/* * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 only, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is included * in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU General Public License * version 2 along with this program; If not, see * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * * GPL HEADER END */ /* * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. * Use is subject to license terms. * * Copyright (c) 2011, 2013, Intel Corporation. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. * * Implementation of cl_lock for LOV layer. * * Author: Nikita Danilov */ #define DEBUG_SUBSYSTEM S_LOV #include "lov_cl_internal.h" /** \addtogroup lov * @{ */ static struct cl_lock_closure *lov_closure_get(const struct lu_env *env, struct cl_lock *parent); static int lov_lock_unuse(const struct lu_env *env, const struct cl_lock_slice *slice); /***************************************************************************** * * Lov lock operations. * */ static struct lov_sublock_env *lov_sublock_env_get(const struct lu_env *env, struct cl_lock *parent, struct lov_lock_sub *lls) { struct lov_sublock_env *subenv; struct lov_io *lio = lov_env_io(env); struct cl_io *io = lio->lis_cl.cis_io; struct lov_io_sub *sub; subenv = &lov_env_session(env)->ls_subenv; /* * FIXME: We tend to use the subio's env & io to call the sublock * lock operations because osc lock sometimes stores some control * variables in thread's IO infomation(Now only lockless information). * However, if the lock's host(object) is different from the object * for current IO, we have no way to get the subenv and subio because * they are not initialized at all. As a temp fix, in this case, * we still borrow the parent's env to call sublock operations. */ if (!io || !cl_object_same(io->ci_obj, parent->cll_descr.cld_obj)) { subenv->lse_env = env; subenv->lse_io = io; subenv->lse_sub = NULL; } else { sub = lov_sub_get(env, lio, lls->sub_stripe); if (!IS_ERR(sub)) { subenv->lse_env = sub->sub_env; subenv->lse_io = sub->sub_io; subenv->lse_sub = sub; } else { subenv = (void*)sub; } } return subenv; } static void lov_sublock_env_put(struct lov_sublock_env *subenv) { if (subenv && subenv->lse_sub) lov_sub_put(subenv->lse_sub); } static void lov_sublock_adopt(const struct lu_env *env, struct lov_lock *lck, struct cl_lock *sublock, int idx, struct lov_lock_link *link) { struct lovsub_lock *lsl; struct cl_lock *parent = lck->lls_cl.cls_lock; int rc; LASSERT(cl_lock_is_mutexed(parent)); LASSERT(cl_lock_is_mutexed(sublock)); ENTRY; lsl = cl2sub_lock(sublock); /* * check that sub-lock doesn't have lock link to this top-lock. */ LASSERT(lov_lock_link_find(env, lck, lsl) == NULL); LASSERT(idx < lck->lls_nr); lck->lls_sub[idx].sub_lock = lsl; lck->lls_nr_filled++; LASSERT(lck->lls_nr_filled <= lck->lls_nr); cfs_list_add_tail(&link->lll_list, &lsl->lss_parents); link->lll_idx = idx; link->lll_super = lck; cl_lock_get(parent); lu_ref_add(&parent->cll_reference, "lov-child", sublock); lck->lls_sub[idx].sub_flags |= LSF_HELD; cl_lock_user_add(env, sublock); rc = lov_sublock_modify(env, lck, lsl, &sublock->cll_descr, idx); LASSERT(rc == 0); /* there is no way this can fail, currently */ EXIT; } static struct cl_lock *lov_sublock_alloc(const struct lu_env *env, const struct cl_io *io, struct lov_lock *lck, int idx, struct lov_lock_link **out) { struct cl_lock *sublock; struct cl_lock *parent; struct lov_lock_link *link; LASSERT(idx < lck->lls_nr); ENTRY; OBD_SLAB_ALLOC_PTR_GFP(link, lov_lock_link_kmem, __GFP_IO); if (link != NULL) { struct lov_sublock_env *subenv; struct lov_lock_sub *lls; struct cl_lock_descr *descr; parent = lck->lls_cl.cls_lock; lls = &lck->lls_sub[idx]; descr = &lls->sub_got; subenv = lov_sublock_env_get(env, parent, lls); if (!IS_ERR(subenv)) { /* CAVEAT: Don't try to add a field in lov_lock_sub * to remember the subio. This is because lock is able * to be cached, but this