-/* -*- 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.
*
* 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.
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
* GPL HEADER END
*/
/*
- * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
+ * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2014, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Client Extent Lock.
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
+ * Author: Jinshan Xiong <jinshan.xiong@intel.com>
*/
#define DEBUG_SUBSYSTEM S_CLASS
-#ifndef EXPORT_SYMTAB
-# define EXPORT_SYMTAB
-#endif
+#include <linux/list.h>
+#include <libcfs/libcfs.h>
#include <obd_class.h>
#include <obd_support.h>
#include <lustre_fid.h>
-#include <libcfs/list.h>
-/* lu_time_global_{init,fini}() */
-#include <lu_time.h>
-
#include <cl_object.h>
#include "cl_internal.h"
-/** Lock class of cl_lock::cll_guard */
-static struct lock_class_key cl_lock_guard_class;
-static cfs_mem_cache_t *cl_lock_kmem;
-
-static struct lu_kmem_descr cl_lock_caches[] = {
- {
- .ckd_cache = &cl_lock_kmem,
- .ckd_name = "cl_lock_kmem",
- .ckd_size = sizeof (struct cl_lock)
- },
- {
- .ckd_cache = NULL
- }
-};
-
-/**
- * Basic lock invariant that is maintained at all times. Caller either has a
- * reference to \a lock, or somehow assures that \a lock cannot be freed.
- *
- * \see cl_lock_invariant()
- */
-static int cl_lock_invariant_trusted(const struct lu_env *env,
- const struct cl_lock *lock)
-{
- return
- cl_is_lock(lock) &&
- ergo(lock->cll_state == CLS_FREEING, lock->cll_holds == 0) &&
- atomic_read(&lock->cll_ref) >= lock->cll_holds &&
- lock->cll_holds >= lock->cll_users &&
- lock->cll_holds >= 0 &&
- lock->cll_users >= 0 &&
- lock->cll_depth >= 0;
-}
-
-/**
- * Stronger lock invariant, checking that caller has a reference on a lock.
- *
- * \see cl_lock_invariant_trusted()
- */
-static int cl_lock_invariant(const struct lu_env *env,
- const struct cl_lock *lock)
-{
- int result;
-
- result = atomic_read(&lock->cll_ref) > 0 &&
- cl_lock_invariant_trusted(env, lock);
- if (!result && env != NULL)
- CL_LOCK_DEBUG(D_ERROR, env, lock, "invariant broken");
- return result;
-}
-
-/**
- * Returns lock "nesting": 0 for a top-lock and 1 for a sub-lock.
- */
-static enum clt_nesting_level cl_lock_nesting(const struct cl_lock *lock)
-{
- return cl_object_header(lock->cll_descr.cld_obj)->coh_nesting;
-}
-
-/**
- * Returns a set of counters for this lock, depending on a lock nesting.
- */
-static struct cl_thread_counters *cl_lock_counters(const struct lu_env *env,
- const struct cl_lock *lock)
-{
- struct cl_thread_info *info;
- enum clt_nesting_level nesting;
-
- info = cl_env_info(env);
- nesting = cl_lock_nesting(lock);
- LASSERT(nesting < ARRAY_SIZE(info->clt_counters));
- return &info->clt_counters[nesting];
-}
-
-#define RETIP ((unsigned long)__builtin_return_address(0))
-
-#ifdef CONFIG_LOCKDEP
-static struct lock_class_key cl_lock_key;
-
-static void cl_lock_lockdep_init(struct cl_lock *lock)
-{
- lockdep_set_class_and_name(lock, &cl_lock_key, "EXT");
-}
-
-static void cl_lock_lockdep_acquire(const struct lu_env *env,
- struct cl_lock *lock, __u32 enqflags)
+static void cl_lock_trace0(int level, const struct lu_env *env,
+ const char *prefix, const struct cl_lock *lock,
+ const char *func, const int line)
{
- cl_lock_counters(env, lock)->ctc_nr_locks_acquired++;
- lock_acquire(&lock->dep_map, !!(enqflags & CEF_ASYNC),
- /* try: */ 0, lock->cll_descr.cld_mode <= CLM_READ,
- /* check: */ 2, RETIP);
+ struct cl_object_header *h = cl_object_header(lock->cll_descr.cld_obj);
+ CDEBUG(level, "%s: %p (%p/%d) at %s():%d\n",
+ prefix, lock, env, h->coh_nesting, func, line);
}
-
-static void cl_lock_lockdep_release(const struct lu_env *env,
- struct cl_lock *lock)
-{
- cl_lock_counters(env, lock)->ctc_nr_locks_acquired--;
- lock_release(&lock->dep_map, 0, RETIP);
-}
-
-#else /* !CONFIG_LOCKDEP */
-
-static void cl_lock_lockdep_init(struct cl_lock *lock)
-{}
-static void cl_lock_lockdep_acquire(const struct lu_env *env,
- struct cl_lock *lock, __u32 enqflags)
-{}
-static void cl_lock_lockdep_release(const struct lu_env *env,
- struct cl_lock *lock)
-{}
-
-#endif /* !CONFIG_LOCKDEP */
+#define cl_lock_trace(level, env, prefix, lock) \
+ cl_lock_trace0(level, env, prefix, lock, __FUNCTION__, __LINE__)
/**
* Adds lock slice to the compound lock.
struct cl_object *obj,
const struct cl_lock_operations *ops)
{
- ENTRY;
- slice->cls_lock = lock;
- list_add_tail(&slice->cls_linkage, &lock->cll_layers);
- slice->cls_obj = obj;
- slice->cls_ops = ops;
- EXIT;
+ ENTRY;
+ slice->cls_lock = lock;
+ list_add_tail(&slice->cls_linkage, &lock->cll_layers);
+ slice->cls_obj = obj;
+ slice->cls_ops = ops;
+ EXIT;
}
EXPORT_SYMBOL(cl_lock_slice_add);
-/**
- * Returns true iff a lock with the mode \a has provides at least the same
- * guarantees as a lock with the mode \a need.
- */
-int cl_lock_mode_match(enum cl_lock_mode has, enum cl_lock_mode need)
-{
- LINVRNT(need == CLM_READ || need == CLM_WRITE ||
- need == CLM_PHANTOM || need == CLM_GROUP);
- LINVRNT(has == CLM_READ || has == CLM_WRITE ||
- has == CLM_PHANTOM || has == CLM_GROUP);
- CLASSERT(CLM_PHANTOM < CLM_READ);
- CLASSERT(CLM_READ < CLM_WRITE);
- CLASSERT(CLM_WRITE < CLM_GROUP);
-
- if (has != CLM_GROUP)
- return need <= has;
- else
- return need == has;
-}
-EXPORT_SYMBOL(cl_lock_mode_match);
-
-/**
- * Returns true iff extent portions of lock descriptions match.
- */
-int cl_lock_ext_match(const struct cl_lock_descr *has,
- const struct cl_lock_descr *need)
-{
- return
- has->cld_start <= need->cld_start &&
- has->cld_end >= need->cld_end &&
- cl_lock_mode_match(has->cld_mode, need->cld_mode) &&
- (has->cld_mode != CLM_GROUP || has->cld_gid == need->cld_gid);
-}
-EXPORT_SYMBOL(cl_lock_ext_match);
-
-/**
- * Returns true iff a lock with the description \a has provides at least the
- * same guarantees as a lock with the description \a need.
- */
-int cl_lock_descr_match(const struct cl_lock_descr *has,
- const struct cl_lock_descr *need)
-{
- return
- cl_object_same(has->cld_obj, need->cld_obj) &&
- cl_lock_ext_match(has, need);
-}
-EXPORT_SYMBOL(cl_lock_descr_match);
-
-static void cl_lock_free(const struct lu_env *env, struct cl_lock *lock)
-{
- struct cl_object *obj = lock->cll_descr.cld_obj;
-
- LASSERT(cl_is_lock(lock));
- LINVRNT(!cl_lock_is_mutexed(lock));
-
- ENTRY;
- might_sleep();
- while (!list_empty(&lock->cll_layers)) {
- struct cl_lock_slice *slice;
-
- slice = list_entry(lock->cll_layers.next, struct cl_lock_slice,
- cls_linkage);
- list_del_init(lock->cll_layers.next);
- slice->cls_ops->clo_fini(env, slice);
- }
- atomic_dec(&cl_object_site(obj)->cs_locks.cs_total);
- atomic_dec(&cl_object_site(obj)->cs_locks_state[lock->cll_state]);
- lu_object_ref_del_at(&obj->co_lu, lock->cll_obj_ref, "cl_lock", lock);
- cl_object_put(env, obj);
- lu_ref_fini(&lock->cll_reference);
- lu_ref_fini(&lock->cll_holders);
- mutex_destroy(&lock->cll_guard);
- OBD_SLAB_FREE_PTR(lock, cl_lock_kmem);
- EXIT;
-}
-
-/**
- * Releases a reference on a lock.
- *
- * When last reference is released, lock is returned to the cache, unless it
- * is in cl_lock_state::CLS_FREEING state, in which case it is destroyed
- * immediately.
- *
- * \see cl_object_put(), cl_page_put()
- */
-void cl_lock_put(const struct lu_env *env, struct cl_lock *lock)
-{
- struct cl_object *obj;
- struct cl_object_header *head;
- struct cl_site *site;
-
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
- obj = lock->cll_descr.cld_obj;
- LINVRNT(obj != NULL);
- head = cl_object_header(obj);
- site = cl_object_site(obj);
-
- CDEBUG(D_TRACE, "releasing reference: %d %p %lu\n",
- atomic_read(&lock->cll_ref), lock, RETIP);
-
- if (atomic_dec_and_test(&lock->cll_ref)) {
- if (lock->cll_state == CLS_FREEING) {
- LASSERT(list_empty(&lock->cll_linkage));
- cl_lock_free(env, lock);
- }
- atomic_dec(&site->cs_locks.cs_busy);
- }
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_put);
-
-/**
- * Acquires an additional reference to a lock.
