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nest-open-source / nest-learning-thermostat / 5.7.1 / linux-imx-ul / refs/heads/master / . / drivers / staging / lustre / lustre / osc / osc_lock.c
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/*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see
* http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
* GPL HEADER END
*/
/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2012, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Lustre is a trademark of Sun Microsystems, Inc.
*
* Implementation of cl_lock for OSC layer.
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
*/
#define DEBUG_SUBSYSTEM S_OSC
#include "../../include/linux/libcfs/libcfs.h"
/* fid_build_reg_res_name() */
#include "../include/lustre_fid.h"
#include "osc_cl_internal.h"
/** \addtogroup osc
* @{
*/
#define _PAGEREF_MAGIC (-10000000)
/*****************************************************************************
*
* Type conversions.
*
*/
static const struct cl_lock_operations osc_lock_ops;
static const struct cl_lock_operations osc_lock_lockless_ops;
static void osc_lock_to_lockless(const struct lu_env *env,
struct osc_lock *ols, int force);
static int osc_lock_has_pages(struct osc_lock *olck);
int osc_lock_is_lockless(const struct osc_lock *olck)
{
return (olck->ols_cl.cls_ops == &osc_lock_lockless_ops);
}
/**
* Returns a weak pointer to the ldlm lock identified by a handle. Returned
* pointer cannot be dereferenced, as lock is not protected from concurrent
* reclaim. This function is a helper for osc_lock_invariant().
*/
static struct ldlm_lock *osc_handle_ptr(struct lustre_handle *handle)
{
struct ldlm_lock *lock;
lock = ldlm_handle2lock(handle);
if (lock != NULL)
LDLM_LOCK_PUT(lock);
return lock;
}
/**
* Invariant that has to be true all of the time.
*/
static int osc_lock_invariant(struct osc_lock *ols)
{
struct ldlm_lock *lock = osc_handle_ptr(&ols->ols_handle);
struct ldlm_lock *olock = ols->ols_lock;
int handle_used = lustre_handle_is_used(&ols->ols_handle);
if (ergo(osc_lock_is_lockless(ols),
ols->ols_locklessable && ols->ols_lock == NULL))
return 1;
/*
* If all the following "ergo"s are true, return 1, otherwise 0
*/
if (!ergo(olock != NULL, handle_used))
return 0;
if (!ergo(olock != NULL,
olock->l_handle.h_cookie == ols->ols_handle.cookie))
return 0;
if (!ergo(handle_used,
ergo(lock != NULL && olock != NULL, lock == olock) &&
ergo(lock == NULL, olock == NULL)))
return 0;
/*
* Check that ->ols_handle and ->ols_lock are consistent, but
* take into account that they are set at the different time.
*/
if (!ergo(ols->ols_state == OLS_CANCELLED,
olock == NULL && !handle_used))
return 0;
/*
* DLM lock is destroyed only after we have seen cancellation
* ast.
*/
if (!ergo(olock != NULL && ols->ols_state < OLS_CANCELLED,
((olock->l_flags & LDLM_FL_DESTROYED) == 0)))
return 0;
if (!ergo(ols->ols_state == OLS_GRANTED,
olock != NULL &&
olock->l_req_mode == olock->l_granted_mode &&
ols->ols_hold))
return 0;
return 1;
}
/*****************************************************************************
*
* Lock operations.
*
*/
/**
* Breaks a link between osc_lock and dlm_lock.
*/
static void osc_lock_detach(const struct lu_env *env, struct osc_lock *olck)
{
struct ldlm_lock *dlmlock;
spin_lock(&osc_ast_guard);
dlmlock = olck->ols_lock;
if (dlmlock == NULL) {
spin_unlock(&osc_ast_guard);
return;
}
olck->ols_lock = NULL;
/* wb(); --- for all who checks (ols->ols_lock != NULL) before
* call to osc_lock_detach() */
dlmlock->l_ast_data = NULL;
olck->ols_handle.cookie = 0ULL;
spin_unlock(&osc_ast_guard);
lock_res_and_lock(dlmlock);
if (dlmlock->l_granted_mode == dlmlock->l_req_mode) {
struct cl_object *obj = olck->ols_cl.cls_obj;
struct cl_attr *attr = &osc_env_info(env)->oti_attr;
__u64 old_kms;
cl_object_attr_lock(obj);
/* Must get the value under the lock to avoid possible races. */
old_kms = cl2osc(obj)->oo_oinfo->loi_kms;
/* Update the kms. Need to loop all granted locks.
* Not a problem for the client */
attr->cat_kms = ldlm_extent_shift_kms(dlmlock, old_kms);
cl_object_attr_set(env, obj, attr, CAT_KMS);
cl_object_attr_unlock(obj);
}
unlock_res_and_lock(dlmlock);
/* release a reference taken in osc_lock_upcall0(). */
LASSERT(olck->ols_has_ref);
lu_ref_del(&dlmlock->l_reference, "osc_lock", olck);
LDLM_LOCK_RELEASE(dlmlock);
olck->ols_has_ref = 0;
}
static int osc_lock_unhold(struct osc_lock *ols)
{
int result = 0;
if (ols->ols_hold) {
ols->ols_hold = 0;
result = osc_cancel_base(&ols->ols_handle,
ols->ols_einfo.ei_mode);
}
return result;
}
static int osc_lock_unuse(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
switch (ols->ols_state) {
case OLS_NEW:
LASSERT(!ols->ols_hold);
LASSERT(ols->ols_agl);
return 0;
case OLS_UPCALL_RECEIVED:
osc_lock_unhold(ols);
case OLS_ENQUEUED:
LASSERT(!ols->ols_hold);
osc_lock_detach(env, ols);
ols->ols_state = OLS_NEW;
return 0;
case OLS_GRANTED:
LASSERT(!ols->ols_glimpse);
LASSERT(ols->ols_hold);
/*
* Move lock into OLS_RELEASED state before calling
* osc_cancel_base() so that possible synchronous cancellation
* (that always happens e.g., for liblustre) sees that lock is
* released.
*/
ols->ols_state = OLS_RELEASED;
return osc_lock_unhold(ols);
default:
CERROR("Impossible state: %d\n", ols->ols_state);
LBUG();
}
}
static void osc_lock_fini(const struct lu_env *env,
struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
/*
* ->ols_hold can still be true at this point if, for example, a
* thread that requested a lock was killed (and released a reference
* to the lock), before reply from a server was received. In this case
* lock is destroyed immediately after upcall.
