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LU-6049 obdclass: Add synchro in lu_context_key_degister()
[fs/lustre-release.git] / lustre / obdclass / lu_object.c
index 86ccdc4..1ce045d 100644 (file)
@@ -27,7 +27,7 @@
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2013, Intel Corporation.
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #define DEBUG_SUBSYSTEM S_CLASS
 
 #include <libcfs/libcfs.h>
-
-#ifdef __KERNEL__
-# include <linux/module.h>
-#endif
-
-/* hash_long() */
-#include <libcfs/libcfs_hash.h>
+#include <linux/module.h>
+#include <libcfs/libcfs_hash.h> /* hash_long() */
 #include <obd_class.h>
 #include <obd_support.h>
 #include <lustre_disk.h>
@@ -60,8 +55,6 @@
 #include <lu_ref.h>
 #include <libcfs/list.h>
 
-extern spinlock_t obd_types_lock;
-
 enum {
        LU_CACHE_PERCENT_MAX     = 50,
        LU_CACHE_PERCENT_DEFAULT = 20
@@ -121,10 +114,10 @@ void lu_object_put(const struct lu_env *env, struct lu_object *o)
        if (fid_is_zero(fid)) {
                LASSERT(top->loh_hash.next == NULL
                        && top->loh_hash.pprev == NULL);
-               LASSERT(cfs_list_empty(&top->loh_lru));
+               LASSERT(list_empty(&top->loh_lru));
                if (!atomic_dec_and_test(&top->loh_ref))
                        return;
-               cfs_list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
+               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);
                }
@@ -147,20 +140,20 @@ void lu_object_put(const struct lu_env *env, struct lu_object *o)
                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.
          */
-        cfs_list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
+       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(cfs_list_empty(&top->loh_lru));
-                cfs_list_add_tail(&top->loh_lru, &bkt->lsb_lru);
+       if (!lu_object_is_dying(top) &&
+           (lu_object_exists(orig) || lu_object_is_cl(orig))) {
+               LASSERT(list_empty(&top->loh_lru));
+               list_add_tail(&top->loh_lru, &bkt->lsb_lru);
+               bkt->lsb_lru_len++;
                 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
                 return;
         }
@@ -213,7 +206,13 @@ void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
                cfs_hash_bd_t bd;
 
                cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1);
-               cfs_list_del_init(&top->loh_lru);
+               if (!list_empty(&top->loh_lru)) {
+                       struct lu_site_bkt_data *bkt;
+
+                       list_del_init(&top->loh_lru);
+                       bkt = cfs_hash_bd_extra_get(obj_hash, &bd);
+                       bkt->lsb_lru_len--;
+               }
                cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
                cfs_hash_bd_unlock(obj_hash, &bd, 1);
        }
@@ -233,7 +232,7 @@ static struct lu_object *lu_object_alloc(const struct lu_env *env,
 {
        struct lu_object *scan;
        struct lu_object *top;
-       cfs_list_t *layers;
+       struct list_head *layers;
        unsigned int init_mask = 0;
        unsigned int init_flag;
        int clean;
@@ -263,7 +262,7 @@ static struct lu_object *lu_object_alloc(const struct lu_env *env,
                 */
                clean = 1;
                init_flag = 1;
-               cfs_list_for_each_entry(scan, layers, lo_linkage) {
+               list_for_each_entry(scan, layers, lo_linkage) {
                        if (init_mask & init_flag)
                                goto next;
                        clean = 0;
@@ -279,7 +278,7 @@ next:
                }
        } while (!clean);
 
-        cfs_list_for_each_entry_reverse(scan, layers, lo_linkage) {
+       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) {
@@ -298,11 +297,11 @@ next:
  */
 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;
-        cfs_list_t              *layers;
-        cfs_list_t               splice;
+       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;
@@ -310,7 +309,7 @@ static void lu_object_free(const struct lu_env *env, struct lu_object *o)
         /*
          * First call ->loo_object_delete() method to release all resources.
          */
-        cfs_list_for_each_entry_reverse(scan, layers, lo_linkage) {
+       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);
         }
@@ -321,16 +320,16 @@ static void lu_object_free(const struct lu_env *env, struct lu_object *o)
          * necessary, because lu_object_header is freed together with the
          * top-level slice.
          */
-        CFS_INIT_LIST_HEAD(&splice);
-        cfs_list_splice_init(layers, &splice);
-       while (!cfs_list_empty(&splice)) {
+       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);
-               cfs_list_del_init(&o->lo_linkage);
+               list_del_init(&o->lo_linkage);
                LASSERT(o->lo_ops->loo_object_free != NULL);
                o->lo_ops->loo_object_free(env, o);
        }
@@ -349,23 +348,23 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
         struct lu_site_bkt_data *bkt;
         cfs_hash_bd_t            bd;
         cfs_hash_bd_t            bd2;
-        cfs_list_t               dispose;
-        int                      did_sth;
-        int                      start;
+       struct list_head         dispose;
+       int                      did_sth;
+       unsigned int             start;
         int                      count;
         int                      bnr;
-        int                      i;
+       unsigned int             i;
 
