Viewing: ldlm_request.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/
*/
/*
* This file contains Asynchronous System Trap (AST) handlers and related
* LDLM request-processing routines.
*
* An AST is a callback issued on a lock when its state is changed. There are
* several different types of ASTs (callbacks) registered for each lock:
*
* - completion AST: when a lock is enqueued by some process, but cannot be
* granted immediately due to other conflicting locks on the same resource,
* the completion AST is sent to notify the caller when the lock is
* eventually granted
*
* - blocking AST: when a lock is granted to some process, if another process
* enqueues a conflicting (blocking) lock on a resource, a blocking AST is
* sent to notify the holder(s) of the lock(s) of the conflicting lock
* request. The lock holder(s) must release their lock(s) on that resource in
* a timely manner or be evicted by the server.
*
* - glimpse AST: this is used when a process wants information about a lock
* (i.e. the lock value block (LVB)) but does not necessarily require holding
* the lock. If the resource is locked, the lock holder(s) are sent glimpse
* ASTs and the LVB is returned to the caller, and lock holder(s) may CANCEL
* their lock(s) if they are idle. If the resource is not locked, the server
* may grant the lock.
*/
#define DEBUG_SUBSYSTEM S_LDLM
#include <linux/fs_struct.h>
#include <lustre_errno.h>
#include <lustre_dlm.h>
#include <obd_class.h>
#include <obd.h>
#include "ldlm_internal.h"
unsigned int ldlm_enqueue_min = OBD_TIMEOUT_DEFAULT;
module_param(ldlm_enqueue_min, uint, 0644);
MODULE_PARM_DESC(ldlm_enqueue_min, "lock enqueue timeout minimum");
EXPORT_SYMBOL(ldlm_enqueue_min);
/* in client side, whether the cached locks will be canceled before replay */
unsigned int ldlm_cancel_unused_locks_before_replay = 1;
struct lock_wait_data {
struct ldlm_lock *lwd_lock;
__u32 lwd_conn_cnt;
};
struct ldlm_async_args {
struct lustre_handle lock_handle;
};
/**
* ldlm_request_bufsize() - Get size of request buffer
* @count: total number of lock handles to include for cancel
* @type: LDLM RPC request type
*
* If opcode=LDLM_ENQUEUE, 1 slot is already occupied,
* LDLM_LOCKREQ_HANDLE -1 slots are available.
* Otherwise, LDLM_LOCKREQ_HANDLE slots are available.
*
* Returns size of the request buffer
*/
static int ldlm_request_bufsize(int count, int type)
{
if (type == LDLM_ENQUEUE)
count++;
/* keep minimum handles to keep struct size for compatibility */
if (count < LDLM_LOCKREQ_HANDLES)
count = LDLM_LOCKREQ_HANDLES;
return offsetof(struct ldlm_request, lock_handle[count]);
}
static void ldlm_expired_completion_wait(struct lock_wait_data *lwd)
{
struct ldlm_lock *lock = lwd->lwd_lock;
struct obd_import *imp;
struct obd_device *obd;
ENTRY;
if (lock->l_conn_export == NULL) {
static time64_t next_dump, last_dump;
LDLM_ERROR(lock,
"lock timed out (enqueued at %lld, %llds ago); not entering recovery in server code, just going back to sleep",
lock->l_activity,
ktime_get_real_seconds() - lock->l_activity);
if (ktime_get_seconds() > next_dump) {
last_dump = next_dump;
next_dump = ktime_get_seconds() + 300;
ldlm_namespace_dump(D_DLMTRACE,
ldlm_lock_to_ns(lock));
if (last_dump == 0)
libcfs_debug_dumplog();
}
RETURN_EXIT;
}
obd = lock->l_conn_export->exp_obd;
imp = obd->u.cli.cl_import;
ptlrpc_fail_import(imp, lwd->lwd_conn_cnt);
LDLM_ERROR(lock,
"lock timed out (enqueued at %lld, %llds ago), entering recovery for %s@%s",
lock->l_activity,
ktime_get_real_seconds() - lock->l_activity,
obd2cli_tgt(obd),
libcfs_nidstr(&imp->imp_connection->c_peer.nid));
EXIT;
}
int is_granted_or_cancelled_nolock(struct ldlm_lock *lock)
{
int ret = 0;
check_res_locked(lock->l_resource);
if (ldlm_is_granted(lock) && !ldlm_is_cp_reqd(lock))
ret = 1;
else if (ldlm_is_failed(lock) || ldlm_is_cancel(lock))
ret = 1;
return ret;
}
EXPORT_SYMBOL(is_granted_or_cancelled_nolock);
/**
* ldlm_cp_timeout() - Calculate the Completion timeout
* @lock: lock which is waiting the completion callback
*
* Calculate the Completion timeout (covering enqueue, BL AST, data flush,
* lock cancel, and their replies). Used for lock completion timeout on the
* client side.
*
* We use the same basis for both server side and client side functions
* from a single node.
*
* Returns timeout in seconds to wait for the server reply
*/
static timeout_t ldlm_cp_timeout(struct ldlm_lock *lock)
{
timeout_t timeout;
struct obd_device *obd;
obd = class_exp2obd(lock->l_conn_export);
if (obd_at_off(obd))
return obd_timeout;
/*
* Wait a long time for enqueue - server may have to callback a
* lock from another client. Server will evict the other client if it
* doesn't respond reasonably, and then give us the lock.
*/
timeout = obd_at_get(obd, ldlm_lock_to_ns_at(lock));
return max(3 * timeout, (timeout_t)obd_get_ldlm_enqueue_min(obd));
}
/**
* ldlm_completion_tail() - Helper function for ldlm_completion_ast()
* @lock: lock which is being used for completion
* @data: If data is %NULL @lock was granted immediately without delay
*
* Helper function for ldlm_completion_ast(), updating timings when lock is
* actually granted.
*
* Return:
* * %0 on success
* * %negative on failure
*/
static int ldlm_completion_tail(struct ldlm_lock *lock, void *data)
{
int result = 0;
if (ldlm_is_destroyed(lock) || ldlm_is_failed(lock)) {
LDLM_DEBUG(lock, "client-side enqueue: destroyed");
result = -EIO;
} else if (data == NULL) {
LDLM_DEBUG(lock, "client-side enqueue: granted");
} else {
struct obd_device *obd = class_exp2obd(lock->l_conn_export);
/* Take into AT only CP RPC, not immediately granted locks */
timeout_t delay = 0;
/* Discard negative timeouts. We should also limit the
* maximum value of the timeout
*/
if (ktime_get_real_seconds() > lock->l_activity)
delay = ktime_get_real_seconds() - lock->l_activity;
LDLM_DEBUG(lock, "client-side enqueue: granted after %ds",
delay);
/* Update our time estimate */
obd_at_measure(obd, ldlm_lock_to_ns_at(lock), delay);
}
return result;
}
/**
* ldlm_completion_ast_async() - Lock completion handler
* @lock: lock which is being used for completion
* @flags: Flags related to lock operation
* @data: If data is %NULL @lock was granted immediately without delay
*
* Implementation of ->l_completion_ast() for a client, that doesn't wait
* until lock is granted. Suitable for locks enqueued through ptlrpcd, of
* other threads that cannot block for long.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_completion_ast_async(struct ldlm_lock *lock, __u64 flags, void *data)
{
ENTRY;
if (flags == LDLM_FL_WAIT_NOREPROC) {
LDLM_DEBUG(lock, "client-side enqueue waiting on pending lock");
RETURN(0);
}
if (!(flags & LDLM_FL_BLOCKED_MASK)) {
wake_up(&lock->l_waitq);
RETURN(ldlm_completion_tail(lock, data));
}
LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, going forward");
ldlm_reprocess_all(lock->l_resource, 0);
RETURN(0);
}
EXPORT_SYMBOL(ldlm_completion_ast_async);
/**
* ldlm_completion_ast() - Generic LDLM "completion" AST.
* @lock: lock for which completion ast occurred
* @flags: Flags related to lock operation
* @data: Additional data
*
* Generic LDLM "completion" AST. This is called in several cases:
*
* - when a reply to an ENQUEUE RPC is received from the server
* (ldlm_cli_enqueue_fini()). Lock might be granted or not granted at
* this point (determined by flags);
*
* - when LDLM_CP_CALLBACK RPC comes to client to notify it that lock has
* been granted;
*
* - when ldlm_lock_match(LDLM_FL_LVB_READY) is about to wait until lock
* gets correct lvb;
*
* - to force all locks when resource is destroyed (cleanup_resource());
*
* If lock is not granted in the first case, this function waits until second
* or penultimate cases happen in some other thread.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
{
/* XXX ALLOCATE - 160 bytes */
struct lock_wait_data lwd = {
.lwd_lock = NULL,
.lwd_conn_cnt = 0
};
struct obd_device *obd;
struct obd_import *imp = NULL;
timeout_t timeout;
int rc = 0;
ENTRY;
if (flags == LDLM_FL_WAIT_NOREPROC) {
LDLM_DEBUG(lock, "client-side enqueue waiting on pending lock");
goto noreproc;
}
if (!(flags & LDLM_FL_BLOCKED_MASK)) {
wake_up(&lock->l_waitq);
RETURN(0);
}
LDLM_DEBUG(lock, "client-side enqueue returned a blocked locksleeping");
noreproc:
obd = class_exp2obd(lock->l_conn_export);
/* if this is a local lock, then there is no import */
if (obd != NULL)
imp = obd->u.cli.cl_import;
timeout = ldlm_cp_timeout(lock);
lwd.lwd_lock = lock;
lock->l_activity = ktime_get_real_seconds();
if (imp != NULL) {
spin_lock(&imp->imp_lock);
lwd.lwd_conn_cnt = imp->imp_conn_cnt;
spin_unlock(&imp->imp_lock);
}
if (ns_is_client(ldlm_lock_to_ns(lock)) &&
CFS_FAIL_CHECK_RESET(OBD_FAIL_LDLM_INTR_CP_AST,
OBD_FAIL_LDLM_CP_BL_RACE | CFS_FAIL_ONCE)) {
ldlm_set_fail_loc(lock);
rc = -EINTR;
} else {
/* Go to sleep until the lock is granted or cancelled. */
if (ldlm_is_no_timeout(lock)) {
LDLM_DEBUG(lock, "waiting indefinitely because of NO_TIMEOUT");
rc = l_wait_event_abortable(
lock->l_waitq,
is_granted_or_cancelled(lock));
} else {
if (wait_event_idle_timeout(
lock->l_waitq,
is_granted_or_cancelled(lock),
cfs_time_seconds(timeout)) == 0) {
ldlm_expired_completion_wait(&lwd);
rc = l_wait_event_abortable(
lock->l_waitq,
is_granted_or_cancelled(lock));
}
}
}
if (rc) {
LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
rc);
RETURN(rc);
}
RETURN(ldlm_completion_tail(lock, data));
}
EXPORT_SYMBOL(ldlm_completion_ast);
/**
* ldlm_blocking_ast_nocheck() - A helper to build a blocking AST function
* @lock: the lock blocking or canceling AST was called on
*
* Perform a common operation for blocking ASTs: defferred lock cancellation.
* see mdt_blocking_ast
* see ldlm_blocking_ast
*
* Return %0 always
*/
int ldlm_blocking_ast_nocheck(struct ldlm_lock *lock)
{
int do_ast;
ENTRY;
ldlm_set_cbpending(lock);
do_ast = (!lock->l_readers && !lock->l_writers);
unlock_res_and_lock(lock);
if (do_ast) {
struct lustre_handle lockh;
int rc;
LDLM_DEBUG(lock, "already unused, calling ldlm_cli_cancel");
ldlm_lock2handle(lock, &lockh);
rc = ldlm_cli_cancel(&lockh, LCF_ASYNC);
if (rc < 0)
CERROR("ldlm_cli_cancel: %d\n", rc);
} else {
LDLM_DEBUG(lock,
"Lock still has references, will be cancelled later");
}
RETURN(0);
}
EXPORT_SYMBOL(ldlm_blocking_ast_nocheck);
/**
* ldlm_blocking_ast() - Server blocking AST
* @lock: LDLM lock structure (lock which blocks a request or cancelling lock)
* @desc: unused
* @data: unused
* @flag: indicates whether this cancelling or blocking callback
*
* ->l_blocking_ast() callback for LDLM locks acquired by server-side
* OBDs.
