--- /dev/null
+/*
+ * 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, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/obdclass/lu_object.c
+ *
+ * Lustre Object.
+ * These are the only exported functions, they provide some generic
+ * infrastructure for managing object devices
+ *
+ * Author: Nikita Danilov <nikita.danilov@sun.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_CLASS
+
+#include "../../include/linux/libcfs/libcfs.h"
+
+# include <linux/module.h>
+
+/* hash_long() */
+#include "../../include/linux/libcfs/libcfs_hash.h"
+#include "../include/obd_class.h"
+#include "../include/obd_support.h"
+#include "../include/lustre_disk.h"
+#include "../include/lustre_fid.h"
+#include "../include/lu_object.h"
+#include "../include/lu_ref.h"
+#include <linux/list.h>
+
+static void lu_object_free(const struct lu_env *env, struct lu_object *o);
+
+/**
+ * Decrease reference counter on object. If last reference is freed, return
+ * object to the cache, unless lu_object_is_dying(o) holds. In the latter
+ * case, free object immediately.
+ */
+void lu_object_put(const struct lu_env *env, struct lu_object *o)
+{
+ struct lu_site_bkt_data *bkt;
+ struct lu_object_header *top;
+ struct lu_site *site;
+ struct lu_object *orig;
+ struct cfs_hash_bd bd;
+ const struct lu_fid *fid;
+
+ top = o->lo_header;
+ site = o->lo_dev->ld_site;
+ orig = o;
+
+ /*
+ * till we have full fids-on-OST implemented anonymous objects
+ * are possible in OSP. such an object isn't listed in the site
+ * so we should not remove it from the site.
+ */
+ fid = lu_object_fid(o);
+ if (fid_is_zero(fid)) {
+ LASSERT(top->loh_hash.next == NULL
+ && top->loh_hash.pprev == NULL);
+ LASSERT(list_empty(&top->loh_lru));
+ if (!atomic_dec_and_test(&top->loh_ref))
+ return;
+ list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
+ if (o->lo_ops->loo_object_release != NULL)
+ o->lo_ops->loo_object_release(env, o);
+ }
+ lu_object_free(env, orig);
+ return;
+ }
+
+ cfs_hash_bd_get(site->ls_obj_hash, &top->loh_fid, &bd);
+ bkt = cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
+
+ if (!cfs_hash_bd_dec_and_lock(site->ls_obj_hash, &bd, &top->loh_ref)) {
+ if (lu_object_is_dying(top)) {
+
+ /*
+ * somebody may be waiting for this, currently only
+ * used for cl_object, see cl_object_put_last().
+ */
+ wake_up_all(&bkt->lsb_marche_funebre);
+ }
+ return;
+ }
+
+ LASSERT(bkt->lsb_busy > 0);
+ bkt->lsb_busy--;
+ /*
+ * When last reference is released, iterate over object
+ * layers, and notify them that object is no longer busy.
+ */
+ list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
+ if (o->lo_ops->loo_object_release != NULL)
+ o->lo_ops->loo_object_release(env, o);
+ }
+
+ if (!lu_object_is_dying(top)) {
+ LASSERT(list_empty(&top->loh_lru));
+ list_add_tail(&top->loh_lru, &bkt->lsb_lru);
+ cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
+ return;
+ }
+
+ /*
+ * If object is dying (will not be cached), removed it
+ * from hash table and LRU.
+ *
+ * This is done with hash table and LRU lists locked. As the only
+ * way to acquire first reference to previously unreferenced
+ * object is through hash-table lookup (lu_object_find()),
+ * or LRU scanning (lu_site_purge()), that are done under hash-table
+ * and LRU lock, no race with concurrent object lookup is possible
+ * and we can safely destroy object below.
+ */
+ if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags))
+ cfs_hash_bd_del_locked(site->ls_obj_hash, &bd, &top->loh_hash);
+ cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
+ /*
+ * Object was already removed from hash and lru above, can
+ * kill it.
+ */
+ lu_object_free(env, orig);
+}
+EXPORT_SYMBOL(lu_object_put);
+
+/**
+ * Put object and don't keep in cache. This is temporary solution for
+ * multi-site objects when its layering is not constant.
+ */
+void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o)
+{
+ set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags);
+ return lu_object_put(env, o);
+}
+EXPORT_SYMBOL(lu_object_put_nocache);
+
+/**
+ * Kill the object and take it out of LRU cache.
+ * Currently used by client code for layout change.
+ */
+void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
+{
+ struct lu_object_header *top;
+
+ top = o->lo_header;
+ set_bit(LU_OBJECT_HEARD_BANSHEE, &top->loh_flags);
+ if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) {
+ struct cfs_hash *obj_hash = o->lo_dev->ld_site->ls_obj_hash;
+ struct cfs_hash_bd bd;
+
+ cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1);
+ list_del_init(&top->loh_lru);
+ cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
+ cfs_hash_bd_unlock(obj_hash, &bd, 1);
+ }
+}
+EXPORT_SYMBOL(lu_object_unhash);
+
+/**
+ * Allocate new object.
+ *
+ * This follows object creation protocol, described in the comment within
+ * struct lu_device_operations definition.
+ */
+static struct lu_object *lu_object_alloc(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_fid *f,
+ const struct lu_object_conf *conf)
+{
+ struct lu_object *scan;
+ struct lu_object *top;
+ struct list_head *layers;
+ unsigned int init_mask = 0;
+ unsigned int init_flag;
+ int clean;
+ int result;
+
+ /*
+ * Create top-level object slice. This will also create
+ * lu_object_header.
+ */
+ top = dev->ld_ops->ldo_object_alloc(env, NULL, dev);
+ if (top == NULL)
+ return ERR_PTR(-ENOMEM);
+ if (IS_ERR(top))
+ return top;
+ /*
+ * This is the only place where object fid is assigned. It's constant
+ * after this point.
+ */
+ top->lo_header->loh_fid = *f;
+ layers = &top->lo_header->loh_layers;
+
+ do {
+ /*
+ * Call ->loo_object_init() repeatedly, until no more new
+ * object slices are created.
+ */
+ clean = 1;
+ init_flag = 1;
+ list_for_each_entry(scan, layers, lo_linkage) {
+ if (init_mask & init_flag)
+ goto next;
+ clean = 0;
+ scan->lo_header = top->lo_header;
+ result = scan->lo_ops->loo_object_init(env, scan, conf);
+ if (result != 0) {
+ lu_object_free(env, top);
+ return ERR_PTR(result);
+ }
+ init_mask |= init_flag;
+next:
+ init_flag <<= 1;
+ }
+ } while (!clean);
+
+ list_for_each_entry_reverse(scan, layers, lo_linkage) {
+ if (scan->lo_ops->loo_object_start != NULL) {
+ result = scan->lo_ops->loo_object_start(env, scan);
+ if (result != 0) {
+ lu_object_free(env, top);
+ return ERR_PTR(result);
+ }
+ }
+ }
+
+ lprocfs_counter_incr(dev->ld_site->ls_stats, LU_SS_CREATED);
+ return top;
+}
+
+/**
+ * Free an object.
+ */
+static void lu_object_free(const struct lu_env *env, struct lu_object *o)
+{
+ struct lu_site_bkt_data *bkt;
+ struct lu_site *site;
+ struct lu_object *scan;
+ struct list_head *layers;
+ struct list_head splice;
+
+ site = o->lo_dev->ld_site;
+ layers = &o->lo_header->loh_layers;
+ bkt = lu_site_bkt_from_fid(site, &o->lo_header->loh_fid);
+ /*
+ * First call ->loo_object_delete() method to release all resources.
+ */
+ list_for_each_entry_reverse(scan, layers, lo_linkage) {
+ if (scan->lo_ops->loo_object_delete != NULL)
+ scan->lo_ops->loo_object_delete(env, scan);
+ }
+
+ /*
+ * Then, splice object layers into stand-alone list, and call
+ * ->loo_object_free() on all layers to free memory. Splice is
+ * necessary, because lu_object_header is freed together with the
+ * top-level slice.
+ */
+ INIT_LIST_HEAD(&splice);
+ list_splice_init(layers, &splice);
+ while (!list_empty(&splice)) {
+ /*
+ * Free layers in bottom-to-top order, so that object header
+ * lives as long as possible and ->loo_object_free() methods
+ * can look at its contents.
