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 */
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 file *da_fp; /* 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 kthread_t *da_td;
49 };
50
51 static int
write_bytes(struct diffarg * da)52 write_bytes(struct diffarg *da)
53 {
54 struct uio auio;
55 struct iovec aiov;
56
57 aiov.iov_base = (caddr_t)&da->da_ddr;
58 aiov.iov_len = sizeof (da->da_ddr);
59 auio.uio_iov = &aiov;
60 auio.uio_iovcnt = 1;
61 auio.uio_resid = aiov.iov_len;
62 auio.uio_segflg = UIO_SYSSPACE;
63 auio.uio_rw = UIO_WRITE;
64 auio.uio_offset = (off_t)-1;
65 auio.uio_td = da->da_td;
66 #ifdef _KERNEL
67 if (da->da_fp->f_type == DTYPE_VNODE)
68 bwillwrite();
69 return (fo_write(da->da_fp, &auio, da->da_td->td_ucred, 0, da->da_td));
70 #else
71 fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
72 return (EOPNOTSUPP);
73 #endif
74 }
75
76 static int
write_record(struct diffarg * da)77 write_record(struct diffarg *da)
78 {
79
80 if (da->da_ddr.ddr_type == DDR_NONE) {
81 da->da_err = 0;
82 return (0);
83 }
84
85 da->da_err = write_bytes(da);
86 *da->da_offp += sizeof (da->da_ddr);
87 return (da->da_err);
88 }
89
90 static int
report_free_dnode_range(struct diffarg * da,uint64_t first,uint64_t last)91 report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
92 {
93 ASSERT(first <= last);
94 if (da->da_ddr.ddr_type != DDR_FREE ||
95 first != da->da_ddr.ddr_last + 1) {
96 if (write_record(da) != 0)
97 return (da->da_err);
98 da->da_ddr.ddr_type = DDR_FREE;
99 da->da_ddr.ddr_first = first;
100 da->da_ddr.ddr_last = last;
101 return (0);
102 }
103 da->da_ddr.ddr_last = last;
104 return (0);
105 }
106
107 static int
report_dnode(struct diffarg * da,uint64_t object,dnode_phys_t * dnp)108 report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
109 {
110 ASSERT(dnp != NULL);
111 if (dnp->dn_type == DMU_OT_NONE)
112 return (report_free_dnode_range(da, object, object));
113
114 if (da->da_ddr.ddr_type != DDR_INUSE ||
115 object != da->da_ddr.ddr_last + 1) {
116 if (write_record(da) != 0)
117 return (da->da_err);
118 da->da_ddr.ddr_type = DDR_INUSE;
119 da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
120 return (0);
121 }
122 da->da_ddr.ddr_last = object;
123 return (0);
124 }
125
126 #define DBP_SPAN(dnp, level) \
127 (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
128 (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
129
130 /* ARGSUSED */
131 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)132 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
133 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
134 {
135 struct diffarg *da = arg;
136 int err = 0;
137
138 if (issig(JUSTLOOKING) && issig(FORREAL))
139 return (SET_ERROR(EINTR));
140
141 if (bp == NULL || zb->zb_object != DMU_META_DNODE_OBJECT)
142 return (0);
143
144 if (BP_IS_HOLE(bp)) {
145 uint64_t span = DBP_SPAN(dnp, zb->zb_level);
146 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
147
148 err = report_free_dnode_range(da, dnobj,
149 dnobj + (span >> DNODE_SHIFT) - 1);
150 if (err)
151 return (err);
152 } else if (zb->zb_level == 0) {
153 dnode_phys_t *blk;
154 arc_buf_t *abuf;
155 arc_flags_t aflags = ARC_FLAG_WAIT;
156 int blksz = BP_GET_LSIZE(bp);
157 int i;
158
159 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
160 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
161 &aflags, zb) != 0)
162 return (SET_ERROR(EIO));
163
164 blk = abuf->b_data;
165 for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
166 uint64_t dnobj = (zb->zb_blkid <<
167 (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
168 err = report_dnode(da, dnobj, blk+i);
169 if (err)
170 break;
171 }
172 arc_buf_destroy(abuf, &abuf);
173 if (err)
174 return (err);
175 /* Don't care about the data blocks */
176 return (TRAVERSE_VISIT_NO_CHILDREN);
177 }
178 return (0);
179 }
180
181 int
dmu_diff(const char * tosnap_name,const char * fromsnap_name,struct vnode * vp,offset_t * offp)182 dmu_diff(const char *tosnap_name, const char *fromsnap_name,
183 #ifdef illumos
184 struct vnode *vp, offset_t *offp)
185 #else
186 struct file *fp, offset_t *offp)
187 #endif
188 {
189 struct diffarg da;
190 dsl_dataset_t *fromsnap;
191 dsl_dataset_t *tosnap;
192 dsl_pool_t *dp;
193 int error;
194 uint64_t fromtxg;
195
196 if (strchr(tosnap_name, '@') == NULL ||
197 strchr(fromsnap_name, '@') == NULL)
198 return (SET_ERROR(EINVAL));
199
200 error = dsl_pool_hold(tosnap_name, FTAG, &dp);
201 if (error != 0)
202 return (error);
203
204 error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
205 if (error != 0) {
206 dsl_pool_rele(dp, FTAG);
207 return (error);
208 }
209
210 error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
211 if (error != 0) {
212 dsl_dataset_rele(tosnap, FTAG);
213 dsl_pool_rele(dp, FTAG);
214 return (error);
215 }
216
217 if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
218 dsl_dataset_rele(fromsnap, FTAG);
219 dsl_dataset_rele(tosnap, FTAG);
220 dsl_pool_rele(dp, FTAG);
221 return (SET_ERROR(EXDEV));
222 }
223
224 fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
225 dsl_dataset_rele(fromsnap, FTAG);
226
227 dsl_dataset_long_hold(tosnap, FTAG);
228 dsl_pool_rele(dp, FTAG);
229
230 da.da_fp = fp;
231 da.da_offp = offp;
232 da.da_ddr.ddr_type = DDR_NONE;
233 da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
234 da.da_err = 0;
235 da.da_td = curthread;
236
237 error = traverse_dataset(tosnap, fromtxg,
238 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, diff_cb, &da);
239
240 if (error != 0) {
241 da.da_err = error;
242 } else {
243 /* we set the da.da_err we return as side-effect */
244 (void) write_record(&da);
245 }
246
247 dsl_dataset_long_rele(tosnap, FTAG);
248 dsl_dataset_rele(tosnap, FTAG);
249
250 return (da.da_err);
251 }
252