diff options
Diffstat (limited to 'module/zfs/dmu.c')
| -rw-r--r-- | module/zfs/dmu.c | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c index b4133f0e4..1bf108bfe 100644 --- a/module/zfs/dmu.c +++ b/module/zfs/dmu.c @@ -20,7 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2014 by Delphix. All rights reserved. + * Copyright (c) 2011, 2015 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2015 by Chunwei Chen. All rights reserved. @@ -386,7 +386,7 @@ dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp) */ static int dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, - int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags) + boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags) { dmu_buf_t **dbp; uint64_t blkid, nblks, i; @@ -396,15 +396,19 @@ dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, ASSERT(length <= DMU_MAX_ACCESS); - dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT; - if (flags & DMU_READ_NO_PREFETCH || length > zfetch_array_rd_sz) - dbuf_flags |= DB_RF_NOPREFETCH; + /* + * Note: We directly notify the prefetch code of this read, so that + * we can tell it about the multi-block read. dbuf_read() only knows + * about the one block it is accessing. + */ + dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT | + DB_RF_NOPREFETCH; rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_datablkshift) { int blkshift = dn->dn_datablkshift; - nblks = (P2ROUNDUP(offset+length, 1ULL<<blkshift) - - P2ALIGN(offset, 1ULL<<blkshift)) >> blkshift; + nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) - + P2ALIGN(offset, 1ULL << blkshift)) >> blkshift; } else { if (offset + length > dn->dn_datablksz) { zfs_panic_recover("zfs: accessing past end of object " @@ -423,19 +427,24 @@ dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL); blkid = dbuf_whichblock(dn, 0, offset); for (i = 0; i < nblks; i++) { - dmu_buf_impl_t *db = dbuf_hold(dn, blkid+i, tag); + dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag); if (db == NULL) { rw_exit(&dn->dn_struct_rwlock); dmu_buf_rele_array(dbp, nblks, tag); zio_nowait(zio); return (SET_ERROR(EIO)); } + /* initiate async i/o */ - if (read) { + if (read) (void) dbuf_read(db, zio, dbuf_flags); - } dbp[i] = &db->db; } + + if ((flags & DMU_READ_NO_PREFETCH) == 0 && read && + length < zfetch_array_rd_sz) { + dmu_zfetch(&dn->dn_zfetch, blkid, nblks); + } rw_exit(&dn->dn_struct_rwlock); /* wait for async i/o */ @@ -489,7 +498,8 @@ dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset, int dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset, - uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp) + uint64_t length, boolean_t read, void *tag, int *numbufsp, + dmu_buf_t ***dbpp) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; @@ -537,9 +547,6 @@ dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, uint64_t blkid; int nblks, err; - if (zfs_prefetch_disable) - return; - if (len == 0) { /* they're interested in the bonus buffer */ dn = DMU_META_DNODE(os); |