD cache.
+ *
+ */
+void fld_cache_delete(struct fld_cache *cache,
+		      const struct lu_seq_range *range)
+{
+	write_lock(&cache->fci_lock);
+	fld_cache_delete_nolock(cache, range);
+	write_unlock(&cache->fci_lock);
+}
+
+struct fld_cache_entry
+*fld_cache_entry_lookup_nolock(struct fld_cache *cache,
+			      struct lu_seq_range *range)
+{
+	struct fld_cache_entry *flde;
+	struct fld_cache_entry *got = NULL;
+	struct list_head *head;
+
+	head = &cache->fci_entries_head;
+	list_for_each_entry(flde, head, fce_list) {
+		if (range->lsr_start == flde->fce_range.lsr_start ||
+		   (range->lsr_end == flde->fce_range.lsr_end &&
+		    range->lsr_flags == flde->fce_range.lsr_flags)) {
+			got = flde;
+			break;
+		}
+	}
+
+	return got;
+}
+
+/**
+ * lookup \a seq sequence for range in fld cache.
+ */
+struct fld_cache_entry
+*fld_cache_entry_lookup(struct fld_cache *cache, struct lu_seq_range *range)
+{
+	struct fld_cache_entry *got = NULL;
+
+	read_lock(&cache->fci_lock);
+	got = fld_cache_entry_lookup_nolock(cache, range);
+	read_unlock(&cache->fci_lock);
+	return got;
+}
+
+/**
+ * lookup \a seq sequence for range in fld cache.
+ */
+int fld_cache_lookup(struct fld_cache *cache,
+		     const u64 seq, struct lu_seq_range *range)
+{
+	struct fld_cache_entry *flde;
+	struct fld_cache_entry *prev = NULL;
+	struct list_head *head;
+
+	read_lock(&cache->fci_lock);
+	head = &cache->fci_entries_head;
+
+	cache->fci_stat.fst_count++;
+	list_for_each_entry(flde, head, fce_list) {
+		if (flde->fce_range.lsr_start > seq) {
+			if (prev != NULL)
+				*range = prev->fce_range;
+			break;
+		}
+
+		prev = flde;
+		if (range_within(&flde->fce_range, seq)) {
+			*range = flde->fce_range;
+
+			cache->fci_stat.fst_cache++;
+			read_unlock(&cache->fci_lock);
+			return 0;
+		}
+	}
+	read_unlock(&cache->fci_lock);
+	return -ENOENT;
+}
diff --git a/drivers/staging/lustre/lustre/fld/fld_internal.h b/drivers/staging/lustre/lustre/fld/fld_internal.h
new file mode 100644
index 000000000..68bec7658
--- /dev/null
+++ b/drivers/staging/lustre/lustre/fld/fld_internal.h
@@ -0,0 +1,193 @@
+/*
+ * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, 2013, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/fld/fld_internal.h
+ *
+ * Author: Yury Umanets <umka@clusterfs.com>
+ * Author: Tom WangDi <wangdi@clusterfs.com>
+ */
+#ifndef __FLD_INTERNAL_H
+#define __FLD_INTERNAL_H
+
+#include "../include/lustre/lustre_idl.h"
+#include "../include/dt_object.h"
+
+#include "../../include/linux/libcfs/libcfs.h"
+#include "../include/lustre_req_layout.h"
+#include "../include/lustre_fld.h"
+
+enum {
+	LUSTRE_FLD_INIT = 1 << 0,
+	LUSTRE_FLD_RUN  = 1 << 1
+};
+
+struct fld_stats {
+	__u64   fst_count;
+	__u64   fst_cache;
+	__u64   fst_inflight;
+};
+
+typedef int (*fld_hash_func_t) (struct lu_client_fld *, __u64);
+
+typedef struct lu_fld_target *
+(*fld_scan_func_t) (struct lu_client_fld *, __u64);
+
+struct lu_fld_hash {
+	const char	      *fh_name;
+	fld_hash_func_t	  fh_hash_func;
+	fld_scan_func_t	  fh_scan_func;
+};
+
+struct fld_cache_entry {
+	struct list_head	       fce_lru;
+	struct list_head	       fce_list;
+	/**
+	 * fld cache entries are sorted on range->lsr_start field. */
+	struct lu_seq_range      fce_range;
+};
+
+struct fld_cache {
+	/**
+	 * Cache guard, protects fci_hash mostly because others immutable after
+	 * init is finished.