+ */
+ o = container_of0(splice.prev, struct lu_object, lo_linkage);
+ list_del_init(&o->lo_linkage);
+ LASSERT(o->lo_ops->loo_object_free != NULL);
+ o->lo_ops->loo_object_free(env, o);
+ }
+
+ if (waitqueue_active(&bkt->lsb_marche_funebre))
+ wake_up_all(&bkt->lsb_marche_funebre);
+}
+
+/**
+ * Free \a nr objects from the cold end of the site LRU list.
+ */
+int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
+{
+ struct lu_object_header *h;
+ struct lu_object_header *temp;
+ struct lu_site_bkt_data *bkt;
+ struct cfs_hash_bd bd;
+ struct cfs_hash_bd bd2;
+ struct list_head dispose;
+ int did_sth;
+ int start;
+ int count;
+ int bnr;
+ int i;
+
+ if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU))
+ return 0;
+
+ INIT_LIST_HEAD(&dispose);
+ /*
+ * Under LRU list lock, scan LRU list and move unreferenced objects to
+ * the dispose list, removing them from LRU and hash table.
+ */
+ start = s->ls_purge_start;
+ bnr = (nr == ~0) ? -1 : nr / CFS_HASH_NBKT(s->ls_obj_hash) + 1;
+ again:
+ did_sth = 0;
+ cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
+ if (i < start)
+ continue;
+ count = bnr;
+ cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1);
+ bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
+
+ list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) {
+ LASSERT(atomic_read(&h->loh_ref) == 0);
+
+ cfs_hash_bd_get(s->ls_obj_hash, &h->loh_fid, &bd2);
+ LASSERT(bd.bd_bucket == bd2.bd_bucket);
+
+ cfs_hash_bd_del_locked(s->ls_obj_hash,
+ &bd2, &h->loh_hash);
+ list_move(&h->loh_lru, &dispose);
+ if (did_sth == 0)
+ did_sth = 1;
+
+ if (nr != ~0 && --nr == 0)
+ break;
+
+ if (count > 0 && --count == 0)
+ break;
+
+ }
+ cfs_hash_bd_unlock(s->ls_obj_hash, &bd, 1);
+ cond_resched();
+ /*
+ * Free everything on the dispose list. This is safe against
+ * races due to the reasons described in lu_object_put().
+ */
+ while (!list_empty(&dispose)) {
+ h = container_of0(dispose.next,
+ struct lu_object_header, loh_lru);
+ list_del_init(&h->loh_lru);
+ lu_object_free(env, lu_object_top(h));
+ lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED);
+ }
+
+ if (nr == 0)
+ break;
+ }
+
+ if (nr != 0 && did_sth && start != 0) {
+ start = 0; /* restart from the first bucket */
+ goto again;
+ }
+ /* race on s->ls_purge_start, but nobody cares */
+ s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash);
+
+ return nr;
+}
+EXPORT_SYMBOL(lu_site_purge);
+
+/*
+ * Object printing.
+ *
+ * Code below has to jump through certain loops to output object description
+ * into libcfs_debug_msg-based log. The problem is that lu_object_print()
+ * composes object description from strings that are parts of _lines_ of
+ * output (i.e., strings that are not terminated by newline). This doesn't fit
+ * very well into libcfs_debug_msg() interface that assumes that each message
+ * supplied to it is a self-contained output line.
+ *
+ * To work around this, strings are collected in a temporary buffer
+ * (implemented as a value of lu_cdebug_key key), until terminating newline
+ * character is detected.
+ *
+ */
+
+enum {
+ /**
+ * Maximal line size.
+ *
+ * XXX overflow is not handled correctly.
+ */
+ LU_CDEBUG_LINE = 512
+};
+
+struct lu_cdebug_data {
+ /**
+ * Temporary buffer.
+ */
+ char lck_area[LU_CDEBUG_LINE];
+};
+
+/* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
+LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data);
+
+/**
+ * Key, holding temporary buffer. This key is registered very early by
+ * lu_global_init().
+ */
+struct lu_context_key lu_global_key = {
+ .lct_tags = LCT_MD_THREAD | LCT_DT_THREAD |
+ LCT_MG_THREAD | LCT_CL_THREAD | LCT_LOCAL,
+ .lct_init = lu_global_key_init,
+ .lct_fini = lu_global_key_fini
+};
+
+/**
+ * Printer function emitting messages through libcfs_debug_msg().
+ */
+int lu_cdebug_printer(const struct lu_env *env,
+ void *cookie, const char *format, ...)
+{
+ struct libcfs_debug_msg_data *msgdata = cookie;
+ struct lu_cdebug_data *key;
+ int used;
+ int complete;
+ va_list args;
+
+ va_start(args, format);
+
+ key = lu_context_key_get(&env->le_ctx, &lu_global_key);
+ LASSERT(key != NULL);
+
+ used = strlen(key->lck_area);
+ complete = format[strlen(format) - 1] == '\n';
+ /*
+ * Append new chunk to the buffer.
+ */
+ vsnprintf(key->lck_area + used,
+ ARRAY_SIZE(key->lck_area) - used, format, args);
+ if (complete) {
+ if (cfs_cdebug_show(msgdata->msg_mask, msgdata->msg_subsys))
+ libcfs_debug_msg(msgdata, "%s", key->lck_area);
+ key->lck_area[0] = 0;
+ }
+ va_end(args);
+ return 0;
+}
+EXPORT_SYMBOL(lu_cdebug_printer);
+
+/**
+ * Print object header.
+ */
+void lu_object_header_print(const struct lu_env *env, void *cookie,
+ lu_printer_t printer,
+ const struct lu_object_header *hdr)
+{
+ (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
+ hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
+ PFID(&hdr->loh_fid),
+ hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
+ list_empty((struct list_head *)&hdr->loh_lru) ? \
+ "" : " lru",
+ hdr->loh_attr & LOHA_EXISTS ? " exist":"");
+}
+EXPORT_SYMBOL(lu_object_header_print);
+
+/**
+ * Print human readable representation of the \a o to the \a printer.
+ */
+void lu_object_print(const struct lu_env *env, void *cookie,
+ lu_printer_t printer, const struct lu_object *o)
+{
+ static const char ruler[] = "........................................";
+ struct lu_object_header *top;
+ int depth = 4;
+
+ top = o->lo_header;
+ lu_object_header_print(env, cookie, printer, top);
+ (*printer)(env, cookie, "{\n");
+
+ list_for_each_entry(o, &top->loh_layers, lo_linkage) {
+ /*
+ * print `.' \a depth times followed by type name and address
+ */
+ (*printer)(env, cookie, "%*.*s%s@%p", depth, depth, ruler,
+ o->lo_dev->ld_type->ldt_name, o);
+
+ if (o->lo_ops->loo_object_print != NULL)
+ (*o->lo_ops->loo_object_print)(env, cookie, printer, o);
+
+ (*printer)(env, cookie, "\n");
+ }
+
+ (*printer)(env, cookie, "} header@%p\n", top);
+}
+EXPORT_SYMBOL(lu_object_print);
+
+/**
+ * Check object consistency.
+ */
+int lu_object_invariant(const struct lu_object *o)
+{
+ struct lu_object_header *top;
+
+ top = o->lo_header;
+ list_for_each_entry(o, &top->loh_layers, lo_linkage) {
+ if (o->lo_ops->loo_object_invariant != NULL &&
+ !o->lo_ops->loo_object_invariant(o))
+ return 0;
+ }
+ return 1;
+}
+EXPORT_SYMBOL(lu_object_invariant);
+
+static struct lu_object *htable_lookup(struct lu_site *s,
+ struct cfs_hash_bd *bd,
+ const struct lu_fid *f,
+ wait_queue_t *waiter,
+ __u64 *version)
+{
+ struct lu_site_bkt_data *bkt;
+ struct lu_object_header *h;
+ struct hlist_node *hnode;
+ __u64 ver = cfs_hash_bd_version_get(bd);
+
+ if (*version == ver)
+ return ERR_PTR(-ENOENT);
+
+ *version = ver;
+ bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, bd);
+ /* cfs_hash_bd_peek_locked is a somehow "internal" function
+ * of cfs_hash, it doesn't add refcount on object. */
+ hnode = cfs_hash_bd_peek_locked(s->ls_obj_hash, bd, (void *)f);
+ if (hnode == NULL) {
+ lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_MISS);
+ return ERR_PTR(-ENOENT);
+ }
+
+ h = container_of0(hnode, struct lu_object_header, loh_hash);
+ if (likely(!lu_object_is_dying(h))) {
+ cfs_hash_get(s->ls_obj_hash, hnode);
+ lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT);
+ list_del_init(&h->loh_lru);
+ return lu_object_top(h);
+ }
+
+ /*
+ * Lookup found an object being destroyed this object cannot be
+ * returned (to assure that references to dying objects are eventually
+ * drained), and moreover, lookup has to wait until object is freed.
+ */
+
+ init_waitqueue_entry(waiter, current);
+ add_wait_queue(&bkt->lsb_marche_funebre, waiter);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE);
+ return ERR_PTR(-EAGAIN);
+}
+
+/**
+ * Search cache for an object with the fid \a f. If such object is found,
+ * return it. Otherwise, create new object, insert it into cache and return
+ * it. In any case, additional reference is acquired on the returned object.
+ */
+struct lu_object *lu_object_find(const struct lu_env *env,
+ struct lu_device *dev, const struct lu_fid *f,
+ const struct lu_object_conf *conf)
+{
+ return lu_object_find_at(env, dev->ld_site->ls_top_dev, f, conf);
+}
+EXPORT_SYMBOL(lu_object_find);
+
+static struct lu_object *lu_object_new(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_fid *f,
+ const struct lu_object_conf *conf)
+{
+ struct lu_object *o;
+ struct cfs_hash *hs;
+ struct cfs_hash_bd bd;
+ struct lu_site_bkt_data *bkt;
+
+ o = lu_object_alloc(env, dev, f, conf);
+ if (unlikely(IS_ERR(o)))
+ return o;
+
+ hs = dev->ld_site->ls_obj_hash;
+ cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
+ bkt = cfs_hash_bd_extra_get(hs, &bd);
+ cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
+ bkt->lsb_busy++;
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ return o;
+}
+
+/**
+ * Core logic of lu_object_find*() functions.
+ */
+static struct lu_object *lu_object_find_try(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_fid *f,
+ const struct lu_object_conf *conf,
+ wait_queue_t *waiter)
+{
+ struct lu_object *o;
+ struct lu_object *shadow;
+ struct lu_site *s;
+ struct cfs_hash *hs;
+ struct cfs_hash_bd bd;
+ __u64 version = 0;
+
+ /*
+ * This uses standard index maintenance protocol:
+ *
+ * - search index under lock, and return object if found;
+ * - otherwise, unlock index, allocate new object;
+ * - lock index and search again;
+ * - if nothing is found (usual case), insert newly created
+ * object into index;
+ * - otherwise (race: other thread inserted object), free
+ * object just allocated.
+ * - unlock index;
+ * - return object.
+ *
+ * For "LOC_F_NEW" case, we are sure the object is new established.
+ * It is unnecessary to perform lookup-alloc-lookup-insert, instead,
+ * just alloc and insert directly.
+ *
+ * If dying object is found during index search, add @waiter to the
+ * site wait-queue and return ERR_PTR(-EAGAIN).
+ */
+ if (conf != NULL && conf->loc_flags & LOC_F_NEW)
+ return lu_object_new(env, dev, f, conf);
+
+ s = dev->ld_site;
+ hs = s->ls_obj_hash;
+ cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
+ o = htable_lookup(s, &bd, f, waiter, &version);
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ if (!IS_ERR(o) || PTR_ERR(o) != -ENOENT)
+ return o;
+
+ /*
+ * Allocate new object. This may result in rather complicated
+ * operations, including fld queries, inode loading, etc.
+ */
+ o = lu_object_alloc(env, dev, f, conf);
+ if (unlikely(IS_ERR(o)))
+ return o;
+
+ LASSERT(lu_fid_eq(lu_object_fid(o), f));
+
+ cfs_hash_bd_lock(hs, &bd, 1);
+
+ shadow = htable_lookup(s, &bd, f, waiter, &version);
+ if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) {
+ struct lu_site_bkt_data *bkt;
+
+ bkt = cfs_hash_bd_extra_get(hs, &bd);
+ cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
+ bkt->lsb_busy++;
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ return o;
+ }
+
+ lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_RACE);
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ lu_object_free(env, o);
+ return shadow;
+}
+
+/**
+ * Much like lu_object_find(), but top level device of object is specifically
+ * \a dev rather than top level device of the site. This interface allows
+ * objects of different "stacking" to be created within the same site.
+ */
+struct lu_object *lu_object_find_at(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_fid *f,
+ const struct lu_object_conf *conf)
+{
+ struct lu_site_bkt_data *bkt;
+ struct lu_object *obj;
+ wait_queue_t wait;
+
+ while (1) {
+ obj = lu_object_find_try(env, dev, f, conf, &wait);
+ if (obj != ERR_PTR(-EAGAIN))
+ return obj;
+ /*
+ * lu_object_find_try() already added waiter into the
+ * wait queue.
+ */
+ schedule();
+ bkt = lu_site_bkt_from_fid(dev->ld_site, (void *)f);
+ remove_wait_queue(&bkt->lsb_marche_funebre, &wait);
+ }
+}
+EXPORT_SYMBOL(lu_object_find_at);
+
+/**
+ * Find object with given fid, and return its slice belonging to given device.
+ */
+struct lu_object *lu_object_find_slice(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_fid *f,
+ const struct lu_object_conf *conf)
+{
+ struct lu_object *top;
+ struct lu_object *obj;
+
+ top = lu_object_find(env, dev, f, conf);
+ if (!IS_ERR(top)) {
+ obj = lu_object_locate(top->lo_header, dev->ld_type);
+ if (obj == NULL)
+ lu_object_put(env, top);
+ } else
+ obj = top;
+ return obj;
+}
+EXPORT_SYMBOL(lu_object_find_slice);
+
+/**
+ * Global list of all device types.
+ */
+static LIST_HEAD(lu_device_types);
+
+int lu_device_type_init(struct lu_device_type *ldt)
+{
+ int result = 0;
+
+ INIT_LIST_HEAD(&ldt->ldt_linkage);
+ if (ldt->ldt_ops->ldto_init)
+ result = ldt->ldt_ops->ldto_init(ldt);
+ if (result == 0)
+ list_add(&ldt->ldt_linkage, &lu_device_types);
+ return result;
+}
+EXPORT_SYMBOL(lu_device_type_init);
+
+void lu_device_type_fini(struct lu_device_type *ldt)
+{
+ list_del_init(&ldt->ldt_linkage);
+ if (ldt->ldt_ops->ldto_fini)
+ ldt->ldt_ops->ldto_fini(ldt);
+}
+EXPORT_SYMBOL(lu_device_type_fini);
+
+void lu_types_stop(void)
+{
+ struct lu_device_type *ldt;
+
+ list_for_each_entry(ldt, &lu_device_types, ldt_linkage) {
+ if (ldt->ldt_device_nr == 0 && ldt->ldt_ops->ldto_stop)
+ ldt->ldt_ops->ldto_stop(ldt);
+ }
+}
+EXPORT_SYMBOL(lu_types_stop);
+
+/**
+ * Global list of all sites on this node
+ */
+static LIST_HEAD(lu_sites);
+static DEFINE_MUTEX(lu_sites_guard);
+
+/**
+ * Global environment used by site shrinker.
+ */
+static struct lu_env lu_shrink_env;
+
+struct lu_site_print_arg {
+ struct lu_env *lsp_env;
+ void *lsp_cookie;
+ lu_printer_t lsp_printer;
+};
+
+static int
+lu_site_obj_print(struct cfs_hash *hs, struct cfs_hash_bd *bd,
+ struct hlist_node *hnode, void *data)
+{
+ struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
+ struct lu_object_header *h;
+
+ h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+ if (!list_empty(&h->loh_layers)) {
+ const struct lu_object *o;
+
+ o = lu_object_top(h);
+ lu_object_print(arg->lsp_env, arg->lsp_cookie,
+ arg->lsp_printer, o);
+ } else {
+ lu_object_header_print(arg->lsp_env, arg->lsp_cookie,
+ arg->lsp_printer, h);
+ }
+ return 0;
+}
+
+/**
+ * Print all objects in \a s.
+ */
+void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
+ lu_printer_t printer)
+{
+ struct lu_site_print_arg arg = {
+ .lsp_env = (struct lu_env *)env,
+ .lsp_cookie = cookie,
+ .lsp_printer = printer,
+ };
+
+ cfs_hash_for_each(s->ls_obj_hash, lu_site_obj_print, &arg);
+}
+EXPORT_SYMBOL(lu_site_print);
+
+enum {
+ LU_CACHE_PERCENT_MAX = 50,
+ LU_CACHE_PERCENT_DEFAULT = 20
+};
+
+static unsigned int lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
+module_param(lu_cache_percent, int, 0644);
+MODULE_PARM_DESC(lu_cache_percent, "Percentage of memory to be used as lu_object cache");
+
+/**
+ * Return desired hash table order.
