Viewing: ldlm_lock.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2010, 2017, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Author: Peter Braam <braam@clusterfs.com>
* Author: Phil Schwan <phil@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_LDLM
#include <lustre_swab.h>
#include <obd_class.h>
#include "ldlm_internal.h"
struct kmem_cache *ldlm_glimpse_work_kmem;
EXPORT_SYMBOL(ldlm_glimpse_work_kmem);
/* lock types */
char *ldlm_lockname[] = {
[0] = "--",
[LCK_EX] = "EX",
[LCK_PW] = "PW",
[LCK_PR] = "PR",
[LCK_CW] = "CW",
[LCK_CR] = "CR",
[LCK_NL] = "NL",
[LCK_GROUP] = "GROUP",
[LCK_COS] = "COS",
[LCK_TXN] = "TXN"
};
EXPORT_SYMBOL(ldlm_lockname);
char *ldlm_typename[] = {
[LDLM_PLAIN] = "PLN",
[LDLM_EXTENT] = "EXT",
[LDLM_FLOCK] = "FLK",
[LDLM_IBITS] = "IBT",
};
static ldlm_policy_wire_to_local_t ldlm_policy_wire_to_local[] = {
[LDLM_PLAIN - LDLM_TYPE_MIN] = ldlm_plain_policy_wire_to_local,
[LDLM_EXTENT - LDLM_TYPE_MIN] = ldlm_extent_policy_wire_to_local,
[LDLM_FLOCK - LDLM_TYPE_MIN] = ldlm_flock_policy_wire_to_local,
[LDLM_IBITS - LDLM_TYPE_MIN] = ldlm_ibits_policy_wire_to_local,
};
static ldlm_policy_local_to_wire_t ldlm_policy_local_to_wire[] = {
[LDLM_PLAIN - LDLM_TYPE_MIN] = ldlm_plain_policy_local_to_wire,
[LDLM_EXTENT - LDLM_TYPE_MIN] = ldlm_extent_policy_local_to_wire,
[LDLM_FLOCK - LDLM_TYPE_MIN] = ldlm_flock_policy_local_to_wire,
[LDLM_IBITS - LDLM_TYPE_MIN] = ldlm_ibits_policy_local_to_wire,
};
/**
* Converts lock policy from local format to on the wire lock_desc format
*/
void ldlm_convert_policy_to_wire(enum ldlm_type type,
const union ldlm_policy_data *lpolicy,
union ldlm_wire_policy_data *wpolicy)
{
ldlm_policy_local_to_wire_t convert;
convert = ldlm_policy_local_to_wire[type - LDLM_TYPE_MIN];
convert(lpolicy, wpolicy);
}
/**
* Converts lock policy from on the wire lock_desc format to local format
*/
void ldlm_convert_policy_to_local(struct obd_export *exp, enum ldlm_type type,
const union ldlm_wire_policy_data *wpolicy,
union ldlm_policy_data *lpolicy)
{
ldlm_policy_wire_to_local_t convert;
convert = ldlm_policy_wire_to_local[type - LDLM_TYPE_MIN];
convert(wpolicy, lpolicy);
}
const char *ldlm_it2str(enum ldlm_intent_flags it)
{
switch (it) {
case IT_OPEN:
return "open";
case IT_CREAT:
return "creat";
case (IT_OPEN | IT_CREAT):
return "open|creat";
case IT_READDIR:
return "readdir";
case IT_GETATTR:
return "getattr";
case IT_LOOKUP:
return "lookup";
case IT_GETXATTR:
return "getxattr";
case IT_LAYOUT:
return "layout";
default:
CERROR("Unknown intent 0x%08x\n", it);
return "UNKNOWN";
}
}
EXPORT_SYMBOL(ldlm_it2str);
#ifdef CONFIG_LUSTRE_FS_SERVER
static ldlm_processing_policy ldlm_processing_policy_table[] = {
[LDLM_PLAIN] = ldlm_process_plain_lock,
[LDLM_EXTENT] = ldlm_process_extent_lock,
[LDLM_FLOCK] = ldlm_process_flock_lock,
[LDLM_IBITS] = ldlm_process_inodebits_lock,
};
ldlm_processing_policy ldlm_get_processing_policy(struct ldlm_resource *res)
{
return ldlm_processing_policy_table[res->lr_type];
}
EXPORT_SYMBOL(ldlm_get_processing_policy);
static ldlm_reprocessing_policy ldlm_reprocessing_policy_table[] = {
[LDLM_PLAIN] = ldlm_reprocess_queue,
[LDLM_EXTENT] = ldlm_reprocess_queue,
[LDLM_FLOCK] = ldlm_reprocess_queue,
[LDLM_IBITS] = ldlm_reprocess_inodebits_queue,
};
ldlm_reprocessing_policy ldlm_get_reprocessing_policy(struct ldlm_resource *res)
{
return ldlm_reprocessing_policy_table[res->lr_type];
}
#endif /* CONFIG_LUSTRE_FS_SERVER */
void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg)
{
ns->ns_policy = arg;
}
EXPORT_SYMBOL(ldlm_register_intent);
/* REFCOUNTED LOCK OBJECTS */
/**
* Get a reference on a lock.
*
* Lock refcounts, during creation:
* - one special one for allocation, dec'd only once in destroy
* - one for being a lock that's in-use
* - one for the addref associated with a new lock
*/
struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
{
refcount_inc(&lock->l_handle.h_ref);
return lock;
}
EXPORT_SYMBOL(ldlm_lock_get);
static void lock_handle_free(struct rcu_head *rcu)
{
struct ldlm_lock *lock = container_of(rcu, struct ldlm_lock,
l_handle.h_rcu);
OBD_FREE_PRE(lock, sizeof(*lock), "slab-freed");
kmem_cache_free(ldlm_lock_slab, lock);
}
/**
* Release lock reference.
*
* Also frees the lock if it was last reference.
*/
void ldlm_lock_put(struct ldlm_lock *lock)
{
ENTRY;
LASSERT(lock->l_resource != LP_POISON);
LASSERT(refcount_read(&lock->l_handle.h_ref) > 0);
if (refcount_dec_and_test(&lock->l_handle.h_ref)) {
struct ldlm_resource *res;
LDLM_DEBUG(lock,
"final lock_put on destroyed lock, freeing it.");
res = lock->l_resource;
LASSERT(lock->l_flags & LDLM_FL_DESTROYED);
LASSERT(list_empty(&lock->l_exp_list));
LASSERT(list_empty(&lock->l_res_link));
LASSERT(list_empty(&lock->l_pending_chain));
lprocfs_counter_decr(ldlm_res_to_ns(res)->ns_stats,
LDLM_NSS_LOCKS);
if (lock->l_export) {
class_export_lock_put(lock->l_export, lock);
lock->l_export = NULL;
}
if (lock->l_lvb_data != NULL)
OBD_FREE_LARGE(lock->l_lvb_data, lock->l_lvb_len);
if (res->lr_type == LDLM_IBITS && lock->l_ibits_node) {
OBD_SLAB_FREE_PTR(lock->l_ibits_node,
ldlm_inodebits_slab);
}
ldlm_resource_putref(res);
lock->l_resource = NULL;
if (lock->l_flags & BIT(63))
/* Performance testing - bypassing RCU removes overhead */
lock_handle_free(&lock->l_handle.h_rcu);
else
call_rcu(&lock->l_handle.h_rcu, lock_handle_free);
}
EXIT;
}
EXPORT_SYMBOL(ldlm_lock_put);
/**
* Removes LDLM lock \a lock from LRU. Assumes LRU is already locked.
*/
int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
{
struct ldlm_namespace *ns;
int rc = 0;
ns = ldlm_lock_to_ns(lock);
if (ns->ns_lock_cache_ops &&
ns->ns_lock_cache_ops->llco_remove_lock)
rc = ns->ns_lock_cache_ops->llco_remove_lock(ns, lock);
return rc;
}
/**
* Removes LDLM lock \a lock from LRU. Obtains the LRU lock first.
*
* If \a last_use is non-zero, it will remove the lock from LRU only if
* it matches lock's l_last_used.
*
* \retval 0 if \a last_use is set, the lock is not in LRU list or \a last_use
* doesn't match lock's l_last_used;
* otherwise, the lock hasn't been in the LRU list.
* \retval 1 the lock was in LRU list and removed.
*/
int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, ktime_t last_use,
bool reuse)
{
struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
int rc = 0;
ENTRY;
if ((lock->l_flags & LDLM_FL_NS_SRV)) {
LASSERT(list_empty(&lock->l_lru));
RETURN(0);
}
spin_lock(&ns->ns_lock);
if (!ktime_compare(last_use, ktime_set(0, 0)) ||
!ktime_compare(last_use, lock->l_last_used)) {
rc = ldlm_lock_remove_from_lru_nolock(lock);
if (rc && reuse) {
lprocfs_counter_incr(ns->ns_stats, LDLM_NSS_LRU_HITS);
if (lock->l_lru_type == LRU_PRIV)
lprocfs_counter_incr(ns->ns_stats,
LDLM_NSS_LRU_PRIV_HITS);
}
}
spin_unlock(&ns->ns_lock);
RETURN(rc);
}
/* Adds LDLM lock \a lock to namespace LRU. Assumes LRU is already locked. */
void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
{
struct ldlm_namespace *ns;
LASSERT(list_empty(&lock->l_lru));
LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
ns = ldlm_lock_to_ns(lock);
if (ns->ns_lock_cache_ops &&
ns->ns_lock_cache_ops->llco_add_lock)
ns->ns_lock_cache_ops->llco_add_lock(ns, lock);
}
/* Adds LDLM lock \a lock to namespace LRU. Obtains necessary LRU locks first */
static void ldlm_lock_add_to_lru(struct ldlm_lock *lock)
{
struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
ENTRY;
spin_lock(&ns->ns_lock);
ldlm_lock_add_to_lru_nolock(lock);
spin_unlock(&ns->ns_lock);
EXIT;
}
/**
* Moves LDLM lock \a lock that is already in namespace LRU to the tail of
* the LRU. Performs necessary LRU locking
*/
void ldlm_lock_touch_in_lru(struct ldlm_lock *lock)
{
struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
ENTRY;
if ((lock->l_flags & LDLM_FL_NS_SRV)) {
LASSERT(list_empty(&lock->l_lru));
EXIT;
return;
}
spin_lock(&ns->ns_lock);
if (!list_empty(&lock->l_lru)) {
ldlm_lock_remove_from_lru_nolock(lock);
ldlm_lock_add_to_lru_nolock(lock);
}
spin_unlock(&ns->ns_lock);
EXIT;
}
/**
* Helper to destroy a locked lock.
*
* Used by ldlm_lock_destroy and ldlm_lock_destroy_nolock
* Must be called with l_lock and lr_lock held.
*
* Does not actually free the lock data, but rather marks the lock as
* destroyed by setting l_destroyed field in the lock to 1. Destroys a
* handle->lock association too, so that the lock can no longer be found
* and removes the lock from LRU list. Actual lock freeing occurs when
* last lock reference goes away.
*
* Original comment (of some historical value):
* This used to have a 'strict' flag, which recovery would use to mark an
* in-use lock as needing-to-die. Lest I am ever tempted to put it back, I
* shall explain why it's gone: with the new hash table scheme, once you call
* ldlm_lock_destroy, you can never drop your final references on this lock.