+	 */
+	rwlock_t		 fci_lock;
+
+	/**
+	 * Cache shrink threshold */
+	int		      fci_threshold;
+
+	/**
+	 * Preferred number of cached entries */
+	int		      fci_cache_size;
+
+	/**
+	 * Current number of cached entries. Protected by \a fci_lock */
+	int		      fci_cache_count;
+
+	/**
+	 * LRU list fld entries. */
+	struct list_head	       fci_lru;
+
+	/**
+	 * sorted fld entries. */
+	struct list_head	       fci_entries_head;
+
+	/**
+	 * Cache statistics. */
+	struct fld_stats	 fci_stat;
+
+	/**
+	 * Cache name used for debug and messages. */
+	char		     fci_name[LUSTRE_MDT_MAXNAMELEN];
+	unsigned int		 fci_no_shrink:1;
+};
+
+enum fld_op {
+	FLD_CREATE = 0,
+	FLD_DELETE = 1,
+	FLD_LOOKUP = 2
+};
+
+enum {
+	/* 4M of FLD cache will not hurt client a lot. */
+	FLD_SERVER_CACHE_SIZE      = (4 * 0x100000),
+
+	/* 1M of FLD cache will not hurt client a lot. */
+	FLD_CLIENT_CACHE_SIZE      = (1 * 0x100000)
+};
+
+enum {
+	/* Cache threshold is 10 percent of size. */
+	FLD_SERVER_CACHE_THRESHOLD = 10,
+
+	/* Cache threshold is 10 percent of size. */
+	FLD_CLIENT_CACHE_THRESHOLD = 10
+};
+
+extern struct lu_fld_hash fld_hash[];
+
+int fld_client_rpc(struct obd_export *exp,
+		   struct lu_seq_range *range, __u32 fld_op);
+
+#if defined(CONFIG_PROC_FS)
+extern struct lprocfs_vars fld_client_proc_list[];
+#endif
+
+
+struct fld_cache *fld_cache_init(const char *name,
+				 int cache_size, int cache_threshold);
+
+void fld_cache_fini(struct fld_cache *cache);
+
+void fld_cache_flush(struct fld_cache *cache);
+
+int fld_cache_insert(struct fld_cache *cache,
+		     const struct lu_seq_range *range);
+
+struct fld_cache_entry
+*fld_cache_entry_create(const struct lu_seq_range *range);
+
+int fld_cache_insert_nolock(struct fld_cache *cache,
+			    struct fld_cache_entry *f_new);
+void fld_cache_delete(struct fld_cache *cache,
+		      const struct lu_seq_range *range);
+void fld_cache_delete_nolock(struct fld_cache *cache,
+			     const struct lu_seq_range *range);
+int fld_cache_lookup(struct fld_cache *cache,
+		     const u64 seq, struct lu_seq_range *range);
+
+struct fld_cache_entry*
+fld_cache_entry_lookup(struct fld_cache *cache, struct lu_seq_range *range);
+void fld_cache_entry_delete(struct fld_cache *cache,
+			    struct fld_cache_entry *node);
+void fld_dump_cache_entries(struct fld_cache *cache);
+
+struct fld_cache_entry
+*fld_cache_entry_lookup_nolock(struct fld_cache *cache,
+			      struct lu_seq_range *range);
+int fld_write_range(const struct lu_env *env, struct dt_object *dt,
+		    const struct lu_seq_range *range, struct thandle *th);
+
+static inline const char *
+fld_target_name(struct lu_fld_target *tar)
+{
+	if (tar->ft_srv != NULL)
+		return tar->ft_srv->lsf_name;
+
+	return (const char *)tar->ft_exp->exp_obd->obd_name;
+}
+
+#endif /* __FLD_INTERNAL_H */
diff --git a/drivers/staging/lustre/lustre/fld/fld_request.c b/drivers/staging/lustre/lustre/fld/fld_request.c
new file mode 100644
index 000000000..6ac225e90
--- /dev/null
+++ b/drivers/staging/lustre/lustre/fld/fld_request.c
@@ -0,0 +1,526 @@
+/*
+ * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2013, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/fld/fld_request.c
+ *
+ * FLD (Fids Location Database)
+ *
+ * Author: Yury Umanets <umka@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_FLD