- *
- * This can be called only by caller already possessing a reference to \a
- * lock.
- *
- * \see cl_object_get(), cl_page_get()
- */
-void cl_lock_get(struct cl_lock *lock)
-{
- LINVRNT(cl_lock_invariant(NULL, lock));
- CDEBUG(D_TRACE, "acquiring reference: %d %p %lu\n",
- atomic_read(&lock->cll_ref), lock, RETIP);
- atomic_inc(&lock->cll_ref);
-}
-EXPORT_SYMBOL(cl_lock_get);
-
-/**
- * Acquires a reference to a lock.
- *
- * This is much like cl_lock_get(), except that this function can be used to
- * acquire initial reference to the cached lock. Caller has to deal with all
- * possible races. Use with care!
- *
- * \see cl_page_get_trust()
- */
-void cl_lock_get_trust(struct cl_lock *lock)
-{
- struct cl_site *site = cl_object_site(lock->cll_descr.cld_obj);
-
- LASSERT(cl_is_lock(lock));
- CDEBUG(D_TRACE, "acquiring trusted reference: %d %p %lu\n",
- atomic_read(&lock->cll_ref), lock, RETIP);
- if (atomic_inc_return(&lock->cll_ref) == 1)
- atomic_inc(&site->cs_locks.cs_busy);
-}
-EXPORT_SYMBOL(cl_lock_get_trust);
-
-/**
- * Helper function destroying the lock that wasn't completely initialized.
- *
- * Other threads can acquire references to the top-lock through its
- * sub-locks. Hence, it cannot be cl_lock_free()-ed immediately.
- */
-static void cl_lock_finish(const struct lu_env *env, struct cl_lock *lock)
-{
- cl_lock_mutex_get(env, lock);
- cl_lock_delete(env, lock);
- cl_lock_mutex_put(env, lock);
- cl_lock_put(env, lock);
-}
-
-static struct cl_lock *cl_lock_alloc(const struct lu_env *env,
- struct cl_object *obj,
- const struct cl_io *io,
- const struct cl_lock_descr *descr)
-{
- struct cl_lock *lock;
- struct lu_object_header *head;
- struct cl_site *site = cl_object_site(obj);
-
- ENTRY;
- OBD_SLAB_ALLOC_PTR_GFP(lock, cl_lock_kmem, CFS_ALLOC_IO);
- if (lock != NULL) {
- atomic_set(&lock->cll_ref, 1);
- lock->cll_descr = *descr;
- lock->cll_state = CLS_NEW;
- cl_object_get(obj);
- lock->cll_obj_ref = lu_object_ref_add(&obj->co_lu,
- "cl_lock", lock);
- CFS_INIT_LIST_HEAD(&lock->cll_layers);
- CFS_INIT_LIST_HEAD(&lock->cll_linkage);
- CFS_INIT_LIST_HEAD(&lock->cll_inclosure);
- lu_ref_init(&lock->cll_reference);
- lu_ref_init(&lock->cll_holders);
- mutex_init(&lock->cll_guard);
- lockdep_set_class(&lock->cll_guard, &cl_lock_guard_class);
- cfs_waitq_init(&lock->cll_wq);
- head = obj->co_lu.lo_header;
- atomic_inc(&site->cs_locks_state[CLS_NEW]);
- atomic_inc(&site->cs_locks.cs_total);
- atomic_inc(&site->cs_locks.cs_created);
- cl_lock_lockdep_init(lock);
- list_for_each_entry(obj, &head->loh_layers, co_lu.lo_linkage) {
- int err;
-
- err = obj->co_ops->coo_lock_init(env, obj, lock, io);
- if (err != 0) {
- cl_lock_finish(env, lock);
- lock = ERR_PTR(err);
- break;
- }
- }
- } else
- lock = ERR_PTR(-ENOMEM);
- RETURN(lock);
-}
-
-/**
- * Transfer the lock into INTRANSIT state and return the original state.
- *
- * \pre state: CLS_CACHED, CLS_HELD or CLS_ENQUEUED
- * \post state: CLS_INTRANSIT
- * \see CLS_INTRANSIT
- */
-enum cl_lock_state cl_lock_intransit(const struct lu_env *env,
- struct cl_lock *lock)
-{
- enum cl_lock_state state = lock->cll_state;
-
- LASSERT(cl_lock_is_mutexed(lock));
- LASSERT(state != CLS_INTRANSIT);
- LASSERTF(state >= CLS_ENQUEUED && state <= CLS_CACHED,
- "Malformed lock state %d.\n", state);
-
- cl_lock_state_set(env, lock, CLS_INTRANSIT);
- lock->cll_intransit_owner = cfs_current();
- cl_lock_hold_add(env, lock, "intransit", cfs_current());
- return state;
-}
-EXPORT_SYMBOL(cl_lock_intransit);
-
-/**
- * Exit the intransit state and restore the lock state to the original state
- */
-void cl_lock_extransit(const struct lu_env *env, struct cl_lock *lock,
- enum cl_lock_state state)
-{
- LASSERT(cl_lock_is_mutexed(lock));
- LASSERT(lock->cll_state == CLS_INTRANSIT);
- LASSERT(state != CLS_INTRANSIT);
- LASSERT(lock->cll_intransit_owner == cfs_current());
-
- lock->cll_intransit_owner = NULL;
- cl_lock_state_set(env, lock, state);
- cl_lock_unhold(env, lock, "intransit", cfs_current());
-}
-EXPORT_SYMBOL(cl_lock_extransit);
-
-/**
- * Checking whether the lock is intransit state
- */
-int cl_lock_is_intransit(struct cl_lock *lock)
-{
- LASSERT(cl_lock_is_mutexed(lock));
- return lock->cll_state == CLS_INTRANSIT &&
- lock->cll_intransit_owner != cfs_current();
-}
-EXPORT_SYMBOL(cl_lock_is_intransit);
-/**
- * Returns true iff lock is "suitable" for given io. E.g., locks acquired by
- * truncate and O_APPEND cannot be reused for read/non-append-write, as they
- * cover multiple stripes and can trigger cascading timeouts.
- */
-static int cl_lock_fits_into(const struct lu_env *env,
- const struct cl_lock *lock,
- const struct cl_lock_descr *need,
- const struct cl_io *io)
-{
- const struct cl_lock_slice *slice;
-
- LINVRNT(cl_lock_invariant_trusted(env, lock));
- ENTRY;
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_fits_into != NULL &&
- !slice->cls_ops->clo_fits_into(env, slice, need, io))
- RETURN(0);
- }
- RETURN(1);
-}
-
-static struct cl_lock *cl_lock_lookup(const struct lu_env *env,
- struct cl_object *obj,
- const struct cl_io *io,
- const struct cl_lock_descr *need)
-{
- struct cl_lock *lock;
- struct cl_object_header *head;
- struct cl_site *site;
-
- ENTRY;
-
- head = cl_object_header(obj);
- site = cl_object_site(obj);
- LINVRNT_SPIN_LOCKED(&head->coh_lock_guard);
- atomic_inc(&site->cs_locks.cs_lookup);
- list_for_each_entry(lock, &head->coh_locks, cll_linkage) {
- int matched;
-
- LASSERT(cl_is_lock(lock));
- matched = cl_lock_ext_match(&lock->cll_descr, need) &&
- lock->cll_state < CLS_FREEING &&
- !(lock->cll_flags & CLF_CANCELLED) &&
- cl_lock_fits_into(env, lock, need, io);
- CDEBUG(D_DLMTRACE, "has: "DDESCR"(%i) need: "DDESCR": %d\n",
- PDESCR(&lock->cll_descr), lock->cll_state, PDESCR(need),
- matched);
- if (matched) {
- cl_lock_get_trust(lock);
- /* move the lock to the LRU head */
- list_move(&lock->cll_linkage, &head->coh_locks);
- atomic_inc(&cl_object_site(obj)->cs_locks.cs_hit);
- RETURN(lock);
- }
- }
- RETURN(NULL);
-}
-
-/**
- * Returns a lock matching description \a need.
- *
- * This is the main entry point into the cl_lock caching interface. First, a
- * cache (implemented as a per-object linked list) is consulted. If lock is
- * found there, it is returned immediately. Otherwise new lock is allocated
- * and returned. In any case, additional reference to lock is acquired.
- *
- * \see cl_object_find(), cl_page_find()
- */
-static struct cl_lock *cl_lock_find(const struct lu_env *env,
- const struct cl_io *io,
- const struct cl_lock_descr *need)
+void cl_lock_fini(const struct lu_env *env, struct cl_lock *lock)
{
- struct cl_object_header *head;
- struct cl_object *obj;
- struct cl_lock *lock;
- struct cl_site *site;
-
- ENTRY;
-
- obj = need->cld_obj;
- head = cl_object_header(obj);
- site = cl_object_site(obj);
+ ENTRY;
- spin_lock(&head->coh_lock_guard);
- lock = cl_lock_lookup(env, obj, io, need);
- spin_unlock(&head->coh_lock_guard);
+ cl_lock_trace(D_DLMTRACE, env, "destroy lock", lock);
- if (lock == NULL) {
- lock = cl_lock_alloc(env, obj, io, need);
- if (!IS_ERR(lock)) {
- struct cl_lock *ghost;
+ while (!list_empty(&lock->cll_layers)) {
+ struct cl_lock_slice *slice;
- spin_lock(&head->coh_lock_guard);
- ghost = cl_lock_lookup(env, obj, io, need);
- if (ghost == NULL) {
- list_add(&lock->cll_linkage, &head->coh_locks);
- spin_unlock(&head->coh_lock_guard);
- atomic_inc(&site->cs_locks.cs_busy);
- } else {
- spin_unlock(&head->coh_lock_guard);
- /*
- * Other threads can acquire references to the
- * top-lock through its sub-locks. Hence, it
- * cannot be cl_lock_free()-ed immediately.
