/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * * 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 2008 Sun Microsystems, Inc. All rights reserved * Use is subject to license terms. */ /* * 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 */ #define DEBUG_SUBSYSTEM S_CLASS #ifndef EXPORT_SYMTAB # define EXPORT_SYMTAB #endif #include #ifdef __KERNEL__ # include #endif /* hash_long() */ #include #include #include #include #include #include #include /* lu_time_global_{init,fini}() */ #include 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_object_header *top; struct lu_site *site; struct lu_object *orig; int kill_it; top = o->lo_header; site = o->lo_dev->ld_site; orig = o; kill_it = 0; cfs_write_lock(&site->ls_guard); if (cfs_atomic_dec_and_test(&top->loh_ref)) { /* * 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) { if (o->lo_ops->loo_object_release != NULL) o->lo_ops->loo_object_release(env, o); } -- site->ls_busy; if (lu_object_is_dying(top)) { /* * 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. */ cfs_hlist_del_init(&top->loh_hash); cfs_list_del_init(&top->loh_lru); -- site->ls_total; kill_it = 1; } } cfs_write_unlock(&site->ls_guard); if (kill_it) /* * Object was already removed from hash and lru above, can * kill it. */ lu_object_free(env, orig); } EXPORT_SYMBOL(lu_object_put); /** * 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; cfs_list_t *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)); /* * This is the only place where object fid is assigned. It's constant * after this point. */ LASSERT(fid_is_igif(f) || fid_ver(f) == 0); 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; cfs_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); cfs_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)); } } } dev->ld_site->ls_stats.s_created ++; RETURN(top); } /** * Free an object. */ static void lu_object_free(const struct lu_env *env, struct lu_object *o) { cfs_list_t splice; struct lu_object *scan; struct lu_site *site; cfs_list_t *layers; site = o->lo_dev->ld_site; layers = &o->lo_header->loh_layers; /* * First call ->loo_object_delete() method to release all resources. */ cfs_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. */ CFS_INIT_LIST_HEAD(&splice); cfs_list_splice_init(layers, &splice); while (!cfs_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); LASSERT(o->lo_ops->loo_object_free != NULL); o->lo_ops->loo_object_free(env, o); } cfs_waitq_broadcast(&site->ls_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) { cfs_list_t dispose; struct lu_object_header *h; struct lu_object_header *temp; CFS_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. */ cfs_write_lock(&s->ls_guard); cfs_list_for_each_entry_safe(h, temp, &s->ls_lru, loh_lru) { /* * Objects are sorted in lru order, and "busy" objects (ones * with h->loh_ref > 0) naturally tend to live near hot end * that we scan last. Unfortunately, sites usually have small * (less then ten) number of busy yet rarely accessed objects * (some global objects, accessed directly through pointers, * bypassing hash table). Currently algorithm scans them over * and over again. Probably we should move busy objects out of * LRU, or we can live with that. */ if (nr-- == 0) break; if (cfs_atomic_read(&h->loh_ref) > 0) continue; cfs_hlist_del_init(&h->loh_hash); cfs_list_move(&h->loh_lru, &dispose); s->ls_total --; } cfs_write_unlock(&s->ls_guard); /* * 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)); s->ls_stats.s_lru_purged ++; } 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 = 256 }; 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_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 lu_cdebug_print_info *info = 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(info->lpi_mask, info->lpi_subsys)) libcfs_debug_msg(NULL, info->lpi_subsys, info->lpi_mask, (char *)info->lpi_file, info->lpi_fn, info->lpi_line, "%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, cfs_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":""); } 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"); cfs_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; cfs_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, const cfs_hlist_head_t *bucket, const struct lu_fid *f, cfs_waitlink_t *waiter) { struct lu_object_header *h; cfs_hlist_node_t *scan; cfs_hlist_for_each_entry(h, scan, bucket, loh_hash) { s->ls_stats.s_cache_check ++; if (likely(lu_fid_eq(&h->loh_fid, f))) { if (unlikely(lu_object_is_dying(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. */ cfs_waitlink_init(waiter); cfs_waitq_add(&s->ls_marche_funebre, waiter); cfs_set_current_state(CFS_TASK_UNINT); s->ls_stats.s_cache_death_race ++; return ERR_PTR(-EAGAIN); } /* bump reference count... */ if (cfs_atomic_add_return(1, &h->loh_ref) == 1) ++ s->ls_busy; /* and move to the head of the LRU */ /* * XXX temporary disable this to measure effects of * read-write locking. */ /* list_move_tail(&h->loh_lru, &s->ls_lru); */ s->ls_stats.s_cache_hit ++; return lu_object_top(h); } } s->ls_stats.s_cache_miss ++; return NULL; } static __u32 fid_hash(const struct lu_fid *f, int bits) { /* all objects with same id and different versions will belong to same * collisions list. */ return cfs_hash_long(fid_flatten(f), bits); } /** * 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); /** * 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, cfs_waitlink_t *waiter) { struct lu_site *s; struct lu_object *o; struct lu_object *shadow; cfs_hlist_head_t *bucket; /* * 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. * * If dying object is found during index search, add @waiter to the * site wait-queue and return ERR_PTR(-EAGAIN). */ s = dev->ld_site; bucket = s->ls_hash + fid_hash(f, s->ls_hash_bits); cfs_read_lock(&s->ls_guard); o = htable_lookup(s, bucket, f, waiter); cfs_read_unlock(&s->ls_guard); 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_write_lock(&s->ls_guard); shadow = htable_lookup(s, bucket, f, waiter); if (likely(shadow == NULL)) { cfs_hlist_add_head(&o->lo_header->loh_hash, bucket); cfs_list_add_tail(&o->lo_header->loh_lru, &s->ls_lru); ++ s->ls_busy; ++ s->ls_total; shadow = o; o = NULL; } else s->ls_stats.s_cache_race ++; cfs_write_unlock(&s->ls_guard); if (o != NULL) 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_object *obj; cfs_waitlink_t wait; while (1) { obj = lu_object_find_try(env, dev, f, conf, &wait); if (obj == ERR_PTR(-EAGAIN)) { /* * lu_object_find_try() already added waiter into the * wait queue. */ cfs_waitq_wait(&wait, CFS_TASK_UNINT); cfs_waitq_del(&dev->ld_site->ls_marche_funebre, &wait); } else break; } return obj; } 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 CFS_LIST_HEAD(lu_device_types); int lu_device_type_init(struct lu_device_type *ldt) { int result; CFS_INIT_LIST_HEAD(&ldt->ldt_linkage); result = ldt->ldt_ops->ldto_init(ldt); if (result == 0) cfs_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) { cfs_list_del_init(&ldt->ldt_linkage); ldt->ldt_ops->ldto_fini(ldt); } EXPORT_SYMBOL(lu_device_type_fini); void lu_types_stop(void) { struct lu_device_type *ldt; cfs_list_for_each_entry(ldt, &lu_device_types, ldt_linkage) { if (ldt->ldt_device_nr == 0) ldt->ldt_ops->ldto_stop(ldt); } } EXPORT_SYMBOL(lu_types_stop); /** * Global list of all sites on this node */ static CFS_LIST_HEAD(lu_sites); static CFS_DECLARE_MUTEX(lu_sites_guard); /** * Global environment used by site shrinker. */ static struct lu_env lu_shrink_env; /** * 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) { int i; for (i = 0; i < s->ls_hash_size; ++i) { struct