* see ldlm_blocking_ast_nocheck
*
* Return %0 always
*/
int ldlm_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
void *data, int flag)
{
ENTRY;
if (flag == LDLM_CB_CANCELING) {
/* Don't need to do anything here. */
RETURN(0);
}
lock_res_and_lock(lock);
/*
* Get this: if ldlm_blocking_ast is racing with intent_policy, such
* that ldlm_blocking_ast is called just before intent_policy method
* takes the lr_lock, then by the time we get the lock, we might not
* be the correct blocking function anymore. So check, and return
* early, if so.
*/
if (lock->l_blocking_ast != ldlm_blocking_ast) {
unlock_res_and_lock(lock);
RETURN(0);
}
RETURN(ldlm_blocking_ast_nocheck(lock));
}
EXPORT_SYMBOL(ldlm_blocking_ast);
/**
* ldlm_glimpse_ast() - Implements the l_glimpse_ast callback for DLM locks
* @lock: DLM lock being glimpsed (unused)
* @reqp: pointer to ptlrpc_request (unused)
*
* Implements ldlm_lock::l_glimpse_ast for extent locks acquired on the server.
*
* Returning -ELDLM_NO_LOCK_DATA actually works, but the reason for that is
* rather subtle: with OST-side locking, it may so happen that _all_ extent
* locks are held by the OST. If client wants to obtain the current file size
* it calls ll_glimpse_size(), and (as all locks are held only on the server),
* this dummy glimpse callback fires and does nothing. The client still
* receives the correct file size due to the following fragment of code in
* ldlm_cb_interpret():
*
* if (rc == -ELDLM_NO_LOCK_DATA) {
* LDLM_DEBUG(lock, "lost race - client has a lock but no"
* "inode");
* ldlm_res_lvbo_update(lock->l_resource, NULL, 1);
* }
*
* That is, after the glimpse returns this error, ofd_lvbo_update() is called
* and returns the updated file attributes from the inode to the client.
*
* See also comment in ofd_intent_policy() on why servers must set a non-NULL
* l_glimpse_ast when grabbing DLM locks. Otherwise, the server will assume
* that the object is in the process of being destroyed.
*
* Returns %-ELDLM_NO_LOCK_DATA to get attributes from disk object
*/
int ldlm_glimpse_ast(struct ldlm_lock *lock, void *reqp)
{
return -ELDLM_NO_LOCK_DATA;
}
/**
* ldlm_cli_enqueue_local() - Enqueue a local lock (typically on a server).
* @env: Lustre environment
* @ns: Pointer to the LDLM namespace
* @res_id: The resource name for the DLM request
* @type: Type of the lock (LDLM_PLAIN etc...)
* @policy: Lock policy
* @mode: Lock mode
* @flags: Lock operation flags
* @blocking: Blocking callback function
* @completion: Completion callback function
* @glimpse: Glimpse callback function
* @data: Data for lock
* @lvb_len: Length of the LVB
* @lvb_type: Type of LVB
* @client_cookie: Cookie from client
* @lockh: is the remote handle of the global lock
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_enqueue_local(const struct lu_env *env,
struct ldlm_namespace *ns,
const struct ldlm_res_id *res_id,
enum ldlm_type type, union ldlm_policy_data *policy,
enum ldlm_mode mode, __u64 *flags,
ldlm_blocking_callback blocking,
ldlm_completion_callback completion,
ldlm_glimpse_callback glimpse,
void *data, __u32 lvb_len, enum lvb_type lvb_type,
const __u64 *client_cookie,
struct lustre_handle *lockh)
{
struct ldlm_lock *lock;
int err;
const struct ldlm_callback_suite cbs = { .lcs_completion = completion,
.lcs_blocking = blocking,
.lcs_glimpse = glimpse,
};
ENTRY;
LASSERT(!(*flags & LDLM_FL_REPLAY));
LASSERTF(unlikely(!ns_is_client(ns)),
"Trying to enqueue local lock in a shadow namespace\n");
lock = ldlm_lock_create(ns, res_id, type, mode, &cbs, data, lvb_len,
lvb_type);
if (IS_ERR(lock))
GOTO(out_nolock, err = PTR_ERR(lock));
err = ldlm_lvbo_init(lock->l_resource);
if (err < 0) {
LDLM_ERROR(lock, "delayed lvb init failed (rc %d)", err);
ldlm_lock_destroy_nolock(lock);
GOTO(out, err);
}
ldlm_lock2handle(lock, lockh);
/*
* NB: we don't have any lock now (lock_res_and_lock)
* because it's a new lock
*/
ldlm_lock_addref_internal_nolock(lock, mode);
ldlm_set_local(lock);
if (*flags & LDLM_FL_ATOMIC_CB)
ldlm_set_atomic_cb(lock);
if (*flags & LDLM_FL_CANCEL_ON_BLOCK)
ldlm_set_cancel_on_block(lock);
if (policy != NULL)
lock->l_policy_data = *policy;
if (client_cookie != NULL)
lock->l_client_cookie = *client_cookie;
if (type == LDLM_EXTENT) {
LASSERT(policy);
lock->l_req_extent = policy->l_extent;
}
err = ldlm_lock_enqueue(env, ns, &lock, policy, flags);
if (unlikely(err != ELDLM_OK))
GOTO(out, err);
if (policy != NULL)
*policy = lock->l_policy_data;
if (lock->l_completion_ast)
lock->l_completion_ast(lock, *flags, NULL);
LDLM_DEBUG(lock, "client-side local enqueue handler, new lock created");
EXIT;
out:
ldlm_lock_put(lock);
out_nolock:
return err;
}
EXPORT_SYMBOL(ldlm_cli_enqueue_local);
static void failed_lock_cleanup(struct ldlm_namespace *ns,
struct ldlm_lock *lock, int mode)
{
int need_cancel = 0;
/* Set a flag to prevent us from sending a CANCEL (b=407) */
lock_res_and_lock(lock);
/* Check that lock is not granted or failed, we might race. */
if (!ldlm_is_granted(lock) && !ldlm_is_failed(lock)) {
/*
* Make sure that this lock will not be found by raced
* bl_ast and -EINVAL reply is sent to server anyways.
* b=17645
*/
lock->l_flags |= LDLM_FL_FAILED |
LDLM_FL_ATOMIC_CB | LDLM_FL_CBPENDING;
if (!(ldlm_is_bl_ast(lock) &&
lock->l_remote_handle.cookie != 0))
lock->l_flags |= LDLM_FL_LOCAL_ONLY;
need_cancel = 1;
}
unlock_res_and_lock(lock);
if (need_cancel)
LDLM_DEBUG(lock,
"setting FL_LOCAL_ONLY | LDLM_FL_FAILED | LDLM_FL_ATOMIC_CB | LDLM_FL_CBPENDING");
else
LDLM_DEBUG(lock, "lock was granted or failed in race");
/*
* XXX - HACK because we shouldn't call ldlm_lock_destroy()
* from llite/file.c/ll_file_flock().
*/
/*
* This code makes for the fact that we do not have blocking handler on
* a client for flock locks. As such this is the place where we must
* completely kill failed locks. (interrupted and those that
* were waiting to be granted when server evicted us.
*/
if (lock->l_resource->lr_type == LDLM_FLOCK) {
lock_res_and_lock(lock);
if (!ldlm_is_destroyed(lock)) {
ldlm_resource_unlink_lock(lock);
ldlm_lock_decref_internal_nolock(lock, mode);
ldlm_lock_destroy_nolock(lock);
}
unlock_res_and_lock(lock);
} else {
ldlm_lock_decref_internal(lock, mode);
}
}
static bool ldlm_request_slot_needed(struct ldlm_enqueue_info *einfo)
{
/* exclude EXTENT locks and DOM-only IBITS locks because they
* are asynchronous and don't wait on server being blocked.
*/
return einfo->ei_req_slot &&
(einfo->ei_type == LDLM_FLOCK ||
(einfo->ei_type == LDLM_IBITS &&
einfo->ei_inodebits != MDS_INODELOCK_DOM));
}
/**
* ldlm_cli_enqueue_fini() - Finishing portion of client lock enqueue code.
* @exp: OBD export struct
* @pill: RPC message data from the server (LDLM reply)
* @einfo: Common ldlm_enqueue parameters
* @with_policy: Lock policy
* @ldlm_flags: Lock operation flags
* @lvb: Pointer to LVB
* @lvb_len: Length of the LVB
* @lockh: is the remote handle of the global lock
* @rc: Return code from RPC communication with the server [out]
* @request_slot: If %True allocate slot and free
*
* Called after receiving reply from server.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_enqueue_fini(struct obd_export *exp, struct req_capsule *pill,
struct ldlm_enqueue_info *einfo,
__u8 with_policy, __u64 *ldlm_flags, void *lvb,
__u32 lvb_len, const struct lustre_handle *lockh,
int rc, bool request_slot)
{
struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
const struct lu_env *env = NULL;
int is_replay = *ldlm_flags & LDLM_FL_REPLAY;
struct ldlm_lock *lock;
struct ldlm_reply *reply;
int cleanup_phase = 1;
ENTRY;
if (req_capsule_ptlreq(pill)) {
struct ptlrpc_request *req = pill->rc_req;
if (request_slot)
obd_put_request_slot(&req->rq_import->imp_obd->u.cli);
ptlrpc_put_mod_rpc_slot(req);
if (req && req->rq_svc_thread)
env = req->rq_svc_thread->t_env;
}
lock = ldlm_handle2lock(lockh);
/* ldlm_cli_enqueue is holding a reference on this lock. */
if (!lock) {
LASSERT(einfo->ei_type == LDLM_FLOCK);
RETURN(-ENOLCK);
}
LASSERTF(ergo(lvb_len != 0, lvb_len == lock->l_lvb_len),
"lvb_len = %u, l_lvb_len = %u\n", lvb_len, lock->l_lvb_len);
if (rc != ELDLM_OK) {
LASSERT(!is_replay);
LDLM_DEBUG(lock, "client-side enqueue END (%s)",
rc == ELDLM_LOCK_ABORTED ? "ABORTED" : "FAILED");
if (rc != ELDLM_LOCK_ABORTED)
GOTO(cleanup, rc);
}
/* Before we return, swab the reply */
reply = req_capsule_server_get(pill, &RMF_DLM_REP);
if (reply == NULL)
GOTO(cleanup, rc = -EPROTO);
if (lvb_len > 0) {
int size = 0;
size = req_capsule_get_size(pill, &RMF_DLM_LVB, RCL_SERVER);
if (size < 0) {
LDLM_ERROR(lock, "Fail to get lvb_len, rc = %d", size);
GOTO(cleanup, rc = size);
} else if (unlikely(size > lvb_len)) {
LDLM_ERROR(lock,
"Replied LVB is larger than expectation, expected = %d, replied = %d",
lvb_len, size);
GOTO(cleanup, rc = -EINVAL);
}
lvb_len = size;
}
if (rc == ELDLM_LOCK_ABORTED) {
if (lvb_len > 0 && lvb != NULL)
rc = ldlm_fill_lvb(lock, pill, RCL_SERVER,
lvb, lvb_len);
GOTO(cleanup, rc = rc ? : ELDLM_LOCK_ABORTED);
}
/* lock enqueued on the server */
cleanup_phase = 0;
lock_res_and_lock(lock);
/* Key change rehash lock in per-export hash with new key */
if (exp->exp_lock_hash) {
/*
* In the function below, .hs_keycmp resolves to
* ldlm_export_lock_keycmp()
*/
cfs_hash_rehash_key(exp->exp_lock_hash,
&lock->l_remote_handle,
&reply->lock_handle,
&lock->l_exp_hash);
} else {
lock->l_remote_handle = reply->lock_handle;
}
*ldlm_flags = ldlm_flags_from_wire(reply->lock_flags);
lock->l_flags |= ldlm_flags_from_wire(reply->lock_flags &
LDLM_FL_INHERIT_MASK);
unlock_res_and_lock(lock);
CDEBUG(D_INFO, "local: %p, remote cookie: %#llx, flags: %#llx\n",
lock, reply->lock_handle.cookie, *ldlm_flags);
/*
* If enqueue returned a blocked lock but the completion handler has
* already run, then it fixed up the resource and we don't need to do it
* again.