- */
- cl_lock_finish(env, lock);
- lock = ghost;
- }
- }
- }
- RETURN(lock);
+ slice = list_entry(lock->cll_layers.next,
+ struct cl_lock_slice, cls_linkage);
+ list_del_init(lock->cll_layers.next);
+ slice->cls_ops->clo_fini(env, slice);
+ }
+ POISON(lock, 0x5a, sizeof(*lock));
+ EXIT;
}
+EXPORT_SYMBOL(cl_lock_fini);
-/**
- * Returns existing lock matching given description. This is similar to
- * cl_lock_find() except that no new lock is created, and returned lock is
- * guaranteed to be in enum cl_lock_state::CLS_HELD state.
- */
-struct cl_lock *cl_lock_peek(const struct lu_env *env, const struct cl_io *io,
- const struct cl_lock_descr *need,
- const char *scope, const void *source)
+int cl_lock_init(const struct lu_env *env, struct cl_lock *lock,
+ const struct cl_io *io)
{
- struct cl_object_header *head;
- struct cl_object *obj;
- struct cl_lock *lock;
- int ok;
-
- obj = need->cld_obj;
- head = cl_object_header(obj);
-
- spin_lock(&head->coh_lock_guard);
- lock = cl_lock_lookup(env, obj, io, need);
- spin_unlock(&head->coh_lock_guard);
+ struct cl_object *obj = lock->cll_descr.cld_obj;
+ struct cl_object *scan;
+ int result = 0;
+ ENTRY;
- if (lock == NULL)
- return NULL;
+ /* Make sure cl_lock::cll_descr is initialized. */
+ LASSERT(obj != NULL);
- cl_lock_mutex_get(env, lock);
- if (lock->cll_state == CLS_INTRANSIT)
- cl_lock_state_wait(env, lock); /* Don't care return value. */
- if (lock->cll_state == CLS_CACHED) {
- int result;
- result = cl_use_try(env, lock, 1);
- if (result < 0)
- cl_lock_error(env, lock, result);
- }
- ok = lock->cll_state == CLS_HELD;
- if (ok) {
- cl_lock_hold_add(env, lock, scope, source);
- cl_lock_user_add(env, lock);
- cl_lock_put(env, lock);
- }
- cl_lock_mutex_put(env, lock);
- if (!ok) {
- cl_lock_put(env, lock);
- lock = NULL;
- }
-
- return lock;
+ INIT_LIST_HEAD(&lock->cll_layers);
+ list_for_each_entry(scan, &obj->co_lu.lo_header->loh_layers,
+ co_lu.lo_linkage) {
+ result = scan->co_ops->coo_lock_init(env, scan, lock, io);
+ if (result != 0) {
+ cl_lock_fini(env, lock);
+ break;
+ }
+ }
+ RETURN(result);
}
-EXPORT_SYMBOL(cl_lock_peek);
+EXPORT_SYMBOL(cl_lock_init);
/**
- * Returns a slice within a lock, corresponding to the given layer in the
+ * Returns a slice with a lock, corresponding to the given layer in the
* device stack.
*
* \see cl_page_at()
*/
const struct cl_lock_slice *cl_lock_at(const struct cl_lock *lock,
- const struct lu_device_type *dtype)
+ const struct lu_device_type *dtype)
{
- const struct cl_lock_slice *slice;
+ const struct cl_lock_slice *slice;
- LINVRNT(cl_lock_invariant_trusted(NULL, lock));
- ENTRY;
+ ENTRY;
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_obj->co_lu.lo_dev->ld_type == dtype)
- RETURN(slice);
- }
- RETURN(NULL);
+ list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
+ if (slice->cls_obj->co_lu.lo_dev->ld_type == dtype)
+ RETURN(slice);
+ }
+ RETURN(NULL);
}
EXPORT_SYMBOL(cl_lock_at);
-static void cl_lock_trace(struct cl_thread_counters *counters,
- const char *prefix, const struct cl_lock *lock)
-{
- CDEBUG(D_DLMTRACE|D_TRACE, "%s: %i@%p %p %i %i\n", prefix,
- atomic_read(&lock->cll_ref), lock, lock->cll_guarder,
- lock->cll_depth, counters->ctc_nr_locks_locked);
-}
-
-static void cl_lock_mutex_tail(const struct lu_env *env, struct cl_lock *lock)
-{
- struct cl_thread_counters *counters;
-
- counters = cl_lock_counters(env, lock);
- lock->cll_depth++;
- counters->ctc_nr_locks_locked++;
- lu_ref_add(&counters->ctc_locks_locked, "cll_guard", lock);
- cl_lock_trace(counters, "got mutex", lock);
-}
-
-/**
- * Locks cl_lock object.
- *
- * This is used to manipulate cl_lock fields, and to serialize state
- * transitions in the lock state machine.
- *
- * \post cl_lock_is_mutexed(lock)
- *
- * \see cl_lock_mutex_put()
- */
-void cl_lock_mutex_get(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_invariant(env, lock));
-
- if (lock->cll_guarder == cfs_current()) {
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(lock->cll_depth > 0);
- } else {
- struct cl_object_header *hdr;
- struct cl_thread_info *info;
- int i;
-
- LINVRNT(lock->cll_guarder != cfs_current());
- hdr = cl_object_header(lock->cll_descr.cld_obj);
- /*
- * Check that mutices are taken in the bottom-to-top order.
- */
- info = cl_env_info(env);
- for (i = 0; i < hdr->coh_nesting; ++i)
- LASSERT(info->clt_counters[i].ctc_nr_locks_locked == 0);
- mutex_lock_nested(&lock->cll_guard, hdr->coh_nesting);
- lock->cll_guarder = cfs_current();
- LINVRNT(lock->cll_depth == 0);
- }
- cl_lock_mutex_tail(env, lock);
-}
-EXPORT_SYMBOL(cl_lock_mutex_get);
-
-/**
- * Try-locks cl_lock object.
- *
- * \retval 0 \a lock was successfully locked
- *
- * \retval -EBUSY \a lock cannot be locked right now
- *
- * \post ergo(result == 0, cl_lock_is_mutexed(lock))
- *
- * \see cl_lock_mutex_get()
- */
-int cl_lock_mutex_try(const struct lu_env *env, struct cl_lock *lock)
+void cl_lock_cancel(const struct lu_env *env, struct cl_lock *lock)
{
- int result;
+ const struct cl_lock_slice *slice;
+ ENTRY;
- LINVRNT(cl_lock_invariant_trusted(env, lock));
- ENTRY;
+ cl_lock_trace(D_DLMTRACE, env, "cancel lock", lock);
+ list_for_each_entry_reverse(slice, &lock->cll_layers, cls_linkage) {
+ if (slice->cls_ops->clo_cancel != NULL)
+ slice->cls_ops->clo_cancel(env, slice);
+ }
- result = 0;
- if (lock->cll_guarder == cfs_current()) {
- LINVRNT(lock->cll_depth > 0);
- cl_lock_mutex_tail(env, lock);
- } else if (mutex_trylock(&lock->cll_guard)) {
- LINVRNT(lock->cll_depth == 0);
- lock->cll_guarder = cfs_current();
- cl_lock_mutex_tail(env, lock);
- } else
- result = -EBUSY;
- RETURN(result);
+ EXIT;
}
-EXPORT_SYMBOL(cl_lock_mutex_try);
+EXPORT_SYMBOL(cl_lock_cancel);
/**
- {* Unlocks cl_lock object.
- *
- * \pre cl_lock_is_mutexed(lock)
- *
- * \see cl_lock_mutex_get()
+ * Enqueue a lock.
+ * \param anchor: if we need to wait for resources before getting the lock,
+ * use @anchor for the purpose.
+ * \retval 0 enqueue successfully
+ * \retval <0 error code
*/
-void cl_lock_mutex_put(const struct lu_env *env, struct cl_lock *lock)
+int cl_lock_enqueue(const struct lu_env *env, struct cl_io *io,
+ struct cl_lock *lock, struct cl_sync_io *anchor)
{
- struct cl_thread_counters *counters;
+ const struct cl_lock_slice *slice;
+ int rc = -ENOSYS;
- LINVRNT(cl_lock_invariant(env, lock));
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(lock->cll_guarder == cfs_current());
- LINVRNT(lock->cll_depth > 0);
+ ENTRY;
- counters = cl_lock_counters(env, lock);
- LINVRNT(counters->ctc_nr_locks_locked > 0);
+ list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
+ if (slice->cls_ops->clo_enqueue == NULL)
+ continue;
- cl_lock_trace(counters, "put mutex", lock);
- lu_ref_del(&counters->ctc_locks_locked, "cll_guard", lock);
- counters->ctc_nr_locks_locked--;
- if (--lock->cll_depth == 0) {
- lock->cll_guarder = NULL;
- mutex_unlock(&lock->cll_guard);
- }
+ rc = slice->cls_ops->clo_enqueue(env, slice, io, anchor);
+ if (rc != 0)
+ break;
+ }
+ RETURN(rc);
}
-EXPORT_SYMBOL(cl_lock_mutex_put);
+EXPORT_SYMBOL(cl_lock_enqueue);
/**
- * Returns true iff lock's mutex is owned by the current thread.
- */
-int cl_lock_is_mutexed(struct cl_lock *lock)
-{
- return lock->cll_guarder == cfs_current();
-}
-EXPORT_SYMBOL(cl_lock_is_mutexed);
-
-/**
- * Returns number of cl_lock mutices held by the current thread (environment).
+ * Main high-level entry point of cl_lock interface that finds existing or
+ * enqueues new lock matching given description.
*/
-int cl_lock_nr_mutexed(const struct lu_env *env)
-{
- struct cl_thread_info *info;
- int i;
- int locked;
-
- /*
- * NOTE: if summation across all nesting levels (currently 2) proves
- * too expensive, a summary counter can be added to
- * struct cl_thread_info.