* Because it's not in the hash table anymore. -phil
*/
static int ldlm_lock_destroy_internal(struct ldlm_lock *lock)
{
ENTRY;
if (lock->l_readers || lock->l_writers) {
LDLM_ERROR(lock, "lock still has references");
LBUG();
}
if (!list_empty(&lock->l_res_link)) {
LDLM_ERROR(lock, "lock still on resource");
LBUG();
}
if ((lock->l_flags & LDLM_FL_DESTROYED)) {
LASSERT(list_empty(&lock->l_lru));
EXIT;
return 0;
}
(lock->l_flags |= LDLM_FL_DESTROYED);
wake_up(&lock->l_waitq);
if (lock->l_export && lock->l_export->exp_lock_hash) {
/* Safe to call cfs_hash_del as lock isn't in exp_lock_hash. */
/* below, .hs_keycmp resolves to ldlm_export_lock_keycmp() */
cfs_hash_del(lock->l_export->exp_lock_hash,
&lock->l_remote_handle, &lock->l_exp_hash);
}
ldlm_lock_remove_from_lru(lock);
class_handle_unhash(&lock->l_handle);
EXIT;
return 1;
}
/* Destroys a LDLM lock \a lock. Performs necessary locking first. */
void ldlm_lock_destroy(struct ldlm_lock *lock)
{
int first;
ENTRY;
lock_res_and_lock(lock);
first = ldlm_lock_destroy_internal(lock);
unlock_res_and_lock(lock);
/* drop reference from hashtable only for first destroy */
if (first) {
ldlm_lock_put(lock);
}
EXIT;
}
/* Destroys a LDLM lock \a lock that is already locked. */
void ldlm_lock_destroy_nolock(struct ldlm_lock *lock)
{
int first;
ENTRY;
first = ldlm_lock_destroy_internal(lock);
/* drop reference from hashtable only for first destroy */
if (first) {
ldlm_lock_put(lock);
}
EXIT;
}
static const char lock_handle_owner[] = "ldlm";
/**
*
* Allocate and initialize new lock structure.
*
* usage: pass in a resource on which you have done ldlm_resource_get
* new lock will take over the refcount.
* returns: lock with refcount 2 - one for current caller and one for remote
*/
static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
{
struct ldlm_lock *lock;
ENTRY;
LASSERT(resource);
OBD_SLAB_ALLOC_PTR_GFP(lock, ldlm_lock_slab, GFP_NOFS);
if (lock == NULL)
RETURN(NULL);
RCU_INIT_POINTER(lock->l_resource, resource);
refcount_set(&lock->l_handle.h_ref, 2);
lock->l_lru_score = 0;
lock->l_lru_type = LRU_NORMAL_LIST;
INIT_LIST_HEAD(&lock->l_res_link);
INIT_LIST_HEAD(&lock->l_lru);
INIT_LIST_HEAD(&lock->l_pending_chain);
INIT_LIST_HEAD(&lock->l_bl_ast);
INIT_LIST_HEAD(&lock->l_cp_ast);
INIT_LIST_HEAD(&lock->l_rk_ast);
init_waitqueue_head(&lock->l_waitq);
lock->l_blocking_lock = NULL;
switch (resource->lr_type) {
case LDLM_IBITS:
case LDLM_PLAIN:
INIT_LIST_HEAD(&lock->l_sl_mode);
INIT_LIST_HEAD(&lock->l_sl_policy);
break;
case LDLM_FLOCK:
INIT_HLIST_NODE(&lock->l_exp_flock_hash);
RB_CLEAR_NODE(&lock->l_fl_rb);
break;
case LDLM_EXTENT:
RB_CLEAR_NODE(&lock->l_rb);
INIT_LIST_HEAD(&lock->l_same_extent);
break;
case LDLM_TYPE_END:
break;
}
INIT_HLIST_NODE(&lock->l_exp_hash);
lprocfs_counter_incr(ldlm_res_to_ns(resource)->ns_stats,
LDLM_NSS_LOCKS);
INIT_HLIST_NODE(&lock->l_handle.h_link);
class_handle_hash(&lock->l_handle, lock_handle_owner);
lock->l_callback_timestamp = 0;
lock->l_activity = 0;
#if LUSTRE_TRACKS_LOCK_EXP_REFS
INIT_LIST_HEAD(&lock->l_exp_refs_link);
lock->l_exp_refs_nr = 0;
lock->l_exp_refs_target = NULL;
#endif
INIT_LIST_HEAD(&lock->l_exp_list);
RETURN(lock);
}
struct ldlm_lock *ldlm_lock_new_testing(struct ldlm_resource *resource)
{
struct ldlm_lock *lock = ldlm_lock_new(resource);
int rc;
if (!lock)
return NULL;
lock->l_flags |= BIT(63);
switch (resource->lr_type) {
case LDLM_IBITS:
rc = ldlm_inodebits_alloc_lock(lock);
break;
default:
rc = 0;
}
if (!rc)
return lock;
ldlm_lock_destroy(lock);
ldlm_lock_put(lock);
return NULL;
}
EXPORT_SYMBOL(ldlm_lock_new_testing);
/**
* Moves LDLM lock \a lock to another resource.
* This is used on client when server returns some other lock than requested
* (typically as a result of intent operation)
*/
int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock,
const struct ldlm_res_id *new_resid)
{
struct ldlm_resource *oldres;
struct ldlm_resource *newres;
int type;
ENTRY;
LASSERT(ns_is_client(ns));
oldres = lock_res_and_lock(lock);
if (memcmp(new_resid, &oldres->lr_name,
sizeof(oldres->lr_name)) == 0) {
/* Nothing to do */
unlock_res_and_lock(lock);
RETURN(0);
}
LASSERT(new_resid->name[0] != 0);
/* This function assumes that the lock isn't on any lists */
LASSERT(list_empty(&lock->l_res_link));
type = oldres->lr_type;
unlock_res_and_lock(lock);
newres = ldlm_resource_get(ns, new_resid, type, 1);
if (IS_ERR(newres))
RETURN(PTR_ERR(newres));
/*
* To flip the lock from the old to the new resource, oldres
* and newres have to be locked. Resource spin-locks are taken
* in the memory address order to avoid dead-locks.
*/
rcu_read_lock();
while (1) {
oldres = rcu_dereference(lock->l_resource);
if (oldres == newres)
break;
if (oldres < newres) {
lock_res(oldres);
lock_res_nested(newres, LRT_NEW);
} else {
lock_res(newres);
lock_res_nested(oldres, LRT_NEW);
}
if (lock->l_resource == oldres) {
rcu_assign_pointer(lock->l_resource, newres);
unlock_res(oldres);
unlock_res(newres);
break;
}
unlock_res(oldres);
unlock_res(newres);
}
rcu_read_unlock();
/* ...and the flowers are still standing! */
ldlm_resource_putref(oldres);
RETURN(0);
}
/** \defgroup ldlm_handles LDLM HANDLES
* Ways to get hold of locks without any addresses.
* @{
*/
/**
* Fills in handle for LDLM lock \a lock into supplied \a lockh
* Does not take any references.
*/
void ldlm_lock2handle(const struct ldlm_lock *lock, struct lustre_handle *lockh)
{
lockh->cookie = lock->l_handle.h_cookie;
}
EXPORT_SYMBOL(ldlm_lock2handle);
/**
* Obtain a lock reference by handle.
*
* if \a flags: atomically get the lock and set the flags.
* Return NULL if flag already set
*/
struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *handle,
__u64 flags)
{
struct ldlm_lock *lock;
ENTRY;
LASSERT(handle);
if (!lustre_handle_is_used(handle))
RETURN(NULL);
lock = class_handle2object(handle->cookie, lock_handle_owner);
if (lock == NULL)
RETURN(NULL);
if (lock->l_export != NULL && lock->l_export->exp_failed) {
CDEBUG(D_INFO, "lock export failed: lock %p, exp %p\n",
lock, lock->l_export);
ldlm_lock_put(lock);
RETURN(NULL);
}
/* It's unlikely but possible that someone marked the lock as
* destroyed after we did handle2object on it
*/
if ((flags == 0) && !(lock->l_flags & LDLM_FL_DESTROYED))
RETURN(lock);
lock_res_and_lock(lock);
LASSERT(lock->l_resource != NULL);
if (unlikely((lock->l_flags & LDLM_FL_DESTROYED))) {
unlock_res_and_lock(lock);
CDEBUG(D_INFO, "lock already destroyed: lock %p\n", lock);
ldlm_lock_put(lock);
RETURN(NULL);
}
/* If we're setting flags, make sure none of them are already set. */
if (flags != 0) {
if ((lock->l_flags & flags) != 0) {
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
RETURN(NULL);
}
lock->l_flags |= flags;
}
unlock_res_and_lock(lock);
RETURN(lock);
}
EXPORT_SYMBOL(__ldlm_handle2lock);
/** @} ldlm_handles */
/**
* Fill in "on the wire" representation for given LDLM lock into supplied
* lock descriptor \a desc structure.
*/
void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
{
ldlm_res2desc(lock->l_resource, &desc->l_resource);
desc->l_req_mode = lock->l_req_mode;
desc->l_granted_mode = lock->l_granted_mode;
ldlm_convert_policy_to_wire(lock->l_resource->lr_type,
&lock->l_policy_data,
&desc->l_policy_data);
}
/**
* Add a lock to list of conflicting locks to send AST to.
*
* Only add if we have not sent a blocking AST to the lock yet.
*/
static void ldlm_add_bl_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
struct list_head *work_list)
{
if (!(lock->l_flags & LDLM_FL_AST_SENT)) {
LDLM_DEBUG(lock, "lock incompatible; sending blocking AST.");
(lock->l_flags |= LDLM_FL_AST_SENT);
/* If the enqueuing client said so, tell the AST recipient to
* discard dirty data, rather than writing back.
*/
if ((new->l_flags & LDLM_FL_AST_DISCARD_DATA))
(lock->l_flags |= LDLM_FL_DISCARD_DATA);
/* Lock can be converted from a blocking state back to granted
* after lock convert or COS downgrade but still be in an
* older bl_list because it is controlled only by
* ldlm_work_bl_ast_lock(), let it be processed there.
*/
if (list_empty(&lock->l_bl_ast)) {
list_add(&lock->l_bl_ast, work_list);
ldlm_lock_get(lock);
}
LASSERT(lock->l_blocking_lock == NULL);
lock->l_blocking_lock = ldlm_lock_get(new);
}
}
/* Add a lock to list of just granted locks to send completion AST to. */
static void ldlm_add_cp_work_item(struct ldlm_lock *lock,
struct list_head *work_list)
{
if (!(lock->l_flags & LDLM_FL_CP_REQD)) {
(lock->l_flags |= LDLM_FL_CP_REQD);
LDLM_DEBUG(lock, "lock granted; sending completion AST.");
LASSERT(list_empty(&lock->l_cp_ast));
list_add(&lock->l_cp_ast, work_list);
ldlm_lock_get(lock);
}
}
/**
* Aggregator function to add AST work items into a list. Determines
* what sort of an AST work needs to be done and calls the proper
* adding function.
* Must be called with lr_lock held.
*/
void ldlm_add_ast_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
struct list_head *work_list)
{
ENTRY;
check_res_locked(lock->l_resource);
if (new)
ldlm_add_bl_work_item(lock, new, work_list);
else
ldlm_add_cp_work_item(lock, work_list);
EXIT;
}
/**
* Add specified reader/writer reference to LDLM lock with handle \a lockh.
* r/w reference type is determined by \a mode
* Calls ldlm_lock_addref_internal.
