diff options
| -rw-r--r-- | module/zfs/dsl_pool.c | 9 | ||||
| -rw-r--r-- | module/zfs/spa.c | 9 | ||||
| -rw-r--r-- | module/zfs/zil.c | 60 |
3 files changed, 70 insertions, 8 deletions
diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c index 2386484c8..1bc73ebc7 100644 --- a/module/zfs/dsl_pool.c +++ b/module/zfs/dsl_pool.c @@ -615,9 +615,16 @@ dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg) { zilog_t *zilog; - while ((zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg))) { + while ((zilog = txg_list_head(&dp->dp_dirty_zilogs, txg))) { dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); + /* + * We don't remove the zilog from the dp_dirty_zilogs + * list until after we've cleaned it. This ensures that + * callers of zilog_is_dirty() receive an accurate + * answer when they are racing with the spa sync thread. + */ zil_clean(zilog, txg); + (void) txg_list_remove_this(&dp->dp_dirty_zilogs, zilog, txg); ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg)); dmu_buf_rele(ds->ds_dbuf, zilog); } diff --git a/module/zfs/spa.c b/module/zfs/spa.c index d632d635e..f573fe0d7 100644 --- a/module/zfs/spa.c +++ b/module/zfs/spa.c @@ -6749,8 +6749,6 @@ spa_sync(spa_t *spa, uint64_t txg) spa->spa_config_syncing = NULL; } - spa->spa_ubsync = spa->spa_uberblock; - dsl_pool_sync_done(dp, txg); mutex_enter(&spa->spa_alloc_lock); @@ -6775,6 +6773,13 @@ spa_sync(spa_t *spa, uint64_t txg) spa->spa_sync_pass = 0; + /* + * Update the last synced uberblock here. We want to do this at + * the end of spa_sync() so that consumers of spa_last_synced_txg() + * will be guaranteed that all the processing associated with + * that txg has been completed. + */ + spa->spa_ubsync = spa->spa_uberblock; spa_config_exit(spa, SCL_CONFIG, FTAG); spa_handle_ignored_writes(spa); diff --git a/module/zfs/zil.c b/module/zfs/zil.c index 10ea12cd7..e745ac253 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -20,7 +20,8 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2015 by Delphix. All rights reserved. + * Copyright (c) 2011, 2016 by Delphix. All rights reserved. + * Copyright (c) 2014 Integros [integros.com] */ /* Portions Copyright 2010 Robert Milkowski */ @@ -504,6 +505,27 @@ zilog_dirty(zilog_t *zilog, uint64_t txg) } } +/* + * Determine if the zil is dirty in the specified txg. Callers wanting to + * ensure that the dirty state does not change must hold the itxg_lock for + * the specified txg. Holding the lock will ensure that the zil cannot be + * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current + * state. + */ +boolean_t +zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) +{ + dsl_pool_t *dp = zilog->zl_dmu_pool; + + if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) + return (B_TRUE); + return (B_FALSE); +} + +/* + * Determine if the zil is dirty. The zil is considered dirty if it has + * any pending itx records that have not been cleaned by zil_clean(). + */ boolean_t zilog_is_dirty(zilog_t *zilog) { @@ -1091,8 +1113,6 @@ zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) return (NULL); ASSERT(lwb->lwb_buf != NULL); - ASSERT(zilog_is_dirty(zilog) || - spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) dlen = P2ROUNDUP_TYPED( @@ -1339,6 +1359,8 @@ zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) * this itxg. Save the itxs for release below. * This should be rare. */ + zfs_dbgmsg("zil_itx_assign: missed itx cleanup for " + "txg %llu", itxg->itxg_txg); atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); itxg->itxg_sod = 0; clean = itxg->itxg_itxs; @@ -1439,6 +1461,11 @@ zil_get_commit_list(zilog_t *zilog) else otxg = spa_last_synced_txg(zilog->zl_spa) + 1; + /* + * This is inherently racy, since there is nothing to prevent + * the last synced txg from changing. That's okay since we'll + * only commit things in the future. + */ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; @@ -1448,6 +1475,16 @@ zil_get_commit_list(zilog_t *zilog) continue; } + /* + * If we're adding itx records to the zl_itx_commit_list, + * then the zil better be dirty in this "txg". We can assert + * that here since we're holding the itxg_lock which will + * prevent spa_sync from cleaning it. Once we add the itxs + * to the zl_itx_commit_list we must commit it to disk even + * if it's unnecessary (i.e. the txg was synced). + */ + ASSERT(zilog_is_dirty_in_txg(zilog, txg) || + spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); push_sod += itxg->itxg_sod; itxg->itxg_sod = 0; @@ -1473,6 +1510,10 @@ zil_async_to_sync(zilog_t *zilog, uint64_t foid) else otxg = spa_last_synced_txg(zilog->zl_spa) + 1; + /* + * This is inherently racy, since there is nothing to prevent + * the last synced txg from changing. + */ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; @@ -1545,8 +1586,14 @@ zil_commit_writer(zilog_t *zilog) for (itx = list_head(&zilog->zl_itx_commit_list); itx != NULL; itx = list_next(&zilog->zl_itx_commit_list, itx)) { txg = itx->itx_lr.lrc_txg; - ASSERT(txg); + ASSERT3U(txg, !=, 0); + /* + * This is inherently racy and may result in us writing + * out a log block for a txg that was just synced. This is + * ok since we'll end cleaning up that log block the next + * time we call zil_sync(). + */ if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) lwb = zil_lwb_commit(zilog, itx, lwb); } @@ -1907,8 +1954,11 @@ zil_close(zilog_t *zilog) mutex_exit(&zilog->zl_lock); if (txg) txg_wait_synced(zilog->zl_dmu_pool, txg); + + if (zilog_is_dirty(zilog)) + zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog, txg); if (txg < spa_freeze_txg(zilog->zl_spa)) - ASSERT(!zilog_is_dirty(zilog)); + VERIFY(!zilog_is_dirty(zilog)); taskq_destroy(zilog->zl_clean_taskq); zilog->zl_clean_taskq = NULL; |