- */
- info = cl_env_info(env);
- for (i = 0, locked = 0; i < ARRAY_SIZE(info->clt_counters); ++i)
- locked += info->clt_counters[i].ctc_nr_locks_locked;
- return locked;
-}
-EXPORT_SYMBOL(cl_lock_nr_mutexed);
-
-static void cl_lock_cancel0(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
- if (!(lock->cll_flags & CLF_CANCELLED)) {
- const struct cl_lock_slice *slice;
-
- lock->cll_flags |= CLF_CANCELLED;
- list_for_each_entry_reverse(slice, &lock->cll_layers,
- cls_linkage) {
- if (slice->cls_ops->clo_cancel != NULL)
- slice->cls_ops->clo_cancel(env, slice);
- }
- }
- EXIT;
-}
-
-static void cl_lock_delete0(const struct lu_env *env, struct cl_lock *lock)
+int cl_lock_request(const struct lu_env *env, struct cl_io *io,
+ struct cl_lock *lock)
{
- struct cl_object_header *head;
- const struct cl_lock_slice *slice;
-
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
+ struct cl_sync_io *anchor = NULL;
+ __u32 enq_flags = lock->cll_descr.cld_enq_flags;
+ int rc;
+ ENTRY;
- ENTRY;
- if (lock->cll_state < CLS_FREEING) {
- cl_lock_state_set(env, lock, CLS_FREEING);
-
- head = cl_object_header(lock->cll_descr.cld_obj);
-
- spin_lock(&head->coh_lock_guard);
- list_del_init(&lock->cll_linkage);
-
- spin_unlock(&head->coh_lock_guard);
- /*
- * From now on, no new references to this lock can be acquired
- * by cl_lock_lookup().
- */
- list_for_each_entry_reverse(slice, &lock->cll_layers,
- cls_linkage) {
- if (slice->cls_ops->clo_delete != NULL)
- slice->cls_ops->clo_delete(env, slice);
- }
- /*
- * From now on, no new references to this lock can be acquired
- * by layer-specific means (like a pointer from struct
- * ldlm_lock in osc, or a pointer from top-lock to sub-lock in
- * lov).
- *
- * Lock will be finally freed in cl_lock_put() when last of
- * existing references goes away.
- */
- }
- EXIT;
-}
-
-/**
- * Mod(ifie)s cl_lock::cll_holds counter for a given lock. Also, for a
- * top-lock (nesting == 0) accounts for this modification in the per-thread
- * debugging counters. Sub-lock holds can be released by a thread different
- * from one that acquired it.
- */
-static void cl_lock_hold_mod(const struct lu_env *env, struct cl_lock *lock,
- int delta)
-{
- struct cl_thread_counters *counters;
- enum clt_nesting_level nesting;
+ rc = cl_lock_init(env, lock, io);
+ if (rc < 0)
+ RETURN(rc);
- lock->cll_holds += delta;
- nesting = cl_lock_nesting(lock);
- if (nesting == CNL_TOP) {
- counters = &cl_env_info(env)->clt_counters[CNL_TOP];
- counters->ctc_nr_held += delta;
- LASSERT(counters->ctc_nr_held >= 0);
- }
-}
+ if ((enq_flags & CEF_GLIMPSE) && !(enq_flags & CEF_SPECULATIVE)) {
+ anchor = &cl_env_info(env)->clt_anchor;
+ cl_sync_io_init(anchor, 1, cl_sync_io_end);
+ }
-/**
- * Mod(ifie)s cl_lock::cll_users counter for a given lock. See
- * cl_lock_hold_mod() for the explanation of the debugging code.
- */
-static void cl_lock_used_mod(const struct lu_env *env, struct cl_lock *lock,
- int delta)
-{
- struct cl_thread_counters *counters;
- enum clt_nesting_level nesting;
+ rc = cl_lock_enqueue(env, io, lock, anchor);
- lock->cll_users += delta;
- nesting = cl_lock_nesting(lock);
- if (nesting == CNL_TOP) {
- counters = &cl_env_info(env)->clt_counters[CNL_TOP];
- counters->ctc_nr_used += delta;
- LASSERT(counters->ctc_nr_used >= 0);
- }
-}
+ if (anchor != NULL) {
+ int rc2;
-static void cl_lock_hold_release(const struct lu_env *env, struct cl_lock *lock,
- const char *scope, const void *source)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_holds > 0);
+ /* drop the reference count held at initialization time */
+ cl_sync_io_note(env, anchor, 0);
+ rc2 = cl_sync_io_wait(env, anchor, 0);
+ if (rc2 < 0 && rc == 0)
+ rc = rc2;
+ }
- ENTRY;
- lu_ref_del(&lock->cll_holders, scope, source);
- cl_lock_hold_mod(env, lock, -1);
- if (lock->cll_holds == 0) {
- if (lock->cll_descr.cld_mode == CLM_PHANTOM ||
- lock->cll_descr.cld_mode == CLM_GROUP)
- /*
- * If lock is still phantom or grouplock when user is
- * done with it---destroy the lock.
- */
- lock->cll_flags |= CLF_CANCELPEND|CLF_DOOMED;
- if (lock->cll_flags & CLF_CANCELPEND) {
- lock->cll_flags &= ~CLF_CANCELPEND;
- cl_lock_cancel0(env, lock);
- }
- if (lock->cll_flags & CLF_DOOMED) {
- /* no longer doomed: it's dead... Jim. */
- lock->cll_flags &= ~CLF_DOOMED;
- cl_lock_delete0(env, lock);
- }
- }
- EXIT;
+ if (rc < 0)
+ cl_lock_release(env, lock);
+ RETURN(rc);
}
-
+EXPORT_SYMBOL(cl_lock_request);
/**
- * Waits until lock state is changed.
- *
- * This function is called with cl_lock mutex locked, atomically releases
- * mutex and goes to sleep, waiting for a lock state change (signaled by
- * cl_lock_signal()), and re-acquires the mutex before return.
- *
- * This function is used to wait until lock state machine makes some progress
- * and to emulate synchronous operations on top of asynchronous lock
- * interface.
- *
- * \retval -EINTR wait was interrupted
- *
- * \retval 0 wait wasn't interrupted
- *
- * \pre cl_lock_is_mutexed(lock)
- *
- * \see cl_lock_signal()
+ * Releases a hold and a reference on a lock, obtained by cl_lock_hold().
*/
-int cl_lock_state_wait(const struct lu_env *env, struct cl_lock *lock)
-{
- cfs_waitlink_t waiter;
- int result;
-
- ENTRY;
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_depth == 1);
- LASSERT(lock->cll_state != CLS_FREEING); /* too late to wait */
-
- result = lock->cll_error;
- if (result == 0) {
- cfs_waitlink_init(&waiter);
- cfs_waitq_add(&lock->cll_wq, &waiter);
- set_current_state(CFS_TASK_INTERRUPTIBLE);
- cl_lock_mutex_put(env, lock);
-
- LASSERT(cl_lock_nr_mutexed(env) == 0);
- cfs_waitq_wait(&waiter, CFS_TASK_INTERRUPTIBLE);
-
- cl_lock_mutex_get(env, lock);
- set_current_state(CFS_TASK_RUNNING);
- cfs_waitq_del(&lock->cll_wq, &waiter);
- result = cfs_signal_pending() ? -EINTR : 0;
- }
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_lock_state_wait);
-
-static void cl_lock_state_signal(const struct lu_env *env, struct cl_lock *lock,
- enum cl_lock_state state)
+void cl_lock_release(const struct lu_env *env, struct cl_lock *lock)
{
- const struct cl_lock_slice *slice;
+ ENTRY;
- ENTRY;
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage)
- if (slice->cls_ops->clo_state != NULL)
- slice->cls_ops->clo_state(env, slice, state);
- cfs_waitq_broadcast(&lock->cll_wq);
- EXIT;
+ cl_lock_trace(D_DLMTRACE, env, "release lock", lock);
+ cl_lock_cancel(env, lock);
+ cl_lock_fini(env, lock);
+ EXIT;
}
+EXPORT_SYMBOL(cl_lock_release);
-/**
- * Notifies waiters that lock state changed.
- *
- * Wakes up all waiters sleeping in cl_lock_state_wait(), also notifies all
- * layers about state change by calling cl_lock_operations::clo_state()
- * top-to-bottom.
- */
-void cl_lock_signal(const struct lu_env *env, struct cl_lock *lock)
+const char *cl_lock_mode_name(const enum cl_lock_mode mode)
{
- ENTRY;
- cl_lock_state_signal(env, lock, lock->cll_state);
- EXIT;
+ static const char * const names[] = {
+ [CLM_READ] = "R",
+ [CLM_WRITE] = "W",
+ [CLM_GROUP] = "G"
+ };
+ CLASSERT(CLM_MAX == ARRAY_SIZE(names));
+ return names[mode];
}
-EXPORT_SYMBOL(cl_lock_signal);
+EXPORT_SYMBOL(cl_lock_mode_name);
/**
- * Changes lock state.
- *
- * This function is invoked to notify layers that lock state changed, possible
- * as a result of an asynchronous event such as call-back reception.
- *
- * \post lock->cll_state == state
- *
- * \see cl_lock_operations::clo_state()
+ * Prints human readable representation of a lock description.
*/
-void cl_lock_state_set(const struct lu_env *env, struct cl_lock *lock,
- enum cl_lock_state state)
-{
- struct cl_site *site = cl_object_site(lock->cll_descr.cld_obj);
-
- ENTRY;
- LASSERT(lock->cll_state <= state ||
- (lock->cll_state == CLS_CACHED &&
- (state == CLS_HELD || /* lock found in cache */
- state == CLS_NEW || /* sub-lock canceled */
- state == CLS_INTRANSIT)) ||
- /* lock is in transit state */
- lock->cll_state == CLS_INTRANSIT);
-
- if (lock->cll_state != state) {
- atomic_dec(&site->cs_locks_state[lock->cll_state]);
- atomic_inc(&site->cs_locks_state[state]);
-
- cl_lock_state_signal(env, lock, state);
- lock->cll_state = state;
- }
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_state_set);
-
-static int cl_unuse_try_internal(const struct lu_env *env, struct cl_lock *lock)
+void cl_lock_descr_print(const struct lu_env *env, void *cookie,
+ lu_printer_t printer,
+ const struct cl_lock_descr *descr)
{
- const struct cl_lock_slice *slice;
- int result;
+ const struct lu_fid *fid;
- do {
- result = 0;
-
- if (lock->cll_error != 0)
- break;
-
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_state == CLS_INTRANSIT);
- LASSERT(lock->cll_users > 0);
- LASSERT(lock->cll_holds > 0);
-
- result = -ENOSYS;
- list_for_each_entry_reverse(slice, &lock->cll_layers,
- cls_linkage) {
- if (slice->cls_ops->clo_unuse != NULL) {
- result = slice->cls_ops->clo_unuse(env, slice);
- if (result != 0)
- break;
- }
- }
- LASSERT(result != -ENOSYS);
- } while (result == CLO_REPEAT);
-
- return result ?: lock->cll_error;
+ fid = lu_object_fid(&descr->cld_obj->co_lu);
+ (*printer)(env, cookie, DDESCR"@"DFID, PDESCR(descr), PFID(fid));
}
+EXPORT_SYMBOL(cl_lock_descr_print);
/**
- * Yanks lock from the cache (cl_lock_state::CLS_CACHED state) by calling
- * cl_lock_operations::clo_use() top-to-bottom to notify layers.
- * @atomic = 1, it must unuse the lock to recovery the lock to keep the
- * use process atomic
+ * Prints human readable representation of \a lock to the \a f.
*/
-int cl_use_try(const struct lu_env *env, struct cl_lock *lock, int atomic)
+void cl_lock_print(const struct lu_env *env, void *cookie,
+ lu_printer_t printer, const struct cl_lock *lock)
{
- const struct cl_lock_slice *slice;
- int result;
- enum cl_lock_state state;
-
- ENTRY;
- result = -ENOSYS;
+ const struct cl_lock_slice *slice;
- state = cl_lock_intransit(env, lock);
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_use != NULL) {
- result = slice->cls_ops->clo_use(env, slice);
- if (result != 0)
- break;
- }
- }
- LASSERT(result != -ENOSYS);
+ (*printer)(env, cookie, "lock@%p", lock);
+ cl_lock_descr_print(env, cookie, printer, &lock->cll_descr);
+ (*printer)(env, cookie, " {\n");
- LASSERT(lock->cll_state == CLS_INTRANSIT);
-
- if (result == 0) {
- state = CLS_HELD;
- } else {
- if (result == -ESTALE) {
- /*
- * ESTALE means sublock being cancelled
- * at this time, and set lock state to
- * be NEW here and ask the caller to repeat.
- */
- state = CLS_NEW;
- result = CLO_REPEAT;
- }
-
- /* @atomic means back-off-on-failure. */
- if (atomic) {
- int rc;
-
- do {
- rc = cl_unuse_try_internal(env, lock);
- if (rc == 0)
- break;
- if (rc == CLO_WAIT)
- rc = cl_lock_state_wait(env, lock);
- if (rc < 0)
- break;
- } while(1);
-
- /* Vet the results. */
- if (rc < 0 && result > 0)
- result = rc;
- }
-
- }
- cl_lock_extransit(env, lock, state);
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_use_try);
-
-/**
- * Helper for cl_enqueue_try() that calls ->clo_enqueue() across all layers
- * top-to-bottom.
- */
-static int cl_enqueue_kick(const struct lu_env *env,
- struct cl_lock *lock,
- struct cl_io *io, __u32 flags)
-{
- int result;
- const struct cl_lock_slice *slice;
-
- ENTRY;
- result = -ENOSYS;
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_enqueue != NULL) {
- result = slice->cls_ops->clo_enqueue(env,
- slice, io, flags);
- if (result != 0)
- break;
- }
- }
- LASSERT(result != -ENOSYS);
- RETURN(result);
-}
-
-/**
- * Tries to enqueue a lock.
- *
- * This function is called repeatedly by cl_enqueue() until either lock is
- * enqueued, or error occurs. This function does not block waiting for
- * networking communication to complete.
- *
- * \post ergo(result == 0, lock->cll_state == CLS_ENQUEUED ||
- * lock->cll_state == CLS_HELD)
- *
- * \see cl_enqueue() cl_lock_operations::clo_enqueue()
- * \see cl_lock_state::CLS_ENQUEUED
- */
-int cl_enqueue_try(const struct lu_env *env, struct cl_lock *lock,
- struct cl_io *io, __u32 flags)
-{
- int result;
-
- ENTRY;
- do {
- result = 0;
-
- LINVRNT(cl_lock_is_mutexed(lock));
-
- if (lock->cll_error != 0)
- break;
- switch (lock->cll_state) {
- case CLS_NEW:
- cl_lock_state_set(env, lock, CLS_QUEUING);
- /* fall-through */
- case CLS_QUEUING:
- /* kick layers. */
- result = cl_enqueue_kick(env, lock, io, flags);
- if (result == 0)
- cl_lock_state_set(env, lock, CLS_ENQUEUED);
- break;
- case CLS_INTRANSIT:
- LASSERT(cl_lock_is_intransit(lock));
- result = CLO_WAIT;
- break;
- case CLS_CACHED:
- /* yank lock from the cache. */
- result = cl_use_try(env, lock, 0);
- break;
- case CLS_ENQUEUED:
- case CLS_HELD:
- result = 0;
- break;
- default:
- case CLS_FREEING:
- /*
- * impossible, only held locks with increased
- * ->cll_holds can be enqueued, and they cannot be
- * freed.
- */
- LBUG();
- }
- } while (result == CLO_REPEAT);
- if (result < 0)
- cl_lock_error(env, lock, result);
- RETURN(result ?: lock->cll_error);
-}
-EXPORT_SYMBOL(cl_enqueue_try);
-
-static int cl_enqueue_locked(const struct lu_env *env, struct cl_lock *lock,
- struct cl_io *io, __u32 enqflags)
-{
- int result;
-
- ENTRY;
-
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_holds > 0);
-
- cl_lock_user_add(env, lock);
- do {
- result = cl_enqueue_try(env, lock, io, enqflags);
- if (result == CLO_WAIT) {
- result = cl_lock_state_wait(env, lock);
- if (result == 0)
- continue;
- }
- break;
- } while (1);
- if (result != 0) {
- cl_lock_user_del(env, lock);
- if (result != -EINTR)
- cl_lock_error(env, lock, result);
- }
- LASSERT(ergo(result == 0, lock->cll_state == CLS_ENQUEUED ||
- lock->cll_state == CLS_HELD));
- RETURN(result);
-}
-
-/**
- * Enqueues a lock.
- *
- * \pre current thread or io owns a hold on lock.
- *
- * \post ergo(result == 0, lock->users increased)
- * \post ergo(result == 0, lock->cll_state == CLS_ENQUEUED ||
- * lock->cll_state == CLS_HELD)
- */
-int cl_enqueue(const struct lu_env *env, struct cl_lock *lock,
- struct cl_io *io, __u32 enqflags)
-{
- int result;
-
- ENTRY;
-
- cl_lock_lockdep_acquire(env, lock, enqflags);
- cl_lock_mutex_get(env, lock);
- result = cl_enqueue_locked(env, lock, io, enqflags);
- cl_lock_mutex_put(env, lock);
- if (result != 0)
- cl_lock_lockdep_release(env, lock);
- LASSERT(ergo(result == 0, lock->cll_state == CLS_ENQUEUED ||
- lock->cll_state == CLS_HELD));
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_enqueue);
-
-/**
- * Tries to unlock a lock.
- *
- * This function is called repeatedly by cl_unuse() until either lock is
- * unlocked, or error occurs.
- *
- * \pre lock->cll_state <= CLS_HELD || cl_lock_is_intransit(lock)
- *
- * \post ergo(result == 0, lock->cll_state == CLS_CACHED)
- *
- * \see cl_unuse() cl_lock_operations::clo_unuse()
- * \see cl_lock_state::CLS_CACHED
- */
-int cl_unuse_try(const struct lu_env *env, struct cl_lock *lock)
-{
- int result;
- enum cl_lock_state state = CLS_NEW;
-
- ENTRY;
- if (lock->cll_state != CLS_INTRANSIT) {
- if (lock->cll_users > 1) {
- cl_lock_user_del(env, lock);
- RETURN(0);
- }
- /*
- * New lock users (->cll_users) are not protecting unlocking
- * from proceeding. From this point, lock eventually reaches
- * CLS_CACHED, is reinitialized to CLS_NEW or fails into
- * CLS_FREEING.
- */
- state = cl_lock_intransit(env, lock);
- }
-
- result = cl_unuse_try_internal(env, lock);
- LASSERT(lock->cll_state == CLS_INTRANSIT);
- if (result != CLO_WAIT)
- /*
- * Once there is no more need to iterate ->clo_unuse() calls,
- * remove lock user. This is done even if unrecoverable error
- * happened during unlocking, because nothing else can be
- * done.
- */
- cl_lock_user_del(env, lock);
- if (result == 0 || result == -ESTALE) {
- /*
- * Return lock back to the cache. This is the only
- * place where lock is moved into CLS_CACHED state.
- *
- * If one of ->clo_unuse() methods returned -ESTALE, lock
- * cannot be placed into cache and has to be
- * re-initialized. This happens e.g., when a sub-lock was
- * canceled while unlocking was in progress.
- */
- state = result == 0 ? CLS_CACHED : CLS_NEW;
- cl_lock_extransit(env, lock, state);
-
- /*
- * Hide -ESTALE error.
