diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ldlm/ldlm_request.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/ldlm/ldlm_request.c | 2333 |
1 files changed, 2333 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c new file mode 100644 index 000000000000..1a690edaba03 --- /dev/null +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c @@ -0,0 +1,2333 @@ +/* + * 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) 2002, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2010, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + */ +/** + * 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 <lustre_dlm.h> +#include <obd_class.h> +#include <obd.h> + +#include "ldlm_internal.h" + +int ldlm_enqueue_min = OBD_TIMEOUT_DEFAULT; +CFS_MODULE_PARM(ldlm_enqueue_min, "i", int, 0644, + "lock enqueue timeout minimum"); + +/* in client side, whether the cached locks will be canceled before replay */ +unsigned int ldlm_cancel_unused_locks_before_replay = 1; + +static void interrupted_completion_wait(void *data) +{ +} + +struct lock_wait_data { + struct ldlm_lock *lwd_lock; + __u32 lwd_conn_cnt; +}; + +struct ldlm_async_args { + struct lustre_handle lock_handle; +}; + +int ldlm_expired_completion_wait(void *data) +{ + struct lock_wait_data *lwd = data; + struct ldlm_lock *lock = lwd->lwd_lock; + struct obd_import *imp; + struct obd_device *obd; + + ENTRY; + if (lock->l_conn_export == NULL) { + static cfs_time_t next_dump = 0, last_dump = 0; + + if (ptlrpc_check_suspend()) + RETURN(0); + + LCONSOLE_WARN("lock timed out (enqueued at "CFS_TIME_T", " + CFS_DURATION_T"s ago)\n", + lock->l_last_activity, + cfs_time_sub(cfs_time_current_sec(), + lock->l_last_activity)); + LDLM_DEBUG(lock, "lock timed out (enqueued at "CFS_TIME_T", " + CFS_DURATION_T"s ago); not entering recovery in " + "server code, just going back to sleep", + lock->l_last_activity, + cfs_time_sub(cfs_time_current_sec(), + lock->l_last_activity)); + if (cfs_time_after(cfs_time_current(), next_dump)) { + last_dump = next_dump; + next_dump = cfs_time_shift(300); + ldlm_namespace_dump(D_DLMTRACE, + ldlm_lock_to_ns(lock)); + if (last_dump == 0) + libcfs_debug_dumplog(); + } + RETURN(0); + } + + 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 "CFS_TIME_T", " + CFS_DURATION_T"s ago), entering recovery for %s@%s", + lock->l_last_activity, + cfs_time_sub(cfs_time_current_sec(), lock->l_last_activity), + obd2cli_tgt(obd), imp->imp_connection->c_remote_uuid.uuid); + + RETURN(0); +} +EXPORT_SYMBOL(ldlm_expired_completion_wait); + +/* We use the same basis for both server side and client side functions + from a single node. */ +int ldlm_get_enq_timeout(struct ldlm_lock *lock) +{ + int timeout = at_get(ldlm_lock_to_ns_at(lock)); + if (AT_OFF) + return obd_timeout / 2; + /* Since these are non-updating timeouts, we should be conservative. + It would be nice to have some kind of "early reply" mechanism for + lock callbacks too... */ + timeout = min_t(int, at_max, timeout + (timeout >> 1)); /* 150% */ + return max(timeout, ldlm_enqueue_min); +} +EXPORT_SYMBOL(ldlm_get_enq_timeout); + +/** + * Helper function for ldlm_completion_ast(), updating timings when lock is + * actually granted. + */ +static int ldlm_completion_tail(struct ldlm_lock *lock) +{ + long delay; + int result; + + if (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED) { + LDLM_DEBUG(lock, "client-side enqueue: destroyed"); + result = -EIO; + } else { + delay = cfs_time_sub(cfs_time_current_sec(), + lock->l_last_activity); + LDLM_DEBUG(lock, "client-side enqueue: granted after " + CFS_DURATION_T"s", delay); + + /* Update our time estimate */ + at_measured(ldlm_lock_to_ns_at(lock), + delay); + result = 0; + } + return result; +} + +/** + * 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. + */ +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_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED | + LDLM_FL_BLOCK_CONV))) { + wake_up(&lock->l_waitq); + RETURN(ldlm_completion_tail(lock)); + } + + LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, " + "going forward"); + ldlm_reprocess_all(lock->l_resource); + RETURN(0); +} +EXPORT_SYMBOL(ldlm_completion_ast_async); + +/** + * 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()); + * + * - during lock conversion (not used currently). + * + * If lock is not granted in the first case, this function waits until second + * or penultimate cases happen in some other thread. + * + */ +int ldlm_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data) +{ + /* XXX ALLOCATE - 160 bytes */ + struct lock_wait_data lwd; + struct obd_device *obd; + struct obd_import *imp = NULL; + struct l_wait_info lwi; + __u32 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_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED | + LDLM_FL_BLOCK_CONV))) { + wake_up(&lock->l_waitq); + RETURN(0); + } + + LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, " + "sleeping"); + +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; + } + + /* 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 = ldlm_get_enq_timeout(lock) * 2; + + lwd.lwd_lock = lock; + + if (lock->l_flags & LDLM_FL_NO_TIMEOUT) { + LDLM_DEBUG(lock, "waiting indefinitely because of NO_TIMEOUT"); + lwi = LWI_INTR(interrupted_completion_wait, &lwd); + } else { + lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(timeout), + ldlm_expired_completion_wait, + interrupted_completion_wait, &lwd); + } + + 