+ */
+static int lu_htable_order(void)
+{
+ unsigned long cache_size;
+ int bits;
+
+ /*
+ * Calculate hash table size, assuming that we want reasonable
+ * performance when 20% of total memory is occupied by cache of
+ * lu_objects.
+ *
+ * Size of lu_object is (arbitrary) taken as 1K (together with inode).
+ */
+ cache_size = totalram_pages;
+
+#if BITS_PER_LONG == 32
+ /* limit hashtable size for lowmem systems to low RAM */
+ if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT))
+ cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4;
+#endif
+
+ /* clear off unreasonable cache setting. */
+ if (lu_cache_percent == 0 || lu_cache_percent > LU_CACHE_PERCENT_MAX) {
+ CWARN("obdclass: invalid lu_cache_percent: %u, it must be in the range of (0, %u]. Will use default value: %u.\n",
+ lu_cache_percent, LU_CACHE_PERCENT_MAX,
+ LU_CACHE_PERCENT_DEFAULT);
+
+ lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
+ }
+ cache_size = cache_size / 100 * lu_cache_percent *
+ (PAGE_CACHE_SIZE / 1024);
+
+ for (bits = 1; (1 << bits) < cache_size; ++bits) {
+ ;
+ }
+ return bits;
+}
+
+static unsigned lu_obj_hop_hash(struct cfs_hash *hs,
+ const void *key, unsigned mask)
+{
+ struct lu_fid *fid = (struct lu_fid *)key;
+ __u32 hash;
+
+ hash = fid_flatten32(fid);
+ hash += (hash >> 4) + (hash << 12); /* mixing oid and seq */
+ hash = hash_long(hash, hs->hs_bkt_bits);
+
+ /* give me another random factor */
+ hash -= hash_long((unsigned long)hs, fid_oid(fid) % 11 + 3);
+
+ hash <<= hs->hs_cur_bits - hs->hs_bkt_bits;
+ hash |= (fid_seq(fid) + fid_oid(fid)) & (CFS_HASH_NBKT(hs) - 1);
+
+ return hash & mask;
+}
+
+static void *lu_obj_hop_object(struct hlist_node *hnode)
+{
+ return hlist_entry(hnode, struct lu_object_header, loh_hash);
+}
+
+static void *lu_obj_hop_key(struct hlist_node *hnode)
+{
+ struct lu_object_header *h;
+
+ h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+ return &h->loh_fid;
+}
+
+static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode)
+{
+ struct lu_object_header *h;
+
+ h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+ return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key);
+}
+
+static void lu_obj_hop_get(struct cfs_hash *hs, struct hlist_node *hnode)
+{
+ struct lu_object_header *h;
+
+ h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+ if (atomic_add_return(1, &h->loh_ref) == 1) {
+ struct lu_site_bkt_data *bkt;
+ struct cfs_hash_bd bd;
+
+ cfs_hash_bd_get(hs, &h->loh_fid, &bd);
+ bkt = cfs_hash_bd_extra_get(hs, &bd);
+ bkt->lsb_busy++;
+ }
+}
+
+static void lu_obj_hop_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
+{
+ LBUG(); /* we should never called it */
+}
+
+cfs_hash_ops_t lu_site_hash_ops = {
+ .hs_hash = lu_obj_hop_hash,
+ .hs_key = lu_obj_hop_key,
+ .hs_keycmp = lu_obj_hop_keycmp,
+ .hs_object = lu_obj_hop_object,
+ .hs_get = lu_obj_hop_get,
+ .hs_put_locked = lu_obj_hop_put_locked,
+};
+
+void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d)
+{
+ spin_lock(&s->ls_ld_lock);
+ if (list_empty(&d->ld_linkage))
+ list_add(&d->ld_linkage, &s->ls_ld_linkage);
+ spin_unlock(&s->ls_ld_lock);
+}
+EXPORT_SYMBOL(lu_dev_add_linkage);
+
+void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d)
+{
+ spin_lock(&s->ls_ld_lock);
+ list_del_init(&d->ld_linkage);
+ spin_unlock(&s->ls_ld_lock);
+}
+EXPORT_SYMBOL(lu_dev_del_linkage);
+
+/**
+ * Initialize site \a s, with \a d as the top level device.
+ */
+#define LU_SITE_BITS_MIN 12
+#define LU_SITE_BITS_MAX 24
+/**
+ * total 256 buckets, we don't want too many buckets because:
+ * - consume too much memory
+ * - avoid unbalanced LRU list
+ */
+#define LU_SITE_BKT_BITS 8
+
+int lu_site_init(struct lu_site *s, struct lu_device *top)
+{
+ struct lu_site_bkt_data *bkt;
+ struct cfs_hash_bd bd;
+ char name[16];
+ int bits;
+ int i;
+
+ memset(s, 0, sizeof(*s));
+ bits = lu_htable_order();
+ snprintf(name, 16, "lu_site_%s", top->ld_type->ldt_name);
+ for (bits = min(max(LU_SITE_BITS_MIN, bits), LU_SITE_BITS_MAX);
+ bits >= LU_SITE_BITS_MIN; bits--) {
+ s->ls_obj_hash = cfs_hash_create(name, bits, bits,
+ bits - LU_SITE_BKT_BITS,
+ sizeof(*bkt), 0, 0,
+ &lu_site_hash_ops,
+ CFS_HASH_SPIN_BKTLOCK |
+ CFS_HASH_NO_ITEMREF |
+ CFS_HASH_DEPTH |
+ CFS_HASH_ASSERT_EMPTY);
+ if (s->ls_obj_hash != NULL)
+ break;
+ }
+
+ if (s->ls_obj_hash == NULL) {
+ CERROR("failed to create lu_site hash with bits: %d\n", bits);
+ return -ENOMEM;
+ }
+
+ cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
+ bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
+ INIT_LIST_HEAD(&bkt->lsb_lru);
+ init_waitqueue_head(&bkt->lsb_marche_funebre);
+ }
+
+ s->ls_stats = lprocfs_alloc_stats(LU_SS_LAST_STAT, 0);
+ if (s->ls_stats == NULL) {
+ cfs_hash_putref(s->ls_obj_hash);
+ s->ls_obj_hash = NULL;
+ return -ENOMEM;
+ }
+
+ lprocfs_counter_init(s->ls_stats, LU_SS_CREATED,
+ 0, "created", "created");
+ lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_HIT,
+ 0, "cache_hit", "cache_hit");
+ lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_MISS,
+ 0, "cache_miss", "cache_miss");
+ lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_RACE,
+ 0, "cache_race", "cache_race");
+ lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_DEATH_RACE,
+ 0, "cache_death_race", "cache_death_race");
+ lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
+ 0, "lru_purged", "lru_purged");
+
+ INIT_LIST_HEAD(&s->ls_linkage);
+ s->ls_top_dev = top;
+ top->ld_site = s;
+ lu_device_get(top);
+ lu_ref_add(&top->ld_reference, "site-top", s);
+
+ INIT_LIST_HEAD(&s->ls_ld_linkage);
+ spin_lock_init(&s->ls_ld_lock);
+
+ lu_dev_add_linkage(s, top);
+
+ return 0;
+}
+EXPORT_SYMBOL(lu_site_init);
+
+/**
+ * Finalize \a s and release its resources.
+ */
+void lu_site_fini(struct lu_site *s)
+{
+ mutex_lock(&lu_sites_guard);
+ list_del_init(&s->ls_linkage);
+ mutex_unlock(&lu_sites_guard);
+
+ if (s->ls_obj_hash != NULL) {
+ cfs_hash_putref(s->ls_obj_hash);
+ s->ls_obj_hash = NULL;
+ }
+
+ if (s->ls_top_dev != NULL) {
+ s->ls_top_dev->ld_site = NULL;
+ lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s);
+ lu_device_put(s->ls_top_dev);
+ s->ls_top_dev = NULL;
+ }
+
+ if (s->ls_stats != NULL)
+ lprocfs_free_stats(&s->ls_stats);
+}
+EXPORT_SYMBOL(lu_site_fini);
+
+/**
+ * Called when initialization of stack for this site is completed.
