diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/obdclass/lu_object.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/obdclass/lu_object.c | 2185 |
1 files changed, 2185 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c new file mode 100644 index 000000000000..fdf0ed367693 --- /dev/null +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c @@ -0,0 +1,2185 @@ +/* + * 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 <linux/libcfs/libcfs.h> + +# include <linux/module.h> + +/* hash_long() */ +#include <linux/libcfs/libcfs_hash.h> +#include <obd_class.h> +#include <obd_support.h> +#include <lustre_disk.h> +#include <lustre_fid.h> +#include <lu_object.h> +#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; + cfs_hash_bd_t 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)) { + cfs_hash_t *obj_hash = o->lo_dev->ld_site->ls_obj_hash; + cfs_hash_bd_t 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; + int clean; + int result; + ENTRY; + + /* + * 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; + list_for_each_entry(scan, layers, lo_linkage) { + if (scan->lo_flags & LU_OBJECT_ALLOCATED) + continue; + 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)); + } + scan->lo_flags |= LU_OBJECT_ALLOCATED; + } + } 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; + cfs_hash_bd_t bd; + cfs_hash_bd_t 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_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; + + 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) { + depth = o->lo_depth + 4; + + /* + * 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, + cfs_hash_bd_t *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 NULL; + + *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 NULL; + } + + 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_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); +} + +/** + * 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; + 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))) + 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; + cfs_hash_t *hs; + cfs_hash_bd_t 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 (o != NULL) + 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(shadow == NULL)) { + 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. + */ + waitq_wait(&wait, TASK_UNINTERRUPTIBLE); + 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(cfs_hash_t *hs, cfs_hash_bd_t *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; +CFS_MODULE_PARM(lu_cache_percent, "i", int, 0644, + "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 = num_physpages; + +#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(cfs_hash_t *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 = cfs_hash_long(hash, hs->hs_bkt_bits); + + /* give me another random factor */ + hash -= cfs_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(cfs_hash_t *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; + cfs_hash_bd_t 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(cfs_hash_t *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; + cfs_hash_bd_t bd; + char name[16]; + int bits; + int i; + ENTRY; + + 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); + o->lo_dev_ref = lu_ref_add(&d->ld_reference, "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 = 0; + +/** + * 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); + LASSERT(key->lct_owner != NULL); + + 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); + + LASSERT(key->lct_owner != NULL); + 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); + + LASSERT(key->lct_owner != NULL); + 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) +{ + int result; + + 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; + } + + result = lu_env_refill(env); + + return result; +} +EXPORT_SYMBOL(lu_env_refill_by_tags); + +static struct shrinker *lu_site_shrinker = NULL; + +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(cfs_hash_t *hs, + lu_site_stats_t *stats, int populated) +{ + cfs_hash_bd_t 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 int lu_cache_shrink(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask)) +{ + lu_site_stats_t stats; + struct lu_site *s; + struct lu_site *tmp; + int cached = 0; + int remain = shrink_param(sc, nr_to_scan); + LIST_HEAD(splice); + + if (!(shrink_param(sc, gfp_mask) & __GFP_FS)) { + if (remain != 0) + return -1; + else + /* 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 0; + } + + CDEBUG(D_INODE, "Shrink %d objects\n", remain); + + mutex_lock(&lu_sites_guard); + list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) { + if (shrink_param(sc, nr_to_scan) != 0) { + remain = lu_site_purge(&lu_shrink_env, s, remain); + /* + * Move just shrunk site to the tail of site list to + * assure shrinking fairness. + */ + list_move_tail(&s->ls_linkage, &splice); + } + + memset(&stats, 0, sizeof(stats)); + lu_site_stats_get(s->ls_obj_hash, &stats, 0); + cached += stats.lss_total - stats.lss_busy; + if (shrink_param(sc, nr_to_scan) && remain <= 0) + break; + } + list_splice(&splice, lu_sites.prev); + mutex_unlock(&lu_sites_guard); + + cached = (cached / 100) * sysctl_vfs_cache_pressure; + if (shrink_param(sc, nr_to_scan) == 0) + CDEBUG(D_INODE, "%d objects cached\n", cached); + return cached; +} + +/* + * 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; +} + +/** + * 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. + */ + lu_site_shrinker = set_shrinker(DEFAULT_SEEKS, lu_cache_shrink); + if (lu_site_shrinker == NULL) + return -ENOMEM; + + return result; +} + +/** + * Dual to lu_global_init(). + */ +void lu_global_fini(void) +{ + if (lu_site_shrinker != NULL) { + remove_shrinker(lu_site_shrinker); + lu_site_shrinker = NULL; + } + + 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) +{ +#ifdef LPROCFS + 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); + + return 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)); +} +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; + cfs_hash_t *hs; + cfs_hash_bd_t 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(shadow == NULL); + *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-assiged) 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); |