+static int
+get_next_chunk(dnode_t *dn, uint64_t *offset, uint64_t limit)
+{
+ uint64_t len = *offset - limit;
+ uint64_t chunk_len = dn->dn_datablksz * DMU_MAX_DELETEBLKCNT;
+ uint64_t subchunk =
+ dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
+
+ ASSERT(limit <= *offset);
+
+ if (len <= chunk_len) {
+ *offset = limit;
+ return (0);
+ }
+
+ ASSERT(ISP2(subchunk));
+
+ while (*offset > limit) {
+ uint64_t initial_offset = P2ROUNDUP(*offset, subchunk);
+ uint64_t delta;
+ int err;
+
+ /* skip over allocated data */
+ err = dnode_next_offset(dn,
+ DNODE_FIND_HOLE|DNODE_FIND_BACKWARDS, offset, 1, 1, 0);
+ if (err == ESRCH)
+ *offset = limit;
+ else if (err)
+ return (err);
+
+ ASSERT3U(*offset, <=, initial_offset);
+ *offset = P2ALIGN(*offset, subchunk);
+ delta = initial_offset - *offset;
+ if (delta >= chunk_len) {
+ *offset += delta - chunk_len;
+ return (0);
+ }
+ chunk_len -= delta;
+
+ /* skip over unallocated data */
+ err = dnode_next_offset(dn,
+ DNODE_FIND_BACKWARDS, offset, 1, 1, 0);
+ if (err == ESRCH)
+ *offset = limit;
+ else if (err)
+ return (err);
+
+ if (*offset < limit)
+ *offset = limit;
+ ASSERT3U(*offset, <, initial_offset);
+ }
+ return (0);
+}
+
+static int
+dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
+ uint64_t length, boolean_t free_dnode)
+{
+ dmu_tx_t *tx;
+ uint64_t object_size, start, end, len;
+ boolean_t trunc = (length == DMU_OBJECT_END);
+ int align, err;
+
+ align = 1 << dn->dn_datablkshift;
+ ASSERT(align > 0);
+ object_size = align == 1 ? dn->dn_datablksz :
+ (dn->dn_maxblkid + 1) << dn->dn_datablkshift;
+
+ if (trunc || (end = offset + length) > object_size)
+ end = object_size;
+ if (end <= offset)
+ return (0);
+ length = end - offset;
+
+ while (length) {
+ start = end;
+ err = get_next_chunk(dn, &start, offset);
+ if (err)
+ return (err);
+ len = trunc ? DMU_OBJECT_END : end - start;
+
+ tx = dmu_tx_create(os);
+ dmu_tx_hold_free(tx, dn->dn_object, start, len);
+ err = dmu_tx_assign(tx, TXG_WAIT);
+ if (err) {
+ dmu_tx_abort(tx);
+ return (err);
+ }
+
+ dnode_free_range(dn, start, trunc ? -1 : len, tx);
+
+ if (start == 0 && free_dnode) {
+ ASSERT(trunc);
+ dnode_free(dn, tx);
+ }
+
+ length -= end - start;
+
+ dmu_tx_commit(tx);
+ end = start;
+ }
+ return (0);
+}
+
+int
+dmu_free_long_range(objset_t *os, uint64_t object,
+ uint64_t offset, uint64_t length)
+{
+ dnode_t *dn;
+ int err;
+
+ err = dnode_hold(os->os, object, FTAG, &dn);
+ if (err != 0)
+ return (err);
+ err = dmu_free_long_range_impl(os, dn, offset, length, FALSE);
+ dnode_rele(dn, FTAG);
+ return (err);
+}
+
+int
+dmu_free_object(objset_t *os, uint64_t object)
+{
+ dnode_t *dn;
+ dmu_tx_t *tx;
+ int err;
+
+ err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,
+ FTAG, &dn);
+ if (err != 0)
+ return (err);
+ if (dn->dn_nlevels == 1) {
+ tx = dmu_tx_create(os);
+ dmu_tx_hold_bonus(tx, object);
+ dmu_tx_hold_free(tx, dn->dn_object, 0, DMU_OBJECT_END);
+ err = dmu_tx_assign(tx, TXG_WAIT);
+ if (err == 0) {
+ dnode_free_range(dn, 0, DMU_OBJECT_END, tx);
+ dnode_free(dn, tx);
+ dmu_tx_commit(tx);
+ } else {
+ dmu_tx_abort(tx);
+ }
+ } else {
+ err = dmu_free_long_range_impl(os, dn, 0, DMU_OBJECT_END, TRUE);
+ }
+ dnode_rele(dn, FTAG);
+ return (err);
+}
+