*/
if ((*ldlm_flags) & LDLM_FL_LOCK_CHANGED) {
int newmode = reply->lock_desc.l_req_mode;
LASSERT(!is_replay);
if (newmode && newmode != lock->l_req_mode) {
LDLM_DEBUG(lock, "server returned different mode %s",
ldlm_lockname[newmode]);
lock->l_req_mode = newmode;
}
if (!ldlm_res_eq(&reply->lock_desc.l_resource.lr_name,
&lock->l_resource->lr_name)) {
CDEBUG(D_INFO,
"remote intent success, locking "DLDLMRES", instead of "DLDLMRES"\n",
PLDLMRES(&reply->lock_desc.l_resource),
PLDLMRES(lock->l_resource));
rc = ldlm_lock_change_resource(ns, lock,
&reply->lock_desc.l_resource.lr_name);
if (rc || lock->l_resource == NULL)
GOTO(cleanup, rc = -ENOMEM);
LDLM_DEBUG(lock, "client-side enqueue, new resource");
}
if (with_policy) {
/* We assume lock type cannot change on server*/
ldlm_convert_policy_to_local(exp,
lock->l_resource->lr_type,
&reply->lock_desc.l_policy_data,
&lock->l_policy_data);
}
if (einfo->ei_type != LDLM_PLAIN)
LDLM_DEBUG(lock,
"client-side enqueue, new policy data");
}
if ((*ldlm_flags) & LDLM_FL_AST_SENT) {
lock_res_and_lock(lock);
ldlm_bl_desc2lock(&reply->lock_desc, lock);
lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_BL_AST;
unlock_res_and_lock(lock);
LDLM_DEBUG(lock, "enqueue reply includes blocking AST");
}
/*
* If the lock has already been granted by a completion AST, don't
* clobber the LVB with an older one.
*/
if (lvb_len > 0) {
/*
* We must lock or a racing completion might update lvb without
* letting us know and we'll clobber the correct value.
* Cannot unlock after the check either, a that still leaves
* a tiny window for completion to get in
*/
lock_res_and_lock(lock);
if (!ldlm_is_granted(lock))
rc = ldlm_fill_lvb(lock, pill, RCL_SERVER,
lock->l_lvb_data, lvb_len);
unlock_res_and_lock(lock);
if (rc < 0) {
cleanup_phase = 1;
GOTO(cleanup, rc);
}
}
if (!is_replay) {
rc = ldlm_lock_enqueue(env, ns, &lock, NULL, ldlm_flags);
if (lock->l_completion_ast != NULL) {
int err = lock->l_completion_ast(lock, *ldlm_flags,
NULL);
if (!rc)
rc = err;
if (rc)
cleanup_phase = 1;
}
}
if (lvb_len > 0 && lvb != NULL) {
/*
* Copy the LVB here, and not earlier, because the completion
* AST (if any) can override what we got in the reply
*/
memcpy(lvb, lock->l_lvb_data, lvb_len);
}
LDLM_DEBUG(lock, "client-side enqueue END");
EXIT;
cleanup:
if (cleanup_phase == 1 && rc)
failed_lock_cleanup(ns, lock, einfo->ei_mode);
/* Put lock 2 times, the second reference is held by ldlm_cli_enqueue */
ldlm_lock_put(lock);
ldlm_lock_put(lock);
return rc;
}
EXPORT_SYMBOL(ldlm_cli_enqueue_fini);
/*
* Estimate number of lock handles that would fit into request of given
* size. PAGE_SIZE-512 is to allow TCP/IP and LNET headers to fit into
* a single page on the send/receive side. XXX: 512 should be changed to
* more adequate value.
*/
static inline int ldlm_req_handles_avail(int req_size, int off)
{
int avail;
avail = min_t(int, LDLM_MAXREQSIZE, PAGE_SIZE - 512) - req_size;
if (likely(avail >= 0))
avail /= (int)sizeof(struct lustre_handle);
else
avail = 0;
avail += LDLM_LOCKREQ_HANDLES - off;
return avail;
}
static inline int ldlm_capsule_handles_avail(struct req_capsule *pill,
enum req_location loc,
int off)
{
__u32 size = req_capsule_msg_size(pill, loc);
return ldlm_req_handles_avail(size, off);
}
static inline int ldlm_format_handles_avail(struct obd_import *imp,
const struct req_format *fmt,
enum req_location loc, int off)
{
__u32 size = req_capsule_fmt_size(imp->imp_msg_magic, fmt, loc);
return ldlm_req_handles_avail(size, off);
}
/**
* ldlm_prep_elc_req() - Prepares Early Lock Cancel (ELC) request for LDLM locks
* @exp: OBD export struct
* @req: PTLRPC request
* @version: protocol version
* @opc: operation type
* @canceloff: Cancel offset (Offset from where to start canceling)
* @cancels: Cancel locks list
* @count: Number of locks to cancel
*
* Cancel LRU locks and pack them into the enqueue request. Pack there the given
* @count locks in @cancels.
*
* This is to be called by functions preparing their own requests that
* might contain lists of locks to cancel in addition to actual operation
* that needs to be performed.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_prep_elc_req(struct obd_export *exp, struct ptlrpc_request *req,
int version, int opc, int canceloff,
struct list_head *cancels, int count)
{
struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
struct req_capsule *pill = &req->rq_pill;
struct ldlm_request *dlm = NULL;
LIST_HEAD(head);
int avail, to_free = 0, pack = 0;
int rc;
ENTRY;
if (cancels == NULL)
cancels = &head;
if (ns_connect_cancelset(ns)) {
/* Estimate the amount of available space in the request. */
req_capsule_filled_sizes(pill, RCL_CLIENT);
avail = ldlm_capsule_handles_avail(pill, RCL_CLIENT, canceloff);
/* If we have reached the limit, free +1 slot for the new one */
if (!ns_connect_lru_resize(ns) && opc == LDLM_ENQUEUE &&
ns->ns_nr_unused >= ns->ns_max_unused)
to_free = 1;
/*
* Cancel LRU locks here _only_ if the server supports
* EARLY_CANCEL. Otherwise we have to send extra CANCEL
* RPC, which will make us slower.
*/
if (avail > count)
count += ldlm_cancel_lru_local(ns, cancels, to_free,
avail - count, 0,
LDLM_LRU_FLAG_NO_WAIT);
if (avail > count)
pack = count;
else
pack = avail;
req_capsule_set_size(pill, &RMF_DLM_REQ, RCL_CLIENT,
ldlm_request_bufsize(pack, opc));
}
rc = ptlrpc_request_pack(req, version, opc);
if (rc) {
ldlm_lock_list_put(cancels, l_bl_ast, count);
RETURN(rc);
}
if (ns_connect_cancelset(ns)) {
if (canceloff) {
dlm = req_capsule_client_get(pill, &RMF_DLM_REQ);
LASSERT(dlm);
/*
* Skip first lock handler in ldlm_request_pack(),
* this method will increment @lock_count according
* to the lock handle amount actually written to
* the buffer.
*/
dlm->lock_count = canceloff;
}
/* Pack into the request @pack lock handles. */
ldlm_cli_cancel_list(cancels, pack, NULL, req, 0);
/* Prepare and send separate cancel RPC for others. */
ldlm_cli_cancel_list(cancels, count - pack, NULL, NULL, 0);
} else {
ldlm_lock_list_put(cancels, l_bl_ast, count);
}
RETURN(0);
}
EXPORT_SYMBOL(ldlm_prep_elc_req);
int ldlm_prep_enqueue_req(struct obd_export *exp, struct ptlrpc_request *req,
struct list_head *cancels, int count)
{
return ldlm_prep_elc_req(exp, req, LUSTRE_DLM_VERSION, LDLM_ENQUEUE,
LDLM_ENQUEUE_CANCEL_OFF, cancels, count);
}
EXPORT_SYMBOL(ldlm_prep_enqueue_req);
struct ptlrpc_request *ldlm_enqueue_pack(struct obd_export *exp, int lvb_len)
{
struct ptlrpc_request *req;
int rc;
ENTRY;
req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_LDLM_ENQUEUE);
if (req == NULL)
RETURN(ERR_PTR(-ENOMEM));
rc = ldlm_prep_enqueue_req(exp, req, NULL, 0);
if (rc) {
ptlrpc_request_free(req);
RETURN(ERR_PTR(rc));
}
req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER, lvb_len);
ptlrpc_request_set_replen(req);
RETURN(req);
}
EXPORT_SYMBOL(ldlm_enqueue_pack);
static void ldlm_lock_add_to_enqueueing(struct ldlm_lock *lock)
{
struct ldlm_resource *res = lock->l_resource;
lock_res(res);
ldlm_resource_add_lock(res, &res->lr_enqueueing, lock);
unlock_res(res);
}
/**
* ldlm_cli_enqueue() - Client-side lock enqueue.
* @exp: OBD export struct
* @reqp: PTLRPC request
* @einfo: Common ldlm_enqueue parameters
* @res_id: Resource identifier
* @policy: Lock policy
* @flags: Lock operation flags
* @lvb: Pointer to LVB
* @lvb_len: Length of the LVB
* @lvb_type: Type of LVB
* @lockh: is the remote handle of the global lock
* @async: if %True request is asynchronous
*
* If a request has some specific initialisation it is passed in @reqp,
* otherwise it is created in ldlm_cli_enqueue.
*
* Supports sync and async requests, pass @async flag accordingly. If a
* request was created in ldlm_cli_enqueue and it is the async request,
* pass it to the caller in @reqp.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
struct ldlm_enqueue_info *einfo,
const struct ldlm_res_id *res_id,
union ldlm_policy_data const *policy, __u64 *flags,
void *lvb, __u32 lvb_len, enum lvb_type lvb_type,
struct lustre_handle *lockh, int async)
{
struct ldlm_namespace *ns;
struct ldlm_lock *lock;
struct ldlm_request *body;
int is_replay = *flags & LDLM_FL_REPLAY;
int req_passed_in = 1;
int rc, err;
bool need_req_slot;
struct ptlrpc_request *req;
ENTRY;
LASSERT(exp != NULL);
ns = exp->exp_obd->obd_namespace;
/*
* If we're replaying this lock, just check some invariants.
* If we're creating a new lock, get everything all setup nice.
