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-rw-r--r--uts/common/fs/zfs/dmu.c1764
1 files changed, 1764 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/dmu.c b/uts/common/fs/zfs/dmu.c
new file mode 100644
index 000000000000..39234eba53b2
--- /dev/null
+++ b/uts/common/fs/zfs/dmu.c
@@ -0,0 +1,1764 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <sys/dmu.h>
+#include <sys/dmu_impl.h>
+#include <sys/dmu_tx.h>
+#include <sys/dbuf.h>
+#include <sys/dnode.h>
+#include <sys/zfs_context.h>
+#include <sys/dmu_objset.h>
+#include <sys/dmu_traverse.h>
+#include <sys/dsl_dataset.h>
+#include <sys/dsl_dir.h>
+#include <sys/dsl_pool.h>
+#include <sys/dsl_synctask.h>
+#include <sys/dsl_prop.h>
+#include <sys/dmu_zfetch.h>
+#include <sys/zfs_ioctl.h>
+#include <sys/zap.h>
+#include <sys/zio_checksum.h>
+#include <sys/sa.h>
+#ifdef _KERNEL
+#include <sys/vmsystm.h>
+#include <sys/zfs_znode.h>
+#endif
+
+const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
+ { byteswap_uint8_array, TRUE, "unallocated" },
+ { zap_byteswap, TRUE, "object directory" },
+ { byteswap_uint64_array, TRUE, "object array" },
+ { byteswap_uint8_array, TRUE, "packed nvlist" },
+ { byteswap_uint64_array, TRUE, "packed nvlist size" },
+ { byteswap_uint64_array, TRUE, "bpobj" },
+ { byteswap_uint64_array, TRUE, "bpobj header" },
+ { byteswap_uint64_array, TRUE, "SPA space map header" },
+ { byteswap_uint64_array, TRUE, "SPA space map" },
+ { byteswap_uint64_array, TRUE, "ZIL intent log" },
+ { dnode_buf_byteswap, TRUE, "DMU dnode" },
+ { dmu_objset_byteswap, TRUE, "DMU objset" },
+ { byteswap_uint64_array, TRUE, "DSL directory" },
+ { zap_byteswap, TRUE, "DSL directory child map"},
+ { zap_byteswap, TRUE, "DSL dataset snap map" },
+ { zap_byteswap, TRUE, "DSL props" },
+ { byteswap_uint64_array, TRUE, "DSL dataset" },
+ { zfs_znode_byteswap, TRUE, "ZFS znode" },
+ { zfs_oldacl_byteswap, TRUE, "ZFS V0 ACL" },
+ { byteswap_uint8_array, FALSE, "ZFS plain file" },
+ { zap_byteswap, TRUE, "ZFS directory" },
+ { zap_byteswap, TRUE, "ZFS master node" },
+ { zap_byteswap, TRUE, "ZFS delete queue" },
+ { byteswap_uint8_array, FALSE, "zvol object" },
+ { zap_byteswap, TRUE, "zvol prop" },
+ { byteswap_uint8_array, FALSE, "other uint8[]" },
+ { byteswap_uint64_array, FALSE, "other uint64[]" },
+ { zap_byteswap, TRUE, "other ZAP" },
+ { zap_byteswap, TRUE, "persistent error log" },
+ { byteswap_uint8_array, TRUE, "SPA history" },
+ { byteswap_uint64_array, TRUE, "SPA history offsets" },
+ { zap_byteswap, TRUE, "Pool properties" },
+ { zap_byteswap, TRUE, "DSL permissions" },
+ { zfs_acl_byteswap, TRUE, "ZFS ACL" },
+ { byteswap_uint8_array, TRUE, "ZFS SYSACL" },
+ { byteswap_uint8_array, TRUE, "FUID table" },
+ { byteswap_uint64_array, TRUE, "FUID table size" },
+ { zap_byteswap, TRUE, "DSL dataset next clones"},
+ { zap_byteswap, TRUE, "scan work queue" },
+ { zap_byteswap, TRUE, "ZFS user/group used" },
+ { zap_byteswap, TRUE, "ZFS user/group quota" },
+ { zap_byteswap, TRUE, "snapshot refcount tags"},
+ { zap_byteswap, TRUE, "DDT ZAP algorithm" },
+ { zap_byteswap, TRUE, "DDT statistics" },
+ { byteswap_uint8_array, TRUE, "System attributes" },
+ { zap_byteswap, TRUE, "SA master node" },
+ { zap_byteswap, TRUE, "SA attr registration" },
+ { zap_byteswap, TRUE, "SA attr layouts" },
+ { zap_byteswap, TRUE, "scan translations" },
+ { byteswap_uint8_array, FALSE, "deduplicated block" },
+ { zap_byteswap, TRUE, "DSL deadlist map" },
+ { byteswap_uint64_array, TRUE, "DSL deadlist map hdr" },
+ { zap_byteswap, TRUE, "DSL dir clones" },
+ { byteswap_uint64_array, TRUE, "bpobj subobj" },
+};
+
+int
+dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
+ void *tag, dmu_buf_t **dbp, int flags)
+{
+ dnode_t *dn;
+ uint64_t blkid;
+ dmu_buf_impl_t *db;
+ int err;
+ int db_flags = DB_RF_CANFAIL;
+
+ if (flags & DMU_READ_NO_PREFETCH)
+ db_flags |= DB_RF_NOPREFETCH;
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+ blkid = dbuf_whichblock(dn, offset);
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ db = dbuf_hold(dn, blkid, tag);
+ rw_exit(&dn->dn_struct_rwlock);
+ if (db == NULL) {
+ err = EIO;
+ } else {
+ err = dbuf_read(db, NULL, db_flags);
+ if (err) {
+ dbuf_rele(db, tag);
+ db = NULL;
+ }
+ }
+
+ dnode_rele(dn, FTAG);