        if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU))
                RETURN(0);
 
-        CFS_INIT_LIST_HEAD(&dispose);
+       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;
+       bnr = (nr == ~0) ? -1 : nr / (int)CFS_HASH_NBKT(s->ls_obj_hash) + 1;
  again:
        /*
         * It doesn't make any sense to make purge threads parallel, that can
@@ -380,7 +379,7 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
                 cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1);
                 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
 
-                cfs_list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) {
+               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);
@@ -388,7 +387,8 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
 
                         cfs_hash_bd_del_locked(s->ls_obj_hash,
                                                &bd2, &h->loh_hash);
-                        cfs_list_move(&h->loh_lru, &dispose);
+                       list_move(&h->loh_lru, &dispose);
+                       bkt->lsb_lru_len--;
                         if (did_sth == 0)
                                 did_sth = 1;
 
@@ -405,13 +405,13 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
                 * Free everything on the dispose list. This is safe against
                 * races due to the reasons described in lu_object_put().
                 */
-                while (!cfs_list_empty(&dispose)) {
-                        h = container_of0(dispose.next,
-                                          struct lu_object_header, loh_lru);
-                        cfs_list_del_init(&h->loh_lru);
-                        lu_object_free(env, lu_object_top(h));
-                        lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED);
-                }
+               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;
@@ -468,7 +468,7 @@ 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 = {
+static 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,
@@ -516,13 +516,13 @@ 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]",
+       (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
                   hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
-                   PFID(&hdr->loh_fid),
-                   cfs_hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
-                   cfs_list_empty((cfs_list_t *)&hdr->loh_lru) ? \
-                   "" : " lru",
-                   hdr->loh_attr & LOHA_EXISTS ? " exist":"");
+                  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);
 
@@ -540,7 +540,7 @@ void lu_object_print(const struct lu_env *env, void *cookie,
        lu_object_header_print(env, cookie, printer, top);
        (*printer)(env, cookie, "{\n");
 
-       cfs_list_for_each_entry(o, &top->loh_layers, lo_linkage) {
+       list_for_each_entry(o, &top->loh_layers, lo_linkage) {
                /*
                 * print `.' \a depth times followed by type name and address
                 */
@@ -565,14 +565,13 @@ int lu_object_invariant(const struct lu_object *o)
         struct lu_object_header *top;
 
         top = o->lo_header;
-        cfs_list_for_each_entry(o, &top->loh_layers, lo_linkage) {
+       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,
                                       cfs_hash_bd_t *bd,
@@ -580,10 +579,10 @@ static struct lu_object *htable_lookup(struct lu_site *s,
                                       wait_queue_t *waiter,
                                       __u64 *version)
 {
-        struct lu_site_bkt_data *bkt;
-        struct lu_object_header *h;
-        cfs_hlist_node_t        *hnode;
-        __u64  ver = cfs_hash_bd_version_get(bd);
+       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);
@@ -602,7 +601,10 @@ static struct lu_object *htable_lookup(struct lu_site *s,
         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);
-                cfs_list_del_init(&h->loh_lru);
+               if (!list_empty(&h->loh_lru)) {
+                       list_del_init(&h->loh_lru);
+                       bkt->lsb_lru_len--;
+               }
                 return lu_object_top(h);
         }
 
@@ -612,36 +614,14 @@ static struct lu_object *htable_lookup(struct lu_site *s,
          * drained), and moreover, lookup has to wait until object is freed.
          */
 
