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-rw-r--r--cmd/ztest/ztest.c11
-rw-r--r--include/sys/dmu.h2
-rw-r--r--include/sys/trace_zil.h234
-rw-r--r--include/sys/zil.h8
-rw-r--r--include/sys/zil_impl.h73
-rw-r--r--include/sys/zio.h1
-rw-r--r--lib/libspl/include/assert.h3
-rw-r--r--lib/libspl/include/sys/time.h14
-rw-r--r--module/zfs/dmu.c7
-rw-r--r--module/zfs/txg.c12
-rw-r--r--module/zfs/zfs_vnops.c12
-rw-r--r--module/zfs/zil.c1542
-rw-r--r--module/zfs/zio.c33
-rw-r--r--module/zfs/zvol.c11
-rwxr-xr-xscripts/zloop.sh2
15 files changed, 1587 insertions, 378 deletions
diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c
index e1b1ae3ff..46dd903f8 100644
--- a/cmd/ztest/ztest.c
+++ b/cmd/ztest/ztest.c
@@ -2144,14 +2144,15 @@ ztest_get_done(zgd_t *zgd, int error)
ztest_object_unlock(zd, object);
if (error == 0 && zgd->zgd_bp)
- zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
+ zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
umem_free(zgd, sizeof (*zgd));
umem_free(zzp, sizeof (*zzp));
}
static int
-ztest_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
+ztest_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb,
+ zio_t *zio)
{
ztest_ds_t *zd = arg;
objset_t *os = zd->zd_os;
@@ -2166,6 +2167,10 @@ ztest_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
int error;
ztest_zgd_private_t *zgd_private;
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3P(zio, !=, NULL);
+ ASSERT3U(size, !=, 0);
+
ztest_object_lock(zd, object, RL_READER);
error = dmu_bonus_hold(os, object, FTAG, &db);
if (error) {
@@ -2186,7 +2191,7 @@ ztest_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
db = NULL;
zgd = umem_zalloc(sizeof (*zgd), UMEM_NOFAIL);
- zgd->zgd_zilog = zd->zd_zilog;
+ zgd->zgd_lwb = lwb;
zgd_private = umem_zalloc(sizeof (ztest_zgd_private_t), UMEM_NOFAIL);
zgd_private->z_zd = zd;
zgd_private->z_object = object;
diff --git a/include/sys/dmu.h b/include/sys/dmu.h
index 8a9291900..f252a9cb6 100644
--- a/include/sys/dmu.h
+++ b/include/sys/dmu.h
@@ -982,7 +982,7 @@ uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
* {zfs,zvol,ztest}_get_done() args
*/
typedef struct zgd {
- struct zilog *zgd_zilog;
+ struct lwb *zgd_lwb;
struct blkptr *zgd_bp;
dmu_buf_t *zgd_db;
struct rl *zgd_rl;
diff --git a/include/sys/trace_zil.h b/include/sys/trace_zil.h
index eaa391270..ff16c8686 100644
--- a/include/sys/trace_zil.h
+++ b/include/sys/trace_zil.h
@@ -33,89 +33,181 @@
#include <linux/tracepoint.h>
#include <sys/types.h>
+#define ZILOG_TP_STRUCT_ENTRY \
+ __field(uint64_t, zl_lr_seq) \
+ __field(uint64_t, zl_commit_lr_seq) \
+ __field(uint64_t, zl_destroy_txg) \
+ __field(uint64_t, zl_replaying_seq) \
+ __field(uint32_t, zl_suspend) \
+ __field(uint8_t, zl_suspending) \
+ __field(uint8_t, zl_keep_first) \
+ __field(uint8_t, zl_replay) \
+ __field(uint8_t, zl_stop_sync) \
+ __field(uint8_t, zl_logbias) \
+ __field(uint8_t, zl_sync) \
+ __field(int, zl_parse_error) \
+ __field(uint64_t, zl_parse_blk_seq) \
+ __field(uint64_t, zl_parse_lr_seq) \
+ __field(uint64_t, zl_parse_blk_count) \
+ __field(uint64_t, zl_parse_lr_count) \
+ __field(uint64_t, zl_cur_used) \
+ __field(clock_t, zl_replay_time) \
+ __field(uint64_t, zl_replay_blks)
+
+#define ZILOG_TP_FAST_ASSIGN \
+ __entry->zl_lr_seq = zilog->zl_lr_seq; \
+ __entry->zl_commit_lr_seq = zilog->zl_commit_lr_seq; \
+ __entry->zl_destroy_txg = zilog->zl_destroy_txg; \
+ __entry->zl_replaying_seq = zilog->zl_replaying_seq; \
+ __entry->zl_suspend = zilog->zl_suspend; \
+ __entry->zl_suspending = zilog->zl_suspending; \
+ __entry->zl_keep_first = zilog->zl_keep_first; \
+ __entry->zl_replay = zilog->zl_replay; \
+ __entry->zl_stop_sync = zilog->zl_stop_sync; \
+ __entry->zl_logbias = zilog->zl_logbias; \
+ __entry->zl_sync = zilog->zl_sync; \
+ __entry->zl_parse_error = zilog->zl_parse_error; \
+ __entry->zl_parse_blk_seq = zilog->zl_parse_blk_seq; \
+ __entry->zl_parse_lr_seq = zilog->zl_parse_lr_seq; \
+ __entry->zl_parse_blk_count = zilog->zl_parse_blk_count;\
+ __entry->zl_parse_lr_count = zilog->zl_parse_lr_count; \
+ __entry->zl_cur_used = zilog->zl_cur_used; \
+ __entry->zl_replay_time = zilog->zl_replay_time; \
+ __entry->zl_replay_blks = zilog->zl_replay_blks;
+
+#define ZILOG_TP_PRINTK_FMT \
+ "zl { lr_seq %llu commit_lr_seq %llu destroy_txg %llu " \
+ "replaying_seq %llu suspend %u suspending %u keep_first %u " \
+ "replay %u stop_sync %u logbias %u sync %u " \
+ "parse_error %u parse_blk_seq %llu parse_lr_seq %llu " \
+ "parse_blk_count %llu parse_lr_count %llu " \
+ "cur_used %llu replay_time %lu replay_blks %llu }"
+
+#define ZILOG_TP_PRINTK_ARGS \
+ __entry->zl_lr_seq, __entry->zl_commit_lr_seq, \
+ __entry->zl_destroy_txg, __entry->zl_replaying_seq, \
+ __entry->zl_suspend, __entry->zl_suspending, \
+ __entry->zl_keep_first, __entry->zl_replay, \
+ __entry->zl_stop_sync, __entry->zl_logbias, __entry->zl_sync, \
+ __entry->zl_parse_error, __entry->zl_parse_blk_seq, \
+ __entry->zl_parse_lr_seq, __entry->zl_parse_blk_count, \
+ __entry->zl_parse_lr_count, __entry->zl_cur_used, \
+ __entry->zl_replay_time, __entry->zl_replay_blks
+
+#define ITX_TP_STRUCT_ENTRY \
+ __field(itx_wr_state_t, itx_wr_state) \
+ __field(uint8_t, itx_sync) \
+ __field(zil_callback_t, itx_callback) \
+ __field(void *, itx_callback_data) \
+ __field(uint64_t, itx_oid) \
+ \
+ __field(uint64_t, lrc_txtype) \
+ __field(uint64_t, lrc_reclen) \
+ __field(uint64_t, lrc_txg) \
+ __field(uint64_t, lrc_seq)
+
+#define ITX_TP_FAST_ASSIGN \
+ __entry->itx_wr_state = itx->itx_wr_state; \
+ __entry->itx_sync = itx->itx_sync; \
+ __entry->itx_callback = itx->itx_callback; \
+ __entry->itx_callback_data = itx->itx_callback_data; \
+ __entry->itx_oid = itx->itx_oid; \
+ \
+ __entry->lrc_txtype = itx->itx_lr.lrc_txtype; \
+ __entry->lrc_reclen = itx->itx_lr.lrc_reclen; \
+ __entry->lrc_txg = itx->itx_lr.lrc_txg; \
+ __entry->lrc_seq = itx->itx_lr.lrc_seq;
+
+#define ITX_TP_PRINTK_FMT \
+ "itx { wr_state %u sync %u callback %p callback_data %p oid %llu" \
+ " { txtype %llu reclen %llu txg %llu seq %llu } }"
+
+#define ITX_TP_PRINTK_ARGS \
+ __entry->itx_wr_state, __entry->itx_sync, __entry->itx_callback,\
+ __entry->itx_callback_data, __entry->itx_oid, \
+ __entry->lrc_txtype, __entry->lrc_reclen, __entry->lrc_txg, \
+ __entry->lrc_seq
+
+#define ZCW_TP_STRUCT_ENTRY \
+ __field(lwb_t *, zcw_lwb) \
+ __field(boolean_t, zcw_done) \
+ __field(int, zcw_zio_error) \
+
+#define ZCW_TP_FAST_ASSIGN \
+ __entry->zcw_lwb = zcw->zcw_lwb; \
+ __entry->zcw_done = zcw->zcw_done; \
+ __entry->zcw_zio_error = zcw->zcw_zio_error;
+
+#define ZCW_TP_PRINTK_FMT \
+ "zcw { lwb %p done %u error %u }"
+
+#define ZCW_TP_PRINTK_ARGS \
+ __entry->zcw_lwb, __entry->zcw_done, __entry->zcw_zio_error
+
/*
- * Generic support for one argument tracepoints of the form:
+ * Generic support for two argument tracepoints of the form:
*
- * DTRACE_PROBE1(...,
- * zilog_t *, ...);
+ * DTRACE_PROBE2(...,
+ * zilog_t *, ...,
+ * itx_t *, ...);
*/
/* BEGIN CSTYLED */
-DECLARE_EVENT_CLASS(zfs_zil_class,
- TP_PROTO(zilog_t *zilog),
- TP_ARGS(zilog),
+DECLARE_EVENT_CLASS(zfs_zil_process_itx_class,
+ TP_PROTO(zilog_t *zilog, itx_t *itx),
+ TP_ARGS(zilog, itx),
TP_STRUCT__entry(
- __field(uint64_t, zl_lr_seq)
- __field(uint64_t, zl_commit_lr_seq)
- __field(uint64_t, zl_destroy_txg)
- __field(uint64_t, zl_replaying_seq)
- __field(uint32_t, zl_suspend)
- __field(uint8_t, zl_suspending)
- __field(uint8_t, zl_keep_first)
- __field(uint8_t, zl_replay)
- __field(uint8_t, zl_stop_sync)
- __field(uint8_t, zl_writer)
- __field(uint8_t, zl_logbias)
- __field(uint8_t, zl_sync)
- __field(int, zl_parse_error)
- __field(uint64_t, zl_parse_blk_seq)
- __field(uint64_t, zl_parse_lr_seq)
- __field(uint64_t, zl_parse_blk_count)
- __field(uint64_t, zl_parse_lr_count)
- __field(uint64_t, zl_next_batch)
- __field(uint64_t, zl_com_batch)
- __field(uint64_t, zl_cur_used)
- __field(clock_t, zl_replay_time)
- __field(uint64_t, zl_replay_blks)
+ ZILOG_TP_STRUCT_ENTRY
+ ITX_TP_STRUCT_ENTRY
),
TP_fast_assign(
- __entry->zl_lr_seq = zilog->zl_lr_seq;
- __entry->zl_commit_lr_seq = zilog->zl_commit_lr_seq;
- __entry->zl_destroy_txg = zilog->zl_destroy_txg;
- __entry->zl_replaying_seq = zilog->zl_replaying_seq;
- __entry->zl_suspend = zilog->zl_suspend;
- __entry->zl_suspending = zilog->zl_suspending;
- __entry->zl_keep_first = zilog->zl_keep_first;
- __entry->zl_replay = zilog->zl_replay;
- __entry->zl_stop_sync = zilog->zl_stop_sync;
- __entry->zl_writer = zilog->zl_writer;
- __entry->zl_logbias = zilog->zl_logbias;
- __entry->zl_sync = zilog->zl_sync;
- __entry->zl_parse_error = zilog->zl_parse_error;
- __entry->zl_parse_blk_seq = zilog->zl_parse_blk_seq;
- __entry->zl_parse_lr_seq = zilog->zl_parse_lr_seq;
- __entry->zl_parse_blk_count = zilog->zl_parse_blk_count;
- __entry->zl_parse_lr_count = zilog->zl_parse_lr_count;
- __entry->zl_next_batch = zilog->zl_next_batch;
- __entry->zl_com_batch = zilog->zl_com_batch;
- __entry->zl_cur_used = zilog->zl_cur_used;
- __entry->zl_replay_time = zilog->zl_replay_time;
- __entry->zl_replay_blks = zilog->zl_replay_blks;
+ ZILOG_TP_FAST_ASSIGN
+ ITX_TP_FAST_ASSIGN
),
- TP_printk("zl { lr_seq %llu commit_lr_seq %llu destroy_txg %llu "
- "replaying_seq %llu suspend %u suspending %u keep_first %u "
- "replay %u stop_sync %u writer %u logbias %u sync %u "
- "parse_error %u parse_blk_seq %llu parse_lr_seq %llu "
- "parse_blk_count %llu parse_lr_count %llu next_batch %llu "
- "com_batch %llu cur_used %llu replay_time %lu replay_blks %llu }",
- __entry->zl_lr_seq, __entry->zl_commit_lr_seq,
- __entry->zl_destroy_txg, __entry->zl_replaying_seq,
- __entry->zl_suspend, __entry->zl_suspending, __entry->zl_keep_first,
- __entry->zl_replay, __entry->zl_stop_sync, __entry->zl_writer,
- __entry->zl_logbias, __entry->zl_sync, __entry->zl_parse_error,
- __entry->zl_parse_blk_seq, __entry->zl_parse_lr_seq,
- __entry->zl_parse_blk_count, __entry->zl_parse_lr_count,
- __entry->zl_next_batch, __entry->zl_com_batch, __entry->zl_cur_used,
- __entry->zl_replay_time, __entry->zl_replay_blks)
+ TP_printk(
+ ZILOG_TP_PRINTK_FMT " " ITX_TP_PRINTK_FMT,
+ ZILOG_TP_PRINTK_ARGS, ITX_TP_PRINTK_ARGS)
);
/* END CSTYLED */
/* BEGIN CSTYLED */
-#define DEFINE_ZIL_EVENT(name) \
-DEFINE_EVENT(zfs_zil_class, name, \
- TP_PROTO(zilog_t *zilog), \
- TP_ARGS(zilog))
-DEFINE_ZIL_EVENT(zfs_zil__cw1);
-DEFINE_ZIL_EVENT(zfs_zil__cw2);
+#define DEFINE_ZIL_PROCESS_ITX_EVENT(name) \
+DEFINE_EVENT(zfs_zil_process_itx_class, name, \
+ TP_PROTO(zilog_t *zilog, itx_t *itx), \
+ TP_ARGS(zilog, itx))
+DEFINE_ZIL_PROCESS_ITX_EVENT(zfs_zil__process__commit__itx);
+DEFINE_ZIL_PROCESS_ITX_EVENT(zfs_zil__process__normal__itx);
+/* END CSTYLED */
+
+/*
+ * Generic support for two argument tracepoints of the form:
+ *
+ * DTRACE_PROBE2(...,
+ * zilog_t *, ...,
+ * zil_commit_waiter_t *, ...);
+ */
+/* BEGIN CSTYLED */
+DECLARE_EVENT_CLASS(zfs_zil_commit_io_error_class,
+ TP_PROTO(zilog_t *zilog, zil_commit_waiter_t *zcw),
+ TP_ARGS(zilog, zcw),
+ TP_STRUCT__entry(
+ ZILOG_TP_STRUCT_ENTRY
+ ZCW_TP_STRUCT_ENTRY
+ ),
+ TP_fast_assign(
+ ZILOG_TP_FAST_ASSIGN
+ ZCW_TP_FAST_ASSIGN
+ ),
+ TP_printk(
+ ZILOG_TP_PRINTK_FMT " " ZCW_TP_PRINTK_FMT,
+ ZILOG_TP_PRINTK_ARGS, ZCW_TP_PRINTK_ARGS)
+);
+
+/* BEGIN CSTYLED */
+#define DEFINE_ZIL_COMMIT_IO_ERROR_EVENT(name) \
+DEFINE_EVENT(zfs_zil_commit_io_error_class, name, \
+ TP_PROTO(zilog_t *zilog, zil_commit_waiter_t *zcw), \
+ TP_ARGS(zilog, zcw))
+DEFINE_ZIL_COMMIT_IO_ERROR_EVENT(zfs_zil__commit__io__error);
/* END CSTYLED */
#endif /* _TRACE_ZIL_H */
diff --git a/include/sys/zil.h b/include/sys/zil.h
index 442fee4a1..5513c7ce8 100644
--- a/include/sys/zil.h
+++ b/include/sys/zil.h
@@ -40,6 +40,7 @@ extern "C" {
struct dsl_pool;
struct dsl_dataset;
+struct lwb;
/*
* Intent log format:
@@ -140,6 +141,7 @@ typedef enum zil_create {
/*
* Intent log transaction types and record structures
*/
+#define TX_COMMIT 0 /* Commit marker (no on-disk state) */
#define TX_CREATE 1 /* Create file */
#define TX_MKDIR 2 /* Make directory */
#define TX_MKXATTR 3 /* Make XATTR directory */
@@ -465,7 +467,8 @@ typedef int zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
typedef int zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
uint64_t txg);
typedef int zil_replay_func_t(void *arg1, void *arg2, boolean_t byteswap);
-typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);
+typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf,
+ struct lwb *lwb, zio_t *zio);
extern int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg,
@@ -503,7 +506,8 @@ extern void zil_clean(zilog_t *zilog, uint64_t synced_txg);
extern int zil_suspend(const char *osname, void **cookiep);
extern void zil_resume(void *cookie);
-extern void zil_add_block(zilog_t *zilog, const blkptr_t *bp);
+extern void zil_lwb_add_block(struct lwb *lwb, const blkptr_t *bp);
+extern void zil_lwb_add_txg(struct lwb *lwb, uint64_t txg);
extern int zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp);
extern void zil_set_sync(zilog_t *zilog, uint64_t syncval);
diff --git a/include/sys/zil_impl.h b/include/sys/zil_impl.h
index dd5304b79..3f69b3265 100644
--- a/include/sys/zil_impl.h
+++ b/include/sys/zil_impl.h
@@ -20,7 +20,7 @@
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
*/
/* Portions Copyright 2010 Robert Milkowski */
@@ -36,7 +36,30 @@ extern "C" {
#endif
/*
- * Log write buffer.
+ * Possbile states for a given lwb structure. An lwb will start out in
+ * the "closed" state, and then transition to the "opened" state via a
+ * call to zil_lwb_write_open(). After the lwb is "open", it can
+ * transition into the "issued" state via zil_lwb_write_issue(). After
+ * the lwb's zio completes, and the vdev's are flushed, the lwb will
+ * transition into the "done" state via zil_lwb_write_done(), and the
+ * structure eventually freed.
+ */
+typedef enum {
+ LWB_STATE_CLOSED,
+ LWB_STATE_OPENED,
+ LWB_STATE_ISSUED,
+ LWB_STATE_DONE,
+ LWB_NUM_STATES
+} lwb_state_t;
+
+/*
+ * 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
+ * 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
+ * "zl_lock" is used to protect the lwb against concurrent access.
*/
typedef struct lwb {
zilog_t *lwb_zilog; /* back pointer to log struct */
@@ -45,14 +68,46 @@ typedef struct lwb {
boolean_t lwb_slog; /* lwb_blk is on SLOG device */
int lwb_nused; /* # used bytes in buffer */
int lwb_sz; /* size of block and buffer */
+ lwb_state_t lwb_state; /* the state of this lwb */
char *lwb_buf; /* log write buffer */
- zio_t *lwb_zio; /* zio for this buffer */
+ zio_t *lwb_write_zio; /* zio for the lwb buffer */
+ zio_t *lwb_root_zio; /* root zio for lwb write and flushes */
dmu_tx_t *lwb_tx; /* tx for log block allocation */
uint64_t lwb_max_txg; /* highest txg in this lwb */
list_node_t lwb_node; /* zilog->zl_lwb_list linkage */
+ list_t lwb_itxs; /* list of itx's */
+ list_t lwb_waiters; /* list of zil_commit_waiter's */
+ avl_tree_t lwb_vdev_tree; /* vdevs to flush after lwb write */
+ kmutex_t lwb_vdev_lock; /* protects lwb_vdev_tree */
+ hrtime_t lwb_issued_timestamp; /* when was the lwb issued? */
} lwb_t;
/*
+ * ZIL commit waiter.
+ *
+ * This structure is allocated each time zil_commit() is called, and is
+ * used by zil_commit() to communicate with other parts of the ZIL, such
+ * that zil_commit() can know when it safe for it return. For more
+ * details, see the comment above zil_commit().
+ *
+ * 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
+ * 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";
+ * e.g. see the zil_commit_waiter_timeout() function.
+ */
+typedef struct zil_commit_waiter {
+ kcondvar_t zcw_cv; /* signalled when "done" */
+ kmutex_t zcw_lock; /* protects fields of this struct */
+ list_node_t zcw_node; /* linkage in lwb_t:lwb_waiter list */
+ lwb_t *zcw_lwb; /* back pointer to lwb when linked */
+ boolean_t zcw_done; /* B_TRUE when "done", else B_FALSE */
+ int zcw_zio_error; /* contains the zio io_error value */
+} zil_commit_waiter_t;
+
+/*
* Intent log transaction lists
*/
typedef struct itxs {
@@ -94,20 +149,20 @@ struct zilog {
const zil_header_t *zl_header; /* log header buffer */
objset_t *zl_os; /* object set we're logging */
zil_get_data_t *zl_get_data; /* callback to get object content */
- zio_t *zl_root_zio; /* log writer root zio */
+ lwb_t *zl_last_lwb_opened; /* most recent lwb opened */
+ hrtime_t zl_last_lwb_latency; /* zio latency of last lwb done */
uint64_t zl_lr_seq; /* on-disk log record sequence number */
uint64_t zl_commit_lr_seq; /* last committed on-disk lr seq */
uint64_t zl_destroy_txg; /* txg of last zil_destroy() */
uint64_t zl_replayed_seq[TXG_SIZE]; /* last replayed rec seq */
uint64_t zl_replaying_seq; /* current replay seq number */
uint32_t zl_suspend; /* log suspend count */
- kcondvar_t zl_cv_writer; /* log writer thread completion */
kcondvar_t zl_cv_suspend; /* log suspend completion */
uint8_t zl_suspending; /* log is currently suspending */
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 */
- uint8_t zl_writer; /* boolean: write setup in progress */
+ kmutex_t zl_writer_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 */
@@ -115,15 +170,10 @@ struct zilog {
uint64_t zl_parse_lr_seq; /* highest lr seq on last parse */
uint64_t zl_parse_blk_count; /* number of blocks parsed */
uint64_t zl_parse_lr_count; /* number of log records parsed */
- uint64_t zl_next_batch; /* next batch number */
- uint64_t zl_com_batch; /* committed batch number */
- kcondvar_t zl_cv_batch[2]; /* batch condition variables */
itxg_t zl_itxg[TXG_SIZE]; /* intent log txg chains */
list_t zl_itx_commit_list; /* itx list to be committed */
uint64_t zl_cur_used; /* current commit log size used */
list_t zl_lwb_list; /* in-flight log write list */
- kmutex_t zl_vdev_lock; /* protects zl_vdev_tree */
- avl_tree_t zl_vdev_tree; /* vdevs to flush in zil_commit() */
avl_tree_t zl_bp_tree; /* track bps during log parse */
clock_t zl_replay_time; /* lbolt of when replay started */
uint64_t zl_replay_blks; /* number of log blocks replayed */
@@ -131,6 +181,7 @@ struct zilog {
uint_t zl_prev_blks[ZIL_PREV_BLKS]; /* size - sector rounded */
uint_t zl_prev_rotor; /* rotor for zl_prev[] */
txg_node_t zl_dirty_link; /* protected by dp_dirty_zilogs list */
+ uint64_t zl_dirty_max_txg; /* highest txg used to dirty zilog */
};
typedef struct zil_bp_node {
diff --git a/include/sys/zio.h b/include/sys/zio.h
index 30c4ee3ce..1f9f48268 100644
--- a/include/sys/zio.h
+++ b/include/sys/zio.h
@@ -596,6 +596,7 @@ extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
extern enum zio_compress zio_compress_select(spa_t *spa,
enum zio_compress child, enum zio_compress parent);
+extern void zio_cancel(zio_t *zio);
extern void zio_suspend(spa_t *spa, zio_t *zio);
extern int zio_resume(spa_t *spa);
extern void zio_resume_wait(spa_t *spa);
diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index 026d6fef9..c080bc8aa 100644
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -76,6 +76,7 @@ do { \
(u_longlong_t)__left, #OP, (u_longlong_t)__right); \
} while (0)
+#define VERIFY3B(x, y, z) VERIFY3_IMPL(x, y, z, boolean_t)
#define VERIFY3S(x, y, z) VERIFY3_IMPL(x, y, z, int64_t)
#define VERIFY3U(x, y, z) VERIFY3_IMPL(x, y, z, uint64_t)
#define VERIFY3P(x, y, z) VERIFY3_IMPL(x, y, z, uintptr_t)
@@ -94,6 +95,7 @@ do { \
__compile_time_assertion__ ## y[(x) ? 1 : -1]
#ifdef NDEBUG
+#define ASSERT3B(x, y, z) ((void)0)
#define ASSERT3S(x, y, z) ((void)0)
#define ASSERT3U(x, y, z) ((void)0)
#define ASSERT3P(x, y, z) ((void)0)
@@ -104,6 +106,7 @@ do { \
#define IMPLY(A, B) ((void)0)
#define EQUIV(A, B) ((void)0)
#else
+#define ASSERT3B(x, y, z) VERIFY3B(x, y, z)
#define ASSERT3S(x, y, z) VERIFY3S(x, y, z)
#define ASSERT3U(x, y, z) VERIFY3U(x, y, z)
#define ASSERT3P(x, y, z) VERIFY3P(x, y, z)
diff --git a/lib/libspl/include/sys/time.h b/lib/libspl/include/sys/time.h
index f05fcaa1c..b3dd74dd5 100644
--- a/lib/libspl/include/sys/time.h
+++ b/lib/libspl/include/sys/time.h
@@ -51,14 +51,22 @@
#endif
#ifndef MSEC2NSEC
-#define MSEC2NSEC(m) ((hrtime_t)(m) * (NANOSEC / MILLISEC))
+#define MSEC2NSEC(m) ((hrtime_t)(m) * (NANOSEC / MILLISEC))
#endif
#ifndef NSEC2MSEC
-#define NSEC2MSEC(n) ((n) / (NANOSEC / MILLISEC))
+#define NSEC2MSEC(n) ((n) / (NANOSEC / MILLISEC))
#endif
-#ifndef NSEC2SEC
+#ifndef USEC2NSEC
+#define USEC2NSEC(m) ((hrtime_t)(m) * (NANOSEC / MICROSEC))
+#endif
+
+#ifndef NSEC2USEC
+#define NSEC2USEC(n) ((n) / (NANOSEC / MICROSEC))
+#endif
+
+#ifndef NSEC2SEC
#define NSEC2SEC(n) ((n) / (NANOSEC / SEC))
#endif
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 108dfe157..56740ae37 100644
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -1783,6 +1783,13 @@ dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
return (SET_ERROR(EIO));
}
+ /*
+ * In order to prevent the zgd's lwb from being free'd prior to
+ * dmu_sync_late_arrival_done() being called, we have to ensure
+ * the lwb's "max txg" takes this tx's txg into account.
+ */
+ zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
+
dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
dsa->dsa_dr = NULL;
dsa->dsa_done = done;
diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 078839a32..bf8544507 100644
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -160,7 +160,7 @@ txg_fini(dsl_pool_t *dp)
tx_state_t *tx = &dp->dp_tx;
int c;
- ASSERT(tx->tx_threads == 0);
+ ASSERT0(tx->tx_threads);
mutex_destroy(&tx->tx_sync_lock);
@@ -201,7 +201,7 @@ txg_sync_start(dsl_pool_t *dp)
dprintf("pool %p\n", dp);
- ASSERT(tx->tx_threads == 0);
+ ASSERT0(tx->tx_threads);
tx->tx_threads = 2;
@@ -263,7 +263,7 @@ txg_sync_stop(dsl_pool_t *dp)
/*
* Finish off any work in progress.
*/
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
/*
* We need to ensure that we've vacated the deferred space_maps.
@@ -275,7 +275,7 @@ txg_sync_stop(dsl_pool_t *dp)
*/
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
tx->tx_exiting = 1;
@@ -648,7 +648,7 @@ txg_wait_synced(dsl_pool_t *dp, uint64_t txg)
ASSERT(!dsl_pool_config_held(dp));
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
if (txg == 0)
txg = tx->tx_open_txg + TXG_DEFER_SIZE;
if (tx->tx_sync_txg_waiting < txg)
@@ -673,7 +673,7 @@ txg_wait_open(dsl_pool_t *dp, uint64_t txg)
ASSERT(!dsl_pool_config_held(dp));
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
if (txg == 0)
txg = tx->tx_open_txg + 1;
if (tx->tx_quiesce_txg_waiting < txg)
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index a60cd6198..977035fd9 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -78,6 +78,7 @@
#include <sys/cred.h>
#include <sys/attr.h>
#include <sys/zpl.h>
+#include <sys/zil.h>
/*
* Programming rules.
@@ -983,7 +984,7 @@ zfs_get_done(zgd_t *zgd, int error)
zfs_iput_async(ZTOI(zp));
if (error == 0 && zgd->zgd_bp)
- zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
+ zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
kmem_free(zgd, sizeof (zgd_t));
}
@@ -996,7 +997,7 @@ static int zil_fault_io = 0;
* Get data to generate a TX_WRITE intent log record.
*/
int
-zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
+zfs_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
{
zfsvfs_t *zfsvfs = arg;
objset_t *os = zfsvfs->z_os;
@@ -1008,8 +1009,9 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
zgd_t *zgd;
int error = 0;
- ASSERT(zio != NULL);
- ASSERT(size != 0);
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3P(zio, !=, NULL);
+ ASSERT3U(size, !=, 0);
/*
* Nothing to do if the file has been removed
@@ -1026,7 +1028,7 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
}
zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
- zgd->zgd_zilog = zfsvfs->z_log;
+ zgd->zgd_lwb = lwb;
zgd->zgd_private = zp;
/*
diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index 9f4312a5a..5300b3408 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -44,32 +44,53 @@
#include <sys/abd.h>
/*
- * The zfs intent log (ZIL) saves transaction records of system calls
- * that change the file system in memory with enough information
- * to be able to replay them. These are stored in memory until
- * either the DMU transaction group (txg) commits them to the stable pool
- * and they can be discarded, or they are flushed to the stable log
- * (also in the pool) due to a fsync, O_DSYNC or other synchronous
- * requirement. In the event of a panic or power fail then those log
- * records (transactions) are replayed.
+ * The ZFS Intent Log (ZIL) saves "transaction records" (itxs) of system
+ * calls that change the file system. Each itx has enough information to
+ * be able to replay them after a system crash, power loss, or
+ * equivalent failure mode. These are stored in memory until either:
*
- * There is one ZIL per file system. Its on-disk (pool) format consists
- * of 3 parts:
+ * 1. they are committed to the pool by the DMU transaction group
+ * (txg), at which point they can be discarded; or
+ * 2. they are committed to the on-disk ZIL for the dataset being
+ * modified (e.g. due to an fsync, O_DSYNC, or other synchronous
+ * requirement).
*
- * - ZIL header
- * - ZIL blocks
- * - ZIL records
+ * In the event of a crash or power loss, the itxs contained by each
+ * dataset's on-disk ZIL will be replayed when that dataset is first
+ * instantianted (e.g. if the dataset is a normal fileystem, when it is
+ * first mounted).
*
- * A log record holds a system call transaction. Log blocks can
- * hold many log records and the blocks are chained together.
- * Each ZIL block contains a block pointer (blkptr_t) to the next
- * ZIL block in the chain. The ZIL header points to the first
- * block in the chain. Note there is not a fixed place in the pool
- * to hold blocks. They are dynamically allocated and freed as
- * needed from the blocks available. Figure X shows the ZIL structure:
+ * As hinted at above, there is one ZIL per dataset (both the in-memory
+ * representation, and the on-disk representation). The on-disk format
+ * consists of 3 parts:
+ *
+ * - a single, per-dataset, ZIL header; which points to a chain of
+ * - zero or more ZIL blocks; each of which contains
+ * - zero or more ZIL records
+ *
+ * A ZIL record holds the information necessary to replay a single
+ * system call transaction. A ZIL block can hold many ZIL records, and
+ * the blocks are chained together, similarly to a singly linked list.
+ *
+ * Each ZIL block contains a block pointer (blkptr_t) to the next ZIL
+ * block in the chain, and the ZIL header points to the first block in
+ * the chain.
+ *
+ * Note, there is not a fixed place in the pool to hold these ZIL
+ * blocks; they are dynamically allocated and freed as needed from the
+ * blocks available on the pool, though they can be preferentially
+ * allocated from a dedicated "log" vdev.
*/
/*
+ * This controls the amount of time that a ZIL block (lwb) will remain
+ * "open" when it isn't "full", and it has a thread waiting for it to be
+ * committed to stable storage. Please refer to the zil_commit_waiter()
+ * function (and the comments within it) for more details.
+ */
+int zfs_commit_timeout_pct = 5;
+
+/*
* See zil.h for more information about these fields.
*/
zil_stats_t zil_stats = {
@@ -110,6 +131,7 @@ int zfs_nocacheflush = 0;
unsigned long zil_slog_bulk = 768 * 1024;
static kmem_cache_t *zil_lwb_cache;
+static kmem_cache_t *zil_zcw_cache;
static void zil_async_to_sync(zilog_t *zilog, uint64_t foid);
@@ -476,6 +498,15 @@ zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
return (0);
}
+static int
+zil_lwb_vdev_compare(const void *x1, const void *x2)
+{
+ const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
+ const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
+
+ return (AVL_CMP(v1, v2));
+}
+
static lwb_t *
zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg,
boolean_t fastwrite)
@@ -487,10 +518,13 @@ zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg,
lwb->lwb_blk = *bp;
lwb->lwb_fastwrite = fastwrite;
lwb->lwb_slog = slog;
+ lwb->lwb_state = LWB_STATE_CLOSED;
lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
lwb->lwb_max_txg = txg;
- lwb->lwb_zio = NULL;
+ lwb->lwb_write_zio = NULL;
+ lwb->lwb_root_zio = NULL;
lwb->lwb_tx = NULL;
+ lwb->lwb_issued_timestamp = 0;
if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
lwb->lwb_nused = sizeof (zil_chain_t);
lwb->lwb_sz = BP_GET_LSIZE(bp);
@@ -503,9 +537,64 @@ zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg,
list_insert_tail(&zilog->zl_lwb_list, lwb);
mutex_exit(&zilog->zl_lock);
+ ASSERT(!MUTEX_HELD(&lwb->lwb_vdev_lock));
+ ASSERT(avl_is_empty(&lwb->lwb_vdev_tree));
+ ASSERT(list_is_empty(&lwb->lwb_waiters));
+ ASSERT(list_is_empty(&lwb->lwb_itxs));
+
return (lwb);
}
+static void
+zil_free_lwb(zilog_t *zilog, lwb_t *lwb)
+{
+ ASSERT(MUTEX_HELD(&zilog->zl_lock));
+ ASSERT(!MUTEX_HELD(&lwb->lwb_vdev_lock));
+ ASSERT(list_is_empty(&lwb->lwb_waiters));
+
+ if (lwb->lwb_state == LWB_STATE_OPENED) {
+ avl_tree_t *t = &lwb->lwb_vdev_tree;
+ void *cookie = NULL;
+ zil_vdev_node_t *zv;
+ itx_t *itx;
+
+ while ((zv = avl_destroy_nodes(t, &cookie)) != NULL)
+ kmem_free(zv, sizeof (*zv));
+
+ while ((itx = list_head(&lwb->lwb_itxs)) != NULL) {
+ if (itx->itx_callback != NULL)
+ itx->itx_callback(itx->itx_callback_data);
+ list_remove(&lwb->lwb_itxs, itx);
+ zil_itx_destroy(itx);
+ }
+
+ ASSERT3P(lwb->lwb_root_zio, !=, NULL);
+ ASSERT3P(lwb->lwb_write_zio, !=, NULL);
+
+ zio_cancel(lwb->lwb_root_zio);
+ zio_cancel(lwb->lwb_write_zio);
+
+ lwb->lwb_root_zio = NULL;
+ lwb->lwb_write_zio = NULL;
+ } else {
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED);
+ }
+
+ ASSERT(avl_is_empty(&lwb->lwb_vdev_tree));
+ ASSERT(list_is_empty(&lwb->lwb_itxs));
+ ASSERT3P(lwb->lwb_write_zio, ==, NULL);
+ ASSERT3P(lwb->lwb_root_zio, ==, NULL);
+
+ /*
+ * Clear the zilog's field to indicate this lwb is no longer
+ * valid, and prevent use-after-free errors.
+ */
+ if (zilog->zl_last_lwb_opened == lwb)
+ zilog->zl_last_lwb_opened = NULL;
+
+ kmem_cache_free(zil_lwb_cache, lwb);
+}
+
/*
* Called when we create in-memory log transactions so that we know
* to cleanup the itxs at the end of spa_sync().
@@ -516,12 +605,16 @@ zilog_dirty(zilog_t *zilog, uint64_t txg)
dsl_pool_t *dp = zilog->zl_dmu_pool;
dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
+ ASSERT(spa_writeable(zilog->zl_spa));
+
if (ds->ds_is_snapshot)
panic("dirtying snapshot!");
if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) {
/* up the hold count until we can be written out */
dmu_buf_add_ref(ds->ds_dbuf, zilog);
+
+ zilog->zl_dirty_max_txg = MAX(txg, zilog->zl_dirty_max_txg);
}
}
@@ -590,7 +683,7 @@ zil_create(zilog_t *zilog)
*/
if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
tx = dmu_tx_create(zilog->zl_os);
- VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
+ VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
@@ -608,7 +701,7 @@ zil_create(zilog_t *zilog)
}
/*
- * Allocate a log write buffer (lwb) for the first log block.
+ * Allocate a log write block (lwb) for the first log block.
*/
if (error == 0)
lwb = zil_alloc_lwb(zilog, &blk, slog, txg, fastwrite);
@@ -629,13 +722,13 @@ zil_create(zilog_t *zilog)
}
/*
- * In one tx, free all log blocks and clear the log header.
- * If keep_first is set, then we're replaying a log with no content.
- * We want to keep the first block, however, so that the first
- * synchronous transaction doesn't require a txg_wait_synced()
- * in zil_create(). We don't need to txg_wait_synced() here either
- * when keep_first is set, because both zil_create() and zil_destroy()
- * will wait for any in-progress destroys to complete.
+ * In one tx, free all log blocks and clear the log header. If keep_first
+ * is set, then we're replaying a log with no content. We want to keep the
+ * first block, however, so that the first synchronous transaction doesn't
+ * require a txg_wait_synced() in zil_create(). We don't need to
+ * txg_wait_synced() here either when keep_first is set, because both
+ * zil_create() and zil_destroy() will wait for any in-progress destroys
+ * to complete.
*/
void
zil_destroy(zilog_t *zilog, boolean_t keep_first)
@@ -656,7 +749,7 @@ zil_destroy(zilog_t *zilog, boolean_t keep_first)
return;
tx = dmu_tx_create(zilog->zl_os);
- VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
+ VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
@@ -670,15 +763,15 @@ zil_destroy(zilog_t *zilog, boolean_t keep_first)
ASSERT(zh->zh_claim_txg == 0);
VERIFY(!keep_first);
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
- ASSERT(lwb->lwb_zio == NULL);
if (lwb->lwb_fastwrite)
metaslab_fastwrite_unmark(zilog->zl_spa,
&lwb->lwb_blk);
+
list_remove(&zilog->zl_lwb_list, lwb);
if (lwb->lwb_buf != NULL)
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
- zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
- kmem_cache_free(zil_lwb_cache, lwb);
+ zio_free(zilog->zl_spa, txg, &lwb->lwb_blk);
+ zil_free_lwb(zilog, lwb);
}
} else if (!keep_first) {
zil_destroy_sync(zilog, tx);
@@ -820,19 +913,64 @@ zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx)
return ((error == ECKSUM || error == ENOENT) ? 0 : error);
}
-static int
-zil_vdev_compare(const void *x1, const void *x2)
+/*
+ * When an itx is "skipped", this function is used to properly mark the
+ * waiter as "done, and signal any thread(s) waiting on it. An itx can
+ * be skipped (and not committed to an lwb) for a variety of reasons,
+ * one of them being that the itx was committed via spa_sync(), prior to
+ * it being committed to an lwb; this can happen if a thread calling
+ * zil_commit() is racing with spa_sync().
+ */
+static void
+zil_commit_waiter_skip(zil_commit_waiter_t *zcw)
{
- const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
- const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
+ mutex_enter(&zcw->zcw_lock);
+ ASSERT3B(zcw->zcw_done, ==, B_FALSE);
+ zcw->zcw_done = B_TRUE;
+ cv_broadcast(&zcw->zcw_cv);
+ mutex_exit(&zcw->zcw_lock);
+}
- return (AVL_CMP(v1, v2));
+/*
+ * This function is used when the given waiter is to be linked into an
+ * lwb's "lwb_waiter" list; i.e. when the itx is committed to the lwb.
+ * At this point, the waiter will no longer be referenced by the itx,
+ * and instead, will be referenced by the lwb.
+ */
+static void
+zil_commit_waiter_link_lwb(zil_commit_waiter_t *zcw, lwb_t *lwb)
+{
+ mutex_enter(&zcw->zcw_lock);
+ ASSERT(!list_link_active(&zcw->zcw_node));
+ ASSERT3P(zcw->zcw_lwb, ==, NULL);
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT(lwb->lwb_state == LWB_STATE_OPENED ||
+ lwb->lwb_state == LWB_STATE_ISSUED);
+
+ list_insert_tail(&lwb->lwb_waiters, zcw);
+ zcw->zcw_lwb = lwb;
+ mutex_exit(&zcw->zcw_lock);
+}
+
+/*
+ * This function is used when zio_alloc_zil() fails to allocate a ZIL
+ * block, and the given waiter must be linked to the "nolwb waiters"
+ * list inside of zil_process_commit_list().
+ */
+static void
+zil_commit_waiter_link_nolwb(zil_commit_waiter_t *zcw, list_t *nolwb)
+{
+ mutex_enter(&zcw->zcw_lock);
+ ASSERT(!list_link_active(&zcw->zcw_node));
+ ASSERT3P(zcw->zcw_lwb, ==, NULL);
+ list_insert_tail(nolwb, zcw);
+ mutex_exit(&zcw->zcw_lock);
}
void
-zil_add_block(zilog_t *zilog, const blkptr_t *bp)
+zil_lwb_add_block(lwb_t *lwb, const blkptr_t *bp)
{
- avl_tree_t *t = &zilog->zl_vdev_tree;
+ avl_tree_t *t = &lwb->lwb_vdev_tree;
avl_index_t where;
zil_vdev_node_t *zv, zvsearch;
int ndvas = BP_GET_NDVAS(bp);
@@ -841,14 +979,7 @@ zil_add_block(zilog_t *zilog, const blkptr_t *bp)
if (zfs_nocacheflush)
return;
- ASSERT(zilog->zl_writer);
-
- /*
- * Even though we're zl_writer, we still need a lock because the
- * zl_get_data() callbacks may have dmu_sync() done callbacks
- * that will run concurrently.
- */
- mutex_enter(&zilog->zl_vdev_lock);
+ mutex_enter(&lwb->lwb_vdev_lock);
for (i = 0; i < ndvas; i++) {
zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
if (avl_find(t, &zvsearch, &where) == NULL) {
@@ -857,56 +988,122 @@ zil_add_block(zilog_t *zilog, const blkptr_t *bp)
avl_insert(t, zv, where);
}
}
- mutex_exit(&zilog->zl_vdev_lock);
+ mutex_exit(&lwb->lwb_vdev_lock);
}
+void
+zil_lwb_add_txg(lwb_t *lwb, uint64_t txg)
+{
+ lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
+}
+
+/*
+ * This function is a called after all VDEVs associated with a given lwb
+ * write have completed their DKIOCFLUSHWRITECACHE command; or as soon
+ * as the lwb write completes, if "zfs_nocacheflush" is set.
+ *
+ * The intention is for this function to be called as soon as the
+ * contents of an lwb are considered "stable" on disk, and will survive
+ * any sudden loss of power. At this point, any threads waiting for the
+ * lwb to reach this state are signalled, and the "waiter" structures
+ * are marked "done".
+ */
static void
-zil_flush_vdevs(zilog_t *zilog)
+zil_lwb_flush_vdevs_done(zio_t *zio)
{
- spa_t *spa = zilog->zl_spa;
- avl_tree_t *t = &zilog->zl_vdev_tree;
- void *cookie = NULL;
- zil_vdev_node_t *zv;
- zio_t *zio;
+ lwb_t *lwb = zio->io_private;
+ zilog_t *zilog = lwb->lwb_zilog;
+ dmu_tx_t *tx = lwb->lwb_tx;
+ zil_commit_waiter_t *zcw;
+ itx_t *itx;
+
+ spa_config_exit(zilog->zl_spa, SCL_STATE, lwb);
+
+ zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
- ASSERT(zilog->zl_writer);
+ mutex_enter(&zilog->zl_lock);
/*
- * We don't need zl_vdev_lock here because we're the zl_writer,
- * and all zl_get_data() callbacks are done.
+ * Ensure the lwb buffer pointer is cleared before releasing the
+ * txg. If we have had an allocation failure and the txg is
+ * waiting to sync then we want zil_sync() to remove the lwb so
+ * that it's not picked up as the next new one in
+ * zil_process_commit_list(). zil_sync() will only remove the
+ * lwb if lwb_buf is null.
*/
- if (avl_numnodes(t) == 0)
- return;
+ lwb->lwb_buf = NULL;
+ lwb->lwb_tx = NULL;
- spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
+ ASSERT3U(lwb->lwb_issued_timestamp, >, 0);
+ zilog->zl_last_lwb_latency = gethrtime() - lwb->lwb_issued_timestamp;
- zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
+ lwb->lwb_root_zio = NULL;
+ lwb->lwb_state = LWB_STATE_DONE;
- while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
- vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
- if (vd != NULL)
- zio_flush(zio, vd);
- kmem_free(zv, sizeof (*zv));
+ if (zilog->zl_last_lwb_opened == lwb) {
+ /*
+ * Remember the highest committed log sequence number
+ * for ztest. We only update this value when all the log
+ * writes succeeded, because ztest wants to ASSERT that
+ * it got the whole log chain.
+ */
+ zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
+ }
+
+ while ((itx = list_head(&lwb->lwb_itxs)) != NULL) {
+ list_remove(&lwb->lwb_itxs, itx);
+ zil_itx_destroy(itx);
+ }
+
+ while ((zcw = list_head(&lwb->lwb_waiters)) != NULL) {
+ mutex_enter(&zcw->zcw_lock);
+
+ ASSERT(list_link_active(&zcw->zcw_node));
+ list_remove(&lwb->lwb_waiters, zcw);
+
+ ASSERT3P(zcw->zcw_lwb, ==, lwb);
+ zcw->zcw_lwb = NULL;
+
+ zcw->zcw_zio_error = zio->io_error;
+
+ ASSERT3B(zcw->zcw_done, ==, B_FALSE);
+ zcw->zcw_done = B_TRUE;
+ cv_broadcast(&zcw->zcw_cv);
+
+ mutex_exit(&zcw->zcw_lock);
}
+ mutex_exit(&zilog->zl_lock);
+
/*
- * Wait for all the flushes to complete. Not all devices actually
- * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
+ * Now that we've written this log block, we have a stable pointer
+ * to the next block in the chain, so it's OK to let the txg in
+ * which we allocated the next block sync.
*/
- (void) zio_wait(zio);
-
- spa_config_exit(spa, SCL_STATE, FTAG);
+ dmu_tx_commit(tx);
}
/*
- * Function called when a log block write completes
+ * This is called when an lwb write completes. This means, this specific
+ * lwb was written to disk, and all dependent lwb have also been
+ * written to disk.
+ *
+ * At this point, a DKIOCFLUSHWRITECACHE command hasn't been issued to
+ * the VDEVs involved in writing out this specific lwb. The lwb will be
+ * "done" once zil_lwb_flush_vdevs_done() is called, which occurs in the
+ * zio completion callback for the lwb's root zio.
*/
static void
zil_lwb_write_done(zio_t *zio)
{
lwb_t *lwb = zio->io_private;
+ spa_t *spa = zio->io_spa;
zilog_t *zilog = lwb->lwb_zilog;
- dmu_tx_t *tx = lwb->lwb_tx;
+ avl_tree_t *t = &lwb->lwb_vdev_tree;
+ void *cookie = NULL;
+ zil_vdev_node_t *zv;
+
+ ASSERT3S(spa_config_held(spa, SCL_STATE, RW_READER), !=, 0);
ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
@@ -916,69 +1113,121 @@ zil_lwb_write_done(zio_t *zio)
ASSERT(!BP_IS_HOLE(zio->io_bp));
ASSERT(BP_GET_FILL(zio->io_bp) == 0);
- /*
- * Ensure the lwb buffer pointer is cleared before releasing
- * the txg. If we have had an allocation failure and
- * the txg is waiting to sync then we want want zil_sync()
- * to remove the lwb so that it's not picked up as the next new
- * one in zil_commit_writer(). zil_sync() will only remove
- * the lwb if lwb_buf is null.
- */
abd_put(zio->io_abd);
- zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
+
+ ASSERT3S(lwb->lwb_state, ==, LWB_STATE_ISSUED);
+
mutex_enter(&zilog->zl_lock);
- lwb->lwb_zio = NULL;
+ lwb->lwb_write_zio = NULL;
lwb->lwb_fastwrite = FALSE;
- lwb->lwb_buf = NULL;
- lwb->lwb_tx = NULL;
mutex_exit(&zilog->zl_lock);
+ if (avl_numnodes(t) == 0)
+ return;
+
/*
- * Now that we've written this log block, we have a stable pointer
- * to the next block in the chain, so it's OK to let the txg in
- * which we allocated the next block sync.
+ * If there was an IO error, we're not going to call zio_flush()
+ * on these vdevs, so we simply empty the tree and free the
+ * nodes. We avoid calling zio_flush() since there isn't any
+ * good reason for doing so, after the lwb block failed to be
+ * written out.
*/
- dmu_tx_commit(tx);
+ if (zio->io_error != 0) {
+ while ((zv = avl_destroy_nodes(t, &cookie)) != NULL)
+ kmem_free(zv, sizeof (*zv));
+ return;
+ }
+
+ while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
+ vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
+ if (vd != NULL)
+ zio_flush(lwb->lwb_root_zio, vd);
+ kmem_free(zv, sizeof (*zv));
+ }
}
/*
- * Initialize the io for a log block.
+ * This function's purpose is to "open" an lwb such that it is ready to
+ * accept new itxs being committed to it. To do this, the lwb's zio
+ * structures are created, and linked to the lwb. This function is
+ * idempotent; if the passed in lwb has already been opened, this
+ * function is essentially a no-op.
*/
static void
-zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
+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));
+ 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);
+
SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
- if (zilog->zl_root_zio == NULL) {
- zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
- ZIO_FLAG_CANFAIL);
- }
-
/* Lock so zil_sync() doesn't fastwrite_unmark after zio is created */
mutex_enter(&zilog->zl_lock);
- if (lwb->lwb_zio == NULL) {
+ if (lwb->lwb_root_zio == NULL) {
abd_t *lwb_abd = abd_get_from_buf(lwb->lwb_buf,
BP_GET_LSIZE(&lwb->lwb_blk));
+
if (!lwb->lwb_fastwrite) {
metaslab_fastwrite_mark(zilog->zl_spa, &lwb->lwb_blk);
lwb->lwb_fastwrite = 1;
}
+
if (!lwb->lwb_slog || zilog->zl_cur_used <= zil_slog_bulk)
prio = ZIO_PRIORITY_SYNC_WRITE;
else
prio = ZIO_PRIORITY_ASYNC_WRITE;
- lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
- 0, &lwb->lwb_blk, lwb_abd, BP_GET_LSIZE(&lwb->lwb_blk),
- zil_lwb_write_done, lwb, prio,
- ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE |
+
+ lwb->lwb_root_zio = zio_root(zilog->zl_spa,
+ zil_lwb_flush_vdevs_done, lwb, ZIO_FLAG_CANFAIL);
+ ASSERT3P(lwb->lwb_root_zio, !=, NULL);
+
+ lwb->lwb_write_zio = zio_rewrite(lwb->lwb_root_zio,
+ zilog->zl_spa, 0, &lwb->lwb_blk, lwb_abd,
+ BP_GET_LSIZE(&lwb->lwb_blk), zil_lwb_write_done, lwb,
+ prio, ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE |
ZIO_FLAG_FASTWRITE, &zb);
+ ASSERT3P(lwb->lwb_write_zio, !=, NULL);
+
+ lwb->lwb_state = LWB_STATE_OPENED;
+
+ /*
+ * The zilog's "zl_last_lwb_opened" field is used to
+ * build the lwb/zio dependency chain, which is used to
+ * preserve the ordering of lwb completions that is
+ * required by the semantics of the ZIL. Each new lwb
+ * zio becomes a parent of the "previous" lwb zio, such
+ * that the new lwb's zio cannot complete until the
+ * "previous" lwb's zio completes.
+ *
+ * This is required by the semantics of zil_commit();
+ * the commit waiters attached to the lwbs will be woken
+ * in the lwb zio's completion callback, so this zio
+ * dependency graph ensures the waiters are woken in the
+ * correct order (the same order the lwbs were created).
+ */
+ lwb_t *last_lwb_opened = zilog->zl_last_lwb_opened;
+ if (last_lwb_opened != NULL &&
+ last_lwb_opened->lwb_state != LWB_STATE_DONE) {
+ ASSERT(last_lwb_opened->lwb_state == LWB_STATE_OPENED ||
+ last_lwb_opened->lwb_state == LWB_STATE_ISSUED);
+ ASSERT3P(last_lwb_opened->lwb_root_zio, !=, NULL);
+ zio_add_child(lwb->lwb_root_zio,
+ last_lwb_opened->lwb_root_zio);
+ }
+ zilog->zl_last_lwb_opened = lwb;
}
mutex_exit(&zilog->zl_lock);
+
+ ASSERT3P(lwb->lwb_root_zio, !=, NULL);
+ ASSERT3P(lwb->lwb_write_zio, !=, NULL);
+ ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED);
}
/*
@@ -1000,7 +1249,7 @@ uint64_t zil_block_buckets[] = {
* Calls are serialized.