+ *dbp = &db->db; /* NULL db plus first field offset is NULL */
+ return (err);
+}
+
+int
+dmu_bonus_max(void)
+{
+ return (DN_MAX_BONUSLEN);
+}
+
+int
+dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dnode_t *dn;
+ int error;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+
+ if (dn->dn_bonus != db) {
+ error = EINVAL;
+ } else if (newsize < 0 || newsize > db_fake->db_size) {
+ error = EINVAL;
+ } else {
+ dnode_setbonuslen(dn, newsize, tx);
+ error = 0;
+ }
+
+ DB_DNODE_EXIT(db);
+ return (error);
+}
+
+int
+dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dnode_t *dn;
+ int error;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+
+ if (type > DMU_OT_NUMTYPES) {
+ error = EINVAL;
+ } else if (dn->dn_bonus != db) {
+ error = EINVAL;
+ } else {
+ dnode_setbonus_type(dn, type, tx);
+ error = 0;
+ }
+
+ DB_DNODE_EXIT(db);
+ return (error);
+}
+
+dmu_object_type_t
+dmu_get_bonustype(dmu_buf_t *db_fake)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dnode_t *dn;
+ dmu_object_type_t type;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ type = dn->dn_bonustype;
+ DB_DNODE_EXIT(db);
+
+ return (type);
+}
+
+int
+dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
+{
+ dnode_t *dn;
+ int error;
+
+ error = dnode_hold(os, object, FTAG, &dn);
+ dbuf_rm_spill(dn, tx);
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ dnode_rm_spill(dn, tx);
+ rw_exit(&dn->dn_struct_rwlock);
+ dnode_rele(dn, FTAG);
+ return (error);
+}
+
+/*
+ * returns ENOENT, EIO, or 0.
+ */
+int
+dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
+{
+ dnode_t *dn;
+ dmu_buf_impl_t *db;
+ int error;
+
+ error = dnode_hold(os, object, FTAG, &dn);
+ if (error)
+ return (error);
+
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ if (dn->dn_bonus == NULL) {
+ rw_exit(&dn->dn_struct_rwlock);
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ if (dn->dn_bonus == NULL)
+ dbuf_create_bonus(dn);
+ }
+ db = dn->dn_bonus;
+
+ /* as long as the bonus buf is held, the dnode will be held */
+ if (refcount_add(&db->db_holds, tag) == 1) {
+ VERIFY(dnode_add_ref(dn, db));
+ (void) atomic_inc_32_nv(&dn->dn_dbufs_count);
+ }
+
+ /*
+ * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
+ * hold and incrementing the dbuf count to ensure that dnode_move() sees
+ * a dnode hold for every dbuf.
+ */
+ rw_exit(&dn->dn_struct_rwlock);
+
+ dnode_rele(dn, FTAG);
+
+ VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH));
+
+ *dbp = &db->db;
+ return (0);
+}
+
+/*
+ * returns ENOENT, EIO, or 0.
+ *
+ * This interface will allocate a blank spill dbuf when a spill blk
+ * doesn't already exist on the dnode.
+ *
+ * if you only want to find an already existing spill db, then
+ * dmu_spill_hold_existing() should be used.
+ */
+int
+dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
+{
+ dmu_buf_impl_t *db = NULL;
+ int err;
+
+ if ((flags & DB_RF_HAVESTRUCT) == 0)
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+
+ db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
+
+ if ((flags & DB_RF_HAVESTRUCT) == 0)
+ rw_exit(&dn->dn_struct_rwlock);
+
+ ASSERT(db != NULL);
+ err = dbuf_read(db, NULL, flags);
+ if (err == 0)
+ *dbp = &db->db;
+ else
+ dbuf_rele(db, tag);
+ return (err);
+}
+
+int
+dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
+ dnode_t *dn;
+ int err;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+
+ if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
+ err = EINVAL;
+ } else {
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+
+ if (!dn->dn_have_spill) {
+ err = ENOENT;
+ } else {
+ err = dmu_spill_hold_by_dnode(dn,
+ DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
+ }
+
+ rw_exit(&dn->dn_struct_rwlock);
+ }
+
+ DB_DNODE_EXIT(db);
+ return (err);
+}
+
+int
+dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
+ dnode_t *dn;
+ int err;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ err = dmu_spill_hold_by_dnode(dn, DB_RF_CANFAIL, tag, dbp);
+ DB_DNODE_EXIT(db);
+
+ return (err);
+}
+
+/*
+ * Note: longer-term, we should modify all of the dmu_buf_*() interfaces
+ * to take a held dnode rather than <os, object> -- the lookup is wasteful,
+ * and can induce severe lock contention when writing to several files
+ * whose dnodes are in the same block.