lu_object_header *h; cfs_hlist_node_t *scan; cfs_read_lock(&s->ls_guard); cfs_hlist_for_each_entry(h, scan, &s->ls_hash[i], loh_hash) { if (!cfs_list_empty(&h->loh_layers)) { const struct lu_object *obj; obj = lu_object_top(h); lu_object_print(env, cookie, printer, obj); } else lu_object_header_print(env, cookie, printer, h); } cfs_read_unlock(&s->ls_guard); } } EXPORT_SYMBOL(lu_site_print); enum { LU_CACHE_PERCENT = 20, }; /** * 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 = cfs_num_physpages; #if BITS_PER_LONG == 32 /* limit hashtable size for lowmem systems to low RAM */ if (cache_size > 1 << (30 - CFS_PAGE_SHIFT)) cache_size = 1 << (30 - CFS_PAGE_SHIFT) * 3 / 4; #endif cache_size = cache_size / 100 * LU_CACHE_PERCENT * (CFS_PAGE_SIZE / 1024); for (bits = 1; (1 << bits) < cache_size; ++bits) { ; } return bits; } static cfs_lock_class_key_t lu_site_guard_class; /** * Initialize site \a s, with \a d as the top level device. */ int lu_site_init(struct lu_site *s, struct lu_device *top) { int bits; int size; int i; ENTRY; memset(s, 0, sizeof *s); cfs_rwlock_init(&s->ls_guard); cfs_lockdep_set_class(&s->ls_guard, &lu_site_guard_class); CFS_INIT_LIST_HEAD(&s->ls_lru); CFS_INIT_LIST_HEAD(&s->ls_linkage); cfs_waitq_init(&s->ls_marche_funebre); s->ls_top_dev = top; top->ld_site = s; lu_device_get(top); lu_ref_add(&top->ld_reference, "site-top", s); for (bits = lu_htable_order(), size = 1 << bits; (s->ls_hash = cfs_alloc_large(size * sizeof s->ls_hash[0])) == NULL; --bits, size >>= 1) { /* * Scale hash table down, until allocation succeeds. */ ; } s->ls_hash_size = size; s->ls_hash_bits = bits; s->ls_hash_mask = size - 1; for (i = 0; i < size; i++) CFS_INIT_HLIST_HEAD(&s->ls_hash[i]); RETURN(0); } EXPORT_SYMBOL(lu_site_init); /** * Finalize \a s and release its resources. */ void lu_site_fini(struct lu_site *s) { LASSERT(cfs_list_empty(&s->ls_lru)); LASSERT(s->ls_total == 0); cfs_down(&lu_sites_guard); cfs_list_del_init(&s->ls_linkage); cfs_up(&lu_sites_guard); if (s->ls_hash != NULL) { int i; for (i = 0; i < s->ls_hash_size; i++) LASSERT(cfs_hlist_empty(&s->ls_hash[i])); cfs_free_large(s->ls_hash); s->ls_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; } } 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; cfs_down(&lu_sites_guard); result = lu_context_refill(&lu_shrink_env.le_ctx); if (result == 0) cfs_list_add(&s->ls_linkage, &lu_sites); cfs_up(&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) { cfs_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(cfs_atomic_read(&d->ld_ref) > 0); cfs_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); cfs_atomic_set(&d->ld_ref, 0); d->ld_type = t; lu_ref_init(&d->ld_reference); 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(cfs_atomic_read(&d->ld_ref) == 0, "Refcount is %u\n", cfs_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); CFS_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(cfs_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) { cfs_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) { cfs_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); cfs_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); 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(cfs_list_empty(&h->loh_layers)); LASSERT(cfs_list_empty(&h->loh_lru)); LASSERT(cfs_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; cfs_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); if (!cfs_list_empty(&site->ls_lru) || site->ls_total != 0) { /* * Uh-oh, objects still exist. */ static DECLARE_LU_CDEBUG_PRINT_INFO(cookie, D_ERROR); lu_site_print(env, site, &cookie, lu_cdebug_printer); } 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 = 32 }; static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, }; static cfs_spinlock_t lu_keys_guard = CFS_SPIN_LOCK_UNLOCKED; /** * 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; cfs_spin_lock(&lu_keys_guard); for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { if (lu_keys[i] == NULL) { key->lct_index = i; cfs_atomic_set(&key->lct_used, 1); lu_keys[i] = key; lu_ref_init(&key->lct_reference); result = 0; ++key_set_version; break; } } cfs_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(cfs_atomic_read(&key->lct_used) > 1); key->lct_fini(ctx, key, ctx->lc_value[index]); lu_ref_del(&key->lct_reference, "ctx", ctx); cfs_atomic_dec(&key->lct_used); LASSERT(key->lct_owner != NULL); if (!(ctx->lc_tags & LCT_NOREF)) { LASSERT(cfs_module_refcount(key->lct_owner) > 0); cfs_module_put(key->lct_owner); } ctx->lc_value[index] = NULL; } } /** * Deregister key. */ void lu_context_key_degister(struct lu_context_key *key) { LASSERT(cfs_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; cfs_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); } cfs_spin_unlock(&lu_keys_guard); LASSERTF(cfs_atomic_read(&key->lct_used) == 1, "key has instances: %d\n", cfs_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 CFS_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; extern unsigned cl_env_cache_purge(unsigned nr); if (!(key->lct_tags & LCT_QUIESCENT)) { /* * XXX layering violation. */ cl_env_cache_purge(~0); key->lct_tags |= LCT_QUIESCENT; /* * XXX memory barrier has to go here. */ cfs_spin_lock(&lu_keys_guard); cfs_list_for_each_entry(ctx, &lu_context_remembered, lc_remember) key_fini(ctx, key->lct_index); cfs_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; cfs_spin_lock(&lu_keys_guard); if (ctx->lc_value != NULL) { 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; } cfs_spin_unlock(&lu_keys_guard); } static int keys_fill(struct lu_context *ctx) { int i; 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)) cfs_try_module_get(key->lct_owner); lu_ref_add_atomic(&key->lct_reference, "ctx", ctx); cfs_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) { int result; OBD_ALLOC(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]); if (likely(ctx->lc_value != NULL)) result = keys_fill(ctx); else result = -ENOMEM; if (result != 0) keys_fini(ctx); return result; } /** * Initialize context data-structure. Create values for all keys. */ int lu_context_init(struct lu_context *ctx, __u32 tags) { memset(ctx, 0, sizeof *ctx); ctx->lc_state = LCS_INITIALIZED; ctx->lc_tags = tags; if (tags & LCT_REMEMBER) { cfs_spin_lock(&lu_keys_guard); cfs_list_add(&ctx->lc_remember, &lu_context_remembered); cfs_spin_unlock(&lu_keys_guard); } else CFS_INIT_LIST_HEAD(&ctx->lc_remember); return keys_init(ctx); } 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; keys_fini(ctx); cfs_spin_lock(&lu_keys_guard); cfs_list_del_init(&ctx->lc_remember); cfs_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. */ int lu_context_refill(struct lu_context *ctx) { LINVRNT(ctx->lc_value != NULL); return ctx->lc_version == key_set_version ? 0 : keys_fill(ctx); } EXPORT_SYMBOL(lu_context_refill); 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); static struct cfs_shrinker *lu_site_shrinker = NULL; #ifdef __KERNEL__ static int lu_cache_shrink(int nr, unsigned int gfp_mask) { struct lu_site *s; struct lu_site *tmp; int cached = 0; int remain = nr; CFS_LIST_HEAD(splice); if (nr != 0) { if (!