-/**
- * 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)
-{
- ENTRY;
- cl_lock_trace(D_DLMTRACE, env, "state signal lock", lock);
- cl_lock_state_signal(env, lock, lock->cll_state);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_signal);
-
-/**
- * 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()
- */
-void cl_lock_state_set(const struct lu_env *env, struct cl_lock *lock,
- enum cl_lock_state state)
-{
- 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) {
- CS_LOCKSTATE_DEC(lock->cll_descr.cld_obj, lock->cll_state);
- CS_LOCKSTATE_INC(lock->cll_descr.cld_obj, 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)
-{
- const struct cl_lock_slice *slice;
- int result;
-
- do {
- result = 0;
-
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERT(lock->cll_state == CLS_INTRANSIT);
-
- 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;
-}
-
-/**
- * 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
- */
-int cl_use_try(const struct lu_env *env, struct cl_lock *lock, int atomic)
-{
- const struct cl_lock_slice *slice;
- int result;
- enum cl_lock_state state;
-
- ENTRY;
- cl_lock_trace(D_DLMTRACE, env, "use lock", lock);
-
- LASSERT(lock->cll_state == CLS_CACHED);
- if (lock->cll_error)
- RETURN(lock->cll_error);
-
- result = -ENOSYS;
- 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);
-
- LASSERTF(lock->cll_state == CLS_INTRANSIT, "Wrong state %d.\n",
- lock->cll_state);
-
- 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;
- rc = cl_unuse_try_internal(env, lock);
- /* 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;
- cl_lock_trace(D_DLMTRACE, env, "enqueue lock", lock);
- do {
- LINVRNT(cl_lock_is_mutexed(lock));
-
- result = lock->cll_error;
- if (result != 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);
- /* For AGL case, the cl_lock::cll_state may
- * become CLS_HELD already. */
- if (result == 0 && lock->cll_state == CLS_QUEUING)
- 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);
- RETURN(result);
-}
-EXPORT_SYMBOL(cl_enqueue_try);
-
-/**
- * Cancel the conflicting lock found during previous enqueue.
- *
- * \retval 0 conflicting lock has been canceled.
- * \retval -ve error code.
- */
-int cl_lock_enqueue_wait(const struct lu_env *env,
- struct cl_lock *lock,
- int keep_mutex)
-{
- struct cl_lock *conflict;
- int rc = 0;
- ENTRY;
-
- LASSERT(cl_lock_is_mutexed(lock));
- LASSERT(lock->cll_state == CLS_QUEUING);
- LASSERT(lock->cll_conflict != NULL);
-
- conflict = lock->cll_conflict;
- lock->cll_conflict = NULL;
-
- cl_lock_mutex_put(env, lock);
- LASSERT(cl_lock_nr_mutexed(env) == 0);
-
- cl_lock_mutex_get(env, conflict);
- cl_lock_trace(D_DLMTRACE, env, "enqueue wait", conflict);
- cl_lock_cancel(env, conflict);
- cl_lock_delete(env, conflict);
-
- while (conflict->cll_state != CLS_FREEING) {
- rc = cl_lock_state_wait(env, conflict);
- if (rc != 0)
- break;
- }
- cl_lock_mutex_put(env, conflict);
- lu_ref_del(&conflict->cll_reference, "cancel-wait", lock);
- cl_lock_put(env, conflict);
-
- if (keep_mutex)
- cl_lock_mutex_get(env, lock);
-
- LASSERT(rc <= 0);
- RETURN(rc);
-}
-EXPORT_SYMBOL(cl_lock_enqueue_wait);
-
-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) {
- if (lock->cll_conflict != NULL)
- result = cl_lock_enqueue_wait(env, lock, 1);
- else
- result = cl_lock_state_wait(env, lock);
- if (result == 0)
- continue;
- }
- break;
- } while (1);
- if (result != 0)
- cl_unuse_try(env, lock);
- LASSERT(ergo(result == 0 && !(enqflags & CEF_AGL),
- 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 to release underlying resource:
- * 1. for top lock, the resource is sublocks it held;
- * 2. for sublock, the resource is the reference to dlmlock.
- *
- * cl_unuse_try is a one-shot operation, so it must NOT return CLO_WAIT.
- *
- * \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;
- cl_lock_trace(D_DLMTRACE, env, "unuse lock", lock);
-
- if (lock->cll_users > 1) {
- cl_lock_user_del(env, lock);
- RETURN(0);
- }
-
- /* Only if the lock is in CLS_HELD or CLS_ENQUEUED state, it can hold
- * underlying resources. */
- if (!(lock->cll_state == CLS_HELD || lock->cll_state == CLS_ENQUEUED)) {
- 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);
- LASSERT(result != CLO_WAIT);
- 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.
