1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
25 * Copyright (c) 2019, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
26 */
27
28 #include <sys/dmu.h>
29 #include <sys/dmu_impl.h>
30 #include <sys/dmu_tx.h>
31 #include <sys/dbuf.h>
32 #include <sys/dnode.h>
33 #include <sys/zfs_context.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/dmu_traverse.h>
36 #include <sys/dsl_dataset.h>
37 #include <sys/dsl_dir.h>
38 #include <sys/dsl_pool.h>
39 #include <sys/dsl_synctask.h>
40 #include <sys/zfs_ioctl.h>
41 #include <sys/zap.h>
42 #include <sys/zio_checksum.h>
43 #include <sys/zfs_znode.h>
44 #include <sys/zfs_file.h>
45
46
47 typedef struct dmu_diffarg {
48 zfs_file_t *da_fp; /* file to which we are reporting */
49 offset_t *da_offp;
50 int da_err; /* error that stopped diff search */
51 dmu_diff_record_t da_ddr;
52 } dmu_diffarg_t;
53
54 static int
write_record(dmu_diffarg_t * da)55 write_record(dmu_diffarg_t *da)
56 {
57 zfs_file_t *fp;
58 ssize_t resid;
59
60 if (da->da_ddr.ddr_type == DDR_NONE) {
61 da->da_err = 0;
62 return (0);
63 }
64
65 fp = da->da_fp;
66 da->da_err = zfs_file_write(fp, (caddr_t)&da->da_ddr,
67 sizeof (da->da_ddr), &resid);
68 *da->da_offp += sizeof (da->da_ddr);
69 return (da->da_err);
70 }
71
72 static int
report_free_dnode_range(dmu_diffarg_t * da,uint64_t first,uint64_t last)73 report_free_dnode_range(dmu_diffarg_t *da, uint64_t first, uint64_t last)
74 {
75 ASSERT(first <= last);
76 if (da->da_ddr.ddr_type != DDR_FREE ||
77 first != da->da_ddr.ddr_last + 1) {
78 if (write_record(da) != 0)
79 return (da->da_err);
80 da->da_ddr.ddr_type = DDR_FREE;
81 da->da_ddr.ddr_first = first;
82 da->da_ddr.ddr_last = last;
83 return (0);
84 }
85 da->da_ddr.ddr_last = last;
86 return (0);
87 }
88
89 static int
report_dnode(dmu_diffarg_t * da,uint64_t object,dnode_phys_t * dnp)90 report_dnode(dmu_diffarg_t *da, uint64_t object, dnode_phys_t *dnp)
91 {
92 ASSERT(dnp != NULL);
93 if (dnp->dn_type == DMU_OT_NONE)
94 return (report_free_dnode_range(da, object, object));
95
96 if (da->da_ddr.ddr_type != DDR_INUSE ||
97 object != da->da_ddr.ddr_last + 1) {
98 if (write_record(da) != 0)
99 return (da->da_err);
100 da->da_ddr.ddr_type = DDR_INUSE;
101 da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
102 return (0);
103 }
104 da->da_ddr.ddr_last = object;
105 return (0);
106 }
107
108 #define DBP_SPAN(dnp, level) \
109 (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
110 (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
111
112 static int
diff_cb(spa_t * spa,zilog_t * zilog,const blkptr_t * bp,const zbookmark_phys_t * zb,const dnode_phys_t * dnp,void * arg)113 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
114 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
115 {
116 (void) zilog;
117 dmu_diffarg_t *da = arg;
118 int err = 0;
119
120 if (issig())
121 return (SET_ERROR(EINTR));
122
123 if (zb->zb_level == ZB_DNODE_LEVEL ||
124 zb->zb_object != DMU_META_DNODE_OBJECT)
125 return (0);
126
127 if (BP_IS_HOLE(bp)) {
128 uint64_t span = DBP_SPAN(dnp, zb->zb_level);
129 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
130
131 err = report_free_dnode_range(da, dnobj,
132 dnobj + (span >> DNODE_SHIFT) - 1);
