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.
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.
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]
23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
27 #pragma ident "%Z%%M% %I% %E% SMI"
29 #include <sys/spa_impl.h>
31 #include <sys/dsl_synctask.h>
34 * Routines to manage the on-disk history log.
36 * The history log is stored as a dmu object containing
37 * <packed record length, record nvlist> tuples.
39 * Where "record nvlist" is a nvlist containing uint64_ts and strings, and
40 * "packed record length" is the packed length of the "record nvlist" stored
41 * as a little endian uint64_t.
43 * The log is implemented as a ring buffer, though the original creation
44 * of the pool ('zpool create') is never overwritten.
46 * The history log is tracked as object 'spa_t::spa_history'. The bonus buffer
47 * of 'spa_history' stores the offsets for logging/retrieving history as
48 * 'spa_history_phys_t'. 'sh_pool_create_len' is the ending offset in bytes of
49 * where the 'zpool create' record is stored. This allows us to never
50 * overwrite the original creation of the pool. 'sh_phys_max_off' is the
51 * physical ending offset in bytes of the log. This tells you the length of
52 * the buffer. 'sh_eof' is the logical EOF (in bytes). Whenever a record
53 * is added, 'sh_eof' is incremented by the the size of the record.
54 * 'sh_eof' is never decremented. 'sh_bof' is the logical BOF (in bytes).
55 * This is where the consumer should start reading from after reading in
56 * the 'zpool create' portion of the log.
58 * 'sh_records_lost' keeps track of how many records have been overwritten
59 * and permanently lost.
62 typedef enum history_log_type {
67 typedef struct history_arg {
68 const char *ha_history_str;
69 history_log_type_t ha_log_type;
72 /* convert a logical offset to physical */
74 spa_history_log_to_phys(uint64_t log_off, spa_history_phys_t *shpp)
78 phys_len = shpp->sh_phys_max_off - shpp->sh_pool_create_len;
79 return ((log_off - shpp->sh_pool_create_len) % phys_len
80 + shpp->sh_pool_create_len);
84 spa_history_create_obj(spa_t *spa, dmu_tx_t *tx)
87 spa_history_phys_t *shpp;
88 objset_t *mos = spa->spa_meta_objset;
90 ASSERT(spa->spa_history == 0);
91 spa->spa_history = dmu_object_alloc(mos, DMU_OT_SPA_HISTORY,
92 SPA_MAXBLOCKSIZE, DMU_OT_SPA_HISTORY_OFFSETS,
93 sizeof (spa_history_phys_t), tx);
95 VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT,
96 DMU_POOL_HISTORY, sizeof (uint64_t), 1,
97 &spa->spa_history, tx) == 0);
99 VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp));
100 ASSERT(dbp->db_size >= sizeof (spa_history_phys_t));
103 dmu_buf_will_dirty(dbp, tx);
106 * Figure out maximum size of history log. We set it at
107 * 1% of pool size, with a max of 32MB and min of 128KB.
109 shpp->sh_phys_max_off = spa_get_dspace(spa) / 100;
110 shpp->sh_phys_max_off = MIN(shpp->sh_phys_max_off, 32<<20);
111 shpp->sh_phys_max_off = MAX(shpp->sh_phys_max_off, 128<<10);
113 dmu_buf_rele(dbp, FTAG);
117 * Change 'sh_bof' to the beginning of the next record.
120 spa_history_advance_bof(spa_t *spa, spa_history_phys_t *shpp)
122 objset_t *mos = spa->spa_meta_objset;
123 uint64_t firstread, reclen, phys_bof;
124 char buf[sizeof (reclen)];
127 phys_bof = spa_history_log_to_phys(shpp->sh_bof, shpp);
128 firstread = MIN(sizeof (reclen), shpp->sh_phys_max_off - phys_bof);
130 if ((err = dmu_read(mos, spa->spa_history, phys_bof, firstread,
133 if (firstread != sizeof (reclen)) {
134 if ((err = dmu_read(mos, spa->spa_history,
135 shpp->sh_pool_create_len, sizeof (reclen) - firstread,
136 buf + firstread)) != 0)
140 reclen = LE_64(*((uint64_t *)buf));
141 shpp->sh_bof += reclen + sizeof (reclen);
142 shpp->sh_records_lost++;
147 spa_history_write(spa_t *spa, void *buf, uint64_t len, spa_history_phys_t *shpp,
150 uint64_t firstwrite, phys_eof;
151 objset_t *mos = spa->spa_meta_objset;
154 ASSERT(MUTEX_HELD(&spa->spa_history_lock));
156 /* see if we need to reset logical BOF */
157 while (shpp->sh_phys_max_off - shpp->sh_pool_create_len -
158 (shpp->sh_eof - shpp->sh_bof) <= len) {
159 if ((err = spa_history_advance_bof(spa, shpp)) != 0)
163 phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp);
164 firstwrite = MIN(len, shpp->sh_phys_max_off - phys_eof);
166 dmu_write(mos, spa->spa_history, phys_eof, firstwrite, buf, tx);
170 /* write out the rest at the beginning of physical file */
171 dmu_write(mos, spa->spa_history, shpp->sh_pool_create_len,
172 len, (char *)buf + firstwrite, tx);
179 * Write out a history event.