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)) && + OBD_FAIL_CHECK_RESET(OBD_FAIL_LDLM_INTR_CP_AST, + OBD_FAIL_LDLM_CP_BL_RACE | OBD_FAIL_ONCE)) { + lock->l_flags |= LDLM_FL_FAIL_LOC; + rc = -EINTR; + } else { + /* Go to sleep until the lock is granted or cancelled. */ + rc = l_wait_event(lock->l_waitq, + is_granted_or_cancelled(lock), &lwi); + } + + if (rc) { + LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)", + rc); + RETURN(rc); + } + + RETURN(ldlm_completion_tail(lock)); +} +EXPORT_SYMBOL(ldlm_completion_ast); + +/** + * A helper to build a blocking AST function + * + * Perform a common operation for blocking ASTs: + * defferred lock cancellation. + * + * \param lock the lock blocking or canceling AST was called on + * \retval 0 + * \see mdt_blocking_ast + * \see ldlm_blocking_ast + */ +int ldlm_blocking_ast_nocheck(struct ldlm_lock *lock) +{ + int do_ast; + ENTRY; + + lock->l_flags |= LDLM_FL_CBPENDING; + 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); + +/** + * Server blocking AST + * + * ->l_blocking_ast() callback for LDLM locks acquired by server-side + * OBDs. + * + * \param lock the lock which blocks a request or cancelling lock + * \param desc unused + * \param data unused + * \param flag indicates whether this cancelling or blocking callback + * \retval 0 + * \see ldlm_blocking_ast_nocheck + */ +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); + +/** + * ->l_glimpse_ast() for DLM extent locks acquired on the server-side. See + * comment in filter_intent_policy() on why you may need this. + */ +int ldlm_glimpse_ast(struct ldlm_lock *lock, void *reqp) +{ + /* + * 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 + * current file size it calls ll{,u}_glimpse_size(), and (as locks are + * on the server), dummy glimpse callback fires and does + * nothing. Client still receives correct file size due to the + * following fragment in filter_intent_policy(): + * + * rc = l->l_glimpse_ast(l, NULL); // this will update the LVB + * if (rc != 0 && res->lr_namespace->ns_lvbo && + * res->lr_namespace->ns_lvbo->lvbo_update) { + * res->lr_namespace->ns_lvbo->lvbo_update(res, NULL, 0, 1); + * } + * + * that is, after glimpse_ast() fails, filter_lvbo_update() runs, and + * returns correct file size to the client. + */ + return -ELDLM_NO_LOCK_DATA; +} +EXPORT_SYMBOL(ldlm_glimpse_ast); + +/** + * Enqueue a local lock (typically on a server). + */ +int ldlm_cli_enqueue_local(struct ldlm_namespace *ns, + const struct ldlm_res_id *res_id, + ldlm_type_t type, ldlm_policy_data_t *policy, + ldlm_mode_t 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)); + if (unlikely(ns_is_client(ns))) { + CERROR("Trying to enqueue local lock in a shadow namespace\n"); + LBUG(); + } + + lock = ldlm_lock_create(ns, res_id, type, mode, &cbs, data, lvb_len, + lvb_type); + if (unlikely(!lock)) + GOTO(out_nolock, err = -ENOMEM); + + 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); + lock->l_flags |= LDLM_FL_LOCAL; + if (*flags & LDLM_FL_ATOMIC_CB) + lock->l_flags |= LDLM_FL_ATOMIC_CB; + + if (policy != NULL) + lock->l_policy_data = *policy; + if (client_cookie != NULL) + lock->l_client_cookie = *client_cookie; + if (type == LDLM_EXTENT) + lock->l_req_extent = policy->l_extent; + + err = ldlm_lock_enqueue(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_RELEASE(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 (bug 407) */ + lock_res_and_lock(lock); + /* Check that lock is not granted or failed, we might race. */ + if ((lock->l_req_mode != lock->l_granted_mode) && + !(lock->l_flags & LDLM_FL_FAILED)) { + /* Make sure that this lock will not be found by raced + * bl_ast and -EINVAL reply is sent to server anyways. + * bug 17645 */ + lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_FAILED | + LDLM_FL_ATOMIC_CB | LDLM_FL_CBPENDING; + 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"); + + ldlm_lock_decref_internal(lock, mode); + + /* 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); + ldlm_resource_unlink_lock(lock); + ldlm_lock_destroy_nolock(lock); + unlock_res_and_lock(lock); + } +} + +/** + * Finishing portion of client lock enqueue code. + * + * Called after receiving reply from server. + */ +int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req, + ldlm_type_t type, __u8 with_policy, ldlm_mode_t mode, + __u64 *flags, void *lvb, __u32 lvb_len, + struct lustre_handle *lockh,int rc) +{ + struct ldlm_namespace *ns = exp->exp_obd->obd_namespace; + int is_replay = *flags & LDLM_FL_REPLAY; + struct ldlm_lock *lock; + struct ldlm_reply *reply; + int cleanup_phase = 1; + int size = 0; + ENTRY; + + lock = ldlm_handle2lock(lockh); + /* ldlm_cli_enqueue is holding a reference on this lock. */ + if (!lock) { + LASSERT(type == LDLM_FLOCK); + RETURN(-ENOLCK); + } + + LASSERTF(ergo(lvb_len != 0, lvb_len == lock->l_lvb_len), + "lvb_len = %d, l_lvb_len = %d\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(&req->rq_pill, &RMF_DLM_REP); + if (reply == NULL) + GOTO(cleanup, rc = -EPROTO); + + if (lvb_len != 0) { + LASSERT(lvb != NULL); + + size = req_capsule_get_size(&req->rq_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); + } + } + + if (rc == ELDLM_LOCK_ABORTED) { + if (lvb_len != 0) + rc = ldlm_fill_lvb(lock, &req->rq_pill, RCL_SERVER, + lvb, size); + GOTO(cleanup, rc = (rc != 0 ? 