*/
void ldlm_lock_addref(const struct lustre_handle *lockh, enum ldlm_mode mode)
{
struct ldlm_lock *lock;
lock = ldlm_handle2lock(lockh);
LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
ldlm_lock_addref_internal(lock, mode);
ldlm_lock_put(lock);
}
EXPORT_SYMBOL(ldlm_lock_addref);
/**
* Helper function.
* Add specified reader/writer reference to LDLM lock \a lock.
* r/w reference type is determined by \a mode
* Removes lock from LRU if it is there.
* Assumes the LDLM lock is already locked.
*/
void ldlm_lock_addref_internal_nolock(struct ldlm_lock *lock,
enum ldlm_mode mode)
{
ldlm_lock_remove_from_lru_check(lock, ktime_set(0, 0), true);
if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
lock->l_readers++;
}
if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS | LCK_TXN)) {
lock->l_writers++;
}
ldlm_lock_get(lock);
lock->l_last_used = ktime_get();
LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
}
/**
* Attempts to add reader/writer reference to a lock with handle \a lockh, and
* fails if lock is already LDLM_FL_CBPENDING or destroyed.
*
* \retval 0 success, lock was addref-ed
*
* \retval -EAGAIN lock is being canceled.
*/
int ldlm_lock_addref_try(const struct lustre_handle *lockh, enum ldlm_mode mode)
{
struct ldlm_lock *lock;
int result;
result = -EAGAIN;
lock = ldlm_handle2lock(lockh);
if (lock != NULL) {
lock_res_and_lock(lock);
if (lock->l_readers != 0 || lock->l_writers != 0 ||
!(lock->l_flags & LDLM_FL_CBPENDING)) {
ldlm_lock_addref_internal_nolock(lock, mode);
result = 0;
}
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
}
return result;
}
EXPORT_SYMBOL(ldlm_lock_addref_try);
/**
* Add specified reader/writer reference to LDLM lock \a lock.
* Locks LDLM lock and calls ldlm_lock_addref_internal_nolock to do the work.
* Only called for local locks.
*/
void ldlm_lock_addref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
{
lock_res_and_lock(lock);
ldlm_lock_addref_internal_nolock(lock, mode);
unlock_res_and_lock(lock);
}
/**
* Removes reader/writer reference for LDLM lock \a lock.
* Assumes LDLM lock is already locked.
* only called in ldlm_flock_destroy and for local locks.
* Does NOT add lock to LRU if no r/w references left to accomodate flock locks
* that cannot be placed in LRU.
*/
void ldlm_lock_decref_internal_nolock(struct ldlm_lock *lock,
enum ldlm_mode mode)
{
LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
LASSERT(lock->l_readers > 0);
lock->l_readers--;
}
if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS | LCK_TXN)) {
LASSERT(lock->l_writers > 0);
lock->l_writers--;
}
ldlm_lock_put(lock); /* matches the LDLM_LOCK_GET() in addref */
}
/**
* Removes reader/writer reference for LDLM lock \a lock.
* Locks LDLM lock first.
* If the lock is determined to be client lock on a client and r/w refcount
* drops to zero and the lock is not blocked, the lock is added to LRU lock
* on the namespace.
* For blocked LDLM locks if r/w count drops to zero, blocking_ast is called.
*/
void ldlm_lock_decref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
{
struct ldlm_namespace *ns;
ENTRY;
lock_res_and_lock(lock);
ns = ldlm_lock_to_ns(lock);
ldlm_lock_decref_internal_nolock(lock, mode);
if (((lock->l_flags & LDLM_FL_LOCAL) || lock->l_req_mode == LCK_GROUP) &&
!lock->l_readers && !lock->l_writers) {
/* If this is a local lock on a server namespace and this was
* the last reference, cancel the lock.
*
* Group locks are special:
* They must not go in LRU, but they are not called back
* like non-group locks, instead they are manually released.
* They have an l_writers reference which they keep until
* they are manually released, so we remove them when they have
* no more reader or writer references. - LU-6368
*/
lock->l_flags |= LDLM_FL_CBPENDING;
}
if (!lock->l_readers && !lock->l_writers && (lock->l_flags & LDLM_FL_CBPENDING)) {
unsigned int mask = D_DLMTRACE;
/* If we received a blocked AST and this was the last reference,
* run the callback.
*/
if ((lock->l_flags & LDLM_FL_NS_SRV) && lock->l_export)
mask |= D_WARNING;
LDLM_DEBUG_LIMIT(mask, lock,
"final decref done on %sCBPENDING lock",
mask & D_WARNING ? "non-local " : "");
ldlm_lock_get(lock); /* dropped by bl thread */
ldlm_lock_remove_from_lru(lock);
unlock_res_and_lock(lock);
if ((lock->l_flags & LDLM_FL_FAIL_LOC))
CFS_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
if ((lock->l_flags & LDLM_FL_ATOMIC_CB) ||
((lock->l_flags & LDLM_FL_LOCAL) &&
!(lock->l_flags & LDLM_FL_AST_DISCARD_DATA)) ||
ldlm_bl_to_thread_lock(ns, NULL, lock) != 0)
ldlm_handle_bl_callback(ns, NULL, lock);
} else if (ns_is_client(ns) &&
!lock->l_readers && !lock->l_writers &&
!(lock->l_flags & LDLM_FL_NO_LRU) &&
!(lock->l_flags & LDLM_FL_BL_AST) &&
!(lock->l_flags & LDLM_FL_CONVERTING)) {
/* If this is a client-side namespace and this was the last
* reference, put it on the LRU.
*/
ldlm_lock_add_to_lru(lock);
unlock_res_and_lock(lock);
LDLM_DEBUG(lock, "add lock into lru list");
if ((lock->l_flags & LDLM_FL_FAIL_LOC))
CFS_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
ldlm_pool_recalc(&ns->ns_pool, true);
} else {
LDLM_DEBUG(lock, "do not add lock into lru list");
unlock_res_and_lock(lock);
}
EXIT;
}
/**
* Decrease reader/writer refcount for LDLM lock with handle \a lockh
*/
void ldlm_lock_decref(const struct lustre_handle *lockh, enum ldlm_mode mode)
{
struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
ldlm_lock_decref_internal(lock, mode);
ldlm_lock_put(lock);
}
EXPORT_SYMBOL(ldlm_lock_decref);
/**
* Decrease reader/writer refcount for LDLM lock with handle
* \a lockh and mark it for subsequent cancellation once r/w refcount
* drops to zero instead of putting into LRU.
*
*/
void ldlm_lock_decref_and_cancel(const struct lustre_handle *lockh,
enum ldlm_mode mode)
{
struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
ENTRY;
LASSERT(lock != NULL);
LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
lock_res_and_lock(lock);
(lock->l_flags |= LDLM_FL_CBPENDING);
unlock_res_and_lock(lock);
ldlm_lock_decref_internal(lock, mode);
ldlm_lock_put(lock);
}
EXPORT_SYMBOL(ldlm_lock_decref_and_cancel);
struct sl_insert_point {
struct list_head *res_link;
struct list_head *mode_link;
struct list_head *policy_link;
};
/**
* Finds a position to insert the new lock into granted lock list.
*
* Used for locks eligible for skiplist optimization.
*
* Parameters:
* queue [input]: the granted list where search acts on;
* req [input]: the lock whose position to be located;
* prev [output]: positions within 3 lists to insert @req to
* Return Value:
* filled @prev
* NOTE: called by
* - ldlm_grant_lock_with_skiplist
*/
static void search_granted_lock(struct list_head *queue,
struct ldlm_lock *req,
struct sl_insert_point *prev)
{
struct ldlm_lock *lock, *mode_end, *policy_end;
ENTRY;
list_for_each_entry(lock, queue, l_res_link) {
mode_end = list_entry(lock->l_sl_mode.prev,
struct ldlm_lock, l_sl_mode);
if (lock->l_req_mode != req->l_req_mode) {
/* jump to last lock of mode group */
lock = mode_end;
continue;
}
/* suitable mode group is found */
if (lock->l_resource->lr_type == LDLM_PLAIN) {
/* insert point is last lock of the mode group */
prev->res_link = &mode_end->l_res_link;
prev->mode_link = &mode_end->l_sl_mode;
prev->policy_link = &req->l_sl_policy;
EXIT;
return;
} else if (lock->l_resource->lr_type == LDLM_IBITS) {
for (;;) {
policy_end =
list_entry(lock->l_sl_policy.prev,
struct ldlm_lock,
l_sl_policy);
if (lock->l_policy_data.l_inodebits.bits ==
req->l_policy_data.l_inodebits.bits) {
/* inserting last lock of policy grp */
prev->res_link =
&policy_end->l_res_link;
prev->mode_link =
&policy_end->l_sl_mode;
prev->policy_link =
&policy_end->l_sl_policy;
EXIT;
return;
}
if (policy_end == mode_end)
/* done with mode group */
break;
/* go to next policy group within mode group */
lock = list_next_entry(policy_end, l_res_link);
} /* loop over policy groups within the mode group */
/* insert point is last lock of the mode group,
* new policy group is started
*/
prev->res_link = &mode_end->l_res_link;
prev->mode_link = &mode_end->l_sl_mode;
prev->policy_link = &req->l_sl_policy;
EXIT;
return;
}
LDLM_ERROR(lock, "is not LDLM_PLAIN or LDLM_IBITS lock");
LBUG();
}
/* insert point is last lock on the queue,
* new mode group and new policy group are started
*/
prev->res_link = queue->prev;
prev->mode_link = &req->l_sl_mode;
prev->policy_link = &req->l_sl_policy;
EXIT;
}
/**
* Add a lock into resource granted list after a position described by
* \a prev.
*/
static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
struct sl_insert_point *prev)
{
struct ldlm_resource *res = lock->l_resource;
ENTRY;
check_res_locked(res);
ldlm_resource_dump(D_INFO, res);
LDLM_DEBUG(lock, "About to add lock:");
if ((lock->l_flags & LDLM_FL_DESTROYED)) {
CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
return;
}
LASSERT(list_empty(&lock->l_res_link));
LASSERT(list_empty(&lock->l_sl_mode));
LASSERT(list_empty(&lock->l_sl_policy));
/*
* lock->link == prev->link means lock is first starting the group.
* Don't re-add to itself to suppress kernel warnings.
*/
if (&lock->l_res_link != prev->res_link)
list_add(&lock->l_res_link, prev->res_link);
if (&lock->l_sl_mode != prev->mode_link)
list_add(&lock->l_sl_mode, prev->mode_link);
if (&lock->l_sl_policy != prev->policy_link)
list_add(&lock->l_sl_policy, prev->policy_link);
EXIT;
}
/**
* Add a lock to granted list on a resource maintaining skiplist
* correctness.
*/
void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
{
struct sl_insert_point prev;
LASSERT(ldlm_is_granted(lock));
search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
ldlm_granted_list_add_lock(lock, &prev);
}
/**
* Perform lock granting bookkeeping.
*
* Includes putting the lock into granted list and updating lock mode.