+ */
+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)
+{
+ dsl_pool_t *dp = NULL;
+ dmu_buf_t **dbp;
+ uint64_t blkid, nblks, i;
+ uint32_t dbuf_flags;
+ int err;
+ zio_t *zio;
+ hrtime_t start;
+
+ 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;
+
+ 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;
+ } else {
+ if (offset + length > dn->dn_datablksz) {
+ zfs_panic_recover("zfs: accessing past end of object "
+ "%llx/%llx (size=%u access=%llu+%llu)",
+ (longlong_t)dn->dn_objset->
+ os_dsl_dataset->ds_object,
+ (longlong_t)dn->dn_object, dn->dn_datablksz,
+ (longlong_t)offset, (longlong_t)length);
+ rw_exit(&dn->dn_struct_rwlock);
+ return (EIO);
+ }
+ nblks = 1;
+ }
+ dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
+
+ if (dn->dn_objset->os_dsl_dataset)
+ dp = dn->dn_objset->os_dsl_dataset->ds_dir->dd_pool;
+ if (dp && dsl_pool_sync_context(dp))
+ start = gethrtime();
+ zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
+ blkid = dbuf_whichblock(dn, offset);
+ for (i = 0; i < nblks; i++) {
+ 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 (EIO);
+ }
+ /* initiate async i/o */
+ if (read) {
+ (void) dbuf_read(db, zio, dbuf_flags);
+ }
+ dbp[i] = &db->db;
+ }
+ rw_exit(&dn->dn_struct_rwlock);
+
+ /* wait for async i/o */
+ err = zio_wait(zio);
+ /* track read overhead when we are in sync context */
+ if (dp && dsl_pool_sync_context(dp))
+ dp->dp_read_overhead += gethrtime() - start;
+ if (err) {
+ dmu_buf_rele_array(dbp, nblks, tag);
+ return (err);
+ }
+
+ /* wait for other io to complete */
+ if (read) {
+ for (i = 0; i < nblks; i++) {
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
+ mutex_enter(&db->db_mtx);
+ while (db->db_state == DB_READ ||
+ db->db_state == DB_FILL)
+ cv_wait(&db->db_changed, &db->db_mtx);
+ if (db->db_state == DB_UNCACHED)
+ err = EIO;
+ mutex_exit(&db->db_mtx);
+ if (err) {
+ dmu_buf_rele_array(dbp, nblks, tag);
+ return (err);
+ }
+ }
+ }
+
+ *numbufsp = nblks;
+ *dbpp = dbp;
+ return (0);
+}
+
+static int
+dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
+ uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
+{
+ dnode_t *dn;
+ int err;
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+
+ err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
+ numbufsp, dbpp, DMU_READ_PREFETCH);
+
+ dnode_rele(dn, FTAG);
+
+ return (err);
+}
+
+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)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dnode_t *dn;
+ int err;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
+ numbufsp, dbpp, DMU_READ_PREFETCH);
+ DB_DNODE_EXIT(db);
+
+ return (err);
+}
+
+void
+dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
+{
+ int i;
+ dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
+
+ if (numbufs == 0)
+ return;
+
+ for (i = 0; i < numbufs; i++) {
+ if (dbp[i])
+ dbuf_rele(dbp[i], tag);
+ }
+
+ kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
+}
+
+void
+dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, uint64_t len)
+{
+ dnode_t *dn;
+ uint64_t blkid;
+ int nblks, i, err;
+
+ if (zfs_prefetch_disable)
+ return;
+
+ if (len == 0) { /* they're interested in the bonus buffer */
+ dn = DMU_META_DNODE(os);
+
+ if (object == 0 || object >= DN_MAX_OBJECT)
+ return;
+
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ blkid = dbuf_whichblock(dn, object * sizeof (dnode_phys_t));
+ dbuf_prefetch(dn, blkid);
+ rw_exit(&dn->dn_struct_rwlock);
+ return;
+ }
+
+ /*
+ * XXX - Note, if the dnode for the requested object is not
+ * already cached, we will do a *synchronous* read in the
+ * dnode_hold() call. The same is true for any indirects.
+ */
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err != 0)
+ return;
+
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ if (dn->dn_datablkshift) {
+ int blkshift = dn->dn_datablkshift;
+ nblks = (P2ROUNDUP(offset+len, 1<<blkshift) -
+ P2ALIGN(offset, 1<<blkshift)) >> blkshift;
+ } else {
+ nblks = (offset < dn->dn_datablksz);
+ }
+
+ if (nblks != 0) {
+ blkid = dbuf_whichblock(dn, offset);
+ for (i = 0; i < nblks; i++)
+ dbuf_prefetch(dn, blkid+i);
+ }
+
+ rw_exit(&dn->dn_struct_rwlock);
+
+ dnode_rele(dn, FTAG);
+}
+
+/*
+ * Get the next "chunk" of file data to free. We traverse the file from
+ * the end so that the file gets shorter over time (if we crashes in the
+ * middle, this will leave us in a better state). We find allocated file
+ * data by simply searching the allocated level 1 indirects.
+ */
+static int
+get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t limit)
+{
+ uint64_t len = *start - limit;
+ uint64_t blkcnt = 0;
+ uint64_t maxblks = DMU_MAX_ACCESS / (1ULL << (dn->dn_indblkshift + 1));
+ uint64_t iblkrange =
+ dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
+
+ ASSERT(limit <= *start);
+
+ if (len <= iblkrange * maxblks) {
+ *start = limit;
+ return (0);
+ }
+ ASSERT(ISP2(iblkrange));
+
+ while (*start > limit && blkcnt < maxblks) {
+ int err;
+
+ /* find next allocated L1 indirect */
+ err = dnode_next_offset(dn,
+ DNODE_FIND_BACKWARDS, start, 2, 1, 0);
+
+ /* if there are no more, then we are done */
+ if (err == ESRCH) {
+ *start = limit;
+ return (0);
+ } else if (err) {
+ return (err);
+ }
+ blkcnt += 1;
+
+ /* reset offset to end of "next" block back */
+ *start = P2ALIGN(*start, iblkrange);
+ if (*start <= limit)
+ *start = limit;
+ else
+ *start -= 1;
+ }
+ 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;
+
+ end = offset + length;
+ if (trunc || end > object_size)
+ end = object_size;
+ if (end <= offset)
+ return (0);
+ length = end - offset;
+
+ while (length) {
+ start = end;
+ /* assert(offset <= start) */
+ 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, 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, 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);
+}
+
+int
+dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
+ uint64_t size, dmu_tx_t *tx)
+{
+ dnode_t *dn;
+ int err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+ ASSERT(offset < UINT64_MAX);
+ ASSERT(size == -1ULL || size <= UINT64_MAX - offset);
+ dnode_free_range(dn, offset, size, tx);
+ dnode_rele(dn, FTAG);
+ return (0);
+}
+
+int
+dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+ void *buf, uint32_t flags)
+{
+ dnode_t *dn;
+ dmu_buf_t **dbp;
+ int numbufs, err;
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+
+ /*
+ * Deal with odd block sizes, where there can't be data past the first
+ * block. If we ever do the tail block optimization, we will need to
+ * handle that here as well.