*/
if (is_replay) {
lock = ldlm_handle2lock_long(lockh, 0);
LASSERT(lock != NULL);
LDLM_DEBUG(lock, "client-side enqueue START");
LASSERT(exp == lock->l_conn_export);
} else {
const struct ldlm_callback_suite cbs = {
.lcs_completion = einfo->ei_cb_cp,
.lcs_blocking = einfo->ei_cb_bl,
.lcs_glimpse = einfo->ei_cb_gl
};
lock = ldlm_lock_create(ns, res_id, einfo->ei_type,
einfo->ei_mode, &cbs, einfo->ei_cbdata,
lvb_len, lvb_type);
if (IS_ERR(lock))
RETURN(PTR_ERR(lock));
if (einfo->ei_cb_created)
einfo->ei_cb_created(lock);
/* for the local lock, add the reference */
ldlm_lock_addref_internal(lock, einfo->ei_mode);
ldlm_lock2handle(lock, lockh);
if (policy != NULL)
lock->l_policy_data = *policy;
if (einfo->ei_type == LDLM_EXTENT) {
LASSERT(policy);
lock->l_req_extent = policy->l_extent;
} else if (einfo->ei_type == LDLM_FLOCK) {
ldlm_lock_add_to_enqueueing(lock);
}
LDLM_DEBUG(lock, "client-side enqueue START, flags %#llx",
*flags);
}
lock->l_conn_export = exp;
lock->l_export = NULL;
lock->l_blocking_ast = einfo->ei_cb_bl;
lock->l_flags |= (*flags & (LDLM_FL_NO_LRU | LDLM_FL_EXCL));
lock->l_activity = ktime_get_real_seconds();
/* lock not sent to server yet */
if (reqp == NULL || *reqp == NULL) {
req = ldlm_enqueue_pack(exp, lvb_len);
if (IS_ERR(req)) {
failed_lock_cleanup(ns, lock, einfo->ei_mode);
ldlm_lock_put(lock);
RETURN(PTR_ERR(req));
}
req_passed_in = 0;
if (reqp)
*reqp = req;
} else {
int len;
req = *reqp;
len = req_capsule_get_size(&req->rq_pill, &RMF_DLM_REQ,
RCL_CLIENT);
LASSERTF(len >= sizeof(*body), "buflen[%d] = %d, not %d\n",
DLM_LOCKREQ_OFF, len, (int)sizeof(*body));
}
if (*flags & LDLM_FL_NDELAY) {
DEBUG_REQ(D_DLMTRACE, req, "enqueue lock with no delay");
req->rq_no_resend = req->rq_no_delay = 1;
/*
* probably set a shorter timeout value and handle ETIMEDOUT
* in osc_lock_upcall() correctly
*/
/* lustre_msg_set_timeout(req, req->rq_timeout / 2); */
}
/* Dump lock data into the request buffer */
body = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
ldlm_lock2desc(lock, &body->lock_desc);
body->lock_flags = ldlm_flags_to_wire(*flags);
body->lock_handle[0] = *lockh;
/* extended LDLM opcodes in client stats */
if (exp->exp_obd->obd_svc_stats != NULL) {
/* glimpse is intent with no intent buffer */
if (*flags & LDLM_FL_HAS_INTENT &&
!req_capsule_has_field(&req->rq_pill, &RMF_LDLM_INTENT,
RCL_CLIENT))
lprocfs_counter_incr(exp->exp_obd->obd_svc_stats,
PTLRPC_LAST_CNTR +
LDLM_GLIMPSE_ENQUEUE);
else
ldlm_svc_get_eopc(body, exp->exp_obd->obd_svc_stats);
}
/* It is important to obtain modify RPC slot first (if applicable), so
* that threads that are waiting for a modify RPC slot are not polluting
* our rpcs in flight counter. */
if (einfo->ei_mod_slot)
ptlrpc_get_mod_rpc_slot(req);
need_req_slot = ldlm_request_slot_needed(einfo);
if (need_req_slot) {
rc = obd_get_request_slot(&req->rq_import->imp_obd->u.cli);
if (rc) {
if (einfo->ei_mod_slot)
ptlrpc_put_mod_rpc_slot(req);
failed_lock_cleanup(ns, lock, einfo->ei_mode);
ldlm_lock_put(lock);
if (!req_passed_in)
ptlrpc_req_put(req);
GOTO(out, rc);
}
}
if (async) {
LASSERT(reqp != NULL);
RETURN(0);
}
LDLM_DEBUG(lock, "sending request");
rc = ptlrpc_queue_wait(req);
err = ldlm_cli_enqueue_fini(exp, &req->rq_pill, einfo, policy ? 1 : 0,
flags, lvb, lvb_len, lockh, rc,
need_req_slot);
/*
* If ldlm_cli_enqueue_fini did not find the lock, we need to free
* one reference that we took
*/
if (err == -ENOLCK)
ldlm_lock_put(lock);
else
rc = err;
out:
if (!req_passed_in && req != NULL) {
ptlrpc_req_put(req);
if (reqp)
*reqp = NULL;
}
RETURN(rc);
}
EXPORT_SYMBOL(ldlm_cli_enqueue);
/**
* ldlm_cli_lock_create_pack() - Client-side IBITS lock create and pack for
* WBC EX lock request.
* @exp: OBD export struct
* @dlmreq: LDLM request structure [out]
* @einfo: Common ldlm_enqueue parameters
* @res_id: The resource name for the DLM request
* @policy: Lock policy
* @flags: Lock operation flags
* @lvb: Pointer to LVB
* @lvb_len: Length of the LVB
* @lvb_type: Type of LVB
* @lockh: is the remote handle of the global lock
*
* Return %0 always
*/
int ldlm_cli_lock_create_pack(struct obd_export *exp,
struct ldlm_request *dlmreq,
struct ldlm_enqueue_info *einfo,
const struct ldlm_res_id *res_id,
union ldlm_policy_data const *policy,
__u64 *flags, void *lvb, __u32 lvb_len,
enum lvb_type lvb_type,
struct lustre_handle *lockh)
{
const struct ldlm_callback_suite cbs = {
.lcs_completion = einfo->ei_cb_cp,
.lcs_blocking = einfo->ei_cb_bl,
.lcs_glimpse = einfo->ei_cb_gl
};
struct ldlm_namespace *ns;
struct ldlm_lock *lock;
ENTRY;
LASSERT(exp != NULL);
LASSERT(!(*flags & LDLM_FL_REPLAY));
ns = exp->exp_obd->obd_namespace;
lock = ldlm_lock_create(ns, res_id, einfo->ei_type, einfo->ei_mode,
&cbs, einfo->ei_cbdata, lvb_len, lvb_type);
if (IS_ERR(lock))
RETURN(PTR_ERR(lock));
if (einfo->ei_cb_created)
einfo->ei_cb_created(lock);
/* For the local lock, add the reference */
ldlm_lock_addref_internal(lock, einfo->ei_mode);
ldlm_lock2handle(lock, lockh);
if (policy != NULL)
lock->l_policy_data = *policy;
LDLM_DEBUG(lock, "client-side enqueue START, flags %#llx", *flags);
lock->l_conn_export = exp;
lock->l_export = NULL;
lock->l_blocking_ast = einfo->ei_cb_bl;
lock->l_flags |= (*flags & (LDLM_FL_NO_LRU | LDLM_FL_EXCL |
LDLM_FL_ATOMIC_CB));
lock->l_activity = ktime_get_real_seconds();
ldlm_lock2desc(lock, &dlmreq->lock_desc);
dlmreq->lock_flags = ldlm_flags_to_wire(*flags);
dlmreq->lock_handle[0] = *lockh;
RETURN(0);
}
EXPORT_SYMBOL(ldlm_cli_lock_create_pack);
/**
* ldlm_cli_convert_req() - Client-side IBITS lock convert.
* @lock: lock which is being converted
* @flags: Flags related to lock operation
* @new_bits: MDS ibit Locks. (MDS inode access bits)
*
* Inform server that lock has been converted instead of canceling.
* Server finishes convert on own side and does reprocess to grant
* all related waiting locks.
*
* Since convert means only ibits downgrading, client doesn't need to
* wait for server reply to finish local converting process so this request
* is made asynchronous.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_convert_req(struct ldlm_lock *lock, __u32 *flags, __u64 new_bits)
{
struct ldlm_request *body;
struct ptlrpc_request *req;
struct obd_export *exp = lock->l_conn_export;
ENTRY;
LASSERT(exp != NULL);
/*
* this is better to check earlier and it is done so already,
* but this check is kept too as final one to issue an error
* if any new code will miss such check.
*/
if (!exp_connect_lock_convert(exp)) {
LDLM_ERROR(lock, "server doesn't support lock convert\n");
RETURN(-EPROTO);
}
if (lock->l_resource->lr_type != LDLM_IBITS) {
LDLM_ERROR(lock, "convert works with IBITS locks only.");
RETURN(-EINVAL);
}
LDLM_DEBUG(lock, "client-side convert");
req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
&RQF_LDLM_CONVERT, LUSTRE_DLM_VERSION,
LDLM_CONVERT);
if (IS_ERR(req))
RETURN(PTR_ERR(req));
body = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
body->lock_handle[0] = lock->l_remote_handle;
body->lock_desc.l_req_mode = lock->l_req_mode;
body->lock_desc.l_granted_mode = lock->l_granted_mode;
body->lock_desc.l_policy_data.l_inodebits.bits = new_bits;
body->lock_desc.l_policy_data.l_inodebits.cancel_bits =
MDS_INODELOCK_NONE;
body->lock_flags = ldlm_flags_to_wire(*flags);
body->lock_count = 1;
ptlrpc_request_set_replen(req);
/*
* Use cancel portals for convert as well as high-priority handling.
*/
req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL;
req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL;
ptlrpc_at_set_req_timeout(req);
if (exp->exp_obd->obd_svc_stats != NULL)
lprocfs_counter_incr(exp->exp_obd->obd_svc_stats,
LDLM_CONVERT - LDLM_FIRST_OPC);
ptlrpcd_add_req(req);
RETURN(0);
}
/**
* ldlm_cli_cancel_local() - Cancel locks locally.
* @lock: lock which is being cancel
*
* Returns:
* * %LDLM_FL_LOCAL_ONLY if there is no need for a CANCEL RPC to the server
* * %LDLM_FL_CANCELING otherwise;
* * %LDLM_FL_BL_AST if there is a need for a separate CANCEL RPC.
*/
static __u64 ldlm_cli_cancel_local(struct ldlm_lock *lock)
{
__u64 rc = LDLM_FL_LOCAL_ONLY;
ENTRY;
if (lock->l_conn_export) {
bool local_only;
LDLM_DEBUG(lock, "client-side cancel");
CFS_FAIL_TIMEOUT(OBD_FAIL_LDLM_PAUSE_CANCEL_LOCAL,
cfs_fail_val);
/* Set this flag to prevent others from getting new references*/
lock_res_and_lock(lock);
ldlm_set_cbpending(lock);
local_only = !!(lock->l_flags &
(LDLM_FL_LOCAL_ONLY|LDLM_FL_CANCEL_ON_BLOCK));
ldlm_cancel_callback(lock);
rc = (ldlm_is_bl_ast(lock)) ?
LDLM_FL_BL_AST : LDLM_FL_CANCELING;
unlock_res_and_lock(lock);
if (local_only) {
CDEBUG(D_DLMTRACE,
"not sending request (at caller's instruction)\n");
rc = LDLM_FL_LOCAL_ONLY;
}
ldlm_lock_cancel(lock);
} else {
if (ns_is_client(ldlm_lock_to_ns(lock))) {
LDLM_ERROR(lock, "Trying to cancel local lock");
LBUG();
}
LDLM_DEBUG(lock, "server-side local cancel");
ldlm_lock_cancel(lock);
ldlm_reprocess_all(lock->l_resource,
lock->l_policy_data.l_inodebits.bits);
}
RETURN(rc);
}
static inline int __ldlm_pack_lock(struct ldlm_lock *lock,
struct ldlm_request *dlm,
bool force)
{
LASSERT(lock->l_conn_export);
lock_res_and_lock(lock);
if (ldlm_is_ast_sent(lock) && !force) {
unlock_res_and_lock(lock);
return 0;
}
ldlm_set_ast_sent(lock);
unlock_res_and_lock(lock);
/* Pack the lock handle to the given request buffer. */
LDLM_DEBUG(lock, "packing");
dlm->lock_handle[dlm->lock_count++] = lock->l_remote_handle;
return 1;
}
/**
* ldlm_cancel_pack() - Pack @count locks in @lock and @head into ldlm_request
* buffer of the request @req.
* @req: PTLRPC request struct
* @lock: lock which is being packed
* @head: List of cancel @lock to pack
* @count: Number of @lock to pack
*
* Return @count of packed @lock
*/
static int ldlm_cancel_pack(struct ptlrpc_request *req, struct ldlm_lock *lock,
struct list_head *head, int count)
{
struct ldlm_request *dlm;
int max, packed = 0;
ENTRY;
dlm = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
LASSERT(dlm != NULL);
/* Check the room in the request buffer. */
max = req_capsule_get_size(&req->rq_pill, &RMF_DLM_REQ, RCL_CLIENT) -
sizeof(struct ldlm_request);
max /= sizeof(struct lustre_handle);
max += LDLM_LOCKREQ_HANDLES;
LASSERT(max >= dlm->lock_count + count);
/*
* XXX: it would be better to pack lock handles grouped by resource.
* so that the server cancel would call filter_lvbo_update() less
* frequently.
*/
if (lock) {
/*
* Individual lock is given only in ldlm_cli_cancel, likely
* handling blast RPC. It is not supposed to be packed in
* another RPC yet, but let's do not lose it here just in case,
* because we detect the HP by the first lock only now.