* NOTE: called by
* - ldlm_lock_enqueue
* - ldlm_reprocess_queue
*
* must be called with lr_lock held
*/
void ldlm_grant_lock(struct ldlm_lock *lock, struct list_head *work_list)
{
struct ldlm_resource *res = lock->l_resource;
ENTRY;
check_res_locked(res);
lock->l_granted_mode = lock->l_req_mode;
if (work_list && lock->l_completion_ast != NULL)
ldlm_add_ast_work_item(lock, NULL, work_list);
if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS)
ldlm_grant_lock_with_skiplist(lock);
else if (res->lr_type == LDLM_EXTENT)
ldlm_extent_add_lock(res, lock);
else if (res->lr_type == LDLM_FLOCK) {
/* We should not add locks to granted list in the following
* cases:
* - this is an UNLOCK but not a real lock;
* - this is a TEST lock;
* - this is a F_CANCELLK lock (async flock has req_mode == 0)
* - this is a deadlock (flock cannot be granted)
*/
if (lock->l_req_mode == 0 ||
lock->l_req_mode == LCK_NL ||
(lock->l_flags & LDLM_FL_TEST_LOCK) ||
(lock->l_flags & LDLM_FL_FLOCK_DEADLOCK))
RETURN_EXIT;
ldlm_flock_add_lock(res, &res->lr_granted, lock);
} else {
LBUG();
}
ldlm_pool_add(&ldlm_res_to_ns(res)->ns_pool, lock);
EXIT;
}
/**
* Check if the given @lock meets the criteria for a match.
* A reference on the lock is taken if matched.
*
* @lock test-against this lock
* @data parameters
*
* RETURN returns true if @lock matches @data, false otherwise
*/
static bool lock_matches(struct ldlm_lock *lock, void *vdata)
{
struct ldlm_match_data *data = vdata;
union ldlm_policy_data *lpol = &lock->l_policy_data;
enum ldlm_mode match = LCK_MODE_MIN;
if (lock == data->lmd_old)
return true;
/* Check if this lock can be matched.
* Used by LU-2919(exclusive open) for open lease lock
*/
if (lock->l_flags & LDLM_FL_EXCL)
return false;
/* llite sometimes wants to match locks that will be
* canceled when their users drop, but we allow it to match
* if it passes in CBPENDING and the lock still has users.
* this is generally only going to be used by children
* whose parents already hold a lock so forward progress
* can still happen.
*/
if ((lock->l_flags & LDLM_FL_CBPENDING) &&
!(data->lmd_flags & LDLM_FL_CBPENDING) &&
!(data->lmd_match & LDLM_MATCH_GROUP))
return false;
if (!(data->lmd_match & (LDLM_MATCH_UNREF | LDLM_MATCH_GROUP)) &&
(lock->l_flags & LDLM_FL_CBPENDING) &&
lock->l_readers == 0 && lock->l_writers == 0)
return false;
if (data->lmd_match & LDLM_MATCH_SKIP_UNUSED &&
lock->l_readers == 0 && lock->l_writers == 0)
return false;
if (!(lock->l_req_mode & *data->lmd_mode))
return false;
/* When we search for ast_data, we are not doing a traditional match,
* so we don't worry about IBITS or extent matching.
*/
if (data->lmd_match & (LDLM_MATCH_AST | LDLM_MATCH_AST_ANY)) {
if (!lock->l_ast_data)
return false;
if (data->lmd_match & LDLM_MATCH_AST_ANY)
goto matched;
}
match = lock->l_req_mode;
switch (lock->l_resource->lr_type) {
case LDLM_EXTENT:
if (!(data->lmd_match & LDLM_MATCH_RIGHT) &&
(lpol->l_extent.start > data->lmd_policy->l_extent.start ||
lpol->l_extent.end < data->lmd_policy->l_extent.end))
return false;
if (unlikely(match == LCK_GROUP) &&
data->lmd_policy->l_extent.gid != LDLM_GID_ANY &&
lpol->l_extent.gid != data->lmd_policy->l_extent.gid)
return false;
break;
case LDLM_IBITS:
/* We match with existing lock with same or wider set of bits */
if ((lpol->l_inodebits.bits &
data->lmd_policy->l_inodebits.bits) !=
data->lmd_policy->l_inodebits.bits)
return false;
if (unlikely(match == LCK_GROUP) &&
data->lmd_policy->l_inodebits.li_gid != LDLM_GID_ANY &&
lpol->l_inodebits.li_gid !=
data->lmd_policy->l_inodebits.li_gid)
return false;
break;
default:
break;
}
/* We match if we have existing lock with same or wider set of bits. */
if (!(data->lmd_match & LDLM_MATCH_UNREF) && LDLM_HAVE_MASK(lock, GONE))
return false;
if (!equi(data->lmd_flags & LDLM_FL_LOCAL_ONLY,
(lock->l_flags & LDLM_FL_LOCAL)))
return false;
/* Filter locks by skipping flags */
if (data->lmd_skip_flags & lock->l_flags)
return false;
matched:
/**
* In case the lock is a CBPENDING grouplock, just pin it and return,
* we need to wait until it gets to DESTROYED.
*/
if ((data->lmd_flags & LDLM_FL_TEST_LOCK) ||
((lock->l_flags & LDLM_FL_CBPENDING) &&
(data->lmd_match & LDLM_MATCH_GROUP))) {
ldlm_lock_get(lock);
ldlm_lock_touch_in_lru(lock);
} else {
ldlm_lock_addref_internal_nolock(lock, match);
}
*data->lmd_mode = match;
data->lmd_lock = lock;
return true;
}
/**
* Search for a lock with given parameters in interval trees.
*
* \param res search for a lock in this resource
* \param data parameters
*
* \retval a referenced lock or NULL.
*/
struct ldlm_lock *search_itree(struct ldlm_resource *res,
struct ldlm_match_data *data)
{
int idx;
__u64 end = data->lmd_policy->l_extent.end;
data->lmd_lock = NULL;
if (data->lmd_match & LDLM_MATCH_RIGHT)
end = OBD_OBJECT_EOF;
for (idx = 0; idx < LCK_MODE_NUM; idx++) {
struct ldlm_interval_tree *tree = &res->lr_itree[idx];
if (RB_EMPTY_ROOT(&tree->lit_root.rb_root))
continue;
if (!(tree->lit_mode & *data->lmd_mode))
continue;
ldlm_extent_search(&tree->lit_root,
data->lmd_policy->l_extent.start,
end,
lock_matches, data);
if (data->lmd_lock)
return data->lmd_lock;
}
return NULL;
}
EXPORT_SYMBOL(search_itree);
/**
* Search for a lock with given properties in a queue.
*
* \param queue search for a lock in this queue
* \param data parameters
*
* \retval a referenced lock or NULL.
*/
static struct ldlm_lock *search_queue(struct list_head *queue,
struct ldlm_match_data *data)
{
struct ldlm_lock *lock;
data->lmd_lock = NULL;
list_for_each_entry(lock, queue, l_res_link)
if (lock_matches(lock, data))
return data->lmd_lock;
return NULL;
}
void ldlm_lock_fail_match_locked(struct ldlm_lock *lock)
{
if ((lock->l_flags & LDLM_FL_FAIL_NOTIFIED) == 0) {
lock->l_flags |= LDLM_FL_FAIL_NOTIFIED;
wake_up(&lock->l_waitq);
}
}
EXPORT_SYMBOL(ldlm_lock_fail_match_locked);
/**
* Mark lock as "matchable" by OST.
*
* Used to prevent certain races in LOV/OSC where the lock is granted, but LVB
* is not yet valid.
* Assumes LDLM lock is already locked.
*/
void ldlm_lock_allow_match_locked(struct ldlm_lock *lock)
{
lock->l_flags |= LDLM_FL_LVB_READY;
wake_up(&lock->l_waitq);
}
EXPORT_SYMBOL(ldlm_lock_allow_match_locked);
/**
* Mark lock as "matchable" by OST.
* Locks the lock and then \see ldlm_lock_allow_match_locked
*/
void ldlm_lock_allow_match(struct ldlm_lock *lock)
{
lock_res_and_lock(lock);
ldlm_lock_allow_match_locked(lock);
unlock_res_and_lock(lock);
}
EXPORT_SYMBOL(ldlm_lock_allow_match);
/**
* Attempt to find a lock with specified properties.
*
* Typically returns a reference to matched lock unless LDLM_FL_TEST_LOCK is
* set in \a flags
*
* Can be called in two ways:
*
* If 'ns' is NULL, then lockh describes an existing lock that we want to look
* for a duplicate of.
*
* Otherwise, all of the fields must be filled in, to match against.
*
* If 'flags' contains LDLM_FL_LOCAL_ONLY, then only match local locks on the
* server (ie, connh is NULL)
* If 'flags' contains LDLM_FL_BLOCK_GRANTED, then only locks on the granted
* list will be considered
* If 'flags' contains LDLM_FL_CBPENDING, then locks that have been marked
* to be canceled can still be matched as long as they still have reader
* or writer refernces
* If 'flags' contains LDLM_FL_TEST_LOCK, then don't actually reference a lock,
* just tell us if we would have matched.
*
* If @match_flags contains LDLM_MATCH_UNREF, then we don't match unreferenced
* locks
* If @match_flags contains LDLM_MATCH_AST, then we don't match lock without
* ast_data
* If @match_flags contains LDLM_MATCH_AST_ANY, then we'd match lock with
* ast_data
* If @match_flags contains LDLM_MATCH_RIGHT, then we'd match extent lock at
* the right region for the desired lock
* If @match_flags contains LDLM_MATCH_GROUP, then we'd match group lock
* If @match_flags contains LDLM_MATCH_SKIP_UNUSED, then we don't match any
* unused locks
*
* \retval 1 if it finds an already-existing lock that is compatible; in this
* case, lockh is filled in with a addref()ed lock
*
* We also check security context, and if that fails we simply return 0 (to
* keep caller code unchanged), the context failure will be discovered by
* caller sometime later.
*/
enum ldlm_mode ldlm_lock_match_with_skip(struct ldlm_namespace *ns,
__u64 flags, __u64 skip_flags,
const struct ldlm_res_id *res_id,
enum ldlm_type type,
union ldlm_policy_data *policy,
enum ldlm_mode mode,
enum ldlm_match_flags match_flags,
struct lustre_handle *lockh)
{
struct ldlm_match_data data = {
.lmd_old = NULL,
.lmd_lock = NULL,
.lmd_mode = &mode,
.lmd_policy = policy,
.lmd_flags = flags,
.lmd_skip_flags = skip_flags,
.lmd_match = match_flags,
};
struct ldlm_resource *res;
struct ldlm_lock *lock;
struct ldlm_lock *group_lock;
int matched;
ENTRY;
if (ns == NULL) {
data.lmd_old = ldlm_handle2lock(lockh);
LASSERT(data.lmd_old != NULL);
ns = ldlm_lock_to_ns(data.lmd_old);
res_id = &data.lmd_old->l_resource->lr_name;
type = data.lmd_old->l_resource->lr_type;
*data.lmd_mode = data.lmd_old->l_req_mode;
}
res = ldlm_resource_get(ns, res_id, type, 0);
if (IS_ERR(res)) {
LASSERT(data.lmd_old == NULL);
RETURN(0);
}
repeat:
group_lock = NULL;
lock_res(res);
if (res->lr_type == LDLM_EXTENT)
lock = search_itree(res, &data);
else
lock = search_queue(&res->lr_granted, &data);
if (!lock && !(flags & LDLM_FL_BLOCK_GRANTED))
lock = search_queue(&res->lr_waiting, &data);
matched = lock ? mode : 0;
if (lock && (lock->l_flags & LDLM_FL_CBPENDING) &&
(data.lmd_match & LDLM_MATCH_GROUP))
group_lock = lock;
unlock_res(res);
if (group_lock) {
l_wait_event_abortable(group_lock->l_waitq,
(lock->l_flags & LDLM_FL_DESTROYED));
ldlm_lock_put(lock);
goto repeat;
}
ldlm_resource_putref(res);
if (lock) {
ldlm_lock2handle(lock, lockh);
if ((flags & LDLM_FL_LVB_READY) &&
(!(lock->l_flags & LDLM_FL_LVB_READY))) {
__u64 wait_flags = LDLM_FL_LVB_READY |
LDLM_FL_DESTROYED | LDLM_FL_FAIL_NOTIFIED;
if (lock->l_completion_ast) {
int err = lock->l_completion_ast(lock,
LDLM_FL_WAIT_NOREPROC,
NULL);
if (err)
GOTO(out_fail_match, matched = 0);
}
wait_event_idle_timeout(
lock->l_waitq,
lock->l_flags & wait_flags,
cfs_time_seconds(obd_timeout));
if (!(lock->l_flags & LDLM_FL_LVB_READY))
GOTO(out_fail_match, matched = 0);
}
/* check user's security context */
if (lock->l_conn_export &&
sptlrpc_import_check_ctx(
class_exp2cliimp(lock->l_conn_export)))
GOTO(out_fail_match, matched = 0);
LDLM_DEBUG(lock, "matched (%llu %llu)",
(type == LDLM_PLAIN || type == LDLM_IBITS) ?