+ */
+ if (dn->dn_maxblkid == 0) {
+ int newsz = offset > dn->dn_datablksz ? 0 :
+ MIN(size, dn->dn_datablksz - offset);
+ bzero((char *)buf + newsz, size - newsz);
+ size = newsz;
+ }
+
+ while (size > 0) {
+ uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
+ int i;
+
+ /*
+ * NB: we could do this block-at-a-time, but it's nice
+ * to be reading in parallel.
+ */
+ err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
+ TRUE, FTAG, &numbufs, &dbp, flags);
+ if (err)
+ break;
+
+ for (i = 0; i < numbufs; i++) {
+ int tocpy;
+ int bufoff;
+ dmu_buf_t *db = dbp[i];
+
+ ASSERT(size > 0);
+
+ bufoff = offset - db->db_offset;
+ tocpy = (int)MIN(db->db_size - bufoff, size);
+
+ bcopy((char *)db->db_data + bufoff, buf, tocpy);
+
+ offset += tocpy;
+ size -= tocpy;
+ buf = (char *)buf + tocpy;
+ }
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+ }
+ dnode_rele(dn, FTAG);
+ return (err);
+}
+
+void
+dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+ const void *buf, dmu_tx_t *tx)
+{
+ dmu_buf_t **dbp;
+ int numbufs, i;
+
+ if (size == 0)
+ return;
+
+ VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
+ FALSE, FTAG, &numbufs, &dbp));
+
+ for (i = 0; i < numbufs; i++) {
+ int tocpy;
+ int bufoff;
+ dmu_buf_t *db = dbp[i];
+
+ ASSERT(size > 0);
+
+ bufoff = offset - db->db_offset;
+ tocpy = (int)MIN(db->db_size - bufoff, size);
+
+ ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
+
+ if (tocpy == db->db_size)
+ dmu_buf_will_fill(db, tx);
+ else
+ dmu_buf_will_dirty(db, tx);
+
+ bcopy(buf, (char *)db->db_data + bufoff, tocpy);
+
+ if (tocpy == db->db_size)
+ dmu_buf_fill_done(db, tx);
+
+ offset += tocpy;
+ size -= tocpy;
+ buf = (char *)buf + tocpy;
+ }
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+}
+
+void
+dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+ dmu_tx_t *tx)
+{
+ dmu_buf_t **dbp;
+ int numbufs, i;
+
+ if (size == 0)
+ return;
+
+ VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
+ FALSE, FTAG, &numbufs, &dbp));
+
+ for (i = 0; i < numbufs; i++) {
+ dmu_buf_t *db = dbp[i];
+
+ dmu_buf_will_not_fill(db, tx);
+ }
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+}
+
+/*
+ * DMU support for xuio
+ */
+kstat_t *xuio_ksp = NULL;
+
+int
+dmu_xuio_init(xuio_t *xuio, int nblk)
+{
+ dmu_xuio_t *priv;
+ uio_t *uio = &xuio->xu_uio;
+
+ uio->uio_iovcnt = nblk;
+ uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
+
+ priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
+ priv->cnt = nblk;
+ priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
+ priv->iovp = uio->uio_iov;
+ XUIO_XUZC_PRIV(xuio) = priv;
+
+ if (XUIO_XUZC_RW(xuio) == UIO_READ)
+ XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
+ else
+ XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
+
+ return (0);
+}
+
+void
+dmu_xuio_fini(xuio_t *xuio)
+{
+ dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
+ int nblk = priv->cnt;
+
+ kmem_free(priv->iovp, nblk * sizeof (iovec_t));
+ kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
+ kmem_free(priv, sizeof (dmu_xuio_t));
+
+ if (XUIO_XUZC_RW(xuio) == UIO_READ)
+ XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
+ else
+ XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
+}
+
+/*
+ * Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
+ * and increase priv->next by 1.
+ */
+int
+dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
+{
+ struct iovec *iov;
+ uio_t *uio = &xuio->xu_uio;
+ dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
+ int i = priv->next++;
+
+ ASSERT(i < priv->cnt);
+ ASSERT(off + n <= arc_buf_size(abuf));
+ iov = uio->uio_iov + i;
+ iov->iov_base = (char *)abuf->b_data + off;
+ iov->iov_len = n;
+ priv->bufs[i] = abuf;
+ return (0);
+}
+
+int
+dmu_xuio_cnt(xuio_t *xuio)
+{
+ dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
+ return (priv->cnt);
+}
+
+arc_buf_t *
+dmu_xuio_arcbuf(xuio_t *xuio, int i)
+{
+ dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
+
+ ASSERT(i < priv->cnt);
+ return (priv->bufs[i]);
+}
+
+void
+dmu_xuio_clear(xuio_t *xuio, int i)
+{
+ dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
+
+ ASSERT(i < priv->cnt);
+ priv->bufs[i] = NULL;
+}
+
+static void
+xuio_stat_init(void)
+{
+ xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
+ KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
+ KSTAT_FLAG_VIRTUAL);
+ if (xuio_ksp != NULL) {
+ xuio_ksp->ks_data = &xuio_stats;
+ kstat_install(xuio_ksp);
+ }
+}
+
+static void
+xuio_stat_fini(void)
+{
+ if (xuio_ksp != NULL) {
+ kstat_delete(xuio_ksp);
+ xuio_ksp = NULL;
+ }
+}
+
+void
+xuio_stat_wbuf_copied()
+{
+ XUIOSTAT_BUMP(xuiostat_wbuf_copied);
+}
+
+void
+xuio_stat_wbuf_nocopy()
+{
+ XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
+}
+
+#ifdef _KERNEL
+int
+dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
+{
+ dmu_buf_t **dbp;
+ int numbufs, i, err;
+ xuio_t *xuio = NULL;
+
+ /*
+ * NB: we could do this block-at-a-time, but it's nice
+ * to be reading in parallel.