*/
packed = __ldlm_pack_lock(lock, dlm,
lock->l_flags & LDLM_FL_BL_AST);
count--;
}
if (count) { /* pack the list as well if given */
list_for_each_entry(lock, head, l_bl_ast) {
packed += __ldlm_pack_lock(lock, dlm, false);
if (!--count)
break;
}
}
CDEBUG(D_DLMTRACE, "%d locks packed\n", packed);
LASSERT(count == 0);
RETURN(packed);
}
/**
* ldlm_cli_cancel_req() - Prepare and send a batched cancel RPC.
* @exp: OBD export struct
* @lock: lock which is being canceled
* @head: List of @lock
* @count: Number of @lock to pack/batch
* @flags: Flags related to lock operation
*
* Prepare and send a batched cancel RPC. It will include @count lock
* handles of locks given in @lock and @cancels list.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_cancel_req(struct obd_export *exp, struct ldlm_lock *lock,
struct list_head *head, int count,
enum ldlm_cancel_flags flags)
{
struct ptlrpc_request *req = NULL;
struct obd_import *imp;
int free;
int rc = 0;
ENTRY;
LASSERT(exp != NULL);
LASSERT(count > 0);
LASSERT(head != NULL);
CFS_FAIL_TIMEOUT(OBD_FAIL_LDLM_PAUSE_CANCEL, cfs_fail_val);
if (CFS_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_RACE))
RETURN(count);
free = ldlm_format_handles_avail(class_exp2cliimp(exp),
&RQF_LDLM_CANCEL, RCL_CLIENT, 0);
if (count > free)
count = free;
while (1) {
imp = class_exp2cliimp(exp);
if (!imp || test_bit(IMPF_INVALID, imp->imp_flags)) {
CDEBUG(D_DLMTRACE,
"skipping cancel on invalid import %p\n", imp);
RETURN(count);
}
req = ptlrpc_request_alloc(imp, &RQF_LDLM_CANCEL);
if (req == NULL)
GOTO(out, rc = -ENOMEM);
req_capsule_filled_sizes(&req->rq_pill, RCL_CLIENT);
req_capsule_set_size(&req->rq_pill, &RMF_DLM_REQ, RCL_CLIENT,
ldlm_request_bufsize(count, LDLM_CANCEL));
rc = ptlrpc_request_pack(req, LUSTRE_DLM_VERSION, LDLM_CANCEL);
if (rc) {
ptlrpc_request_free(req);
GOTO(out, rc);
}
/*
* If OSP want cancel cross-MDT lock, let's not block it in
* recovery, otherwise the lock will not released, if
* the remote target is also in recovery, and it also need
* this lock, it might cause deadlock.
*/
if (exp_connect_flags(exp) & OBD_CONNECT_MDS_MDS &&
exp->exp_obd->obd_lu_dev != NULL &&
exp->exp_obd->obd_lu_dev->ld_site != NULL) {
struct lu_device *top_dev;
top_dev = exp->exp_obd->obd_lu_dev->ld_site->ls_top_dev;
if (top_dev != NULL &&
test_bit(OBDF_RECOVERING, top_dev->ld_obd->obd_flags))
req->rq_allow_replay = 1;
}
req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL;
req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL;
ptlrpc_at_set_req_timeout(req);
rc = ldlm_cancel_pack(req, lock, head, count);
if (rc == 0) {
ptlrpc_req_put(req);
GOTO(out, rc);
}
ptlrpc_request_set_replen(req);
if (flags & LCF_ASYNC) {
ptlrpcd_add_req(req);
GOTO(out, rc = 0);
}
rc = ptlrpc_queue_wait(req);
if (rc == LUSTRE_ESTALE) {
CDEBUG(D_DLMTRACE,
"client/server (nid %s) out of sync -- not fatal\n",
libcfs_nidstr(&req->rq_import->imp_connection->c_peer.nid));
rc = 0;
} else if (rc == -ETIMEDOUT && /* check there was no reconnect*/
req->rq_import_generation == imp->imp_generation) {
struct ldlm_lock *pos;
list_for_each_entry(pos, head, l_bl_ast) {
lock_res_and_lock(pos);
ldlm_clear_ast_sent(pos);
unlock_res_and_lock(pos);
}
if (lock) {
lock_res_and_lock(lock);
ldlm_clear_ast_sent(lock);
unlock_res_and_lock(lock);
}
ptlrpc_req_put(req);
continue;
} else if (rc != ELDLM_OK) {
/* -ESHUTDOWN is common on umount */
CDEBUG_LIMIT(rc == -ESHUTDOWN ? D_DLMTRACE : D_ERROR,
"Got rc %d from cancel RPC: canceling anyway\n",
rc);
break;
}
break;
}
ptlrpc_req_put(req);
EXIT;
out:
return rc ? : count;
}
/**
* ldlm_cli_update_pool() - Update client's OBD pool related fields with new
* SLV and Limit from @req.
* @req: PTLRPC request struct
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_update_pool(struct ptlrpc_request *req)
{
struct ldlm_namespace *ns;
struct obd_device *obd;
__u64 new_slv, ratio;
__u32 new_limit;
ENTRY;
if (unlikely(!req->rq_import || !req->rq_import->imp_obd ||
!imp_connect_lru_resize(req->rq_import)))
/* Do nothing for corner cases. */
RETURN(0);
/*
* In some cases RPC may contain SLV and limit zeroed out. This
* is the case when server does not support LRU resize feature.
* This is also possible in some recovery cases when server-side
* reqs have no reference to the OBD export and thus access to
* server-side namespace is not possible.
*/
if (lustre_msg_get_slv(req->rq_repmsg) == 0 ||
lustre_msg_get_limit(req->rq_repmsg) == 0) {
DEBUG_REQ(D_HA, req,
"Zero SLV or limit found (SLV=%llu, limit=%u)",
lustre_msg_get_slv(req->rq_repmsg),
lustre_msg_get_limit(req->rq_repmsg));
RETURN(0);
}
new_limit = lustre_msg_get_limit(req->rq_repmsg);
new_slv = lustre_msg_get_slv(req->rq_repmsg);
obd = req->rq_import->imp_obd;
read_lock(&obd->obd_pool_lock);
if (obd->obd_pool_slv == new_slv &&
obd->obd_pool_limit == new_limit) {
read_unlock(&obd->obd_pool_lock);
RETURN(0);
}
read_unlock(&obd->obd_pool_lock);
/*
* OBD device keeps the new pool attributes before they are handled by
* the pool.
*/
write_lock(&obd->obd_pool_lock);
obd->obd_pool_slv = new_slv;
obd->obd_pool_limit = new_limit;
write_unlock(&obd->obd_pool_lock);
/*
* Check if an urgent pool recalc is needed, let it to be a change of
* SLV on 10%. It is applicable to LRU resize enabled case only.
*/
ns = obd->obd_namespace;
if (!ns_connect_lru_resize(ns) ||
ldlm_pool_get_slv(&ns->ns_pool) < new_slv)
RETURN(0);
ratio = 100 * new_slv / ldlm_pool_get_slv(&ns->ns_pool);
if (100 - ratio >= ns->ns_recalc_pct &&
!test_bit(LDLM_NS_STOPPING, ns->ns_flags) &&
!test_bit(LDLM_NS_RPC_RECALC, ns->ns_flags)) {
bool recalc = false;
spin_lock(&ns->ns_lock);
if (!test_bit(LDLM_NS_STOPPING, ns->ns_flags) &&
!test_bit(LDLM_NS_RPC_RECALC, ns->ns_flags)) {
ldlm_namespace_get(ns);
recalc = true;
set_bit(LDLM_NS_RPC_RECALC, ns->ns_flags);
}
spin_unlock(&ns->ns_lock);
if (recalc)
ldlm_bl_to_thread_ns(ns);
}
RETURN(0);
}
int ldlm_cli_convert(struct ldlm_lock *lock,
enum ldlm_cancel_flags cancel_flags)
{
int rc = -EINVAL;
LASSERT(!lock->l_readers && !lock->l_writers);
LDLM_DEBUG(lock, "client lock convert START");
if (lock->l_resource->lr_type == LDLM_IBITS) {
lock_res_and_lock(lock);
do {
rc = ldlm_cli_inodebits_convert(lock, cancel_flags);
} while (rc == -EAGAIN);
unlock_res_and_lock(lock);
}
LDLM_DEBUG(lock, "client lock convert END");
RETURN(rc);
}
EXPORT_SYMBOL(ldlm_cli_convert);
/**
* ldlm_cli_cancel() - Client side lock cancel.
* @lockh:
* @flags:
*
* Lock must not have any readers or writers by this time.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_cancel(const struct lustre_handle *lockh,
enum ldlm_cancel_flags flags)
{
struct obd_export *exp;
int avail, count = 1;
enum ldlm_lru_flags lru_flags = 0;
enum ldlm_cancel_flags cancel_flags = 0;
__u64 rc = 0;
struct ldlm_namespace *ns;
struct ldlm_lock *lock;
LIST_HEAD(cancels);
ENTRY;
lock = ldlm_handle2lock_long(lockh, 0);
if (lock == NULL) {
LDLM_DEBUG_NOLOCK("lock is already being destroyed");
RETURN(0);
}
lock_res_and_lock(lock);
LASSERT(!ldlm_is_converting(lock));
if (ldlm_is_bl_ast(lock)) {
if (ldlm_is_ast_sent(lock)) {
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
RETURN(0);
}
} else if (ldlm_is_canceling(lock)) {
/* Lock is being canceled and the caller doesn't want to wait */
if (flags & LCF_ASYNC) {
unlock_res_and_lock(lock);
} else {
unlock_res_and_lock(lock);
wait_event_idle(lock->l_waitq, is_bl_done(lock));
}
ldlm_lock_put(lock);
RETURN(0);
}
ldlm_set_canceling(lock);
unlock_res_and_lock(lock);
if (flags & LCF_LOCAL)
CFS_FAIL_TIMEOUT(OBD_FAIL_LDLM_LOCAL_CANCEL_PAUSE,
cfs_fail_val);
rc = ldlm_cli_cancel_local(lock);
if (rc == LDLM_FL_LOCAL_ONLY || flags & LCF_LOCAL) {
ldlm_lock_put(lock);
RETURN(0);
} else if (rc == LDLM_FL_BL_AST) {
/* BL_AST lock must not wait. */
lru_flags |= LDLM_LRU_FLAG_NO_WAIT;
cancel_flags |= LCF_BL_AST;
}
exp = lock->l_conn_export;
/*
* This is a LDLM_CANCEL RPC which goes to canceld portal,
* so we can cancel other LRU locks here and send them all
* as one LDLM_CANCEL RPC.
*/
if (exp_connect_cancelset(exp)) {
avail = ldlm_format_handles_avail(class_exp2cliimp(exp),
&RQF_LDLM_CANCEL,
RCL_CLIENT, 0);
LASSERT(avail > 0);
ns = ldlm_lock_to_ns(lock);
count += ldlm_cancel_lru_local(ns, &cancels, 0, avail - 1,
cancel_flags, lru_flags);
}
ldlm_cli_cancel_list(&cancels, count, lock, NULL, flags);
RETURN(0);
}
EXPORT_SYMBOL(ldlm_cli_cancel);
/**
* ldlm_cli_cancel_list_local() - Locally cancel up to @count locks in list of
* @cancels.
* @cancels: List of cancel locks
* @count: Number of lock to cancel
* @cancel_flags: Cancel flags
*
* Return the number of cancelled locks.
*/
int ldlm_cli_cancel_list_local(struct list_head *cancels, int count,
enum ldlm_cancel_flags cancel_flags)
{
LIST_HEAD(head);
struct ldlm_lock *lock, *next;
int left = 0, bl_ast = 0;
__u64 rc;
left = count;
list_for_each_entry_safe(lock, next, cancels, l_bl_ast) {
if (left-- == 0)
break;
if (cancel_flags & LCF_LOCAL) {
rc = LDLM_FL_LOCAL_ONLY;
ldlm_lock_cancel(lock);
} else {
rc = ldlm_cli_cancel_local(lock);
}
/*
* Until we have compound requests and can send LDLM_CANCEL
* requests batched with generic RPCs, we need to send cancels
* with the LDLM_FL_BL_AST flag in a separate RPC from
* the one being generated now.