+ */
+int lu_site_init_finish(struct lu_site *s)
+{
+ int result;
+ mutex_lock(&lu_sites_guard);
+ result = lu_context_refill(&lu_shrink_env.le_ctx);
+ if (result == 0)
+ list_add(&s->ls_linkage, &lu_sites);
+ mutex_unlock(&lu_sites_guard);
+ return result;
+}
+EXPORT_SYMBOL(lu_site_init_finish);
+
+/**
+ * Acquire additional reference on device \a d
+ */
+void lu_device_get(struct lu_device *d)
+{
+ atomic_inc(&d->ld_ref);
+}
+EXPORT_SYMBOL(lu_device_get);
+
+/**
+ * Release reference on device \a d.
+ */
+void lu_device_put(struct lu_device *d)
+{
+ LASSERT(atomic_read(&d->ld_ref) > 0);
+ atomic_dec(&d->ld_ref);
+}
+EXPORT_SYMBOL(lu_device_put);
+
+/**
+ * Initialize device \a d of type \a t.
+ */
+int lu_device_init(struct lu_device *d, struct lu_device_type *t)
+{
+ if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start != NULL)
+ t->ldt_ops->ldto_start(t);
+ memset(d, 0, sizeof(*d));
+ atomic_set(&d->ld_ref, 0);
+ d->ld_type = t;
+ lu_ref_init(&d->ld_reference);
+ INIT_LIST_HEAD(&d->ld_linkage);
+ return 0;
+}
+EXPORT_SYMBOL(lu_device_init);
+
+/**
+ * Finalize device \a d.
+ */
+void lu_device_fini(struct lu_device *d)
+{
+ struct lu_device_type *t;
+
+ t = d->ld_type;
+ if (d->ld_obd != NULL) {
+ d->ld_obd->obd_lu_dev = NULL;
+ d->ld_obd = NULL;
+ }
+
+ lu_ref_fini(&d->ld_reference);
+ LASSERTF(atomic_read(&d->ld_ref) == 0,
+ "Refcount is %u\n", atomic_read(&d->ld_ref));
+ LASSERT(t->ldt_device_nr > 0);
+ if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop != NULL)
+ t->ldt_ops->ldto_stop(t);
+}
+EXPORT_SYMBOL(lu_device_fini);
+
+/**
+ * Initialize object \a o that is part of compound object \a h and was created
+ * by device \a d.
+ */
+int lu_object_init(struct lu_object *o, struct lu_object_header *h,
+ struct lu_device *d)
+{
+ memset(o, 0, sizeof(*o));
+ o->lo_header = h;
+ o->lo_dev = d;
+ lu_device_get(d);
+ lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o);
+ INIT_LIST_HEAD(&o->lo_linkage);
+
+ return 0;
+}
+EXPORT_SYMBOL(lu_object_init);
+
+/**
+ * Finalize object and release its resources.
+ */
+void lu_object_fini(struct lu_object *o)
+{
+ struct lu_device *dev = o->lo_dev;
+
+ LASSERT(list_empty(&o->lo_linkage));
+
+ if (dev != NULL) {
+ lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref,
+ "lu_object", o);
+ lu_device_put(dev);
+ o->lo_dev = NULL;
+ }
+}
+EXPORT_SYMBOL(lu_object_fini);
+
+/**
+ * Add object \a o as first layer of compound object \a h
+ *
+ * This is typically called by the ->ldo_object_alloc() method of top-level
+ * device.
+ */
+void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
+{
+ list_move(&o->lo_linkage, &h->loh_layers);
+}
+EXPORT_SYMBOL(lu_object_add_top);
+
+/**
+ * Add object \a o as a layer of compound object, going after \a before.
+ *
+ * This is typically called by the ->ldo_object_alloc() method of \a
+ * before->lo_dev.
+ */
+void lu_object_add(struct lu_object *before, struct lu_object *o)
+{
+ list_move(&o->lo_linkage, &before->lo_linkage);
+}
+EXPORT_SYMBOL(lu_object_add);
+
+/**
+ * Initialize compound object.
+ */
+int lu_object_header_init(struct lu_object_header *h)
+{
+ memset(h, 0, sizeof(*h));
+ atomic_set(&h->loh_ref, 1);
+ INIT_HLIST_NODE(&h->loh_hash);
+ INIT_LIST_HEAD(&h->loh_lru);
+ INIT_LIST_HEAD(&h->loh_layers);
+ lu_ref_init(&h->loh_reference);
+ return 0;
+}
+EXPORT_SYMBOL(lu_object_header_init);
+
+/**
+ * Finalize compound object.
+ */
+void lu_object_header_fini(struct lu_object_header *h)
+{
+ LASSERT(list_empty(&h->loh_layers));
+ LASSERT(list_empty(&h->loh_lru));
+ LASSERT(hlist_unhashed(&h->loh_hash));
+ lu_ref_fini(&h->loh_reference);
+}
+EXPORT_SYMBOL(lu_object_header_fini);
+
+/**
+ * Given a compound object, find its slice, corresponding to the device type
+ * \a dtype.
+ */
+struct lu_object *lu_object_locate(struct lu_object_header *h,
+ const struct lu_device_type *dtype)
+{
+ struct lu_object *o;
+
+ list_for_each_entry(o, &h->loh_layers, lo_linkage) {
+ if (o->lo_dev->ld_type == dtype)
+ return o;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(lu_object_locate);
+
+
+
+/**
+ * Finalize and free devices in the device stack.
+ *
+ * Finalize device stack by purging object cache, and calling
+ * lu_device_type_operations::ldto_device_fini() and
+ * lu_device_type_operations::ldto_device_free() on all devices in the stack.
+ */
+void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
+{
+ struct lu_site *site = top->ld_site;
+ struct lu_device *scan;
+ struct lu_device *next;
+
+ lu_site_purge(env, site, ~0);
+ for (scan = top; scan != NULL; scan = next) {
+ next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan);
+ lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init);
+ lu_device_put(scan);
+ }
+
+ /* purge again. */
+ lu_site_purge(env, site, ~0);
+
+ for (scan = top; scan != NULL; scan = next) {
+ const struct lu_device_type *ldt = scan->ld_type;
+ struct obd_type *type;
+
+ next = ldt->ldt_ops->ldto_device_free(env, scan);
+ type = ldt->ldt_obd_type;
+ if (type != NULL) {
+ type->typ_refcnt--;
+ class_put_type(type);
+ }
+ }
+}
+EXPORT_SYMBOL(lu_stack_fini);
+
+enum {
+ /**
+ * Maximal number of tld slots.
+ */
+ LU_CONTEXT_KEY_NR = 40
+};
+
+static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
+
+static DEFINE_SPINLOCK(lu_keys_guard);
+
+/**
+ * Global counter incremented whenever key is registered, unregistered,
+ * revived or quiesced. This is used to void unnecessary calls to
+ * lu_context_refill(). No locking is provided, as initialization and shutdown
+ * are supposed to be externally serialized.
+ */
+static unsigned key_set_version;
+
+/**
+ * Register new key.
+ */
+int lu_context_key_register(struct lu_context_key *key)
+{
+ int result;
+ int i;
+
+ LASSERT(key->lct_init != NULL);
+ LASSERT(key->lct_fini != NULL);
+ LASSERT(key->lct_tags != 0);
+
+ result = -ENFILE;
+ spin_lock(&lu_keys_guard);
+ for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
+ if (lu_keys[i] == NULL) {
+ key->lct_index = i;
+ atomic_set(&key->lct_used, 1);
+ lu_keys[i] = key;
+ lu_ref_init(&key->lct_reference);
+ result = 0;
+ ++key_set_version;
+ break;
+ }
+ }
+ spin_unlock(&lu_keys_guard);
+ return result;
+}
+EXPORT_SYMBOL(lu_context_key_register);
+
+static void key_fini(struct lu_context *ctx, int index)
+{
+ if (ctx->lc_value != NULL && ctx->lc_value[index] != NULL) {
+ struct lu_context_key *key;
+
+ key = lu_keys[index];
+ LASSERT(key != NULL);
+ LASSERT(key->lct_fini != NULL);
+ LASSERT(atomic_read(&key->lct_used) > 1);
+
+ key->lct_fini(ctx, key, ctx->lc_value[index]);
+ lu_ref_del(&key->lct_reference, "ctx", ctx);
+ atomic_dec(&key->lct_used);
+
+ if ((ctx->lc_tags & LCT_NOREF) == 0) {
+#ifdef CONFIG_MODULE_UNLOAD
+ LINVRNT(module_refcount(key->lct_owner) > 0);
+#endif
+ module_put(key->lct_owner);
+ }
+ ctx->lc_value[index] = NULL;
+ }
+}
+
+/**
+ * Deregister key.