182 spa_history_log_sync(void *arg1, void *arg2, dmu_tx_t *tx)
185 history_arg_t *hap = arg2;
186 const char *history_str = hap->ha_history_str;
187 objset_t *mos = spa->spa_meta_objset;
189 spa_history_phys_t *shpp;
193 char *record_packed = NULL;
196 if (history_str == NULL)
200 * If we have an older pool that doesn't have a command
201 * history object, create it now.
203 mutex_enter(&spa->spa_history_lock);
204 if (!spa->spa_history)
205 spa_history_create_obj(spa, tx);
206 mutex_exit(&spa->spa_history_lock);
209 * Get the offset of where we need to write via the bonus buffer.
210 * Update the offset when the write completes.
212 VERIFY(0 == dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp));
215 dmu_buf_will_dirty(dbp, tx);
219 dmu_object_info_t doi;
220 dmu_object_info_from_db(dbp, &doi);
221 ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS);
225 /* construct a nvlist of the current time and cmd string */
226 VERIFY(nvlist_alloc(&nvrecord, NV_UNIQUE_NAME, KM_SLEEP) == 0);
227 VERIFY(nvlist_add_uint64(nvrecord, ZPOOL_HIST_TIME,
228 gethrestime_sec()) == 0);
229 VERIFY(nvlist_add_string(nvrecord, ZPOOL_HIST_CMD, history_str) == 0);
230 VERIFY(nvlist_pack(nvrecord, &record_packed, &reclen,
231 NV_ENCODE_XDR, KM_SLEEP) == 0);
233 mutex_enter(&spa->spa_history_lock);
234 if (hap->ha_log_type == LOG_CMD_CREATE)
235 VERIFY(shpp->sh_eof == shpp->sh_pool_create_len);
237 /* write out the packed length as little endian */
238 le_len = LE_64((uint64_t)reclen);
239 ret = spa_history_write(spa, &le_len, sizeof (le_len), shpp, tx);
241 ret = spa_history_write(spa, record_packed, reclen, shpp, tx);
243 if (!ret && hap->ha_log_type == LOG_CMD_CREATE) {
244 shpp->sh_pool_create_len += sizeof (le_len) + reclen;
245 shpp->sh_bof = shpp->sh_pool_create_len;
248 mutex_exit(&spa->spa_history_lock);
249 nvlist_free(nvrecord);
250 kmem_free(record_packed, reclen);
251 dmu_buf_rele(dbp, FTAG);
255 * Write out a history event.
258 spa_history_log(spa_t *spa, const char *history_str, uint64_t pool_create)
262 ha.ha_history_str = history_str;
263 ha.ha_log_type = pool_create ? LOG_CMD_CREATE : LOG_CMD_NO_CREATE;
264 return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_history_log_sync,
269 * Read out the command history.
272 spa_history_get(spa_t *spa, uint64_t *offp, uint64_t *len, char *buf)
274 objset_t *mos = spa->spa_meta_objset;
276 uint64_t read_len, phys_read_off, phys_eof;
277 uint64_t leftover = 0;
278 spa_history_phys_t *shpp;
282 * If the command history doesn't exist (older pool),
283 * that's ok, just return ENOENT.
285 if (!spa->spa_history)
288 if ((err = dmu_bonus_hold(mos, spa->spa_history, FTAG, &dbp)) != 0)
294 dmu_object_info_t doi;
295 dmu_object_info_from_db(dbp, &doi);
296 ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_SPA_HISTORY_OFFSETS);
300 mutex_enter(&spa->spa_history_lock);
301 phys_eof = spa_history_log_to_phys(shpp->sh_eof, shpp);
303 if (*offp < shpp->sh_pool_create_len) {
304 /* read in just the zpool create history */
305 phys_read_off = *offp;
306 read_len = MIN(*len, shpp->sh_pool_create_len -
310 * Need to reset passed in offset to BOF if the passed in
311 * offset has since been overwritten.
313 *offp = MAX(*offp, shpp->sh_bof);
314 phys_read_off = spa_history_log_to_phys(*offp, shpp);
317 * Read up to the minimum of what the user passed down or
318 * the EOF (physical or logical). If we hit physical EOF,
319 * use 'leftover' to read from the physical BOF.
321 if (phys_read_off <= phys_eof) {
322 read_len = MIN(*len, phys_eof - phys_read_off);
325 shpp->sh_phys_max_off - phys_read_off);
326 if (phys_read_off + *len > shpp->sh_phys_max_off) {
327 leftover = MIN(*len - read_len,
328 phys_eof - shpp->sh_pool_create_len);
333 /* offset for consumer to use next */
334 *offp += read_len + leftover;
336 /* tell the consumer how much you actually read */
337 *len = read_len + leftover;
340 mutex_exit(&spa->spa_history_lock);
341 dmu_buf_rele(dbp, FTAG);
345 err = dmu_read(mos, spa->spa_history, phys_read_off, read_len, buf);
346 if (leftover && err == 0) {
347 err = dmu_read(mos, spa->spa_history, shpp->sh_pool_create_len,
348 leftover, buf + read_len);
350 mutex_exit(&spa->spa_history_lock);
352 dmu_buf_rele(dbp, FTAG);