-       init_waitqueue_entry_current(waiter);
-       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);
-}
-
-static struct lu_object *htable_lookup_nowait(struct lu_site *s,
-                                             cfs_hash_bd_t *bd,
-                                             const struct lu_fid *f)
-{
-       cfs_hlist_node_t        *hnode;
-       struct lu_object_header *h;
-
-       /* 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);
+       if (likely(waiter != NULL)) {
+               init_waitqueue_entry_current(waiter);
+               add_wait_queue(&bkt->lsb_marche_funebre, waiter);
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE);
        }
 
-       h = container_of0(hnode, struct lu_object_header, loh_hash);
-       if (unlikely(lu_object_is_dying(h)))
-               return ERR_PTR(-ENOENT);
-
-       cfs_hash_get(s->ls_obj_hash, hnode);
-       lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT);
-       cfs_list_del_init(&h->loh_lru);
-       return lu_object_top(h);
+       return ERR_PTR(-EAGAIN);
 }
 
 /**
@@ -689,7 +669,6 @@ static struct lu_object *lu_object_new(const struct lu_env *env,
         struct lu_object        *o;
         cfs_hash_t              *hs;
         cfs_hash_bd_t            bd;
-        struct lu_site_bkt_data *bkt;
 
         o = lu_object_alloc(env, dev, f, conf);
         if (unlikely(IS_ERR(o)))
@@ -697,9 +676,7 @@ static struct lu_object *lu_object_new(const struct lu_env *env,
 
         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);
 
        lu_object_limit(env, dev);
@@ -768,11 +745,7 @@ static struct lu_object *lu_object_find_try(const struct lu_env *env,
 
         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);
 
                lu_object_limit(env, dev);
@@ -800,6 +773,9 @@ struct lu_object *lu_object_find_at(const struct lu_env *env,
        struct lu_object        *obj;
        wait_queue_t           wait;
 
+       if (conf != NULL && conf->loc_flags & LOC_F_NOWAIT)
+               return lu_object_find_try(env, dev, f, conf, NULL);
+
        while (1) {
                obj = lu_object_find_try(env, dev, f, conf, &wait);
                if (obj != ERR_PTR(-EAGAIN))
@@ -816,30 +792,6 @@ struct lu_object *lu_object_find_at(const struct lu_env *env,
 EXPORT_SYMBOL(lu_object_find_at);
 
 /**
- * Try to find the object in cache without waiting for the dead object
- * to be released nor allocating object if no cached one was found.
- *
- * The found object will be set as LU_OBJECT_HEARD_BANSHEE for purging.
- */
-void lu_object_purge(const struct lu_env *env, struct lu_device *dev,
-                    const struct lu_fid *f)
-{
-       struct lu_site          *s  = dev->ld_site;
-       cfs_hash_t              *hs = s->ls_obj_hash;
-       cfs_hash_bd_t            bd;
-       struct lu_object        *o;
-
-       cfs_hash_bd_get_and_lock(hs, f, &bd, 1);
-       o = htable_lookup_nowait(s, &bd, f);
-       cfs_hash_bd_unlock(hs, &bd, 1);
-       if (!IS_ERR(o)) {
-               set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags);
-               lu_object_put(env, o);
-       }
-}
-EXPORT_SYMBOL(lu_object_purge);
-
-/**
  * 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,
@@ -847,24 +799,27 @@ struct lu_object *lu_object_find_slice(const struct lu_env *env,
                                        const struct lu_fid *f,
                                        const struct lu_object_conf *conf)
 {
-        struct lu_object *top;
-        struct lu_object *obj;
+       struct lu_object *top;
+       struct lu_object *obj;
+
+       top = lu_object_find(env, dev, f, conf);
+       if (IS_ERR(top))
+               return top;
+
+       obj = lu_object_locate(top->lo_header, dev->ld_type);
+       if (unlikely(obj == NULL)) {
+               lu_object_put(env, top);
+               obj = ERR_PTR(-ENOENT);
+       }
 
-        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;
+       return obj;
 }
 EXPORT_SYMBOL(lu_object_find_slice);
 
 /**
  * Global list of all device types.
  */
-static CFS_LIST_HEAD(lu_device_types);
+static struct list_head lu_device_types;
 
 int lu_device_type_init(struct lu_device_type *ldt)
 {
@@ -898,7 +853,7 @@ EXPORT_SYMBOL(lu_device_type_fini);
 /**
  * Global list of all sites on this node
  */
-static CFS_LIST_HEAD(lu_sites);
+static struct list_head lu_sites;
 static DEFINE_MUTEX(lu_sites_guard);
 