is not true for IO. This * further means a sublock might be referenced in * different io context. -jay */ sublock = cl_lock_hold(subenv->lse_env, subenv->lse_io, descr, "lov-parent", parent); lov_sublock_env_put(subenv); } else { /* error occurs. */ sublock = (void*)subenv; } if (!IS_ERR(sublock)) *out = link; else OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem); } else sublock = ERR_PTR(-ENOMEM); RETURN(sublock); } static void lov_sublock_unlock(const struct lu_env *env, struct lovsub_lock *lsl, struct cl_lock_closure *closure, struct lov_sublock_env *subenv) { ENTRY; lov_sublock_env_put(subenv); lsl->lss_active = NULL; cl_lock_disclosure(env, closure); EXIT; } static int lov_sublock_lock(const struct lu_env *env, struct lov_lock *lck, struct lov_lock_sub *lls, struct cl_lock_closure *closure, struct lov_sublock_env **lsep) { struct lovsub_lock *sublock; struct cl_lock *child; int result = 0; ENTRY; LASSERT(cfs_list_empty(&closure->clc_list)); sublock = lls->sub_lock; child = sublock->lss_cl.cls_lock; result = cl_lock_closure_build(env, child, closure); if (result == 0) { struct cl_lock *parent = closure->clc_origin; LASSERT(cl_lock_is_mutexed(child)); sublock->lss_active = parent; if (unlikely((child->cll_state == CLS_FREEING) || (child->cll_flags & CLF_CANCELLED))) { struct lov_lock_link *link; /* * we could race with lock deletion which temporarily * put the lock in freeing state, bug 19080. */ LASSERT(!(lls->sub_flags & LSF_HELD)); link = lov_lock_link_find(env, lck, sublock); LASSERT(link != NULL); lov_lock_unlink(env, link, sublock); lov_sublock_unlock(env, sublock, closure, NULL); lck->lls_cancel_race = 1; result = CLO_REPEAT; } else if (lsep) { struct lov_sublock_env *subenv; subenv = lov_sublock_env_get(env, parent, lls); if (IS_ERR(subenv)) { lov_sublock_unlock(env, sublock, closure, NULL); result = PTR_ERR(subenv); } else { *lsep = subenv; } } } RETURN(result); } /** * Updates the result of a top-lock operation from a result of sub-lock * sub-operations. Top-operations like lov_lock_{enqueue,use,unuse}() iterate * over sub-locks and lov_subresult() is used to calculate return value of a * top-operation. To this end, possible return values of sub-operations are * ordered as * * - 0 success * - CLO_WAIT wait for event * - CLO_REPEAT repeat top-operation * - -ne fundamental error * * Top-level return code can only go down through this list. CLO_REPEAT * overwrites CLO_WAIT, because lock mutex was released and sleeping condition * has to be rechecked by the upper layer. */ static int lov_subresult(int result, int rc) { int result_rank; int rc_rank; ENTRY; LASSERTF(result <= 0 || result == CLO_REPEAT || result == CLO_WAIT, "result = %d", result); LASSERTF(rc <= 0 || rc == CLO_REPEAT || rc == CLO_WAIT, "rc = %d\n", rc); CLASSERT(CLO_WAIT < CLO_REPEAT); /* calculate ranks in the ordering above */ result_rank = result < 0 ? 1 + CLO_REPEAT : result; rc_rank = rc < 0 ? 1 + CLO_REPEAT : rc; if (result_rank < rc_rank) result = rc; RETURN(result); } /** * Creates sub-locks for a given lov_lock for the first time. * * Goes through all sub-objects of top-object, and creates sub-locks on every * sub-object intersecting with top-lock extent. This is complicated by the * fact that top-lock (that is being created) can be accessed concurrently * through already created sub-locks (possibly shared with other top-locks). */ static int lov_lock_sub_init(const struct lu_env *env, struct lov_lock *lck, const struct cl_io *io) { int result = 0; int i; int nr; obd_off start; obd_off end; obd_off file_start; obd_off file_end; struct lov_object *loo = cl2lov(lck->lls_cl.cls_obj); struct lov_layout_raid0 *r0 = lov_r0(loo); struct cl_lock *parent = lck->lls_cl.cls_lock; ENTRY; lck->lls_orig = parent->cll_descr; file_start = cl_offset(lov2cl(loo), parent->cll_descr.cld_start); file_end = cl_offset(lov2cl(loo), parent->cll_descr.cld_end + 1) - 1; for (i = 0, nr = 