+ */
+ err = dmu_buf_hold_array(os, object, uio->uio_loffset, size, TRUE, FTAG,
+ &numbufs, &dbp);
+ if (err)
+ return (err);
+
+ if (uio->uio_extflg == UIO_XUIO)
+ xuio = (xuio_t *)uio;
+
+ for (i = 0; i < numbufs; i++) {
+ int tocpy;
+ int bufoff;
+ dmu_buf_t *db = dbp[i];
+
+ ASSERT(size > 0);
+
+ bufoff = uio->uio_loffset - db->db_offset;
+ tocpy = (int)MIN(db->db_size - bufoff, size);
+
+ if (xuio) {
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ arc_buf_t *dbuf_abuf = dbi->db_buf;
+ arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
+ err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
+ if (!err) {
+ uio->uio_resid -= tocpy;
+ uio->uio_loffset += tocpy;
+ }
+
+ if (abuf == dbuf_abuf)
+ XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
+ else
+ XUIOSTAT_BUMP(xuiostat_rbuf_copied);
+ } else {
+ err = uiomove((char *)db->db_data + bufoff, tocpy,
+ UIO_READ, uio);
+ }
+ if (err)
+ break;
+
+ size -= tocpy;
+ }
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+
+ return (err);
+}
+
+static int
+dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
+{
+ dmu_buf_t **dbp;
+ int numbufs;
+ int err = 0;
+ int i;
+
+ err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
+ FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
+ if (err)
+ return (err);
+
+ for (i = 0; i < numbufs; i++) {
+ int tocpy;
+ int bufoff;
+ dmu_buf_t *db = dbp[i];
+
+ ASSERT(size > 0);
+
+ bufoff = uio->uio_loffset - db->db_offset;
+ tocpy = (int)MIN(db->db_size - bufoff, size);
+
+ ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
+
+ if (tocpy == db->db_size)
+ dmu_buf_will_fill(db, tx);
+ else
+ dmu_buf_will_dirty(db, tx);
+
+ /*
+ * XXX uiomove could block forever (eg. nfs-backed
+ * pages). There needs to be a uiolockdown() function
+ * to lock the pages in memory, so that uiomove won't
+ * block.
+ */
+ err = uiomove((char *)db->db_data + bufoff, tocpy,
+ UIO_WRITE, uio);
+
+ if (tocpy == db->db_size)
+ dmu_buf_fill_done(db, tx);
+
+ if (err)
+ break;
+
+ size -= tocpy;
+ }
+
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+ return (err);
+}
+
+int
+dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
+ dmu_tx_t *tx)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
+ dnode_t *dn;
+ int err;
+
+ if (size == 0)
+ return (0);
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ err = dmu_write_uio_dnode(dn, uio, size, tx);
+ DB_DNODE_EXIT(db);
+
+ return (err);
+}
+
+int
+dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
+ dmu_tx_t *tx)
+{
+ dnode_t *dn;
+ int err;
+
+ if (size == 0)
+ return (0);
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+
+ err = dmu_write_uio_dnode(dn, uio, size, tx);
+
+ dnode_rele(dn, FTAG);
+
+ return (err);
+}
+
+int
+dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+ page_t *pp, dmu_tx_t *tx)
+{
+ dmu_buf_t **dbp;
+ int numbufs, i;
+ int err;
+
+ if (size == 0)
+ return (0);
+
+ err = dmu_buf_hold_array(os, object, offset, size,
+ FALSE, FTAG, &numbufs, &dbp);
+ if (err)
+ return (err);
+
+ for (i = 0; i < numbufs; i++) {
+ int tocpy, copied, thiscpy;
+ int bufoff;
+ dmu_buf_t *db = dbp[i];
+ caddr_t va;
+
+ ASSERT(size > 0);
+ ASSERT3U(db->db_size, >=, PAGESIZE);
+
+ bufoff = offset - db->db_offset;
+ tocpy = (int)MIN(db->db_size - bufoff, size);
+
+ ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
+
+ if (tocpy == db->db_size)
+ dmu_buf_will_fill(db, tx);
+ else
+ dmu_buf_will_dirty(db, tx);
+
+ for (copied = 0; copied < tocpy; copied += PAGESIZE) {
+ ASSERT3U(pp->p_offset, ==, db->db_offset + bufoff);
+ thiscpy = MIN(PAGESIZE, tocpy - copied);
+ va = zfs_map_page(pp, S_READ);
+ bcopy(va, (char *)db->db_data + bufoff, thiscpy);
+ zfs_unmap_page(pp, va);
+ pp = pp->p_next;
+ bufoff += PAGESIZE;
+ }
+
+ if (tocpy == db->db_size)
+ dmu_buf_fill_done(db, tx);
+
+ offset += tocpy;
+ size -= tocpy;
+ }
+ dmu_buf_rele_array(dbp, numbufs, FTAG);
+ return (err);
+}
+#endif
+
+/*
+ * Allocate a loaned anonymous arc buffer.
+ */
+arc_buf_t *
+dmu_request_arcbuf(dmu_buf_t *handle, int size)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
+ spa_t *spa;
+
+ DB_GET_SPA(&spa, db);
+ return (arc_loan_buf(spa, size));
+}
+
+/*
+ * Free a loaned arc buffer.