*/
if (!(cancel_flags & LCF_BL_AST) && (rc == LDLM_FL_BL_AST)) {
LDLM_DEBUG(lock, "Cancel lock separately");
list_move(&lock->l_bl_ast, &head);
bl_ast++;
continue;
}
if (rc == LDLM_FL_LOCAL_ONLY) {
/* CANCEL RPC should not be sent to server. */
list_del_init(&lock->l_bl_ast);
ldlm_lock_put(lock);
count--;
}
}
if (bl_ast > 0) {
count -= bl_ast;
ldlm_cli_cancel_list(&head, bl_ast, NULL, NULL, cancel_flags);
}
RETURN(count);
}
/**
* ldlm_cancel_no_wait_policy() - Cancel as many locks as possible w/o sending
* any RPCs
* @ns: Pointer to the LDLM namespace
* @lock: LDLM lock to cancel
* @added: Keep @lock in LRU only if @added < @min
* @min: Minimum number to locks to cancel
*
* Cancel as many locks as possible w/o sending any RPCs (e.g. to write back
* dirty data, to close a file, ...) or waiting for any RPCs in-flight (e.g.
* readahead requests, ...)
*
* Return LDLM_POLICY based on type and cancel status
*/
static enum ldlm_policy_res
ldlm_cancel_no_wait_policy(struct ldlm_namespace *ns, struct ldlm_lock *lock,
int added, int min)
{
enum ldlm_policy_res result = LDLM_POLICY_CANCEL_LOCK;
/*
* don't check @added & @min since we want to process all locks
* from unused list.
* It's fine to not take lock to access lock->l_resource since
* the lock has already been granted so it won't change.
*/
switch (lock->l_resource->lr_type) {
case LDLM_EXTENT:
case LDLM_IBITS:
if (ns->ns_cancel != NULL && ns->ns_cancel(lock) != 0)
break;
fallthrough;
default:
result = LDLM_POLICY_SKIP_LOCK;
break;
}
RETURN(result);
}
/**
* ldlm_cancel_lrur_policy() - Callback function for LRU-resize policy
* @ns: Pointer to the LDLM namespace
* @lock: LDLM lock to cancel
* @added: Keep @lock in LRU only if @added < @min
* @min: Minimum number to locks to cancel
*
* Callback function for LRU-resize policy. Decides whether to keep
* @lock in LRU for @added in current scan and @min number of locks
* to be preferably canceled.
*
* Return:
* * %LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
* * %LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
*/
static enum ldlm_policy_res ldlm_cancel_lrur_policy(struct ldlm_namespace *ns,
struct ldlm_lock *lock,
int added, int min)
{
ktime_t cur = ktime_get();
struct ldlm_pool *pl = &ns->ns_pool;
u64 slv, lvf, lv;
s64 la;
if (added < min)
return LDLM_POLICY_CANCEL_LOCK;
/*
* Despite of the LV, It doesn't make sense to keep the lock which
* is unused for ns_max_age time.
*/
if (ktime_after(cur, ktime_add(lock->l_last_used, ns->ns_max_age)))
return LDLM_POLICY_CANCEL_LOCK;
slv = ldlm_pool_get_slv(pl);
lvf = ldlm_pool_get_lvf(pl);
la = div_u64(ktime_to_ns(ktime_sub(cur, lock->l_last_used)),
NSEC_PER_SEC);
lv = lvf * la * ns->ns_nr_unused >> 8;
/* Inform pool about current CLV to see it via debugfs. */
ldlm_pool_set_clv(pl, lv);
/*
* Stop when SLV is not yet come from server or lv is smaller than
* it is.
*/
if (slv == 0 || lv < slv)
return LDLM_POLICY_KEEP_LOCK;
return LDLM_POLICY_CANCEL_LOCK;
}
static enum ldlm_policy_res
ldlm_cancel_lrur_no_wait_policy(struct ldlm_namespace *ns,
struct ldlm_lock *lock,
int added, int min)
{
enum ldlm_policy_res result;
result = ldlm_cancel_lrur_policy(ns, lock, added, min);
if (result == LDLM_POLICY_KEEP_LOCK)
return result;
return ldlm_cancel_no_wait_policy(ns, lock, added, min);
}
/**
* ldlm_cancel_aged_policy() - Callback function for aged policy.
* @ns: Pointer to the LDLM namespace
* @lock: LDLM lock to cancel
* @added: Keep @lock in LRU only if @added < @min
* @min: Minimum number to locks to cancel
*
* Callback function for aged policy. Decides whether to keep
* @lock in LRU for @added in current scan and @min number of locks
* to be preferably canceled.
*
* Return:
* * %LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
* * %LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
*/
static enum ldlm_policy_res ldlm_cancel_aged_policy(struct ldlm_namespace *ns,
struct ldlm_lock *lock,
int added, int min)
{
if ((added >= min) &&
ktime_before(ktime_get(),
ktime_add(lock->l_last_used, ns->ns_max_age)))
return LDLM_POLICY_KEEP_LOCK;
return LDLM_POLICY_CANCEL_LOCK;
}
static enum ldlm_policy_res
ldlm_cancel_aged_no_wait_policy(struct ldlm_namespace *ns,
struct ldlm_lock *lock,
int added, int min)
{
enum ldlm_policy_res result;
result = ldlm_cancel_aged_policy(ns, lock, added, min);
if (result == LDLM_POLICY_KEEP_LOCK)
return result;
return ldlm_cancel_no_wait_policy(ns, lock, added, min);
}
typedef enum ldlm_policy_res
(*ldlm_cancel_lru_policy_t)(struct ldlm_namespace *ns, struct ldlm_lock *lock,
int added, int min);
static ldlm_cancel_lru_policy_t
ldlm_cancel_lru_policy(struct ldlm_namespace *ns, enum ldlm_lru_flags lru_flags)
{
if (ns_connect_lru_resize(ns)) {
if (lru_flags & LDLM_LRU_FLAG_NO_WAIT)
return ldlm_cancel_lrur_no_wait_policy;
else
return ldlm_cancel_lrur_policy;
} else {
if (lru_flags & LDLM_LRU_FLAG_NO_WAIT)
return ldlm_cancel_aged_no_wait_policy;
else
return ldlm_cancel_aged_policy;
}
}
/**
* ldlm_prepare_lru_list() - Scan LRU list and identify locks for cancellation
* @ns: Pointer to the LDLM namespace
* @cancels: List of cancel locks
* @min: Minimum number of locks to cancel
* @max: Maximum number of locks to cancel
* @batch: Chunck in wich to process locks
* @lru_flags: Cancel lru flag (indicates we cancel aged locks)
*
* - Free space in LRU for @min new locks, redundant unused locks are canceled
* locally;
* - also cancel locally unused aged locks;
* - do not cancel more than @max locks;
* - if some locks are cancelled, try to cancel at least @batch locks
* - GET the found locks and add them into the @cancels list.
*
* A client lock can be added to the l_bl_ast list only when it is marked
* LDLM_FL_CANCELING. Otherwise, somebody is already doing CANCEL.
* There are the following use cases:
* ldlm_cancel_resource_local(), ldlm_cancel_lru_local() and
* ldlm_cli_cancel(), which check and set this flag properly. As any
* attempt to cancel a lock rely on this flag, l_bl_ast list is accessed
* later without any special locking.
*
* Locks are cancelled according to the LRU resize policy (SLV from server)
* if LRU resize is enabled; otherwise, the "aged policy" is used;
*
* ----------
* LRU flags:
* ----------
*
* flags & LDLM_LRU_FLAG_NO_WAIT - cancel locks w/o sending any RPCs or waiting
* for any outstanding RPC to complete.
*
* flags & LDLM_CANCEL_CLEANUP - when cancelling read locks, do not check for
* other read locks covering the same pages, just
* discard those pages.
*
* Return:
* * total number of locks that was added to cancel list
* * %negative on failure
*/
static int ldlm_prepare_lru_list(struct ldlm_namespace *ns,
struct list_head *cancels,
int min, int max, int batch,
enum ldlm_lru_flags lru_flags)
{
ldlm_cancel_lru_policy_t pf;
int added = 0;
int no_wait = lru_flags & LDLM_LRU_FLAG_NO_WAIT;
ENTRY;
/*
* Let only 1 thread to proceed. However, not for those which have the
* @max limit given (ELC), as LRU may be left not cleaned up in full.
*/
if (max == 0) {
if (test_and_set_bit(LDLM_NS_LRU_CANCEL, ns->ns_flags))
RETURN(0);
} else if (test_bit(LDLM_NS_LRU_CANCEL, ns->ns_flags))
RETURN(0);
LASSERT(ergo(max, min <= max));
/* No sense to give @batch for ELC */
LASSERT(ergo(max, batch == 0));
if (!ns_connect_lru_resize(ns))
min = max_t(int, min, ns->ns_nr_unused - ns->ns_max_unused);
/* If at least 1 lock is to be cancelled, cancel at least @batch locks */
if (min && min < batch)
min = batch;
pf = ldlm_cancel_lru_policy(ns, lru_flags);
LASSERT(pf != NULL);
spin_lock(&ns->ns_lock);
if (ns->ns_lock_cache_ops &&
ns->ns_lock_cache_ops->llco_try_batch_demote_locks) {
int batch_size = (min == INT_MAX) ? INT_MAX :
LDLM_LFRU_PRIV_PER_ROUND_LIMIT;
ns->ns_lock_cache_ops->llco_try_batch_demote_locks(ns,
batch_size);
}
spin_unlock(&ns->ns_lock);
/* For any flags, stop scanning if @max is reached. */
while (!list_empty(&ns->ns_unused_normal_list) &&
(max == 0 || added < max)) {
struct ldlm_lock *lock;
struct list_head *item, *next;
enum ldlm_policy_res result;
ktime_t last_use = ktime_set(0, 0);
spin_lock(&ns->ns_lock);
item = no_wait ? ns->ns_last_pos :
&ns->ns_unused_normal_list;
for (item = item->next, next = item->next;
item != &ns->ns_unused_normal_list;
item = next, next = item->next) {
lock = list_entry(item, struct ldlm_lock, l_lru);
/* No locks which got blocking requests. */
LASSERT(!ldlm_is_bl_ast(lock));
if (!ldlm_is_canceling(lock))
break;
/*
* Somebody is already doing CANCEL. No need for this
* lock in LRU, do not traverse it again.
*/
ldlm_lock_remove_from_lru_nolock(lock);
}
if (item == &ns->ns_unused_normal_list) {
spin_unlock(&ns->ns_lock);
break;
}
last_use = lock->l_last_used;
ldlm_lock_get(lock);
spin_unlock(&ns->ns_lock);
/*
* Pass the lock through the policy filter and see if it
* should stay in LRU.
*
* Even for shrinker policy we stop scanning if
* we find a lock that should stay in the cache.
* We should take into account lock age anyway
* as a new lock is a valuable resource even if
* it has a low weight.
*
* That is, for shrinker policy we drop only
* old locks, but additionally choose them by
* their weight. Big extent locks will stay in
* the cache.
*/
result = pf(ns, lock, added, min);
if (result == LDLM_POLICY_KEEP_LOCK) {
ldlm_lock_put(lock);
break;
}
if (result == LDLM_POLICY_SKIP_LOCK) {
if (no_wait) {
spin_lock(&ns->ns_lock);
if (!list_empty(&lock->l_lru) &&
lock->l_lru.prev == ns->ns_last_pos)
ns->ns_last_pos = &lock->l_lru;
spin_unlock(&ns->ns_lock);
}
ldlm_lock_put(lock);
continue;
}
lock_res_and_lock(lock);
/* Check flags again under the lock. */
if (ldlm_is_canceling(lock) ||
ldlm_lock_remove_from_lru_check(lock, last_use, false) ==
0) {
/*
* Another thread is removing lock from LRU, or
* somebody is already doing CANCEL, or there
* is a blocking request which will send cancel
* by itself, or the lock is no longer unused or
* the lock has been used since the pf() call and
* pages could be put under it.