 /**
@@ -914,23 +869,23 @@ struct lu_site_print_arg {
 
 static int
 lu_site_obj_print(cfs_hash_t *hs, cfs_hash_bd_t *bd,
-                  cfs_hlist_node_t *hnode, void *data)
+                 struct hlist_node *hnode, void *data)
 {
-        struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
-        struct lu_object_header  *h;
+       struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
+       struct lu_object_header  *h;
 
-        h = cfs_hlist_entry(hnode, struct lu_object_header, loh_hash);
-        if (!cfs_list_empty(&h->loh_layers)) {
-                const struct lu_object *o;
+       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;
+               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;
 }
 
 /**
@@ -952,10 +907,10 @@ EXPORT_SYMBOL(lu_site_print);
 /**
  * Return desired hash table order.
  */
-static int lu_htable_order(struct lu_device *top)
+static unsigned long lu_htable_order(struct lu_device *top)
 {
-        unsigned long cache_size;
-        int bits;
+       unsigned long cache_size;
+       unsigned long bits;
 
        /*
         * For ZFS based OSDs the cache should be disabled by default.  This
@@ -1021,48 +976,41 @@ static unsigned lu_obj_hop_hash(cfs_hash_t *hs,
        return hash & mask;
 }
 
-static void *lu_obj_hop_object(cfs_hlist_node_t *hnode)
+static void *lu_obj_hop_object(struct hlist_node *hnode)
 {
-        return cfs_hlist_entry(hnode, struct lu_object_header, loh_hash);
+       return hlist_entry(hnode, struct lu_object_header, loh_hash);
 }
 
-static void *lu_obj_hop_key(cfs_hlist_node_t *hnode)
+static void *lu_obj_hop_key(struct hlist_node *hnode)
 {
-        struct lu_object_header *h;
+       struct lu_object_header *h;
 
-        h = cfs_hlist_entry(hnode, struct lu_object_header, loh_hash);
-        return &h->loh_fid;
+       h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+       return &h->loh_fid;
 }
 
-static int lu_obj_hop_keycmp(const void *key, cfs_hlist_node_t *hnode)
+static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode)
 {
-        struct lu_object_header *h;
+       struct lu_object_header *h;
 
-        h = cfs_hlist_entry(hnode, struct lu_object_header, loh_hash);
-        return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key);
+       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(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
+static void lu_obj_hop_get(cfs_hash_t *hs, struct hlist_node *hnode)
 {
-        struct lu_object_header *h;
-
-        h = cfs_hlist_entry(hnode, struct lu_object_header, loh_hash);
-       if (atomic_add_return(1, &h->loh_ref) == 1) {
-                struct lu_site_bkt_data *bkt;
-                cfs_hash_bd_t            bd;
+       struct lu_object_header *h;
 
-                cfs_hash_bd_get(hs, &h->loh_fid, &bd);
-                bkt = cfs_hash_bd_extra_get(hs, &bd);
-                bkt->lsb_busy++;
-        }
+       h = hlist_entry(hnode, struct lu_object_header, loh_hash);
+       atomic_inc(&h->loh_ref);
 }
 
-static void lu_obj_hop_put_locked(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
+static void lu_obj_hop_put_locked(cfs_hash_t *hs, struct hlist_node *hnode)
 {
         LBUG(); /* we should never called it */
 }
 
-cfs_hash_ops_t lu_site_hash_ops = {
+static 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,
@@ -1074,8 +1022,8 @@ cfs_hash_ops_t lu_site_hash_ops = {
 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d)
 {
        spin_lock(&s->ls_ld_lock);
-       if (cfs_list_empty(&d->ld_linkage))
-               cfs_list_add(&d->ld_linkage, &s->ls_ld_linkage);
+       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);
@@ -1083,7 +1031,7 @@ 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);
-       cfs_list_del_init(&d->ld_linkage);
+       list_del_init(&d->ld_linkage);
        spin_unlock(&s->ls_ld_lock);
 }
 EXPORT_SYMBOL(lu_dev_del_linkage);
@@ -1096,15 +1044,16 @@ int lu_site_init(struct lu_site *s, struct lu_device *top)
        struct lu_site_bkt_data *bkt;
        cfs_hash_bd_t bd;
        char name[16];
-       int bits;
-       int i;
+       unsigned long bits;
+       unsigned int i;
        ENTRY;
 