- * If the lock is a glimpse lock, and it has multiple
- * stripes. Assuming that one of its sublock returned -ENAVAIL,
- * and other sublocks are matched write locks. In this case,
- * we can't set this lock to error because otherwise some of
- * its sublocks may not be canceled. This causes some dirty
- * pages won't be written to OSTs. -jay
- */
- result = 0;
- } else {
- CWARN("result = %d, this is unlikely!\n", result);
- cl_lock_extransit(env, lock, state);
- }
-
- result = result ?: lock->cll_error;
- if (result < 0)
- cl_lock_error(env, lock, result);
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_unuse_try);
-
-static void cl_unuse_locked(const struct lu_env *env, struct cl_lock *lock)
-{
- ENTRY;
- LASSERT(lock->cll_state <= CLS_HELD);
- do {
- int result;
-
- result = cl_unuse_try(env, lock);
- if (result == CLO_WAIT) {
- result = cl_lock_state_wait(env, lock);
- if (result == 0)
- continue;
- }
- break;
- } while (1);
- EXIT;
-}
-
-/**
- * Unlocks a lock.
- */
-void cl_unuse(const struct lu_env *env, struct cl_lock *lock)
-{
- ENTRY;
- cl_lock_mutex_get(env, lock);
- cl_unuse_locked(env, lock);
- cl_lock_mutex_put(env, lock);
- cl_lock_lockdep_release(env, lock);
- EXIT;
-}
-EXPORT_SYMBOL(cl_unuse);
-
-/**
- * Tries to wait for a lock.
- *
- * This function is called repeatedly by cl_wait() until either lock is
- * granted, or error occurs. This function does not block waiting for network
- * communication to complete.
- *
- * \see cl_wait() cl_lock_operations::clo_wait()
- * \see cl_lock_state::CLS_HELD
- */
-int cl_wait_try(const struct lu_env *env, struct cl_lock *lock)
-{
- const struct cl_lock_slice *slice;
- int result;
-
- ENTRY;
- do {
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_state == CLS_ENQUEUED ||
- lock->cll_state == CLS_HELD ||
- lock->cll_state == CLS_INTRANSIT);
- LASSERT(lock->cll_users > 0);
- LASSERT(lock->cll_holds > 0);
-
- result = 0;
- if (lock->cll_error != 0)
- break;
-
- if (cl_lock_is_intransit(lock)) {
- result = CLO_WAIT;
- break;
- }
-
- if (lock->cll_state == CLS_HELD)
- /* nothing to do */
- break;
-
- result = -ENOSYS;
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_wait != NULL) {
- result = slice->cls_ops->clo_wait(env, slice);
- if (result != 0)
- break;
- }
- }
- LASSERT(result != -ENOSYS);
- if (result == 0)
- cl_lock_state_set(env, lock, CLS_HELD);
- } while (result == CLO_REPEAT);
- RETURN(result ?: lock->cll_error);
-}
-EXPORT_SYMBOL(cl_wait_try);
-
-/**
- * Waits until enqueued lock is granted.
- *
- * \pre current thread or io owns a hold on the lock
- * \pre ergo(result == 0, lock->cll_state == CLS_ENQUEUED ||
- * lock->cll_state == CLS_HELD)
- *
- * \post ergo(result == 0, lock->cll_state == CLS_HELD)
- */
-int cl_wait(const struct lu_env *env, struct cl_lock *lock)
-{
- int result;
-
- ENTRY;
- cl_lock_mutex_get(env, lock);
-
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_state == CLS_ENQUEUED || lock->cll_state == CLS_HELD);
- LASSERT(lock->cll_holds > 0);
-
- do {
- result = cl_wait_try(env, lock);
- if (result == CLO_WAIT) {
- result = cl_lock_state_wait(env, lock);
- if (result == 0)
- continue;
- }
- break;
- } while (1);
- if (result < 0) {
- cl_lock_user_del(env, lock);
- if (result != -EINTR)
- cl_lock_error(env, lock, result);
- cl_lock_lockdep_release(env, lock);
- }
- cl_lock_mutex_put(env, lock);
- LASSERT(ergo(result == 0, lock->cll_state == CLS_HELD));
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_wait);
-
-/**
- * Executes cl_lock_operations::clo_weigh(), and sums results to estimate lock
- * value.
- */
-unsigned long cl_lock_weigh(const struct lu_env *env, struct cl_lock *lock)
-{
- const struct cl_lock_slice *slice;
- unsigned long pound;
- unsigned long ounce;
-
- ENTRY;
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- pound = 0;
- list_for_each_entry_reverse(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_weigh != NULL) {
- ounce = slice->cls_ops->clo_weigh(env, slice);
- pound += ounce;
- if (pound < ounce) /* over-weight^Wflow */
- pound = ~0UL;
- }
- }
- RETURN(pound);
-}
-EXPORT_SYMBOL(cl_lock_weigh);
-
-/**
- * Notifies layers that lock description changed.
- *
- * The server can grant client a lock different from one that was requested
- * (e.g., larger in extent). This method is called when actually granted lock
- * description becomes known to let layers to accommodate for changed lock
- * description.
- *
- * \see cl_lock_operations::clo_modify()
- */
-int cl_lock_modify(const struct lu_env *env, struct cl_lock *lock,
- const struct cl_lock_descr *desc)
-{
- const struct cl_lock_slice *slice;
- struct cl_object *obj = lock->cll_descr.cld_obj;
- struct cl_object_header *hdr = cl_object_header(obj);
- int result;
-
- ENTRY;
- /* don't allow object to change */
- LASSERT(obj == desc->cld_obj);
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- list_for_each_entry_reverse(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_modify != NULL) {
- result = slice->cls_ops->clo_modify(env, slice, desc);
- if (result != 0)
- RETURN(result);
- }
- }
- CL_LOCK_DEBUG(D_DLMTRACE, env, lock, " -> "DDESCR"@"DFID"\n",
- PDESCR(desc), PFID(lu_object_fid(&desc->cld_obj->co_lu)));
- /*
- * Just replace description in place. Nothing more is needed for
- * now. If locks were indexed according to their extent and/or mode,
- * that index would have to be updated here.
- */
- spin_lock(&hdr->coh_lock_guard);
- lock->cll_descr = *desc;
- spin_unlock(&hdr->coh_lock_guard);
- RETURN(0);
-}
-EXPORT_SYMBOL(cl_lock_modify);
-
-/**
- * Initializes lock closure with a given origin.
- *
- * \see cl_lock_closure
- */
-void cl_lock_closure_init(const struct lu_env *env,
- struct cl_lock_closure *closure,
- struct cl_lock *origin, int wait)
-{
- LINVRNT(cl_lock_is_mutexed(origin));
- LINVRNT(cl_lock_invariant(env, origin));
-
- CFS_INIT_LIST_HEAD(&closure->clc_list);
- closure->clc_origin = origin;
- closure->clc_wait = wait;
- closure->clc_nr = 0;
-}
-EXPORT_SYMBOL(cl_lock_closure_init);
-
-/**
- * Builds a closure of \a lock.
- *
- * Building of a closure consists of adding initial lock (\a lock) into it,
- * and calling cl_lock_operations::clo_closure() methods of \a lock. These
- * methods might call cl_lock_closure_build() recursively again, adding more
- * locks to the closure, etc.
- *
- * \see cl_lock_closure
- */
-int cl_lock_closure_build(const struct lu_env *env, struct cl_lock *lock,
- struct cl_lock_closure *closure)
-{
- const struct cl_lock_slice *slice;
- int result;
-
- ENTRY;
- LINVRNT(cl_lock_is_mutexed(closure->clc_origin));
- LINVRNT(cl_lock_invariant(env, closure->clc_origin));
-
- result = cl_lock_enclosure(env, lock, closure);
- if (result == 0) {
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- if (slice->cls_ops->clo_closure != NULL) {
- result = slice->cls_ops->clo_closure(env, slice,
- closure);
- if (result != 0)
- break;
- }
- }
- }
- if (result != 0)
- cl_lock_disclosure(env, closure);
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_lock_closure_build);
-
-/**
- * Adds new lock to a closure.
- *
- * Try-locks \a lock and if succeeded, adds it to the closure (never more than
- * once). If try-lock failed, returns CLO_REPEAT, after optionally waiting
- * until next try-lock is likely to succeed.
- */
-int cl_lock_enclosure(const struct lu_env *env, struct cl_lock *lock,
- struct cl_lock_closure *closure)
-{
- int result;
- ENTRY;
- if (!cl_lock_mutex_try(env, lock)) {
- /*
- * If lock->cll_inclosure is not empty, lock is already in
- * this closure.
- */
- if (list_empty(&lock->cll_inclosure)) {
- cl_lock_get_trust(lock);
- lu_ref_add(&lock->cll_reference, "closure", closure);
- list_add(&lock->cll_inclosure, &closure->clc_list);
- closure->clc_nr++;
- } else
- cl_lock_mutex_put(env, lock);
- result = 0;
- } else {
- cl_lock_disclosure(env, closure);
- if (closure->clc_wait) {
- cl_lock_get_trust(lock);
- lu_ref_add(&lock->cll_reference, "closure-w", closure);
- cl_lock_mutex_put(env, closure->clc_origin);
-
- LASSERT(cl_lock_nr_mutexed(env) == 0);
- cl_lock_mutex_get(env, lock);
- cl_lock_mutex_put(env, lock);
-
- cl_lock_mutex_get(env, closure->clc_origin);
- lu_ref_del(&lock->cll_reference, "closure-w", closure);
- cl_lock_put(env, lock);
- }
- result = CLO_REPEAT;
- }
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_lock_enclosure);
-
-/** Releases mutices of enclosed locks. */
-void cl_lock_disclosure(const struct lu_env *env,
- struct cl_lock_closure *closure)
-{
- struct cl_lock *scan;
- struct cl_lock *temp;
-
- list_for_each_entry_safe(scan, temp, &closure->clc_list, cll_inclosure){
- list_del_init(&scan->cll_inclosure);
- cl_lock_mutex_put(env, scan);
- lu_ref_del(&scan->cll_reference, "closure", closure);
- cl_lock_put(env, scan);
- closure->clc_nr--;
- }
- LASSERT(closure->clc_nr == 0);
-}
-EXPORT_SYMBOL(cl_lock_disclosure);
-
-/** Finalizes a closure. */
-void cl_lock_closure_fini(struct cl_lock_closure *closure)
-{
- LASSERT(closure->clc_nr == 0);
- LASSERT(list_empty(&closure->clc_list));
-}
-EXPORT_SYMBOL(cl_lock_closure_fini);
-
-/**
- * Destroys this lock. Notifies layers (bottom-to-top) that lock is being
- * destroyed, then destroy the lock. If there are holds on the lock, postpone
- * destruction until all holds are released. This is called when a decision is
- * made to destroy the lock in the future. E.g., when a blocking AST is
- * received on it, or fatal communication error happens.