(gfp_mask & __GFP_FS)) return -1; CDEBUG(D_INODE, "Shrink %d objects\n", nr); } cfs_down(&lu_sites_guard); cfs_list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) { if (nr != 0) { remain = lu_site_purge(&lu_shrink_env, s, remain); /* * Move just shrunk site to the tail of site list to * assure shrinking fairness. */ cfs_list_move_tail(&s->ls_linkage, &splice); } cfs_read_lock(&s->ls_guard); cached += s->ls_total - s->ls_busy; cfs_read_unlock(&s->ls_guard); if (nr && remain <= 0) break; } cfs_list_splice(&splice, lu_sites.prev); cfs_up(&lu_sites_guard); cached = (cached / 100) * sysctl_vfs_cache_pressure; if (nr == 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; } void lu_debugging_setup(void) { lu_env_init(&lu_debugging_env, ~0); } void lu_context_keys_dump(void) { int i; for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { struct lu_context_key *key; key = lu_keys[i]; if (key != NULL) { CERROR("[%i]: %p %x (%p,%p,%p) %i %i \"%s\"@%p\n", i, key, key->lct_tags, key->lct_init, key->lct_fini, key->lct_exit, key->lct_index, cfs_atomic_read(&key->lct_used), key->lct_owner ? key->lct_owner->name : "", key->lct_owner); lu_ref_print(&key->lct_reference); } } } EXPORT_SYMBOL(lu_context_keys_dump); #else /* !__KERNEL__ */ static int lu_cache_shrink(int nr, unsigned int gfp_mask) { return 0; } #endif /* __KERNEL__ */ int cl_global_init(void); void cl_global_fini(void); int lu_ref_global_init(void); void lu_ref_global_fini(void); int dt_global_init(void); void dt_global_fini(void); int llo_global_init(void); void llo_global_fini(void); /** * Initialization of global lu_* data. */ int lu_global_init(void) { int result; CDEBUG(D_CONSOLE, "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. */ cfs_down(&lu_sites_guard); result = lu_env_init(&lu_shrink_env, LCT_SHRINKER); cfs_up(&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 = cfs_set_shrinker(CFS_DEFAULT_SEEKS, lu_cache_shrink); if (lu_site_shrinker == NULL) return -ENOMEM; result = lu_time_global_init(); if (result) GOTO(out, result); #ifdef __KERNEL__ result = dt_global_init(); if (result) GOTO(out, result); result = llo_global_init(); if (result) GOTO(out, result); #endif result = cl_global_init(); out: return result; } /** * Dual to lu_global_init(). */ void lu_global_fini(void) { cl_global_fini(); #ifdef __KERNEL__ llo_global_fini(); dt_global_fini(); #endif lu_time_global_fini(); if (lu_site_shrinker != NULL) { cfs_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. */ cfs_down(&lu_sites_guard); lu_env_fini(&lu_shrink_env); cfs_up(&lu_sites_guard); lu_ref_global_fini(); } struct lu_buf LU_BUF_NULL = { .lb_buf = NULL, .lb_len = 0 }; EXPORT_SYMBOL(LU_BUF_NULL); /** * Output site statistical counters into a buffer. Suitable for * lprocfs_rd_*()-style functions. */ int lu_site_stats_print(const struct lu_site *s, char *page, int count) { int i; int populated; /* * How many hash buckets are not-empty? Don't bother with locks: it's * an estimation anyway. */ for (i = 0, populated = 0; i < s->ls_hash_size; i++) populated += !cfs_hlist_empty(&s->ls_hash[i]); return snprintf(page, count, "%d %d %d/%d %d %d %d %d %d %d %d\n", s->ls_total, s->ls_busy, populated, s->ls_hash_size, s->ls_stats.s_created, s->ls_stats.s_cache_hit, s->ls_stats.s_cache_miss, s->ls_stats.s_cache_check, s->ls_stats.s_cache_race, s->ls_stats.s_cache_death_race, s->ls_stats.s_lru_purged); } EXPORT_SYMBOL(lu_site_stats_print); const char *lu_time_names[LU_TIME_NR] = { [LU_TIME_FIND_LOOKUP] = "find_lookup", [LU_TIME_FIND_ALLOC] = "find_alloc", [LU_TIME_FIND_INSERT] = "find_insert" }; EXPORT_SYMBOL(lu_time_names); /** * Helper function to initialize a number of kmem slab caches at once. */ int lu_kmem_init(struct lu_kmem_descr *caches) { int result; for (result = 0; caches->ckd_cache != NULL; ++caches) { *caches->ckd_cache = cfs_mem_cache_create(caches->ckd_name, caches->ckd_size, 0, 0); if (*caches->ckd_cache == NULL) { result = -ENOMEM; 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) { int rc; for (; caches->ckd_cache != NULL; ++caches) { if (*caches->ckd_cache != NULL) { rc = cfs_mem_cache_destroy(*caches->ckd_cache); LASSERTF(rc == 0, "couldn't destroy %s slab\n", caches->ckd_name); *caches->ckd_cache = NULL; } } } EXPORT_SYMBOL(lu_kmem_fini);