+ */
+void lu_context_key_degister(struct lu_context_key *key)
+{
+ LASSERT(atomic_read(&key->lct_used) >= 1);
+ LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
+
+ lu_context_key_quiesce(key);
+
+ ++key_set_version;
+ spin_lock(&lu_keys_guard);
+ key_fini(&lu_shrink_env.le_ctx, key->lct_index);
+ if (lu_keys[key->lct_index]) {
+ lu_keys[key->lct_index] = NULL;
+ lu_ref_fini(&key->lct_reference);
+ }
+ spin_unlock(&lu_keys_guard);
+
+ LASSERTF(atomic_read(&key->lct_used) == 1,
+ "key has instances: %d\n",
+ atomic_read(&key->lct_used));
+}
+EXPORT_SYMBOL(lu_context_key_degister);
+
+/**
+ * Register a number of keys. This has to be called after all keys have been
+ * initialized by a call to LU_CONTEXT_KEY_INIT().
+ */
+int lu_context_key_register_many(struct lu_context_key *k, ...)
+{
+ struct lu_context_key *key = k;
+ va_list args;
+ int result;
+
+ va_start(args, k);
+ do {
+ result = lu_context_key_register(key);
+ if (result)
+ break;
+ key = va_arg(args, struct lu_context_key *);
+ } while (key != NULL);
+ va_end(args);
+
+ if (result != 0) {
+ va_start(args, k);
+ while (k != key) {
+ lu_context_key_degister(k);
+ k = va_arg(args, struct lu_context_key *);
+ }
+ va_end(args);
+ }
+
+ return result;
+}
+EXPORT_SYMBOL(lu_context_key_register_many);
+
+/**
+ * De-register a number of keys. This is a dual to
+ * lu_context_key_register_many().
+ */
+void lu_context_key_degister_many(struct lu_context_key *k, ...)
+{
+ va_list args;
+
+ va_start(args, k);
+ do {
+ lu_context_key_degister(k);
+ k = va_arg(args, struct lu_context_key*);
+ } while (k != NULL);
+ va_end(args);
+}
+EXPORT_SYMBOL(lu_context_key_degister_many);
+
+/**
+ * Revive a number of keys.
+ */
+void lu_context_key_revive_many(struct lu_context_key *k, ...)
+{
+ va_list args;
+
+ va_start(args, k);
+ do {
+ lu_context_key_revive(k);
+ k = va_arg(args, struct lu_context_key*);
+ } while (k != NULL);
+ va_end(args);
+}
+EXPORT_SYMBOL(lu_context_key_revive_many);
+
+/**
+ * Quiescent a number of keys.
+ */
+void lu_context_key_quiesce_many(struct lu_context_key *k, ...)
+{
+ va_list args;
+
+ va_start(args, k);
+ do {
+ lu_context_key_quiesce(k);
+ k = va_arg(args, struct lu_context_key*);
+ } while (k != NULL);
+ va_end(args);
+}
+EXPORT_SYMBOL(lu_context_key_quiesce_many);
+
+/**
+ * Return value associated with key \a key in context \a ctx.
+ */
+void *lu_context_key_get(const struct lu_context *ctx,
+ const struct lu_context_key *key)
+{
+ LINVRNT(ctx->lc_state == LCS_ENTERED);
+ LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
+ LASSERT(lu_keys[key->lct_index] == key);
+ return ctx->lc_value[key->lct_index];
+}
+EXPORT_SYMBOL(lu_context_key_get);
+
+/**
+ * List of remembered contexts. XXX document me.
+ */
+static LIST_HEAD(lu_context_remembered);
+
+/**
+ * Destroy \a key in all remembered contexts. This is used to destroy key
+ * values in "shared" contexts (like service threads), when a module owning
+ * the key is about to be unloaded.
+ */
+void lu_context_key_quiesce(struct lu_context_key *key)
+{
+ struct lu_context *ctx;
+
+ if (!(key->lct_tags & LCT_QUIESCENT)) {
+ /*
+ * XXX layering violation.
+ */
+ key->lct_tags |= LCT_QUIESCENT;
+ /*
+ * XXX memory barrier has to go here.
+ */
+ spin_lock(&lu_keys_guard);
+ list_for_each_entry(ctx, &lu_context_remembered,
+ lc_remember)
+ key_fini(ctx, key->lct_index);
+ spin_unlock(&lu_keys_guard);
+ ++key_set_version;
+ }
+}
+EXPORT_SYMBOL(lu_context_key_quiesce);
+
+void lu_context_key_revive(struct lu_context_key *key)
+{
+ key->lct_tags &= ~LCT_QUIESCENT;
+ ++key_set_version;
+}
+EXPORT_SYMBOL(lu_context_key_revive);
+
+static void keys_fini(struct lu_context *ctx)
+{
+ int i;
+
+ if (ctx->lc_value == NULL)
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(lu_keys); ++i)
+ key_fini(ctx, i);
+
+ OBD_FREE(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0]));
+ ctx->lc_value = NULL;
+}
+
+static int keys_fill(struct lu_context *ctx)
+{
+ int i;
+
+ LINVRNT(ctx->lc_value != NULL);
+ for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
+ struct lu_context_key *key;
+
+ key = lu_keys[i];
+ if (ctx->lc_value[i] == NULL && key != NULL &&
+ (key->lct_tags & ctx->lc_tags) &&
+ /*
+ * Don't create values for a LCT_QUIESCENT key, as this
+ * will pin module owning a key.
+ */
+ !(key->lct_tags & LCT_QUIESCENT)) {
+ void *value;
+
+ LINVRNT(key->lct_init != NULL);
+ LINVRNT(key->lct_index == i);
+
+ value = key->lct_init(ctx, key);
+ if (unlikely(IS_ERR(value)))
+ return PTR_ERR(value);
+
+ if (!(ctx->lc_tags & LCT_NOREF))
+ try_module_get(key->lct_owner);
+ lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
+ atomic_inc(&key->lct_used);
+ /*
+ * This is the only place in the code, where an
+ * element of ctx->lc_value[] array is set to non-NULL
+ * value.
+ */
+ ctx->lc_value[i] = value;
+ if (key->lct_exit != NULL)
+ ctx->lc_tags |= LCT_HAS_EXIT;
+ }
+ ctx->lc_version = key_set_version;
+ }
+ return 0;
+}
+
+static int keys_init(struct lu_context *ctx)
+{
+ OBD_ALLOC(ctx->lc_value,
+ ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0]));
+ if (likely(ctx->lc_value != NULL))
+ return keys_fill(ctx);
+
+ return -ENOMEM;
+}
+
+/**
+ * Initialize context data-structure. Create values for all keys.
+ */
+int lu_context_init(struct lu_context *ctx, __u32 tags)
+{
+ int rc;
+
+ memset(ctx, 0, sizeof(*ctx));
+ ctx->lc_state = LCS_INITIALIZED;
+ ctx->lc_tags = tags;
+ if (tags & LCT_REMEMBER) {
+ spin_lock(&lu_keys_guard);
+ list_add(&ctx->lc_remember, &lu_context_remembered);
+ spin_unlock(&lu_keys_guard);
+ } else {
+ INIT_LIST_HEAD(&ctx->lc_remember);
+ }
+
+ rc = keys_init(ctx);
+ if (rc != 0)
+ lu_context_fini(ctx);
+
+ return rc;
+}
+EXPORT_SYMBOL(lu_context_init);
+
+/**
+ * Finalize context data-structure. Destroy key values.
+ */
+void lu_context_fini(struct lu_context *ctx)
+{
+ LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
+ ctx->lc_state = LCS_FINALIZED;
+
+ if ((ctx->lc_tags & LCT_REMEMBER) == 0) {
+ LASSERT(list_empty(&ctx->lc_remember));
+ keys_fini(ctx);
+
+ } else { /* could race with key degister */
+ spin_lock(&lu_keys_guard);
+ keys_fini(ctx);
+ list_del_init(&ctx->lc_remember);
+ spin_unlock(&lu_keys_guard);
+ }
+}
+EXPORT_SYMBOL(lu_context_fini);
+
+/**
+ * Called before entering context.