        memset(s, 0, sizeof *s);
        mutex_init(&s->ls_purge_mutex);
        bits = lu_htable_order(top);
-       snprintf(name, 16, "lu_site_%s", top->ld_type->ldt_name);
-       for (bits = min(max(LU_SITE_BITS_MIN, bits), LU_SITE_BITS_MAX);
+       snprintf(name, sizeof(name), "lu_site_%s", top->ld_type->ldt_name);
+       for (bits = clamp_t(typeof(bits), bits,
+                           LU_SITE_BITS_MIN, 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,
@@ -1120,13 +1069,13 @@ int lu_site_init(struct lu_site *s, struct lu_device *top)
        }
 
        if (s->ls_obj_hash == NULL) {
-               CERROR("failed to create lu_site hash with bits: %d\n", bits);
+               CERROR("failed to create lu_site hash with bits: %lu\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);
-               CFS_INIT_LIST_HEAD(&bkt->lsb_lru);
+               INIT_LIST_HEAD(&bkt->lsb_lru);
                init_waitqueue_head(&bkt->lsb_marche_funebre);
        }
 
@@ -1150,13 +1099,13 @@ int lu_site_init(struct lu_site *s, struct lu_device *top)
         lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
                              0, "lru_purged", "lru_purged");
 
-        CFS_INIT_LIST_HEAD(&s->ls_linkage);
+       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);
 
-        CFS_INIT_LIST_HEAD(&s->ls_ld_linkage);
+       INIT_LIST_HEAD(&s->ls_ld_linkage);
        spin_lock_init(&s->ls_ld_lock);
 
        lu_dev_add_linkage(s, top);
@@ -1171,7 +1120,7 @@ EXPORT_SYMBOL(lu_site_init);
 void lu_site_fini(struct lu_site *s)
 {
        mutex_lock(&lu_sites_guard);
-        cfs_list_del_init(&s->ls_linkage);
+       list_del_init(&s->ls_linkage);
        mutex_unlock(&lu_sites_guard);
 
         if (s->ls_obj_hash != NULL) {
@@ -1200,7 +1149,7 @@ int lu_site_init_finish(struct lu_site *s)
        mutex_lock(&lu_sites_guard);
         result = lu_context_refill(&lu_shrink_env.le_ctx);
         if (result == 0)
-                cfs_list_add(&s->ls_linkage, &lu_sites);
+               list_add(&s->ls_linkage, &lu_sites);
        mutex_unlock(&lu_sites_guard);
         return result;
 }
@@ -1278,7 +1227,7 @@ int lu_object_init(struct lu_object *o, struct lu_object_header *h,
        o->lo_dev = d;
        lu_device_get(d);
        lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o);
-       CFS_INIT_LIST_HEAD(&o->lo_linkage);
+       INIT_LIST_HEAD(&o->lo_linkage);
 
        return 0;
 }
@@ -1291,7 +1240,7 @@ void lu_object_fini(struct lu_object *o)
 {
        struct lu_device *dev = o->lo_dev;
 
-       LASSERT(cfs_list_empty(&o->lo_linkage));
+       LASSERT(list_empty(&o->lo_linkage));
 
        if (dev != NULL) {
                lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref,
@@ -1310,7 +1259,7 @@ EXPORT_SYMBOL(lu_object_fini);
  */
 void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
 {
-        cfs_list_move(&o->lo_linkage, &h->loh_layers);
+       list_move(&o->lo_linkage, &h->loh_layers);
 }
 EXPORT_SYMBOL(lu_object_add_top);
 
@@ -1322,7 +1271,7 @@ EXPORT_SYMBOL(lu_object_add_top);
  */
 void lu_object_add(struct lu_object *before, struct lu_object *o)
 {
-        cfs_list_move(&o->lo_linkage, &before->lo_linkage);
+       list_move(&o->lo_linkage, &before->lo_linkage);
 }
 EXPORT_SYMBOL(lu_object_add);
 
