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, 2014 by Delphix. All rights reserved.
24 */
25
26 #include <sys/dmu.h>
27 #include <sys/dmu_impl.h>
28 #include <sys/dmu_tx.h>
29 #include <sys/dbuf.h>
30 #include <sys/dnode.h>
31 #include <sys/zfs_context.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dmu_traverse.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dsl_pool.h>
37 #include <sys/dsl_synctask.h>
38 #include <sys/zfs_ioctl.h>
39 #include <sys/zap.h>
40 #include <sys/zio_checksum.h>
41 #include <sys/zfs_znode.h>
42
43 struct diffarg {
44 struct vnode *da_vp; /* file to which we are reporting */
45 offset_t *da_offp;
46 int da_err; /* error that stopped diff search */
47 dmu_diff_record_t da_ddr;
48 };
49
50 static int
write_record(struct diffarg * da)51 write_record(struct diffarg *da)
52 {
53 ssize_t resid; /* have to get resid to get detailed errno */
54
55 if (da->da_ddr.ddr_type == DDR_NONE) {
56 da->da_err = 0;
57 return (0);
58 }
59
60 da->da_err = vn_rdwr(UIO_WRITE, da->da_vp, (caddr_t)&da->da_ddr,
61 sizeof (da->da_ddr), 0, UIO_SYSSPACE, FAPPEND,
62 RLIM64_INFINITY, CRED(), &resid);
63 *da->da_offp += sizeof (da->da_ddr);
64 return (da->da_err);
65 }
66
67 static int
report_free_dnode_range(struct diffarg * da,uint64_t first,uint64_t last)68 report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
69 {
70 ASSERT(first <= last);
71 if (da->da_ddr.ddr_type != DDR_FREE ||
72 first != da->da_ddr.ddr_last + 1) {
73 if (write_record(da) != 0)
74 return (da->da_err);
75 da->da_ddr.ddr_type = DDR_FREE;
76 da->da_ddr.ddr_first = first;
77 da->da_ddr.ddr_last = last;
78 return (0);
79 }
80 da->da_ddr.ddr_last = last;
81 return (0);
82 }
83
84 static int
report_dnode(struct diffarg * da,uint64_t object,dnode_phys_t * dnp)85 report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
86 {
87 ASSERT(dnp != NULL);
88 if (dnp->dn_type == DMU_OT_NONE)
89 return (report_free_dnode_range(da, object, object));
90
91 if (da->da_ddr.ddr_type != DDR_INUSE ||
92 object != da->da_ddr.ddr_last + 1) {
93 if (write_record(da) != 0)
94 return (da->da_err);
95 da->da_ddr.ddr_type = DDR_INUSE;
96 da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
97 return (0);
98 }
99 da->da_ddr.ddr_last = object;
100 return (0);
101 }
102
103 #define DBP_SPAN(dnp, level) \
104 (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
105 (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
106
107 /* ARGSUSED */
108 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)109 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
110 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
111 {
112 struct diffarg *da = arg;
113 int err = 0;
114
115 if (issig(JUSTLOOKING) && issig(FORREAL))
116 return (SET_ERROR(EINTR));
117
118 if (bp == NULL || zb->zb_object != DMU_META_DNODE_OBJECT)
119 return (0);
120
121 if (BP_IS_HOLE(bp)) {
122 uint64_t span = DBP_SPAN(dnp, zb->zb_level);
123 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
124
125 err = report_free_dnode_range(da, dnobj,
126 dnobj + (span >> DNODE_SHIFT) - 1);
127 if (err)
128 return (err);
129 } else if (zb->zb_level == 0) {
130 dnode_phys_t *blk;
131 arc_buf_t *abuf;
132 arc_flags_t aflags = ARC_FLAG_WAIT;
133 int blksz = BP_GET_LSIZE(bp);
134 int i;
135
136 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
137 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
138 &aflags, zb) != 0)
139 return (SET_ERROR(EIO));
140
141 blk = abuf->b_data;
142 for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
143 uint64_t dnobj = (zb->zb_blkid <<
144 (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
145 err = report_dnode(da, dnobj, blk+i);
146 if (err)
147 break;
148 }
149 (void) arc_buf_remove_ref(abuf, &abuf);
150 if (err)
151 return (err);
152 /* Don't care about the data blocks */
153 return (TRAVERSE_VISIT_NO_CHILDREN);
154 }
155 return (0);
156 }
157
158 int
dmu_diff(const char * tosnap_name,const char * fromsnap_name,struct vnode * vp,offset_t * offp)159 dmu_diff(const char *tosnap_name, const char *fromsnap_name,
160 struct vnode *vp, offset_t *offp)
161 {
162 struct diffarg da;
163 dsl_dataset_t *fromsnap;
164 dsl_dataset_t *tosnap;
165 dsl_pool_t *dp;
166 int error;
167 uint64_t fromtxg;
168
169 if (strchr(tosnap_name, '@') == NULL ||
170 strchr(fromsnap_name, '@') == NULL)
171 return (SET_ERROR(EINVAL));
172
173 error = dsl_pool_hold(tosnap_name, FTAG, &dp);
174 if (error != 0)
175 return (error);
176
177 error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
178 if (error != 0) {
179 dsl_pool_rele(dp, FTAG);
180 return (error);
181 }
182
183 error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
184 if (error != 0) {
185 dsl_dataset_rele(tosnap, FTAG);
186 dsl_pool_rele(dp, FTAG);
187 return (error);
188 }
189
190 if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
191 dsl_dataset_rele(fromsnap, FTAG);
192 dsl_dataset_rele(tosnap, FTAG);
193 dsl_pool_rele(dp, FTAG);
194 return (SET_ERROR(EXDEV));
195 }
196
197 fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
198 dsl_dataset_rele(fromsnap, FTAG);
199
200 dsl_dataset_long_hold(tosnap, FTAG);
201 dsl_pool_rele(dp, FTAG);
202
203 da.da_vp = vp;
204 da.da_offp = offp;
205 da.da_ddr.ddr_type = DDR_NONE;
206 da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
207 da.da_err = 0;
208
209 error = traverse_dataset(tosnap, fromtxg,
210 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, diff_cb, &da);
211
212 if (error != 0) {
213 da.da_err = error;
214 } else {
215 /* we set the da.da_err we return as side-effect */
216 (void) write_record(&da);
217 }
218
219 dsl_dataset_long_rele(tosnap, FTAG);
220 dsl_dataset_rele(tosnap, FTAG);
221
222 return (da.da_err);
223 }
224