+ */
+void
+dmu_return_arcbuf(arc_buf_t *buf)
+{
+ arc_return_buf(buf, FTAG);
+ VERIFY(arc_buf_remove_ref(buf, FTAG) == 1);
+}
+
+/*
+ * When possible directly assign passed loaned arc buffer to a dbuf.
+ * If this is not possible copy the contents of passed arc buf via
+ * dmu_write().
+ */
+void
+dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
+ dmu_tx_t *tx)
+{
+ dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
+ dnode_t *dn;
+ dmu_buf_impl_t *db;
+ uint32_t blksz = (uint32_t)arc_buf_size(buf);
+ uint64_t blkid;
+
+ DB_DNODE_ENTER(dbuf);
+ dn = DB_DNODE(dbuf);
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ blkid = dbuf_whichblock(dn, offset);
+ VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
+ rw_exit(&dn->dn_struct_rwlock);
+ DB_DNODE_EXIT(dbuf);
+
+ if (offset == db->db.db_offset && blksz == db->db.db_size) {
+ dbuf_assign_arcbuf(db, buf, tx);
+ dbuf_rele(db, FTAG);
+ } else {
+ objset_t *os;
+ uint64_t object;
+
+ DB_DNODE_ENTER(dbuf);
+ dn = DB_DNODE(dbuf);
+ os = dn->dn_objset;
+ object = dn->dn_object;
+ DB_DNODE_EXIT(dbuf);
+
+ dbuf_rele(db, FTAG);
+ dmu_write(os, object, offset, blksz, buf->b_data, tx);
+ dmu_return_arcbuf(buf);
+ XUIOSTAT_BUMP(xuiostat_wbuf_copied);
+ }
+}
+
+typedef struct {
+ dbuf_dirty_record_t *dsa_dr;
+ dmu_sync_cb_t *dsa_done;
+ zgd_t *dsa_zgd;
+ dmu_tx_t *dsa_tx;
+} dmu_sync_arg_t;
+
+/* ARGSUSED */
+static void
+dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
+{
+ dmu_sync_arg_t *dsa = varg;
+ dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
+ blkptr_t *bp = zio->io_bp;
+
+ if (zio->io_error == 0) {
+ if (BP_IS_HOLE(bp)) {
+ /*
+ * A block of zeros may compress to a hole, but the
+ * block size still needs to be known for replay.
+ */
+ BP_SET_LSIZE(bp, db->db_size);
+ } else {
+ ASSERT(BP_GET_LEVEL(bp) == 0);
+ bp->blk_fill = 1;
+ }
+ }
+}
+
+static void
+dmu_sync_late_arrival_ready(zio_t *zio)
+{
+ dmu_sync_ready(zio, NULL, zio->io_private);
+}
+
+/* ARGSUSED */
+static void
+dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
+{
+ dmu_sync_arg_t *dsa = varg;
+ dbuf_dirty_record_t *dr = dsa->dsa_dr;
+ dmu_buf_impl_t *db = dr->dr_dbuf;
+
+ mutex_enter(&db->db_mtx);
+ ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
+ if (zio->io_error == 0) {
+ dr->dt.dl.dr_overridden_by = *zio->io_bp;
+ dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
+ dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
+ if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by))
+ BP_ZERO(&dr->dt.dl.dr_overridden_by);
+ } else {
+ dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
+ }
+ cv_broadcast(&db->db_changed);
+ mutex_exit(&db->db_mtx);
+
+ dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
+
+ kmem_free(dsa, sizeof (*dsa));
+}
+
+static void
+dmu_sync_late_arrival_done(zio_t *zio)
+{
+ blkptr_t *bp = zio->io_bp;
+ dmu_sync_arg_t *dsa = zio->io_private;
+
+ if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
+ ASSERT(zio->io_bp->blk_birth == zio->io_txg);
+ ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
+ zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
+ }
+
+ dmu_tx_commit(dsa->dsa_tx);
+
+ dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
+
+ kmem_free(dsa, sizeof (*dsa));
+}
+
+static int
+dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
+ zio_prop_t *zp, zbookmark_t *zb)
+{
+ dmu_sync_arg_t *dsa;
+ dmu_tx_t *tx;
+
+ tx = dmu_tx_create(os);
+ dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
+ if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
+ dmu_tx_abort(tx);
+ return (EIO); /* Make zl_get_data do txg_waited_synced() */
+ }
+
+ dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
+ dsa->dsa_dr = NULL;
+ dsa->dsa_done = done;
+ dsa->dsa_zgd = zgd;
+ dsa->dsa_tx = tx;
+
+ zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
+ zgd->zgd_db->db_data, zgd->zgd_db->db_size, zp,
+ dmu_sync_late_arrival_ready, dmu_sync_late_arrival_done, dsa,
+ ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
+
+ return (0);
+}
+
+/*
+ * Intent log support: sync the block associated with db to disk.
+ * N.B. and XXX: the caller is responsible for making sure that the
+ * data isn't changing while dmu_sync() is writing it.
+ *
+ * Return values:
+ *
+ * EEXIST: this txg has already been synced, so there's nothing to to.
+ * The caller should not log the write.
+ *
+ * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
+ * The caller should not log the write.
+ *
+ * EALREADY: this block is already in the process of being synced.
+ * The caller should track its progress (somehow).
+ *
+ * EIO: could not do the I/O.
+ * The caller should do a txg_wait_synced().
+ *
+ * 0: the I/O has been initiated.
+ * The caller should log this blkptr in the done callback.
+ * It is possible that the I/O will fail, in which case
+ * the error will be reported to the done callback and
+ * propagated to pio from zio_done().