@@ -1333,9 +1282,9 @@ int lu_object_header_init(struct lu_object_header *h)
 {
         memset(h, 0, sizeof *h);
        atomic_set(&h->loh_ref, 1);
-        CFS_INIT_HLIST_NODE(&h->loh_hash);
-        CFS_INIT_LIST_HEAD(&h->loh_lru);
-        CFS_INIT_LIST_HEAD(&h->loh_layers);
+       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;
 }
@@ -1346,9 +1295,9 @@ EXPORT_SYMBOL(lu_object_header_init);
  */
 void lu_object_header_fini(struct lu_object_header *h)
 {
-        LASSERT(cfs_list_empty(&h->loh_layers));
-        LASSERT(cfs_list_empty(&h->loh_lru));
-        LASSERT(cfs_hlist_unhashed(&h->loh_hash));
+       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);
@@ -1360,18 +1309,16 @@ EXPORT_SYMBOL(lu_object_header_fini);
 struct lu_object *lu_object_locate(struct lu_object_header *h,
                                    const struct lu_device_type *dtype)
 {
-        struct lu_object *o;
+       struct lu_object *o;
 
-        cfs_list_for_each_entry(o, &h->loh_layers, lo_linkage) {
-                if (o->lo_dev->ld_type == dtype)
-                        return o;
-        }
-        return NULL;
+       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.
  *
@@ -1407,7 +1354,6 @@ void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
                 }
         }
 }
-EXPORT_SYMBOL(lu_stack_fini);
 
 enum {
         /**
@@ -1419,6 +1365,7 @@ enum {
 static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
 
 static DEFINE_SPINLOCK(lu_keys_guard);
+static atomic_t lu_key_initing_cnt = ATOMIC_INIT(0);
 
 /**
  * Global counter incremented whenever key is registered, unregistered,
@@ -1433,8 +1380,8 @@ static unsigned key_set_version = 0;
  */
 int lu_context_key_register(struct lu_context_key *key)
 {
-        int result;
-        int i;
+       int result;
+       unsigned int i;
 
         LASSERT(key->lct_init != NULL);
         LASSERT(key->lct_fini != NULL);
@@ -1495,6 +1442,19 @@ void lu_context_key_degister(struct lu_context_key *key)
        ++key_set_version;
        spin_lock(&lu_keys_guard);
        key_fini(&lu_shrink_env.le_ctx, key->lct_index);
+
+       /**
+        * Wait until all transient contexts referencing this key have
+        * run lu_context_key::lct_fini() method.
+        */
+       while (atomic_read(&key->lct_used) > 1) {
+               spin_unlock(&lu_keys_guard);
+               CDEBUG(D_INFO, "lu_context_key_degister: \"%s\" %p, %d\n",
+                      key->lct_owner ? key->lct_owner->name : "", key,
+                      atomic_read(&key->lct_used));
+               schedule();
+               spin_lock(&lu_keys_guard);
+       }
        if (lu_keys[key->lct_index]) {
                lu_keys[key->lct_index] = NULL;
                lu_ref_fini(&key->lct_reference);
@@ -1604,7 +1564,7 @@ EXPORT_SYMBOL(lu_context_key_get);
 /**
  * List of remembered contexts. XXX document me.
  */
-static CFS_LIST_HEAD(lu_context_remembered);
+static struct list_head lu_context_remembered;
 
 /**
  * Destroy \a key in all remembered contexts. This is used to destroy key
@@ -1621,30 +1581,44 @@ void lu_context_key_quiesce(struct lu_context_key *key)
                  * XXX layering violation.
                  */
                 cl_env_cache_purge(~0);
-                key->lct_tags |= LCT_QUIESCENT;
                 /*
                  * XXX memory barrier has to go here.
                  */
                spin_lock(&lu_keys_guard);
-               cfs_list_for_each_entry(ctx, &lu_context_remembered,
-                                       lc_remember)
+               key->lct_tags |= LCT_QUIESCENT;
+
+               /**
+                * Wait until all lu_context_key::lct_init() methods
+                * have completed.
+                */
+               while (atomic_read(&lu_key_initing_cnt) > 0) {
+                       spin_unlock(&lu_keys_guard);
+                       CDEBUG(D_INFO, "lu_context_key_quiesce: \"%s\""
+                              " %p, %d (%d)\n",
+                              key->lct_owner ? key->lct_owner->name : "",
+                              key, atomic_read(&key->lct_used),
+                              atomic_read(&lu_key_initing_cnt));
+                       schedule();
+                       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;
+       unsigned int i;
 