res_id->name[2] : policy->l_extent.start,
(type == LDLM_PLAIN || type == LDLM_IBITS) ?
res_id->name[3] : policy->l_extent.end);
out_fail_match:
if (flags & LDLM_FL_TEST_LOCK)
ldlm_lock_put(lock);
else if (!matched)
ldlm_lock_decref_internal(lock, mode);
}
/* less verbose for test-only */
if (!matched && !(flags & LDLM_FL_TEST_LOCK)) {
LDLM_DEBUG_NOLOCK("not matched ns %p type %u mode %u res %llu/%llu (%llu %llu)",
ns,
type, mode, res_id->name[0], res_id->name[1],
(type == LDLM_PLAIN || type == LDLM_IBITS) ?
res_id->name[2] : policy->l_extent.start,
(type == LDLM_PLAIN || type == LDLM_IBITS) ?
res_id->name[3] : policy->l_extent.end);
}
if (data.lmd_old != NULL)
ldlm_lock_put(data.lmd_old);
return matched;
}
EXPORT_SYMBOL(ldlm_lock_match_with_skip);
enum ldlm_mode ldlm_revalidate_lock_handle(const struct lustre_handle *lockh,
enum mds_ibits_locks *bits)
{
struct ldlm_lock *lock;
enum ldlm_mode mode = 0;
ENTRY;
lock = ldlm_handle2lock(lockh);
if (lock != NULL) {
lock_res_and_lock(lock);
if (LDLM_HAVE_MASK(lock, GONE))
GOTO(out, mode);
if ((lock->l_flags & LDLM_FL_CBPENDING) &&
lock->l_readers == 0 && lock->l_writers == 0)
GOTO(out, mode);
if (bits)
*bits = lock->l_policy_data.l_inodebits.bits;
mode = lock->l_granted_mode;
ldlm_lock_addref_internal_nolock(lock, mode);
}
EXIT;
out:
if (lock != NULL) {
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
}
return mode;
}
EXPORT_SYMBOL(ldlm_revalidate_lock_handle);
/** The caller must guarantee that the buffer is large enough. */
int ldlm_fill_lvb(struct ldlm_lock *lock, struct req_capsule *pill,
enum req_location loc, void *data, int lvb_len)
{
void *lvb;
ENTRY;
LASSERT(data != NULL);
LASSERT(lvb_len >= 0);
switch (lock->l_lvb_type) {
case LVB_T_OST:
if (lvb_len == sizeof(struct ost_lvb)) {
if (loc == RCL_CLIENT)
lvb = req_capsule_client_swab_get(pill,
&RMF_DLM_LVB,
lustre_swab_ost_lvb);
else
lvb = req_capsule_server_swab_get(pill,
&RMF_DLM_LVB,
lustre_swab_ost_lvb);
if (unlikely(lvb == NULL)) {
LDLM_ERROR(lock, "no LVB");
RETURN(-EPROTO);
}
memcpy(data, lvb, lvb_len);
} else if (lvb_len == sizeof(struct ost_lvb_v1)) {
struct ost_lvb *olvb = data;
if (loc == RCL_CLIENT)
lvb = req_capsule_client_swab_get(pill,
&RMF_DLM_LVB,
lustre_swab_ost_lvb_v1);
else
lvb = req_capsule_server_sized_swab_get(pill,
&RMF_DLM_LVB, lvb_len,
lustre_swab_ost_lvb_v1);
if (unlikely(lvb == NULL)) {
LDLM_ERROR(lock, "no LVB");
RETURN(-EPROTO);
}
memcpy(data, lvb, lvb_len);
olvb->lvb_mtime_ns = 0;
olvb->lvb_atime_ns = 0;
olvb->lvb_ctime_ns = 0;
} else {
LDLM_ERROR(lock, "Replied unexpected ost LVB size %d",
lvb_len);
RETURN(-EINVAL);
}
break;
case LVB_T_LQUOTA:
if (lvb_len == sizeof(struct lquota_lvb)) {
if (loc == RCL_CLIENT)
lvb = req_capsule_client_swab_get(pill,
&RMF_DLM_LVB,
lustre_swab_lquota_lvb);
else
lvb = req_capsule_server_swab_get(pill,
&RMF_DLM_LVB,
lustre_swab_lquota_lvb);
if (unlikely(lvb == NULL)) {
LDLM_ERROR(lock, "no LVB");
RETURN(-EPROTO);
}
memcpy(data, lvb, lvb_len);
} else {
LDLM_ERROR(lock,
"Replied unexpected lquota LVB size %d",
lvb_len);
RETURN(-EINVAL);
}
break;
case LVB_T_LAYOUT:
if (lvb_len == 0)
break;
if (loc == RCL_CLIENT)
lvb = req_capsule_client_get(pill, &RMF_DLM_LVB);
else
lvb = req_capsule_server_get(pill, &RMF_DLM_LVB);
if (unlikely(lvb == NULL)) {
LDLM_ERROR(lock, "no LVB");
RETURN(-EPROTO);
}
memcpy(data, lvb, lvb_len);
break;
default:
LDLM_ERROR(lock, "Unknown LVB type=%d, size=%d",
lock->l_lvb_type, lvb_len);
dump_stack();
RETURN(-EINVAL);
}
RETURN(0);
}
/* Create and fill in new LDLM lock with specified properties.
* Returns: a referenced lock
*/
struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
const struct ldlm_res_id *res_id,
enum ldlm_type type,
enum ldlm_mode mode,
const struct ldlm_callback_suite *cbs,
void *data, __u32 lvb_len,
enum lvb_type lvb_type)
{
struct ldlm_lock *lock;
struct ldlm_resource *res;
int rc = 0;
ENTRY;
res = ldlm_resource_get(ns, res_id, type, 1);
if (IS_ERR(res))
RETURN(ERR_CAST(res));
lock = ldlm_lock_new(res);
if (!lock) {
ldlm_resource_putref(res);
RETURN(ERR_PTR(-ENOMEM));
}
lock->l_req_mode = mode;
lock->l_ast_data = data;
lock->l_pid = current->pid;
if (ns_is_server(ns))
(lock->l_flags |= LDLM_FL_NS_SRV);
if (cbs) {
lock->l_blocking_ast = cbs->lcs_blocking;
lock->l_completion_ast = cbs->lcs_completion;
lock->l_glimpse_ast = cbs->lcs_glimpse;
}
if (type == LDLM_IBITS) {
rc = ldlm_inodebits_alloc_lock(lock);
if (rc)
GOTO(out, rc);
}
if (lvb_len) {
LASSERT(lvb_len < 1 << sizeof(lock->l_lvb_len) * 8);
lock->l_lvb_len = lvb_len;
OBD_ALLOC_LARGE(lock->l_lvb_data, lvb_len);
if (lock->l_lvb_data == NULL)
GOTO(out, rc = -ENOMEM);
}
lock->l_lvb_type = lvb_type;
if (CFS_FAIL_CHECK(OBD_FAIL_LDLM_NEW_LOCK))
GOTO(out, rc = -ENOENT);
RETURN(lock);
out:
ldlm_lock_destroy(lock);
ldlm_lock_put(lock);
RETURN(ERR_PTR(rc));
}
#ifdef CONFIG_LUSTRE_FS_SERVER
static enum ldlm_error ldlm_lock_enqueue_helper(struct ldlm_lock *lock,
__u64 *flags)
{
struct ldlm_resource *res = lock->l_resource;
enum ldlm_error rc = ELDLM_OK;
LIST_HEAD(rpc_list);
ldlm_processing_policy policy;
ENTRY;
policy = ldlm_get_processing_policy(res);
policy(lock, flags, LDLM_PROCESS_ENQUEUE, &rc, &rpc_list);
if (rc == ELDLM_OK && lock->l_granted_mode != lock->l_req_mode &&
res->lr_type != LDLM_FLOCK)
rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list);
if (!list_empty(&rpc_list))
ldlm_discard_bl_list(&rpc_list);
RETURN(rc);
}
#endif
/**
* Enqueue (request) a lock.
*
* Does not block. As a result of enqueue the lock would be put
* into granted or waiting list.
*
* If namespace has intent policy sent and the lock has LDLM_FL_HAS_INTENT flag
* set, skip all the enqueueing and delegate lock processing to intent policy
* function.
*/
enum ldlm_error ldlm_lock_enqueue(const struct lu_env *env,
struct ldlm_namespace *ns,
struct ldlm_lock **lockp,
void *cookie, __u64 *flags)
{
struct ldlm_lock *lock = *lockp;
struct ldlm_resource *res;
int local = ns_is_client(ns);
enum ldlm_error rc = ELDLM_OK;
#ifdef CONFIG_LUSTRE_FS_SERVER
bool reconstruct = false;
#endif
ENTRY;
/* policies are not executed on the client or during replay */
if ((*flags & (LDLM_FL_HAS_INTENT|LDLM_FL_REPLAY)) == LDLM_FL_HAS_INTENT
&& !local && ns->ns_policy) {
rc = ns->ns_policy(env, ns, lockp, cookie, lock->l_req_mode,
*flags, NULL);
if (rc == ELDLM_LOCK_REPLACED) {
/* The lock that was returned has already been granted,
* and placed into lockp. If it's not the same as the
* one we passed in, then destroy the old one and our
* work here is done.
*/
if (lock != *lockp) {
ldlm_lock_destroy(lock);
ldlm_lock_put(lock);
}
*flags |= LDLM_FL_LOCK_CHANGED;
RETURN(0);
} else if (rc != ELDLM_OK &&
ldlm_is_granted(lock)) {
LASSERT(*flags & LDLM_FL_RESENT);
/* It may happen that ns_policy returns an error in
* resend case, object may be unlinked or just some
* error occurs. It is unclear if lock reached the
* client in the original reply, just leave the lock on
* server, not returning it again to client. Due to
* LU-6529, the server will not OOM.
*/
RETURN(rc);
} else if (rc != ELDLM_OK ||
(rc == ELDLM_OK && (*flags & LDLM_FL_INTENT_ONLY))) {
ldlm_lock_destroy(lock);
RETURN(rc);
}
}
if (*flags & LDLM_FL_RESENT) {
/* Reconstruct LDLM_FL_SRV_ENQ_MASK @flags for reply.
* Set LOCK_CHANGED always.
* Check if the lock is granted for BLOCK_GRANTED.