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() */ + /* coverity[overrun-buffer-val] */ + 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; + } + + *flags = ldlm_flags_from_wire(reply->lock_flags); + lock->l_flags |= ldlm_flags_from_wire(reply->lock_flags & + LDLM_INHERIT_FLAGS); + /* move NO_TIMEOUT flag to the lock to force ldlm_lock_match() + * to wait with no timeout as well */ + lock->l_flags |= ldlm_flags_from_wire(reply->lock_flags & + LDLM_FL_NO_TIMEOUT); + unlock_res_and_lock(lock); + + CDEBUG(D_INFO, "local: %p, remote cookie: "LPX64", flags: 0x%llx\n", + lock, reply->lock_handle.cookie, *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 ((*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 (memcmp(reply->lock_desc.l_resource.lr_name.name, + lock->l_resource->lr_name.name, + sizeof(struct ldlm_res_id))) { + CDEBUG(D_INFO, "remote intent success, locking " + "(%ld,%ld,%ld) instead of " + "(%ld,%ld,%ld)\n", + (long)reply->lock_desc.l_resource.lr_name.name[0], + (long)reply->lock_desc.l_resource.lr_name.name[1], + (long)reply->lock_desc.l_resource.lr_name.name[2], + (long)lock->l_resource->lr_name.name[0], + (long)lock->l_resource->lr_name.name[1], + (long)lock->l_resource->lr_name.name[2]); + + 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) + if (!(type == LDLM_IBITS && + !(exp_connect_flags(exp) & OBD_CONNECT_IBITS))) + /* 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 (type != LDLM_PLAIN) + LDLM_DEBUG(lock,"client-side enqueue, new policy data"); + } + + if ((*flags) & LDLM_FL_AST_SENT || + /* Cancel extent locks as soon as possible on a liblustre client, + * because it cannot handle asynchronous ASTs robustly (see + * bug 7311). */ + (LIBLUSTRE_CLIENT && type == LDLM_EXTENT)) { + lock_res_and_lock(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 (lock->l_req_mode != lock->l_granted_mode) + rc = ldlm_fill_lvb(lock, &req->rq_pill, RCL_SERVER, + lock->l_lvb_data, size); + unlock_res_and_lock(lock); + if (rc < 0) { + cleanup_phase = 1; + GOTO(cleanup, rc); + } + } + + if (!is_replay) { + rc = ldlm_lock_enqueue(ns, &lock, NULL, flags); + if (lock->l_completion_ast != NULL) { + int err = lock->l_completion_ast(lock, *flags, NULL); + if (!rc) + rc = err; + if (rc) + cleanup_phase = 1; + } + } + + if (lvb_len && 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, mode); + /* Put lock 2 times, the second reference is held by ldlm_cli_enqueue */ + LDLM_LOCK_PUT(lock); + LDLM_LOCK_RELEASE(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_CACHE_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) +{ + int 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) +{ + int size = req_capsule_fmt_size(imp->imp_msg_magic, fmt, loc); + return ldlm_req_handles_avail(size, off); +} + +/** + * Cancel LRU locks and pack them into the enqueue request. Pack there the given + * \a count locks in \a 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. + */ +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; + int flags, avail, to_free, pack = 0; + LIST_HEAD(head); + 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); + + flags = ns_connect_lru_resize(ns) ? + LDLM_CANCEL_LRUR : LDLM_CANCEL_AGED; + to_free = !ns_connect_lru_resize(ns) && + opc == LDLM_ENQUEUE ? 1 : 0; + + /* 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, flags); + 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 incrment @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, req, 0); + /* Prepare and send separate cancel RPC for others. */ + ldlm_cli_cancel_list(cancels, count - pack, 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); + +/** + * Client-side lock enqueue. + * + * If a request has some specific initialisation it is passed in \a reqp, + * otherwise it is created in ldlm_cli_enqueue. + * + * Supports sync and async requests, pass \a async flag accordingly. If a + * request was created in ldlm_cli_enqueue and it is the async request, + * pass it to the caller in \a reqp. + */ +int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp, + struct ldlm_enqueue_info *einfo, + const struct ldlm_res_id *res_id, + ldlm_policy_data_t 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; + 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, + .lcs_weigh = einfo->ei_cb_wg + }; + lock = ldlm_lock_create(ns, res_id, einfo->ei_type, + einfo->ei_mode, &cbs, einfo->ei_cbdata, + lvb_len, lvb_type); + if (lock == NULL) + RETURN(-ENOMEM); + /* for the local lock, add the reference */ + ldlm_lock_addref_internal(lock, einfo->ei_mode); + ldlm_lock2handle(lock, lockh); + if (policy != NULL) { + /* INODEBITS_INTEROP: If the server does not support + * inodebits, we will request a plain lock in the + * descriptor (ldlm_lock2desc() below) but use an + * inodebits lock internally with both bits set. + */ + if (einfo->ei_type == LDLM_IBITS && + !(exp_connect_flags(exp) & + OBD_CONNECT_IBITS)) + lock->l_policy_data.l_inodebits.bits = + MDS_INODELOCK_LOOKUP | + MDS_INODELOCK_UPDATE; + else + lock->l_policy_data = *policy; + } + + if (einfo->ei_type == LDLM_EXTENT) + lock->l_req_extent = policy->l_extent; + LDLM_DEBUG(lock, "client-side enqueue START, flags %llx\n", + *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); + + /* lock not sent to server yet */ + + if (reqp == NULL || *reqp == NULL) { + req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp), + &RQF_LDLM_ENQUEUE, + LUSTRE_DLM_VERSION, + LDLM_ENQUEUE); + if (req == NULL) { + failed_lock_cleanup(ns, lock, einfo->ei_mode); + LDLM_LOCK_RELEASE(lock); + RETURN(-ENOMEM); + } + 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)); + } + + /* 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; + + /* Continue as normal. */ + if (!req_passed_in) { + if (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, + lvb_len); + ptlrpc_request_set_replen(req); + } + + /* + * Liblustre client doesn't get extent locks, except for O_APPEND case + * where [0, OBD_OBJECT_EOF] lock is taken, or truncate, where + * [i_size, OBD_OBJECT_EOF] lock is taken. + */ + LASSERT(ergo(LIBLUSTRE_CLIENT, einfo->ei_type != LDLM_EXTENT || + policy->l_extent.end == OBD_OBJECT_EOF)); + + if (async) { + LASSERT(reqp != NULL); + RETURN(0); + } + + LDLM_DEBUG(lock, "sending request"); + + rc = ptlrpc_queue_wait(req); + + err = ldlm_cli_enqueue_fini(exp, req, einfo->ei_type, policy ? 1 : 0, + einfo->ei_mode, flags, lvb, lvb_len, + lockh, rc); + + /* If ldlm_cli_enqueue_fini did not find the lock, we need to free + * one reference that we took */ + if (err == -ENOLCK) + LDLM_LOCK_RELEASE(lock); + else + rc = err; + + if (!req_passed_in && req != NULL) { + ptlrpc_req_finished(req); + if (reqp) + *reqp = NULL; + } + + RETURN(rc); +} +EXPORT_SYMBOL(ldlm_cli_enqueue); + +static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode, + __u32 *flags) +{ + struct ldlm_resource *res; + int rc; + ENTRY; + if (ns_is_client(ldlm_lock_to_ns(lock))) { + CERROR("Trying to cancel local lock\n"); + LBUG(); + } + LDLM_DEBUG(lock, "client-side local convert"); + + res = ldlm_lock_convert(lock, new_mode, flags); + if (res) { + ldlm_reprocess_all(res); + rc = 0; + } else { + rc = EDEADLOCK; + } + LDLM_DEBUG(lock, "client-side local convert handler END"); + LDLM_LOCK_PUT(lock); + RETURN(rc); +} + +/* FIXME: one of ldlm_cli_convert or the server side should reject attempted + * conversion of locks which are on the waiting or converting queue */ +/* Caller of this code is supposed to take care of lock readers/writers + accounting */ +int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, __u32 *flags) +{ + struct ldlm_request *body; + struct ldlm_reply *reply; + struct ldlm_lock *lock; + struct ldlm_resource *res; + struct ptlrpc_request *req; + int rc; + ENTRY; + + lock = ldlm_handle2lock(lockh); + if (!lock) { + LBUG(); + RETURN(-EINVAL); + } + *flags = 0; + + if (lock->l_conn_export == NULL) + RETURN(ldlm_cli_convert_local(lock, new_mode, flags)); + + LDLM_DEBUG(lock, "client-side convert"); + + req = ptlrpc_request_alloc_pack(class_exp2cliimp(lock->l_conn_export), + &RQF_LDLM_CONVERT, LUSTRE_DLM_VERSION, + LDLM_CONVERT); + if (req == NULL) { + LDLM_LOCK_PUT(lock); + RETURN(-ENOMEM); + } + + 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 = new_mode; + body->lock_flags = ldlm_flags_to_wire(*flags); + + + ptlrpc_request_set_replen(req); + rc = ptlrpc_queue_wait(req); + 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); + + if (req->rq_status) + GOTO(out, rc = req->rq_status); + + res = ldlm_lock_convert(lock, new_mode, &reply->lock_flags); + if (res != NULL) { + ldlm_reprocess_all(res); + /* Go to sleep until the lock is granted. */ + /* FIXME: or cancelled. */ + if (lock->l_completion_ast) { + rc = lock->l_completion_ast(lock, LDLM_FL_WAIT_NOREPROC, + NULL); + if (rc) + GOTO(out, rc); + } + } else { + rc = EDEADLOCK; + } + EXIT; + out: + LDLM_LOCK_PUT(lock); + ptlrpc_req_finished(req); + return rc; +} +EXPORT_SYMBOL(ldlm_cli_convert); + +/** + * Cancel locks locally. + * Returns: + * \retval LDLM_FL_LOCAL_ONLY if there is no need for a CANCEL RPC to the server + * \retval LDLM_FL_CANCELING otherwise; + * \retval 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"); + /* Set this flag to prevent others from getting new references*/ + lock_res_and_lock(lock); + lock->l_flags |= LDLM_FL_CBPENDING; + local_only = !!(lock->l_flags & + (LDLM_FL_LOCAL_ONLY|LDLM_FL_CANCEL_ON_BLOCK)); + ldlm_cancel_callback(lock); + rc = (lock->l_flags & LDLM_FL_BL_AST) ? + 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); + } + + RETURN(rc); +} + +/** + * Pack \a count locks in \a head into ldlm_request buffer of request \a req. + */ +static void ldlm_cancel_pack(struct ptlrpc_request *req, + struct list_head *head, int count) +{ + struct ldlm_request *dlm; + struct ldlm_lock *lock; + 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. */ + list_for_each_entry(lock, head, l_bl_ast) { + if (!count--) + break; + LASSERT(lock->l_conn_export); + /* Pack the lock handle to the given request buffer. */ + LDLM_DEBUG(lock, "packing"); + dlm->lock_handle[dlm->lock_count++] = lock->l_remote_handle; + packed++; + } + CDEBUG(D_DLMTRACE, "%d locks packed\n", packed); + EXIT; +} + +/** + * Prepare and send a batched cancel RPC. It will include \a count lock + * handles of locks given in \a cancels list. */ +int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels, + int count, ldlm_cancel_flags_t flags) +{ + struct ptlrpc_request *req = NULL; + struct obd_import *imp; + int free, sent = 0; + int rc = 0; + ENTRY; + + LASSERT(exp != NULL); + LASSERT(count > 0); + + 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 == NULL || imp->imp_invalid) { + 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); + } + + req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL; + req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL; + ptlrpc_at_set_req_timeout(req); + + ldlm_cancel_pack(req, cancels, count); + + ptlrpc_request_set_replen(req); + if (flags & LCF_ASYNC) { + ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1); + sent = count; + GOTO(out, 0); + } else { + rc = ptlrpc_queue_wait(req); + } + if (rc == ESTALE) { + CDEBUG(D_DLMTRACE, "client/server (nid %s) " + "out of sync -- not fatal\n", + libcfs_nid2str(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) { + ptlrpc_req_finished(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; + } + sent = count; + break; + } + + ptlrpc_req_finished(req); + EXIT; +out: + return sent ? sent : rc; +} +EXPORT_SYMBOL(ldlm_cli_cancel_req); + +static inline struct ldlm_pool *ldlm_imp2pl(struct obd_import *imp) +{ + LASSERT(imp != NULL); + return &imp->imp_obd->obd_namespace->ns_pool; +} + +/** + * Update client's OBD pool related fields with new SLV and Limit from \a req. + */ +int ldlm_cli_update_pool(struct ptlrpc_request *req) +{ + struct obd_device *obd; + __u64 new_slv; + __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: "LPU64", 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; + + /* Set new SLV and limit in OBD fields to make them accessible + * to the pool thread. We do not access obd_namespace and pool + * directly here as there is no reliable way to make sure that + * they are still alive at cleanup time. Evil races are possible + * which may cause Oops at that time. */ + write_lock(&obd->obd_pool_lock); + obd->obd_pool_slv = new_slv; + obd->obd_pool_limit = new_limit; + write_unlock(&obd->obd_pool_lock); + + RETURN(0); +} +EXPORT_SYMBOL(ldlm_cli_update_pool); + +/** + * Client side lock cancel. + * + * Lock must not have any readers or writers by this time. + */ +int ldlm_cli_cancel(struct lustre_handle *lockh, + ldlm_cancel_flags_t cancel_flags) +{ + struct obd_export *exp; + int avail, flags, count = 1; + __u64 rc = 0; + struct ldlm_namespace *ns; + struct ldlm_lock *lock; + LIST_HEAD(cancels); + ENTRY; + + /* concurrent cancels on the same handle can happen */ + lock = ldlm_handle2lock_long(lockh, LDLM_FL_CANCELING); + if (lock == NULL) { + LDLM_DEBUG_NOLOCK("lock is already being destroyed\n"); + RETURN(0); + } + + rc = ldlm_cli_cancel_local(lock); + if (rc == LDLM_FL_LOCAL_ONLY) { + LDLM_LOCK_RELEASE(lock); + RETURN(0); + } + /* Even if the lock is marked as LDLM_FL_BL_AST, 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. */ + LASSERT(list_empty(&lock->l_bl_ast)); + list_add(&lock->l_bl_ast, &cancels); + + exp = lock->l_conn_export; + 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); + flags = ns_connect_lru_resize(ns) ? + LDLM_CANCEL_LRUR : LDLM_CANCEL_AGED; + count += ldlm_cancel_lru_local(ns, &cancels, 0, avail - 1, + LCF_BL_AST, flags); + } + ldlm_cli_cancel_list(&cancels, count, NULL, cancel_flags); + RETURN(0); +} +EXPORT_SYMBOL(ldlm_cli_cancel); + +/** + * Locally cancel up to \a count locks in list \a cancels. + * Return the number of cancelled locks. + */ +int ldlm_cli_cancel_list_local(struct list_head *cancels, int count, + ldlm_cancel_flags_t 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 (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 (!(flags & LCF_BL_AST) && (rc == LDLM_FL_BL_AST)) { + LDLM_DEBUG(lock, "Cancel lock separately"); + list_del_init(&lock->l_bl_ast); + list_add(&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_RELEASE(lock); + count--; + } + } + if (bl_ast > 0) { + count -= bl_ast; + ldlm_cli_cancel_list(&head, bl_ast, NULL, 0); + } + + RETURN(count); +} +EXPORT_SYMBOL(ldlm_cli_cancel_list_local); + +/** + * 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, ...) + */ +static ldlm_policy_res_t ldlm_cancel_no_wait_policy(struct ldlm_namespace *ns, + struct ldlm_lock *lock, + int unused, int added, + int count) +{ + ldlm_policy_res_t result = LDLM_POLICY_CANCEL_LOCK; + ldlm_cancel_for_recovery cb = ns->ns_cancel_for_recovery; + lock_res_and_lock(lock); + + /* don't check added & count since we want to process all locks + * from unused list */ + switch (lock->l_resource->lr_type) { + case LDLM_EXTENT: + case LDLM_IBITS: + if (cb && cb(lock)) + break; + default: + result = LDLM_POLICY_SKIP_LOCK; + lock->l_flags |= LDLM_FL_SKIPPED; + break; + } + + unlock_res_and_lock(lock); + RETURN(result); +} + +/** + * Callback function for LRU-resize policy. Decides whether to keep + * \a lock in LRU for current \a LRU size \a unused, added in current + * scan \a added and number of locks to be preferably canceled \a count. + * + * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning + * + * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU + */ +static ldlm_policy_res_t ldlm_cancel_lrur_policy(struct ldlm_namespace *ns, + struct ldlm_lock *lock, + int unused, int added, + int count) +{ + cfs_time_t cur = cfs_time_current(); + struct ldlm_pool *pl = &ns->ns_pool; + __u64 slv, lvf, lv; + cfs_time_t la; + + /* Stop LRU processing when we reach past @count or have checked all + * locks in LRU. */ + if (count && added >= count) + return LDLM_POLICY_KEEP_LOCK; + + slv = ldlm_pool_get_slv(pl); + lvf = ldlm_pool_get_lvf(pl); + la = cfs_duration_sec(cfs_time_sub(cur, + lock->l_last_used)); + lv = lvf * la * unused; + + /* Inform pool about current CLV to see it via proc. */ + ldlm_pool_set_clv(pl, lv); + + /* Stop when SLV is not yet come from server or lv is smaller than + * it is. */ + return (slv == 0 || lv < slv) ? + LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK; +} + +/** + * Callback function for proc used policy. Makes decision whether to keep + * \a lock in LRU for current \a LRU size \a unused, added in current scan \a + * added and number of locks to be preferably canceled \a count. + * + * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning + * + * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU + */ +static ldlm_policy_res_t ldlm_cancel_passed_policy(struct ldlm_namespace *ns, + struct ldlm_lock *lock, + int unused, int added, + int count) +{ + /* Stop LRU processing when we reach past @count or have checked all + * locks in LRU. */ + return (added >= count) ? + LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK; +} + +/** + * Callback function for aged policy. Makes decision whether to keep \a lock in + * LRU for current LRU size \a unused, added in current scan \a added and + * number of locks to be preferably canceled \a count. + * + * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning + * + * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU + */ +static ldlm_policy_res_t ldlm_cancel_aged_policy(struct ldlm_namespace *ns, + struct ldlm_lock *lock, + int unused, int added, + int count) +{ + /* Stop LRU processing if young lock is found and we reach past count */ + return ((added >= count) && + cfs_time_before(cfs_time_current(), + cfs_time_add(lock->l_last_used, + ns->ns_max_age))) ? + LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK; +} + +/** + * Callback function for default policy. Makes decision whether to keep \a lock + * in LRU for current LRU size \a unused, added in current scan \a added and + * number of locks to be preferably canceled \a count. + * + * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning + * + * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU + */ +static ldlm_policy_res_t ldlm_cancel_default_policy(struct ldlm_namespace *ns, + struct ldlm_lock *lock, + int unused, int added, + int count) +{ + /* Stop LRU processing when we reach past count or have checked all + * locks in LRU. */ + return (added >= count) ? + LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK; +} + +typedef ldlm_policy_res_t (*ldlm_cancel_lru_policy_t)(struct ldlm_namespace *, + struct ldlm_lock *, int, + int, int); + +static ldlm_cancel_lru_policy_t +ldlm_cancel_lru_policy(struct ldlm_namespace *ns, int flags) +{ + if (flags & LDLM_CANCEL_NO_WAIT) + return ldlm_cancel_no_wait_policy; + + if (ns_connect_lru_resize(ns)) { + if (flags & LDLM_CANCEL_SHRINK) + /* We kill passed number of old locks. */ + return ldlm_cancel_passed_policy; + else if (flags & LDLM_CANCEL_LRUR) + return ldlm_cancel_lrur_policy; + else if (flags & LDLM_CANCEL_PASSED) + return ldlm_cancel_passed_policy; + } else { + if (flags & LDLM_CANCEL_AGED) + return ldlm_cancel_aged_policy; + } + + return ldlm_cancel_default_policy; +} + +/** + * - Free space in LRU for \a count new locks, + * redundant unused locks are canceled locally; + * - also cancel locally unused aged locks; + * - do not cancel more than \a max locks; + * - GET the found locks and add them into the \a 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. + * + * Calling policies for enabled LRU resize: + * ---------------------------------------- + * flags & LDLM_CANCEL_LRUR - use LRU resize policy (SLV from server) to + * cancel not more than \a count locks; + * + * flags & LDLM_CANCEL_PASSED - cancel \a count number of old locks (located at + * the beginning of LRU list); + * + * flags & LDLM_CANCEL_SHRINK - cancel not more than \a count locks according to + * memory pressre policy function; + * + * flags & LDLM_CANCEL_AGED - cancel \a count locks according to "aged policy". + * + * flags & LDLM_CANCEL_NO_WAIT - cancel as many unused locks as possible + * (typically before replaying locks) w/o + * sending any RPCs or waiting for any + * outstanding RPC to complete. + */ +static int ldlm_prepare_lru_list(struct ldlm_namespace *ns, struct list_head *cancels, + int count, int max, int flags) +{ + ldlm_cancel_lru_policy_t pf; + struct ldlm_lock *lock, *next; + int added = 0, unused, remained; + ENTRY; + + spin_lock(&ns->ns_lock); + unused = ns->ns_nr_unused; + remained = unused; + + if (!ns_connect_lru_resize(ns)) + count += unused - ns->ns_max_unused; + + pf = ldlm_cancel_lru_policy(ns, flags); + LASSERT(pf != NULL); + + while (!list_empty(&ns->ns_unused_list)) { + ldlm_policy_res_t result; + + /* all unused locks */ + if (remained-- <= 0) + break; + + /* For any flags, stop scanning if @max is reached. */ + if (max && added >= max) + break; + + list_for_each_entry_safe(lock, next, &ns->ns_unused_list, + l_lru) { + /* No locks which got blocking requests. */ + LASSERT(!(lock->l_flags & LDLM_FL_BL_AST)); + + if (flags & LDLM_CANCEL_NO_WAIT && + lock->l_flags & LDLM_FL_SKIPPED) + /* already processed */ + continue; + + /* Somebody is already doing CANCEL. No need for this + * lock in LRU, do not traverse it again. */ + if (!(lock->l_flags & LDLM_FL_CANCELING)) + break; + + ldlm_lock_remove_from_lru_nolock(lock); + } + if (&lock->l_lru == &ns->ns_unused_list) + break; + + LDLM_LOCK_GET(lock); + spin_unlock(&ns->ns_lock); + lu_ref_add(&lock->l_reference, __FUNCTION__, current); + + /* 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, unused, added, count); + if (result == LDLM_POLICY_KEEP_LOCK) { + lu_ref_del(&lock->l_reference, + __FUNCTION__, current); + LDLM_LOCK_RELEASE(lock); + spin_lock(&ns->ns_lock); + break; + } + if (result == LDLM_POLICY_SKIP_LOCK) { + lu_ref_del(&lock->l_reference, + __func__, current); + LDLM_LOCK_RELEASE(lock); + spin_lock(&ns->ns_lock); + continue; + } + + lock_res_and_lock(lock); + /* Check flags again under the lock. */ + if ((lock->l_flags & LDLM_FL_CANCELING) || + (ldlm_lock_remove_from_lru(lock) == 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. */ + unlock_res_and_lock(lock); + lu_ref_del(&lock->l_reference, + __FUNCTION__, current); + LDLM_LOCK_RELEASE(lock); + spin_lock(&ns->ns_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. */ + lock->l_flags &= ~LDLM_FL_CANCEL_ON_BLOCK; + + /* 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; + + /* 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 bug 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); + lu_ref_del(&lock->l_reference, __FUNCTION__, current); + spin_lock(&ns->ns_lock); + added++; + unused--; + } + spin_unlock(&ns->ns_lock); + RETURN(added); +} + +int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels, + int count, int max, ldlm_cancel_flags_t cancel_flags, + int flags) +{ + int added; + added = ldlm_prepare_lru_list(ns, cancels, count, max, flags); + if (added <= 0) + return added; + return ldlm_cli_cancel_list_local(cancels, added, cancel_flags); +} + +/** + * Cancel at least \a nr locks from given namespace LRU. + * + * 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. + */ +int ldlm_cancel_lru(struct ldlm_namespace *ns, int nr, + ldlm_cancel_flags_t cancel_flags, + int 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, nr, 0, flags); + rc = ldlm_bl_to_thread_list(ns, NULL, &cancels, count, cancel_flags); + if (rc == 0) + RETURN(count); + + RETURN(0); +} + +/** + * 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. + */ +int ldlm_cancel_resource_local(struct ldlm_resource *res, + struct list_head *cancels, + ldlm_policy_data_t *policy, + ldlm_mode_t mode, int lock_flags, + ldlm_cancel_flags_t 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); + //LBUG(); + continue; + } + + if (lock->l_readers || lock->l_writers) + continue; + + /* If somebody is already doing CANCEL, or blocking AST came, + * skip this lock. */ + if (lock->l_flags & LDLM_FL_BL_AST || + lock->l_flags & LDLM_FL_CANCELING) + 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) && + !(lock->l_policy_data.l_inodebits.bits & + policy->l_inodebits.bits)) + 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); + +/** + * Cancel client-side locks from a list and send/prepare cancel RPCs to the + * server. + * If \a req is NULL, send CANCEL request to server with handles of locks + * in the \a cancels. If EARLY_CANCEL is not supported, send CANCEL requests + * separately per lock. + * If \a req is not NULL, put handles of locks in \a cancels into the request + * buffer at the offset \a off. + * Destroy \a cancels at the end. + */ +int ldlm_cli_cancel_list(struct list_head *cancels, int count, + struct ptlrpc_request *req, ldlm_cancel_flags_t flags) +{ + struct ldlm_lock *lock; + int res = 0; + ENTRY; + + if (list_empty(cancels) || count == 0) + RETURN(0); + + /* 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(!list_empty(cancels)); + lock = list_entry(cancels->next, struct ldlm_lock, + l_bl_ast); + LASSERT(lock->l_conn_export); + + if (exp_connect_cancelset(lock->l_conn_export)) { + res = count; + if (req) + ldlm_cancel_pack(req, cancels, count); + else + res = ldlm_cli_cancel_req(lock->l_conn_export, + cancels, count, + flags); + } else { + res = ldlm_cli_cancel_req(lock->l_conn_export, + 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; + ldlm_lock_list_put(cancels, l_bl_ast, res); + } + LASSERT(count == 0); + RETURN(0); +} +EXPORT_SYMBOL(ldlm_cli_cancel_list); + +/** + * Cancel all locks on a resource that have 0 readers/writers. + * + * If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying + * to notify the server. */ +int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns, + const struct ldlm_res_id *res_id, + ldlm_policy_data_t *policy, + ldlm_mode_t mode, + ldlm_cancel_flags_t flags, + void *opaque) +{ + struct ldlm_resource *res; + LIST_HEAD(cancels); + int count; + int rc; + ENTRY; + + res = ldlm_resource_get(ns, NULL, res_id, 0, 0); + if (res == NULL) { + /* This is not a problem. */ + CDEBUG(D_INFO, "No resource "LPU64"\n", res_id->name[0]); + RETURN(0); + } + + LDLM_RESOURCE_ADDREF(res); + count = ldlm_cancel_resource_local(res, &cancels, policy, mode, + 0, flags | LCF_BL_AST, opaque); + rc = ldlm_cli_cancel_list(&cancels, count, NULL, flags); + if (rc != ELDLM_OK) + CERROR("ldlm_cli_cancel_unused_resource: %d\n", rc); + + LDLM_RESOURCE_DELREF(res); + 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(cfs_hash_t *hs, cfs_hash_bd_t *bd, + struct hlist_node *hnode, void *arg) +{ + struct ldlm_resource *res = cfs_hash_object(hs, hnode); + struct ldlm_cli_cancel_arg *lc = arg; + int rc; + + rc = ldlm_cli_cancel_unused_resource(ldlm_res_to_ns(res), &res->lr_name, + NULL, LCK_MINMODE, + lc->lc_flags, lc->lc_opaque); + if (rc != 0) { + CERROR("ldlm_cli_cancel_unused ("LPU64"): %d\n", + res->lr_name.name[0], rc); + } + /* must return 0 for hash iteration */ + return 0; +} + +/** + * 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. */ +int ldlm_cli_cancel_unused(struct ldlm_namespace *ns, + const struct ldlm_res_id *res_id, + ldlm_cancel_flags_t 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_MINMODE, flags, + opaque)); + } else { + cfs_hash_for_each_nolock(ns->ns_rs_hash, + ldlm_cli_hash_cancel_unused, &arg); + RETURN(ELDLM_OK); + } +} +EXPORT_SYMBOL(ldlm_cli_cancel_unused); + +/* Lock iterators. */ + +int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter, + void *closure) +{ + struct list_head *tmp, *next; + struct ldlm_lock *lock; + int rc = LDLM_ITER_CONTINUE; + + ENTRY; + + if (!res) + RETURN(LDLM_ITER_CONTINUE); + + lock_res(res); + list_for_each_safe(tmp, next, &res->lr_granted) { + lock = list_entry(tmp, struct ldlm_lock, l_res_link); + + if (iter(lock, closure) == LDLM_ITER_STOP) + GOTO(out, rc = LDLM_ITER_STOP); + } + + list_for_each_safe(tmp, next, &res->lr_converting) { + lock = list_entry(tmp, struct ldlm_lock, l_res_link); + + if (iter(lock, closure) == LDLM_ITER_STOP) + GOTO(out, rc = LDLM_ITER_STOP); + } + + list_for_each_safe(tmp, next, &res->lr_waiting) { + lock = list_entry(tmp, struct ldlm_lock, l_res_link); + + if (iter(lock, closure) == LDLM_ITER_STOP) + GOTO(out, rc = LDLM_ITER_STOP); + } + out: + unlock_res(res); + RETURN(rc); +} +EXPORT_SYMBOL(ldlm_resource_foreach); + +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(cfs_hash_t *hs, cfs_hash_bd_t *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); + +} +EXPORT_SYMBOL(ldlm_namespace_foreach); + +/* non-blocking function to manipulate a lock whose cb_data is being put away. + * return 0: find no resource + * > 0: must be LDLM_ITER_STOP/LDLM_ITER_CONTINUE. + * < 0: 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; + + if (ns == NULL) { + CERROR("must pass in namespace\n"); + LBUG(); + } + + res = ldlm_resource_get(ns, NULL, res_id, 0, 0); + if (res == NULL) + RETURN(0); + + LDLM_RESOURCE_ADDREF(res); + rc = ldlm_resource_foreach(res, iter, data); + LDLM_RESOURCE_DELREF(res); + 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 %p next %p prev %p\n", + lock, &lock->l_pending_chain.next,&lock->l_pending_chain.prev); + /* bug 9573: don't replay locks left after eviction, or + * bug 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_CANCELING))) { + 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, + struct ldlm_async_args *aa, int rc) +{ + struct ldlm_lock *lock; + struct ldlm_reply *reply; + struct obd_export *exp; + + ENTRY; + atomic_dec(&req->rq_import->imp_replay_inflight); + 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 "LPX64 + " remote cookie "LPX64 " from server %s id %s\n", + aa->lock_handle.cookie, reply->lock_handle.cookie, + req->rq_export->exp_client_uuid.uuid, + libcfs_id2str(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() */ + /* coverity[overrun-buffer-val] */ + 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) + 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; + + + /* Bug 11974: Do not replay a lock which is actively being canceled */ + if (lock->l_flags & LDLM_FL_CANCELING) { + 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 (lock->l_flags & LDLM_FL_CANCEL_ON_BLOCK) { + 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 they differ, but we have a granted mode, then we were granted + * one mode and now want another: ergo, converting. + * + * 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 (lock->l_granted_mode == lock->l_req_mode) + flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_GRANTED; + else if (lock->l_granted_mode) + flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_CONV; + 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 (req == NULL) + RETURN(-ENOMEM); + + /* We're part of recovery, so don't wait for it. */ + req->rq_send_state = LUSTRE_IMP_REPLAY_LOCKS; + + 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. + * bug 6063 */ + lustre_msg_set_flags(req->rq_reqmsg, MSG_REQ_REPLAY_DONE); + + LDLM_DEBUG(lock, "replaying lock:"); + + atomic_inc(&req->rq_import->imp_replay_inflight); + CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args)); + aa = ptlrpc_req_async_args(req); + aa->lock_handle = body->lock_handle[0]; + req->rq_interpret_reply = (ptlrpc_interpterer_t)replay_lock_interpret; + ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1); + + 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); + + /* We don't need to care whether or not LRU resize is enabled + * because the LDLM_CANCEL_NO_WAIT policy doesn't use the + * count parameter */ + canceled = ldlm_cancel_lru_local(ns, &cancels, ns->ns_nr_unused, 0, + LCF_LOCAL, LDLM_CANCEL_NO_WAIT); + + CDEBUG(D_DLMTRACE, "Canceled %d unused locks from namespace %s\n", + canceled, ldlm_ns_name(ns)); +} + +int ldlm_replay_locks(struct obd_import *imp) +{ + struct ldlm_namespace *ns = imp->imp_obd->obd_namespace; + LIST_HEAD(list); + struct ldlm_lock *lock, *next; + int rc = 0; + + ENTRY; + + LASSERT(atomic_read(&imp->imp_replay_inflight) == 0); + + /* don't replay locks if import failed recovery */ + if (imp->imp_vbr_failed) + RETURN(0); + + /* ensure this doesn't fall to 0 before all have been queued */ + atomic_inc(&imp->imp_replay_inflight); + + 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 (rc) { + LDLM_LOCK_RELEASE(lock); + continue; /* or try to do the rest? */ + } + rc = replay_one_lock(imp, lock); + LDLM_LOCK_RELEASE(lock); + } + + atomic_dec(&imp->imp_replay_inflight); + + RETURN(rc); +} +EXPORT_SYMBOL(ldlm_replay_locks); |