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| author | Matthew Ahrens <mahrens@delphix.com> | 2017-04-13 14:35:08 -0700 |
|---|---|---|
| committer | Matthew Ahrens <mahrens@delphix.com> | 2017-04-18 13:12:30 -0700 |
| commit | def4fac5882b4ca67bd0f4a53509b6d1fa8ae14e (patch) | |
| tree | 95a6f97fa570025879d09341f619d981b5f6bd36 /usr/src | |
| parent | 2aa3758198f9de45e699e6e7426920958f9ecf8f (diff) | |
| download | illumos-gate-def4fac5882b4ca67bd0f4a53509b6d1fa8ae14e.tar.gz | |
8025 dbuf_read() creates unnecessary zio_root() for bonus buf
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Diffstat (limited to 'usr/src')
| -rw-r--r-- | usr/src/uts/common/fs/zfs/dbuf.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/usr/src/uts/common/fs/zfs/dbuf.c b/usr/src/uts/common/fs/zfs/dbuf.c index c8a981d512..bd01d57c0a 100644 --- a/usr/src/uts/common/fs/zfs/dbuf.c +++ b/usr/src/uts/common/fs/zfs/dbuf.c @@ -1088,7 +1088,6 @@ int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) { int err = 0; - boolean_t havepzio = (zio != NULL); boolean_t prefetch; dnode_t *dn; @@ -1132,9 +1131,13 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) DB_DNODE_EXIT(db); } else if (db->db_state == DB_UNCACHED) { spa_t *spa = dn->dn_objset->os_spa; + boolean_t need_wait = B_FALSE; - if (zio == NULL) + if (zio == NULL && + db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) { zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); + need_wait = B_TRUE; + } dbuf_read_impl(db, zio, flags); /* dbuf_read_impl has dropped db_mtx for us */ @@ -1146,7 +1149,7 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) rw_exit(&dn->dn_struct_rwlock); DB_DNODE_EXIT(db); - if (!havepzio) + if (need_wait) err = zio_wait(zio); } else { /* @@ -1181,7 +1184,6 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) mutex_exit(&db->db_mtx); } - ASSERT(err || havepzio || db->db_state == DB_CACHED); return (err); } |