diff options
author | avg <avg@FreeBSD.org> | 2016-12-24 14:25:25 +0000 |
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committer | avg <avg@FreeBSD.org> | 2016-12-24 14:25:25 +0000 |
commit | 3d162939c0984677424451cb3460555cbea11657 (patch) | |
tree | ae8b22fba80ad7078fddce787754f16baabb94fc /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c | |
parent | 2e70302a11d1117fac0b4e0976f4afd4ea5f012f (diff) | |
download | FreeBSD-src-3d162939c0984677424451cb3460555cbea11657.zip FreeBSD-src-3d162939c0984677424451cb3460555cbea11657.tar.gz |
MFC r309250: MFV r309249: 3821 Race in rollback, zil close, and zil flush
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c')
-rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c | 58 |
1 files changed, 52 insertions, 6 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c index 799df31..0a7affb 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c @@ -20,8 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2015 by Delphix. All rights reserved. - * Copyright (c) 2011, 2014 by Delphix. All rights reserved. + * Copyright (c) 2011, 2016 by Delphix. All rights reserved. * Copyright (c) 2014 Integros [integros.com] */ @@ -495,6 +494,27 @@ 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) { @@ -1058,8 +1078,6 @@ 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( @@ -1392,6 +1410,11 @@ 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]; @@ -1401,6 +1424,16 @@ 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; @@ -1426,6 +1459,10 @@ 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]; @@ -1497,8 +1534,14 @@ zil_commit_writer(zilog_t *zilog) DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); while (itx = list_head(&zilog->zl_itx_commit_list)) { 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); list_remove(&zilog->zl_itx_commit_list, itx); @@ -1815,7 +1858,10 @@ zil_close(zilog_t *zilog) mutex_exit(&zilog->zl_lock); if (txg) txg_wait_synced(zilog->zl_dmu_pool, txg); - ASSERT(!zilog_is_dirty(zilog)); + + if (zilog_is_dirty(zilog)) + zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog, txg); + VERIFY(!zilog_is_dirty(zilog)); taskq_destroy(zilog->zl_clean_taskq); zilog->zl_clean_taskq = NULL; |