133 if (err)
134 return (err);
135 } else if (zb->zb_level == 0) {
136 dnode_phys_t *blk;
137 arc_buf_t *abuf;
138 arc_flags_t aflags = ARC_FLAG_WAIT;
139 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
140 int zio_flags = ZIO_FLAG_CANFAIL;
141 int i;
142
143 if (BP_IS_PROTECTED(bp))
144 zio_flags |= ZIO_FLAG_RAW;
145
146 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
147 ZIO_PRIORITY_ASYNC_READ, zio_flags, &aflags, zb) != 0)
148 return (SET_ERROR(EIO));
149
150 blk = abuf->b_data;
151 for (i = 0; i < epb; i += blk[i].dn_extra_slots + 1) {
152 uint64_t dnobj = (zb->zb_blkid <<
153 (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
154 err = report_dnode(da, dnobj, blk+i);
155 if (err)
156 break;
157 }
158 arc_buf_destroy(abuf, &abuf);
159 if (err)
160 return (err);
161 /* Don't care about the data blocks */
162 return (TRAVERSE_VISIT_NO_CHILDREN);
163 }
164 return (0);
165 }
166
167 int
dmu_diff(const char * tosnap_name,const char * fromsnap_name,zfs_file_t * fp,offset_t * offp)168 dmu_diff(const char *tosnap_name, const char *fromsnap_name,
169 zfs_file_t *fp, offset_t *offp)
170 {
171 dmu_diffarg_t da;
172 dsl_dataset_t *fromsnap;
173 dsl_dataset_t *tosnap;
174 dsl_pool_t *dp;
175 int error;
176 uint64_t fromtxg;
177
178 if (strchr(tosnap_name, '@') == NULL ||
179 strchr(fromsnap_name, '@') == NULL)
180 return (SET_ERROR(EINVAL));
181
182 error = dsl_pool_hold(tosnap_name, FTAG, &dp);
183 if (error != 0)
184 return (error);
185
186 error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
187 if (error != 0) {
188 dsl_pool_rele(dp, FTAG);
189 return (error);
190 }
191
192 error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
193 if (error != 0) {
194 dsl_dataset_rele(tosnap, FTAG);
195 dsl_pool_rele(dp, FTAG);
196 return (error);
197 }
198
199 if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
200 dsl_dataset_rele(fromsnap, FTAG);
201 dsl_dataset_rele(tosnap, FTAG);
202 dsl_pool_rele(dp, FTAG);
203 return (SET_ERROR(EXDEV));
204 }
205
206 fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
207 dsl_dataset_rele(fromsnap, FTAG);
208
209 dsl_dataset_long_hold(tosnap, FTAG);
210 dsl_pool_rele(dp, FTAG);
211
212 da.da_fp = fp;
213 da.da_offp = offp;
214 da.da_ddr.ddr_type = DDR_NONE;
215 da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
216 da.da_err = 0;
217
218 /*
219 * Since zfs diff only looks at dnodes which are stored in plaintext
220 * (other than bonus buffers), we don't technically need to decrypt
221 * the dataset to perform this operation. However, the command line
222 * utility will still fail if the keys are not loaded because the
223 * dataset isn't mounted and because it will fail when it attempts to
224 * call the ZFS_IOC_OBJ_TO_STATS ioctl.
225 */
226 error = traverse_dataset(tosnap, fromtxg,
227 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA | TRAVERSE_NO_DECRYPT |
228 TRAVERSE_LOGICAL, diff_cb, &da);
229
230 if (error != 0) {
231 da.da_err = error;
232 } else {
233 /* we set the da.da_err we return as side-effect */
234 (void) write_record(&da);
235 }
236
237 dsl_dataset_long_rele(tosnap, FTAG);
238 dsl_dataset_rele(tosnap, FTAG);
239
240 return (da.da_err);
241 }
242