        if (ctx->lc_value == NULL)
                return;
@@ -1658,7 +1632,20 @@ static void keys_fini(struct lu_context *ctx)
 
 static int keys_fill(struct lu_context *ctx)
 {
-        int i;
+       unsigned int i;
+
+       /*
+        * A serialisation with lu_context_key_quiesce() is needed, but some
+        * "key->lct_init()" are calling kernel memory allocation routine and
+        * can't be called while holding a spin_lock.
+        * "lu_keys_guard" is held while incrementing "lu_key_initing_cnt"
+        * to ensure the start of the serialisation.
+        * An atomic_t variable is still used, in order not to reacquire the
+        * lock when decrementing the counter.
+        */
+       spin_lock(&lu_keys_guard);
+       atomic_inc(&lu_key_initing_cnt);
+       spin_unlock(&lu_keys_guard);
 
         LINVRNT(ctx->lc_value != NULL);
         for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
@@ -1677,13 +1664,19 @@ static int keys_fill(struct lu_context *ctx)
                         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);
-
                        LASSERT(key->lct_owner != NULL);
-                       if (!(ctx->lc_tags & LCT_NOREF))
-                               try_module_get(key->lct_owner);
+                       if (!(ctx->lc_tags & LCT_NOREF) &&
+                           try_module_get(key->lct_owner) == 0) {
+                               /* module is unloading, skip this key */
+                               continue;
+                       }
+
+                       value = key->lct_init(ctx, key);
+                       if (unlikely(IS_ERR(value))) {
+                               atomic_dec(&lu_key_initing_cnt);
+                               return PTR_ERR(value);
+                       }
+
                        lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
                        atomic_inc(&key->lct_used);
                         /*
@@ -1697,6 +1690,7 @@ static int keys_fill(struct lu_context *ctx)
                 }
                 ctx->lc_version = key_set_version;
         }
+       atomic_dec(&lu_key_initing_cnt);
         return 0;
 }
 
@@ -1721,10 +1715,10 @@ int lu_context_init(struct lu_context *ctx, __u32 tags)
        ctx->lc_tags = tags;
        if (tags & LCT_REMEMBER) {
                spin_lock(&lu_keys_guard);
-               cfs_list_add(&ctx->lc_remember, &lu_context_remembered);
+               list_add(&ctx->lc_remember, &lu_context_remembered);
                spin_unlock(&lu_keys_guard);
        } else {
-               CFS_INIT_LIST_HEAD(&ctx->lc_remember);
+               INIT_LIST_HEAD(&ctx->lc_remember);
        }
 
        rc = keys_init(ctx);
@@ -1744,13 +1738,13 @@ void lu_context_fini(struct lu_context *ctx)
        ctx->lc_state = LCS_FINALIZED;
 
        if ((ctx->lc_tags & LCT_REMEMBER) == 0) {
-               LASSERT(cfs_list_empty(&ctx->lc_remember));
+               LASSERT(list_empty(&ctx->lc_remember));
                keys_fini(ctx);
 
        } else { /* could race with key degister */
                spin_lock(&lu_keys_guard);
                keys_fini(ctx);
-               cfs_list_del_init(&ctx->lc_remember);
+               list_del_init(&ctx->lc_remember);
                spin_unlock(&lu_keys_guard);
        }
 }
@@ -1771,21 +1765,26 @@ EXPORT_SYMBOL(lu_context_enter);
  */
 void lu_context_exit(struct lu_context *ctx)
 {
-        int i;
+       unsigned 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]);
-                        }
+                       /* could race with key quiescency */
+                       if (ctx->lc_tags & LCT_REMEMBER)
+                               spin_lock(&lu_keys_guard);
+                       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]);
+                       }
+                       if (ctx->lc_tags & LCT_REMEMBER)
+                               spin_unlock(&lu_keys_guard);
                 }
         }
 }
@@ -1800,7 +1799,6 @@ 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
@@ -1919,15 +1917,16 @@ typedef struct lu_site_stats{
 static void lu_site_stats_get(cfs_hash_t *hs,
                               lu_site_stats_t *stats, int populated)
 {
-        cfs_hash_bd_t bd;
-        int           i;
+       cfs_hash_bd_t bd;
+       unsigned int  i;
 
