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-rw-r--r--uts/common/fs/zfs/dmu_diff.c221
1 files changed, 221 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/dmu_diff.c b/uts/common/fs/zfs/dmu_diff.c
new file mode 100644
index 000000000000..22340ebc5374
--- /dev/null
+++ b/uts/common/fs/zfs/dmu_diff.c
@@ -0,0 +1,221 @@
+/*
+ * 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) 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/zfs_ioctl.h>
+#include <sys/zap.h>
+#include <sys/zio_checksum.h>
+#include <sys/zfs_znode.h>
+
+struct diffarg {
+ struct vnode *da_vp; /* file to which we are reporting */
+ offset_t *da_offp;
+ int da_err; /* error that stopped diff search */
+ dmu_diff_record_t da_ddr;
+};
+
+static int
+write_record(struct diffarg *da)
+{
+ ssize_t resid; /* have to get resid to get detailed errno */
+
+ if (da->da_ddr.ddr_type == DDR_NONE) {
+ da->da_err = 0;
+ return (0);
+ }
+
+ da->da_err = vn_rdwr(UIO_WRITE, da->da_vp, (caddr_t)&da->da_ddr,
+ sizeof (da->da_ddr), 0, UIO_SYSSPACE, FAPPEND,
+ RLIM64_INFINITY, CRED(), &resid);
+ *da->da_offp += sizeof (da->da_ddr);
+ return (da->da_err);
+}
+
+static int
+report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
+{
+ ASSERT(first <= last);
+ if (da->da_ddr.ddr_type != DDR_FREE ||
+ first != da->da_ddr.ddr_last + 1) {
+ if (write_record(da) != 0)
+ return (da->da_err);
+ da->da_ddr.ddr_type = DDR_FREE;
+ da->da_ddr.ddr_first = first;
+ da->da_ddr.ddr_last = last;
+ return (0);
+ }
+ da->da_ddr.ddr_last = last;
+ return (0);
+}
+
+static int
+report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
+{
+ ASSERT(dnp != NULL);
+ if (dnp->dn_type == DMU_OT_NONE)
+ return (report_free_dnode_range(da, object, object));
+
+ if (da->da_ddr.ddr_type != DDR_INUSE ||
+ object != da->da_ddr.ddr_last + 1) {
+ if (write_record(da) != 0)
+ return (da->da_err);
+ da->da_ddr.ddr_type = DDR_INUSE;
+ da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
+ return (0);
+ }
+ da->da_ddr.ddr_last = object;
+ return (0);
+}
+
+#define DBP_SPAN(dnp, level) \
+ (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
+ (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
+
+/* ARGSUSED */
+static int
+diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
+ const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
+{
+ struct diffarg *da = arg;
+ int err = 0;
+
+ if (issig(JUSTLOOKING) && issig(FORREAL))
+ return (EINTR);
+
+ if (zb->zb_object != DMU_META_DNODE_OBJECT)
+ return (0);
+
+ if (bp == NULL) {
+ uint64_t span = DBP_SPAN(dnp, zb->zb_level);
+ uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
+
+ err = report_free_dnode_range(da, dnobj,
+ dnobj + (span >> DNODE_SHIFT) - 1);
+ if (err)
+ return (err);
+ } else if (zb->zb_level == 0) {
+ dnode_phys_t *blk;
+ arc_buf_t *abuf;
+ uint32_t aflags = ARC_WAIT;
+ int blksz = BP_GET_LSIZE(bp);
+ int i;
+
+ if (dsl_read(NULL, spa, bp, pbuf,
+ arc_getbuf_func, &abuf, ZIO_PRIORITY_ASYNC_READ,
+ ZIO_FLAG_CANFAIL, &aflags, zb) != 0)
+ return (EIO);
+
+ blk = abuf->b_data;
+ for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
+ uint64_t dnobj = (zb->zb_blkid <<
+ (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
+ err = report_dnode(da, dnobj, blk+i);
+ if (err)
+ break;
+ }
+ (void) arc_buf_remove_ref(abuf, &abuf);
+ if (err)
+ return (err);
+ /* Don't care about the data blocks */
+ return (TRAVERSE_VISIT_NO_CHILDREN);
+ }
+ return (0);
+}
+
+int
+dmu_diff(objset_t *tosnap, objset_t *fromsnap, struct vnode *vp, offset_t *offp)
+{
+ struct diffarg da;
+ dsl_dataset_t *ds = tosnap->os_dsl_dataset;
+ dsl_dataset_t *fromds = fromsnap->os_dsl_dataset;
+ dsl_dataset_t *findds;
+ dsl_dataset_t *relds;
+ int err = 0;
+
+ /* make certain we are looking at snapshots */
+ if (!dsl_dataset_is_snapshot(ds) || !dsl_dataset_is_snapshot(fromds))
+ return (EINVAL);
+
+ /* fromsnap must be earlier and from the same lineage as tosnap */
+ if (fromds->ds_phys->ds_creation_txg >= ds->ds_phys->ds_creation_txg)
+ return (EXDEV);
+
+ relds = NULL;
+ findds = ds;
+
+ while (fromds->ds_dir != findds->ds_dir) {
+ dsl_pool_t *dp = ds->ds_dir->dd_pool;
+
+ if (!dsl_dir_is_clone(findds->ds_dir)) {
+ if (relds)
+ dsl_dataset_rele(relds, FTAG);
+ return (EXDEV);
+ }
+
+ rw_enter(&dp->dp_config_rwlock, RW_READER);
+ err = dsl_dataset_hold_obj(dp,
+ findds->ds_dir->dd_phys->dd_origin_obj, FTAG, &findds);
+ rw_exit(&dp->dp_config_rwlock);
+
+ if (relds)
+ dsl_dataset_rele(relds, FTAG);
+
+ if (err)
+ return (EXDEV);
+
+ relds = findds;
+ }
+
+ if (relds)
+ dsl_dataset_rele(relds, FTAG);
+
+ da.da_vp = vp;
+ da.da_offp = offp;
+ da.da_ddr.ddr_type = DDR_NONE;
+ da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
+ da.da_err = 0;
+
+ err = traverse_dataset(ds, fromds->ds_phys->ds_creation_txg,
+ TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, diff_cb, &da);
+
+ if (err) {
+ da.da_err = err;
+ } else {
+ /* we set the da.da_err we return as side-effect */
+ (void) write_record(&da);
+ }
+
+ return (da.da_err);
+}