+ */
+void lu_context_enter(struct lu_context *ctx)
+{
+ LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
+ ctx->lc_state = LCS_ENTERED;
+}
+EXPORT_SYMBOL(lu_context_enter);
+
+/**
+ * Called after exiting from \a ctx
+ */
+void lu_context_exit(struct lu_context *ctx)
+{
+ int i;
+
+ LINVRNT(ctx->lc_state == LCS_ENTERED);
+ ctx->lc_state = LCS_LEFT;
+ if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
+ for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
+ if (ctx->lc_value[i] != NULL) {
+ struct lu_context_key *key;
+
+ key = lu_keys[i];
+ LASSERT(key != NULL);
+ if (key->lct_exit != NULL)
+ key->lct_exit(ctx,
+ key, ctx->lc_value[i]);
+ }
+ }
+ }
+}
+EXPORT_SYMBOL(lu_context_exit);
+
+/**
+ * Allocate for context all missing keys that were registered after context
+ * creation. key_set_version is only changed in rare cases when modules
+ * are loaded and removed.
+ */
+int lu_context_refill(struct lu_context *ctx)
+{
+ return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);
+}
+EXPORT_SYMBOL(lu_context_refill);
+
+/**
+ * lu_ctx_tags/lu_ses_tags will be updated if there are new types of
+ * obd being added. Currently, this is only used on client side, specifically
+ * for echo device client, for other stack (like ptlrpc threads), context are
+ * predefined when the lu_device type are registered, during the module probe
+ * phase.
+ */
+__u32 lu_context_tags_default = 0;
+__u32 lu_session_tags_default = 0;
+
+void lu_context_tags_update(__u32 tags)
+{
+ spin_lock(&lu_keys_guard);
+ lu_context_tags_default |= tags;
+ key_set_version++;
+ spin_unlock(&lu_keys_guard);
+}
+EXPORT_SYMBOL(lu_context_tags_update);
+
+void lu_context_tags_clear(__u32 tags)
+{
+ spin_lock(&lu_keys_guard);
+ lu_context_tags_default &= ~tags;
+ key_set_version++;
+ spin_unlock(&lu_keys_guard);
+}
+EXPORT_SYMBOL(lu_context_tags_clear);
+
+void lu_session_tags_update(__u32 tags)
+{
+ spin_lock(&lu_keys_guard);
+ lu_session_tags_default |= tags;
+ key_set_version++;
+ spin_unlock(&lu_keys_guard);
+}
+EXPORT_SYMBOL(lu_session_tags_update);
+
+void lu_session_tags_clear(__u32 tags)
+{
+ spin_lock(&lu_keys_guard);
+ lu_session_tags_default &= ~tags;
+ key_set_version++;
+ spin_unlock(&lu_keys_guard);
+}
+EXPORT_SYMBOL(lu_session_tags_clear);
+
+int lu_env_init(struct lu_env *env, __u32 tags)
+{
+ int result;
+
+ env->le_ses = NULL;
+ result = lu_context_init(&env->le_ctx, tags);
+ if (likely(result == 0))
+ lu_context_enter(&env->le_ctx);
+ return result;
+}
+EXPORT_SYMBOL(lu_env_init);
+
+void lu_env_fini(struct lu_env *env)
+{
+ lu_context_exit(&env->le_ctx);
+ lu_context_fini(&env->le_ctx);
+ env->le_ses = NULL;
+}
+EXPORT_SYMBOL(lu_env_fini);
+
+int lu_env_refill(struct lu_env *env)
+{
+ int result;
+
+ result = lu_context_refill(&env->le_ctx);
+ if (result == 0 && env->le_ses != NULL)
+ result = lu_context_refill(env->le_ses);
+ return result;
+}
+EXPORT_SYMBOL(lu_env_refill);
+
+/**
+ * Currently, this API will only be used by echo client.
+ * Because echo client and normal lustre client will share
+ * same cl_env cache. So echo client needs to refresh
+ * the env context after it get one from the cache, especially
+ * when normal client and echo client co-exist in the same client.
+ */
+int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags,
+ __u32 stags)
+{
+ if ((env->le_ctx.lc_tags & ctags) != ctags) {
+ env->le_ctx.lc_version = 0;
+ env->le_ctx.lc_tags |= ctags;
+ }
+
+ if (env->le_ses && (env->le_ses->lc_tags & stags) != stags) {
+ env->le_ses->lc_version = 0;
+ env->le_ses->lc_tags |= stags;
+ }
+
+ return lu_env_refill(env);
+}
+EXPORT_SYMBOL(lu_env_refill_by_tags);
+
+
+typedef struct lu_site_stats{
+ unsigned lss_populated;
+ unsigned lss_max_search;
+ unsigned lss_total;
+ unsigned lss_busy;
+} lu_site_stats_t;
+
+static void lu_site_stats_get(struct cfs_hash *hs,
+ lu_site_stats_t *stats, int populated)
+{
+ struct cfs_hash_bd bd;
+ int i;
+
+ cfs_hash_for_each_bucket(hs, &bd, i) {
+ struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd);
+ struct hlist_head *hhead;
+
+ cfs_hash_bd_lock(hs, &bd, 1);
+ stats->lss_busy += bkt->lsb_busy;
+ stats->lss_total += cfs_hash_bd_count_get(&bd);
+ stats->lss_max_search = max((int)stats->lss_max_search,
+ cfs_hash_bd_depmax_get(&bd));
+ if (!populated) {
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ continue;
+ }
+
+ cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
+ if (!hlist_empty(hhead))
+ stats->lss_populated++;
+ }
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ }
+}
+
+
+/*
+ * There exists a potential lock inversion deadlock scenario when using
+ * Lustre on top of ZFS. This occurs between one of ZFS's
+ * buf_hash_table.ht_lock's, and Lustre's lu_sites_guard lock. Essentially,
+ * thread A will take the lu_sites_guard lock and sleep on the ht_lock,
+ * while thread B will take the ht_lock and sleep on the lu_sites_guard
+ * lock. Obviously neither thread will wake and drop their respective hold
+ * on their lock.
+ *
+ * To prevent this from happening we must ensure the lu_sites_guard lock is
+ * not taken while down this code path. ZFS reliably does not set the
+ * __GFP_FS bit in its code paths, so this can be used to determine if it
+ * is safe to take the lu_sites_guard lock.
+ *
+ * Ideally we should accurately return the remaining number of cached
+ * objects without taking the lu_sites_guard lock, but this is not
+ * possible in the current implementation.
+ */
+static unsigned long lu_cache_shrink_count(struct shrinker *sk,
+ struct shrink_control *sc)
+{
+ lu_site_stats_t stats;
+ struct lu_site *s;
+ struct lu_site *tmp;
+ unsigned long cached = 0;
+
+ if (!(sc->gfp_mask & __GFP_FS))
+ return 0;
+
+ mutex_lock(&lu_sites_guard);
+ list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
+ memset(&stats, 0, sizeof(stats));
+ lu_site_stats_get(s->ls_obj_hash, &stats, 0);
+ cached += stats.lss_total - stats.lss_busy;
+ }
+ mutex_unlock(&lu_sites_guard);
+
+ cached = (cached / 100) * sysctl_vfs_cache_pressure;
+ CDEBUG(D_INODE, "%ld objects cached\n", cached);
+ return cached;
+}
+
+static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
+ struct shrink_control *sc)
+{
+ struct lu_site *s;
+ struct lu_site *tmp;
+ unsigned long remain = sc->nr_to_scan, freed = 0;
+ LIST_HEAD(splice);
+
+ if (!(sc->gfp_mask & __GFP_FS))
+ /* We must not take the lu_sites_guard lock when
+ * __GFP_FS is *not* set because of the deadlock
+ * possibility detailed above. Additionally,
+ * since we cannot determine the number of
+ * objects in the cache without taking this
+ * lock, we're in a particularly tough spot. As
+ * a result, we'll just lie and say our cache is
+ * empty. This _should_ be ok, as we can't
+ * reclaim objects when __GFP_FS is *not* set
+ * anyways.
+ */
+ return SHRINK_STOP;
+
+ mutex_lock(&lu_sites_guard);
+ list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
+ freed = lu_site_purge(&lu_shrink_env, s, remain);
+ remain -= freed;
+ /*
+ * Move just shrunk site to the tail of site list to
+ * assure shrinking fairness.
+ */
+ list_move_tail(&s->ls_linkage, &splice);
+ }
+ list_splice(&splice, lu_sites.prev);
+ mutex_unlock(&lu_sites_guard);
+
+ return sc->nr_to_scan - remain;
+}
+
+/*
+ * Debugging stuff.
+ */
+
+/**
+ * Environment to be used in debugger, contains all tags.
+ */
+struct lu_env lu_debugging_env;
+
+/**
+ * Debugging printer function using printk().
