xref: /freebsd/sbin/hastd/metadata.c (revision f5147e312f43a9050468de539aeafa072caa1a60)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009-2010 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Pawel Jakub Dawidek under sponsorship from
8  * the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <string.h>
38 #include <strings.h>
39 #include <unistd.h>
40 
41 #include <ebuf.h>
42 #include <nv.h>
43 #include <pjdlog.h>
44 #include <subr.h>
45 
46 #include "metadata.h"
47 
48 int
49 metadata_read(struct hast_resource *res, bool openrw)
50 {
51 	unsigned char *buf;
52 	struct ebuf *eb;
53 	struct nv *nv;
54 	ssize_t done;
55 	const char *str;
56 	int rerrno;
57 	bool opened_here;
58 
59 	opened_here = false;
60 	rerrno = 0;
61 
62 	/*
63 	 * Is this first metadata_read() call for this resource?
64 	 */
65 	if (res->hr_localfd == -1) {
66 		if (provinfo(res, openrw) == -1) {
67 			rerrno = errno;
68 			goto fail;
69 		}
70 		opened_here = true;
71 		pjdlog_debug(1, "Obtained info about %s.", res->hr_localpath);
72 		if (openrw) {
73 			if (flock(res->hr_localfd, LOCK_EX | LOCK_NB) == -1) {
74 				rerrno = errno;
75 				if (errno == EOPNOTSUPP) {
76 					pjdlog_warning("Unable to lock %s (operation not supported), but continuing.",
77 					    res->hr_localpath);
78 				} else {
79 					pjdlog_errno(LOG_ERR,
80 					    "Unable to lock %s",
81 					    res->hr_localpath);
82 					goto fail;
83 				}
84 			}
85 			pjdlog_debug(1, "Locked %s.", res->hr_localpath);
86 		}
87 	}
88 
89 	eb = ebuf_alloc(METADATA_SIZE);
90 	if (eb == NULL) {
91 		rerrno = errno;
92 		pjdlog_errno(LOG_ERR,
93 		    "Unable to allocate memory to read metadata");
94 		goto fail;
95 	}
96 	if (ebuf_add_tail(eb, NULL, METADATA_SIZE) == -1) {
97 		rerrno = errno;
98 		pjdlog_errno(LOG_ERR,
99 		    "Unable to allocate memory to read metadata");
100 		ebuf_free(eb);
101 		goto fail;
102 	}
103 	buf = ebuf_data(eb, NULL);
104 	PJDLOG_ASSERT(buf != NULL);
105 	done = pread(res->hr_localfd, buf, METADATA_SIZE, 0);
106 	if (done == -1 || done != METADATA_SIZE) {
107 		rerrno = errno;
108 		pjdlog_errno(LOG_ERR, "Unable to read metadata");
109 		ebuf_free(eb);
110 		goto fail;
111 	}
112 	nv = nv_ntoh(eb);
113 	if (nv == NULL) {
114 		rerrno = errno;
115 		pjdlog_errno(LOG_ERR, "Metadata read from %s is invalid",
116 		    res->hr_localpath);
117 		ebuf_free(eb);
118 		goto fail;
119 	}
120 
121 	str = nv_get_string(nv, "resource");
122 	if (str != NULL && strcmp(str, res->hr_name) != 0) {
123 		pjdlog_error("Provider %s is not part of resource %s.",
124 		    res->hr_localpath, res->hr_name);
125 		nv_free(nv);
126 		goto fail;
127 	}
128 
129 	res->hr_datasize = nv_get_uint64(nv, "datasize");
130 	res->hr_extentsize = (int)nv_get_uint32(nv, "extentsize");
131 	res->hr_keepdirty = (int)nv_get_uint32(nv, "keepdirty");
132 	res->hr_localoff = nv_get_uint64(nv, "offset");
133 	res->hr_resuid = nv_get_uint64(nv, "resuid");
134 	if (res->hr_role != HAST_ROLE_PRIMARY) {