*/
osc_lock_unhold(ols);
LASSERT(ols->ols_lock == NULL);
LASSERT(atomic_read(&ols->ols_pageref) == 0 ||
atomic_read(&ols->ols_pageref) == _PAGEREF_MAGIC);
OBD_SLAB_FREE_PTR(ols, osc_lock_kmem);
}
static void osc_lock_build_policy(const struct lu_env *env,
const struct cl_lock *lock,
ldlm_policy_data_t *policy)
{
const struct cl_lock_descr *d = &lock->cll_descr;
osc_index2policy(policy, d->cld_obj, d->cld_start, d->cld_end);
policy->l_extent.gid = d->cld_gid;
}
static __u64 osc_enq2ldlm_flags(__u32 enqflags)
{
__u64 result = 0;
LASSERT((enqflags & ~CEF_MASK) == 0);
if (enqflags & CEF_NONBLOCK)
result |= LDLM_FL_BLOCK_NOWAIT;
if (enqflags & CEF_ASYNC)
result |= LDLM_FL_HAS_INTENT;
if (enqflags & CEF_DISCARD_DATA)
result |= LDLM_FL_AST_DISCARD_DATA;
return result;
}
/**
* Global spin-lock protecting consistency of ldlm_lock::l_ast_data
* pointers. Initialized in osc_init().
*/
spinlock_t osc_ast_guard;
static struct osc_lock *osc_ast_data_get(struct ldlm_lock *dlm_lock)
{
struct osc_lock *olck;
lock_res_and_lock(dlm_lock);
spin_lock(&osc_ast_guard);
olck = dlm_lock->l_ast_data;
if (olck != NULL) {
struct cl_lock *lock = olck->ols_cl.cls_lock;
/*
* If osc_lock holds a reference on ldlm lock, return it even
* when cl_lock is in CLS_FREEING state. This way
*
* osc_ast_data_get(dlmlock) == NULL
*
* guarantees that all osc references on dlmlock were
* released. osc_dlm_blocking_ast0() relies on that.
*/
if (lock->cll_state < CLS_FREEING || olck->ols_has_ref) {
cl_lock_get_trust(lock);
lu_ref_add_atomic(&lock->cll_reference,
"ast", current);
} else
olck = NULL;
}
spin_unlock(&osc_ast_guard);
unlock_res_and_lock(dlm_lock);
return olck;
}
static void osc_ast_data_put(const struct lu_env *env, struct osc_lock *olck)
{
struct cl_lock *lock;
lock = olck->ols_cl.cls_lock;
lu_ref_del(&lock->cll_reference, "ast", current);
cl_lock_put(env, lock);
}
/**
* Updates object attributes from a lock value block (lvb) received together
* with the DLM lock reply from the server. Copy of osc_update_enqueue()
* logic.
*
* This can be optimized to not update attributes when lock is a result of a
* local match.
*
* Called under lock and resource spin-locks.
*/
static void osc_lock_lvb_update(const struct lu_env *env, struct osc_lock *olck,
int rc)
{
struct ost_lvb *lvb;
struct cl_object *obj;
struct lov_oinfo *oinfo;
struct cl_attr *attr;
unsigned valid;
if (!(olck->ols_flags & LDLM_FL_LVB_READY))
return;
lvb = &olck->ols_lvb;
obj = olck->ols_cl.cls_obj;
oinfo = cl2osc(obj)->oo_oinfo;
attr = &osc_env_info(env)->oti_attr;
valid = CAT_BLOCKS | CAT_ATIME | CAT_CTIME | CAT_MTIME | CAT_SIZE;
cl_lvb2attr(attr, lvb);
cl_object_attr_lock(obj);
if (rc == 0) {
struct ldlm_lock *dlmlock;
__u64 size;
dlmlock = olck->ols_lock;
LASSERT(dlmlock != NULL);
/* re-grab LVB from a dlm lock under DLM spin-locks. */
*lvb = *(struct ost_lvb *)dlmlock->l_lvb_data;
size = lvb->lvb_size;
/* Extend KMS up to the end of this lock and no further
* A lock on [x,y] means a KMS of up to y + 1 bytes! */
if (size > dlmlock->l_policy_data.l_extent.end)
size = dlmlock->l_policy_data.l_extent.end + 1;
if (size >= oinfo->loi_kms) {
LDLM_DEBUG(dlmlock, "lock acquired, setting rss=%llu, kms=%llu",
lvb->lvb_size, size);
valid |= CAT_KMS;
attr->cat_kms = size;
} else {
LDLM_DEBUG(dlmlock, "lock acquired, setting rss=%llu; leaving kms=%llu, end=%llu",
lvb->lvb_size, oinfo->loi_kms,
dlmlock->l_policy_data.l_extent.end);
}
ldlm_lock_allow_match_locked(dlmlock);
} else if (rc == -ENAVAIL && olck->ols_glimpse) {
CDEBUG(D_INODE, "glimpsed, setting rss=%llu; leaving kms=%llu\n",
lvb->lvb_size, oinfo->loi_kms);
} else
valid = 0;
if (valid != 0)
cl_object_attr_set(env, obj, attr, valid);
cl_object_attr_unlock(obj);
}
/**
* Called when a lock is granted, from an upcall (when server returned a
* granted lock), or from completion AST, when server returned a blocked lock.
*
* Called under lock and resource spin-locks, that are released temporarily
* here.
*/
static void osc_lock_granted(const struct lu_env *env, struct osc_lock *olck,
struct ldlm_lock *dlmlock, int rc)
{
struct ldlm_extent *ext;
struct cl_lock *lock;
struct cl_lock_descr *descr;
LASSERT(dlmlock->l_granted_mode == dlmlock->l_req_mode);
if (olck->ols_state < OLS_GRANTED) {
lock = olck->ols_cl.cls_lock;
ext = &dlmlock->l_policy_data.l_extent;
descr = &osc_env_info(env)->oti_descr;
descr->cld_obj = lock->cll_descr.cld_obj;
/* XXX check that ->l_granted_mode is valid. */
descr->cld_mode = osc_ldlm2cl_lock(dlmlock->l_granted_mode);
descr->cld_start = cl_index(descr->cld_obj, ext->start);
descr->cld_end = cl_index(descr->cld_obj, ext->end);
descr->cld_gid = ext->gid;
/*
* tell upper layers the extent of the lock that was actually
* granted
*/
olck->ols_state = OLS_GRANTED;
osc_lock_lvb_update(env, olck, rc);
/* release DLM spin-locks to allow cl_lock_{modify,signal}()
* to take a semaphore on a parent lock. This is safe, because
* spin-locks are needed to protect consistency of
* dlmlock->l_*_mode and LVB, and we have finished processing
* them. */
unlock_res_and_lock(dlmlock);
cl_lock_modify(env, lock, descr);
cl_lock_signal(env, lock);
LINVRNT(osc_lock_invariant(olck));
lock_res_and_lock(dlmlock);
}
}
static void osc_lock_upcall0(const struct lu_env *env, struct osc_lock *olck)
{
struct ldlm_lock *dlmlock;
dlmlock = ldlm_handle2lock_long(&olck->ols_handle, 0);
LASSERT(dlmlock != NULL);
lock_res_and_lock(dlmlock);
spin_lock(&osc_ast_guard);
LASSERT(dlmlock->l_ast_data == olck);
LASSERT(olck->ols_lock == NULL);
olck->ols_lock = dlmlock;
spin_unlock(&osc_ast_guard);
/*
* Lock might be not yet granted. In this case, completion ast
* (osc_ldlm_completion_ast()) comes later and finishes lock
* granting.
