New upstream version 0.7.6

[mirror_zfs-debian.git] / module / zfs / dbuf.c

diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index 62340469d3575b089fee6145fedf4201f733ce23..4ee121f5a5fbfdcdf0ad0320eb6bf15d43151532 100644 (file)
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -63,7 +63,6 @@ struct dbuf_hold_impl_data {
        blkptr_t *dh_bp;
        int dh_err;
        dbuf_dirty_record_t *dh_dr;
-       arc_buf_contents_t dh_type;
        int dh_depth;
 };
 
@@ -2484,6 +2483,10 @@ dbuf_prefetch_indirect_done(zio_t *zio, arc_buf_t *abuf, void *private)
                arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
                zbookmark_phys_t zb;
 
+               /* flag if L2ARC eligible, l2arc_noprefetch then decides */
+               if (dpa->dpa_aflags & ARC_FLAG_L2CACHE)
+                       iter_aflags |= ARC_FLAG_L2CACHE;
+
                ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
 
                SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset,
@@ -2597,6 +2600,10 @@ dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
        dpa->dpa_epbs = epbs;
        dpa->dpa_zio = pio;
 
+       /* flag if L2ARC eligible, l2arc_noprefetch then decides */
+       if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level))
+               dpa->dpa_aflags |= ARC_FLAG_L2CACHE;
+
        /*
         * If we have the indirect just above us, no need to do the asynchronous
         * prefetch chain; we'll just run the last step ourselves.  If we're at
@@ -2612,6 +2619,10 @@ dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
                arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
                zbookmark_phys_t zb;
 
+               /* flag if L2ARC eligible, l2arc_noprefetch then decides */
+               if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level))
+                       iter_aflags |= ARC_FLAG_L2CACHE;
+
                SET_BOOKMARK(&zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET,
                    dn->dn_object, curlevel, curblkid);
                (void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
@@ -2628,6 +2639,36 @@ dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
 
 #define        DBUF_HOLD_IMPL_MAX_DEPTH        20
 
+/*
+ * Helper function for __dbuf_hold_impl() to copy a buffer. Handles
+ * the case of compressed and uncompressed buffers by allocating the
+ * new buffer, respectively, with arc_alloc_raw_buf(),
+ * arc_alloc_compressed_buf() or arc_alloc_buf().*
+ *
+ * NOTE: Declared noinline to avoid stack bloat in __dbuf_hold_impl().
+ */
+noinline static void
+dbuf_hold_copy(struct dbuf_hold_impl_data *dh)
+{
+       dnode_t *dn = dh->dh_dn;
+       dmu_buf_impl_t *db = dh->dh_db;
+       dbuf_dirty_record_t *dr = dh->dh_dr;
+       arc_buf_t *data = dr->dt.dl.dr_data;
+
+       enum zio_compress compress_type = arc_get_compression(data);
+
+       if (compress_type != ZIO_COMPRESS_OFF) {
+               dbuf_set_data(db, arc_alloc_compressed_buf(
+                   dn->dn_objset->os_spa, db, arc_buf_size(data),
+                   arc_buf_lsize(data), compress_type));
+       } else {
+               dbuf_set_data(db, arc_alloc_buf(dn->dn_objset->os_spa, db,
+                   DBUF_GET_BUFC_TYPE(db), db->db.db_size));
+       }
+
+       bcopy(data->b_data, db->db.db_data, arc_buf_size(data));
+}
+
 /*
  * Returns with db_holds incremented, and db_mtx not held.
  * Note: dn_struct_rwlock must be held.
@@ -2678,8 +2719,10 @@ __dbuf_hold_impl(struct dbuf_hold_impl_data *dh)
                return (SET_ERROR(ENOENT));
        }
 
-       if (dh->dh_db->db_buf != NULL)
+       if (dh->dh_db->db_buf != NULL) {
+               arc_buf_access(dh->dh_db->db_buf);
                ASSERT3P(dh->dh_db->db.db_data, ==, dh->dh_db->db_buf->b_data);
+       }
 
        ASSERT(dh->dh_db->db_buf == NULL || arc_referenced(dh->dh_db->db_buf));
 
@@ -2693,16 +2736,8 @@ __dbuf_hold_impl(struct dbuf_hold_impl_data *dh)
            dh->dh_dn->dn_object != DMU_META_DNODE_OBJECT &&
            dh->dh_db->db_state == DB_CACHED && dh->dh_db->db_data_pending) {
                dh->dh_dr = dh->dh_db->db_data_pending;
-
-               if (dh->dh_dr->dt.dl.dr_data == dh->dh_db->db_buf) {
-                       dh->dh_type = DBUF_GET_BUFC_TYPE(dh->dh_db);
-
-                       dbuf_set_data(dh->dh_db,
-                           arc_alloc_buf(dh->dh_dn->dn_objset->os_spa,
-                           dh->dh_db, dh->dh_type, dh->dh_db->db.db_size));
-                       bcopy(dh->dh_dr->dt.dl.dr_data->b_data,
-                           dh->dh_db->db.db_data, dh->dh_db->db.db_size);
-               }
+               if (dh->dh_dr->dt.dl.dr_data == dh->dh_db->db_buf)
+                       dbuf_hold_copy(dh);
        }
 
        if (multilist_link_active(&dh->dh_db->db_cache_link)) {
@@ -2775,7 +2810,6 @@ __dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
        dh->dh_bp = NULL;
        dh->dh_err = 0;
        dh->dh_dr = NULL;
-       dh->dh_type = 0;
 
        dh->dh_depth = depth;
 }