0; i < r0->lo_nr; i++) { /* * XXX for wide striping smarter algorithm is desirable, * breaking out of the loop, early. */ if (lov_stripe_intersects(loo->lo_lsm, i, file_start, file_end, &start, &end)) nr++; } LASSERT(nr > 0); OBD_ALLOC_LARGE(lck->lls_sub, nr * sizeof lck->lls_sub[0]); if (lck->lls_sub == NULL) RETURN(-ENOMEM); lck->lls_nr = nr; /* * First, fill in sub-lock descriptions in * lck->lls_sub[].sub_descr. They are used by lov_sublock_alloc() * (called below in this function, and by lov_lock_enqueue()) to * create sub-locks. At this moment, no other thread can access * top-lock. */ for (i = 0, nr = 0; i < r0->lo_nr; ++i) { if (lov_stripe_intersects(loo->lo_lsm, i, file_start, file_end, &start, &end)) { struct cl_lock_descr *descr; descr = &lck->lls_sub[nr].sub_descr; LASSERT(descr->cld_obj == NULL); descr->cld_obj = lovsub2cl(r0->lo_sub[i]); descr->cld_start = cl_index(descr->cld_obj, start); descr->cld_end = cl_index(descr->cld_obj, end); descr->cld_mode = parent->cll_descr.cld_mode; descr->cld_gid = parent->cll_descr.cld_gid; descr->cld_enq_flags = parent->cll_descr.cld_enq_flags; /* XXX has no effect */ lck->lls_sub[nr].sub_got = *descr; lck->lls_sub[nr].sub_stripe = i; nr++; } } LASSERT(nr == lck->lls_nr); /* * Then, create sub-locks. Once at least one sub-lock was created, * top-lock can be reached by other threads. */ for (i = 0; i < lck->lls_nr; ++i) { struct cl_lock *sublock; struct lov_lock_link *link; if (lck->lls_sub[i].sub_lock == NULL) { sublock = lov_sublock_alloc(env, io, lck, i, &link); if (IS_ERR(sublock)) { result = PTR_ERR(sublock); break; } cl_lock_get_trust(sublock); cl_lock_mutex_get(env, sublock); cl_lock_mutex_get(env, parent); /* * recheck under mutex that sub-lock wasn't created * concurrently, and that top-lock is still alive. */ if (lck->lls_sub[i].sub_lock == NULL && parent->cll_state < CLS_FREEING) { lov_sublock_adopt(env, lck, sublock, i, link); cl_lock_mutex_put(env, parent); } else { OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem); cl_lock_mutex_put(env, parent); cl_lock_unhold(env, sublock, "lov-parent", parent); } cl_lock_mutex_put(env, sublock); cl_lock_put(env, sublock); } } /* * Some sub-locks can be missing at this point. This is not a problem, * because enqueue will create them anyway. Main duty of this function * is to fill in sub-lock descriptions in a race free manner. */ RETURN(result); } static int lov_sublock_release(const struct lu_env *env, struct lov_lock *lck, int i, int deluser, int rc) { struct cl_lock *parent = lck->lls_cl.cls_lock; LASSERT(cl_lock_is_mutexed(parent)); ENTRY; if (lck->lls_sub[i].sub_flags & LSF_HELD) { struct cl_lock *sublock; int dying; LASSERT(lck->lls_sub[i].sub_lock != NULL); sublock = lck->lls_sub[i].sub_lock->lss_cl.cls_lock; LASSERT(cl_lock_is_mutexed(sublock)); lck->lls_sub[i].sub_flags &= ~LSF_HELD; if (deluser) cl_lock_user_del(env, sublock); /* * If the last hold is released, and cancellation is pending * for a sub-lock, release parent mutex, to avoid keeping it * while sub-lock is being paged out. */ dying = (sublock->cll_descr.cld_mode == CLM_PHANTOM || sublock->cll_descr.cld_mode == CLM_GROUP || (sublock->cll_flags & (CLF_CANCELPEND|CLF_DOOMED))) && sublock->cll_holds == 1; if (dying) cl_lock_mutex_put(env, parent); cl_lock_unhold(env, sublock, "lov-parent", parent); if (dying) { cl_lock_mutex_get(env, parent); rc = lov_subresult(rc, CLO_REPEAT); } /* * From now on lck->lls_sub[i].sub_lock is a "weak" pointer, * not backed by a reference on a * sub-lock. lovsub_lock_delete() will clear * lck->lls_sub[i].sub_lock under semaphores, just before * sub-lock is destroyed. */ } RETURN(rc); } static void lov_sublock_hold(const struct lu_env *env, struct lov_lock *lck, int i) { struct cl_lock *parent = lck->lls_cl.cls_lock; LASSERT(cl_lock_is_mutexed(parent)); ENTRY; if (!(lck->lls_sub[i].sub_flags & LSF_HELD)) { struct cl_lock *sublock; LASSERT(lck->lls_sub[i].sub_lock != NULL); sublock = lck->lls_sub[i].sub_lock->lss_cl.cls_lock; LASSERT(cl_lock_is_mutexed(sublock)); LASSERT(sublock->cll_state != CLS_FREEING); lck->lls_sub[i].sub_flags |= LSF_HELD; cl_lock_get_trust(sublock); cl_lock_hold_add(env, sublock, "lov-parent", parent); cl_lock_user_add(env, sublock); cl_lock_put(env, sublock); } EXIT; } static void lov_lock_fini(const struct lu_env *env, struct cl_lock_slice *slice) { struct lov_lock *lck; int i; ENTRY; lck = cl2lov_lock(slice); LASSERT(lck->lls_nr_filled == 0); if (lck->lls_sub != NULL) { for (i = 0; i < lck->lls_nr; ++i) /* * No sub-locks exists at this point, as sub-lock has * a reference on its parent. */ LASSERT(lck->lls_sub[i].sub_lock == NULL); OBD_FREE_LARGE(lck->lls_sub, lck->lls_nr * sizeof lck->lls_sub[0]); } OBD_SLAB_FREE_PTR(lck, lov_lock_kmem); EXIT; } static int lov_lock_enqueue_wait(const struct lu_env *env, struct lov_lock *lck, struct cl_lock *sublock) { struct cl_lock *lock = lck->lls_cl.cls_lock; int result; ENTRY; LASSERT(cl_lock_is_mutexed(lock)); cl_lock_mutex_put(env, lock); result = cl_lock_enqueue_wait(env, sublock, 0); cl_lock_mutex_get(env, lock); RETURN(result ?: CLO_REPEAT); } /** * Tries to advance a state machine of a given sub-lock toward enqueuing of * the top-lock. * * \retval 0 if state-transition can proceed * \retval -ve otherwise. */ static int lov_lock_enqueue_one(const struct lu_env *env, struct lov_lock *lck, struct cl_lock *sublock, struct cl_io *io, __u32 enqflags, int last) { int result; ENTRY; /* first, try to enqueue a sub-lock ... */ result = cl_enqueue_try(env, sublock, io, enqflags); if ((sublock->cll_state == CLS_ENQUEUED) && !(enqflags & CEF_AGL)) { /* if it is enqueued, try to `wait' on it---maybe it's already * granted */ result = cl_wait_try(env, sublock); if (result == CLO_REENQUEUED) result = CLO_WAIT; } /* * If CEF_ASYNC flag is set, then all sub-locks can be enqueued in * parallel, otherwise---enqueue has to wait until sub-lock is granted * before proceeding to the next one. */ if ((result == CLO_WAIT) && (sublock->cll_state <= CLS_HELD) && (enqflags & CEF_ASYNC) && (!last || (enqflags & CEF_AGL))) result = 0; RETURN(result); } /** * Helper function for lov_lock_enqueue() that creates missing sub-lock. */ static int lov_sublock_fill(const struct lu_env *env, struct cl_lock *parent, struct cl_io *io, struct lov_lock *lck, int idx) { struct lov_lock_link *link; struct cl_lock *sublock; int result; LASSERT(parent->cll_depth == 1); cl_lock_mutex_put(env, parent); sublock = lov_sublock_alloc(env, io, lck, idx, &link); if (!IS_ERR(sublock)) cl_lock_mutex_get(env, sublock); cl_lock_mutex_get(env, parent); if (!IS_ERR(sublock)) { cl_lock_get_trust(sublock); if (parent->cll_state == CLS_QUEUING && lck->lls_sub[idx].sub_lock == NULL) { lov_sublock_adopt(env, lck, sublock, idx, link); } else { OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem); /* other thread allocated sub-lock, or enqueue is no * longer going on */ cl_lock_mutex_put(env, parent); cl_lock_unhold(env, sublock, "lov-parent", parent); cl_lock_mutex_get(env, parent); } cl_lock_mutex_put(env, sublock); cl_lock_put(env, sublock); result = CLO_REPEAT; } else result = PTR_ERR(sublock); return result; } /** * Implementation of cl_lock_operations::clo_enqueue() for lov layer. This * function is rather subtle, as it enqueues top-lock (i.e., advances top-lock * state machine from CLS_QUEUING to CLS_ENQUEUED states) by juggling sub-lock * state machines in the face of sub-locks sharing (by multiple top-locks), * and concurrent sub-lock cancellations. */ static int lov_lock_enqueue(const struct lu_env *env, const struct cl_lock_slice *slice, struct cl_io *io, __u32 enqflags) { struct cl_lock *lock = slice->cls_lock; struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, lock); int i; int result; enum cl_lock_state minstate; ENTRY; for (result = 0, minstate = CLS_FREEING, i = 0; i < lck->lls_nr; ++i) { int rc; struct lovsub_lock *sub; struct lov_lock_sub *lls; struct cl_lock *sublock; struct lov_sublock_env *subenv; if (lock->cll_state != CLS_QUEUING) { /* * Lock might have left QUEUING state if previous * iteration released its mutex. Stop enqueing in this * case and let the upper layer to decide what to do. */ LASSERT(i > 0 && result != 0); break; } lls = &lck->lls_sub[i]; sub = lls->sub_lock; /* * Sub-lock might have been canceled, while top-lock was * cached. */ if (sub == NULL) { result = lov_sublock_fill(env, lock, io, lck, i); /* lov_sublock_fill() released @lock mutex, * restart. */ break; } sublock = sub->lss_cl.cls_lock; rc = lov_sublock_lock(env, lck, lls, closure, &subenv); if (rc == 0) { lov_sublock_hold(env, lck, i); rc = lov_lock_enqueue_one(subenv->lse_env, lck, sublock, subenv->lse_io, enqflags, i == lck->lls_nr - 1); minstate = min(minstate, sublock->cll_state); if (rc == CLO_WAIT) { switch (sublock->cll_state) { case CLS_QUEUING: /* take recursive mutex, the lock is * released in lov_lock_enqueue_wait. */ cl_lock_mutex_get(env, sublock); lov_sublock_unlock(env, sub, closure, subenv); rc = lov_lock_enqueue_wait(env, lck, sublock); break; case CLS_CACHED: cl_lock_get(sublock); /* take recursive mutex of sublock */ cl_lock_mutex_get(env, sublock); /* need to release all locks in closure * otherwise it may deadlock. LU-2683.*/ lov_sublock_unlock(env, sub, closure, subenv); /* sublock and parent are held. */ rc = lov_sublock_release(env, lck, i, 1, rc); cl_lock_mutex_put(env, sublock); cl_lock_put(env, sublock); break; default: lov_sublock_unlock(env, sub, closure, subenv); break; } } else { LASSERT(sublock->cll_conflict == NULL); lov_sublock_unlock(env, sub, closure, subenv); } } result = lov_subresult(result, rc); if (result != 0) break; } cl_lock_closure_fini(closure); RETURN(result ?: minstate >= CLS_ENQUEUED ? 0 : CLO_WAIT); } static int lov_lock_unuse(const struct lu_env *env, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock); int i; int result; ENTRY; for (result = 0, i = 0; i < lck->lls_nr; ++i) { int rc; struct lovsub_lock *sub; struct cl_lock *sublock; struct lov_lock_sub *lls; struct lov_sublock_env *subenv; /* top-lock state cannot change concurrently, because single * thread (one that released the last hold) carries unlocking * to the completion. */ LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT); lls = &lck->lls_sub[i]; sub = lls->sub_lock; if (sub == NULL) continue; sublock = sub->lss_cl.cls_lock; rc = lov_sublock_lock(env, lck, lls, closure, &subenv); if (rc == 0) { if (lls->sub_flags & LSF_HELD) { LASSERT(sublock->cll_state == CLS_HELD || sublock->cll_state == CLS_ENQUEUED); rc = cl_unuse_try(subenv->lse_env, sublock); rc = lov_sublock_release(env, lck, i, 0, rc); } lov_sublock_unlock(env, sub, closure, subenv); } result = lov_subresult(result, rc); } if (result == 0 && lck->lls_cancel_race) { lck->lls_cancel_race = 0; result = -ESTALE; } cl_lock_closure_fini(closure); RETURN(result); } static void lov_lock_cancel(const struct lu_env *env, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock); int i; int result; ENTRY; for (result = 0, i = 0; i < lck->lls_nr; ++i) { int rc; struct lovsub_lock *sub; struct cl_lock *sublock; struct lov_lock_sub *lls; struct lov_sublock_env *subenv; /* top-lock state cannot change concurrently, because single * thread (one that released the last hold) carries unlocking * to the completion. */ lls = &lck->lls_sub[i]; sub = lls->sub_lock; if (sub == NULL) continue; sublock = sub->lss_cl.cls_lock; rc = lov_sublock_lock(env, lck, lls, closure, &subenv); if (rc == 0) { if (!(lls->sub_flags & LSF_HELD)) { lov_sublock_unlock(env, sub, closure, subenv); continue; } switch(sublock->cll_state) { case CLS_HELD: rc = cl_unuse_try(subenv->lse_env, sublock); lov_sublock_release(env, lck, i, 0, 0); break; default: lov_sublock_release(env, lck, i, 1, 0); break; } lov_sublock_unlock(env, sub, closure, subenv); } if (rc == CLO_REPEAT) { --i; continue; } result = lov_subresult(result, rc); } if (result) CL_LOCK_DEBUG(D_ERROR, env, slice->cls_lock, "lov_lock_cancel fails with %d.\n", result); cl_lock_closure_fini(closure); } static int lov_lock_wait(const struct lu_env *env, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock); enum cl_lock_state minstate; int reenqueued; int result; int i; ENTRY; again: for (result = 0, minstate = CLS_FREEING, i = 0, reenqueued = 0; i < lck->lls_nr; ++i) { int rc; struct lovsub_lock *sub; struct cl_lock *sublock; struct lov_lock_sub *lls; struct lov_sublock_env *subenv; lls = &lck->lls_sub[i]; sub = lls->sub_lock; LASSERT(sub != NULL); sublock = sub->lss_cl.cls_lock; rc = lov_sublock_lock(env, lck, lls, closure, &subenv); if (rc == 0) { LASSERT(sublock->cll_state >= CLS_ENQUEUED); if (sublock->cll_state < CLS_HELD) rc = cl_wait_try(env, sublock); minstate = min(minstate, sublock->cll_state); lov_sublock_unlock(env, sub, closure, subenv); } if (rc == CLO_REENQUEUED) { reenqueued++; rc = 0; } result = lov_subresult(result, rc); if (result != 0) break; } /* Each sublock only can be reenqueued once, so will not loop for * ever. */ if (result == 0 && reenqueued != 0) goto again; cl_lock_closure_fini(closure); RETURN(result ?: minstate >= CLS_HELD ? 0 : CLO_WAIT); } static int lov_lock_use(const struct lu_env *env, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock); int result; int i; LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT); ENTRY; for (result = 0, i = 0; i < lck->lls_nr; ++i) { int rc; struct lovsub_lock *sub; struct cl_lock *sublock; struct lov_lock_sub *lls; struct lov_sublock_env *subenv; LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT); lls = &lck->lls_sub[i]; sub = lls->sub_lock; if (sub == NULL) { /* * Sub-lock might have been canceled, while top-lock was * cached. */ result = -ESTALE; break; } sublock = sub->lss_cl.cls_lock; rc = lov_sublock_lock(env, lck, lls, closure, &subenv); if (rc == 0) { LASSERT(sublock->cll_state != CLS_FREEING); lov_sublock_hold(env, lck, i); if (sublock->cll_state == CLS_CACHED) { rc = cl_use_try(subenv->lse_env, sublock, 0); if (rc != 0) rc = lov_sublock_release(env, lck, i, 1, rc); } else if (sublock->cll_state == CLS_NEW) { /* Sub-lock might have been canceled, while * top-lock was cached. */ result = -ESTALE; lov_sublock_release(env, lck, i, 1, result); } lov_sublock_unlock(env, sub, closure, subenv); } result = lov_subresult(result, rc); if (result != 0) break; } if (lck->lls_cancel_race) { /* * If there is unlocking happened at the same time, then * sublock_lock state should be FREEING, and lov_sublock_lock * should return CLO_REPEAT. In this case, it should return * ESTALE, and up layer should reset the lock state to be NEW. */ lck->lls_cancel_race = 0; LASSERT(result != 0); result = -ESTALE; } cl_lock_closure_fini(closure); RETURN(result); } #if 0 static int lock_lock_multi_match() { struct cl_lock *lock = slice->cls_lock; struct cl_lock_descr *subneed = &lov_env_info(env)->lti_ldescr; struct lov_object *loo = cl2lov(lov->lls_cl.cls_obj); struct lov_layout_raid0 *r0 = lov_r0(loo); struct lov_lock_sub *sub; struct cl_object *subobj; obd_off fstart; obd_off fend; obd_off start; obd_off end; int i; fstart = cl_offset(need->cld_obj, need->cld_start); fend = cl_offset(need->cld_obj, need->cld_end + 1) - 1; subneed->cld_mode = need->cld_mode; cl_lock_mutex_get(env, lock); for (i = 0; i < lov->lls_nr; ++i) { sub = &lov->lls_sub[i]; if (sub->sub_lock == NULL) continue; subobj = sub->sub_descr.cld_obj; if (!lov_stripe_intersects(loo->lo_lsm, sub->sub_stripe, fstart, fend, &start, &end)) continue; subneed->cld_start = cl_index(subobj, start); subneed->cld_end = cl_index(subobj, end); subneed->cld_obj = subobj; if (!cl_lock_ext_match(&sub->sub_got, subneed)) { result = 0; break; } } cl_lock_mutex_put(env, lock); } #endif /** * Check if the extent region \a descr is covered by \a child against the * specific \a stripe. */ static int lov_lock_stripe_is_matching(const struct lu_env *env, struct lov_object *lov, int stripe, const struct cl_lock_descr *child, const struct cl_lock_descr *descr) { struct lov_stripe_md *lsm = lov->lo_lsm; obd_off start; obd_off end; int result; if (lov_r0(lov)->lo_nr == 1) return cl_lock_ext_match(child, descr); /* * For a multi-stripes object: * - make sure the descr only covers child's stripe, and * - check if extent is matching. */ start = cl_offset(&lov->lo_cl, descr->cld_start); end = cl_offset(&lov->lo_cl, descr->cld_end + 1) - 1; result = end - start <= lsm->lsm_stripe_size && stripe == lov_stripe_number(lsm, start) && stripe == lov_stripe_number(lsm, end); if (result) { struct cl_lock_descr *subd = &lov_env_info(env)->lti_ldescr; obd_off sub_start; obd_off sub_end; subd->cld_obj = NULL; /* don't need sub object at all */ subd->cld_mode = descr->cld_mode; subd->cld_gid = descr->cld_gid; result = lov_stripe_intersects(lsm, stripe, start, end, &sub_start, &sub_end); LASSERT(result); subd->cld_start = cl_index(child->cld_obj, sub_start); subd->cld_end = cl_index(child->cld_obj, sub_end); result = cl_lock_ext_match(child, subd); } return result; } /** * An implementation of cl_lock_operations::clo_fits_into() method. * * Checks whether a lock (given by \a slice) is suitable for \a * io. Multi-stripe locks can be used only for "quick" io, like truncate, or * O_APPEND write. * * \see ccc_lock_fits_into(). */ static int lov_lock_fits_into(const struct lu_env *env, const struct cl_lock_slice *slice, const struct cl_lock_descr *need, const struct cl_io *io) { struct lov_lock *lov = cl2lov_lock(slice); struct lov_object *obj = cl2lov(slice->cls_obj); int result; LASSERT(cl_object_same(need->cld_obj, slice->cls_obj)); LASSERT(lov->lls_nr > 0); ENTRY; /* for top lock, it's necessary to match enq flags otherwise it will * run into problem if a sublock is missing and reenqueue. */ if (need->cld_enq_flags != lov->lls_orig.cld_enq_flags) return 0; if (lov->lls_ever_canceled) return 0; if (need->cld_mode == CLM_GROUP) /* * always allow to match group lock. */ result = cl_lock_ext_match(&lov->lls_orig, need); else if (lov->lls_nr == 1) { struct cl_lock_descr *got = &lov->lls_sub[0].sub_got; result = lov_lock_stripe_is_matching(env, cl2lov(slice->cls_obj), lov->lls_sub[0].sub_stripe, got, need); } else if (io->ci_type != CIT_SETATTR && io->ci_type != CIT_MISC && !cl_io_is_append(io) && need->cld_mode != CLM_PHANTOM) /* * Multi-stripe locks are only suitable for `quick' IO and for * glimpse. */ result = 0; else /* * Most general case: multi-stripe existing lock, and * (potentially) multi-stripe @need lock. Check that @need is * covered by @lov's sub-locks. * * For now, ignore lock expansions made by the server, and * match against original lock extent. */ result = cl_lock_ext_match(&lov->lls_orig, need); CDEBUG(D_DLMTRACE, DDESCR"/"DDESCR" %d %d/%d: %d\n", PDESCR(&lov->lls_orig), PDESCR(&lov->lls_sub[0].sub_got), lov->lls_sub[0].sub_stripe, lov->lls_nr, lov_r0(obj)->lo_nr, result); RETURN(result); } void lov_lock_unlink(const struct lu_env *env, struct lov_lock_link *link, struct lovsub_lock *sub) { struct lov_lock *lck = link->lll_super; struct cl_lock *parent = lck->lls_cl.cls_lock; LASSERT(cl_lock_is_mutexed(parent)); LASSERT(cl_lock_is_mutexed(sub->lss_cl.cls_lock)); ENTRY; cfs_list_del_init(&link->lll_list); LASSERT(lck->lls_sub[link->lll_idx].sub_lock == sub); /* yank this sub-lock from parent's array */ lck->lls_sub[link->lll_idx].sub_lock = NULL; LASSERT(lck->lls_nr_filled > 0); lck->lls_nr_filled--; lu_ref_del(&parent->cll_reference, "lov-child", sub->lss_cl.cls_lock); cl_lock_put(env, parent); OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem); EXIT; } struct lov_lock_link *lov_lock_link_find(const struct lu_env *env, struct lov_lock *lck, struct lovsub_lock *sub) { struct lov_lock_link *scan; LASSERT(cl_lock_is_mutexed(sub->lss_cl.cls_lock)); ENTRY; cfs_list_for_each_entry(scan, &sub->lss_parents, lll_list) { if (scan->lll_super == lck) RETURN(scan); } RETURN(NULL); } /** * An implementation of cl_lock_operations::clo_delete() method. This is * invoked for "top-to-bottom" delete, when lock destruction starts from the * top-lock, e.g., as a result of inode destruction. * * Unlinks top-lock from all its sub-locks. Sub-locks are not deleted there: * this is done separately elsewhere: * * - for inode destruction, lov_object_delete() calls cl_object_kill() for * each sub-object, purging its locks; * * - in other cases (e.g., a fatal error with a top-lock) sub-locks are * left in the cache. */ static void lov_lock_delete(const struct lu_env *env, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock); struct lov_lock_link *link; int rc; int i; LASSERT(slice->cls_lock->cll_state == CLS_FREEING); ENTRY; for (i = 0; i < lck->lls_nr; ++i) { struct lov_lock_sub *lls = &lck->lls_sub[i]; struct lovsub_lock *lsl = lls->sub_lock; if (lsl == NULL) /* already removed */ continue; rc = lov_sublock_lock(env, lck, lls, closure, NULL); if (rc == CLO_REPEAT) { --i; continue; } LASSERT(rc == 0); LASSERT(lsl->lss_cl.cls_lock->cll_state < CLS_FREEING); if (lls->sub_flags & LSF_HELD) lov_sublock_release(env, lck, i, 1, 0); link = lov_lock_link_find(env, lck, lsl); LASSERT(link != NULL); lov_lock_unlink(env, link, lsl); LASSERT(lck->lls_sub[i].sub_lock == NULL); lov_sublock_unlock(env, lsl, closure, NULL); } cl_lock_closure_fini(closure); EXIT; } static int lov_lock_print(const struct lu_env *env, void *cookie, lu_printer_t p, const struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); int i; (*p)(env, cookie, "%d\n", lck->lls_nr); for (i = 0; i < lck->lls_nr; ++i) { struct lov_lock_sub *sub; sub = &lck->lls_sub[i]; (*p)(env, cookie, " %d %x: ", i, sub->sub_flags); if (sub->sub_lock != NULL) cl_lock_print(env, cookie, p, sub->sub_lock->lss_cl.cls_lock); else (*p)(env, cookie, "---\n"); } return 0; } static const struct cl_lock_operations lov_lock_ops = { .clo_fini = lov_lock_fini, .clo_enqueue = lov_lock_enqueue, .clo_wait = lov_lock_wait, .clo_use = lov_lock_use, .clo_unuse = lov_lock_unuse, .clo_cancel = lov_lock_cancel, .clo_fits_into = lov_lock_fits_into, .clo_delete = lov_lock_delete, .clo_print = lov_lock_print }; int lov_lock_init_raid0(const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io) { struct lov_lock *lck; int result; ENTRY; OBD_SLAB_ALLOC_PTR_GFP(lck, lov_lock_kmem, __GFP_IO); if (lck != NULL) { cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_lock_ops); result = lov_lock_sub_init(env, lck, io); } else result = -ENOMEM; RETURN(result); } static void lov_empty_lock_fini(const struct lu_env *env, struct cl_lock_slice *slice) { struct lov_lock *lck = cl2lov_lock(slice); OBD_SLAB_FREE_PTR(lck, lov_lock_kmem); } static int lov_empty_lock_print(const struct lu_env *env, void *cookie, lu_printer_t p, const struct cl_lock_slice *slice) { (*p)(env, cookie, "empty\n"); return 0; } /* XXX: more methods will be added later. */ static const struct cl_lock_operations lov_empty_lock_ops = { .clo_fini = lov_empty_lock_fini, .clo_print = lov_empty_lock_print }; int lov_lock_init_empty(const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io) { struct lov_lock *lck; int result = -ENOMEM; ENTRY; OBD_SLAB_ALLOC_PTR_GFP(lck, lov_lock_kmem, __GFP_IO); if (lck != NULL) { cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_empty_lock_ops); lck->lls_orig = lock->cll_descr; result = 0; } RETURN(result); } static struct cl_lock_closure *lov_closure_get(const struct lu_env *env, struct cl_lock *parent) { struct cl_lock_closure *closure; closure = &lov_env_info(env)->lti_closure; LASSERT(cfs_list_empty(&closure->clc_list)); cl_lock_closure_init(env, closure, parent, 1); return closure; } /** @} lov */