*/
if (dlmlock->l_granted_mode == dlmlock->l_req_mode)
osc_lock_granted(env, olck, dlmlock, 0);
unlock_res_and_lock(dlmlock);
/*
* osc_enqueue_interpret() decrefs asynchronous locks, counter
* this.
*/
ldlm_lock_addref(&olck->ols_handle, olck->ols_einfo.ei_mode);
olck->ols_hold = 1;
/* lock reference taken by ldlm_handle2lock_long() is owned by
* osc_lock and released in osc_lock_detach() */
lu_ref_add(&dlmlock->l_reference, "osc_lock", olck);
olck->ols_has_ref = 1;
}
/**
* Lock upcall function that is executed either when a reply to ENQUEUE rpc is
* received from a server, or after osc_enqueue_base() matched a local DLM
* lock.
*/
static int osc_lock_upcall(void *cookie, int errcode)
{
struct osc_lock *olck = cookie;
struct cl_lock_slice *slice = &olck->ols_cl;
struct cl_lock *lock = slice->cls_lock;
struct lu_env *env;
struct cl_env_nest nest;
env = cl_env_nested_get(&nest);
if (!IS_ERR(env)) {
int rc;
cl_lock_mutex_get(env, lock);
LASSERT(lock->cll_state >= CLS_QUEUING);
if (olck->ols_state == OLS_ENQUEUED) {
olck->ols_state = OLS_UPCALL_RECEIVED;
rc = ldlm_error2errno(errcode);
} else if (olck->ols_state == OLS_CANCELLED) {
rc = -EIO;
} else {
CERROR("Impossible state: %d\n", olck->ols_state);
LBUG();
}
if (rc) {
struct ldlm_lock *dlmlock;
dlmlock = ldlm_handle2lock(&olck->ols_handle);
if (dlmlock != NULL) {
lock_res_and_lock(dlmlock);
spin_lock(&osc_ast_guard);
LASSERT(olck->ols_lock == NULL);
dlmlock->l_ast_data = NULL;
olck->ols_handle.cookie = 0ULL;
spin_unlock(&osc_ast_guard);
ldlm_lock_fail_match_locked(dlmlock);
unlock_res_and_lock(dlmlock);
LDLM_LOCK_PUT(dlmlock);
}
} else {
if (olck->ols_glimpse)
olck->ols_glimpse = 0;
osc_lock_upcall0(env, olck);
}
/* Error handling, some errors are tolerable. */
if (olck->ols_locklessable && rc == -EUSERS) {
/* This is a tolerable error, turn this lock into
* lockless lock.
*/
osc_object_set_contended(cl2osc(slice->cls_obj));
LASSERT(slice->cls_ops == &osc_lock_ops);
/* Change this lock to ldlmlock-less lock. */
osc_lock_to_lockless(env, olck, 1);
olck->ols_state = OLS_GRANTED;
rc = 0;
} else if (olck->ols_glimpse && rc == -ENAVAIL) {
osc_lock_lvb_update(env, olck, rc);
cl_lock_delete(env, lock);
/* Hide the error. */
rc = 0;
}
if (rc == 0) {
/* For AGL case, the RPC sponsor may exits the cl_lock
* processing without wait() called before related OSC
* lock upcall(). So update the lock status according
* to the enqueue result inside AGL upcall(). */
if (olck->ols_agl) {
lock->cll_flags |= CLF_FROM_UPCALL;
cl_wait_try(env, lock);
lock->cll_flags &= ~CLF_FROM_UPCALL;
if (!olck->ols_glimpse)
olck->ols_agl = 0;
}
cl_lock_signal(env, lock);
/* del user for lock upcall cookie */
cl_unuse_try(env, lock);
} else {
/* del user for lock upcall cookie */
cl_lock_user_del(env, lock);
cl_lock_error(env, lock, rc);
}
/* release cookie reference, acquired by osc_lock_enqueue() */
cl_lock_hold_release(env, lock, "upcall", lock);
cl_lock_mutex_put(env, lock);
lu_ref_del(&lock->cll_reference, "upcall", lock);
/* This maybe the last reference, so must be called after
* cl_lock_mutex_put(). */
cl_lock_put(env, lock);
cl_env_nested_put(&nest, env);
} else {
/* should never happen, similar to osc_ldlm_blocking_ast(). */
LBUG();
}
return errcode;
}
/**
* Core of osc_dlm_blocking_ast() logic.
*/
static void osc_lock_blocking(const struct lu_env *env,
struct ldlm_lock *dlmlock,
struct osc_lock *olck, int blocking)
{
struct cl_lock *lock = olck->ols_cl.cls_lock;
LASSERT(olck->ols_lock == dlmlock);
CLASSERT(OLS_BLOCKED < OLS_CANCELLED);
LASSERT(!osc_lock_is_lockless(olck));
/*
* Lock might be still addref-ed here, if e.g., blocking ast
* is sent for a failed lock.
*/
osc_lock_unhold(olck);
if (blocking && olck->ols_state < OLS_BLOCKED)
/*
* Move osc_lock into OLS_BLOCKED before canceling the lock,
* because it recursively re-enters osc_lock_blocking(), with
* the state set to OLS_CANCELLED.
*/
olck->ols_state = OLS_BLOCKED;
/*
* cancel and destroy lock at least once no matter how blocking ast is
* entered (see comment above osc_ldlm_blocking_ast() for use
* cases). cl_lock_cancel() and cl_lock_delete() are idempotent.
*/
cl_lock_cancel(env, lock);
cl_lock_delete(env, lock);
}
/**
* Helper for osc_dlm_blocking_ast() handling discrepancies between cl_lock
* and ldlm_lock caches.