+ */
+int
+dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
+{
+ blkptr_t *bp = zgd->zgd_bp;
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
+ objset_t *os = db->db_objset;
+ dsl_dataset_t *ds = os->os_dsl_dataset;
+ dbuf_dirty_record_t *dr;
+ dmu_sync_arg_t *dsa;
+ zbookmark_t zb;
+ zio_prop_t zp;
+ dnode_t *dn;
+
+ ASSERT(pio != NULL);
+ ASSERT(BP_IS_HOLE(bp));
+ ASSERT(txg != 0);
+
+ SET_BOOKMARK(&zb, ds->ds_object,
+ db->db.db_object, db->db_level, db->db_blkid);
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
+ DB_DNODE_EXIT(db);
+
+ /*
+ * If we're frozen (running ziltest), we always need to generate a bp.
+ */
+ if (txg > spa_freeze_txg(os->os_spa))
+ return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
+
+ /*
+ * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
+ * and us. If we determine that this txg is not yet syncing,
+ * but it begins to sync a moment later, that's OK because the
+ * sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
+ */
+ mutex_enter(&db->db_mtx);
+
+ if (txg <= spa_last_synced_txg(os->os_spa)) {
+ /*
+ * This txg has already synced. There's nothing to do.
+ */
+ mutex_exit(&db->db_mtx);
+ return (EEXIST);
+ }
+
+ if (txg <= spa_syncing_txg(os->os_spa)) {
+ /*
+ * This txg is currently syncing, so we can't mess with
+ * the dirty record anymore; just write a new log block.
+ */
+ mutex_exit(&db->db_mtx);
+ return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
+ }
+
+ dr = db->db_last_dirty;
+ while (dr && dr->dr_txg != txg)
+ dr = dr->dr_next;
+
+ if (dr == NULL) {
+ /*
+ * There's no dr for this dbuf, so it must have been freed.
+ * There's no need to log writes to freed blocks, so we're done.
+ */
+ mutex_exit(&db->db_mtx);
+ return (ENOENT);
+ }
+
+ ASSERT(dr->dr_txg == txg);
+ if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
+ dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
+ /*
+ * We have already issued a sync write for this buffer,
+ * or this buffer has already been synced. It could not
+ * have been dirtied since, or we would have cleared the state.
+ */
+ mutex_exit(&db->db_mtx);
+ return (EALREADY);
+ }
+
+ ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
+ dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
+ mutex_exit(&db->db_mtx);
+
+ dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
+ dsa->dsa_dr = dr;
+ dsa->dsa_done = done;
+ dsa->dsa_zgd = zgd;
+ dsa->dsa_tx = NULL;
+
+ zio_nowait(arc_write(pio, os->os_spa, txg,
+ bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db), &zp,
+ dmu_sync_ready, dmu_sync_done, dsa,
+ ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
+
+ return (0);
+}
+
+int
+dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
+ dmu_tx_t *tx)
+{
+ dnode_t *dn;
+ int err;
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+ err = dnode_set_blksz(dn, size, ibs, tx);
+ dnode_rele(dn, FTAG);
+ return (err);
+}
+
+void
+dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
+ dmu_tx_t *tx)
+{
+ dnode_t *dn;
+
+ /* XXX assumes dnode_hold will not get an i/o error */
+ (void) dnode_hold(os, object, FTAG, &dn);
+ ASSERT(checksum < ZIO_CHECKSUM_FUNCTIONS);
+ dn->dn_checksum = checksum;
+ dnode_setdirty(dn, tx);
+ dnode_rele(dn, FTAG);
+}
+
+void
+dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
+ dmu_tx_t *tx)
+{
+ dnode_t *dn;
+
+ /* XXX assumes dnode_hold will not get an i/o error */
+ (void) dnode_hold(os, object, FTAG, &dn);
+ ASSERT(compress < ZIO_COMPRESS_FUNCTIONS);
+ dn->dn_compress = compress;
+ dnode_setdirty(dn, tx);
+ dnode_rele(dn, FTAG);
+}
+
+int zfs_mdcomp_disable = 0;
+
+void
+dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
+{
+ dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
+ boolean_t ismd = (level > 0 || dmu_ot[type].ot_metadata ||
+ (wp & WP_SPILL));
+ enum zio_checksum checksum = os->os_checksum;
+ enum zio_compress compress = os->os_compress;
+ enum zio_checksum dedup_checksum = os->os_dedup_checksum;
+ boolean_t dedup;
+ boolean_t dedup_verify = os->os_dedup_verify;
+ int copies = os->os_copies;
+
+ /*
+ * Determine checksum setting.
+ */
+ if (ismd) {
+ /*
+ * Metadata always gets checksummed. If the data
+ * checksum is multi-bit correctable, and it's not a
+ * ZBT-style checksum, then it's suitable for metadata
+ * as well. Otherwise, the metadata checksum defaults
+ * to fletcher4.
+ */
+ if (zio_checksum_table[checksum].ci_correctable < 1 ||
+ zio_checksum_table[checksum].ci_eck)
+ checksum = ZIO_CHECKSUM_FLETCHER_4;
+ } else {
+ checksum = zio_checksum_select(dn->dn_checksum, checksum);
+ }
+
+ /*
+ * Determine compression setting.
+ */
+ if (ismd) {
+ /*
+ * XXX -- we should design a compression algorithm
+ * that specializes in arrays of bps.
+ */
+ compress = zfs_mdcomp_disable ? ZIO_COMPRESS_EMPTY :
+ ZIO_COMPRESS_LZJB;
+ } else {
+ compress = zio_compress_select(dn->dn_compress, compress);
+ }
+
+ /*
+ * Determine dedup setting. If we are in dmu_sync(), we won't
+ * actually dedup now because that's all done in syncing context;
+ * but we do want to use the dedup checkum. If the checksum is not
+ * strong enough to ensure unique signatures, force dedup_verify.