*/
unlock_res_and_lock(lock);
ldlm_lock_put(lock);
continue;
}
LASSERT(!lock->l_readers && !lock->l_writers);
/*
* If we have chosen to cancel this lock voluntarily, we
* better send cancel notification to server, so that it
* frees appropriate state. This might lead to a race
* where while we are doing cancel here, server is also
* silently cancelling this lock.
*/
ldlm_clear_cancel_on_block(lock);
/*
* Setting the CBPENDING flag is a little misleading,
* but prevents an important race; namely, once
* CBPENDING is set, the lock can accumulate no more
* readers/writers. Since readers and writers are
* already zero here, ldlm_lock_decref() won't see
* this flag and call l_blocking_ast
*/
lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_CANCELING;
if ((lru_flags & LDLM_LRU_FLAG_CLEANUP) &&
(lock->l_resource->lr_type == LDLM_EXTENT ||
ldlm_has_dom(lock)) && lock->l_granted_mode == LCK_PR)
ldlm_set_discard_data(lock);
/*
* We can't re-add to l_lru as it confuses the
* refcounting in ldlm_lock_remove_from_lru() if an AST
* arrives after we drop lr_lock below. We use l_bl_ast
* and can't use l_pending_chain as it is used both on
* server and client nevertheless b=5666 says it is
* used only on server
*/
LASSERT(list_empty(&lock->l_bl_ast));
list_add(&lock->l_bl_ast, cancels);
unlock_res_and_lock(lock);
added++;
/* Once a lock added, batch the requested amount */
if (min == 0)
min = batch;
}
if (max == 0)
clear_bit(LDLM_NS_LRU_CANCEL, ns->ns_flags);
RETURN(added);
}
int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels,
int min, int max,
enum ldlm_cancel_flags cancel_flags,
enum ldlm_lru_flags lru_flags)
{
int added;
added = ldlm_prepare_lru_list(ns, cancels, min, max, 0, lru_flags);
if (added <= 0)
return added;
return ldlm_cli_cancel_list_local(cancels, added, cancel_flags);
}
/**
* ldlm_cancel_lru() - Cancel at least @min locks from given namespace LRU.
* @ns: Pointer to the LDLM namespace
* @min: Minimum number to locks to cancel
* @cancel_flags: Cancel flags
* @lru_flags: Cancel lru flag (indicates we cancel aged locks)
*
* When called with LCF_ASYNC the blocking callback will be handled
* in a thread and this function will return after the thread has been
* asked to call the callback. When called with LCF_ASYNC the blocking
* callback will be performed in this function.
*
* Return:
* * %0 then the lock referenced as @lock is queued instead.
* * %count of locks for cancels for later processing
*/
int ldlm_cancel_lru(struct ldlm_namespace *ns, int min,
enum ldlm_cancel_flags cancel_flags,
enum ldlm_lru_flags lru_flags)
{
LIST_HEAD(cancels);
int count, rc;
ENTRY;
/*
* Just prepare the list of locks, do not actually cancel them yet.
* Locks are cancelled later in a separate thread.
*/
count = ldlm_prepare_lru_list(ns, &cancels, min, 0,
ns->ns_cancel_batch, lru_flags);
rc = ldlm_bl_to_thread_list(ns, NULL, &cancels, count, cancel_flags);
if (rc == 0)
RETURN(count);
RETURN(0);
}
/**
* ldlm_cancel_resource_local() - Find & cancel locally unused locks.
* @res: LDLM resource
* @cancels: List of cancel locks
* @policy: LDLM policy data
* @mode: Lock types
* @lock_flags: Flags related to lock operation
* @cancel_flags: Cancel flags
* @opaque: data passed to callback functions
*
* Find and cancel locally unused locks found on resource, matched to the
* given policy, mode. GET the found locks and add them into the \a cancels
* list.
*
* Return the number of cancelled locks.
*/
int ldlm_cancel_resource_local(struct ldlm_resource *res,
struct list_head *cancels,
union ldlm_policy_data *policy,
enum ldlm_mode mode, __u64 lock_flags,
enum ldlm_cancel_flags cancel_flags,
void *opaque)
{
struct ldlm_lock *lock;
int count = 0;
ENTRY;
lock_res(res);
list_for_each_entry(lock, &res->lr_granted, l_res_link) {
if (opaque != NULL && lock->l_ast_data != opaque) {
LDLM_ERROR(lock, "data %p doesn't match opaque %p",
lock->l_ast_data, opaque);
continue;
}
if (lock->l_readers || lock->l_writers)
continue;
/*
* If somebody is already doing CANCEL, or blocking AST came
* then skip this lock.
*/
if (ldlm_is_bl_ast(lock) || ldlm_is_canceling(lock))
continue;
if (lockmode_compat(lock->l_granted_mode, mode))
continue;
/*
* If policy is given and this is IBITS lock, add to list only
* those locks that match by policy.
*/
if (policy && (lock->l_resource->lr_type == LDLM_IBITS)) {
if (!(lock->l_policy_data.l_inodebits.bits &
policy->l_inodebits.bits))
continue;
/* Skip locks with DoM bit if it is not set in policy
* to don't flush data by side-bits. Lock convert will
* drop those bits separately.
*/
if (ldlm_has_dom(lock) &&
!(policy->l_inodebits.bits & MDS_INODELOCK_DOM))
continue;
}
/* See CBPENDING comment in ldlm_cancel_lru */
lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_CANCELING |
lock_flags;
LASSERT(list_empty(&lock->l_bl_ast));
list_add(&lock->l_bl_ast, cancels);
ldlm_lock_get(lock);
count++;
}
unlock_res(res);
RETURN(ldlm_cli_cancel_list_local(cancels, count, cancel_flags));
}
EXPORT_SYMBOL(ldlm_cancel_resource_local);
/**
* ldlm_cli_cancel_list() - Cancel client-side locks and send/prepare cancel
* RPCs to the server.
* @cancels: List of cancel locks
* @count: Number of lock to cancel
* @primary: Destroy @count of locks at the end, starting with the @primary
* @req: PTLRPC request
* @flags: Lock operation flags
*
* Locks passed as a @cancels list of locks or/and as a @primary lock.
*
* @count must not be larger than the total amount of passed locks in
* @primary and @cancels. Thus, it includes the @primary (if passed), but
* may not include all the locks in @cancels (if passed).
*
* If @req is NULL, a new CANCEL RPC is created and sent with @count lh
* packed into it, starting with the @primary one.
*
* If EARLY_CANCEL is not supported, @count of CANCEL RPCs is created and
* sent with one lh in each request.
*
* If @req is not NULL, @count of lh are just need to be placed into the
* RMF_DLM_REQ buffer of the given req.
*
* Destroy @count of locks at the end, starting with the @primary one.
*
* Return %0 always
*/
int ldlm_cli_cancel_list(struct list_head *cancels, int count,
struct ldlm_lock *primary,
struct ptlrpc_request *req,
enum ldlm_cancel_flags flags)
{
struct ldlm_lock *lock = primary;
struct obd_export *export;
int res = 0;
ENTRY;
if (count == 0)
RETURN(0);
LASSERT(primary || !list_empty(cancels));
if (lock == NULL)
lock = list_first_entry(cancels, struct ldlm_lock, l_bl_ast);
export = lock->l_conn_export;
LASSERT(export != NULL);
/*
* XXX: requests (both batched and not) could be sent in parallel.
* Usually it is enough to have just 1 RPC, but it is possible that
* there are too many locks to be cancelled in LRU or on a resource.
* It would also speed up the case when the server does not support
* the feature.
*/
while (count > 0) {
LASSERT(primary || !list_empty(cancels));
if (exp_connect_cancelset(export)) {
if (req)
res = ldlm_cancel_pack(req, primary,
cancels, count);
else
res = ldlm_cli_cancel_req(export,
primary, cancels,
count, flags);
} else {
res = ldlm_cli_cancel_req(export, primary,
cancels, 1, flags);
}
if (res < 0) {
CDEBUG_LIMIT(res == -ESHUTDOWN ? D_DLMTRACE : D_ERROR,
"ldlm_cli_cancel_list: %d\n", res);
res = count;
}
count -= res;
if (primary && res) {
ldlm_lock_put(primary);
primary = NULL;
res--;
}
ldlm_lock_list_put(cancels, l_bl_ast, res);
}
LASSERT(count == 0);
RETURN(0);
}
EXPORT_SYMBOL(ldlm_cli_cancel_list);
/**
* ldlm_cli_cancel_unused_resource() - Cancel all locks on a resource that
* have 0 readers/writers.
* @ns: Pointer to the LDLM namespace
* @res_id: The resource name for the DLM request
* @policy: LDLM policy data
* @mode: Lock types
* @flags: Cancel flags
* @opaque: data passed to callback functions
*
* If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying
* to notify the server.
*
* Return %0 always
*/
int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
const struct ldlm_res_id *res_id,
union ldlm_policy_data *policy,
enum ldlm_mode mode,
enum ldlm_cancel_flags flags, void *opaque)
{
struct ldlm_resource *res;
LIST_HEAD(cancels);
int count;
int rc;
ENTRY;
res = ldlm_resource_get(ns, res_id, 0, 0);
if (IS_ERR(res)) {
/* This is not a problem. */
CDEBUG(D_INFO, "No resource %llu\n", res_id->name[0]);
RETURN(0);
}
count = ldlm_cancel_resource_local(res, &cancels, policy, mode,
0, flags, opaque);
rc = ldlm_cli_cancel_list(&cancels, count, NULL, NULL, flags);
if (rc != ELDLM_OK)
CERROR("canceling unused lock "DLDLMRES": rc = %d\n",
PLDLMRES(res), rc);
ldlm_resource_putref(res);
RETURN(0);
}
EXPORT_SYMBOL(ldlm_cli_cancel_unused_resource);
struct ldlm_cli_cancel_arg {
int lc_flags;
void *lc_opaque;
};
static int
ldlm_cli_hash_cancel_unused(struct cfs_hash *hs, struct cfs_hash_bd *bd,
struct hlist_node *hnode, void *arg)
{
struct ldlm_resource *res = cfs_hash_object(hs, hnode);
struct ldlm_cli_cancel_arg *lc = arg;
ldlm_cli_cancel_unused_resource(ldlm_res_to_ns(res), &res->lr_name,
NULL, LCK_MODE_MIN, lc->lc_flags,
lc->lc_opaque);
/* must return 0 for hash iteration */
return 0;
}
/**
* ldlm_cli_cancel_unused() - Cancel all locks on a namespace
* @ns: Pointer to the LDLM namespace
* @res_id: The resource name for the DLM request
* @flags: Cancel flags
* @opaque: data passed to callback functions
*
* Cancel all locks on a namespace (or a specific resource, if given)
* that have 0 readers/writers.
*
* If flags & LCF_LOCAL, throw the locks away without trying
* to notify the server.
*
* Return:
* * %0 on success
* * %negative on failure
*/
int ldlm_cli_cancel_unused(struct ldlm_namespace *ns,
const struct ldlm_res_id *res_id,
enum ldlm_cancel_flags flags, void *opaque)
{
struct ldlm_cli_cancel_arg arg = {
.lc_flags = flags,
.lc_opaque = opaque,
};
ENTRY;
if (ns == NULL)
RETURN(ELDLM_OK);
if (res_id != NULL) {
RETURN(ldlm_cli_cancel_unused_resource(ns, res_id, NULL,
LCK_MODE_MIN, flags,
opaque));
} else {
cfs_hash_for_each_nolock(ns->ns_rs_hash,
ldlm_cli_hash_cancel_unused, &arg, 0);
RETURN(ELDLM_OK);
}
}
/* Lock iterators. */
int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
void *closure)
{
struct ldlm_lock *tmp;
struct ldlm_lock *lock;
int rc = LDLM_ITER_CONTINUE;
ENTRY;
if (!res)
RETURN(LDLM_ITER_CONTINUE);
lock_res(res);
list_for_each_entry_safe(lock, tmp, &res->lr_granted, l_res_link) {
if (iter(lock, closure) == LDLM_ITER_STOP)
GOTO(out, rc = LDLM_ITER_STOP);
}
list_for_each_entry_safe(lock, tmp, &res->lr_waiting, l_res_link) {
if (iter(lock, closure) == LDLM_ITER_STOP)
GOTO(out, rc = LDLM_ITER_STOP);
}
out:
unlock_res(res);
RETURN(rc);
}
struct iter_helper_data {
ldlm_iterator_t iter;
void *closure;
};
static int ldlm_iter_helper(struct ldlm_lock *lock, void *closure)
{
struct iter_helper_data *helper = closure;
return helper->iter(lock, helper->closure);
}
static int ldlm_res_iter_helper(struct cfs_hash *hs, struct cfs_hash_bd *bd,
struct hlist_node *hnode, void *arg)
{
struct ldlm_resource *res = cfs_hash_object(hs, hnode);
return ldlm_resource_foreach(res, ldlm_iter_helper, arg) ==
LDLM_ITER_STOP;
}
void ldlm_namespace_foreach(struct ldlm_namespace *ns,
ldlm_iterator_t iter, void *closure)
{
struct iter_helper_data helper = { .iter = iter, .closure = closure };
cfs_hash_for_each_nolock(ns->ns_rs_hash,
ldlm_res_iter_helper, &helper, 0);
}
/*
* ldlm_resource_iterate() - non-blocking function to manipulate a lock whose
* cb_data is being put away.
* @ns: Pointer to the LDLM namespace
* @res_id: The resource name for the DLM request
* @iter: ldlm iterator
* @data: Additional data
*
* Return:
* * %0 find no resource
* * %positive must be LDLM_ITER_STOP/LDLM_ITER_CONTINUE.
* * %negative on errors
*/
int ldlm_resource_iterate(struct ldlm_namespace *ns,
const struct ldlm_res_id *res_id,
ldlm_iterator_t iter, void *data)
{
struct ldlm_resource *res;
int rc;
ENTRY;
LASSERTF(ns != NULL, "must pass in namespace\n");
res = ldlm_resource_get(ns, res_id, 0, 0);
if (IS_ERR(res))
RETURN(0);
rc = ldlm_resource_foreach(res, iter, data);
ldlm_resource_putref(res);
RETURN(rc);
}
EXPORT_SYMBOL(ldlm_resource_iterate);
/* Lock replay */
static int ldlm_chain_lock_for_replay(struct ldlm_lock *lock, void *closure)
{
struct list_head *list = closure;
/* we use l_pending_chain here, because it's unused on clients. */
LASSERTF(list_empty(&lock->l_pending_chain),
"lock %px next %px prev %px\n",
lock, &lock->l_pending_chain.next,
&lock->l_pending_chain.prev);
/*
* b=9573: don't replay locks left after eviction, or
* b=17614: locks being actively cancelled. Get a reference
* on a lock so that it does not disapear under us (e.g. due to cancel)
*/
if (!(lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_BL_DONE))) {
list_add(&lock->l_pending_chain, list);
ldlm_lock_get(lock);
}
return LDLM_ITER_CONTINUE;
}
static int replay_lock_interpret(const struct lu_env *env,
struct ptlrpc_request *req, void *args, int rc)
{
struct ldlm_async_args *aa = args;
struct ldlm_lock *lock;
struct ldlm_reply *reply;
struct obd_export *exp;
ENTRY;
atomic_dec(&req->rq_import->imp_replay_inflight);
wake_up(&req->rq_import->imp_replay_waitq);
if (rc != ELDLM_OK)
GOTO(out, rc);
reply = req_capsule_server_get(&req->rq_pill, &RMF_DLM_REP);
if (reply == NULL)
GOTO(out, rc = -EPROTO);
lock = ldlm_handle2lock(&aa->lock_handle);
if (!lock) {
CERROR("received replay ack for unknown local cookie %#llx remote cookie %#llx from server %s id %s\n",
aa->lock_handle.cookie, reply->lock_handle.cookie,
req->rq_export->exp_client_uuid.uuid,
libcfs_idstr(&req->rq_peer));
GOTO(out, rc = -ESTALE);
}
/* Key change rehash lock in per-export hash with new key */
exp = req->rq_export;
if (exp && exp->exp_lock_hash) {
/*
* In the function below, .hs_keycmp resolves to
* ldlm_export_lock_keycmp()
*/
cfs_hash_rehash_key(exp->exp_lock_hash,
&lock->l_remote_handle,
&reply->lock_handle,
&lock->l_exp_hash);
} else {
lock->l_remote_handle = reply->lock_handle;
}
LDLM_DEBUG(lock, "replayed lock:");
ptlrpc_import_recovery_state_machine(req->rq_import);
ldlm_lock_put(lock);
out:
if (rc != ELDLM_OK || CFS_FAIL_CHECK(OBD_FAIL_PTLRPC_FAIL_REPLAY))
ptlrpc_connect_import(req->rq_import);
RETURN(rc);
}
static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
{
struct ptlrpc_request *req;
struct ldlm_async_args *aa;
struct ldlm_request *body;
int flags;
ENTRY;
/* b=11974: Do not replay a lock which is actively being canceled */
if (ldlm_is_bl_done(lock)) {
LDLM_DEBUG(lock, "Not replaying canceled lock:");
RETURN(0);
}
/*
* If this is reply-less callback lock, we cannot replay it, since
* server might have long dropped it, but notification of that event was
* lost by network. (and server granted conflicting lock already)
*/
if (ldlm_is_cancel_on_block(lock)) {
LDLM_DEBUG(lock, "Not replaying reply-less lock:");
ldlm_lock_cancel(lock);
RETURN(0);
}
/*
* If granted mode matches the requested mode, this lock is granted.
*
* If we haven't been granted anything and are on a resource list,
* then we're blocked/waiting.
*
* If we haven't been granted anything and we're NOT on a resource list,
* then we haven't got a reply yet and don't have a known disposition.
* This happens whenever a lock enqueue is the request that triggers
* recovery.
*/
if (ldlm_is_granted(lock))
flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_GRANTED;
else if (!list_empty(&lock->l_res_link))
flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_WAIT;
else
flags = LDLM_FL_REPLAY;
req = ptlrpc_request_alloc_pack(imp, &RQF_LDLM_ENQUEUE,
LUSTRE_DLM_VERSION, LDLM_ENQUEUE);
if (IS_ERR(req))
RETURN(PTR_ERR(req));
/* We're part of recovery, so don't wait for it. */
req->rq_send_state = LUSTRE_IMP_REPLAY_LOCKS;
/* If the state changed while we were prepared, don't wait */
req->rq_no_delay = 1;
body = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
ldlm_lock2desc(lock, &body->lock_desc);
body->lock_flags = ldlm_flags_to_wire(flags);
ldlm_lock2handle(lock, &body->lock_handle[0]);
if (lock->l_lvb_len > 0)
req_capsule_extend(&req->rq_pill, &RQF_LDLM_ENQUEUE_LVB);
req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
lock->l_lvb_len);
ptlrpc_request_set_replen(req);
/*
* notify the server we've replayed all requests.
* also, we mark the request to be put on a dedicated
* queue to be processed after all request replayes.
* b=6063
*/
lustre_msg_set_flags(req->rq_reqmsg, MSG_REQ_REPLAY_DONE);
LDLM_DEBUG(lock, "replaying lock:");
atomic_inc(&imp->imp_replay_inflight);
aa = ptlrpc_req_async_args(aa, req);
aa->lock_handle = body->lock_handle[0];
req->rq_interpret_reply = replay_lock_interpret;
ptlrpcd_add_req(req);
RETURN(0);
}
/*
* Cancel as many unused locks as possible before replay. since we are
* in recovery, we can't wait for any outstanding RPCs to send any RPC
* to the server.
*
* Called only in recovery before replaying locks. there is no need to
* replay locks that are unused. since the clients may hold thousands of
* cached unused locks, dropping the unused locks can greatly reduce the
* load on the servers at recovery time.
*/
static void ldlm_cancel_unused_locks_for_replay(struct ldlm_namespace *ns)
{
int canceled;
LIST_HEAD(cancels);
CDEBUG(D_DLMTRACE,
"Dropping as many unused locks as possible before replay for namespace %s (%d)\n",
ldlm_ns_name(ns), ns->ns_nr_unused);
CFS_FAIL_TIMEOUT(OBD_FAIL_LDLM_REPLAY_PAUSE, cfs_fail_val);
/*
* We don't need to care whether or not LRU resize is enabled
* because the LDLM_LRU_FLAG_NO_WAIT policy doesn't use the
* count parameter
*/
canceled = ldlm_cancel_lru_local(ns, &cancels, ns->ns_nr_unused, 0,
LCF_LOCAL, LDLM_LRU_FLAG_NO_WAIT);
CDEBUG(D_DLMTRACE, "Canceled %d unused locks from namespace %s\n",
canceled, ldlm_ns_name(ns));
}
static int lock_can_replay(struct obd_import *imp)
{
struct client_obd *cli = &imp->imp_obd->u.cli;
CDEBUG(D_HA, "check lock replay limit, inflights = %u(%u)\n",
atomic_read(&imp->imp_replay_inflight) - 1,
cli->cl_max_rpcs_in_flight);
/* +1 due to ldlm_lock_replay() increment */
return atomic_read(&imp->imp_replay_inflight) <
1 + min_t(u32, cli->cl_max_rpcs_in_flight, 8);
}
static int __ldlm_replay_locks(struct obd_import *imp, bool rate_limit)
{
struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
LIST_HEAD(list);
struct ldlm_lock *lock, *next;
int rc = 0;
ENTRY;
while (atomic_read(&imp->imp_replay_inflight) != 1)
cond_resched();
/* don't replay locks if import failed recovery */
if (test_bit(IMPF_VBR_FAILED, imp->imp_flags))
RETURN(0);
if (ldlm_cancel_unused_locks_before_replay)
ldlm_cancel_unused_locks_for_replay(ns);
ldlm_namespace_foreach(ns, ldlm_chain_lock_for_replay, &list);
list_for_each_entry_safe(lock, next, &list, l_pending_chain) {
list_del_init(&lock->l_pending_chain);
/* If we disconnected in the middle - cleanup and let
* reconnection to happen again. LU-14027 */
if (rc || (imp->imp_state != LUSTRE_IMP_REPLAY_LOCKS)) {
ldlm_lock_put(lock);
continue;
}
rc = replay_one_lock(imp, lock);
ldlm_lock_put(lock);
if (rate_limit)
wait_event_idle_exclusive(imp->imp_replay_waitq,
lock_can_replay(imp));
}
RETURN(rc);
}
/**
* ldlm_lock_replay_thread() - Lock replay uses rate control and can sleep
* waiting so must be in separate thread from
* ptlrpcd itself
* @data: pointer to the obd_import structure
*
* Return %0 always
*/
static int ldlm_lock_replay_thread(void *data)
{
struct obd_import *imp = data;
unshare_fs_struct();
CDEBUG(D_HA, "lock replay thread %s to %s@%s\n",
imp->imp_obd->obd_name, obd2cli_tgt(imp->imp_obd),
libcfs_nidstr(&imp->imp_connection->c_peer.nid));
__ldlm_replay_locks(imp, true);
atomic_dec(&imp->imp_replay_inflight);
ptlrpc_import_recovery_state_machine(imp);
class_import_put(imp);
return 0;
}
int ldlm_replay_locks(struct obd_import *imp)
{
struct task_struct *task;
int rc = 0;
/* ensure this doesn't fall to 0 before all have been queued */
if (atomic_inc_return(&imp->imp_replay_inflight) > 1) {
atomic_dec(&imp->imp_replay_inflight);
return 0;
}
class_import_get(imp);
task = kthread_run(ldlm_lock_replay_thread, imp, "ldlm_lock_replay");
if (IS_ERR(task)) {
rc = PTR_ERR(task);
CDEBUG(D_HA, "can't start lock replay thread: rc = %d\n", rc);
/* run lock replay without rate control */
rc = __ldlm_replay_locks(imp, false);
atomic_dec(&imp->imp_replay_inflight);
class_import_put(imp);
}
return rc;
}