*/
static int osc_dlm_blocking_ast0(const struct lu_env *env,
struct ldlm_lock *dlmlock,
void *data, int flag)
{
struct osc_lock *olck;
struct cl_lock *lock;
int result;
int cancel;
LASSERT(flag == LDLM_CB_BLOCKING || flag == LDLM_CB_CANCELING);
cancel = 0;
olck = osc_ast_data_get(dlmlock);
if (olck != NULL) {
lock = olck->ols_cl.cls_lock;
cl_lock_mutex_get(env, lock);
LINVRNT(osc_lock_invariant(olck));
if (olck->ols_ast_wait) {
/* wake up osc_lock_use() */
cl_lock_signal(env, lock);
olck->ols_ast_wait = 0;
}
/*
* Lock might have been canceled while this thread was
* sleeping for lock mutex, but olck is pinned in memory.
*/
if (olck == dlmlock->l_ast_data) {
/*
* NOTE: DLM sends blocking AST's for failed locks
* (that are still in pre-OLS_GRANTED state)
* too, and they have to be canceled otherwise
* DLM lock is never destroyed and stuck in
* the memory.
*
* Alternatively, ldlm_cli_cancel() can be
* called here directly for osc_locks with
* ols_state < OLS_GRANTED to maintain an
* invariant that ->clo_cancel() is only called
* for locks that were granted.
*/
LASSERT(data == olck);
osc_lock_blocking(env, dlmlock,
olck, flag == LDLM_CB_BLOCKING);
} else
cancel = 1;
cl_lock_mutex_put(env, lock);
osc_ast_data_put(env, olck);
} else
/*
* DLM lock exists, but there is no cl_lock attached to it.
* This is a `normal' race. cl_object and its cl_lock's can be
* removed by memory pressure, together with all pages.
*/
cancel = (flag == LDLM_CB_BLOCKING);
if (cancel) {
struct lustre_handle *lockh;
lockh = &osc_env_info(env)->oti_handle;
ldlm_lock2handle(dlmlock, lockh);
result = ldlm_cli_cancel(lockh, LCF_ASYNC);
} else
result = 0;
return result;
}
/**
* Blocking ast invoked by ldlm when dlm lock is either blocking progress of
* some other lock, or is canceled. This function is installed as a
* ldlm_lock::l_blocking_ast() for client extent locks.
*
* Control flow is tricky, because ldlm uses the same call-back
* (ldlm_lock::l_blocking_ast()) for both blocking and cancellation ast's.
*
* \param dlmlock lock for which ast occurred.
*
* \param new description of a conflicting lock in case of blocking ast.
*
* \param data value of dlmlock->l_ast_data
*
* \param flag LDLM_CB_BLOCKING or LDLM_CB_CANCELING. Used to distinguish
* cancellation and blocking ast's.
*
* Possible use cases:
*
* - ldlm calls dlmlock->l_blocking_ast(..., LDLM_CB_CANCELING) to cancel
* lock due to lock lru pressure, or explicit user request to purge
* locks.
*
* - ldlm calls dlmlock->l_blocking_ast(..., LDLM_CB_BLOCKING) to notify
* us that dlmlock conflicts with another lock that some client is
* enqueing. Lock is canceled.
*
* - cl_lock_cancel() is called. osc_lock_cancel() calls
* ldlm_cli_cancel() that calls
*
* dlmlock->l_blocking_ast(..., LDLM_CB_CANCELING)
*
* recursively entering osc_ldlm_blocking_ast().
*
* - client cancels lock voluntary (e.g., as a part of early cancellation):
*
* cl_lock_cancel()->
* osc_lock_cancel()->
* ldlm_cli_cancel()->
* dlmlock->l_blocking_ast(..., LDLM_CB_CANCELING)
*
*/
static int osc_ldlm_blocking_ast(struct ldlm_lock *dlmlock,
struct ldlm_lock_desc *new, void *data,
int flag)
{
struct lu_env *env;
struct cl_env_nest nest;
int result;
/*
* This can be called in the context of outer IO, e.g.,
*
* cl_enqueue()->...
* ->osc_enqueue_base()->...
* ->ldlm_prep_elc_req()->...
* ->ldlm_cancel_callback()->...
* ->osc_ldlm_blocking_ast()
*
* new environment has to be created to not corrupt outer context.
*/
env = cl_env_nested_get(&nest);
if (!IS_ERR(env)) {
result = osc_dlm_blocking_ast0(env, dlmlock, data, flag);
cl_env_nested_put(&nest, env);
} else {
result = PTR_ERR(env);
/*
* XXX This should never happen, as cl_lock is
* stuck. Pre-allocated environment a la vvp_inode_fini_env
* should be used.
*/
LBUG();
}
if (result != 0) {
if (result == -ENODATA)
result = 0;
else
CERROR("BAST failed: %d\n", result);
}
return result;
}
static int osc_ldlm_completion_ast(struct ldlm_lock *dlmlock,
__u64 flags, void *data)
{
struct cl_env_nest nest;
struct lu_env *env;
struct osc_lock *olck;
struct cl_lock *lock;
int result;
int dlmrc;
/* first, do dlm part of the work */
dlmrc = ldlm_completion_ast_async(dlmlock, flags, data);
/* then, notify cl_lock */
env = cl_env_nested_get(&nest);
if (!IS_ERR(env)) {
olck = osc_ast_data_get(dlmlock);
if (olck != NULL) {
lock = olck->ols_cl.cls_lock;
cl_lock_mutex_get(env, lock);
/*
* ldlm_handle_cp_callback() copied LVB from request
* to lock->l_lvb_data, store it in osc_lock.
*/
LASSERT(dlmlock->l_lvb_data != NULL);
lock_res_and_lock(dlmlock);
olck->ols_lvb = *(struct ost_lvb *)dlmlock->l_lvb_data;
if (olck->ols_lock == NULL) {
/*
* upcall (osc_lock_upcall()) hasn't yet been
* called. Do nothing now, upcall will bind
* olck to dlmlock and signal the waiters.
*
* This maintains an invariant that osc_lock
* and ldlm_lock are always bound when
* osc_lock is in OLS_GRANTED state.