+
+#include "../../include/linux/libcfs/libcfs.h"
+#include <linux/module.h>
+#include <asm/div64.h>
+
+#include "../include/obd.h"
+#include "../include/obd_class.h"
+#include "../include/lustre_ver.h"
+#include "../include/obd_support.h"
+#include "../include/lprocfs_status.h"
+
+#include "../include/dt_object.h"
+#include "../include/lustre_req_layout.h"
+#include "../include/lustre_fld.h"
+#include "../include/lustre_mdc.h"
+#include "fld_internal.h"
+
+/* TODO: these 3 functions are copies of flow-control code from mdc_lib.c
+ * It should be common thing. The same about mdc RPC lock */
+static int fld_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
+{
+	int rc;
+
+	client_obd_list_lock(&cli->cl_loi_list_lock);
+	rc = list_empty(&mcw->mcw_entry);
+	client_obd_list_unlock(&cli->cl_loi_list_lock);
+	return rc;
+};
+
+static void fld_enter_request(struct client_obd *cli)
+{
+	struct mdc_cache_waiter mcw;
+	struct l_wait_info lwi = { 0 };
+
+	client_obd_list_lock(&cli->cl_loi_list_lock);
+	if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
+		list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
+		init_waitqueue_head(&mcw.mcw_waitq);
+		client_obd_list_unlock(&cli->cl_loi_list_lock);
+		l_wait_event(mcw.mcw_waitq, fld_req_avail(cli, &mcw), &lwi);
+	} else {
+		cli->cl_r_in_flight++;
+		client_obd_list_unlock(&cli->cl_loi_list_lock);
+	}
+}
+
+static void fld_exit_request(struct client_obd *cli)
+{
+	struct list_head *l, *tmp;
+	struct mdc_cache_waiter *mcw;
+
+	client_obd_list_lock(&cli->cl_loi_list_lock);
+	cli->cl_r_in_flight--;
+	list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
+
+		if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
+			/* No free request slots anymore */
+			break;
+		}
+
+		mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
+		list_del_init(&mcw->mcw_entry);
+		cli->cl_r_in_flight++;
+		wake_up(&mcw->mcw_waitq);
+	}
+	client_obd_list_unlock(&cli->cl_loi_list_lock);
+}
+
+static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
+{
+	LASSERT(fld->lcf_count > 0);
+	return do_div(seq, fld->lcf_count);
+}
+
+static struct lu_fld_target *
+fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
+{
+	struct lu_fld_target *target;
+	int hash;
+
+	/* Because almost all of special sequence located in MDT0,
+	 * it should go to index 0 directly, instead of calculating
+	 * hash again, and also if other MDTs is not being connected,
+	 * the fld lookup requests(for seq on MDT0) should not be
+	 * blocked because of other MDTs */
+	if (fid_seq_is_norm(seq))
+		hash = fld_rrb_hash(fld, seq);
+	else
+		hash = 0;
+
+again:
+	list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
+		if (target->ft_idx == hash)
+			return target;
+	}
+
+	if (hash != 0) {
+		/* It is possible the remote target(MDT) are not connected to
+		 * with client yet, so we will refer this to MDT0, which should
+		 * be connected during mount */
+		hash = 0;
+		goto again;
+	}
+
+	CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
+		fld->lcf_name, hash, seq, fld->lcf_count);
+
+	list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
+		const char *srv_name = target->ft_srv != NULL  ?
+			target->ft_srv->lsf_name : "<null>";
+		const char *exp_name = target->ft_exp != NULL ?
+			(char *)target->ft_exp->exp_obd->obd_uuid.uuid :
+			"<null>";
+
+		CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
+		       target->ft_exp, exp_name, target->ft_srv,
+		       srv_name, target->ft_idx);
+	}
+
+	/*
+	 * If target is not found, there is logical error anyway, so here is
+	 * LBUG() to catch this situation.
+	 */
+	LBUG();
+	return NULL;
+}
+
+struct lu_fld_hash fld_hash[] = {
+	{
+		.fh_name = "RRB",
+		.fh_hash_func = fld_rrb_hash,
+		.fh_scan_func = fld_rrb_scan
+	},
+	{
+		NULL,
+	}
+};
+
+static struct lu_fld_target *
+fld_client_get_target(struct lu_client_fld *fld, u64 seq)
+{
+	struct lu_fld_target *target;
+
+	LASSERT(fld->lcf_hash != NULL);
+
+	spin_lock(&fld->lcf_lock);
+	target = fld->lcf_hash->fh_scan_func(fld, seq);
+	spin_unlock(&fld->lcf_lock);
+
+	if (target != NULL) {
+		CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
+		       fld->lcf_name, target->ft_idx, seq);
+	}
+
+	return target;
+}
+
+/*
+ * Add export to FLD. This is usually done by CMM and LMV as they are main users
+ * of FLD module.
+ */
+int fld_client_add_target(struct lu_client_fld *fld,
+			  struct lu_fld_target *tar)
+{
+	const char *name;
+	struct lu_fld_target *target, *tmp;
+
+	LASSERT(tar != NULL);
+	name = fld_target_name(tar);
+	LASSERT(name != NULL);
+	LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
+
+	if (fld->lcf_flags != LUSTRE_FLD_INIT) {
+		CERROR("%s: Attempt to add target %s (idx %llu) on fly - skip it\n",
+			fld->lcf_name, name, tar->ft_idx);
+		return 0;
+	}
+	CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n",
+			fld->lcf_name, name, tar->ft_idx);
+
+	OBD_ALLOC_PTR(target);
+	if (target == NULL)
+		return -ENOMEM;
+
+	spin_lock(&fld->lcf_lock);
+	list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
+		if (tmp->ft_idx == tar->ft_idx) {
+			spin_unlock(&fld->lcf_lock);
+			OBD_FREE_PTR(target);
+			CERROR("Target %s exists in FLD and known as %s:#%llu\n",
+			       name, fld_target_name(tmp), tmp->ft_idx);
+			return -EEXIST;
+		}
+	}
+
+	target->ft_exp = tar->ft_exp;
+	if (target->ft_exp != NULL)
+		class_export_get(target->ft_exp);
+	target->ft_srv = tar->ft_srv;
+	target->ft_idx = tar->ft_idx;
+
+	list_add_tail(&target->ft_chain,
+			  &fld->lcf_targets);
+
+	fld->lcf_count++;
+	spin_unlock(&fld->lcf_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(fld_client_add_target);
+
+/* Remove export from FLD */
+int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
+{
+	struct lu_fld_target *target, *tmp;
+
+	spin_lock(&fld->lcf_lock);
+	list_for_each_entry_safe(target, tmp,
+				     &fld->lcf_targets, ft_chain) {
+		if (target->ft_idx == idx) {
+			fld->lcf_count--;
+			list_del(&target->ft_chain);
+			spin_unlock(&fld->lcf_lock);
+
+			if (target->ft_exp != NULL)
+				class_export_put(target->ft_exp);
+
+			OBD_FREE_PTR(target);
+			return 0;
+		}
+	}
+	spin_unlock(&fld->lcf_lock);
+	return -ENOENT;
+}
+EXPORT_SYMBOL(fld_client_del_target);
+
+static struct proc_dir_entry *fld_type_proc_dir;
+
+#if defined(CONFIG_PROC_FS)