+ */
+ dedup = (!ismd && dedup_checksum != ZIO_CHECKSUM_OFF);
+ if (dedup) {
+ checksum = dedup_checksum;
+ if (!zio_checksum_table[checksum].ci_dedup)
+ dedup_verify = 1;
+ }
+
+ if (wp & WP_DMU_SYNC)
+ dedup = 0;
+
+ if (wp & WP_NOFILL) {
+ ASSERT(!ismd && level == 0);
+ checksum = ZIO_CHECKSUM_OFF;
+ compress = ZIO_COMPRESS_OFF;
+ dedup = B_FALSE;
+ }
+
+ zp->zp_checksum = checksum;
+ zp->zp_compress = compress;
+ zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
+ zp->zp_level = level;
+ zp->zp_copies = MIN(copies + ismd, spa_max_replication(os->os_spa));
+ zp->zp_dedup = dedup;
+ zp->zp_dedup_verify = dedup && dedup_verify;
+}
+
+int
+dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
+{
+ dnode_t *dn;
+ int i, err;
+
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+ /*
+ * Sync any current changes before
+ * we go trundling through the block pointers.
+ */
+ for (i = 0; i < TXG_SIZE; i++) {
+ if (list_link_active(&dn->dn_dirty_link[i]))
+ break;
+ }
+ if (i != TXG_SIZE) {
+ dnode_rele(dn, FTAG);
+ txg_wait_synced(dmu_objset_pool(os), 0);
+ err = dnode_hold(os, object, FTAG, &dn);
+ if (err)
+ return (err);
+ }
+
+ err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
+ dnode_rele(dn, FTAG);
+
+ return (err);
+}
+
+void
+dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
+{
+ dnode_phys_t *dnp;
+
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ mutex_enter(&dn->dn_mtx);
+
+ dnp = dn->dn_phys;
+
+ doi->doi_data_block_size = dn->dn_datablksz;
+ doi->doi_metadata_block_size = dn->dn_indblkshift ?
+ 1ULL << dn->dn_indblkshift : 0;
+ doi->doi_type = dn->dn_type;
+ doi->doi_bonus_type = dn->dn_bonustype;
+ doi->doi_bonus_size = dn->dn_bonuslen;
+ doi->doi_indirection = dn->dn_nlevels;
+ doi->doi_checksum = dn->dn_checksum;
+ doi->doi_compress = dn->dn_compress;
+ doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
+ doi->doi_max_offset = (dnp->dn_maxblkid + 1) * dn->dn_datablksz;
+ doi->doi_fill_count = 0;
+ for (int i = 0; i < dnp->dn_nblkptr; i++)
+ doi->doi_fill_count += dnp->dn_blkptr[i].blk_fill;
+
+ mutex_exit(&dn->dn_mtx);
+ rw_exit(&dn->dn_struct_rwlock);
+}
+
+/*
+ * Get information on a DMU object.
+ * If doi is NULL, just indicates whether the object exists.
+ */
+int
+dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
+{
+ dnode_t *dn;
+ int err = dnode_hold(os, object, FTAG, &dn);
+
+ if (err)
+ return (err);
+
+ if (doi != NULL)
+ dmu_object_info_from_dnode(dn, doi);
+
+ dnode_rele(dn, FTAG);
+ return (0);
+}
+
+/*
+ * As above, but faster; can be used when you have a held dbuf in hand.
+ */
+void
+dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+
+ DB_DNODE_ENTER(db);
+ dmu_object_info_from_dnode(DB_DNODE(db), doi);
+ DB_DNODE_EXIT(db);
+}
+
+/*
+ * Faster still when you only care about the size.
+ * This is specifically optimized for zfs_getattr().
+ */
+void
+dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
+ u_longlong_t *nblk512)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dnode_t *dn;
+
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+
+ *blksize = dn->dn_datablksz;
+ /* add 1 for dnode space */
+ *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
+ SPA_MINBLOCKSHIFT) + 1;
+ DB_DNODE_EXIT(db);
+}
+
+void
+byteswap_uint64_array(void *vbuf, size_t size)
+{
+ uint64_t *buf = vbuf;
+ size_t count = size >> 3;
+ int i;
+
+ ASSERT((size & 7) == 0);
+
+ for (i = 0; i < count; i++)
+ buf[i] = BSWAP_64(buf[i]);
+}
+
+void
+byteswap_uint32_array(void *vbuf, size_t size)
+{
+ uint32_t *buf = vbuf;
+ size_t count = size >> 2;
+ int i;
+
+ ASSERT((size & 3) == 0);
+
+ for (i = 0; i < count; i++)
+ buf[i] = BSWAP_32(buf[i]);
+}
+
+void
+byteswap_uint16_array(void *vbuf, size_t size)
+{
+ uint16_t *buf = vbuf;
+ size_t count = size >> 1;
+ int i;
+
+ ASSERT((size & 1) == 0);
+
+ for (i = 0; i < count; i++)
+ buf[i] = BSWAP_16(buf[i]);
+}
+
+/* ARGSUSED */
+void
+byteswap_uint8_array(void *vbuf, size_t size)
+{
+}
+
+void
+dmu_init(void)
+{
+ zfs_dbgmsg_init();
+ sa_cache_init();
+ xuio_stat_init();
+ dmu_objset_init();
+ dnode_init();
+ dbuf_init();
+ zfetch_init();
+ arc_init();
+ l2arc_init();
+}
+
+void
+dmu_fini(void)
+{
+ l2arc_fini();
+ arc_fini();
+ zfetch_fini();
+ dbuf_fini();
+ dnode_fini();
+ dmu_objset_fini();
+ xuio_stat_fini();
+ sa_cache_fini();
+ zfs_dbgmsg_fini();
+}