* Take NO_TIMEOUT from the lock as it is inherited through
* LDLM_FL_INHERIT_MASK
*/
*flags |= LDLM_FL_LOCK_CHANGED;
if (!ldlm_is_granted(lock))
*flags |= LDLM_FL_BLOCK_GRANTED;
*flags |= lock->l_flags & LDLM_FL_NO_TIMEOUT;
RETURN(ELDLM_OK);
}
#ifdef CONFIG_LUSTRE_FS_SERVER
reconstruct = !local && lock->l_resource->lr_type == LDLM_FLOCK &&
!(*flags & LDLM_FL_TEST_LOCK);
if (reconstruct) {
rc = req_can_reconstruct(cookie, NULL);
if (rc != 0) {
if (rc == 1)
rc = 0;
RETURN(rc);
}
}
if (!local && lock->l_resource->lr_type == LDLM_FLOCK) {
struct ldlm_flock_node *fn = &lock->l_resource->lr_flock_node;
if (lock->l_req_mode == LCK_NL) {
atomic_inc(&fn->lfn_unlock_pending);
res = lock_res_and_lock(lock);
atomic_dec(&fn->lfn_unlock_pending);
} else {
res = lock_res_and_lock(lock);
while (atomic_read(&fn->lfn_unlock_pending)) {
unlock_res_and_lock(lock);
cond_resched();
lock_res_and_lock(lock);
}
}
} else
#endif
{
res = lock_res_and_lock(lock);
}
if (local && ldlm_is_granted(lock)) {
/* The server returned a blocked lock, but it was granted
* before we got a chance to actually enqueue it. We don't
* need to do anything else.
*/
*flags &= ~LDLM_FL_BLOCKED_MASK;
GOTO(out, rc = ELDLM_OK);
}
ldlm_resource_unlink_lock(lock);
/* Some flags from the enqueue want to make it into the AST, via the
* lock's l_flags.
*/
if (*flags & LDLM_FL_AST_DISCARD_DATA)
(lock->l_flags |= LDLM_FL_AST_DISCARD_DATA);
if (*flags & LDLM_FL_TEST_LOCK)
(lock->l_flags |= LDLM_FL_TEST_LOCK);
/* This distinction between local lock trees is very important; a client
* namespace only has information about locks taken by that client, and
* thus doesn't have enough information to decide for itself if it can
* be granted (below). In this case, we do exactly what the server
* tells us to do, as dictated by the 'flags'.
*
* We do exactly the same thing during recovery, when the server is
* more or less trusting the clients not to lie.
*
* FIXME (bug 268): Detect obvious lies by checking compatibility in
* granted queue.
*/
if (local) {
if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
ldlm_resource_add_lock(res, &res->lr_waiting, lock);
else
ldlm_grant_lock(lock, NULL);
GOTO(out, rc = ELDLM_OK);
#ifdef CONFIG_LUSTRE_FS_SERVER
} else if (*flags & LDLM_FL_REPLAY) {
if (*flags & LDLM_FL_BLOCK_WAIT) {
ldlm_resource_add_lock(res, &res->lr_waiting, lock);
GOTO(out, rc = ELDLM_OK);
} else if (*flags & LDLM_FL_BLOCK_GRANTED) {
ldlm_grant_lock(lock, NULL);
GOTO(out, rc = ELDLM_OK);
}
/* If no flags, fall through to normal enqueue path. */
}
rc = ldlm_lock_enqueue_helper(lock, flags);
GOTO(out, rc);
#else
} else {
CERROR("This is client-side-only module, cannot handle LDLM_NAMESPACE_SERVER resource type lock.\n");
LBUG();
}
#endif
out:
unlock_res_and_lock(lock);
#ifdef CONFIG_LUSTRE_FS_SERVER
if (reconstruct) {
struct ptlrpc_request *req = cookie;
tgt_mk_reply_data(NULL, NULL,
&req->rq_export->exp_target_data,
req, 0, NULL, false, 0);
}
#endif
return rc;
}
#ifdef CONFIG_LUSTRE_FS_SERVER
/**
* Iterate through all waiting locks on a given resource queue and attempt to
* grant them.
*
* Must be called with resource lock held.
*/
int ldlm_reprocess_queue(struct ldlm_resource *res, struct list_head *queue,
struct list_head *work_list,
enum ldlm_process_intention intention,
enum mds_ibits_locks hint)
{
struct list_head *tmp, *pos;
ldlm_processing_policy policy;
__u64 flags;
int rc = LDLM_ITER_CONTINUE;
enum ldlm_error err;
LIST_HEAD(bl_ast_list);
ENTRY;
check_res_locked(res);
policy = ldlm_get_processing_policy(res);
LASSERT(policy);
LASSERT(intention == LDLM_PROCESS_RESCAN ||
intention == LDLM_PROCESS_RECOVERY);
restart:
list_for_each_safe(tmp, pos, queue) {
struct ldlm_lock *pending;
LIST_HEAD(rpc_list);
pending = list_entry(tmp, struct ldlm_lock, l_res_link);
CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
flags = 0;
rc = policy(pending, &flags, intention, &err, &rpc_list);
if (pending->l_granted_mode == pending->l_req_mode ||
res->lr_type == LDLM_FLOCK) {
list_splice(&rpc_list, work_list);
} else {
list_splice(&rpc_list, &bl_ast_list);
}
/*
* When this is called from recovery done, we always want
* to scan the whole list no matter what 'rc' is returned.
*/
if (rc != LDLM_ITER_CONTINUE &&
intention == LDLM_PROCESS_RESCAN)
break;
}
if (!list_empty(&bl_ast_list)) {
unlock_res(res);
rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &bl_ast_list,
LDLM_WORK_BL_AST);
lock_res(res);
if (rc == -ERESTART)
GOTO(restart, rc);
}
if (!list_empty(&bl_ast_list))
ldlm_discard_bl_list(&bl_ast_list);
RETURN(intention == LDLM_PROCESS_RESCAN ? rc : LDLM_ITER_CONTINUE);
}
/**
* Conflicting locks are detected for a lock to be enqueued, add the lock
* into waiting list and send blocking ASTs to the conflicting locks.
*
* \param[in] lock The lock to be enqueued.
* \param[out] flags Lock flags for the lock to be enqueued.
* \param[in] rpc_list Conflicting locks list.
*
* \retval -ERESTART: Some lock was instantly canceled while sending
* blocking ASTs, caller needs to re-check conflicting
* locks.
* \retval -EAGAIN: Lock was destroyed, caller should return error.
* \reval 0: Lock is successfully added in waiting list.
*/
int ldlm_handle_conflict_lock(struct ldlm_lock *lock, __u64 *flags,
struct list_head *rpc_list)
{
struct ldlm_resource *res = lock->l_resource;
int rc;
ENTRY;
check_res_locked(res);
/* If either of the compat_queue()s returned failure, then we
* have ASTs to send and must go onto the waiting list.
*
* bug 2322: we used to unlink and re-add here, which was a
* terrible folly -- if we goto restart, we could get
* re-ordered! Causes deadlock, because ASTs aren't sent!
*/
if (list_empty(&lock->l_res_link))
ldlm_resource_add_lock(res, &res->lr_waiting, lock);
unlock_res(res);
rc = ldlm_run_ast_work(ldlm_res_to_ns(res), rpc_list,
LDLM_WORK_BL_AST);
if (CFS_FAIL_CHECK(OBD_FAIL_LDLM_OST_FAIL_RACE) &&
!ns_is_client(ldlm_res_to_ns(res)))
class_fail_export(lock->l_export);
if (rc == -ERESTART)
ldlm_reprocess_all(res, 0);
lock_res(res);
if (rc == -ERESTART) {
/* 15715: The lock was granted and destroyed after
* resource lock was dropped. Interval node was freed
* in ldlm_lock_destroy. Anyway, this always happens
* when a client is being evicted. So it would be
* ok to return an error. -jay
*/
if ((lock->l_flags & LDLM_FL_DESTROYED))
RETURN(-EAGAIN);
/* lock was granted while resource was unlocked. */
if (ldlm_is_granted(lock)) {
/* bug 11300: if the lock has been granted,
* break earlier because otherwise, we will go
* to restart and ldlm_resource_unlink will be
* called and it causes the interval node to be
* freed. Then we will fail at
* ldlm_extent_add_lock()
*/
*flags &= ~LDLM_FL_BLOCKED_MASK;
}
}
*flags |= LDLM_FL_BLOCK_GRANTED;
RETURN(0);
}
/**
* Discard all AST work items from list.
*
* If for whatever reason we do not want to send ASTs to conflicting locks
* anymore, disassemble the list with this function.
*/
void ldlm_discard_bl_list(struct list_head *bl_list)
{
struct ldlm_lock *lock, *tmp;
ENTRY;
list_for_each_entry_safe(lock, tmp, bl_list, l_bl_ast) {
LASSERT(!list_empty(&lock->l_bl_ast));
list_del_init(&lock->l_bl_ast);
(lock->l_flags &= ~LDLM_FL_AST_SENT);
LASSERT(lock->l_bl_ast_run == 0);
ldlm_clear_blocking_lock(lock);
ldlm_lock_put(lock);
}
EXIT;
}
/* Process a call to blocking AST callback for a lock in ast_work list */
static int
ldlm_work_bl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
{
struct ldlm_cb_set_arg *arg = opaq;
struct ldlm_lock *lock;
struct ldlm_lock_desc d;
struct ldlm_bl_desc bld;
int rc;
ENTRY;
if (list_empty(arg->list))
RETURN(-ENOENT);
lock = list_first_entry(arg->list, struct ldlm_lock, l_bl_ast);
/* nobody should touch l_bl_ast but some locks in the list may become
* granted after lock convert or COS downgrade, these locks should be
* just skipped here and removed from the list.
*/
lock_res_and_lock(lock);
list_del_init(&lock->l_bl_ast);
/* lock is not blocking lock anymore, but was kept in the list because
* it can managed only here.
*/
if (!(lock->l_flags & LDLM_FL_AST_SENT)) {
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
RETURN(0);
}
LASSERT(lock->l_blocking_lock);
ldlm_lock2desc(lock->l_blocking_lock, &d);
/* copy blocking lock ibits in cancel_bits as well,
* new client may use them for lock convert and it is
* important to use new field to convert locks from
* new servers only
*/
d.l_policy_data.l_inodebits.cancel_bits =
lock->l_blocking_lock->l_policy_data.l_inodebits.bits;
/* Blocking lock is being destroyed here but some information about it
* may be needed inside l_blocking_ast() function below,
* e.g. in mdt_blocking_ast(). So save needed data in bl_desc.
*/
bld.bl_same_client = lock->l_client_cookie ==
lock->l_blocking_lock->l_client_cookie;
/* if two locks are initiated from the same MDT, transactions are
* independent, or the request lock mode isn't EX|PW, no need to trigger
* CoS because current lock will be downgraded to TXN mode soon, then
* the blocking lock can be granted.
*/
if (lock->l_blocking_lock->l_policy_data.l_inodebits.li_initiator_id ==
lock->l_policy_data.l_inodebits.li_initiator_id ||
!(lock->l_blocking_lock->l_req_mode & (LCK_EX | LCK_PW)))
bld.bl_txn_dependent = false;
else
bld.bl_txn_dependent = true;
arg->bl_desc = &bld;
LASSERT(lock->l_flags & LDLM_FL_AST_SENT);
LASSERT(lock->l_bl_ast_run == 0);
lock->l_bl_ast_run = 1;
ldlm_clear_blocking_lock(lock);
unlock_res_and_lock(lock);
rc = lock->l_blocking_ast(lock, &d, (void *)arg, LDLM_CB_BLOCKING);
ldlm_lock_put(lock);
RETURN(rc);
}
/* Process a call to revocation AST callback for a lock in ast_work list */
static int
ldlm_work_revoke_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
{
struct ldlm_cb_set_arg *arg = opaq;
struct ldlm_lock_desc desc;
int rc;
struct ldlm_lock *lock;
ENTRY;
if (list_empty(arg->list))
RETURN(-ENOENT);
lock = list_first_entry(arg->list, struct ldlm_lock, l_rk_ast);
list_del_init(&lock->l_rk_ast);
/* the desc just pretend to exclusive */
ldlm_lock2desc(lock, &desc);
desc.l_req_mode = LCK_EX;
desc.l_granted_mode = 0;
rc = lock->l_blocking_ast(lock, &desc, (void *)arg, LDLM_CB_BLOCKING);
ldlm_lock_put(lock);
RETURN(rc);
}
/* Process a call to glimpse AST callback for a lock in ast_work list */
int ldlm_work_gl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
{
struct ldlm_cb_set_arg *arg = opaq;
struct ldlm_glimpse_work *gl_work;
struct ldlm_lock *lock;
int rc = 0;
ENTRY;
if (list_empty(arg->list))
RETURN(-ENOENT);
gl_work = list_first_entry(arg->list, struct ldlm_glimpse_work,
gl_list);
list_del_init(&gl_work->gl_list);
lock = gl_work->gl_lock;
/* transfer the glimpse descriptor to ldlm_cb_set_arg */
arg->gl_desc = gl_work->gl_desc;
arg->gl_interpret_reply = gl_work->gl_interpret_reply;
arg->gl_interpret_data = gl_work->gl_interpret_data;
/* invoke the actual glimpse callback */
rc = lock->l_glimpse_ast(lock, (void *)arg);
if (rc == 0)
rc = 1; /* update LVB if this is server lock */
else if (rc == -ELDLM_NO_LOCK_DATA)
ldlm_lvbo_update(lock->l_resource, lock, NULL, 1);
ldlm_lock_put(lock);
if (gl_work->gl_flags & LDLM_GL_WORK_SLAB_ALLOCATED)
OBD_SLAB_FREE_PTR(gl_work, ldlm_glimpse_work_kmem);
else
OBD_FREE_PTR(gl_work);
RETURN(rc);
}
#endif
/* Process a call to completion AST callback for a lock in ast_work list */
static int
ldlm_work_cp_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
{
struct ldlm_cb_set_arg *arg = opaq;
struct ldlm_lock *lock;
ldlm_completion_callback completion_callback;
int rc = 0;
ENTRY;
if (list_empty(arg->list))
RETURN(-ENOENT);
lock = list_first_entry(arg->list, struct ldlm_lock, l_cp_ast);
/* It's possible to receive a completion AST before we've set
* the l_completion_ast pointer: either because the AST arrived
* before the reply, or simply because there's a small race
* window between receiving the reply and finishing the local
* enqueue. (bug 842)
*
* This can't happen with the blocking_ast, however, because we
* will never call the local blocking_ast until we drop our
* reader/writer reference, which we won't do until we get the
* reply and finish enqueueing.
*/
/* nobody should touch l_cp_ast */
lock_res_and_lock(lock);
list_del_init(&lock->l_cp_ast);
LASSERT(lock->l_flags & LDLM_FL_CP_REQD);
/* save l_completion_ast since it can be changed by
* mds_intent_policy(), see bug 14225
*/
completion_callback = lock->l_completion_ast;
lock->l_flags &= ~LDLM_FL_CP_REQD;
unlock_res_and_lock(lock);
if (completion_callback != NULL)
rc = completion_callback(lock, 0, (void *)arg);
ldlm_lock_put(lock);
RETURN(rc);
}
/**
* Process list of locks in need of ASTs being sent.
*
* Used on server to send multiple ASTs together instead of sending one by
* one.
*/
int ldlm_run_ast_work(struct ldlm_namespace *ns, struct list_head *rpc_list,
ldlm_desc_ast_t ast_type)
{
struct ldlm_cb_set_arg *arg;
set_producer_func work_ast_lock;
int rc;
if (list_empty(rpc_list))
RETURN(0);
OBD_ALLOC_PTR(arg);
if (arg == NULL)
RETURN(-ENOMEM);
atomic_set(&arg->restart, 0);
arg->list = rpc_list;
switch (ast_type) {
case LDLM_WORK_CP_AST:
arg->type = LDLM_CP_CALLBACK;
work_ast_lock = ldlm_work_cp_ast_lock;
break;
#ifdef CONFIG_LUSTRE_FS_SERVER
case LDLM_WORK_BL_AST:
arg->type = LDLM_BL_CALLBACK;
work_ast_lock = ldlm_work_bl_ast_lock;
break;
case LDLM_WORK_REVOKE_AST:
arg->type = LDLM_BL_CALLBACK;
work_ast_lock = ldlm_work_revoke_ast_lock;
break;
case LDLM_WORK_GL_AST:
arg->type = LDLM_GL_CALLBACK;
work_ast_lock = ldlm_work_gl_ast_lock;
break;
#endif
default:
LBUG();
}
/* We create a ptlrpc request set with flow control extension.
* This request set will use the work_ast_lock function to produce new
* requests and will send a new request each time one completes in order
* to keep the number of requests in flight to ns_max_parallel_ast
*/
arg->set = ptlrpc_prep_fcset(ns->ns_max_parallel_ast ? : UINT_MAX,
work_ast_lock, arg);
if (arg->set == NULL)
GOTO(out, rc = -ENOMEM);
ptlrpc_set_wait(NULL, arg->set);
ptlrpc_set_destroy(arg->set);
rc = atomic_read(&arg->restart) ? -ERESTART : 0;
GOTO(out, rc);
out:
OBD_FREE_PTR(arg);
return rc;
}
/**
* Try to grant all waiting locks on a resource.
*
* Calls ldlm_reprocess_queue on waiting queue.
*
* Typically called after some resource locks are cancelled to see
* if anything could be granted as a result of the cancellation.
*/
static void __ldlm_reprocess_all(struct ldlm_resource *res,
enum ldlm_process_intention intention,
enum mds_ibits_locks hint)
{
LIST_HEAD(rpc_list);
#ifdef CONFIG_LUSTRE_FS_SERVER
ldlm_reprocessing_policy reprocess;
struct obd_device *obd;
int rc;
ENTRY;
/* Local lock trees don't get reprocessed. */
if (ns_is_client(ldlm_res_to_ns(res))) {
EXIT;
return;
}
/* Disable reprocess during lock replay stage but allow during
* request replay stage.
*/
obd = ldlm_res_to_ns(res)->ns_obd;
if (test_bit(OBDF_RECOVERING, obd->obd_flags) &&
atomic_read(&obd->obd_req_replay_clients) == 0)
RETURN_EXIT;
restart:
lock_res(res);
reprocess = ldlm_get_reprocessing_policy(res);
reprocess(res, &res->lr_waiting, &rpc_list, intention, hint);
unlock_res(res);
rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
LDLM_WORK_CP_AST);
if (rc == -ERESTART) {
LASSERT(list_empty(&rpc_list));
hint = 0;
goto restart;
}
#else
ENTRY;
LASSERTF(ns_is_client(ldlm_res_to_ns(res)),
"This is client-side-only module, cannot handle LDLM_NAMESPACE_SERVER resource type lock.\n");
#endif
EXIT;
}
void ldlm_reprocess_all(struct ldlm_resource *res, enum mds_ibits_locks hint)
{
__ldlm_reprocess_all(res, LDLM_PROCESS_RESCAN, hint);
}
EXPORT_SYMBOL(ldlm_reprocess_all);
static int ldlm_reprocess_res(struct cfs_hash *hs, struct cfs_hash_bd *bd,
struct hlist_node *hnode, void *arg)
{
struct ldlm_resource *res = cfs_hash_object(hs, hnode);
/* This is only called once after recovery done. LU-8306. */
__ldlm_reprocess_all(res, LDLM_PROCESS_RECOVERY, 0);
return 0;
}
/* Iterate on all resources on namespace attempting to grant waiting locks. */
void ldlm_reprocess_recovery_done(struct ldlm_namespace *ns)
{
ENTRY;
if (ns != NULL) {
cfs_hash_for_each_nolock(ns->ns_rs_hash,
ldlm_reprocess_res, NULL, 0);
}
EXIT;
}
/* Helper to call blocking AST for LDLM lock \a lock in a "cancelling" mode. */
void ldlm_cancel_callback(struct ldlm_lock *lock)
{
check_res_locked(lock->l_resource);
if (!(lock->l_flags & LDLM_FL_CANCEL)) {
(lock->l_flags |= LDLM_FL_CANCEL);
if (lock->l_blocking_ast) {
unlock_res_and_lock(lock);
lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
LDLM_CB_CANCELING);
lock_res_and_lock(lock);
} else {
LDLM_DEBUG(lock, "no blocking ast");
}
/* only canceller can set bl_done bit */
(lock->l_flags |= LDLM_FL_BL_DONE);
wake_up(&lock->l_waitq);
} else if (!(lock->l_flags & LDLM_FL_BL_DONE)) {
/* lock is guaranteed to be canceled returning from function. */
unlock_res_and_lock(lock);
wait_event_idle(lock->l_waitq, is_bl_done(lock));
lock_res_and_lock(lock);
}
}
/* Remove skiplist-enabled LDLM lock \a req from granted list */
void ldlm_unlink_lock_skiplist(struct ldlm_lock *req)
{
if (req->l_resource->lr_type != LDLM_PLAIN &&
req->l_resource->lr_type != LDLM_IBITS)
return;
list_del_init(&req->l_sl_policy);
list_del_init(&req->l_sl_mode);
}
/* Attempts to cancel LDLM lock \a lock that has no reader/writer references. */
void ldlm_lock_cancel(struct ldlm_lock *lock)
{
struct ldlm_resource *res;
struct ldlm_namespace *ns;
ENTRY;
lock_res_and_lock(lock);
res = lock->l_resource;
ns = ldlm_res_to_ns(res);
/* Please do not remove this LBUG without talking to me first. -phik */
if (lock->l_readers || lock->l_writers) {
LDLM_ERROR(lock, "lock still has references");
unlock_res_and_lock(lock);
LBUG();
}
if (lock->l_flags & LDLM_FL_WAITED)
ldlm_del_waiting_lock(lock);
/* Releases cancel callback. */
ldlm_cancel_callback(lock);
/* Yes, second time, just in case it was added again while we were
* running with no res lock in ldlm_cancel_callback
*/
if (lock->l_flags & LDLM_FL_WAITED)
ldlm_del_waiting_lock(lock);
ldlm_resource_unlink_lock(lock);
ldlm_lock_destroy_nolock(lock);
if (ldlm_is_granted(lock))
ldlm_pool_del(&ns->ns_pool, lock);
/* should not be called again for same lock(zero out l_granted_mode) */
lock->l_granted_mode = LCK_MODE_MIN;
unlock_res_and_lock(lock);
EXIT;
}
EXPORT_SYMBOL(ldlm_lock_cancel);
/* Set opaque data into the lock that only makes sense to upper layer. */
int ldlm_lock_set_data(const struct lustre_handle *lockh, void *data)
{
struct ldlm_lock *lock = ldlm_handle2lock(lockh);
int rc = -EINVAL;
ENTRY;
if (lock) {
if (lock->l_ast_data == NULL)
lock->l_ast_data = data;
if (lock->l_ast_data == data)
rc = 0;
ldlm_lock_put(lock);
}
RETURN(rc);
}
EXPORT_SYMBOL(ldlm_lock_set_data);
struct export_cl_data {
const struct lu_env *ecl_env;
struct obd_export *ecl_exp;
int ecl_loop;
};
static void ldlm_cancel_lock_for_export(struct obd_export *exp,
struct ldlm_lock *lock,
struct export_cl_data *ecl)
{
struct ldlm_resource *res;
res = ldlm_resource_getref(lock->l_resource);
ldlm_lvbo_update(res, lock, NULL, 1);
ldlm_lock_cancel(lock);
if (!test_bit(OBDF_STOPPING, exp->exp_obd->obd_flags))
ldlm_reprocess_all(res, lock->l_policy_data.l_inodebits.bits);
ldlm_resource_putref(res);
ecl->ecl_loop++;
if ((ecl->ecl_loop & -ecl->ecl_loop) == ecl->ecl_loop) {
CDEBUG(D_INFO, "Export %p, %d locks cancelled.\n",
exp, ecl->ecl_loop);
}
}
/**
* Iterator function for ldlm_export_cancel_locks.
* Cancels passed locks.
*/
static int
ldlm_cancel_locks_for_export_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
struct hlist_node *hnode, void *data)
{
struct export_cl_data *ecl = (struct export_cl_data *)data;
struct obd_export *exp = ecl->ecl_exp;
struct ldlm_lock *lock = cfs_hash_object(hs, hnode);
ldlm_lock_get(lock);
ldlm_cancel_lock_for_export(exp, lock, ecl);
ldlm_lock_put(lock);
return 0;
}
/**
* Cancel all blocked locks for given export.
*
* Typically called on client disconnection/eviction
*/
int ldlm_export_cancel_blocked_locks(struct obd_export *exp)
{
struct lu_env env;
struct export_cl_data ecl = {
.ecl_exp = exp,
.ecl_loop = 0,
};
int rc;
rc = lu_env_init(&env, LCT_DT_THREAD);
if (rc)
RETURN(rc);
ecl.ecl_env = &env;
while (!list_empty(&exp->exp_bl_list)) {
struct ldlm_lock *lock;
spin_lock_bh(&exp->exp_bl_list_lock);
if (!list_empty(&exp->exp_bl_list)) {
lock = list_first_entry(&exp->exp_bl_list,
struct ldlm_lock, l_exp_list);
ldlm_lock_get(lock);
list_del_init(&lock->l_exp_list);
} else {
lock = NULL;
}
spin_unlock_bh(&exp->exp_bl_list_lock);
if (lock == NULL)
break;
ldlm_cancel_lock_for_export(exp, lock, &ecl);
ldlm_lock_put(lock);
}
lu_env_fini(&env);
CDEBUG(D_DLMTRACE,
"Export %p, canceled %d locks, left on hash table %d.\n", exp,
ecl.ecl_loop, atomic_read(&exp->exp_lock_hash->hs_count));
return ecl.ecl_loop;
}
/**
* Cancel all locks for given export.
*
* Typically called after client disconnection/eviction
*/
int ldlm_export_cancel_locks(struct obd_export *exp)
{
struct export_cl_data ecl;
struct lu_env env;
int rc;
rc = lu_env_init(&env, LCT_DT_THREAD);
if (rc)
RETURN(rc);
ecl.ecl_env = &env;
ecl.ecl_exp = exp;
ecl.ecl_loop = 0;
cfs_hash_for_each_empty(exp->exp_lock_hash,
ldlm_cancel_locks_for_export_cb, &ecl);
CDEBUG(D_DLMTRACE,
"Export %p, canceled %d locks, left on hash table %d.\n", exp,
ecl.ecl_loop, atomic_read(&exp->exp_lock_hash->hs_count));
if (ecl.ecl_loop > 0 &&
atomic_read(&exp->exp_lock_hash->hs_count) == 0 &&
test_bit(OBDF_STOPPING, exp->exp_obd->obd_flags))
ldlm_reprocess_recovery_done(exp->exp_obd->obd_namespace);
lu_env_fini(&env);
return ecl.ecl_loop;
}
/**
* Downgrade an PW/EX lock to COS, TXN or CR mode.
*
* A lock mode convertion from PW/EX mode to less conflict mode. The
* convertion may fail if lock was canceled before downgrade, but it doesn't
* indicate any problem, because such lock has no reader or writer, and will
* be released soon.
*
* Used by Commit on Sharing (COS) code to force object changes commit in case
* of conflict. Converted lock is considered as new lock and all blocking AST
* things are cleared, so any pending or new blocked lock on that lock will
* cause new call to blocking_ast and force resource object commit.
*
* Used by DNE to force commit upon operation dependency.
*
* Also used by layout_change to replace EX lock to CR lock.
*
* \param lock A lock to convert
* \param new_mode new lock mode
*/
void ldlm_lock_mode_downgrade(struct ldlm_lock *lock, enum ldlm_mode new_mode)
{
#ifdef CONFIG_LUSTRE_FS_SERVER
ENTRY;
LASSERT(new_mode == LCK_COS || new_mode == LCK_TXN ||
new_mode == LCK_CR);
lock_res_and_lock(lock);
if (!(lock->l_granted_mode & (LCK_PW | LCK_EX))) {
unlock_res_and_lock(lock);
LASSERT(lock->l_granted_mode == LCK_MODE_MIN);
LDLM_DEBUG(lock, "lock was canceled before downgrade");
RETURN_EXIT;
}
ldlm_resource_unlink_lock(lock);
/*
* Remove the lock from pool as it will be added again in
* ldlm_grant_lock() called below.
*/
ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
/* Consider downgraded lock as a new lock and clear all states
* related to a previous blocking AST processing.
*/
ldlm_clear_blocking_data(lock);
lock->l_req_mode = new_mode;
ldlm_grant_lock(lock, NULL);
unlock_res_and_lock(lock);
ldlm_reprocess_all(lock->l_resource,
lock->l_policy_data.l_inodebits.bits);
EXIT;
#endif
}
EXPORT_SYMBOL(ldlm_lock_mode_downgrade);
/**
* Print lock with lock handle \a lockh description into debug log.
*
* Used when printing all locks on a resource for debug purposes.
*/
void ldlm_lock_dump_handle(int level, const struct lustre_handle *lockh)
{
struct ldlm_lock *lock;
if (!((libcfs_debug | D_ERROR) & level))
return;
lock = ldlm_handle2lock(lockh);
if (lock == NULL)
return;
LDLM_DEBUG_LIMIT(level, lock, "###");
ldlm_lock_put(lock);
}
EXPORT_SYMBOL(ldlm_lock_dump_handle);
/**
* Print lock information with custom message into debug log.
* Helper function.
*/
void _ldlm_lock_debug(struct ldlm_lock *lock,
struct libcfs_debug_msg_data *msgdata,
const char *fmt, ...)
{
va_list args;
struct obd_export *exp = lock->l_export;
struct ldlm_resource *resource = NULL;
struct va_format vaf;
char *nid = "local";
rcu_read_lock();
resource = rcu_dereference(lock->l_resource);
if (resource && !refcount_inc_not_zero(&resource->lr_refcount))
resource = NULL;
rcu_read_unlock();
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
if (exp && exp->exp_connection) {
nid = obd_export_nid2str(exp);
} else if (exp && exp->exp_obd != NULL) {
struct obd_import *imp = exp->exp_obd->u.cli.cl_import;
nid = obd_import_nid2str(imp);
}
if (resource == NULL) {
libcfs_debug_msg(msgdata,
"%pV ns: \?\? lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: \?\? rrc=\?\? type: \?\?\? flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
&vaf,
lock,
lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
lock->l_flags, nid,
lock->l_remote_handle.cookie,
exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
lock->l_pid, lock->l_callback_timestamp,
lock->l_lvb_type);
va_end(args);
return;
}
switch (resource->lr_type) {
case LDLM_EXTENT:
libcfs_debug_msg(msgdata,
"%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s [%llu->%llu] (req %llu->%llu) gid %llu flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d lru_score: %d lru_type: %d\n",
&vaf,
ldlm_lock_to_ns_name(lock), lock,
lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
PLDLMRES(resource),
refcount_read(&resource->lr_refcount),
ldlm_typename[resource->lr_type],
lock->l_policy_data.l_extent.start,
lock->l_policy_data.l_extent.end,
lock->l_req_extent.start, lock->l_req_extent.end,
lock->l_req_extent.gid,
lock->l_flags, nid,
lock->l_remote_handle.cookie,
exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
lock->l_pid, lock->l_callback_timestamp,
lock->l_lvb_type, lock->l_lru_score,
lock->l_lru_type);
break;
case LDLM_FLOCK:
libcfs_debug_msg(msgdata,
"%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s pid: %d [%llu->%llu] flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld\n",
&vaf,
ldlm_lock_to_ns_name(lock), lock,
lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
PLDLMRES(resource),
refcount_read(&resource->lr_refcount),
ldlm_typename[resource->lr_type],
lock->l_policy_data.l_flock.pid,
lock->l_policy_data.l_flock.start,
lock->l_policy_data.l_flock.end,
lock->l_flags, nid,
lock->l_remote_handle.cookie,
exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
lock->l_pid, lock->l_callback_timestamp);
break;
case LDLM_IBITS:
if (!lock->l_remote_handle.cookie)
libcfs_debug_msg(msgdata,
"%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " bits %#lx/%#lx rrc: %d type: %s flags: %#llx pid: %u initiator: MDT%d lru_score: %d lru_type: %d\n",
&vaf,
ldlm_lock_to_ns_name(lock),
lock, lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
PLDLMRES(resource),
lock->l_policy_data.l_inodebits.bits,
lock->l_policy_data.l_inodebits.try_bits,
refcount_read(&resource->lr_refcount),
ldlm_typename[resource->lr_type],
lock->l_flags, lock->l_pid,
lock->l_policy_data.l_inodebits.li_initiator_id,
lock->l_lru_score, lock->l_lru_type);
else
libcfs_debug_msg(msgdata,
"%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " bits %#lx/%#lx rrc: %d type: %s gid %llu flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d lru_score: %d lru_type: %d\n",
&vaf,
ldlm_lock_to_ns_name(lock),
lock, lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
PLDLMRES(resource),
lock->l_policy_data.l_inodebits.bits,
lock->l_policy_data.l_inodebits.try_bits,
refcount_read(&resource->lr_refcount),
ldlm_typename[resource->lr_type],
lock->l_policy_data.l_inodebits.li_gid,
lock->l_flags, nid,
lock->l_remote_handle.cookie,
exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
lock->l_pid, lock->l_callback_timestamp,
lock->l_lvb_type, lock->l_lru_score,
lock->l_lru_type);
break;
default:
libcfs_debug_msg(msgdata,
"%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d lru_score: %d lru_type: %d\n",
&vaf,
ldlm_lock_to_ns_name(lock),
lock, lock->l_handle.h_cookie,
refcount_read(&lock->l_handle.h_ref),
lock->l_readers, lock->l_writers,
ldlm_lockname[lock->l_granted_mode],
ldlm_lockname[lock->l_req_mode],
PLDLMRES(resource),
refcount_read(&resource->lr_refcount),
ldlm_typename[resource->lr_type],
lock->l_flags, nid,
lock->l_remote_handle.cookie,
exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
lock->l_pid, lock->l_callback_timestamp,
lock->l_lvb_type, lock->l_lru_score,
lock->l_lru_type);
break;
}
va_end(args);
ldlm_resource_putref(resource);
}
EXPORT_SYMBOL(_ldlm_lock_debug);