+static int fld_client_proc_init(struct lu_client_fld *fld)
+{
+	int rc;
+
+	fld->lcf_proc_dir = lprocfs_register(fld->lcf_name,
+					     fld_type_proc_dir,
+					     NULL, NULL);
+
+	if (IS_ERR(fld->lcf_proc_dir)) {
+		CERROR("%s: LProcFS failed in fld-init\n",
+		       fld->lcf_name);
+		rc = PTR_ERR(fld->lcf_proc_dir);
+		return rc;
+	}
+
+	rc = lprocfs_add_vars(fld->lcf_proc_dir,
+			      fld_client_proc_list, fld);
+	if (rc) {
+		CERROR("%s: Can't init FLD proc, rc %d\n",
+		       fld->lcf_name, rc);
+		goto out_cleanup;
+	}
+
+	return 0;
+
+out_cleanup:
+	fld_client_proc_fini(fld);
+	return rc;
+}
+
+void fld_client_proc_fini(struct lu_client_fld *fld)
+{
+	if (fld->lcf_proc_dir) {
+		if (!IS_ERR(fld->lcf_proc_dir))
+			lprocfs_remove(&fld->lcf_proc_dir);
+		fld->lcf_proc_dir = NULL;
+	}
+}
+#else
+static int fld_client_proc_init(struct lu_client_fld *fld)
+{
+	return 0;
+}
+
+void fld_client_proc_fini(struct lu_client_fld *fld)
+{
+}
+#endif
+EXPORT_SYMBOL(fld_client_proc_fini);
+
+static inline int hash_is_sane(int hash)
+{
+	return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
+}
+
+int fld_client_init(struct lu_client_fld *fld,
+		    const char *prefix, int hash)
+{
+	int cache_size, cache_threshold;
+	int rc;
+
+	LASSERT(fld != NULL);
+
+	snprintf(fld->lcf_name, sizeof(fld->lcf_name),
+		 "cli-%s", prefix);
+
+	if (!hash_is_sane(hash)) {
+		CERROR("%s: Wrong hash function %#x\n",
+		       fld->lcf_name, hash);
+		return -EINVAL;
+	}
+
+	fld->lcf_count = 0;
+	spin_lock_init(&fld->lcf_lock);
+	fld->lcf_hash = &fld_hash[hash];
+	fld->lcf_flags = LUSTRE_FLD_INIT;
+	INIT_LIST_HEAD(&fld->lcf_targets);
+
+	cache_size = FLD_CLIENT_CACHE_SIZE /
+		sizeof(struct fld_cache_entry);
+
+	cache_threshold = cache_size *
+		FLD_CLIENT_CACHE_THRESHOLD / 100;
+
+	fld->lcf_cache = fld_cache_init(fld->lcf_name,
+					cache_size, cache_threshold);
+	if (IS_ERR(fld->lcf_cache)) {
+		rc = PTR_ERR(fld->lcf_cache);
+		fld->lcf_cache = NULL;
+		goto out;
+	}
+
+	rc = fld_client_proc_init(fld);
+	if (rc)
+		goto out;
+out:
+	if (rc)
+		fld_client_fini(fld);
+	else
+		CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
+		       fld->lcf_name, fld->lcf_hash->fh_name);
+	return rc;
+}
+EXPORT_SYMBOL(fld_client_init);
+
+void fld_client_fini(struct lu_client_fld *fld)
+{
+	struct lu_fld_target *target, *tmp;
+
+	spin_lock(&fld->lcf_lock);
+	list_for_each_entry_safe(target, tmp,
+				     &fld->lcf_targets, ft_chain) {
+		fld->lcf_count--;
+		list_del(&target->ft_chain);
+		if (target->ft_exp != NULL)
+			class_export_put(target->ft_exp);
+		OBD_FREE_PTR(target);
+	}
+	spin_unlock(&fld->lcf_lock);
+
+	if (fld->lcf_cache != NULL) {
+		if (!IS_ERR(fld->lcf_cache))
+			fld_cache_fini(fld->lcf_cache);
+		fld->lcf_cache = NULL;
+	}
+}
+EXPORT_SYMBOL(fld_client_fini);
+
+int fld_client_rpc(struct obd_export *exp,
+		   struct lu_seq_range *range, __u32 fld_op)
+{
+	struct ptlrpc_request *req;
+	struct lu_seq_range   *prange;
+	__u32		 *op;
+	int		    rc;
+	struct obd_import     *imp;
+
+	LASSERT(exp != NULL);
+
+	imp = class_exp2cliimp(exp);
