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 #ifdef __FreeBSD__
45 kthread_t *da_td;
46 #endif
47 struct file *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 };
52
53 static int
write_bytes(struct diffarg * da)54 write_bytes(struct diffarg *da)
55 {
56 struct uio auio;
57 struct iovec aiov;
58
59 aiov.iov_base = (caddr_t)&da->da_ddr;
60 aiov.iov_len = sizeof (da->da_ddr);
61 auio.uio_iov = &aiov;
62 auio.uio_iovcnt = 1;
63 auio.uio_resid = aiov.iov_len;
64 auio.uio_rw = UIO_WRITE;
65 auio.uio_offset = (off_t)-1;
66 #ifdef __FreeBSD__
67 auio.uio_segflg = UIO_SYSSPACE;
68 auio.uio_td = da->da_td;
69 #else
70 #ifdef _KERNEL
71 auio.uio_vmspace = vmspace_kernel();
72 #endif
73 #endif /* __FreeBSD__ */
74 #ifdef _KERNEL
75 #ifdef __FreeBSD__
76 if (da->da_fp->f_type == DTYPE_VNODE)
77 bwillwrite();
78 return (fo_write(da->da_fp, &auio, da->da_td->td_ucred, 0, da->da_td));
79 #else
80 int flags = 0;
81
82 if (da->da_fp->f_type == DTYPE_VNODE)
83 flags |= FOF_UPDATE_OFFSET;
84 return (*da->da_fp->f_ops->fo_write)(da->da_fp, &da->da_fp->f_offset,
85 &auio, da->da_fp->f_cred, flags);
86 #endif /* __FreeBSD__ */
87 #else
88 fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
89 return (EOPNOTSUPP);
90 #endif
91 }
92
93 static int
write_record(struct diffarg * da)94 write_record(struct diffarg *da)
95 {
96 ssize_t resid; /* have to get resid to get detailed errno */
97
98 if (da->da_ddr.ddr_type == DDR_NONE) {
99 da->da_err = 0;
100 return (0);
101 }
102
103 da->da_err = write_bytes(da);
104 *da->da_offp += sizeof (da->da_ddr);
105 return (da->da_err);
106 }
107
108 static int
report_free_dnode_range(struct diffarg * da,uint64_t first,uint64_t last)109 report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
110 {
111 ASSERT(first <= last);
112 if (da->da_ddr.ddr_type != DDR_FREE ||
113 first != da->da_ddr.ddr_last + 1) {
114 if (write_record(da) != 0)
115 return (da->da_err);
116 da->da_ddr.ddr_type = DDR_FREE;
117 da->da_ddr.ddr_first = first;
118 da->da_ddr.ddr_last = last;
119 return (0);
120 }
121 da->da_ddr.ddr_last = last;
122 return (0);
123 }
124
125 static int
report_dnode(struct diffarg * da,uint64_t object,dnode_phys_t * dnp)126 report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
127 {
128 ASSERT(dnp != NULL);
129 if (dnp->dn_type == DMU_OT_NONE)
130 return (report_free_dnode_range(da, object, object));
131
132 if (da->da_ddr.ddr_type != DDR_INUSE ||
133 object != da->da_ddr.ddr_last + 1) {
134 if (write_record(da) != 0)
135 return (da->da_err);
136 da->da_ddr.ddr_type = DDR_INUSE;
137 da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
138 return (0);
139 }
140 da->da_ddr.ddr_last = object;
141 return (0);
142 }
143
144 #define DBP_SPAN(dnp, level) \
145 (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
146 (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
147
148 /* ARGSUSED */
149 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)150 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
151 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
152 {
153 struct diffarg *da = arg;
154 int err = 0;
155
156 if (issig(JUSTLOOKING) && issig(FORREAL))
157 return (SET_ERROR(EINTR));
158
159 if (bp == NULL || zb->zb_object != DMU_META_DNODE_OBJECT)
160 return (0);
161
162 if (BP_IS_HOLE(bp)) {
163 uint64_t span = DBP_SPAN(dnp, zb->zb_level);
164 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
165
166 err = report_free_dnode_range(da, dnobj,
167 dnobj + (span >> DNODE_SHIFT) - 1);
168 if (err)
169 return (err);
170 } else if (zb->zb_level == 0) {
171 dnode_phys_t *blk;
172 arc_buf_t *abuf;
173 arc_flags_t aflags = ARC_FLAG_WAIT;
174 int blksz = BP_GET_LSIZE(bp);
175 int i;
176
177 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
178 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
179 &aflags, zb) != 0)
180 return (SET_ERROR(EIO));
181
182 blk = abuf->b_data;
183 for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
184 uint64_t dnobj = (zb->zb_blkid <<
185 (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
186 err = report_dnode(da, dnobj, blk+i);
187 if (err)
188 break;
189 }
190 arc_buf_destroy(abuf, &abuf);
191 if (err)
192 return (err);
193 /* Don't care about the data blocks */
194 return (TRAVERSE_VISIT_NO_CHILDREN);
195 }
196 return (0);
197 }
198
199 int
dmu_diff(const char * tosnap_name,const char * fromsnap_name,struct file * fp,offset_t * offp)200 dmu_diff(const char *tosnap_name, const char *fromsnap_name,
201 struct file *fp, offset_t *offp)
202 {
203 struct diffarg da;
204 dsl_dataset_t *fromsnap;
205 dsl_dataset_t *tosnap;
206 dsl_pool_t *dp;
207 int error;
208 uint64_t fromtxg;
209
210 if (strchr(tosnap_name, '@') == NULL ||
211 strchr(fromsnap_name, '@') == NULL)
212 return (SET_ERROR(EINVAL));
213
214 error = dsl_pool_hold(tosnap_name, FTAG, &dp);
215 if (error != 0)
216 return (error);
217
218 error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
219 if (error != 0) {
220 dsl_pool_rele(dp, FTAG);
221 return (error);
222 }
223
224 error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
225 if (error != 0) {
226 dsl_dataset_rele(tosnap, FTAG);
227 dsl_pool_rele(dp, FTAG);
228 return (error);
229 }
230
231 if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
232 dsl_dataset_rele(fromsnap, FTAG);
233 dsl_dataset_rele(tosnap, FTAG);
234 dsl_pool_rele(dp, FTAG);
235 return (SET_ERROR(EXDEV));
236 }
237
238 fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
239 dsl_dataset_rele(fromsnap, FTAG);
240
241 dsl_dataset_long_hold(tosnap, FTAG);
242 dsl_pool_rele(dp, FTAG);
243
244 #ifdef __FreeBSD__
245 da.da_td = curthread;
246 #endif
247 da.da_fp = fp;
248 da.da_offp = offp;
249 da.da_ddr.ddr_type = DDR_NONE;
250 da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
251 da.da_err = 0;
252
253 error = traverse_dataset(tosnap, fromtxg,
254 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, diff_cb, &da);
255
256 if (error != 0) {
257 da.da_err = error;
258 } else {
259 /* we set the da.da_err we return as side-effect */
260 (void) write_record(&da);
261 }
262
263 dsl_dataset_long_rele(tosnap, FTAG);
264 dsl_dataset_rele(tosnap, FTAG);
265
266 return (da.da_err);
267 }
268