+ */
+int lu_printk_printer(const struct lu_env *env,
+ void *unused, const char *format, ...)
+{
+ va_list args;
+
+ va_start(args, format);
+ vprintk(format, args);
+ va_end(args);
+ return 0;
+}
+
+static struct shrinker lu_site_shrinker = {
+ .count_objects = lu_cache_shrink_count,
+ .scan_objects = lu_cache_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
+
+/**
+ * Initialization of global lu_* data.
+ */
+int lu_global_init(void)
+{
+ int result;
+
+ CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys);
+
+ result = lu_ref_global_init();
+ if (result != 0)
+ return result;
+
+ LU_CONTEXT_KEY_INIT(&lu_global_key);
+ result = lu_context_key_register(&lu_global_key);
+ if (result != 0)
+ return result;
+
+ /*
+ * At this level, we don't know what tags are needed, so allocate them
+ * conservatively. This should not be too bad, because this
+ * environment is global.
+ */
+ mutex_lock(&lu_sites_guard);
+ result = lu_env_init(&lu_shrink_env, LCT_SHRINKER);
+ mutex_unlock(&lu_sites_guard);
+ if (result != 0)
+ return result;
+
+ /*
+ * seeks estimation: 3 seeks to read a record from oi, one to read
+ * inode, one for ea. Unfortunately setting this high value results in
+ * lu_object/inode cache consuming all the memory.
+ */
+ register_shrinker(&lu_site_shrinker);
+
+ return result;
+}
+
+/**
+ * Dual to lu_global_init().
+ */
+void lu_global_fini(void)
+{
+ unregister_shrinker(&lu_site_shrinker);
+ lu_context_key_degister(&lu_global_key);
+
+ /*
+ * Tear shrinker environment down _after_ de-registering
+ * lu_global_key, because the latter has a value in the former.
+ */
+ mutex_lock(&lu_sites_guard);
+ lu_env_fini(&lu_shrink_env);
+ mutex_unlock(&lu_sites_guard);
+
+ lu_ref_global_fini();
+}
+
+static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
+{
+#if defined (CONFIG_PROC_FS)
+ struct lprocfs_counter ret;
+
+ lprocfs_stats_collect(stats, idx, &ret);
+ return (__u32)ret.lc_count;
+#else
+ return 0;
+#endif
+}
+
+/**
+ * Output site statistical counters into a buffer. Suitable for
+ * lprocfs_rd_*()-style functions.
+ */
+int lu_site_stats_print(const struct lu_site *s, struct seq_file *m)
+{
+ lu_site_stats_t stats;
+
+ memset(&stats, 0, sizeof(stats));
+ lu_site_stats_get(s->ls_obj_hash, &stats, 1);
+
+ seq_printf(m, "%d/%d %d/%d %d %d %d %d %d %d %d\n",
+ stats.lss_busy,
+ stats.lss_total,
+ stats.lss_populated,
+ CFS_HASH_NHLIST(s->ls_obj_hash),
+ stats.lss_max_search,
+ ls_stats_read(s->ls_stats, LU_SS_CREATED),
+ ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
+ ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
+ ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
+ ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
+ ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
+ return 0;
+}
+EXPORT_SYMBOL(lu_site_stats_print);
+
+/**
+ * Helper function to initialize a number of kmem slab caches at once.
+ */
+int lu_kmem_init(struct lu_kmem_descr *caches)
+{
+ int result;
+ struct lu_kmem_descr *iter = caches;
+
+ for (result = 0; iter->ckd_cache != NULL; ++iter) {
+ *iter->ckd_cache = kmem_cache_create(iter->ckd_name,
+ iter->ckd_size,
+ 0, 0, NULL);
+ if (*iter->ckd_cache == NULL) {
+ result = -ENOMEM;
+ /* free all previously allocated caches */
+ lu_kmem_fini(caches);
+ break;
+ }
+ }
+ return result;
+}
+EXPORT_SYMBOL(lu_kmem_init);
+
+/**
+ * Helper function to finalize a number of kmem slab cached at once. Dual to
+ * lu_kmem_init().
+ */
+void lu_kmem_fini(struct lu_kmem_descr *caches)
+{
+ for (; caches->ckd_cache != NULL; ++caches) {
+ if (*caches->ckd_cache != NULL) {
+ kmem_cache_destroy(*caches->ckd_cache);
+ *caches->ckd_cache = NULL;
+ }
+ }
+}
+EXPORT_SYMBOL(lu_kmem_fini);
+
+/**
+ * Temporary solution to be able to assign fid in ->do_create()
+ * till we have fully-functional OST fids
+ */
+void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
+ const struct lu_fid *fid)
+{
+ struct lu_site *s = o->lo_dev->ld_site;
+ struct lu_fid *old = &o->lo_header->loh_fid;
+ struct lu_site_bkt_data *bkt;
+ struct lu_object *shadow;
+ wait_queue_t waiter;
+ struct cfs_hash *hs;
+ struct cfs_hash_bd bd;
+ __u64 version = 0;
+
+ LASSERT(fid_is_zero(old));
+
+ hs = s->ls_obj_hash;
+ cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1);
+ shadow = htable_lookup(s, &bd, fid, &waiter, &version);
+ /* supposed to be unique */
+ LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
+ *old = *fid;
+ bkt = cfs_hash_bd_extra_get(hs, &bd);
+ cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
+ bkt->lsb_busy++;
+ cfs_hash_bd_unlock(hs, &bd, 1);
+}
+EXPORT_SYMBOL(lu_object_assign_fid);
+
+/**
+ * allocates object with 0 (non-assigned) fid
+ * XXX: temporary solution to be able to assign fid in ->do_create()
+ * till we have fully-functional OST fids
+ */
+struct lu_object *lu_object_anon(const struct lu_env *env,
+ struct lu_device *dev,
+ const struct lu_object_conf *conf)
+{
+ struct lu_fid fid;
+ struct lu_object *o;
+
+ fid_zero(&fid);
+ o = lu_object_alloc(env, dev, &fid, conf);
+
+ return o;
+}
+EXPORT_SYMBOL(lu_object_anon);
+
+struct lu_buf LU_BUF_NULL = {
+ .lb_buf = NULL,
+ .lb_len = 0
+};
+EXPORT_SYMBOL(LU_BUF_NULL);
+
+void lu_buf_free(struct lu_buf *buf)
+{
+ LASSERT(buf);
+ if (buf->lb_buf) {
+ LASSERT(buf->lb_len > 0);
+ OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
+ buf->lb_buf = NULL;
+ buf->lb_len = 0;
+ }
+}
+EXPORT_SYMBOL(lu_buf_free);
+
+void lu_buf_alloc(struct lu_buf *buf, int size)
+{
+ LASSERT(buf);
+ LASSERT(buf->lb_buf == NULL);
+ LASSERT(buf->lb_len == 0);
+ OBD_ALLOC_LARGE(buf->lb_buf, size);
+ if (likely(buf->lb_buf))
+ buf->lb_len = size;
+}
+EXPORT_SYMBOL(lu_buf_alloc);
+
+void lu_buf_realloc(struct lu_buf *buf, int size)
+{
+ lu_buf_free(buf);
+ lu_buf_alloc(buf, size);
+}
+EXPORT_SYMBOL(lu_buf_realloc);
+
+struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len)
+{
+ if (buf->lb_buf == NULL && buf->lb_len == 0)
+ lu_buf_alloc(buf, len);
+
+ if ((len > buf->lb_len) && (buf->lb_buf != NULL))
+ lu_buf_realloc(buf, len);
+
+ return buf;
+}
+EXPORT_SYMBOL(lu_buf_check_and_alloc);
+
+/**
+ * Increase the size of the \a buf.
+ * preserves old data in buffer
+ * old buffer remains unchanged on error
+ * \retval 0 or -ENOMEM
+ */
+int lu_buf_check_and_grow(struct lu_buf *buf, int len)
+{
+ char *ptr;
+
+ if (len <= buf->lb_len)
+ return 0;
+
+ OBD_ALLOC_LARGE(ptr, len);
+ if (ptr == NULL)
+ return -ENOMEM;
+
+ /* Free the old buf */
+ if (buf->lb_buf != NULL) {
+ memcpy(ptr, buf->lb_buf, buf->lb_len);
+ OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
+ }
+
+ buf->lb_buf = ptr;
+ buf->lb_len = len;
+ return 0;
+}
+EXPORT_SYMBOL(lu_buf_check_and_grow);
Code Review / kvmfornfv.git / blobdiff