         cfs_hash_for_each_bucket(hs, &bd, i) {
                 struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd);
-                cfs_hlist_head_t        *hhead;
+               struct hlist_head       *hhead;
 
                 cfs_hash_bd_lock(hs, &bd, 1);
-                stats->lss_busy  += bkt->lsb_busy;
+               stats->lss_busy  +=
+                       cfs_hash_bd_count_get(&bd) - bkt->lsb_lru_len;
                 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));
@@ -1937,14 +1936,13 @@ static void lu_site_stats_get(cfs_hash_t *hs,
                 }
 
                 cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
-                        if (!cfs_hlist_empty(hhead))
+                       if (!hlist_empty(hhead))
                                 stats->lss_populated++;
                 }
                 cfs_hash_bd_unlock(hs, &bd, 1);
         }
 }
 
-#ifdef __KERNEL__
 
 static unsigned long lu_cache_shrink_count(struct shrinker *sk,
                                           struct shrink_control *sc)
@@ -2058,13 +2056,13 @@ static int lu_cache_shrink(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask))
 /**
  * Environment to be used in debugger, contains all tags.
  */
-struct lu_env lu_debugging_env;
+static 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, ...)
+                     void *unused, const char *format, ...)
 {
         va_list args;
 
@@ -2081,7 +2079,7 @@ int lu_debugging_setup(void)
 
 void lu_context_keys_dump(void)
 {
-        int i;
+       unsigned int i;
 
         for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
                 struct lu_context_key *key;
@@ -2098,8 +2096,6 @@ void lu_context_keys_dump(void)
                 }
         }
 }
-EXPORT_SYMBOL(lu_context_keys_dump);
-#endif /* __KERNEL__ */
 
 /**
  * Initialization of global lu_* data.
@@ -2112,6 +2108,10 @@ int lu_global_init(void)
 
         CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys);
 
+       INIT_LIST_HEAD(&lu_device_types);
+       INIT_LIST_HEAD(&lu_context_remembered);
+       INIT_LIST_HEAD(&lu_sites);
+
         result = lu_ref_global_init();
         if (result != 0)
                 return result;
@@ -2169,7 +2169,7 @@ void lu_global_fini(void)
 
 static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
 {
-#ifdef LPROCFS
+#ifdef CONFIG_PROC_FS
         struct lprocfs_counter ret;
 
         lprocfs_stats_collect(stats, idx, &ret);
@@ -2225,7 +2225,6 @@ int lu_site_stats_print(const struct lu_site *s, char *page, int count)
                         ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
                         ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
 }
-EXPORT_SYMBOL(lu_site_stats_print);
 
 /**
  * Helper function to initialize a number of kmem slab caches at once.
@@ -2274,7 +2273,6 @@ void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
 {
        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;
        cfs_hash_t              *hs;
@@ -2289,9 +2287,7 @@ void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
        /* 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);
@@ -2333,7 +2329,7 @@ void lu_buf_free(struct lu_buf *buf)
 }
 EXPORT_SYMBOL(lu_buf_free);
 
-void lu_buf_alloc(struct lu_buf *buf, int size)
+void lu_buf_alloc(struct lu_buf *buf, size_t size)
 {
        LASSERT(buf);
        LASSERT(buf->lb_buf == NULL);
@@ -2344,14 +2340,14 @@ void lu_buf_alloc(struct lu_buf *buf, int size)
 }
 EXPORT_SYMBOL(lu_buf_alloc);
 
-void lu_buf_realloc(struct lu_buf *buf, int size)
+void lu_buf_realloc(struct lu_buf *buf, size_t 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)
+struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, size_t len)
 {
        if (buf->lb_buf == NULL && buf->lb_len == 0)
                lu_buf_alloc(buf, len);
@@ -2369,7 +2365,7 @@ EXPORT_SYMBOL(lu_buf_check_and_alloc);
  * old buffer remains unchanged on error
  * \retval 0 or -ENOMEM
  */
-int lu_buf_check_and_grow(struct lu_buf *buf, int len)
+int lu_buf_check_and_grow(struct lu_buf *buf, size_t len)
 {
        char *ptr;
 
@@ -2390,5 +2386,3 @@ int lu_buf_check_and_grow(struct lu_buf *buf, int len)
        buf->lb_len = len;
        return 0;
 }
-EXPORT_SYMBOL(lu_buf_check_and_grow);
-