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