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Diffstat (limited to 'module/zfs/dmu_traverse.c')
-rw-r--r--module/zfs/dmu_traverse.c97
1 files changed, 83 insertions, 14 deletions
diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c
index 84407f15f..370a28aeb 100644
--- a/module/zfs/dmu_traverse.c
+++ b/module/zfs/dmu_traverse.c
@@ -63,6 +63,8 @@ typedef struct traverse_data {
static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *buf, uint64_t objset, uint64_t object);
+static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *,
+ arc_buf_t *buf, uint64_t objset, uint64_t object);
static int
traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
@@ -178,9 +180,34 @@ traverse_pause(traverse_data_t *td, const zbookmark_t *zb)
bcopy(zb, td->td_resume, sizeof (*td->td_resume));
}
+static void
+traverse_prefetch_metadata(traverse_data_t *td,
+ arc_buf_t *pbuf, const blkptr_t *bp, const zbookmark_t *zb)
+{
+ uint32_t flags = ARC_NOWAIT | ARC_PREFETCH;
+
+ if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
+ return;
+ /*
+ * If we are in the process of resuming, don't prefetch, because
+ * some children will not be needed (and in fact may have already
+ * been freed).
+ */
+ if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume))
+ return;
+ if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg)
+ return;
+ if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
+ return;
+
+ (void) arc_read(NULL, td->td_spa, bp,
+ pbuf, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
+ ZIO_FLAG_CANFAIL, &flags, zb);
+}
+
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
- arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
+ arc_buf_t *pbuf, const blkptr_t *bp, const zbookmark_t *zb)
{
zbookmark_t czb;
int err = 0, lasterr = 0;
@@ -243,14 +270,21 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
+ cbp = buf->b_data;
+
+ for (i = 0; i < epb; i++) {
+ SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
+ zb->zb_level - 1,
+ zb->zb_blkid * epb + i);
+ traverse_prefetch_metadata(td, buf, &cbp[i], &czb);
+ }
/* recursively visitbp() blocks below this */
- cbp = buf->b_data;
- for (i = 0; i < epb; i++, cbp++) {
+ for (i = 0; i < epb; i++) {
SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
zb->zb_level - 1,
zb->zb_blkid * epb + i);
- err = traverse_visitbp(td, dnp, buf, cbp, &czb);
+ err = traverse_visitbp(td, dnp, buf, &cbp[i], &czb);
if (err) {
if (!hard)
break;
@@ -267,11 +301,16 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err)
return (err);
+ dnp = buf->b_data;
+
+ for (i = 0; i < epb; i++) {
+ prefetch_dnode_metadata(td, &dnp[i], buf, zb->zb_objset,
+ zb->zb_blkid * epb + i);
+ }
/* recursively visitbp() blocks below this */
- dnp = buf->b_data;
- for (i = 0; i < epb; i++, dnp++) {
- err = traverse_dnode(td, dnp, buf, zb->zb_objset,
+ for (i = 0; i < epb; i++) {
+ err = traverse_dnode(td, &dnp[i], buf, zb->zb_objset,
zb->zb_blkid * epb + i);
if (err) {
if (!hard)
@@ -292,6 +331,15 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
osp = buf->b_data;
dnp = &osp->os_meta_dnode;
+ prefetch_dnode_metadata(td, dnp, buf, zb->zb_objset,
+ DMU_META_DNODE_OBJECT);
+ if (arc_buf_size(buf) >= sizeof (objset_phys_t)) {
+ prefetch_dnode_metadata(td, &osp->os_userused_dnode,
+ buf, zb->zb_objset, DMU_USERUSED_OBJECT);
+ prefetch_dnode_metadata(td, &osp->os_groupused_dnode,
+ buf, zb->zb_objset, DMU_USERUSED_OBJECT);
+ }
+
err = traverse_dnode(td, dnp, buf, zb->zb_objset,
DMU_META_DNODE_OBJECT);
if (err && hard) {
@@ -334,6 +382,24 @@ post:
return (err != 0 ? err : lasterr);
}
+static void
+prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
+ arc_buf_t *buf, uint64_t objset, uint64_t object)
+{
+ int j;
+ zbookmark_t czb;
+
+ for (j = 0; j < dnp->dn_nblkptr; j++) {
+ SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
+ traverse_prefetch_metadata(td, buf, &dnp->dn_blkptr[j], &czb);
+ }
+
+ if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
+ SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
+ traverse_prefetch_metadata(td, buf, &dnp->dn_spill, &czb);
+ }
+}
+
static int
traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
arc_buf_t *buf, uint64_t objset, uint64_t object)
@@ -344,8 +410,7 @@ traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
for (j = 0; j < dnp->dn_nblkptr; j++) {
SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
- err = traverse_visitbp(td, dnp, buf,
- (blkptr_t *)&dnp->dn_blkptr[j], &czb);
+ err = traverse_visitbp(td, dnp, buf, &dnp->dn_blkptr[j], &czb);
if (err) {
if (!hard)
break;
@@ -354,10 +419,8 @@ traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
- SET_BOOKMARK(&czb, objset,
- object, 0, DMU_SPILL_BLKID);
- err = traverse_visitbp(td, dnp, buf,
- (blkptr_t *)&dnp->dn_spill, &czb);
+ SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
+ err = traverse_visitbp(td, dnp, buf, &dnp->dn_spill, &czb);
if (err) {
if (!hard)
return (err);
@@ -438,6 +501,12 @@ traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
ASSERT(ds == NULL || objset == ds->ds_object);
ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST));
+ /*
+ * The data prefetching mechanism (the prefetch thread) is incompatible
+ * with resuming from a bookmark.
+ */
+ ASSERT(resume == NULL || !(flags & TRAVERSE_PREFETCH_DATA));
+
td = kmem_alloc(sizeof(traverse_data_t), KM_PUSHPAGE);
pd = kmem_zalloc(sizeof(prefetch_data_t), KM_PUSHPAGE);
czb = kmem_alloc(sizeof(zbookmark_t), KM_PUSHPAGE);
@@ -468,7 +537,7 @@ traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
traverse_zil(td, &os->os_zil_header);
}
- if (!(flags & TRAVERSE_PREFETCH) ||
+ if (!(flags & TRAVERSE_PREFETCH_DATA) ||
0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
td, TQ_NOQUEUE))
pd->pd_exited = B_TRUE;