- *
- * Caller must have a reference on this lock to prevent a situation, when
- * deleted lock lingers in memory for indefinite time, because nobody calls
- * cl_lock_put() to finish it.
- *
- * \pre atomic_read(&lock->cll_ref) > 0
- * \pre ergo(cl_lock_nesting(lock) == CNL_TOP,
- * cl_lock_nr_mutexed(env) == 1)
- * [i.e., if a top-lock is deleted, mutices of no other locks can be
- * held, as deletion of sub-locks might require releasing a top-lock
- * mutex]
- *
- * \see cl_lock_operations::clo_delete()
- * \see cl_lock::cll_holds
- */
-void cl_lock_delete(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(ergo(cl_lock_nesting(lock) == CNL_TOP,
- cl_lock_nr_mutexed(env) == 1));
-
- ENTRY;
- if (lock->cll_holds == 0)
- cl_lock_delete0(env, lock);
- else
- lock->cll_flags |= CLF_DOOMED;
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_delete);
-
-/**
- * Mark lock as irrecoverably failed, and mark it for destruction. This
- * happens when, e.g., server fails to grant a lock to us, or networking
- * time-out happens.
- *
- * \pre atomic_read(&lock->cll_ref) > 0
- *
- * \see clo_lock_delete()
- * \see cl_lock::cll_holds
- */
-void cl_lock_error(const struct lu_env *env, struct cl_lock *lock, int error)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- ENTRY;
- if (lock->cll_error == 0 && error != 0) {
- lock->cll_error = error;
- cl_lock_signal(env, lock);
- cl_lock_cancel(env, lock);
- cl_lock_delete(env, lock);
- }
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_error);
-
-/**
- * Cancels this lock. Notifies layers
- * (bottom-to-top) that lock is being cancelled, then destroy the lock. If
- * there are holds on the lock, postpone cancellation until
- * all holds are released.
- *
- * Cancellation notification is delivered to layers at most once.
- *
- * \see cl_lock_operations::clo_cancel()
- * \see cl_lock::cll_holds
- */
-void cl_lock_cancel(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- ENTRY;
- if (lock->cll_holds == 0)
- cl_lock_cancel0(env, lock);
- else
- lock->cll_flags |= CLF_CANCELPEND;
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_cancel);
-
-/**
- * Finds an existing lock covering given page and optionally different from a
- * given \a except lock.
- */
-struct cl_lock *cl_lock_at_page(const struct lu_env *env, struct cl_object *obj,
- struct cl_page *page, struct cl_lock *except,
- int pending, int canceld)
-{
- struct cl_object_header *head;
- struct cl_lock *scan;
- struct cl_lock *lock;
- struct cl_lock_descr *need;
-
- ENTRY;
-
- head = cl_object_header(obj);
- need = &cl_env_info(env)->clt_descr;
- lock = NULL;
-
- need->cld_mode = CLM_READ; /* CLM_READ matches both READ & WRITE, but
- * not PHANTOM */
- need->cld_start = need->cld_end = page->cp_index;
-
- spin_lock(&head->coh_lock_guard);
- list_for_each_entry(scan, &head->coh_locks, cll_linkage) {
- if (scan != except &&
- cl_lock_ext_match(&scan->cll_descr, need) &&
- scan->cll_state >= CLS_HELD &&
- scan->cll_state < CLS_FREEING &&
- /*
- * This check is racy as the lock can be canceled right
- * after it is done, but this is fine, because page exists
- * already.
- */
- (canceld || !(scan->cll_flags & CLF_CANCELLED)) &&
- (pending || !(scan->cll_flags & CLF_CANCELPEND))) {
- /* Don't increase cs_hit here since this
- * is just a helper function. */
- cl_lock_get_trust(scan);
- lock = scan;
- break;
- }
- }
- spin_unlock(&head->coh_lock_guard);
- RETURN(lock);
-}
-EXPORT_SYMBOL(cl_lock_at_page);
-
-/**
- * Returns a list of pages protected (only) by a given lock.
- *
- * Scans an extent of page radix tree, corresponding to the \a lock and queues
- * all pages that are not protected by locks other than \a lock into \a queue.
- */
-void cl_lock_page_list_fixup(const struct lu_env *env,
- struct cl_io *io, struct cl_lock *lock,
- struct cl_page_list *queue)
-{
- struct cl_page *page;
- struct cl_page *temp;
- struct cl_page_list *plist = &cl_env_info(env)->clt_list;
-
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
-
- /* Now, we have a list of cl_pages under the \a lock, we need
- * to check if some of pages are covered by other ldlm lock.
- * If this is the case, they aren't needed to be written out this time.
- *
- * For example, we have A:[0,200] & B:[100,300] PW locks on client, now
- * the latter is to be canceled, this means other client is
- * reading/writing [200,300] since A won't canceled. Actually
- * we just need to write the pages covered by [200,300]. This is safe,
- * since [100,200] is also protected lock A.
- */
-
- cl_page_list_init(plist);
- cl_page_list_for_each_safe(page, temp, queue) {
- pgoff_t idx = page->cp_index;
- struct cl_lock *found;
- struct cl_lock_descr *descr;
-
- /* The algorithm counts on the index-ascending page index. */
- LASSERT(ergo(&temp->cp_batch != &queue->pl_pages,
- page->cp_index < temp->cp_index));
-
- found = cl_lock_at_page(env, lock->cll_descr.cld_obj,
- page, lock, 0, 0);
- if (found == NULL)
- continue;
-
- descr = &found->cll_descr;
- list_for_each_entry_safe_from(page, temp, &queue->pl_pages,
- cp_batch) {
- idx = page->cp_index;
- if (descr->cld_start > idx || descr->cld_end < idx)
- break;
- cl_page_list_move(plist, queue, page);
- }
- cl_lock_put(env, found);
- }
-
- /* The pages in plist are covered by other locks, don't handle them
- * this time.
- */
- if (io != NULL)
- cl_page_list_disown(env, io, plist);
- cl_page_list_fini(env, plist);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_page_list_fixup);
-
-/**
- * Invalidate pages protected by the given lock, sending them out to the
- * server first, if necessary.
- *
- * This function does the following:
- *
- * - collects a list of pages to be invalidated,
- *
- * - unmaps them from the user virtual memory,
- *
- * - sends dirty pages to the server,
- *
- * - waits for transfer completion,
- *
- * - discards pages, and throws them out of memory.
- *
- * If \a discard is set, pages are discarded without sending them to the
- * server.
- *
- * If error happens on any step, the process continues anyway (the reasoning
- * behind this being that lock cancellation cannot be delayed indefinitely).
- */
-int cl_lock_page_out(const struct lu_env *env, struct cl_lock *lock,
- int discard)
-{
- struct cl_thread_info *info = cl_env_info(env);
- struct cl_io *io = &info->clt_io;
- struct cl_2queue *queue = &info->clt_queue;
- struct cl_lock_descr *descr = &lock->cll_descr;
- long page_count;
- int result;
-
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
-
- io->ci_obj = cl_object_top(descr->cld_obj);
- result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
- if (result == 0) {
- int nonblock = 1;
-
-restart:
- cl_2queue_init(queue);
- cl_page_gang_lookup(env, descr->cld_obj, io, descr->cld_start,
- descr->cld_end, &queue->c2_qin, nonblock);
- page_count = queue->c2_qin.pl_nr;
- if (page_count > 0) {
- result = cl_page_list_unmap(env, io, &queue->c2_qin);
- if (!discard) {
- long timeout = 600; /* 10 minutes. */
- /* for debug purpose, if this request can't be
- * finished in 10 minutes, we hope it can
- * notify us.
- */
- result = cl_io_submit_sync(env, io, CRT_WRITE,
- queue, CRP_CANCEL,
- timeout);
- if (result)
- CWARN("Writing %lu pages error: %d\n",
- page_count, result);
- }
- cl_lock_page_list_fixup(env, io, lock, &queue->c2_qout);
- cl_2queue_discard(env, io, queue);
- cl_2queue_disown(env, io, queue);
- }
- cl_2queue_fini(env, queue);
-
- if (nonblock) {
- nonblock = 0;
- goto restart;
- }
- }
- cl_io_fini(env, io);
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_lock_page_out);
-
-/**
- * Eliminate all locks for a given object.
- *
- * Caller has to guarantee that no lock is in active use.
- *
- * \param cancel when this is set, cl_locks_prune() cancels locks before
- * destroying.
- */
-void cl_locks_prune(const struct lu_env *env, struct cl_object *obj, int cancel)
-{
- struct cl_object_header *head;
- struct cl_lock *lock;
-
- ENTRY;
- head = cl_object_header(obj);
- /*
- * If locks are destroyed without cancellation, all pages must be
- * already destroyed (as otherwise they will be left unprotected).