- */
- if (state == CLS_HELD && result == 0)
- state = CLS_CACHED;
- else
- state = 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 {
- CERROR("result = %d, this is unlikely!\n", result);
- state = CLS_NEW;
- cl_lock_extransit(env, lock, state);
- }
- RETURN(result ?: lock->cll_error);
-}
-EXPORT_SYMBOL(cl_unuse_try);
-
-static void cl_unuse_locked(const struct lu_env *env, struct cl_lock *lock)
-{
- int result;
- ENTRY;
-
- result = cl_unuse_try(env, lock);
- if (result)
- CL_LOCK_DEBUG(D_ERROR, env, lock, "unuse return %d\n", result);
-
- 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;
- cl_lock_trace(D_DLMTRACE, env, "wait lock try", lock);
- do {
- LINVRNT(cl_lock_is_mutexed(lock));
- LINVRNT(cl_lock_invariant(env, lock));
- LASSERTF(lock->cll_state == CLS_QUEUING ||
- lock->cll_state == CLS_ENQUEUED ||
- lock->cll_state == CLS_HELD ||
- lock->cll_state == CLS_INTRANSIT,
- "lock state: %d\n", lock->cll_state);
- LASSERT(lock->cll_users > 0);
- LASSERT(lock->cll_holds > 0);
-
- result = lock->cll_error;
- if (result != 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) {
- LASSERT(lock->cll_state != CLS_INTRANSIT);
- cl_lock_state_set(env, lock, CLS_HELD);
- }
- } while (result == CLO_REPEAT);
- RETURN(result);
-}
-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));
- LASSERTF(lock->cll_state == CLS_ENQUEUED || lock->cll_state == CLS_HELD,
- "Wrong state %d \n", lock->cll_state);
- 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_unuse_try(env, lock);
- cl_lock_lockdep_release(env, lock);
- }
- cl_lock_trace(D_DLMTRACE, env, "wait lock", 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;
- cl_lock_trace(D_DLMTRACE, env, "modify lock", lock);
- /* 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));
-
- 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 = 0;
- ENTRY;
- cl_lock_trace(D_DLMTRACE, env, "enclosure lock", lock);
- 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;
-
- cl_lock_trace(D_DLMTRACE, env, "disclosure lock", closure->clc_origin);
- 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;
- cl_lock_trace(D_DLMTRACE, env, "delete lock", lock);
- 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) {
- cl_lock_trace(D_DLMTRACE, env, "set lock error", lock);
- 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;
- cl_lock_trace(D_DLMTRACE, env, "cancel lock", lock);
- 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 index and optionally different from a
- * given \a except lock.
- */
-struct cl_lock *cl_lock_at_pgoff(const struct lu_env *env,
- struct cl_object *obj, pgoff_t index,
- 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 = index;
- need->cld_enq_flags = 0;
-
- spin_lock(&head->coh_lock_guard);
- /* It is fine to match any group lock since there could be only one
- * with a uniq gid and it conflicts with all other lock modes too */
- list_for_each_entry(scan, &head->coh_locks, cll_linkage) {
- if (scan != except &&
- (scan->cll_descr.cld_mode == CLM_GROUP ||
- 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_pgoff);
-
-/**
- * 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);
-
- 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", current);
-
-again:
- cl_lock_mutex_get(env, lock);
- if (lock->cll_state < CLS_FREEING) {
- LASSERT(lock->cll_users <= 1);
- if (unlikely(lock->cll_users == 1)) {
- struct l_wait_info lwi = { 0 };
-
- cl_lock_mutex_put(env, lock);
- l_wait_event(lock->cll_wq,
- lock->cll_users == 0,
- &lwi);
- goto again;
- }
-
- 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", current);
- cl_lock_put(env, lock);
- spin_lock(&head->coh_lock_guard);
- }
- spin_unlock(&head->coh_lock_guard);
- EXIT;
-}
-EXPORT_SYMBOL(cl_locks_prune);
-
-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 &&
- !(lock->cll_flags & CLF_CANCELLED)) {
- 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,
- const char *scope, const void *source)
-{
- struct cl_lock *lock;
- int rc;
- __u32 enqflags = need->cld_enq_flags;
-
- ENTRY;
- do {
- lock = cl_lock_hold_mutex(env, io, need, scope, source);
- if (IS_ERR(lock))
- break;
-
- rc = cl_enqueue_locked(env, lock, io, enqflags);
- if (rc == 0) {
- if (cl_lock_fits_into(env, lock, need, io)) {
- if (!(enqflags & CEF_AGL)) {
- cl_lock_mutex_put(env, lock);
- cl_lock_lockdep_acquire(env, lock,
- enqflags);
- break;
- }
- rc = 1;
- }
- cl_unuse_locked(env, lock);
- }
- cl_lock_trace(D_DLMTRACE, env,
- rc <= 0 ? "enqueue failed" : "agl succeed", 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);
- if (rc > 0) {
- LASSERT(enqflags & CEF_AGL);
- lock = NULL;
- } else if (rc != 0) {
- lock = ERR_PTR(rc);
- }
- } 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_get(lock);
- cl_lock_hold_mod(env, lock, +1);
- 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_trace(D_DLMTRACE, env, "release lock", lock);
- 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);
-
-void 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);
- if (lock->cll_users == 0)
- wake_up_all(&lock->cll_wq);
- EXIT;
-}
-EXPORT_SYMBOL(cl_lock_user_del);
-
-const char *cl_lock_mode_name(const enum cl_lock_mode mode)
-{
- static const char *names[] = {
- [CLM_PHANTOM] = "P",
- [CLM_READ] = "R",
- [CLM_WRITE] = "W",
- [CLM_GROUP] = "G"
- };
- CLASSERT(CLM_MAX == ARRAY_SIZE(names));
- return names[mode];
-}
-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);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff