--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Tom Caputi <tcaputi@datto.com>
+Date: Tue, 10 Apr 2018 14:15:05 -0400
+Subject: [PATCH] Fix race in dnode_check_slots_free()
+
+Currently, dnode_check_slots_free() works by checking dn->dn_type
+in the dnode to determine if the dnode is reclaimable. However,
+there is a small window of time between dnode_free_sync() in the
+first call to dsl_dataset_sync() and when the useraccounting code
+is run when the type is set DMU_OT_NONE, but the dnode is not yet
+evictable, leading to crashes. This patch adds the ability for
+dnodes to track which txg they were last dirtied in and adds a
+check for this before performing the reclaim.
+
+This patch also corrects several instances when dn_dirty_link was
+treated as a list_node_t when it is technically a multilist_node_t.
+
+Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
+Signed-off-by: Tom Caputi <tcaputi@datto.com>
+Requires-spl: spl-0.7-release
+Issue #7147
+Issue #7388
+Issue #7997
+
+(cherry-picked from behlendorf/issue-7997 4764f6f3be90be073d2700653dff286371e52583)
+Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
+---
+ include/sys/dmu_impl.h | 1 +
+ include/sys/dnode.h | 4 ++++
+ module/zfs/dbuf.c | 3 +++
+ module/zfs/dmu.c | 2 +-
+ module/zfs/dmu_objset.c | 15 +++++++++++++++
+ module/zfs/dnode.c | 29 +++++++++++++++++++----------
+ 6 files changed, 43 insertions(+), 11 deletions(-)
+
+diff --git a/include/sys/dmu_impl.h b/include/sys/dmu_impl.h
+index 65e417e3..03a63077 100644
+--- a/include/sys/dmu_impl.h
++++ b/include/sys/dmu_impl.h
+@@ -161,6 +161,7 @@ extern "C" {
+ * dn_allocated_txg
+ * dn_free_txg
+ * dn_assigned_txg
++ * dn_dirty_txg
+ * dd_assigned_tx
+ * dn_notxholds
+ * dn_dirtyctx
+diff --git a/include/sys/dnode.h b/include/sys/dnode.h
+index ea7defe1..2dd087b3 100644
+--- a/include/sys/dnode.h
++++ b/include/sys/dnode.h
+@@ -260,6 +260,7 @@ struct dnode {
+ uint64_t dn_allocated_txg;
+ uint64_t dn_free_txg;
+ uint64_t dn_assigned_txg;
++ uint64_t dn_dirty_txg; /* txg dnode was last dirtied */
+ kcondvar_t dn_notxholds;
+ enum dnode_dirtycontext dn_dirtyctx;
+ uint8_t *dn_dirtyctx_firstset; /* dbg: contents meaningless */
+@@ -362,6 +363,9 @@ void dnode_evict_dbufs(dnode_t *dn);
+ void dnode_evict_bonus(dnode_t *dn);
+ void dnode_free_interior_slots(dnode_t *dn);
+
++#define DNODE_IS_DIRTY(_dn) \
++ ((_dn)->dn_dirty_txg >= spa_syncing_txg((_dn)->dn_objset->os_spa))
++
+ #define DNODE_IS_CACHEABLE(_dn) \
+ ((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL || \
+ (DMU_OT_IS_METADATA((_dn)->dn_type) && \
+diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
+index 4ee121f5..6edb39d6 100644
+--- a/module/zfs/dbuf.c
++++ b/module/zfs/dbuf.c
+@@ -1606,6 +1606,9 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
+ FTAG);
+ }
+ }
++
++ if (tx->tx_txg > dn->dn_dirty_txg)
++ dn->dn_dirty_txg = tx->tx_txg;
+ mutex_exit(&dn->dn_mtx);
+
+ if (db->db_blkid == DMU_SPILL_BLKID)
+diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
+index 6f09aa2f..a09ac4f9 100644
+--- a/module/zfs/dmu.c
++++ b/module/zfs/dmu.c
+@@ -2044,7 +2044,7 @@ dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
+ * Check if dnode is dirty
+ */
+ for (i = 0; i < TXG_SIZE; i++) {
+- if (list_link_active(&dn->dn_dirty_link[i])) {
++ if (multilist_link_active(&dn->dn_dirty_link[i])) {
+ clean = B_FALSE;
+ break;
+ }
+diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c
+index 449ebedf..0bed2d3e 100644
+--- a/module/zfs/dmu_objset.c
++++ b/module/zfs/dmu_objset.c
+@@ -1213,10 +1213,23 @@ dmu_objset_sync_dnodes(multilist_sublist_t *list, dmu_tx_t *tx)
+ ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS);
+ multilist_sublist_remove(list, dn);
+
++ /*
++ * If we are not doing useraccounting (os_synced_dnodes == NULL)
++ * we are done with this dnode for this txg. Unset dn_dirty_txg
++ * if later txgs aren't dirtying it so that future holders do
++ * not get a stale value. Otherwise, we will do this in
++ * userquota_updates_task() when processing has completely
++ * finished for this txg.
++ */
+ multilist_t *newlist = dn->dn_objset->os_synced_dnodes;
+ if (newlist != NULL) {
+ (void) dnode_add_ref(dn, newlist);
+ multilist_insert(newlist, dn);
++ } else {
++ mutex_enter(&dn->dn_mtx);
++ if (dn->dn_dirty_txg == tx->tx_txg)
++ dn->dn_dirty_txg = 0;
++ mutex_exit(&dn->dn_mtx);
+ }
+
+ dnode_sync(dn, tx);
+@@ -1621,6 +1634,8 @@ userquota_updates_task(void *arg)
+ dn->dn_id_flags |= DN_ID_CHKED_BONUS;
+ }
+ dn->dn_id_flags &= ~(DN_ID_NEW_EXIST);
++ if (dn->dn_dirty_txg == spa_syncing_txg(os->os_spa))
++ dn->dn_dirty_txg = 0;
+ mutex_exit(&dn->dn_mtx);
+
+ multilist_sublist_remove(list, dn);
+diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
+index d465b545..4a169c49 100644
+--- a/module/zfs/dnode.c
++++ b/module/zfs/dnode.c
+@@ -137,7 +137,7 @@ dnode_cons(void *arg, void *unused, int kmflag)
+ bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
+
+ for (i = 0; i < TXG_SIZE; i++) {
+- list_link_init(&dn->dn_dirty_link[i]);
++ multilist_link_init(&dn->dn_dirty_link[i]);
+ dn->dn_free_ranges[i] = NULL;
+ list_create(&dn->dn_dirty_records[i],
+ sizeof (dbuf_dirty_record_t),
+@@ -147,6 +147,7 @@ dnode_cons(void *arg, void *unused, int kmflag)
+ dn->dn_allocated_txg = 0;
+ dn->dn_free_txg = 0;
+ dn->dn_assigned_txg = 0;
++ dn->dn_dirty_txg = 0;
+ dn->dn_dirtyctx = 0;
+ dn->dn_dirtyctx_firstset = NULL;
+ dn->dn_bonus = NULL;
+@@ -184,7 +185,7 @@ dnode_dest(void *arg, void *unused)
+ ASSERT(!list_link_active(&dn->dn_link));
+
+ for (i = 0; i < TXG_SIZE; i++) {
+- ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
++ ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
+ ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
+ list_destroy(&dn->dn_dirty_records[i]);
+ ASSERT0(dn->dn_next_nblkptr[i]);
+@@ -199,6 +200,7 @@ dnode_dest(void *arg, void *unused)
+ ASSERT0(dn->dn_allocated_txg);
+ ASSERT0(dn->dn_free_txg);
+ ASSERT0(dn->dn_assigned_txg);
++ ASSERT0(dn->dn_dirty_txg);
+ ASSERT0(dn->dn_dirtyctx);
+ ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
+ ASSERT3P(dn->dn_bonus, ==, NULL);
+@@ -523,6 +525,7 @@ dnode_destroy(dnode_t *dn)
+ dn->dn_allocated_txg = 0;
+ dn->dn_free_txg = 0;
+ dn->dn_assigned_txg = 0;
++ dn->dn_dirty_txg = 0;
+
+ dn->dn_dirtyctx = 0;
+ if (dn->dn_dirtyctx_firstset != NULL) {
+@@ -592,6 +595,7 @@ dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
+ ASSERT0(dn->dn_maxblkid);
+ ASSERT0(dn->dn_allocated_txg);
+ ASSERT0(dn->dn_assigned_txg);
++ ASSERT0(dn->dn_dirty_txg);
+ ASSERT(refcount_is_zero(&dn->dn_tx_holds));
+ ASSERT3U(refcount_count(&dn->dn_holds), <=, 1);
+ ASSERT(avl_is_empty(&dn->dn_dbufs));
+@@ -604,7 +608,7 @@ dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
+ ASSERT0(dn->dn_next_bonustype[i]);
+ ASSERT0(dn->dn_rm_spillblk[i]);
+ ASSERT0(dn->dn_next_blksz[i]);
+- ASSERT(!list_link_active(&dn->dn_dirty_link[i]));
++ ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
+ ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
+ ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
+ }
+@@ -779,6 +783,7 @@ dnode_move_impl(dnode_t *odn, dnode_t *ndn)
+ ndn->dn_allocated_txg = odn->dn_allocated_txg;
+ ndn->dn_free_txg = odn->dn_free_txg;
+ ndn->dn_assigned_txg = odn->dn_assigned_txg;
++ ndn->dn_dirty_txg = odn->dn_dirty_txg;
+ ndn->dn_dirtyctx = odn->dn_dirtyctx;
+ ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
+ ASSERT(refcount_count(&odn->dn_tx_holds) == 0);
+@@ -845,6 +850,7 @@ dnode_move_impl(dnode_t *odn, dnode_t *ndn)
+ odn->dn_allocated_txg = 0;
+ odn->dn_free_txg = 0;
+ odn->dn_assigned_txg = 0;
++ odn->dn_dirty_txg = 0;
+ odn->dn_dirtyctx = 0;
+ odn->dn_dirtyctx_firstset = NULL;
+ odn->dn_have_spill = B_FALSE;
+@@ -1069,6 +1075,10 @@ dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
+ {
+ ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
+
++ /*
++ * If all dnode slots are either already free or
++ * evictable return B_TRUE.
++ */
+ for (int i = idx; i < idx + slots; i++) {
+ dnode_handle_t *dnh = &children->dnc_children[i];
+ dnode_t *dn = dnh->dnh_dnode;
+@@ -1077,18 +1087,17 @@ dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
+ continue;
+ } else if (DN_SLOT_IS_PTR(dn)) {
+ mutex_enter(&dn->dn_mtx);
+- dmu_object_type_t type = dn->dn_type;
++ boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
++ !DNODE_IS_DIRTY(dn));
+ mutex_exit(&dn->dn_mtx);
+
+- if (type != DMU_OT_NONE)
++ if (!can_free)
+ return (B_FALSE);
+-
+- continue;
++ else
++ continue;
+ } else {
+ return (B_FALSE);
+ }
+-
+- return (B_FALSE);
+ }
+
+ return (B_TRUE);
+@@ -1594,7 +1603,7 @@ dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
+ /*
+ * If we are already marked dirty, we're done.
+ */
+- if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
++ if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
+ multilist_sublist_unlock(mls);
+ return;
+ }
--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Matthew Ahrens <mahrens@delphix.com>
+Date: Thu, 2 Aug 2018 15:51:45 -0700
+Subject: [PATCH] Reduce taskq and context-switch cost of zio pipe
+
+When doing a read from disk, ZFS creates 3 ZIO's: a zio_null(), the
+logical zio_read(), and then a physical zio. Currently, each of these
+results in a separate taskq_dispatch(zio_execute).
+
+On high-read-iops workloads, this causes a significant performance
+impact. By processing all 3 ZIO's in a single taskq entry, we reduce the
+overhead on taskq locking and context switching. We accomplish this by
+allowing zio_done() to return a "next zio to execute" to zio_execute().
+
+This results in a ~12% performance increase for random reads, from
+96,000 iops to 108,000 iops (with recordsize=8k, on SSD's).
+
+Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
+Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
+Reviewed by: George Wilson <george.wilson@delphix.com>
+Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
+External-issue: DLPX-59292
+Requires-spl: spl-0.7-release
+Closes #7736
+
+(cherry-picked from behlendorf/issue-7736 496657ab3bcfeb638b1786e1759980ccfcacb08e)
+Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
+---
+ include/sys/zio.h | 4 +-
+ module/zfs/zio.c | 250 +++++++++++++++++++++++++++++-------------------------
+ 2 files changed, 137 insertions(+), 117 deletions(-)
+
+diff --git a/include/sys/zio.h b/include/sys/zio.h
+index 4b0eecc2..3618912c 100644
+--- a/include/sys/zio.h
++++ b/include/sys/zio.h
+@@ -237,7 +237,7 @@ enum zio_child {
+ #define ZIO_CHILD_DDT_BIT ZIO_CHILD_BIT(ZIO_CHILD_DDT)
+ #define ZIO_CHILD_LOGICAL_BIT ZIO_CHILD_BIT(ZIO_CHILD_LOGICAL)
+ #define ZIO_CHILD_ALL_BITS \
+- (ZIO_CHILD_VDEV_BIT | ZIO_CHILD_GANG_BIT | \
++ (ZIO_CHILD_VDEV_BIT | ZIO_CHILD_GANG_BIT | \
+ ZIO_CHILD_DDT_BIT | ZIO_CHILD_LOGICAL_BIT)
+
+ enum zio_wait_type {
+@@ -375,7 +375,7 @@ typedef struct zio_transform {
+ struct zio_transform *zt_next;
+ } zio_transform_t;
+
+-typedef int zio_pipe_stage_t(zio_t *zio);
++typedef zio_t *zio_pipe_stage_t(zio_t *zio);
+
+ /*
+ * The io_reexecute flags are distinct from io_flags because the child must
+diff --git a/module/zfs/zio.c b/module/zfs/zio.c
+index 9a465e1b..b08b4747 100644
+--- a/module/zfs/zio.c
++++ b/module/zfs/zio.c
+@@ -75,9 +75,6 @@ uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
+
+ int zio_delay_max = ZIO_DELAY_MAX;
+
+-#define ZIO_PIPELINE_CONTINUE 0x100
+-#define ZIO_PIPELINE_STOP 0x101
+-
+ #define BP_SPANB(indblkshift, level) \
+ (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT)))
+ #define COMPARE_META_LEVEL 0x80000000ul
+@@ -516,7 +513,8 @@ zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
+
+ __attribute__((always_inline))
+ static inline void
+-zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
++zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait,
++ zio_t **next_to_executep)
+ {
+ uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
+ int *errorp = &pio->io_child_error[zio->io_child_type];
+@@ -535,13 +533,33 @@ zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
+ ZIO_TASKQ_INTERRUPT;
+ pio->io_stall = NULL;
+ mutex_exit(&pio->io_lock);
++
+ /*
+- * Dispatch the parent zio in its own taskq so that
+- * the child can continue to make progress. This also
+- * prevents overflowing the stack when we have deeply nested
+- * parent-child relationships.
++ * If we can tell the caller to execute this parent next, do
++ * so. Otherwise dispatch the parent zio as its own task.
++ *
++ * Having the caller execute the parent when possible reduces
++ * locking on the zio taskq's, reduces context switch
++ * overhead, and has no recursion penalty. Note that one
++ * read from disk typically causes at least 3 zio's: a
++ * zio_null(), the logical zio_read(), and then a physical
++ * zio. When the physical ZIO completes, we are able to call
++ * zio_done() on all 3 of these zio's from one invocation of
++ * zio_execute() by returning the parent back to
++ * zio_execute(). Since the parent isn't executed until this
++ * thread returns back to zio_execute(), the caller should do
++ * so promptly.
++ *
++ * In other cases, dispatching the parent prevents
++ * overflowing the stack when we have deeply nested
++ * parent-child relationships, as we do with the "mega zio"
++ * of writes for spa_sync(), and the chain of ZIL blocks.
+ */
+- zio_taskq_dispatch(pio, type, B_FALSE);
++ if (next_to_executep != NULL && *next_to_executep == NULL) {
++ *next_to_executep = pio;
++ } else {
++ zio_taskq_dispatch(pio, type, B_FALSE);
++ }
+ } else {
+ mutex_exit(&pio->io_lock);
+ }
+@@ -1187,7 +1205,7 @@ zio_shrink(zio_t *zio, uint64_t size)
+ * ==========================================================================
+ */
+
+-static int
++static zio_t *
+ zio_read_bp_init(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -1221,15 +1239,15 @@ zio_read_bp_init(zio_t *zio)
+ if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
+ zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_write_bp_init(zio_t *zio)
+ {
+
+ if (!IO_IS_ALLOCATING(zio))
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
+
+@@ -1244,7 +1262,7 @@ zio_write_bp_init(zio_t *zio)
+ zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
+
+ if (BP_IS_EMBEDDED(bp))
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ /*
+ * If we've been overridden and nopwrite is set then
+@@ -1255,13 +1273,13 @@ zio_write_bp_init(zio_t *zio)
+ ASSERT(!zp->zp_dedup);
+ ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum);
+ zio->io_flags |= ZIO_FLAG_NOPWRITE;
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ ASSERT(!zp->zp_nopwrite);
+
+ if (BP_IS_HOLE(bp) || !zp->zp_dedup)
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags &
+ ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify);
+@@ -1269,7 +1287,7 @@ zio_write_bp_init(zio_t *zio)
+ if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) {
+ BP_SET_DEDUP(bp, 1);
+ zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -1281,10 +1299,10 @@ zio_write_bp_init(zio_t *zio)
+ zio->io_pipeline = zio->io_orig_pipeline;
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_write_compress(zio_t *zio)
+ {
+ spa_t *spa = zio->io_spa;
+@@ -1303,11 +1321,11 @@ zio_write_compress(zio_t *zio)
+ */
+ if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT |
+ ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ if (!IO_IS_ALLOCATING(zio))
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ if (zio->io_children_ready != NULL) {
+ /*
+@@ -1366,7 +1384,7 @@ zio_write_compress(zio_t *zio)
+ zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
+ ASSERT(spa_feature_is_active(spa,
+ SPA_FEATURE_EMBEDDED_DATA));
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ } else {
+ /*
+ * Round up compressed size up to the ashift
+@@ -1459,10 +1477,10 @@ zio_write_compress(zio_t *zio)
+ zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
+ }
+ }
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_free_bp_init(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -1472,7 +1490,7 @@ zio_free_bp_init(zio_t *zio)
+ zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -1541,12 +1559,12 @@ zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
+ return (B_FALSE);
+ }
+
+-static int
++static zio_t *
+ zio_issue_async(zio_t *zio)
+ {
+ zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
+
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ void
+@@ -1687,14 +1705,13 @@ __attribute__((always_inline))
+ static inline void
+ __zio_execute(zio_t *zio)
+ {
+- zio->io_executor = curthread;
+-
+ ASSERT3U(zio->io_queued_timestamp, >, 0);
+
+ while (zio->io_stage < ZIO_STAGE_DONE) {
+ enum zio_stage pipeline = zio->io_pipeline;
+ enum zio_stage stage = zio->io_stage;
+- int rv;
++
++ zio->io_executor = curthread;
+
+ ASSERT(!MUTEX_HELD(&zio->io_lock));
+ ASSERT(ISP2(stage));
+@@ -1736,12 +1753,16 @@ __zio_execute(zio_t *zio)
+
+ zio->io_stage = stage;
+ zio->io_pipeline_trace |= zio->io_stage;
+- rv = zio_pipeline[highbit64(stage) - 1](zio);
+
+- if (rv == ZIO_PIPELINE_STOP)
+- return;
++ /*
++ * The zio pipeline stage returns the next zio to execute
++ * (typically the same as this one), or NULL if we should
++ * stop.
++ */
++ zio = zio_pipeline[highbit64(stage) - 1](zio);
+
+- ASSERT(rv == ZIO_PIPELINE_CONTINUE);
++ if (zio == NULL)
++ return;
+ }
+ }
+
+@@ -2215,7 +2236,7 @@ zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data,
+ zio_nowait(zio);
+ }
+
+-static int
++static zio_t *
+ zio_gang_assemble(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -2227,16 +2248,16 @@ zio_gang_assemble(zio_t *zio)
+
+ zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_gang_issue(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+
+ if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
+@@ -2250,7 +2271,7 @@ zio_gang_issue(zio_t *zio)
+
+ zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ static void
+@@ -2290,7 +2311,7 @@ zio_write_gang_done(zio_t *zio)
+ abd_put(zio->io_abd);
+ }
+
+-static int
++static zio_t *
+ zio_write_gang_block(zio_t *pio)
+ {
+ spa_t *spa = pio->io_spa;
+@@ -2349,7 +2370,7 @@ zio_write_gang_block(zio_t *pio)
+ }
+
+ pio->io_error = error;
+- return (ZIO_PIPELINE_CONTINUE);
++ return (pio);
+ }
+
+ if (pio == gio) {
+@@ -2423,7 +2444,7 @@ zio_write_gang_block(zio_t *pio)
+
+ zio_nowait(zio);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (pio);
+ }
+
+ /*
+@@ -2444,7 +2465,7 @@ zio_write_gang_block(zio_t *pio)
+ * used for nopwrite, assuming that the salt and the checksums
+ * themselves remain secret.
+ */
+-static int
++static zio_t *
+ zio_nop_write(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -2471,7 +2492,7 @@ zio_nop_write(zio_t *zio)
+ BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
+ BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
+ zp->zp_copies != BP_GET_NDVAS(bp_orig))
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ /*
+ * If the checksums match then reset the pipeline so that we
+@@ -2491,7 +2512,7 @@ zio_nop_write(zio_t *zio)
+ zio->io_flags |= ZIO_FLAG_NOPWRITE;
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -2519,7 +2540,7 @@ zio_ddt_child_read_done(zio_t *zio)
+ mutex_exit(&pio->io_lock);
+ }
+
+-static int
++static zio_t *
+ zio_ddt_read_start(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -2540,7 +2561,7 @@ zio_ddt_read_start(zio_t *zio)
+ zio->io_vsd = dde;
+
+ if (ddp_self == NULL)
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ for (p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
+ if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
+@@ -2553,23 +2574,23 @@ zio_ddt_read_start(zio_t *zio)
+ zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) |
+ ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark));
+ }
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ zio_nowait(zio_read(zio, zio->io_spa, bp,
+ zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority,
+ ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_ddt_read_done(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+
+ if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ ASSERT(BP_GET_DEDUP(bp));
+@@ -2581,12 +2602,12 @@ zio_ddt_read_done(zio_t *zio)
+ ddt_entry_t *dde = zio->io_vsd;
+ if (ddt == NULL) {
+ ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+ if (dde == NULL) {
+ zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
+ zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+ if (dde->dde_repair_abd != NULL) {
+ abd_copy(zio->io_abd, dde->dde_repair_abd,
+@@ -2599,7 +2620,7 @@ zio_ddt_read_done(zio_t *zio)
+
+ ASSERT(zio->io_vsd == NULL);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ static boolean_t
+@@ -2780,7 +2801,7 @@ zio_ddt_ditto_write_done(zio_t *zio)
+ ddt_exit(ddt);
+ }
+
+-static int
++static zio_t *
+ zio_ddt_write(zio_t *zio)
+ {
+ spa_t *spa = zio->io_spa;
+@@ -2822,7 +2843,7 @@ zio_ddt_write(zio_t *zio)
+ }
+ zio->io_pipeline = ZIO_WRITE_PIPELINE;
+ ddt_exit(ddt);
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp);
+@@ -2848,7 +2869,7 @@ zio_ddt_write(zio_t *zio)
+ zio->io_bp_override = NULL;
+ BP_ZERO(bp);
+ ddt_exit(ddt);
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ dio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
+@@ -2890,12 +2911,12 @@ zio_ddt_write(zio_t *zio)
+ if (dio)
+ zio_nowait(dio);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ ddt_entry_t *freedde; /* for debugging */
+
+-static int
++static zio_t *
+ zio_ddt_free(zio_t *zio)
+ {
+ spa_t *spa = zio->io_spa;
+@@ -2916,7 +2937,7 @@ zio_ddt_free(zio_t *zio)
+ }
+ ddt_exit(ddt);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -2953,7 +2974,7 @@ zio_io_to_allocate(spa_t *spa)
+ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_dva_throttle(zio_t *zio)
+ {
+ spa_t *spa = zio->io_spa;
+@@ -2963,7 +2984,7 @@ zio_dva_throttle(zio_t *zio)
+ !spa_normal_class(zio->io_spa)->mc_alloc_throttle_enabled ||
+ zio->io_child_type == ZIO_CHILD_GANG ||
+ zio->io_flags & ZIO_FLAG_NODATA) {
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
+@@ -2979,22 +3000,7 @@ zio_dva_throttle(zio_t *zio)
+ nio = zio_io_to_allocate(zio->io_spa);
+ mutex_exit(&spa->spa_alloc_lock);
+
+- if (nio == zio)
+- return (ZIO_PIPELINE_CONTINUE);
+-
+- if (nio != NULL) {
+- ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE);
+- /*
+- * We are passing control to a new zio so make sure that
+- * it is processed by a different thread. We do this to
+- * avoid stack overflows that can occur when parents are
+- * throttled and children are making progress. We allow
+- * it to go to the head of the taskq since it's already
+- * been waiting.
+- */
+- zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE);
+- }
+- return (ZIO_PIPELINE_STOP);
++ return (nio);
+ }
+
+ void
+@@ -3013,7 +3019,7 @@ zio_allocate_dispatch(spa_t *spa)
+ zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE);
+ }
+
+-static int
++static zio_t *
+ zio_dva_allocate(zio_t *zio)
+ {
+ spa_t *spa = zio->io_spa;
+@@ -3054,18 +3060,18 @@ zio_dva_allocate(zio_t *zio)
+ zio->io_error = error;
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_dva_free(zio_t *zio)
+ {
+ metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_dva_claim(zio_t *zio)
+ {
+ int error;
+@@ -3074,7 +3080,7 @@ zio_dva_claim(zio_t *zio)
+ if (error)
+ zio->io_error = error;
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -3172,7 +3178,7 @@ zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp)
+ * force the underlying vdev layers to call either zio_execute() or
+ * zio_interrupt() to ensure that the pipeline continues with the correct I/O.
+ */
+-static int
++static zio_t *
+ zio_vdev_io_start(zio_t *zio)
+ {
+ vdev_t *vd = zio->io_vd;
+@@ -3192,7 +3198,7 @@ zio_vdev_io_start(zio_t *zio)
+ * The mirror_ops handle multiple DVAs in a single BP.
+ */
+ vdev_mirror_ops.vdev_op_io_start(zio);
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ ASSERT3P(zio->io_logical, !=, zio);
+@@ -3269,31 +3275,31 @@ zio_vdev_io_start(zio_t *zio)
+ !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
+ ASSERT(zio->io_type == ZIO_TYPE_WRITE);
+ zio_vdev_io_bypass(zio);
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ if (vd->vdev_ops->vdev_op_leaf &&
+ (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) {
+
+ if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio))
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ if ((zio = vdev_queue_io(zio)) == NULL)
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+
+ if (!vdev_accessible(vd, zio)) {
+ zio->io_error = SET_ERROR(ENXIO);
+ zio_interrupt(zio);
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+ zio->io_delay = gethrtime();
+ }
+
+ vd->vdev_ops->vdev_op_io_start(zio);
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+-static int
++static zio_t *
+ zio_vdev_io_done(zio_t *zio)
+ {
+ vdev_t *vd = zio->io_vd;
+@@ -3301,7 +3307,7 @@ zio_vdev_io_done(zio_t *zio)
+ boolean_t unexpected_error = B_FALSE;
+
+ if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
+@@ -3337,7 +3343,7 @@ zio_vdev_io_done(zio_t *zio)
+ if (unexpected_error)
+ VERIFY(vdev_probe(vd, zio) == NULL);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -3366,13 +3372,13 @@ zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored)
+ zcr->zcr_free = zio_abd_free;
+ }
+
+-static int
++static zio_t *
+ zio_vdev_io_assess(zio_t *zio)
+ {
+ vdev_t *vd = zio->io_vd;
+
+ if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
+@@ -3402,7 +3408,7 @@ zio_vdev_io_assess(zio_t *zio)
+ zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
+ zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
+ zio_requeue_io_start_cut_in_line);
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ /*
+@@ -3442,7 +3448,7 @@ zio_vdev_io_assess(zio_t *zio)
+ zio->io_physdone(zio->io_logical);
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ void
+@@ -3477,7 +3483,7 @@ zio_vdev_io_bypass(zio_t *zio)
+ * Generate and verify checksums
+ * ==========================================================================
+ */
+-static int
++static zio_t *
+ zio_checksum_generate(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -3491,7 +3497,7 @@ zio_checksum_generate(zio_t *zio)
+ checksum = zio->io_prop.zp_checksum;
+
+ if (checksum == ZIO_CHECKSUM_OFF)
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ ASSERT(checksum == ZIO_CHECKSUM_LABEL);
+ } else {
+@@ -3505,10 +3511,10 @@ zio_checksum_generate(zio_t *zio)
+
+ zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+-static int
++static zio_t *
+ zio_checksum_verify(zio_t *zio)
+ {
+ zio_bad_cksum_t info;
+@@ -3523,7 +3529,7 @@ zio_checksum_verify(zio_t *zio)
+ * We're either verifying a label checksum, or nothing at all.
+ */
+ if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+
+ ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL);
+ }
+@@ -3538,7 +3544,7 @@ zio_checksum_verify(zio_t *zio)
+ }
+ }
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -3581,7 +3587,7 @@ zio_worst_error(int e1, int e2)
+ * I/O completion
+ * ==========================================================================
+ */
+-static int
++static zio_t *
+ zio_ready(zio_t *zio)
+ {
+ blkptr_t *bp = zio->io_bp;
+@@ -3590,7 +3596,7 @@ zio_ready(zio_t *zio)
+
+ if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT,
+ ZIO_WAIT_READY)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ if (zio->io_ready) {
+@@ -3636,7 +3642,7 @@ zio_ready(zio_t *zio)
+ */
+ for (; pio != NULL; pio = pio_next) {
+ pio_next = zio_walk_parents(zio, &zl);
+- zio_notify_parent(pio, zio, ZIO_WAIT_READY);
++ zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL);
+ }
+
+ if (zio->io_flags & ZIO_FLAG_NODATA) {
+@@ -3652,7 +3658,7 @@ zio_ready(zio_t *zio)
+ zio->io_spa->spa_syncing_txg == zio->io_txg)
+ zio_handle_ignored_writes(zio);
+
+- return (ZIO_PIPELINE_CONTINUE);
++ return (zio);
+ }
+
+ /*
+@@ -3716,7 +3722,7 @@ zio_dva_throttle_done(zio_t *zio)
+ zio_allocate_dispatch(zio->io_spa);
+ }
+
+-static int
++static zio_t *
+ zio_done(zio_t *zio)
+ {
+ /*
+@@ -3733,7 +3739,7 @@ zio_done(zio_t *zio)
+ * wait for them and then repeat this pipeline stage.
+ */
+ if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) {
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ /*
+@@ -3957,7 +3963,12 @@ zio_done(zio_t *zio)
+ if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
+ (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
+ zio_remove_child(pio, zio, remove_zl);
+- zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
++ /*
++ * This is a rare code path, so we don't
++ * bother with "next_to_execute".
++ */
++ zio_notify_parent(pio, zio, ZIO_WAIT_DONE,
++ NULL);
+ }
+ }
+
+@@ -3969,7 +3980,11 @@ zio_done(zio_t *zio)
+ */
+ ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
+ zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
+- zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
++ /*
++ * This is a rare code path, so we don't bother with
++ * "next_to_execute".
++ */
++ zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL);
+ } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
+ /*
+ * We'd fail again if we reexecuted now, so suspend
+@@ -3987,7 +4002,7 @@ zio_done(zio_t *zio)
+ (task_func_t *)zio_reexecute, zio, 0,
+ &zio->io_tqent);
+ }
+- return (ZIO_PIPELINE_STOP);
++ return (NULL);
+ }
+
+ ASSERT(zio->io_child_count == 0);
+@@ -4023,12 +4038,17 @@ zio_done(zio_t *zio)
+ zio->io_state[ZIO_WAIT_DONE] = 1;
+ mutex_exit(&zio->io_lock);
+
++ /*
++ * We are done executing this zio. We may want to execute a parent
++ * next. See the comment in zio_notify_parent().
++ */
++ zio_t *next_to_execute = NULL;
+ zl = NULL;
+ for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) {
+ zio_link_t *remove_zl = zl;
+ pio_next = zio_walk_parents(zio, &zl);
+ zio_remove_child(pio, zio, remove_zl);
+- zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
++ zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute);
+ }
+
+ if (zio->io_waiter != NULL) {
+@@ -4040,7 +4060,7 @@ zio_done(zio_t *zio)
+ zio_destroy(zio);
+ }
+
+- return (ZIO_PIPELINE_STOP);
++ return (next_to_execute);
+ }
+
+ /*
projects / zfsonlinux.git / commitdiff