135 		/* Secondary or init role. */
136 		res->hr_secondary_localcnt = nv_get_uint64(nv, "localcnt");
137 		res->hr_secondary_remotecnt = nv_get_uint64(nv, "remotecnt");
138 	}
139 	if (res->hr_role != HAST_ROLE_SECONDARY) {
140 		/* Primary or init role. */
141 		res->hr_primary_localcnt = nv_get_uint64(nv, "localcnt");
142 		res->hr_primary_remotecnt = nv_get_uint64(nv, "remotecnt");
143 	}
144 	str = nv_get_string(nv, "prevrole");
145 	if (str != NULL) {
146 		if (strcmp(str, "primary") == 0)
147 			res->hr_previous_role = HAST_ROLE_PRIMARY;
148 		else if (strcmp(str, "secondary") == 0)
149 			res->hr_previous_role = HAST_ROLE_SECONDARY;
150 	}
151 
152 	if (nv_error(nv) != 0) {
153 		errno = rerrno = nv_error(nv);
154 		pjdlog_errno(LOG_ERR, "Unable to read metadata from %s",
155 		    res->hr_localpath);
156 		nv_free(nv);
157 		goto fail;
158 	}
159 	nv_free(nv);
160 	return (0);
161 fail:
162 	if (opened_here) {
163 		close(res->hr_localfd);
164 		res->hr_localfd = -1;
165 	}
166 	errno = rerrno;
167 	return (-1);
168 }
169 
170 int
171 metadata_write(struct hast_resource *res)
172 {
173 	struct ebuf *eb;
174 	struct nv *nv;
175 	unsigned char *buf, *ptr;
176 	size_t size;
177 	ssize_t done;
178 	int ret;
179 
180 	buf = calloc(1, METADATA_SIZE);
181 	if (buf == NULL) {
182 		pjdlog_error("Unable to allocate %zu bytes for metadata.",
183 		    (size_t)METADATA_SIZE);
184 		return (-1);
185 	}
186 
187 	ret = -1;
188 
189 	nv = nv_alloc();
190 	nv_add_string(nv, res->hr_name, "resource");
191 	nv_add_uint64(nv, (uint64_t)res->hr_datasize, "datasize");
192 	nv_add_uint32(nv, (uint32_t)res->hr_extentsize, "extentsize");
193 	nv_add_uint32(nv, (uint32_t)res->hr_keepdirty, "keepdirty");
194 	nv_add_uint64(nv, (uint64_t)res->hr_localoff, "offset");
195 	nv_add_uint64(nv, res->hr_resuid, "resuid");
196 	if (res->hr_role == HAST_ROLE_PRIMARY ||
197 	    res->hr_role == HAST_ROLE_INIT) {
198 		nv_add_uint64(nv, res->hr_primary_localcnt, "localcnt");
199 		nv_add_uint64(nv, res->hr_primary_remotecnt, "remotecnt");
200 	} else /* if (res->hr_role == HAST_ROLE_SECONDARY) */ {
201 		PJDLOG_ASSERT(res->hr_role == HAST_ROLE_SECONDARY);
202 		nv_add_uint64(nv, res->hr_secondary_localcnt, "localcnt");
203 		nv_add_uint64(nv, res->hr_secondary_remotecnt, "remotecnt");
204 	}
205 	nv_add_string(nv, role2str(res->hr_role), "prevrole");
206 	if (nv_error(nv) != 0) {
207 		pjdlog_error("Unable to create metadata.");
208 		goto end;
209 	}
210 	res->hr_previous_role = res->hr_role;
211 	eb = nv_hton(nv);
212 	PJDLOG_ASSERT(eb != NULL);
213 	ptr = ebuf_data(eb, &size);
214 	PJDLOG_ASSERT(ptr != NULL);
215 	PJDLOG_ASSERT(size < METADATA_SIZE);
216 	bcopy(ptr, buf, size);
217 	done = pwrite(res->hr_localfd, buf, METADATA_SIZE, 0);
218 	if (done == -1 || done != METADATA_SIZE) {
219 		pjdlog_errno(LOG_ERR, "Unable to write metadata");
220 		goto end;
221 	}
222 	ret = 0;
223 end:
224 	free(buf);
225 	nv_free(nv);
226 	return (ret);
227 }
228