*/
static lwb_t *
-zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
+zil_lwb_write_issue(zilog_t *zilog, lwb_t *lwb)
{
lwb_t *nlwb = NULL;
zil_chain_t *zilc;
@@ -1012,6 +1261,11 @@ zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
int i, error;
boolean_t slog;
+ ASSERT(MUTEX_HELD(&zilog->zl_writer_lock));
+ ASSERT3P(lwb->lwb_root_zio, !=, NULL);
+ ASSERT3P(lwb->lwb_write_zio, !=, NULL);
+ ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED);
+
if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
zilc = (zil_chain_t *)lwb->lwb_buf;
bp = &zilc->zc_next_blk;
@@ -1031,6 +1285,7 @@ zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
* We dirty the dataset to ensure that zil_sync() will be called
* to clean up in the event of allocation failure or I/O failure.
*/
+
tx = dmu_tx_create(zilog->zl_os);
/*
@@ -1046,7 +1301,7 @@ zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
*/
error = dmu_tx_assign(tx, TXG_WAITED);
if (error != 0) {
- ASSERT3S(error, ==, EIO);
+ ASSERT(error == EIO || error == ERESTART);
dmu_tx_abort(tx);
return (NULL);
}
@@ -1097,19 +1352,16 @@ zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
/*
- * Allocate a new log write buffer (lwb).
+ * Allocate a new log write block (lwb).
*/
nlwb = zil_alloc_lwb(zilog, bp, slog, txg, TRUE);
-
- /* Record the block for later vdev flushing */
- zil_add_block(zilog, &lwb->lwb_blk);
}
if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
/* For Slim ZIL only write what is used. */
wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
ASSERT3U(wsz, <=, lwb->lwb_sz);
- zio_shrink(lwb->lwb_zio, wsz);
+ zio_shrink(lwb->lwb_write_zio, wsz);
} else {
wsz = lwb->lwb_sz;
@@ -1124,7 +1376,14 @@ zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
*/
bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
- zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
+ spa_config_enter(zilog->zl_spa, SCL_STATE, lwb, RW_READER);
+
+ zil_lwb_add_block(lwb, &lwb->lwb_blk);
+ lwb->lwb_issued_timestamp = gethrtime();
+ lwb->lwb_state = LWB_STATE_ISSUED;
+
+ zio_nowait(lwb->lwb_root_zio);
+ zio_nowait(lwb->lwb_write_zio);
/*
* If there was an allocation failure then nlwb will be null which
@@ -1141,13 +1400,33 @@ zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
char *lr_buf;
uint64_t dlen, dnow, lwb_sp, reclen, txg;
- if (lwb == NULL)
- return (NULL);
+ ASSERT(MUTEX_HELD(&zilog->zl_writer_lock));
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3P(lwb->lwb_buf, !=, NULL);
+
+ zil_lwb_write_open(zilog, lwb);
- ASSERT(lwb->lwb_buf != NULL);
+ lrc = &itx->itx_lr;
+ lrw = (lr_write_t *)lrc;
+
+ /*
+ * A commit itx doesn't represent any on-disk state; instead
+ * it's simply used as a place holder on the commit list, and
+ * provides a mechanism for attaching a "commit waiter" onto the
+ * correct lwb (such that the waiter can be signalled upon
+ * completion of that lwb). Thus, we don't process this itx's
+ * log record if it's a commit itx (these itx's don't have log
+ * records), and instead link the itx's waiter onto the lwb's
+ * list of waiters.
+ *
+ * For more details, see the comment above zil_commit().
+ */
+ if (lrc->lrc_txtype == TX_COMMIT) {
+ zil_commit_waiter_link_lwb(itx->itx_private, lwb);
+ itx->itx_private = NULL;
+ return (lwb);
+ }
- lrc = &itx->itx_lr; /* Common log record inside itx. */
- lrw = (lr_write_t *)lrc; /* Write log record inside itx. */
if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) {
dlen = P2ROUNDUP_TYPED(
lrw->lr_length, sizeof (uint64_t), uint64_t);
@@ -1158,7 +1437,7 @@ zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
zilog->zl_cur_used += (reclen + dlen);
txg = lrc->lrc_txg;
- zil_lwb_write_init(zilog, lwb);
+ ASSERT3U(zilog->zl_cur_used, <, UINT64_MAX - (reclen + dlen));
cont:
/*
@@ -1169,10 +1448,10 @@ cont:
if (reclen > lwb_sp || (reclen + dlen > lwb_sp &&
lwb_sp < ZIL_MAX_WASTE_SPACE && (dlen % ZIL_MAX_LOG_DATA == 0 ||
lwb_sp < reclen + dlen % ZIL_MAX_LOG_DATA))) {
- lwb = zil_lwb_write_start(zilog, lwb);
+ lwb = zil_lwb_write_issue(zilog, lwb);
if (lwb == NULL)
return (NULL);
- zil_lwb_write_init(zilog, lwb);
+ zil_lwb_write_open(zilog, lwb);
ASSERT(LWB_EMPTY(lwb));
lwb_sp = lwb->lwb_sz - lwb->lwb_nused;
ASSERT3U(reclen + MIN(dlen, sizeof (uint64_t)), <=, lwb_sp);
@@ -1210,14 +1489,31 @@ cont:
ZIL_STAT_INCR(zil_itx_needcopy_bytes,
lrw->lr_length);
} else {
- ASSERT(itx->itx_wr_state == WR_INDIRECT);
+ ASSERT3S(itx->itx_wr_state, ==, WR_INDIRECT);
dbuf = NULL;
ZIL_STAT_BUMP(zil_itx_indirect_count);
ZIL_STAT_INCR(zil_itx_indirect_bytes,
lrw->lr_length);
}
- error = zilog->zl_get_data(
- itx->itx_private, lrwb, dbuf, lwb->lwb_zio);
+
+ /*
+ * We pass in the "lwb_write_zio" rather than
+ * "lwb_root_zio" so that the "lwb_write_zio"
+ * becomes the parent of any zio's created by
+ * the "zl_get_data" callback. The vdevs are
+ * flushed after the "lwb_write_zio" completes,
+ * so we want to make sure that completion
+ * callback waits for these additional zio's,
+ * such that the vdevs used by those zio's will
+ * be included in the lwb's vdev tree, and those
+ * vdevs will be properly flushed. If we passed
+ * in "lwb_root_zio" here, then these additional
+ * vdevs may not be flushed; e.g. if these zio's
+ * completed after "lwb_write_zio" completed.
+ */
+ error = zilog->zl_get_data(itx->itx_private,
+ lrwb, dbuf, lwb, lwb->lwb_write_zio);
+
if (error == EIO) {
txg_wait_synced(zilog->zl_dmu_pool, txg);
return (lwb);
@@ -1236,9 +1532,11 @@ cont:
* equal to the itx sequence number because not all transactions
* are synchronous, and sometimes spa_sync() gets there first.
*/
- lrcb->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
+ lrcb->lrc_seq = ++zilog->zl_lr_seq;
lwb->lwb_nused += reclen + dnow;
- lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
+
+ zil_lwb_add_txg(lwb, txg);
+
ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
@@ -1275,6 +1573,12 @@ zil_itx_create(uint64_t txtype, size_t lrsize)
void
zil_itx_destroy(itx_t *itx)
{
+ IMPLY(itx->itx_lr.lrc_txtype == TX_COMMIT, itx->itx_callback == NULL);
+ IMPLY(itx->itx_callback != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT);
+
+ if (itx->itx_callback != NULL)
+ itx->itx_callback(itx->itx_callback_data);
+
zio_data_buf_free(itx, itx->itx_size);
}
@@ -1293,8 +1597,28 @@ zil_itxg_clean(itxs_t *itxs)
list = &itxs->i_sync_list;
while ((itx = list_head(list)) != NULL) {
- if (itx->itx_callback != NULL)
- itx->itx_callback(itx->itx_callback_data);
+ /*
+ * In the general case, commit itxs will not be found
+ * here, as they'll be committed to an lwb via
+ * zil_lwb_commit(), and free'd in that function. Having
+ * said that, it is still possible for commit itxs to be
+ * found here, due to the following race:
+ *
+ * - a thread calls zil_commit() which assigns the
+ * commit itx to a per-txg i_sync_list
+ * - zil_itxg_clean() is called (e.g. via spa_sync())
+ * while the waiter is still on the i_sync_list
+ *
+ * There's nothing to prevent syncing the txg while the
+ * waiter is on the i_sync_list. This normally doesn't
+ * happen because spa_sync() is slower than zil_commit(),
+ * but if zil_commit() calls txg_wait_synced() (e.g.
+ * because zil_create() or zil_commit_writer_stall() is
+ * called) we will hit this case.
+ */
+ if (itx->itx_lr.lrc_txtype == TX_COMMIT)
+ zil_commit_waiter_skip(itx->itx_private);
+
list_remove(list, itx);
zil_itx_destroy(itx);
}
@@ -1304,9 +1628,9 @@ zil_itxg_clean(itxs_t *itxs)
while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
list = &ian->ia_list;
while ((itx = list_head(list)) != NULL) {
- if (itx->itx_callback != NULL)
- itx->itx_callback(itx->itx_callback_data);
list_remove(list, itx);
+ /* commit itxs should never be on the async lists. */
+ ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT);
zil_itx_destroy(itx);
}
list_destroy(list);
@@ -1366,9 +1690,9 @@ zil_remove_async(zilog_t *zilog, uint64_t oid)
mutex_exit(&itxg->itxg_lock);
}
while ((itx = list_head(&clean_list)) != NULL) {
- if (itx->itx_callback != NULL)
- itx->itx_callback(itx->itx_callback_data);
list_remove(&clean_list, itx);
+ /* commit itxs should never be on the async lists. */
+ ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT);
zil_itx_destroy(itx);
}
list_destroy(&clean_list);
@@ -1448,7 +1772,14 @@ zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
}
itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
- zilog_dirty(zilog, txg);
+
+ /*
+ * We don't want to dirty the ZIL using ZILTEST_TXG, because
+ * zil_clean() will never be called using ZILTEST_TXG. Thus, we
+ * need to be careful to always dirty the ZIL using the "real"
+ * TXG (not itxg_txg) even when the SPA is frozen.
+ */
+ zilog_dirty(zilog, dmu_tx_get_txg(tx));
mutex_exit(&itxg->itxg_lock);
/* Release the old itxs now we've dropped the lock */
@@ -1469,6 +1800,8 @@ zil_clean(zilog_t *zilog, uint64_t synced_txg)
itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
itxs_t *clean_me;
+ ASSERT3U(synced_txg, <, ZILTEST_TXG);
+
mutex_enter(&itxg->itxg_lock);
if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
mutex_exit(&itxg->itxg_lock);
@@ -1495,7 +1828,8 @@ zil_clean(zilog_t *zilog, uint64_t synced_txg)
}
/*
- * Get the list of itxs to commit into zl_itx_commit_list.
+ * This function will traverse the queue of itxs that need to be
+ * committed, and move them onto the ZIL's zl_itx_commit_list.
*/
static void
zil_get_commit_list(zilog_t *zilog)
@@ -1503,6 +1837,8 @@ 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));
+
if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
otxg = ZILTEST_TXG;
else
@@ -1594,154 +1930,809 @@ zil_async_to_sync(zilog_t *zilog, uint64_t foid)
}
}
+/*
+ * This function will prune commit itxs that are at the head of the
+ * commit list (it won't prune past the first non-commit itx), and
+ * either: a) attach them to the last lwb that's still pending
+ * completion, or b) skip them altogether.
+ *
+ * This is used as a performance optimization to prevent commit itxs
+ * from generating new lwbs when it's unnecessary to do so.
+ */
static void
-zil_commit_writer(zilog_t *zilog)
+zil_prune_commit_list(zilog_t *zilog)
{
- uint64_t txg;
itx_t *itx;
- lwb_t *lwb;
- spa_t *spa = zilog->zl_spa;
- int error = 0;
- ASSERT(zilog->zl_root_zio == NULL);
+ ASSERT(MUTEX_HELD(&zilog->zl_writer_lock));
- mutex_exit(&zilog->zl_lock);
+ while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) {
+ lr_t *lrc = &itx->itx_lr;
+ if (lrc->lrc_txtype != TX_COMMIT)
+ break;
- zil_get_commit_list(zilog);
+ mutex_enter(&zilog->zl_lock);
+
+ lwb_t *last_lwb = zilog->zl_last_lwb_opened;
+ if (last_lwb == NULL || last_lwb->lwb_state == LWB_STATE_DONE) {
+ /*
+ * All of the itxs this waiter was waiting on
+ * must have already completed (or there were
+ * never any itx's for it to wait on), so it's
+ * safe to skip this waiter and mark it done.
+ */
+ zil_commit_waiter_skip(itx->itx_private);
+ } else {
+ zil_commit_waiter_link_lwb(itx->itx_private, last_lwb);
+ itx->itx_private = NULL;
+ }
+
+ mutex_exit(&zilog->zl_lock);
+
+ list_remove(&zilog->zl_itx_commit_list, itx);
+ zil_itx_destroy(itx);
+ }
+
+ IMPLY(itx != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT);
+}
+
+static void
+zil_commit_writer_stall(zilog_t *zilog)
+{
+ /*
+ * When zio_alloc_zil() fails to allocate the next lwb block on
+ * disk, we must call txg_wait_synced() to ensure all of the
+ * lwbs in the zilog's zl_lwb_list are synced and then freed (in
+ * zil_sync()), such that any subsequent ZIL writer (i.e. a call
+ * to zil_process_commit_list()) will have to call zil_create(),
+ * and start a new ZIL chain.
+ *
+ * Since zil_alloc_zil() failed, the lwb that was previously
+ * issued does not have a pointer to the "next" lwb on disk.
+ * Thus, if another ZIL writer thread was to allocate the "next"
+ * on-disk lwb, that block could be leaked in the event of a
+ * 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
+ * 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));
+ txg_wait_synced(zilog->zl_dmu_pool, 0);
+ ASSERT3P(list_tail(&zilog->zl_lwb_list), ==, NULL);
+}
+
+/*
+ * This function will traverse the commit list, creating new lwbs as
+ * needed, and committing the itxs from the commit list to these newly
+ * created lwbs. Additionally, as a new lwb is created, the previous
+ * lwb will be issued to the zio layer to be written to disk.
+ */
+static void
+zil_process_commit_list(zilog_t *zilog)
+{
+ spa_t *spa = zilog->zl_spa;
+ list_t nolwb_itxs;
+ list_t nolwb_waiters;
+ lwb_t *lwb;
+ itx_t *itx;
+
+ ASSERT(MUTEX_HELD(&zilog->zl_writer_lock));
/*
* Return if there's nothing to commit before we dirty the fs by
* calling zil_create().
*/
- if (list_head(&zilog->zl_itx_commit_list) == NULL) {
- mutex_enter(&zilog->zl_lock);
+ if (list_head(&zilog->zl_itx_commit_list) == NULL)
return;
- }
- if (zilog->zl_suspend) {
- lwb = NULL;
+ list_create(&nolwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node));
+ list_create(&nolwb_waiters, sizeof (zil_commit_waiter_t),
+ offsetof(zil_commit_waiter_t, zcw_node));
+
+ lwb = list_tail(&zilog->zl_lwb_list);
+ if (lwb == NULL) {
+ lwb = zil_create(zilog);
} else {
- lwb = list_tail(&zilog->zl_lwb_list);
- if (lwb == NULL)
- lwb = zil_create(zilog);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_DONE);
}
- DTRACE_PROBE1(zil__cw1, 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;
+ while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) {
+ lr_t *lrc = &itx->itx_lr;
+ uint64_t txg = lrc->lrc_txg;
+
ASSERT3U(txg, !=, 0);
+ if (lrc->lrc_txtype == TX_COMMIT) {
+ DTRACE_PROBE2(zil__process__commit__itx,
+ zilog_t *, zilog, itx_t *, itx);
+ } else {
+ DTRACE_PROBE2(zil__process__normal__itx,
+ zilog_t *, zilog, itx_t *, itx);
+ }
+
+ list_remove(&zilog->zl_itx_commit_list, itx);
+
/*
* 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().
+ * 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);
+ boolean_t synced = txg <= spa_last_synced_txg(spa);
+ boolean_t frozen = txg > spa_freeze_txg(spa);
+
+ if (!synced || frozen) {
+ if (lwb != NULL) {
+ lwb = zil_lwb_commit(zilog, itx, lwb);
+
+ if (lwb == NULL)
+ list_insert_tail(&nolwb_itxs, itx);
+ else
+ list_insert_tail(&lwb->lwb_itxs, itx);
+ } else {
+ if (lrc->lrc_txtype == TX_COMMIT) {
+ zil_commit_waiter_link_nolwb(
+ itx->itx_private, &nolwb_waiters);
+ }
+
+ list_insert_tail(&nolwb_itxs, itx);
+ }
+ } else {
+ /*
+ * If this is a commit itx, then there will be a
+ * thread that is either: already waiting for
+ * it, or soon will be waiting.
+ *
+ * This itx has already been committed to disk
+ * via spa_sync() so we don't bother committing
+ * it to an lwb. As a result, we cannot use the
+ * lwb zio callback to signal the waiter and
+ * mark it as done, so we must do that here.
+ */
+ if (lrc->lrc_txtype == TX_COMMIT)
+ zil_commit_waiter_skip(itx->itx_private);
+
+ zil_itx_destroy(itx);
+ }
}
- DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
- /* write the last block out */
- if (lwb != NULL && lwb->lwb_zio != NULL)
- lwb = zil_lwb_write_start(zilog, lwb);
+ if (lwb == NULL) {
+ /*
+ * This indicates zio_alloc_zil() failed to allocate the
+ * "next" lwb on-disk. When this happens, we must stall
+ * the ZIL write pipeline; see the comment within
+ * zil_commit_writer_stall() for more details.
+ */
+ zil_commit_writer_stall(zilog);
- zilog->zl_cur_used = 0;
+ /*
+ * Additionally, we have to signal and mark the "nolwb"
+ * waiters as "done" here, since without an lwb, we
+ * can't do this via zil_lwb_flush_vdevs_done() like
+ * normal.
+ */
+ zil_commit_waiter_t *zcw;
+ while ((zcw = list_head(&nolwb_waiters)) != NULL) {
+ zil_commit_waiter_skip(zcw);
+ list_remove(&nolwb_waiters, zcw);
+ }
+
+ /*
+ * And finally, we have to destroy the itx's that
+ * couldn't be committed to an lwb; this will also call
+ * the itx's callback if one exists for the itx.
+ */
+ while ((itx = list_head(&nolwb_itxs)) != NULL) {
+ list_remove(&nolwb_itxs, itx);
+ zil_itx_destroy(itx);
+ }
+ } else {
+ ASSERT(list_is_empty(&nolwb_waiters));
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_DONE);
+
+ /*
+ * At this point, the ZIL block pointed at by the "lwb"
+ * variable is in one of the following states: "closed"
+ * or "open".
+ *
+ * If its "closed", then no itxs have been committed to
+ * it, so there's no point in issueing its zio (i.e.
+ * it's "empty").
+ *
+ * If its "open" state, then it contains one or more
+ * itxs that eventually need to be committed to stable
+ * storage. In this case we intentionally do not issue
+ * the lwb's zio to disk yet, and instead rely on one of
+ * the following two mechanisms for issuing the zio:
+ *
+ * 1. Ideally, there will be more ZIL activity occuring
+ * on the system, such that this function will be
+ * immeidately called again (not necessarily by the same
+ * thread) and this lwb's zio will be issued via
+ * zil_lwb_commit(). This way, the lwb is guaranteed to
+ * be "full" when it is issued to disk, and we'll make
+ * use of the lwb's size the best we can.
+ *
+ * 2. If there isn't sufficient ZIL activity occuring on
+ * the system, such that this lwb's zio isn't issued via
+ * zil_lwb_commit(), zil_commit_waiter() will issue the
+ * lwb's zio. If this occurs, the lwb is not guaranteed
+ * to be "full" by the time its zio is issued, and means
+ * the size of the lwb was "too large" given the amount
+ * of ZIL activity occuring on the system at that time.
+ *
+ * We do this for a couple of reasons:
+ *
+ * 1. To try and reduce the number of IOPs needed to
+ * write the same number of itxs. If an lwb has space
+ * available in it's buffer for more itxs, and more itxs
+ * will be committed relatively soon (relative to the
+ * latency of performing a write), then it's beneficial
+ * to wait for these "next" itxs. This way, more itxs
+ * can be committed to stable storage with fewer writes.
+ *
+ * 2. To try and use the largest lwb block size that the
+ * incoming rate of itxs can support. Again, this is to
+ * try and pack as many itxs into as few lwbs as
+ * possible, without significantly impacting the latency
+ * of each individual itx.
+ */
+ }
+}
+
+/*
+ * This function is responsible for ensuring the passed in commit waiter
+ * (and associated commit itx) is committed to an lwb. If the waiter is
+ * not already committed to an lwb, all itxs in the zilog's queue of
+ * itxs will be processed. The assumption is the passed in waiter's
+ * commit itx will found in the queue just like the other non-commit
+ * itxs, such that when the entire queue is processed, the waiter will
+ * have been commited to an lwb.
+ *
+ * The lwb associated with the passed in waiter is not guaranteed to
+ * have been issued by the time this function completes. If the lwb is
+ * not issued, we rely on future calls to zil_commit_writer() to issue
+ * the lwb, or the timeout mechanism found in zil_commit_waiter().
+ */
+static void
+zil_commit_writer(zilog_t *zilog, zil_commit_waiter_t *zcw)
+{
+ ASSERT(!MUTEX_HELD(&zilog->zl_lock));
+ ASSERT(spa_writeable(zilog->zl_spa));
+ ASSERT0(zilog->zl_suspend);
+
+ mutex_enter(&zilog->zl_writer_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
+ * 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
+ * attempt to reduce this contention, we immediately drop
+ * the lock if the waiter has already been processed.
+ *
+ * We've measured this optimization to reduce CPU spent
+ * contending on this lock by up to 5%, using a system
+ * with 32 CPUs, low latency storage (~50 usec writes),
+ * and 1024 threads performing sync writes.
+ */
+ goto out;
+ }
+
+ ZIL_STAT_BUMP(zil_commit_writer_count);
+
+ zil_get_commit_list(zilog);
+ zil_prune_commit_list(zilog);
+ zil_process_commit_list(zilog);
+
+out:
+ mutex_exit(&zilog->zl_writer_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(&zcw->zcw_lock));
+ ASSERT3B(zcw->zcw_done, ==, B_FALSE);
+
+ lwb_t *lwb = zcw->zcw_lwb;
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_CLOSED);
/*
- * Wait if necessary for the log blocks to be on stable storage.
+ * 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
+ * acquiring it when it's not necessary to do so.
*/
- if (zilog->zl_root_zio) {
- error = zio_wait(zilog->zl_root_zio);
- zilog->zl_root_zio = NULL;
- zil_flush_vdevs(zilog);
- }
+ if (lwb->lwb_state == LWB_STATE_ISSUED ||
+ lwb->lwb_state == LWB_STATE_DONE)
+ return;
- if (error || lwb == NULL)
- txg_wait_synced(zilog->zl_dmu_pool, 0);
+ /*
+ * In order to call zil_lwb_write_issue() we must hold the
+ * zilog's "zl_writer_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(&zcw->zcw_lock);
- while ((itx = list_head(&zilog->zl_itx_commit_list))) {
- txg = itx->itx_lr.lrc_txg;
- ASSERT(txg);
+ /*
+ * Since we just dropped and re-acquired the commit waiter's
+ * lock, we have to re-check to see if the waiter was marked
+ * "done" during that process. If the waiter was marked "done",
+ * the "lwb" pointer is no longer valid (it can be free'd after
+ * the waiter is marked "done"), so without this check we could
+ * wind up with a use-after-free error below.
+ */
+ if (zcw->zcw_done)
+ goto out;
- if (itx->itx_callback != NULL)
- itx->itx_callback(itx->itx_callback_data);
- list_remove(&zilog->zl_itx_commit_list, itx);
- zil_itx_destroy(itx);
+ ASSERT3P(lwb, ==, zcw->zcw_lwb);
+
+ /*
+ * We've already checked this above, but since we hadn't
+ * acquired the zilog's zl_writer_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.
+ */
+ if (lwb->lwb_state == LWB_STATE_ISSUED ||
+ lwb->lwb_state == LWB_STATE_DONE)
+ goto out;
+
+ ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED);
+
+ /*
+ * As described in the comments above zil_commit_waiter() and
+ * zil_process_commit_list(), we need to issue this lwb's zio
+ * since we've reached the commit waiter's timeout and it still
+ * hasn't been issued.
+ */
+ lwb_t *nlwb = zil_lwb_write_issue(zilog, lwb);
+
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_OPENED);
+
+ /*
+ * Since the lwb's zio hadn't been issued by the time this thread
+ * reached its timeout, we reset the zilog's "zl_cur_used" field
+ * to influence the zil block size selection algorithm.
+ *
+ * By having to issue the lwb's zio here, it means the size of the
+ * lwb was too large, given the incoming throughput of itxs. By
+ * setting "zl_cur_used" to zero, we communicate this fact to the
+ * block size selection algorithm, so it can take this informaiton
+ * into account, and potentially select a smaller size for the
+ * next lwb block that is allocated.
+ */
+ zilog->zl_cur_used = 0;
+
+ if (nlwb == NULL) {
+ /*
+ * When zil_lwb_write_issue() returns NULL, this
+ * indicates zio_alloc_zil() failed to allocate the
+ * "next" lwb on-disk. When this occurs, the ZIL write
+ * pipeline must be stalled; see the comment within the
+ * zil_commit_writer_stall() function for more details.
+ *
+ * We must drop the commit waiter's lock prior to
+ * calling zil_commit_writer_stall() or else we can wind
+ * up with the following deadlock:
+ *
+ * - This thread is waiting for the txg to sync while
+ * holding the waiter's lock; txg_wait_synced() is
+ * used within txg_commit_writer_stall().
+ *
+ * - The txg can't sync because it is waiting for this
+ * lwb's zio callback to call dmu_tx_commit().
+ *
+ * - The lwb's zio callback can't call dmu_tx_commit()
+ * because it's blocked trying to acquire the waiter's
+ * lock, which occurs prior to calling dmu_tx_commit()
+ */
+ mutex_exit(&zcw->zcw_lock);
+ zil_commit_writer_stall(zilog);
+ mutex_enter(&zcw->zcw_lock);
}
- mutex_enter(&zilog->zl_lock);
+out:
+ mutex_exit(&zilog->zl_writer_lock);
+ ASSERT(MUTEX_HELD(&zcw->zcw_lock));
+}
+
+/*
+ * This function is responsible for performing the following two tasks:
+ *
+ * 1. its primary responsibility is to block until the given "commit
+ * waiter" is considered "done".
+ *
+ * 2. its secondary responsibility is to issue the zio for the lwb that
+ * the given "commit waiter" is waiting on, if this function has
+ * waited "long enough" and the lwb is still in the "open" state.
+ *
+ * Given a sufficient amount of itxs being generated and written using
+ * the ZIL, the lwb's zio will be issued via the zil_lwb_commit()
+ * function. If this does not occur, this secondary responsibility will
+ * ensure the lwb is issued even if there is not other synchronous
+ * activity on the system.
+ *
+ * For more details, see zil_process_commit_list(); more specifically,
+ * the comment at the bottom of that function.
+ */
+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(spa_writeable(zilog->zl_spa));
+ ASSERT0(zilog->zl_suspend);
+
+ mutex_enter(&zcw->zcw_lock);
/*
- * Remember the highest committed log sequence number for ztest.
- * We only update this value when all the log writes succeeded,
- * because ztest wants to ASSERT that it got the whole log chain.
+ * The timeout is scaled based on the lwb latency to avoid
+ * significantly impacting the latency of each individual itx.
+ * For more details, see the comment at the bottom of the
+ * zil_process_commit_list() function.
*/
- if (error == 0 && lwb != NULL)
- zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
+ int pct = MAX(zfs_commit_timeout_pct, 1);
+ hrtime_t sleep = (zilog->zl_last_lwb_latency * pct) / 100;
+ hrtime_t wakeup = gethrtime() + sleep;
+ boolean_t timedout = B_FALSE;
+
+ while (!zcw->zcw_done) {
+ ASSERT(MUTEX_HELD(&zcw->zcw_lock));
+
+ lwb_t *lwb = zcw->zcw_lwb;
+
+ /*
+ * Usually, the waiter will have a non-NULL lwb field here,
+ * but it's possible for it to be NULL as a result of
+ * zil_commit() racing with spa_sync().
+ *
+ * When zil_clean() is called, it's possible for the itxg
+ * list (which may be cleaned via a taskq) to contain
+ * commit itxs. When this occurs, the commit waiters linked
+ * off of these commit itxs will not be committed to an
+ * lwb. Additionally, these commit waiters will not be
+ * marked done until zil_commit_waiter_skip() is called via
+ * zil_itxg_clean().
+ *
+ * Thus, it's possible for this commit waiter (i.e. the
+ * "zcw" variable) to be found in this "in between" state;
+ * where it's "zcw_lwb" field is NULL, and it hasn't yet
+ * been skipped, so it's "zcw_done" field is still B_FALSE.
+ */
+ IMPLY(lwb != NULL, lwb->lwb_state != LWB_STATE_CLOSED);
+
+ if (lwb != NULL && lwb->lwb_state == LWB_STATE_OPENED) {
+ ASSERT3B(timedout, ==, B_FALSE);
+
+ /*
+ * If the lwb hasn't been issued yet, then we
+ * need to wait with a timeout, in case this
+ * function needs to issue the lwb after the
+ * timeout is reached; responsibility (2) from
+ * the comment above this function.
+ */
+ clock_t timeleft = cv_timedwait_hires(&zcw->zcw_cv,
+ &zcw->zcw_lock, wakeup, USEC2NSEC(1),
+ CALLOUT_FLAG_ABSOLUTE);
+
+ if (timeleft >= 0 || zcw->zcw_done)
+ continue;
+
+ timedout = B_TRUE;
+ zil_commit_waiter_timeout(zilog, zcw);
+
+ if (!zcw->zcw_done) {
+ /*
+ * If the commit waiter has already been
+ * marked "done", it's possible for the
+ * waiter's lwb structure to have already
+ * been freed. Thus, we can only reliably
+ * make these assertions if the waiter
+ * isn't done.
+ */
+ ASSERT3P(lwb, ==, zcw->zcw_lwb);
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_OPENED);
+ }
+ } else {
+ /*
+ * If the lwb isn't open, then it must have already
+ * been issued. In that case, there's no need to
+ * use a timeout when waiting for the lwb to
+ * complete.
+ *
+ * Additionally, if the lwb is NULL, the waiter
+ * will soon be signalled and marked done via
+ * zil_clean() and zil_itxg_clean(), so no timeout
+ * is required.
+ */
+
+ IMPLY(lwb != NULL,
+ lwb->lwb_state == LWB_STATE_ISSUED ||
+ lwb->lwb_state == LWB_STATE_DONE);
+ cv_wait(&zcw->zcw_cv, &zcw->zcw_lock);
+ }
+ }
+
+ mutex_exit(&zcw->zcw_lock);
+}
+
+static zil_commit_waiter_t *
+zil_alloc_commit_waiter(void)
+{
+ zil_commit_waiter_t *zcw = kmem_cache_alloc(zil_zcw_cache, KM_SLEEP);
+
+ cv_init(&zcw->zcw_cv, NULL, CV_DEFAULT, NULL);
+ mutex_init(&zcw->zcw_lock, NULL, MUTEX_DEFAULT, NULL);
+ list_link_init(&zcw->zcw_node);
+ zcw->zcw_lwb = NULL;
+ zcw->zcw_done = B_FALSE;
+ zcw->zcw_zio_error = 0;
+
+ return (zcw);
+}
+
+static void
+zil_free_commit_waiter(zil_commit_waiter_t *zcw)
+{
+ ASSERT(!list_link_active(&zcw->zcw_node));
+ ASSERT3P(zcw->zcw_lwb, ==, NULL);
+ ASSERT3B(zcw->zcw_done, ==, B_TRUE);
+ mutex_destroy(&zcw->zcw_lock);
+ cv_destroy(&zcw->zcw_cv);
+ kmem_cache_free(zil_zcw_cache, zcw);
}
/*
- * Commit zfs transactions to stable storage.
- * If foid is 0 push out all transactions, otherwise push only those
- * for that object or might reference that object.
+ * This function is used to create a TX_COMMIT itx and assign it. This
+ * way, it will be linked into the ZIL's list of synchronous itxs, and
+ * then later committed to an lwb (or skipped) when
+ * zil_process_commit_list() is called.
+ */
+static void
+zil_commit_itx_assign(zilog_t *zilog, zil_commit_waiter_t *zcw)
+{
+ dmu_tx_t *tx = dmu_tx_create(zilog->zl_os);
+ VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
+
+ itx_t *itx = zil_itx_create(TX_COMMIT, sizeof (lr_t));
+ itx->itx_sync = B_TRUE;
+ itx->itx_private = zcw;
+
+ zil_itx_assign(zilog, itx, tx);
+
+ dmu_tx_commit(tx);
+}
+
+/*
+ * Commit ZFS Intent Log transactions (itxs) to stable storage.
+ *
+ * When writing ZIL transactions to the on-disk representation of the
+ * ZIL, the itxs are committed to a Log Write Block (lwb). Multiple
+ * itxs can be committed to a single lwb. Once a lwb is written and
+ * committed to stable storage (i.e. the lwb is written, and vdevs have
+ * been flushed), each itx that was committed to that lwb is also
+ * considered to be committed to stable storage.
+ *
+ * When an itx is committed to an lwb, the log record (lr_t) contained
+ * by the itx is copied into the lwb's zio buffer, and once this buffer
+ * is written to disk, it becomes an on-disk ZIL block.
+ *
+ * As itxs are generated, they're inserted into the ZIL's queue of
+ * uncommitted itxs. The semantics of zil_commit() are such that it will
+ * block until all itxs that were in the queue when it was called, are
+ * committed to stable storage.
+ *
+ * If "foid" is zero, this means all "synchronous" and "asynchronous"
+ * itxs, for all objects in the dataset, will be committed to stable
+ * storage prior to zil_commit() returning. If "foid" is non-zero, all
+ * "synchronous" itxs for all objects, but only "asynchronous" itxs
+ * that correspond to the foid passed in, will be committed to stable
+ * storage prior to zil_commit() returning.
+ *
+ * Generally speaking, when zil_commit() is called, the consumer doesn't
+ * actually care about _all_ of the uncommitted itxs. Instead, they're
+ * simply trying to waiting for a specific itx to be committed to disk,
+ * but the interface(s) for interacting with the ZIL don't allow such
+ * fine-grained communication. A better interface would allow a consumer
+ * to create and assign an itx, and then pass a reference to this itx to
+ * zil_commit(); such that zil_commit() would return as soon as that
+ * specific itx was committed to disk (instead of waiting for _all_
+ * itxs to be committed).
+ *
+ * When a thread calls zil_commit() a special "commit itx" will be
+ * generated, along with a corresponding "waiter" for this commit itx.
+ * zil_commit() will wait on this waiter's CV, such that when the waiter
+ * is marked done, and signalled, zil_commit() will return.
+ *
+ * This commit itx is inserted into the queue of uncommitted itxs. This
+ * provides an easy mechanism for determining which itxs were in the
+ * queue prior to zil_commit() having been called, and which itxs were
+ * added after zil_commit() was called.
+ *
+ * The commit it is special; it doesn't have any on-disk representation.
+ * When a commit itx is "committed" to an lwb, the waiter associated
+ * with it is linked onto the lwb's list of waiters. Then, when that lwb
+ * completes, each waiter on the lwb's list is marked done and signalled
+ * -- allowing the thread waiting on the waiter to return from zil_commit().
+ *
+ * It's important to point out a few critical factors that allow us
+ * to make use of the commit itxs, commit waiters, per-lwb lists of
+ * commit waiters, and zio completion callbacks like we're doing:
*
- * itxs are committed in batches. In a heavily stressed zil there will be
- * a commit writer thread who is writing out a bunch of itxs to the log
- * for a set of committing threads (cthreads) in the same batch as the writer.
- * Those cthreads are all waiting on the same cv for that batch.
+ * 1. The list of waiters for each lwb is traversed, and each commit
+ * waiter is marked "done" and signalled, in the zio completion
+ * callback of the lwb's zio[*].
*
- * There will also be a different and growing batch of threads that are
- * waiting to commit (qthreads). When the committing batch completes
- * a transition occurs such that the cthreads exit and the qthreads become
- * cthreads. One of the new cthreads becomes the writer thread for the
- * batch. Any new threads arriving become new qthreads.
+ * * Actually, the waiters are signalled in the zio completion
+ * callback of the root zio for the DKIOCFLUSHWRITECACHE commands
+ * that are sent to the vdevs upon completion of the lwb zio.
*
- * Only 2 condition variables are needed and there's no transition
- * between the two cvs needed. They just flip-flop between qthreads
- * and cthreads.
+ * 2. When the itxs are inserted into the ZIL's queue of uncommitted
+ * itxs, the order in which they are inserted is preserved[*]; as
+ * itxs are added to the queue, they are added to the tail of
+ * in-memory linked lists.
*
- * Using this scheme we can efficiently wakeup up only those threads
- * that have been committed.
+ * When committing the itxs to lwbs (to be written to disk), they
+ * are committed in the same order in which the itxs were added to
+ * the uncommitted queue's linked list(s); i.e. the linked list of
+ * itxs to commit is traversed from head to tail, and each itx is
+ * committed to an lwb in that order.
+ *
+ * * To clarify:
+ *
+ * - the order of "sync" itxs is preserved w.r.t. other
+ * "sync" itxs, regardless of the corresponding objects.
+ * - the order of "async" itxs is preserved w.r.t. other
+ * "async" itxs corresponding to the same object.
+ * - the order of "async" itxs is *not* preserved w.r.t. other
+ * "async" itxs corresponding to different objects.
+ * - the order of "sync" itxs w.r.t. "async" itxs (or vice
+ * versa) is *not* preserved, even for itxs that correspond
+ * to the same object.
+ *
+ * For more details, see: zil_itx_assign(), zil_async_to_sync(),
+ * zil_get_commit_list(), and zil_process_commit_list().
+ *
+ * 3. The lwbs represent a linked list of blocks on disk. Thus, any
+ * lwb cannot be considered committed to stable storage, until its
+ * "previous" lwb is also committed to stable storage. This fact,
+ * coupled with the fact described above, means that itxs are
+ * committed in (roughly) the order in which they were generated.
+ * This is essential because itxs are dependent on prior itxs.
+ * Thus, we *must not* deem an itx as being committed to stable
+ * storage, until *all* prior itxs have also been committed to
+ * stable storage.
+ *
+ * To enforce this ordering of lwb zio's, while still leveraging as
+ * much of the underlying storage performance as possible, we rely
+ * 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
+ * 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)
+ *
+ * By relying on this parent-child zio relationship, we can have
+ * many lwb zio's concurrently issued to the underlying storage,
+ * but the order in which they complete will be the same order in
+ * which they were created.
*/
void
zil_commit(zilog_t *zilog, uint64_t foid)
{
- uint64_t mybatch;
+ /*
+ * We should never attempt to call zil_commit on a snapshot for
+ * a couple of reasons:
+ *
+ * 1. A snapshot may never be modified, thus it cannot have any
+ * in-flight itxs that would have modified the dataset.
+ *
+ * 2. By design, when zil_commit() is called, a commit itx will
+ * be assigned to this zilog; as a result, the zilog will be
+ * dirtied. We must not dirty the zilog of a snapshot; there's
+ * checks in the code that enforce this invariant, and will
+ * cause a panic if it's not upheld.
+ */
+ ASSERT3B(dmu_objset_is_snapshot(zilog->zl_os), ==, B_FALSE);
if (zilog->zl_sync == ZFS_SYNC_DISABLED)
return;
+ if (!spa_writeable(zilog->zl_spa)) {
+ /*
+ * If the SPA is not writable, there should never be any
+ * pending itxs waiting to be committed to disk. If that
+ * weren't true, we'd skip writing those itxs out, and
+ * would break the sematics of zil_commit(); thus, we're
+ * verifying that truth before we return to the caller.
+ */
+ ASSERT(list_is_empty(&zilog->zl_lwb_list));
+ ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL);
+ for (int i = 0; i < TXG_SIZE; i++)
+ ASSERT3P(zilog->zl_itxg[i].itxg_itxs, ==, NULL);
+ return;
+ }
+
+ /*
+ * If the ZIL is suspended, we don't want to dirty it by calling
+ * zil_commit_itx_assign() below, nor can we write out
+ * lwbs like would be done in zil_commit_write(). Thus, we
+ * simply rely on txg_wait_synced() to maintain the necessary
+ * semantics, and avoid calling those functions altogether.
+ */
+ if (zilog->zl_suspend > 0) {
+ txg_wait_synced(zilog->zl_dmu_pool, 0);
+ return;
+ }
+
ZIL_STAT_BUMP(zil_commit_count);
- /* move the async itxs for the foid to the sync queues */
+ /*
+ * Move the "async" itxs for the specified foid to the "sync"
+ * queues, such that they will be later committed (or skipped)
+ * to an lwb when zil_process_commit_list() is called.
+ *
+ * Since these "async" itxs must be committed prior to this
+ * call to zil_commit returning, we must perform this operation
+ * before we call zil_commit_itx_assign().
+ */
zil_async_to_sync(zilog, foid);
- mutex_enter(&zilog->zl_lock);
- mybatch = zilog->zl_next_batch;
- while (zilog->zl_writer) {
- cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
- if (mybatch <= zilog->zl_com_batch) {
- mutex_exit(&zilog->zl_lock);
- return;
- }
- }
-
- zilog->zl_next_batch++;
- zilog->zl_writer = B_TRUE;
- ZIL_STAT_BUMP(zil_commit_writer_count);
- zil_commit_writer(zilog);
- zilog->zl_com_batch = mybatch;
- zilog->zl_writer = B_FALSE;
+ /*
+ * We allocate a new "waiter" structure which will initially be
+ * linked to the commit itx using the itx's "itx_private" field.
+ * Since the commit itx doesn't represent any on-disk state,
+ * when it's committed to an lwb, rather than copying the its
+ * lr_t into the lwb's buffer, the commit itx's "waiter" will be
+ * added to the lwb's list of waiters. Then, when the lwb is
+ * committed to stable storage, each waiter in the lwb's list of
+ * waiters will be marked "done", and signalled.
+ *
+ * We must create the waiter and assign the commit itx prior to
+ * calling zil_commit_writer(), or else our specific commit itx
+ * is not guaranteed to be committed to an lwb prior to calling
+ * zil_commit_waiter().
+ */
+ zil_commit_waiter_t *zcw = zil_alloc_commit_waiter();
+ zil_commit_itx_assign(zilog, zcw);
- /* wake up one thread to become the next writer */
- cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
+ zil_commit_writer(zilog, zcw);
+ zil_commit_waiter(zilog, zcw);
- /* wake up all threads waiting for this batch to be committed */
- cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
+ if (zcw->zcw_zio_error != 0) {
+ /*
+ * If there was an error writing out the ZIL blocks that
+ * this thread is waiting on, then we fallback to
+ * relying on spa_sync() to write out the data this
+ * thread is waiting on. Obviously this has performance
+ * implications, but the expectation is for this to be
+ * an exceptional case, and shouldn't occur often.
+ */
+ DTRACE_PROBE2(zil__commit__io__error,
+ zilog_t *, zilog, zil_commit_waiter_t *, zcw);
+ txg_wait_synced(zilog->zl_dmu_pool, 0);
+ }
- mutex_exit(&zilog->zl_lock);
+ zil_free_commit_waiter(zcw);
}
/*
@@ -1799,12 +2790,9 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
zh->zh_log = lwb->lwb_blk;
if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
break;
-
- ASSERT(lwb->lwb_zio == NULL);
-
list_remove(&zilog->zl_lwb_list, lwb);
- zio_free_zil(spa, txg, &lwb->lwb_blk);
- kmem_cache_free(zil_lwb_cache, lwb);
+ zio_free(spa, txg, &lwb->lwb_blk);
+ zil_free_lwb(zilog, lwb);
/*
* If we don't have anything left in the lwb list then
@@ -1822,7 +2810,7 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
* unused, long-lived LWBs.
*/
for (; lwb != NULL; lwb = list_next(&zilog->zl_lwb_list, lwb)) {
- if (lwb->lwb_fastwrite && !lwb->lwb_zio) {
+ if (lwb->lwb_fastwrite && !lwb->lwb_write_zio) {
metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk);
lwb->lwb_fastwrite = 0;
}
@@ -1831,11 +2819,39 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
mutex_exit(&zilog->zl_lock);
}
+/* ARGSUSED */
+static int
+zil_lwb_cons(void *vbuf, void *unused, int kmflag)
+{
+ lwb_t *lwb = vbuf;
+ list_create(&lwb->lwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node));
+ list_create(&lwb->lwb_waiters, sizeof (zil_commit_waiter_t),
+ offsetof(zil_commit_waiter_t, zcw_node));
+ avl_create(&lwb->lwb_vdev_tree, zil_lwb_vdev_compare,
+ sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
+ mutex_init(&lwb->lwb_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
+ return (0);
+}
+
+/* ARGSUSED */
+static void
+zil_lwb_dest(void *vbuf, void *unused)
+{
+ lwb_t *lwb = vbuf;
+ mutex_destroy(&lwb->lwb_vdev_lock);
+ avl_destroy(&lwb->lwb_vdev_tree);
+ list_destroy(&lwb->lwb_waiters);
+ list_destroy(&lwb->lwb_itxs);
+}
+
void
zil_init(void)
{
zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
- sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
+ sizeof (lwb_t), 0, zil_lwb_cons, zil_lwb_dest, NULL, NULL, NULL, 0);
+
+ zil_zcw_cache = kmem_cache_create("zil_zcw_cache",
+ sizeof (zil_commit_waiter_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
zil_ksp = kstat_create("zfs", 0, "zil", "misc",
KSTAT_TYPE_NAMED, sizeof (zil_stats) / sizeof (kstat_named_t),
@@ -1850,6 +2866,7 @@ zil_init(void)
void
zil_fini(void)
{
+ kmem_cache_destroy(zil_zcw_cache);
kmem_cache_destroy(zil_lwb_cache);
if (zil_ksp != NULL) {
@@ -1884,9 +2901,12 @@ zil_alloc(objset_t *os, zil_header_t *zh_phys)
zilog->zl_destroy_txg = TXG_INITIAL - 1;
zilog->zl_logbias = dmu_objset_logbias(os);
zilog->zl_sync = dmu_objset_syncprop(os);
- zilog->zl_next_batch = 1;
+ zilog->zl_dirty_max_txg = 0;
+ zilog->zl_last_lwb_opened = NULL;
+ 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);
for (int i = 0; i < TXG_SIZE; i++) {
mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
@@ -1899,15 +2919,7 @@ zil_alloc(objset_t *os, zil_header_t *zh_phys)
list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
offsetof(itx_t, itx_node));
- mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
-
- avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
- sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
-
- cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
- cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
- cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
return (zilog);
}
@@ -1925,9 +2937,6 @@ zil_free(zilog_t *zilog)
ASSERT(list_is_empty(&zilog->zl_lwb_list));
list_destroy(&zilog->zl_lwb_list);
- avl_destroy(&zilog->zl_vdev_tree);
- mutex_destroy(&zilog->zl_vdev_lock);
-
ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
list_destroy(&zilog->zl_itx_commit_list);
@@ -1944,12 +2953,10 @@ zil_free(zilog_t *zilog)
mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
}
+ mutex_destroy(&zilog->zl_writer_lock);
mutex_destroy(&zilog->zl_lock);
- cv_destroy(&zilog->zl_cv_writer);
cv_destroy(&zilog->zl_cv_suspend);
- cv_destroy(&zilog->zl_cv_batch[0]);
- cv_destroy(&zilog->zl_cv_batch[1]);
kmem_free(zilog, sizeof (zilog_t));
}
@@ -1962,7 +2969,8 @@ zil_open(objset_t *os, zil_get_data_t *get_data)
{
zilog_t *zilog = dmu_objset_zil(os);
- ASSERT(zilog->zl_get_data == NULL);
+ ASSERT3P(zilog->zl_get_data, ==, NULL);
+ ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL);
ASSERT(list_is_empty(&zilog->zl_lwb_list));
zilog->zl_get_data = get_data;
@@ -1977,22 +2985,30 @@ void
zil_close(zilog_t *zilog)
{
lwb_t *lwb;
- uint64_t txg = 0;
+ uint64_t txg;
- zil_commit(zilog, 0); /* commit all itx */
+ if (!dmu_objset_is_snapshot(zilog->zl_os)) {
+ zil_commit(zilog, 0);
+ } else {
+ ASSERT3P(list_tail(&zilog->zl_lwb_list), ==, NULL);
+ ASSERT0(zilog->zl_dirty_max_txg);
+ ASSERT3B(zilog_is_dirty(zilog), ==, B_FALSE);
+ }
- /*
- * The lwb_max_txg for the stubby lwb will reflect the last activity
- * for the zil. After a txg_wait_synced() on the txg we know all the
- * callbacks have occurred that may clean the zil. Only then can we
- * destroy the zl_clean_taskq.
- */
mutex_enter(&zilog->zl_lock);
lwb = list_tail(&zilog->zl_lwb_list);
- if (lwb != NULL)
- txg = lwb->lwb_max_txg;
+ if (lwb == NULL)
+ txg = zilog->zl_dirty_max_txg;
+ else
+ txg = MAX(zilog->zl_dirty_max_txg, lwb->lwb_max_txg);
mutex_exit(&zilog->zl_lock);
- if (txg)
+
+ /*
+ * We need to use txg_wait_synced() to wait long enough for the
+ * ZIL to be clean, and to wait for all pending lwbs to be
+ * written out.
+ */
+ if (txg != 0)
txg_wait_synced(zilog->zl_dmu_pool, txg);
if (zilog_is_dirty(zilog))
@@ -2003,18 +3019,20 @@ zil_close(zilog_t *zilog)
zilog->zl_get_data = NULL;
/*
- * We should have only one LWB left on the list; remove it now.
+ * We should have only one lwb left on the list; remove it now.
*/
mutex_enter(&zilog->zl_lock);
lwb = list_head(&zilog->zl_lwb_list);
if (lwb != NULL) {
- ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
- ASSERT(lwb->lwb_zio == NULL);
+ ASSERT3P(lwb, ==, list_tail(&zilog->zl_lwb_list));
+ ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED);
+
if (lwb->lwb_fastwrite)
metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk);
+
list_remove(&zilog->zl_lwb_list, lwb);
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
- kmem_cache_free(zil_lwb_cache, lwb);
+ zil_free_lwb(zilog, lwb);
}
mutex_exit(&zilog->zl_lock);
}
@@ -2376,7 +3394,7 @@ EXPORT_SYMBOL(zil_sync);
EXPORT_SYMBOL(zil_clean);
EXPORT_SYMBOL(zil_suspend);
EXPORT_SYMBOL(zil_resume);
-EXPORT_SYMBOL(zil_add_block);
+EXPORT_SYMBOL(zil_lwb_add_block);
EXPORT_SYMBOL(zil_bp_tree_add);
EXPORT_SYMBOL(zil_set_sync);
EXPORT_SYMBOL(zil_set_logbias);
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 311f79e23..92e5a8dd8 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -568,7 +568,7 @@ zio_add_child(zio_t *pio, zio_t *cio)
* Vdev I/Os can only have vdev children.
* The following ASSERT captures all of these constraints.
*/
- ASSERT(cio->io_child_type <= pio->io_child_type);
+ ASSERT3S(cio->io_child_type, <=, pio->io_child_type);
zl->zl_parent = pio;
zl->zl_child = cio;
@@ -1281,9 +1281,9 @@ zio_flush(zio_t *zio, vdev_t *vd)
void
zio_shrink(zio_t *zio, uint64_t size)
{
- ASSERT(zio->io_executor == NULL);
- ASSERT(zio->io_orig_size == zio->io_size);
- ASSERT(size <= zio->io_size);
+ ASSERT3P(zio->io_executor, ==, NULL);
+ ASSERT3U(zio->io_orig_size, ==, zio->io_size);
+ ASSERT3U(size, <=, zio->io_size);
/*
* We don't shrink for raidz because of problems with the
@@ -1877,8 +1877,8 @@ zio_wait(zio_t *zio)
{
int error;
- ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
- ASSERT(zio->io_executor == NULL);
+ ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN);
+ ASSERT3P(zio->io_executor, ==, NULL);
zio->io_waiter = curthread;
ASSERT0(zio->io_queued_timestamp);
@@ -1900,7 +1900,7 @@ zio_wait(zio_t *zio)
void
zio_nowait(zio_t *zio)
{
- ASSERT(zio->io_executor == NULL);
+ ASSERT3P(zio->io_executor, ==, NULL);
if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
zio_unique_parent(zio) == NULL) {
@@ -1926,7 +1926,7 @@ zio_nowait(zio_t *zio)
/*
* ==========================================================================
- * Reexecute or suspend/resume failed I/O
+ * Reexecute, cancel, or suspend/resume failed I/O
* ==========================================================================
*/
@@ -1984,6 +1984,20 @@ zio_reexecute(zio_t *pio)
}
void
+zio_cancel(zio_t *zio)
+{
+ /*
+ * Disallow cancellation of a zio that's already been issued.
+ */
+ VERIFY3P(zio->io_executor, ==, NULL);
+
+ zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
+ zio->io_done = NULL;
+
+ zio_nowait(zio);
+}
+
+void
zio_suspend(spa_t *spa, zio_t *zio)
{
if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
@@ -3276,6 +3290,9 @@ zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp,
zio_crypt_encode_params_bp(new_bp, salt, iv);
}
+ } else {
+ zfs_dbgmsg("%s: zil block allocation failure: "
+ "size %llu, error %d", spa_name(spa), size, error);
}
return (error);
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index 5cd190c09..6ea822467 100644
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -1052,7 +1052,7 @@ zvol_get_done(zgd_t *zgd, int error)
zfs_range_unlock(zgd->zgd_rl);
if (error == 0 && zgd->zgd_bp)
- zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
+ zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
kmem_free(zgd, sizeof (zgd_t));
}
@@ -1061,7 +1061,7 @@ zvol_get_done(zgd_t *zgd, int error)
* Get data to generate a TX_WRITE intent log record.
*/
static int
-zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
+zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
{
zvol_state_t *zv = arg;
uint64_t offset = lr->lr_offset;
@@ -1070,11 +1070,12 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
zgd_t *zgd;
int error;
- ASSERT(zio != NULL);
- ASSERT(size != 0);
+ ASSERT3P(lwb, !=, NULL);
+ ASSERT3P(zio, !=, NULL);
+ ASSERT3U(size, !=, 0);
zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
- zgd->zgd_zilog = zv->zv_zilog;
+ zgd->zgd_lwb = lwb;
/*
* Write records come in two flavors: immediate and indirect.
diff --git a/scripts/zloop.sh b/scripts/zloop.sh
index a45c45024..afcd87f36 100755
--- a/scripts/zloop.sh
+++ b/scripts/zloop.sh
@@ -254,7 +254,7 @@ while [[ $timeout -eq 0 ]] || [[ $curtime -le $((starttime + timeout)) ]]; do
$cmd >>ztest.out 2>&1
ztrc=$?
egrep '===|WARNING' ztest.out >>ztest.history
- $ZDB -U "$workdir/zpool.cache" -DD ztest >>ztest.ddt
+ $ZDB -U "$workdir/zpool.cache" -DD ztest >>ztest.ddt 2>&1
store_core
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 14:10:58 +0000