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 http://www.opensolaris.org/os/licensing.
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, 2015 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
44 struct diffarg {
45 struct vnode *da_vp; /* file to which we are reporting */
46 offset_t *da_offp;
47 int da_err; /* error that stopped diff search */
48 dmu_diff_record_t da_ddr;
49 };
50
51 static int
write_record(struct diffarg * da)52 write_record(struct diffarg *da)
53 {
54 ssize_t resid; /* have to get resid to get detailed errno */
55
56 if (da->da_ddr.ddr_type == DDR_NONE) {
57 da->da_err = 0;
58 return (0);
59 }
60
61 da->da_err = vn_rdwr(UIO_WRITE, da->da_vp, (caddr_t)&da->da_ddr,
62 sizeof (da->da_ddr), 0, UIO_SYSSPACE, FAPPEND,
63 RLIM64_INFINITY, CRED(), &resid);
64 *da->da_offp += sizeof (da->da_ddr);
65 return (da->da_err);
66 }
67
68 static int
report_free_dnode_range(struct diffarg * da,uint64_t first,uint64_t last)69 report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
70 {
71 ASSERT(first <= last);
72 if (da->da_ddr.ddr_type != DDR_FREE ||
73 first != da->da_ddr.ddr_last + 1) {
74 if (write_record(da) != 0)
75 return (da->da_err);
76 da->da_ddr.ddr_type = DDR_FREE;
77 da->da_ddr.ddr_first = first;
78 da->da_ddr.ddr_last = last;
79 return (0);
80 }
81 da->da_ddr.ddr_last = last;
82 return (0);
83 }
84
85 static int
report_dnode(struct diffarg * da,uint64_t object,dnode_phys_t * dnp)86 report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
87 {
88 ASSERT(dnp != NULL);
89 if (dnp->dn_type == DMU_OT_NONE)
90 return (report_free_dnode_range(da, object, object));
91
92 if (da->da_ddr.ddr_type != DDR_INUSE ||
93 object != da->da_ddr.ddr_last + 1) {
94 if (write_record(da) != 0)
95 return (da->da_err);
96 da->da_ddr.ddr_type = DDR_INUSE;
97 da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
98 return (0);
99 }
100 da->da_ddr.ddr_last = object;
101 return (0);
102 }
103
104 #define DBP_SPAN(dnp, level) \
105 (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
106 (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
107
108 /* ARGSUSED */
109 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)110 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
111 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
112 {
113 struct diffarg *da = arg;
114 int err = 0;
115
116 if (issig(JUSTLOOKING) && issig(FORREAL))
117 return (SET_ERROR(EINTR));
118
119 if (bp == NULL || zb->zb_object != DMU_META_DNODE_OBJECT)
120 return (0);
121
122 if (BP_IS_HOLE(bp)) {
123 uint64_t span = DBP_SPAN(dnp, zb->zb_level);
124 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
125
126 err = report_free_dnode_range(da, dnobj,
127 dnobj + (span >> DNODE_SHIFT) - 1);
128 if (err)
129 return (err);
130 } else if (zb->zb_level == 0) {
131 dnode_phys_t *blk;
132 arc_buf_t *abuf;
133 arc_flags_t aflags = ARC_FLAG_WAIT;
134 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
135 int zio_flags = ZIO_FLAG_CANFAIL;
136 int i;
137
138 if (BP_IS_PROTECTED(bp))
139 zio_flags |= ZIO_FLAG_RAW;
140
141 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
142 ZIO_PRIORITY_ASYNC_READ, zio_flags, &aflags, zb) != 0)
143 return (SET_ERROR(EIO));
144
145 blk = abuf->b_data;
146 for (i = 0; i < epb; i += blk[i].dn_extra_slots + 1) {
147 uint64_t dnobj = (zb->zb_blkid <<
148 (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
149 err = report_dnode(da, dnobj, blk+i);
150 if (err)
151 break;
152 }
153 arc_buf_destroy(abuf, &abuf);
154 if (err)
155 return (err);
156 /* Don't care about the data blocks */
157 return (TRAVERSE_VISIT_NO_CHILDREN);
158 }
159 return (0);
160 }
161
162 int
dmu_diff(const char * tosnap_name,const char * fromsnap_name,struct vnode * vp,offset_t * offp)163 dmu_diff(const char *tosnap_name, const char *fromsnap_name,
164 struct vnode *vp, offset_t *offp)
165 {
166 struct diffarg da;
167 dsl_dataset_t *fromsnap;
168 dsl_dataset_t *tosnap;
169 dsl_pool_t *dp;
170 int error;
171 uint64_t fromtxg;
172
173 if (strchr(tosnap_name, '@') == NULL ||
174 strchr(fromsnap_name, '@') == NULL)
175 return (SET_ERROR(EINVAL));
176
177 error = dsl_pool_hold(tosnap_name, FTAG, &dp);
178 if (error != 0)
179 return (error);
180
181 error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
182 if (error != 0) {
183 dsl_pool_rele(dp, FTAG);
184 return (error);
185 }
186
187 error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
188 if (error != 0) {
189 dsl_dataset_rele(tosnap, FTAG);
190 dsl_pool_rele(dp, FTAG);
191 return (error);
192 }
193
194 if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
195 dsl_dataset_rele(fromsnap, FTAG);
196 dsl_dataset_rele(tosnap, FTAG);
197 dsl_pool_rele(dp, FTAG);
198 return (SET_ERROR(EXDEV));
199 }
200
201 fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
202 dsl_dataset_rele(fromsnap, FTAG);
203
204 dsl_dataset_long_hold(tosnap, FTAG);
205 dsl_pool_rele(dp, FTAG);
206
207 da.da_vp = vp;
208 da.da_offp = offp;
209 da.da_ddr.ddr_type = DDR_NONE;
210 da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
211 da.da_err = 0;
212
213 /*
214 * Since zfs diff only looks at dnodes which are stored in plaintext
215 * (other than bonus buffers), we don't technically need to decrypt
216 * the dataset to perform this operation. However, the command line
217 * utility will still fail if the keys are not loaded because the
218 * dataset isn't mounted and because it will fail when it attempts to
219 * call the ZFS_IOC_OBJ_TO_STATS ioctl.
220 */
221 error = traverse_dataset(tosnap, fromtxg,
222 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA | TRAVERSE_NO_DECRYPT,
223 diff_cb, &da);
224
225 if (error != 0) {
226 da.da_err = error;
227 } else {
228 /* we set the da.da_err we return as side-effect */
229 (void) write_record(&da);
230 }
231
232 dsl_dataset_long_rele(tosnap, FTAG);
233 dsl_dataset_rele(tosnap, FTAG);
234
235 return (da.da_err);
236 }
237