+	req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
+					FLD_QUERY);
+	if (req == NULL)
+		return -ENOMEM;
+
+	op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
+	*op = fld_op;
+
+	prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
+	*prange = *range;
+
+	ptlrpc_request_set_replen(req);
+	req->rq_request_portal = FLD_REQUEST_PORTAL;
+	req->rq_reply_portal = MDC_REPLY_PORTAL;
+	ptlrpc_at_set_req_timeout(req);
+
+	if (fld_op == FLD_LOOKUP &&
+	    imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
+		req->rq_allow_replay = 1;
+
+	if (fld_op != FLD_LOOKUP)
+		mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
+	fld_enter_request(&exp->exp_obd->u.cli);
+	rc = ptlrpc_queue_wait(req);
+	fld_exit_request(&exp->exp_obd->u.cli);
+	if (fld_op != FLD_LOOKUP)
+		mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
+	if (rc)
+		goto out_req;
+
+	prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
+	if (prange == NULL) {
+		rc = -EFAULT;
+		goto out_req;
+	}
+	*range = *prange;
+out_req:
+	ptlrpc_req_finished(req);
+	return rc;
+}
+
+int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
+		      __u32 flags, const struct lu_env *env)
+{
+	struct lu_seq_range res = { 0 };
+	struct lu_fld_target *target;
+	int rc;
+
+	fld->lcf_flags |= LUSTRE_FLD_RUN;
+
+	rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
+	if (rc == 0) {
+		*mds = res.lsr_index;
+		return 0;
+	}
+
+	/* Can not find it in the cache */
+	target = fld_client_get_target(fld, seq);
+	LASSERT(target != NULL);
+
+	CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
+			fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
+
+	res.lsr_start = seq;
+	fld_range_set_type(&res, flags);
+	rc = fld_client_rpc(target->ft_exp, &res, FLD_LOOKUP);
+
+	if (rc == 0) {
+		*mds = res.lsr_index;
+
+		fld_cache_insert(fld->lcf_cache, &res);
+	}
+	return rc;
+}
+EXPORT_SYMBOL(fld_client_lookup);
+
+void fld_client_flush(struct lu_client_fld *fld)
+{
+	fld_cache_flush(fld->lcf_cache);
+}
+EXPORT_SYMBOL(fld_client_flush);
+
+static int __init fld_mod_init(void)
+{
+	fld_type_proc_dir = lprocfs_register(LUSTRE_FLD_NAME,
+					     proc_lustre_root,
+					     NULL, NULL);
+	return PTR_ERR_OR_ZERO(fld_type_proc_dir);
+}
+
+static void __exit fld_mod_exit(void)
+{
+	if (fld_type_proc_dir != NULL && !IS_ERR(fld_type_proc_dir)) {
+		lprocfs_remove(&fld_type_proc_dir);
+		fld_type_proc_dir = NULL;
+	}
+}
+
+MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
+MODULE_DESCRIPTION("Lustre FLD");
+MODULE_LICENSE("GPL");
+
+module_init(fld_mod_init)
+module_exit(fld_mod_exit)
diff --git a/drivers/staging/lustre/lustre/fld/lproc_fld.c b/drivers/staging/lustre/lustre/fld/lproc_fld.c
new file mode 100644
index 000000000..f53fdcfae
--- /dev/null
+++ b/drivers/staging/lustre/lustre/fld/lproc_fld.c
@@ -0,0 +1,172 @@
+/*
+ * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, 2013, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/fld/lproc_fld.c
+ *
+ * FLD (FIDs Location Database)
+ *
+ * Author: Yury Umanets <umka@clusterfs.com>
