handle resync completion
[thirdparty/mdadm.git] / monitor.c
CommitLineData
549e9569
NB
1
2#include "mdadm.h"
3#include "mdmon.h"
4
5#include <sys/select.h>
6
7
8static char *array_states[] = {
9 "clear", "inactive", "suspended", "readonly", "read-auto",
10 "clean", "active", "write-pending", "active-idle", NULL };
11static char *sync_actions[] = {
12 "idle", "reshape", "resync", "recover", "check", "repair", NULL
13};
14
15static int write_attr(char *attr, int fd)
16{
17 return write(fd, attr, strlen(attr));
18}
19
20static void add_fd(fd_set *fds, int *maxfd, int fd)
21{
22 if (fd < 0)
23 return;
24 if (fd > *maxfd)
25 *maxfd = fd;
26 FD_SET(fd, fds);
27}
28
29static int read_attr(char *buf, int len, int fd)
30{
31 int n;
32
33 if (fd < 0) {
34 buf[0] = 0;
35 return 0;
36 }
37 lseek(fd, 0, 0);
38 n = read(fd, buf, len - 1);
39
40 if (n <= 0) {
41 buf[0] = 0;
42 return 0;
43 }
44 buf[n] = 0;
45 if (buf[n-1] == '\n')
46 buf[n-1] = 0;
47 return n;
48}
49
50static int get_sync_pos(struct active_array *a)
51{
52 char buf[30];
53 int n;
54
55 n = read_attr(buf, 30, a->sync_pos_fd);
56 if (n <= 0)
57 return n;
58
59 if (strncmp(buf, "max", 3) == 0) {
60 a->sync_pos = ~(unsigned long long)0;
61 return 1;
62 }
63 a->sync_pos = strtoull(buf, NULL, 10);
64 return 1;
65}
66
c052ba30
DW
67static int get_resync_start(struct active_array *a)
68{
69 char buf[30];
70 int n;
71
72 n = read_attr(buf, 30, a->resync_start_fd);
73 if (n <= 0)
74 return n;
75
76 a->resync_start = strtoull(buf, NULL, 10);
77
78 return 1;
79}
549e9569
NB
80
81static int attr_match(const char *attr, const char *str)
82{
83 /* See if attr, read from a sysfs file, matches
84 * str. They must either be the same, or attr can
85 * have a trailing newline or comma
86 */
87 while (*attr && *str && *attr == *str) {
88 attr++;
89 str++;
90 }
91
92 if (*str || (*attr && *attr != ',' && *attr != '\n'))
93 return 0;
94 return 1;
95}
96
97static int match_word(const char *word, char **list)
98{
99 int n;
100 for (n=0; list[n]; n++)
101 if (attr_match(word, list[n]))
102 break;
103 return n;
104}
105
106static enum array_state read_state(int fd)
107{
108 char buf[20];
109 int n = read_attr(buf, 20, fd);
110
111 if (n <= 0)
112 return bad_word;
113 return (enum array_state) match_word(buf, array_states);
114}
115
116static enum sync_action read_action( int fd)
117{
118 char buf[20];
119 int n = read_attr(buf, 20, fd);
120
121 if (n <= 0)
122 return bad_action;
123 return (enum sync_action) match_word(buf, sync_actions);
124}
125
126#define DS_FAULTY 1
127#define DS_INSYNC 2
128#define DS_WRITE_MOSTLY 4
129#define DS_SPARE 8
130#define DS_REMOVE 1024
131
132int read_dev_state(int fd)
133{
134 char buf[60];
135 int n = read_attr(buf, 60, fd);
136 char *cp;
137 int rv = 0;
138
139 if (n <= 0)
140 return 0;
141
142 cp = buf;
143 while (cp) {
144 if (attr_match("faulty", cp))
145 rv |= DS_FAULTY;
146 if (attr_match("in_sync", cp))
147 rv |= DS_INSYNC;
148 if (attr_match("write_mostly", cp))
149 rv |= DS_WRITE_MOSTLY;
150 if (attr_match("spare", cp))
151 rv |= DS_SPARE;
152 cp = strchr(cp, ',');
153 if (cp)
154 cp++;
155 }
156 return rv;
157}
158
159
160/* Monitor a set of active md arrays - all of which share the
161 * same metadata - and respond to events that require
162 * metadata update.