*/
} else if (dlmlock->l_granted_mode ==
dlmlock->l_req_mode) {
osc_lock_granted(env, olck, dlmlock, dlmrc);
}
unlock_res_and_lock(dlmlock);
if (dlmrc != 0) {
CL_LOCK_DEBUG(D_ERROR, env, lock,
"dlmlock returned %d\n", dlmrc);
cl_lock_error(env, lock, dlmrc);
}
cl_lock_mutex_put(env, lock);
osc_ast_data_put(env, olck);
result = 0;
} else
result = -ELDLM_NO_LOCK_DATA;
cl_env_nested_put(&nest, env);
} else
result = PTR_ERR(env);
return dlmrc ?: result;
}
static int osc_ldlm_glimpse_ast(struct ldlm_lock *dlmlock, void *data)
{
struct ptlrpc_request *req = data;
struct osc_lock *olck;
struct cl_lock *lock;
struct cl_object *obj;
struct cl_env_nest nest;
struct lu_env *env;
struct ost_lvb *lvb;
struct req_capsule *cap;
int result;
LASSERT(lustre_msg_get_opc(req->rq_reqmsg) == LDLM_GL_CALLBACK);
env = cl_env_nested_get(&nest);
if (!IS_ERR(env)) {
/* osc_ast_data_get() has to go after environment is
* allocated, because osc_ast_data() acquires a
* reference to a lock, and it can only be released in
* environment.
*/
olck = osc_ast_data_get(dlmlock);
if (olck != NULL) {
lock = olck->ols_cl.cls_lock;
/* Do not grab the mutex of cl_lock for glimpse.
* See LU-1274 for details.
* BTW, it's okay for cl_lock to be cancelled during
* this period because server can handle this race.
* See ldlm_server_glimpse_ast() for details.
* cl_lock_mutex_get(env, lock); */
cap = &req->rq_pill;
req_capsule_extend(cap, &RQF_LDLM_GL_CALLBACK);
req_capsule_set_size(cap, &RMF_DLM_LVB, RCL_SERVER,
sizeof(*lvb));
result = req_capsule_server_pack(cap);
if (result == 0) {
lvb = req_capsule_server_get(cap, &RMF_DLM_LVB);
obj = lock->cll_descr.cld_obj;
result = cl_object_glimpse(env, obj, lvb);
}
if (!exp_connect_lvb_type(req->rq_export))
req_capsule_shrink(&req->rq_pill,
&RMF_DLM_LVB,
sizeof(struct ost_lvb_v1),
RCL_SERVER);
osc_ast_data_put(env, olck);
} else {
/*
* These errors are normal races, so we don't want to
* fill the console with messages by calling
* ptlrpc_error()
*/
lustre_pack_reply(req, 1, NULL, NULL);
result = -ELDLM_NO_LOCK_DATA;
}
cl_env_nested_put(&nest, env);
} else
result = PTR_ERR(env);
req->rq_status = result;
return result;
}
static unsigned long osc_lock_weigh(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
/*
* don't need to grab coh_page_guard since we don't care the exact #
* of pages..
*/
return cl_object_header(slice->cls_obj)->coh_pages;
}
static void osc_lock_build_einfo(const struct lu_env *env,
const struct cl_lock *clock,
struct osc_lock *lock,
struct ldlm_enqueue_info *einfo)
{
enum cl_lock_mode mode;
mode = clock->cll_descr.cld_mode;
if (mode == CLM_PHANTOM)
/*
* For now, enqueue all glimpse locks in read mode. In the
* future, client might choose to enqueue LCK_PW lock for
* glimpse on a file opened for write.
*/
mode = CLM_READ;
einfo->ei_type = LDLM_EXTENT;
einfo->ei_mode = osc_cl_lock2ldlm(mode);
einfo->ei_cb_bl = osc_ldlm_blocking_ast;
einfo->ei_cb_cp = osc_ldlm_completion_ast;
einfo->ei_cb_gl = osc_ldlm_glimpse_ast;
einfo->ei_cbdata = lock; /* value to be put into ->l_ast_data */
}
/**
* Determine if the lock should be converted into a lockless lock.
*
* Steps to check:
* - if the lock has an explicit requirement for a non-lockless lock;
* - if the io lock request type ci_lockreq;
* - send the enqueue rpc to ost to make the further decision;
* - special treat to truncate lockless lock
*
* Additional policy can be implemented here, e.g., never do lockless-io
* for large extents.
*/
static void osc_lock_to_lockless(const struct lu_env *env,
struct osc_lock *ols, int force)
{
struct cl_lock_slice *slice = &ols->ols_cl;
LASSERT(ols->ols_state == OLS_NEW ||
ols->ols_state == OLS_UPCALL_RECEIVED);
if (force) {
ols->ols_locklessable = 1;
slice->cls_ops = &osc_lock_lockless_ops;
} else {
struct osc_io *oio = osc_env_io(env);
struct cl_io *io = oio->oi_cl.cis_io;
struct cl_object *obj = slice->cls_obj;
struct osc_object *oob = cl2osc(obj);
const struct osc_device *osd = lu2osc_dev(obj->co_lu.lo_dev);
struct obd_connect_data *ocd;
LASSERT(io->ci_lockreq == CILR_MANDATORY ||
io->ci_lockreq == CILR_MAYBE ||
io->ci_lockreq == CILR_NEVER);
ocd = &class_exp2cliimp(osc_export(oob))->imp_connect_data;
ols->ols_locklessable = (io->ci_type != CIT_SETATTR) &&
(io->ci_lockreq == CILR_MAYBE) &&
(ocd->ocd_connect_flags & OBD_CONNECT_SRVLOCK);
if (io->ci_lockreq == CILR_NEVER ||
/* lockless IO */
(ols->ols_locklessable && osc_object_is_contended(oob)) ||
/* lockless truncate */
(cl_io_is_trunc(io) &&
(ocd->ocd_connect_flags & OBD_CONNECT_TRUNCLOCK) &&
osd->od_lockless_truncate)) {
ols->ols_locklessable = 1;
slice->cls_ops = &osc_lock_lockless_ops;
}
}
LASSERT(ergo(ols->ols_glimpse, !osc_lock_is_lockless(ols)));
}
static int osc_lock_compatible(const struct osc_lock *qing,
const struct osc_lock *qed)
{
enum cl_lock_mode qing_mode;
enum cl_lock_mode qed_mode;
qing_mode = qing->ols_cl.cls_lock->cll_descr.cld_mode;
if (qed->ols_glimpse &&
(qed->ols_state >= OLS_UPCALL_RECEIVED || qing_mode == CLM_READ))
return 1;
qed_mode = qed->ols_cl.cls_lock->cll_descr.cld_mode;
return ((qing_mode == CLM_READ) && (qed_mode == CLM_READ));
}
/**
* Cancel all conflicting locks and wait for them to be destroyed.
*
* This function is used for two purposes:
*
* - early cancel all conflicting locks before starting IO, and
*
* - guarantee that pages added to the page cache by lockless IO are never
* covered by locks other than lockless IO lock, and, hence, are not
* visible to other threads.