+ *	Di Wang <di.wang@whamcloud.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_FLD
+
+#include "../../include/linux/libcfs/libcfs.h"
+#include <linux/module.h>
+
+#include "../include/obd.h"
+#include "../include/obd_class.h"
+#include "../include/dt_object.h"
+#include "../include/obd_support.h"
+#include "../include/lustre_req_layout.h"
+#include "../include/lustre_fld.h"
+#include "../include/lustre_fid.h"
+#include "fld_internal.h"
+
+static int
+fld_proc_targets_seq_show(struct seq_file *m, void *unused)
+{
+	struct lu_client_fld *fld = (struct lu_client_fld *)m->private;
+	struct lu_fld_target *target;
+
+	LASSERT(fld != NULL);
+
+	spin_lock(&fld->lcf_lock);
+	list_for_each_entry(target,
+				&fld->lcf_targets, ft_chain)
+		seq_printf(m, "%s\n", fld_target_name(target));
+	spin_unlock(&fld->lcf_lock);
+
+	return 0;
+}
+
+static int
+fld_proc_hash_seq_show(struct seq_file *m, void *unused)
+{
+	struct lu_client_fld *fld = (struct lu_client_fld *)m->private;
+
+	LASSERT(fld != NULL);
+
+	spin_lock(&fld->lcf_lock);
+	seq_printf(m, "%s\n", fld->lcf_hash->fh_name);
+	spin_unlock(&fld->lcf_lock);
+
+	return 0;
+}
+
+static ssize_t
+fld_proc_hash_seq_write(struct file *file,
+				const char __user *buffer,
+				size_t count, loff_t *off)
+{
+	struct lu_client_fld *fld;
+	struct lu_fld_hash *hash = NULL;
+	char fh_name[8];
+	int i;
+
+	if (count > sizeof(fh_name))
+		return -ENAMETOOLONG;
+
+	if (copy_from_user(fh_name, buffer, count) != 0)
+		return -EFAULT;
+
+	fld = ((struct seq_file *)file->private_data)->private;
+	LASSERT(fld != NULL);
+
+	for (i = 0; fld_hash[i].fh_name != NULL; i++) {
+		if (count != strlen(fld_hash[i].fh_name))
+			continue;
+
+		if (!strncmp(fld_hash[i].fh_name, fh_name, count)) {
+			hash = &fld_hash[i];
+			break;
+		}
+	}
+
+	if (hash != NULL) {
+		spin_lock(&fld->lcf_lock);
+		fld->lcf_hash = hash;
+		spin_unlock(&fld->lcf_lock);
+
+		CDEBUG(D_INFO, "%s: Changed hash to \"%s\"\n",
+		       fld->lcf_name, hash->fh_name);
+	}
+
+	return count;
+}
+
+static ssize_t
+fld_proc_cache_flush_write(struct file *file, const char __user *buffer,
+			       size_t count, loff_t *pos)
+{
+	struct lu_client_fld *fld = file->private_data;
+
+	LASSERT(fld != NULL);
+
+	fld_cache_flush(fld->lcf_cache);
+
+	CDEBUG(D_INFO, "%s: Lookup cache is flushed\n", fld->lcf_name);
+
+	return count;
+}
+
+static int fld_proc_cache_flush_open(struct inode *inode, struct file *file)
+{
+	file->private_data = PDE_DATA(inode);
+	return 0;
+}
+
+static int fld_proc_cache_flush_release(struct inode *inode, struct file *file)
+{
+	file->private_data = NULL;
+	return 0;
+}
+
+static struct file_operations fld_proc_cache_flush_fops = {
+	.owner		= THIS_MODULE,
+	.open		= fld_proc_cache_flush_open,
+	.write		= fld_proc_cache_flush_write,
+	.release	= fld_proc_cache_flush_release,
+};
+
+LPROC_SEQ_FOPS_RO(fld_proc_targets);
+LPROC_SEQ_FOPS(fld_proc_hash);
+
+struct lprocfs_vars fld_client_proc_list[] = {
+	{ "targets", &fld_proc_targets_fops },
+	{ "hash", &fld_proc_hash_fops },
+	{ "cache_flush", &fld_proc_cache_flush_fops },
+	{ NULL }
+};