From: Prakash Surya Date: Fri, 1 Sep 2017 18:04:26 +0000 (-0700) Subject: OpenZFS 8603 - rename zilog's "zl_writer_lock" to "zl_issuer_lock" X-Git-Tag: zfs-0.8.0-rc1~441 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1b2b0acab54ad4320e9fab9f46612fdb2a71cf87;p=zfs OpenZFS 8603 - rename zilog's "zl_writer_lock" to "zl_issuer_lock" This is a purely cosmetic change. The zilog's "zl_writer_lock" field is being renamed to "zl_issuer_lock" to try and make the code easier to understand; no other changes are made. Authored by: Prakash Surya Reviewed by: C Fraire Approved by: Dan McDonald Reviewed-by: Brian Behlendorf Ported-by: Giuseppe Di Natale OpenZFS-issue: https://www.illumos.org/issues/8603 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/2daf06546b Closes #6927 --- diff --git a/include/sys/zil_impl.h b/include/sys/zil_impl.h index 3f69b3265..7e27215ca 100644 --- a/include/sys/zil_impl.h +++ b/include/sys/zil_impl.h @@ -56,9 +56,9 @@ typedef enum { * Log write block (lwb) * * Prior to an lwb being issued to disk via zil_lwb_write_issue(), it - * will be protected by the zilog's "zl_writer_lock". Basically, prior + * will be protected by the zilog's "zl_issuer_lock". Basically, prior * to it being issued, it will only be accessed by the thread that's - * holding the "zl_writer_lock". After the lwb is issued, the zilog's + * holding the "zl_issuer_lock". After the lwb is issued, the zilog's * "zl_lock" is used to protect the lwb against concurrent access. */ typedef struct lwb { @@ -92,10 +92,10 @@ typedef struct lwb { * * The "zcw_lock" field is used to protect the commit waiter against * concurrent access. This lock is often acquired while already holding - * the zilog's "zl_writer_lock" or "zl_lock"; see the functions + * the zilog's "zl_issuer_lock" or "zl_lock"; see the functions * zil_process_commit_list() and zil_lwb_flush_vdevs_done() as examples * of this. Thus, one must be careful not to acquire the - * "zl_writer_lock" or "zl_lock" when already holding the "zcw_lock"; + * "zl_issuer_lock" or "zl_lock" when already holding the "zcw_lock"; * e.g. see the zil_commit_waiter_timeout() function. */ typedef struct zil_commit_waiter { @@ -162,7 +162,7 @@ struct zilog { uint8_t zl_keep_first; /* keep first log block in destroy */ uint8_t zl_replay; /* replaying records while set */ uint8_t zl_stop_sync; /* for debugging */ - kmutex_t zl_writer_lock; /* single writer, per ZIL, at a time */ + kmutex_t zl_issuer_lock; /* single writer, per ZIL, at a time */ uint8_t zl_logbias; /* latency or throughput */ uint8_t zl_sync; /* synchronous or asynchronous */ int zl_parse_error; /* last zil_parse() error */ diff --git a/module/zfs/zil.c b/module/zfs/zil.c index 5300b3408..b5685d73b 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -1159,7 +1159,7 @@ zil_lwb_write_open(zilog_t *zilog, lwb_t *lwb) zbookmark_phys_t zb; zio_priority_t prio; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb, !=, NULL); EQUIV(lwb->lwb_root_zio == NULL, lwb->lwb_state == LWB_STATE_CLOSED); EQUIV(lwb->lwb_root_zio != NULL, lwb->lwb_state == LWB_STATE_OPENED); @@ -1261,7 +1261,7 @@ zil_lwb_write_issue(zilog_t *zilog, lwb_t *lwb) int i, error; boolean_t slog; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb->lwb_root_zio, !=, NULL); ASSERT3P(lwb->lwb_write_zio, !=, NULL); ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); @@ -1400,7 +1400,7 @@ zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) char *lr_buf; uint64_t dlen, dnow, lwb_sp, reclen, txg; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb, !=, NULL); ASSERT3P(lwb->lwb_buf, !=, NULL); @@ -1837,7 +1837,7 @@ zil_get_commit_list(zilog_t *zilog) uint64_t otxg, txg; list_t *commit_list = &zilog->zl_itx_commit_list; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ otxg = ZILTEST_TXG; @@ -1944,7 +1944,7 @@ zil_prune_commit_list(zilog_t *zilog) { itx_t *itx; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) { lr_t *lrc = &itx->itx_lr; @@ -1994,12 +1994,12 @@ zil_commit_writer_stall(zilog_t *zilog) * crash (because the previous lwb on-disk would not point to * it). * - * We must hold the zilog's zl_writer_lock while we do this, to + * We must hold the zilog's zl_issuer_lock while we do this, to * ensure no new threads enter zil_process_commit_list() until * all lwb's in the zl_lwb_list have been synced and freed * (which is achieved via the txg_wait_synced() call). */ - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); txg_wait_synced(zilog->zl_dmu_pool, 0); ASSERT3P(list_tail(&zilog->zl_lwb_list), ==, NULL); } @@ -2019,7 +2019,7 @@ zil_process_commit_list(zilog_t *zilog) lwb_t *lwb; itx_t *itx; - ASSERT(MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); /* * Return if there's nothing to commit before we dirty the fs by @@ -2207,17 +2207,17 @@ zil_commit_writer(zilog_t *zilog, zil_commit_waiter_t *zcw) ASSERT(spa_writeable(zilog->zl_spa)); ASSERT0(zilog->zl_suspend); - mutex_enter(&zilog->zl_writer_lock); + mutex_enter(&zilog->zl_issuer_lock); if (zcw->zcw_lwb != NULL || zcw->zcw_done) { /* * It's possible that, while we were waiting to acquire - * the "zl_writer_lock", another thread committed this + * the "zl_issuer_lock", another thread committed this * waiter to an lwb. If that occurs, we bail out early, * without processing any of the zilog's queue of itxs. * * On certain workloads and system configurations, the - * "zl_writer_lock" can become highly contended. In an + * "zl_issuer_lock" can become highly contended. In an * attempt to reduce this contention, we immediately drop * the lock if the waiter has already been processed. * @@ -2236,13 +2236,13 @@ zil_commit_writer(zilog_t *zilog, zil_commit_waiter_t *zcw) zil_process_commit_list(zilog); out: - mutex_exit(&zilog->zl_writer_lock); + mutex_exit(&zilog->zl_issuer_lock); } static void zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) { - ASSERT(!MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT(MUTEX_HELD(&zcw->zcw_lock)); ASSERT3B(zcw->zcw_done, ==, B_FALSE); @@ -2254,7 +2254,7 @@ zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) * If the lwb has already been issued by another thread, we can * immediately return since there's no work to be done (the * point of this function is to issue the lwb). Additionally, we - * do this prior to acquiring the zl_writer_lock, to avoid + * do this prior to acquiring the zl_issuer_lock, to avoid * acquiring it when it's not necessary to do so. */ if (lwb->lwb_state == LWB_STATE_ISSUED || @@ -2263,13 +2263,13 @@ zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) /* * In order to call zil_lwb_write_issue() we must hold the - * zilog's "zl_writer_lock". We can't simply acquire that lock, + * zilog's "zl_issuer_lock". We can't simply acquire that lock, * since we're already holding the commit waiter's "zcw_lock", * and those two locks are aquired in the opposite order * elsewhere. */ mutex_exit(&zcw->zcw_lock); - mutex_enter(&zilog->zl_writer_lock); + mutex_enter(&zilog->zl_issuer_lock); mutex_enter(&zcw->zcw_lock); /* @@ -2287,7 +2287,7 @@ zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) /* * We've already checked this above, but since we hadn't - * acquired the zilog's zl_writer_lock, we have to perform this + * acquired the zilog's zl_issuer_lock, we have to perform this * check a second time while holding the lock. We can't call * zil_lwb_write_issue() if the lwb had already been issued. */ @@ -2350,7 +2350,7 @@ zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) } out: - mutex_exit(&zilog->zl_writer_lock); + mutex_exit(&zilog->zl_issuer_lock); ASSERT(MUTEX_HELD(&zcw->zcw_lock)); } @@ -2377,7 +2377,7 @@ static void zil_commit_waiter(zilog_t *zilog, zil_commit_waiter_t *zcw) { ASSERT(!MUTEX_HELD(&zilog->zl_lock)); - ASSERT(!MUTEX_HELD(&zilog->zl_writer_lock)); + ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT(spa_writeable(zilog->zl_spa)); ASSERT0(zilog->zl_suspend); @@ -2626,7 +2626,7 @@ zil_commit_itx_assign(zilog_t *zilog, zil_commit_waiter_t *zcw) * on two fundamental concepts: * * 1. The creation and issuance of lwb zio's is protected by - * the zilog's "zl_writer_lock", which ensures only a single + * the zilog's "zl_issuer_lock", which ensures only a single * thread is creating and/or issuing lwb's at a time * 2. The "previous" lwb is a child of the "current" lwb * (leveraging the zio parent-child depenency graph) @@ -2906,7 +2906,7 @@ zil_alloc(objset_t *os, zil_header_t *zh_phys) zilog->zl_last_lwb_latency = 0; mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); - mutex_init(&zilog->zl_writer_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&zilog->zl_issuer_lock, NULL, MUTEX_DEFAULT, NULL); for (int i = 0; i < TXG_SIZE; i++) { mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, @@ -2953,7 +2953,7 @@ zil_free(zilog_t *zilog) mutex_destroy(&zilog->zl_itxg[i].itxg_lock); } - mutex_destroy(&zilog->zl_writer_lock); + mutex_destroy(&zilog->zl_issuer_lock); mutex_destroy(&zilog->zl_lock); cv_destroy(&zilog->zl_cv_suspend);