- */
- LASSERT(ergo(!cancel,
- head->coh_tree.rnode == NULL && head->coh_pages == 0));
-
- spin_lock(&head->coh_lock_guard);
- while (!list_empty(&head->coh_locks)) {
- lock = container_of(head->coh_locks.next,
- struct cl_lock, cll_linkage);
- cl_lock_get_trust(lock);
- spin_unlock(&head->coh_lock_guard);
- lu_ref_add(&lock->cll_reference, "prune", cfs_current());
- cl_lock_mutex_get(env, lock);
- if (lock->cll_state < CLS_FREEING) {
- LASSERT(lock->cll_holds == 0);
- LASSERT(lock->cll_users == 0);
- if (cancel)
- cl_lock_cancel(env, lock);
- cl_lock_delete(env, lock);
- }
- cl_lock_mutex_put(env, lock);
- lu_ref_del(&lock->cll_reference, "prune", cfs_current());
- cl_lock_put(env, lock);
- spin_lock(&head->coh_lock_guard);
- }
- spin_unlock(&head->coh_lock_guard);
- EXIT;
-}
-EXPORT_SYMBOL(cl_locks_prune);
-
-/**
- * Returns true if \a addr is an address of an allocated cl_lock. Used in
- * assertions. This check is optimistically imprecise, i.e., it occasionally
- * returns true for the incorrect addresses, but if it returns false, then the
- * address is guaranteed to be incorrect. (Should be named cl_lockp().)
- *
- * \see cl_is_page()
- */
-int cl_is_lock(const void *addr)
-{
- return cfs_mem_is_in_cache(addr, cl_lock_kmem);
-}
-EXPORT_SYMBOL(cl_is_lock);
-
-static struct cl_lock *cl_lock_hold_mutex(const struct lu_env *env,
- const struct cl_io *io,
- const struct cl_lock_descr *need,
- const char *scope, const void *source)
-{
- struct cl_lock *lock;
-
- ENTRY;
-
- while (1) {
- lock = cl_lock_find(env, io, need);
- if (IS_ERR(lock))
- break;
- cl_lock_mutex_get(env, lock);
- if (lock->cll_state < CLS_FREEING) {
- cl_lock_hold_mod(env, lock, +1);
- lu_ref_add(&lock->cll_holders, scope, source);
- lu_ref_add(&lock->cll_reference, scope, source);
- break;
- }
- cl_lock_mutex_put(env, lock);
- cl_lock_put(env, lock);
- }
- RETURN(lock);
-}
-
-/**
- * Returns a lock matching \a need description with a reference and a hold on
- * it.
- *
- * This is much like cl_lock_find(), except that cl_lock_hold() additionally
- * guarantees that lock is not in the CLS_FREEING state on return.
- */
-struct cl_lock *cl_lock_hold(const struct lu_env *env, const struct cl_io *io,
- const struct cl_lock_descr *need,
- const char *scope, const void *source)
-{
- struct cl_lock *lock;
-
- ENTRY;
-
- lock = cl_lock_hold_mutex(env, io, need, scope, source);
- if (!IS_ERR(lock))
- cl_lock_mutex_put(env, lock);
- RETURN(lock);
-}
-EXPORT_SYMBOL(cl_lock_hold);
-
-/**
- * Main high-level entry point of cl_lock interface that finds existing or
- * enqueues new lock matching given description.
- */
-struct cl_lock *cl_lock_request(const struct lu_env *env, struct cl_io *io,
- const struct cl_lock_descr *need,
- __u32 enqflags,
- const char *scope, const void *source)
-{
- struct cl_lock *lock;
- const struct lu_fid *fid;
- int rc;
- int iter;
- int warn;
-
- ENTRY;
- fid = lu_object_fid(&io->ci_obj->co_lu);
- iter = 0;
- do {
- warn = iter >= 16 && IS_PO2(iter);
- CDEBUG(warn ? D_WARNING : D_DLMTRACE,
- DDESCR"@"DFID" %i %08x `%s'\n",
- PDESCR(need), PFID(fid), iter, enqflags, scope);
- lock = cl_lock_hold_mutex(env, io, need, scope, source);
- if (!IS_ERR(lock)) {
- rc = cl_enqueue_locked(env, lock, io, enqflags);
- if (rc == 0) {
- if (cl_lock_fits_into(env, lock, need, io)) {
- cl_lock_mutex_put(env, lock);
- cl_lock_lockdep_acquire(env,
- lock, enqflags);
- break;
- } else if (warn)
- CL_LOCK_DEBUG(D_WARNING, env, lock,
- "got (see bug 17665)\n");
- cl_unuse_locked(env, lock);
- }
- cl_lock_hold_release(env, lock, scope, source);
- cl_lock_mutex_put(env, lock);
- lu_ref_del(&lock->cll_reference, scope, source);
- cl_lock_put(env, lock);
- lock = ERR_PTR(rc);
- } else
- rc = PTR_ERR(lock);
- iter++;
- } while (rc == 0);
- RETURN(lock);
-}
-EXPORT_SYMBOL(cl_lock_request);
-
-/**
- * Adds a hold to a known lock.
- */
-void cl_lock_hold_add(const struct lu_env *env, struct cl_lock *lock,
- const char *scope, const void *source)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_state != CLS_FREEING);
-
- ENTRY;
- cl_lock_hold_mod(env, lock, +1);
- cl_lock_get(lock);
- lu_ref_add(&lock->cll_holders, scope, source);
- lu_ref_add(&lock->cll_reference, scope, source);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_hold_add);
-
-/**
- * Releases a hold and a reference on a lock, on which caller acquired a
- * mutex.
- */
-void cl_lock_unhold(const struct lu_env *env, struct cl_lock *lock,
- const char *scope, const void *source)
-{
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
- cl_lock_hold_release(env, lock, scope, source);
- lu_ref_del(&lock->cll_reference, scope, source);
- cl_lock_put(env, lock);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_unhold);
-
-/**
- * Releases a hold and a reference on a lock, obtained by cl_lock_hold().
- */
-void cl_lock_release(const struct lu_env *env, struct cl_lock *lock,
- const char *scope, const void *source)
-{
- LINVRNT(cl_lock_invariant(env, lock));
- ENTRY;
- cl_lock_mutex_get(env, lock);
- cl_lock_hold_release(env, lock, scope, source);
- cl_lock_mutex_put(env, lock);
- lu_ref_del(&lock->cll_reference, scope, source);
- cl_lock_put(env, lock);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_release);
-
-void cl_lock_user_add(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
-
- ENTRY;
- cl_lock_used_mod(env, lock, +1);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_user_add);
-
-int cl_lock_user_del(const struct lu_env *env, struct cl_lock *lock)
-{
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_users > 0);
-
- ENTRY;
- cl_lock_used_mod(env, lock, -1);
- RETURN(lock->cll_users == 0);
-}
-EXPORT_SYMBOL(cl_lock_user_del);
-
-/**
- * Check if two lock's mode are compatible.
- *
- * This returns true iff en-queuing \a lock2 won't cause cancellation of \a
- * lock1 even when these locks overlap.
- */
-int cl_lock_compatible(const struct cl_lock *lock1, const struct cl_lock *lock2)
-{
- enum cl_lock_mode mode1;
- enum cl_lock_mode mode2;
-
- ENTRY;
- mode1 = lock1->cll_descr.cld_mode;
- mode2 = lock2->cll_descr.cld_mode;
- RETURN(mode2 == CLM_PHANTOM ||
- (mode1 == CLM_READ && mode2 == CLM_READ));
-}
-EXPORT_SYMBOL(cl_lock_compatible);
-
-const char *cl_lock_mode_name(const enum cl_lock_mode mode)
-{
- static const char *names[] = {
- [CLM_PHANTOM] = "PHANTOM",
- [CLM_READ] = "READ",
- [CLM_WRITE] = "WRITE",
- [CLM_GROUP] = "GROUP"
- };
- if (0 <= mode && mode < ARRAY_SIZE(names))
- return names[mode];
- else
- return "UNKNW";
-}
-EXPORT_SYMBOL(cl_lock_mode_name);
-
-/**
- * Prints human readable representation of a lock description.
- */
-void cl_lock_descr_print(const struct lu_env *env, void *cookie,
- lu_printer_t printer,
- const struct cl_lock_descr *descr)
-{
- const struct lu_fid *fid;
-
- fid = lu_object_fid(&descr->cld_obj->co_lu);
- (*printer)(env, cookie, DDESCR"@"DFID, PDESCR(descr), PFID(fid));
-}
-EXPORT_SYMBOL(cl_lock_descr_print);
-
-/**
- * Prints human readable representation of \a lock to the \a f.
- */
-void cl_lock_print(const struct lu_env *env, void *cookie,
- lu_printer_t printer, const struct cl_lock *lock)
-{
- const struct cl_lock_slice *slice;
- (*printer)(env, cookie, "lock@%p[%d %d %d %d %d %08lx] ",
- lock, atomic_read(&lock->cll_ref),
- lock->cll_state, lock->cll_error, lock->cll_holds,
- lock->cll_users, lock->cll_flags);
- cl_lock_descr_print(env, cookie, printer, &lock->cll_descr);
- (*printer)(env, cookie, " {\n");
-
- list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
- (*printer)(env, cookie, " %s@%p: ",
- slice->cls_obj->co_lu.lo_dev->ld_type->ldt_name,
- slice);
- if (slice->cls_ops->clo_print != NULL)
- slice->cls_ops->clo_print(env, cookie, printer, slice);
- (*printer)(env, cookie, "\n");
- }
- (*printer)(env, cookie, "} lock@%p\n", lock);
+ list_for_each_entry(slice, &lock->cll_layers, cls_linkage) {
+ (*printer)(env, cookie, " %s@%p: ",
+ slice->cls_obj->co_lu.lo_dev->ld_type->ldt_name,
+ slice);
+ if (slice->cls_ops->clo_print != NULL)
+ slice->cls_ops->clo_print(env, cookie, printer, slice);
+ (*printer)(env, cookie, "\n");
+ }
+ (*printer)(env, cookie, "} lock@%p\n", lock);
}
EXPORT_SYMBOL(cl_lock_print);
-
-int cl_lock_init(void)
-{
- return lu_kmem_init(cl_lock_caches);
-}
-
-void cl_lock_fini(void)
-{
- lu_kmem_fini(cl_lock_caches);
-}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff