X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosc%2Fosc_lock.c;h=8cb79b1d1b4340d297a7db1ec8509f62777ffe0c;hp=1b5f4118948bae760d27a0038c8072038e63f677;hb=51459371a2e146d01f9d2ef27fdf75d77639266f;hpb=7877f9ebf7cde785319f92e4a1fd033def11f23a diff --git a/lustre/osc/osc_lock.c b/lustre/osc/osc_lock.c index 1b5f411..8cb79b1 100644 --- a/lustre/osc/osc_lock.c +++ b/lustre/osc/osc_lock.c @@ -167,15 +167,28 @@ static void osc_lock_detach(const struct lu_env *env, struct osc_lock *olck) unlock_res_and_lock(dlmlock); /* release a reference taken in osc_lock_upcall0(). */ + LASSERT(olck->ols_has_ref); lu_ref_del(&dlmlock->l_reference, "osc_lock", olck); LDLM_LOCK_RELEASE(dlmlock); + olck->ols_has_ref = 0; +} + +static int osc_lock_unhold(struct osc_lock *ols) +{ + int result = 0; + + if (ols->ols_hold) { + ols->ols_hold = 0; + result = osc_cancel_base(&ols->ols_handle, + ols->ols_einfo.ei_mode); + } + return result; } static int osc_lock_unuse(const struct lu_env *env, const struct cl_lock_slice *slice) { struct osc_lock *ols = cl2osc_lock(slice); - int result; LASSERT(ols->ols_state == OLS_GRANTED || ols->ols_state == OLS_UPCALL_RECEIVED); @@ -193,10 +206,7 @@ static int osc_lock_unuse(const struct lu_env *env, * e.g., for liblustre) sees that lock is released. */ ols->ols_state = OLS_RELEASED; - ols->ols_hold = 0; - result = osc_cancel_base(&ols->ols_handle, ols->ols_einfo.ei_mode); - ols->ols_has_ref = 0; - return result; + return osc_lock_unhold(ols); } static void osc_lock_fini(const struct lu_env *env, @@ -211,8 +221,7 @@ static void osc_lock_fini(const struct lu_env *env, * to the lock), before reply from a server was received. In this case * lock is destroyed immediately after upcall. */ - if (ols->ols_hold) - osc_lock_unuse(env, slice); + osc_lock_unhold(ols); LASSERT(ols->ols_lock == NULL); OBD_SLAB_FREE_PTR(ols, osc_lock_kmem); @@ -462,11 +471,12 @@ static void osc_lock_upcall0(const struct lu_env *env, struct osc_lock *olck) * this. */ ldlm_lock_addref(&olck->ols_handle, olck->ols_einfo.ei_mode); - olck->ols_hold = olck->ols_has_ref = 1; + olck->ols_hold = 1; /* lock reference taken by ldlm_handle2lock_long() is owned by * osc_lock and released in osc_lock_detach() */ lu_ref_add(&dlmlock->l_reference, "osc_lock", olck); + olck->ols_has_ref = 1; } /** @@ -569,12 +579,11 @@ static void osc_lock_blocking(const struct lu_env *env, CLASSERT(OLS_BLOCKED < OLS_CANCELLED); LASSERT(!osc_lock_is_lockless(olck)); - if (olck->ols_hold) - /* - * Lock might be still addref-ed here, if e.g., blocking ast - * is sent for a failed lock. - */ - osc_lock_unuse(env, &olck->ols_cl); + /* + * Lock might be still addref-ed here, if e.g., blocking ast + * is sent for a failed lock. + */ + osc_lock_unhold(olck); if (blocking && olck->ols_state < OLS_BLOCKED) /* @@ -771,7 +780,7 @@ static int osc_ldlm_completion_ast(struct ldlm_lock *dlmlock, LASSERT(dlmlock->l_lvb_data != NULL); lock_res_and_lock(dlmlock); olck->ols_lvb = *(struct ost_lvb *)dlmlock->l_lvb_data; - if (olck->ols_lock == NULL) + if (olck->ols_lock == NULL) { /* * upcall (osc_lock_upcall()) hasn't yet been * called. Do nothing now, upcall will bind @@ -781,12 +790,17 @@ static int osc_ldlm_completion_ast(struct ldlm_lock *dlmlock, * and ldlm_lock are always bound when * osc_lock is in OLS_GRANTED state. */ - ; - else if (dlmlock->l_granted_mode != LCK_MINMODE) + } else if (dlmlock->l_granted_mode == + dlmlock->l_req_mode) { osc_lock_granted(env, olck, dlmlock, dlmrc); + } unlock_res_and_lock(dlmlock); - if (dlmrc != 0) + + if (dlmrc != 0) { + CL_LOCK_DEBUG(D_ERROR, env, lock, + "dlmlock returned %d\n", dlmrc); cl_lock_error(env, lock, dlmrc); + } cl_lock_mutex_put(env, lock); osc_ast_data_put(env, olck); result = 0; @@ -936,86 +950,6 @@ static void osc_lock_build_einfo(const struct lu_env *env, einfo->ei_cbdata = lock; /* value to be put into ->l_ast_data */ } -static int osc_lock_delete0(struct cl_lock *conflict) -{ - struct cl_env_nest nest; - struct lu_env *env; - int rc = 0; - - env = cl_env_nested_get(&nest); - if (!IS_ERR(env)) { - cl_lock_delete(env, conflict); - cl_env_nested_put(&nest, env); - } else - rc = PTR_ERR(env); - return rc; -} -/** - * Cancels \a conflict lock and waits until it reached CLS_FREEING state. This - * is called as a part of enqueuing to cancel conflicting locks early. - * - * \retval 0: success, \a conflict was cancelled and destroyed. - * - * \retval CLO_REPEAT: \a conflict was cancelled, but \a lock mutex was - * released in the process. Repeat enqueing. - * - * \retval -EWOULDBLOCK: \a conflict cannot be cancelled immediately, and - * either \a lock is non-blocking, or current thread - * holds other locks, that prevent it from waiting - * for cancel to complete. - * - * \retval -ve: other error, including -EINTR. - * - */ -static int osc_lock_cancel_wait(const struct lu_env *env, struct cl_lock *lock, - struct cl_lock *conflict, int canwait) -{ - int rc; - - LASSERT(cl_lock_is_mutexed(lock)); - LASSERT(cl_lock_is_mutexed(conflict)); - - rc = 0; - if (conflict->cll_state != CLS_FREEING) { - cl_lock_cancel(env, conflict); - rc = osc_lock_delete0(conflict); - if (rc) - return rc; - if (conflict->cll_flags & (CLF_CANCELPEND|CLF_DOOMED)) { - rc = -EWOULDBLOCK; - if (cl_lock_nr_mutexed(env) > 2) - /* - * If mutices of locks other than @lock and - * @scan are held by the current thread, it - * cannot wait on @scan state change in a - * dead-lock safe matter, so simply skip early - * cancellation in this case. - * - * This means that early cancellation doesn't - * work when there is even slight mutex - * contention, as top-lock's mutex is usually - * held at this time. - */ - ; - else if (canwait) { - /* Waiting for @scan to be destroyed */ - cl_lock_mutex_put(env, lock); - do { - rc = cl_lock_state_wait(env, conflict); - } while (!rc && - conflict->cll_state < CLS_FREEING); - /* mutex was released, repeat enqueue. */ - rc = rc ?: CLO_REPEAT; - cl_lock_mutex_get(env, lock); - } - } - LASSERT(ergo(!rc, conflict->cll_state == CLS_FREEING)); - CDEBUG(D_INFO, "lock %p was %s freed now, rc (%d)\n", - conflict, rc ? "not":"", rc); - } - return rc; -} - /** * Determine if the lock should be converted into a lockless lock. * @@ -1071,6 +1005,28 @@ static void osc_lock_to_lockless(const struct lu_env *env, LASSERT(ergo(ols->ols_glimpse, !osc_lock_is_lockless(ols))); } +static int osc_lock_compatible(const struct osc_lock *qing, + const struct osc_lock *qed) +{ + enum cl_lock_mode qing_mode; + enum cl_lock_mode qed_mode; + + qing_mode = qing->ols_cl.cls_lock->cll_descr.cld_mode; + if (qed->ols_glimpse && + (qed->ols_state >= OLS_UPCALL_RECEIVED || qing_mode == CLM_READ)) + return 1; + + qed_mode = qed->ols_cl.cls_lock->cll_descr.cld_mode; + return ((qing_mode == CLM_READ) && (qed_mode == CLM_READ)); +} + +#ifndef list_for_each_entry_continue +#define list_for_each_entry_continue(pos, head, member) \ + for (pos = list_entry(pos->member.next, typeof(*pos), member); \ + prefetch(pos->member.next), &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) +#endif + /** * Cancel all conflicting locks and wait for them to be destroyed. * @@ -1088,36 +1044,29 @@ static int osc_lock_enqueue_wait(const struct lu_env *env, struct cl_lock *lock = olck->ols_cl.cls_lock; struct cl_lock_descr *descr = &lock->cll_descr; struct cl_object_header *hdr = cl_object_header(descr->cld_obj); - struct cl_lock_closure *closure = &osc_env_info(env)->oti_closure; - struct cl_lock *scan; - struct cl_lock *temp; + struct cl_lock *scan = lock; + struct cl_lock *conflict= NULL; int lockless = osc_lock_is_lockless(olck); int rc = 0; - int canwait; - int stop; ENTRY; LASSERT(cl_lock_is_mutexed(lock)); LASSERT(lock->cll_state == CLS_QUEUING); - /* - * XXX This function could be sped up if we had asynchronous - * cancellation. - */ + /* make it enqueue anyway for glimpse lock, because we actually + * don't need to cancel any conflicting locks. */ + if (olck->ols_glimpse) + return 0; - canwait = - !(olck->ols_flags & LDLM_FL_BLOCK_NOWAIT) && - cl_lock_nr_mutexed(env) == 1; - cl_lock_closure_init(env, closure, lock, canwait); spin_lock(&hdr->coh_lock_guard); - list_for_each_entry_safe(scan, temp, &hdr->coh_locks, cll_linkage) { - if (scan == lock) - continue; + list_for_each_entry_continue(scan, &hdr->coh_locks, cll_linkage) { + struct cl_lock_descr *cld = &scan->cll_descr; + const struct osc_lock *scan_ols; if (scan->cll_state < CLS_QUEUING || scan->cll_state == CLS_FREEING || - scan->cll_descr.cld_start > descr->cld_end || - scan->cll_descr.cld_end < descr->cld_start) + cld->cld_start > descr->cld_end || + cld->cld_end < descr->cld_start) continue; /* overlapped and living locks. */ @@ -1129,52 +1078,39 @@ static int osc_lock_enqueue_wait(const struct lu_env *env, continue; } - /* A tricky case for lockless pages: - * We need to cancel the compatible locks if we're enqueuing + scan_ols = osc_lock_at(scan); + + /* We need to cancel the compatible locks if we're enqueuing * a lockless lock, for example: * imagine that client has PR lock on [0, 1000], and thread T0 * is doing lockless IO in [500, 1500] region. Concurrent * thread T1 can see lockless data in [500, 1000], which is - * wrong, because these data are possibly stale. - */ - if (!lockless && cl_lock_compatible(scan, lock)) + * wrong, because these data are possibly stale. */ + if (!lockless && osc_lock_compatible(olck, scan_ols)) continue; /* Now @scan is conflicting with @lock, this means current * thread have to sleep for @scan being destroyed. */ - cl_lock_get_trust(scan); - if (&temp->cll_linkage != &hdr->coh_locks) - cl_lock_get_trust(temp); - spin_unlock(&hdr->coh_lock_guard); - lu_ref_add(&scan->cll_reference, "cancel-wait", lock); - - LASSERT(list_empty(&closure->clc_list)); - rc = cl_lock_closure_build(env, scan, closure); - if (rc == 0) { - rc = osc_lock_cancel_wait(env, lock, scan, canwait); - cl_lock_disclosure(env, closure); - if (rc == -EWOULDBLOCK) - rc = 0; + if (scan_ols->ols_owner == osc_env_io(env)) { + CERROR("DEADLOCK POSSIBLE!\n"); + CL_LOCK_DEBUG(D_ERROR, env, scan, "queued.\n"); + CL_LOCK_DEBUG(D_ERROR, env, lock, "queuing.\n"); + libcfs_debug_dumpstack(NULL); } - if (rc == CLO_REPEAT && !canwait) - /* cannot wait... no early cancellation. */ - rc = 0; - - lu_ref_del(&scan->cll_reference, "cancel-wait", lock); - cl_lock_put(env, scan); - spin_lock(&hdr->coh_lock_guard); - /* - * Lock list could have been modified, while spin-lock was - * released. Check that it is safe to continue. - */ - stop = list_empty(&temp->cll_linkage); - if (&temp->cll_linkage != &hdr->coh_locks) - cl_lock_put(env, temp); - if (stop || rc != 0) - break; + cl_lock_get_trust(scan); + conflict = scan; + break; } spin_unlock(&hdr->coh_lock_guard); - cl_lock_closure_fini(closure); + + if (conflict) { + CDEBUG(D_DLMTRACE, "lock %p is confliced with %p, will wait\n", + lock, conflict); + lu_ref_add(&conflict->cll_reference, "cancel-wait", lock); + LASSERT(lock->cll_conflict == NULL); + lock->cll_conflict = conflict; + rc = CLO_WAIT; + } RETURN(rc); } @@ -1276,12 +1212,12 @@ static int osc_lock_enqueue(const struct lu_env *env, ols->ols_flags |= LDLM_FL_BLOCK_GRANTED; if (ols->ols_flags & LDLM_FL_HAS_INTENT) ols->ols_glimpse = 1; + if (!(enqflags & CEF_MUST)) + /* try to convert this lock to a lockless lock */ + osc_lock_to_lockless(env, ols, (enqflags & CEF_NEVER)); result = osc_lock_enqueue_wait(env, ols); if (result == 0) { - if (!(enqflags & CEF_MUST)) - /* try to convert this lock to a lockless lock */ - osc_lock_to_lockless(env, ols, (enqflags & CEF_NEVER)); if (!osc_lock_is_lockless(ols)) { if (ols->ols_locklessable) ols->ols_flags |= LDLM_FL_DENY_ON_CONTENTION; @@ -1343,13 +1279,14 @@ static int osc_lock_use(const struct lu_env *env, int rc; LASSERT(!olck->ols_hold); + /* * Atomically check for LDLM_FL_CBPENDING and addref a lock if this * flag is not set. This protects us from a concurrent blocking ast. */ rc = ldlm_lock_addref_try(&olck->ols_handle, olck->ols_einfo.ei_mode); if (rc == 0) { - olck->ols_hold = olck->ols_has_ref = 1; + olck->ols_hold = 1; olck->ols_state = OLS_GRANTED; } else { struct cl_lock *lock; @@ -1422,8 +1359,7 @@ static void osc_lock_cancel(const struct lu_env *env, discard = dlmlock->l_flags & LDLM_FL_DISCARD_DATA; result = osc_lock_flush(olck, discard); - if (olck->ols_hold) - osc_lock_unuse(env, slice); + osc_lock_unhold(olck); lock_res_and_lock(dlmlock); /* Now that we're the only user of dlm read/write reference, @@ -1521,8 +1457,7 @@ static void osc_lock_delete(const struct lu_env *env, LINVRNT(osc_lock_invariant(olck)); LINVRNT(!osc_lock_has_pages(olck)); - if (olck->ols_hold) - osc_lock_unuse(env, slice); + osc_lock_unhold(olck); osc_lock_detach(env, olck); } @@ -1562,7 +1497,7 @@ static int osc_lock_print(const struct lu_env *env, void *cookie, /* * XXX print ldlm lock and einfo properly. */ - (*p)(env, cookie, "%p %08x "LPU64" %d %p ", + (*p)(env, cookie, "%p %08x "LPX64" %d %p ", lock->ols_lock, lock->ols_flags, lock->ols_handle.cookie, lock->ols_state, lock->ols_owner); osc_lvb_print(env, cookie, p, &lock->ols_lvb);