*/
static int osc_lock_enqueue_wait(const struct lu_env *env,
const struct osc_lock *olck)
{
struct cl_lock *lock = olck->ols_cl.cls_lock;
struct cl_lock_descr *descr = &lock->cll_descr;
struct cl_object_header *hdr = cl_object_header(descr->cld_obj);
struct cl_lock *scan;
struct cl_lock *conflict = NULL;
int lockless = osc_lock_is_lockless(olck);
int rc = 0;
LASSERT(cl_lock_is_mutexed(lock));
/* make it enqueue anyway for glimpse lock, because we actually
* don't need to cancel any conflicting locks. */
if (olck->ols_glimpse)
return 0;
spin_lock(&hdr->coh_lock_guard);
list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
struct cl_lock_descr *cld = &scan->cll_descr;
const struct osc_lock *scan_ols;
if (scan == lock)
break;
if (scan->cll_state < CLS_QUEUING ||
scan->cll_state == CLS_FREEING ||
cld->cld_start > descr->cld_end ||
cld->cld_end < descr->cld_start)
continue;
/* overlapped and living locks. */
/* We're not supposed to give up group lock. */
if (scan->cll_descr.cld_mode == CLM_GROUP) {
LASSERT(descr->cld_mode != CLM_GROUP ||
descr->cld_gid != scan->cll_descr.cld_gid);
continue;
}
scan_ols = osc_lock_at(scan);
/* We need to cancel the compatible locks if we're enqueuing
* a lockless lock, for example:
* imagine that client has PR lock on [0, 1000], and thread T0
* is doing lockless IO in [500, 1500] region. Concurrent
* thread T1 can see lockless data in [500, 1000], which is
* wrong, because these data are possibly stale. */
if (!lockless && osc_lock_compatible(olck, scan_ols))
continue;
cl_lock_get_trust(scan);
conflict = scan;
break;
}
spin_unlock(&hdr->coh_lock_guard);
if (conflict) {
if (lock->cll_descr.cld_mode == CLM_GROUP) {
/* we want a group lock but a previous lock request
* conflicts, we do not wait but return 0 so the
* request is send to the server
*/
CDEBUG(D_DLMTRACE, "group lock %p is conflicted with %p, no wait, send to server\n",
lock, conflict);
cl_lock_put(env, conflict);
rc = 0;
} else {
CDEBUG(D_DLMTRACE, "lock %p is conflicted with %p, will wait\n",
lock, conflict);
LASSERT(lock->cll_conflict == NULL);
lu_ref_add(&conflict->cll_reference, "cancel-wait",
lock);
lock->cll_conflict = conflict;
rc = CLO_WAIT;
}
}
return rc;
}
/**
* Implementation of cl_lock_operations::clo_enqueue() method for osc
* layer. This initiates ldlm enqueue:
*
* - cancels conflicting locks early (osc_lock_enqueue_wait());
*
* - calls osc_enqueue_base() to do actual enqueue.
*
* osc_enqueue_base() is supplied with an upcall function that is executed
* when lock is received either after a local cached ldlm lock is matched, or
* when a reply from the server is received.
*
* This function does not wait for the network communication to complete.
*/
static int osc_lock_enqueue(const struct lu_env *env,
const struct cl_lock_slice *slice,
struct cl_io *unused, __u32 enqflags)
{
struct osc_lock *ols = cl2osc_lock(slice);
struct cl_lock *lock = ols->ols_cl.cls_lock;
int result;
LASSERT(cl_lock_is_mutexed(lock));
LASSERTF(ols->ols_state == OLS_NEW,
"Impossible state: %d\n", ols->ols_state);
LASSERTF(ergo(ols->ols_glimpse, lock->cll_descr.cld_mode <= CLM_READ),
"lock = %p, ols = %p\n", lock, ols);
result = osc_lock_enqueue_wait(env, ols);
if (result == 0) {
if (!osc_lock_is_lockless(ols)) {
struct osc_object *obj = cl2osc(slice->cls_obj);
struct osc_thread_info *info = osc_env_info(env);
struct ldlm_res_id *resname = &info->oti_resname;
ldlm_policy_data_t *policy = &info->oti_policy;
struct ldlm_enqueue_info *einfo = &ols->ols_einfo;
/* lock will be passed as upcall cookie,
* hold ref to prevent to be released. */
cl_lock_hold_add(env, lock, "upcall", lock);
/* a user for lock also */
cl_lock_user_add(env, lock);
ols->ols_state = OLS_ENQUEUED;
/*
* XXX: this is possible blocking point as
* ldlm_lock_match(LDLM_FL_LVB_READY) waits for
* LDLM_CP_CALLBACK.
*/
ostid_build_res_name(&obj->oo_oinfo->loi_oi, resname);
osc_lock_build_policy(env, lock, policy);
result = osc_enqueue_base(osc_export(obj), resname,
&ols->ols_flags, policy,
&ols->ols_lvb,
obj->oo_oinfo->loi_kms_valid,
osc_lock_upcall,
ols, einfo, &ols->ols_handle,
PTLRPCD_SET, 1, ols->ols_agl);
if (result != 0) {
cl_lock_user_del(env, lock);
cl_lock_unhold(env, lock, "upcall", lock);
if (unlikely(result == -ECANCELED)) {
ols->ols_state = OLS_NEW;
result = 0;
}
}
} else {
ols->ols_state = OLS_GRANTED;
ols->ols_owner = osc_env_io(env);
}
}
LASSERT(ergo(ols->ols_glimpse, !osc_lock_is_lockless(ols)));
return result;
}
static int osc_lock_wait(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *olck = cl2osc_lock(slice);
struct cl_lock *lock = olck->ols_cl.cls_lock;
LINVRNT(osc_lock_invariant(olck));
if (olck->ols_glimpse && olck->ols_state >= OLS_UPCALL_RECEIVED) {
if (olck->ols_flags & LDLM_FL_LVB_READY) {
return 0;
} else if (olck->ols_agl) {
if (lock->cll_flags & CLF_FROM_UPCALL)
/* It is from enqueue RPC reply upcall for
* updating state. Do not re-enqueue. */
return -ENAVAIL;
else
olck->ols_state = OLS_NEW;
} else {
LASSERT(lock->cll_error);
return lock->cll_error;
}
}
if (olck->ols_state == OLS_NEW) {
int rc;
LASSERT(olck->ols_agl);
olck->ols_agl = 0;
olck->ols_flags &= ~LDLM_FL_BLOCK_NOWAIT;
rc = osc_lock_enqueue(env, slice, NULL, CEF_ASYNC | CEF_MUST);
if (rc != 0)
return rc;
else
return CLO_REENQUEUED;
}
LASSERT(equi(olck->ols_state >= OLS_UPCALL_RECEIVED &&
lock->cll_error == 0, olck->ols_lock != NULL));
return lock->cll_error ?: olck->ols_state >= OLS_GRANTED ? 0 : CLO_WAIT;
}
/**
* An implementation of cl_lock_operations::clo_use() method that pins cached
* lock.
*/
static int osc_lock_use(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *olck = cl2osc_lock(slice);
int rc;
LASSERT(!olck->ols_hold);
/*
* Atomically check for LDLM_FL_CBPENDING and addref a lock if this
* flag is not set. This protects us from a concurrent blocking ast.
*/
rc = ldlm_lock_addref_try(&olck->ols_handle, olck->ols_einfo.ei_mode);
if (rc == 0) {
olck->ols_hold = 1;
olck->ols_state = OLS_GRANTED;
} else {
struct cl_lock *lock;
/*
* Lock is being cancelled somewhere within
* ldlm_handle_bl_callback(): LDLM_FL_CBPENDING is already
* set, but osc_ldlm_blocking_ast() hasn't yet acquired
* cl_lock mutex.
*/
lock = slice->cls_lock;
LASSERT(lock->cll_state == CLS_INTRANSIT);
LASSERT(lock->cll_users > 0);
/* set a flag for osc_dlm_blocking_ast0() to signal the
* lock.*/
olck->ols_ast_wait = 1;
rc = CLO_WAIT;
}
return rc;
}
static int osc_lock_flush(struct osc_lock *ols, int discard)
{
struct cl_lock *lock = ols->ols_cl.cls_lock;
struct cl_env_nest nest;
struct lu_env *env;
int result = 0;
env = cl_env_nested_get(&nest);
if (!IS_ERR(env)) {
struct osc_object *obj = cl2osc(ols->ols_cl.cls_obj);
struct cl_lock_descr *descr = &lock->cll_descr;
int rc = 0;
if (descr->cld_mode >= CLM_WRITE) {
result = osc_cache_writeback_range(env, obj,
descr->cld_start, descr->cld_end,
1, discard);
LDLM_DEBUG(ols->ols_lock,
"lock %p: %d pages were %s.\n", lock, result,
discard ? "discarded" : "written");
if (result > 0)
result = 0;
}
rc = cl_lock_discard_pages(env, lock);
if (result == 0 && rc < 0)
result = rc;
cl_env_nested_put(&nest, env);
} else
result = PTR_ERR(env);
if (result == 0) {
ols->ols_flush = 1;
LINVRNT(!osc_lock_has_pages(ols));
}
return result;
}
/**
* Implements cl_lock_operations::clo_cancel() method for osc layer. This is
* called (as part of cl_lock_cancel()) when lock is canceled either voluntary
* (LRU pressure, early cancellation, umount, etc.) or due to the conflict
* with some other lock some where in the cluster. This function does the
* following:
*
* - invalidates all pages protected by this lock (after sending dirty
* ones to the server, as necessary);
*
* - decref's underlying ldlm lock;
*
* - cancels ldlm lock (ldlm_cli_cancel()).
*/
static void osc_lock_cancel(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct cl_lock *lock = slice->cls_lock;
struct osc_lock *olck = cl2osc_lock(slice);
struct ldlm_lock *dlmlock = olck->ols_lock;
int result = 0;
int discard;
LASSERT(cl_lock_is_mutexed(lock));
LINVRNT(osc_lock_invariant(olck));
if (dlmlock != NULL) {
int do_cancel;
discard = !!(dlmlock->l_flags & LDLM_FL_DISCARD_DATA);
if (olck->ols_state >= OLS_GRANTED)
result = osc_lock_flush(olck, discard);
osc_lock_unhold(olck);
lock_res_and_lock(dlmlock);
/* Now that we're the only user of dlm read/write reference,
* mostly the ->l_readers + ->l_writers should be zero.
* However, there is a corner case.
* See bug 18829 for details.*/
do_cancel = (dlmlock->l_readers == 0 &&
dlmlock->l_writers == 0);
dlmlock->l_flags |= LDLM_FL_CBPENDING;
unlock_res_and_lock(dlmlock);
if (do_cancel)
result = ldlm_cli_cancel(&olck->ols_handle, LCF_ASYNC);
if (result < 0)
CL_LOCK_DEBUG(D_ERROR, env, lock,
"lock %p cancel failure with error(%d)\n",
lock, result);
}
olck->ols_state = OLS_CANCELLED;
olck->ols_flags &= ~LDLM_FL_LVB_READY;
osc_lock_detach(env, olck);
}
static int osc_lock_has_pages(struct osc_lock *olck)
{
return 0;
}
static void osc_lock_delete(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *olck;
olck = cl2osc_lock(slice);
if (olck->ols_glimpse) {
LASSERT(!olck->ols_hold);
LASSERT(!olck->ols_lock);
return;
}
LINVRNT(osc_lock_invariant(olck));
LINVRNT(!osc_lock_has_pages(olck));
osc_lock_unhold(olck);
osc_lock_detach(env, olck);
}
/**
* Implements cl_lock_operations::clo_state() method for osc layer.
*
* Maintains osc_lock::ols_owner field.
*
* This assumes that lock always enters CLS_HELD (from some other state) in
* the same IO context as one that requested the lock. This should not be a
* problem, because context is by definition shared by all activity pertaining
* to the same high-level IO.
*/
static void osc_lock_state(const struct lu_env *env,
const struct cl_lock_slice *slice,
enum cl_lock_state state)
{
struct osc_lock *lock = cl2osc_lock(slice);
/*
* XXX multiple io contexts can use the lock at the same time.
*/
LINVRNT(osc_lock_invariant(lock));
if (state == CLS_HELD && slice->cls_lock->cll_state != CLS_HELD) {
struct osc_io *oio = osc_env_io(env);
LASSERT(lock->ols_owner == NULL);
lock->ols_owner = oio;
} else if (state != CLS_HELD)
lock->ols_owner = NULL;
}
static int osc_lock_print(const struct lu_env *env, void *cookie,
lu_printer_t p, const struct cl_lock_slice *slice)
{
struct osc_lock *lock = cl2osc_lock(slice);
/*
* XXX print ldlm lock and einfo properly.
*/
(*p)(env, cookie, "%p %#16llx %#llx %d %p ",
lock->ols_lock, lock->ols_flags, lock->ols_handle.cookie,
lock->ols_state, lock->ols_owner);
osc_lvb_print(env, cookie, p, &lock->ols_lvb);
return 0;
}
static int osc_lock_fits_into(const struct lu_env *env,
const struct cl_lock_slice *slice,
const struct cl_lock_descr *need,
const struct cl_io *io)
{
struct osc_lock *ols = cl2osc_lock(slice);
if (need->cld_enq_flags & CEF_NEVER)
return 0;
if (ols->ols_state >= OLS_CANCELLED)
return 0;
if (need->cld_mode == CLM_PHANTOM) {
if (ols->ols_agl)
return !(ols->ols_state > OLS_RELEASED);
/*
* Note: the QUEUED lock can't be matched here, otherwise
* it might cause the deadlocks.
* In read_process,
* P1: enqueued read lock, create sublock1
* P2: enqueued write lock, create sublock2(conflicted
* with sublock1).
* P1: Grant read lock.
* P1: enqueued glimpse lock(with holding sublock1_read),
* matched with sublock2, waiting sublock2 to be granted.
* But sublock2 can not be granted, because P1
* will not release sublock1. Bang!
*/
if (ols->ols_state < OLS_GRANTED ||
ols->ols_state > OLS_RELEASED)
return 0;
} else if (need->cld_enq_flags & CEF_MUST) {
/*
* If the lock hasn't ever enqueued, it can't be matched
* because enqueue process brings in many information
* which can be used to determine things such as lockless,
* CEF_MUST, etc.
*/
if (ols->ols_state < OLS_UPCALL_RECEIVED &&
ols->ols_locklessable)
return 0;
}
return 1;
}
static const struct cl_lock_operations osc_lock_ops = {
.clo_fini = osc_lock_fini,
.clo_enqueue = osc_lock_enqueue,
.clo_wait = osc_lock_wait,
.clo_unuse = osc_lock_unuse,
.clo_use = osc_lock_use,
.clo_delete = osc_lock_delete,
.clo_state = osc_lock_state,
.clo_cancel = osc_lock_cancel,
.clo_weigh = osc_lock_weigh,
.clo_print = osc_lock_print,
.clo_fits_into = osc_lock_fits_into,
};
static int osc_lock_lockless_unuse(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
struct cl_lock *lock = slice->cls_lock;
LASSERT(ols->ols_state == OLS_GRANTED);
LINVRNT(osc_lock_invariant(ols));
cl_lock_cancel(env, lock);
cl_lock_delete(env, lock);
return 0;
}
static void osc_lock_lockless_cancel(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
int result;
result = osc_lock_flush(ols, 0);
if (result)
CERROR("Pages for lockless lock %p were not purged(%d)\n",
ols, result);
ols->ols_state = OLS_CANCELLED;
}
static int osc_lock_lockless_wait(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *olck = cl2osc_lock(slice);
struct cl_lock *lock = olck->ols_cl.cls_lock;
LINVRNT(osc_lock_invariant(olck));
LASSERT(olck->ols_state >= OLS_UPCALL_RECEIVED);
return lock->cll_error;
}
static void osc_lock_lockless_state(const struct lu_env *env,
const struct cl_lock_slice *slice,
enum cl_lock_state state)
{
struct osc_lock *lock = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(lock));
if (state == CLS_HELD) {
struct osc_io *oio = osc_env_io(env);
LASSERT(ergo(lock->ols_owner, lock->ols_owner == oio));
lock->ols_owner = oio;
/* set the io to be lockless if this lock is for io's
* host object */
if (cl_object_same(oio->oi_cl.cis_obj, slice->cls_obj))
oio->oi_lockless = 1;
}
}
static int osc_lock_lockless_fits_into(const struct lu_env *env,
const struct cl_lock_slice *slice,
const struct cl_lock_descr *need,
const struct cl_io *io)
{
struct osc_lock *lock = cl2osc_lock(slice);
if (!(need->cld_enq_flags & CEF_NEVER))
return 0;
/* lockless lock should only be used by its owning io. b22147 */
return (lock->ols_owner == osc_env_io(env));
}
static const struct cl_lock_operations osc_lock_lockless_ops = {
.clo_fini = osc_lock_fini,
.clo_enqueue = osc_lock_enqueue,
.clo_wait = osc_lock_lockless_wait,
.clo_unuse = osc_lock_lockless_unuse,
.clo_state = osc_lock_lockless_state,
.clo_fits_into = osc_lock_lockless_fits_into,
.clo_cancel = osc_lock_lockless_cancel,
.clo_print = osc_lock_print
};
int osc_lock_init(const struct lu_env *env,
struct cl_object *obj, struct cl_lock *lock,
const struct cl_io *unused)
{
struct osc_lock *clk;
int result;
OBD_SLAB_ALLOC_PTR_GFP(clk, osc_lock_kmem, GFP_NOFS);
if (clk != NULL) {
__u32 enqflags = lock->cll_descr.cld_enq_flags;
osc_lock_build_einfo(env, lock, clk, &clk->ols_einfo);
atomic_set(&clk->ols_pageref, 0);
clk->ols_state = OLS_NEW;
clk->ols_flags = osc_enq2ldlm_flags(enqflags);
clk->ols_agl = !!(enqflags & CEF_AGL);
if (clk->ols_agl)
clk->ols_flags |= LDLM_FL_BLOCK_NOWAIT;
if (clk->ols_flags & LDLM_FL_HAS_INTENT)
clk->ols_glimpse = 1;
cl_lock_slice_add(lock, &clk->ols_cl, obj, &osc_lock_ops);
if (!(enqflags & CEF_MUST))
/* try to convert this lock to a lockless lock */
osc_lock_to_lockless(env, clk, (enqflags & CEF_NEVER));
if (clk->ols_locklessable && !(enqflags & CEF_DISCARD_DATA))
clk->ols_flags |= LDLM_FL_DENY_ON_CONTENTION;
LDLM_DEBUG_NOLOCK("lock %p, osc lock %p, flags %llx\n",
lock, clk, clk->ols_flags);
result = 0;
} else
result = -ENOMEM;
return result;
}
int osc_dlm_lock_pageref(struct ldlm_lock *dlm)
{
struct osc_lock *olock;
int rc = 0;
spin_lock(&osc_ast_guard);
olock = dlm->l_ast_data;
/*
* there's a very rare race with osc_page_addref_lock(), but that
* doesn't matter because in the worst case we don't cancel a lock
* which we actually can, that's no harm.
*/
if (olock != NULL &&
atomic_add_return(_PAGEREF_MAGIC,
&olock->ols_pageref) != _PAGEREF_MAGIC) {
atomic_sub(_PAGEREF_MAGIC, &olock->ols_pageref);
rc = 1;
}
spin_unlock(&osc_ast_guard);
return rc;
}
/** @} osc */