163 *
164 * New arrays are detected by another thread which allocates
165 * required memory and attaches the data structure to our list.
166 *
167 * Events:
168 * Array stops.
169 * This is detected by array_state going to 'clear' or 'inactive'.
170 * while we thought it was active.
171 * Response is to mark metadata as clean and 'clear' the array(??)
172 * write-pending
173 * array_state if 'write-pending'
174 * We mark metadata as 'dirty' then set array to 'active'.
175 * active_idle
176 * Either ignore, or mark clean, then mark metadata as clean.
177 *
178 * device fails
179 * detected by rd-N/state reporting "faulty"
180 * mark device as 'failed' in metadata, the remove device
181 * by writing 'remove' to rd/state.
182 *
183 * sync completes
184 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
185 * MaxSector
186 * Notify metadata that sync is complete.
187 * "Deal with Degraded"
188 *
189 * recovery completes
190 * sync_action changes from 'recover' to 'idle'
191 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
192 * "Deal with Degraded"
193 *
194 * deal with degraded array
195 * We only do this when first noticing the array is degraded.
196 * This can be when we first see the array, when sync completes or
197 * when recovery completes.
198 *
199 * Check if number of failed devices suggests recovery is needed, and
200 * skip if not.
201 * Ask metadata for a spare device
202 * Add device as not in_sync and give a role
203 * Update metadata.
204 * Start recovery.
205 *
206 * deal with resync
c052ba30
DW
207 * This only happens on finding a new array... mdadm will have set
208 * 'resync_start' to the correct value. If 'resync_start' indicates that an
209 * resync needs to occur set the array to the 'active' state rather than the
210 * initial read-auto state.
549e9569
NB
211 *
212 *
213 *
214 * We wait for a change (poll/select) on array_state, sync_action, and
215 * each rd-X/state file.
216 * When we get any change, we check everything. So read each state file,
217 * then decide what to do.
218 *
219 * The core action is to write new metadata to all devices in the array.
220 * This is done at most once on any wakeup.
221 * After that we might:
222 * - update the array_state
223 * - set the role of some devices.
224 * - request a sync_action
225 *
226 */
227
228static int read_and_act(struct active_array *a)
229{
230 int check_degraded;
231 struct mdinfo *mdi;
232
233 a->next_state = bad_word;
234 a->next_action = bad_action;
235
236 a->curr_state = read_state(a->info.state_fd);
237 a->curr_action = read_action(a->action_fd);
238 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
239 mdi->next_state = 0;
240 mdi->curr_state = read_dev_state(mdi->state_fd);
241 }
242
243 if (a->curr_state <= inactive &&
244 a->prev_state > inactive) {
245 /* array has been stopped */
246 get_sync_pos(a);
247 a->container->ss->mark_clean(a, a->sync_pos);
248 a->next_state = clear;
249 }
250 if (a->curr_state == write_pending) {
251 a->container->ss->mark_dirty(a);
252 a->next_state = active;
253 }
254 if (a->curr_state == active_idle) {
255 /* Set array to 'clean' FIRST, then
256 * a->ss->mark_clean(a);
257 * just ignore for now.
258 */
259 }
260
261 if (a->curr_state == readonly) {
262 /* Well, I'm ready to handle things, so
263 * read-auto is OK. FIXME what if we really want
264 * readonly ???
265 */
c052ba30
DW
266 get_resync_start(a);
267 if (a->resync_start == ~0ULL)
268 a->next_state = read_auto; /* array is clean */
269 else {
270 a->container->ss->mark_dirty(a);
271 a->next_state = active;
272 }
549e9569
NB
273 }
274
275 if (a->curr_action == idle &&
276 a->prev_action == resync) {
fd7cde1b
DW
277 /* check resync_start to see if it is 'max' */
278 get_resync_start(a);
279 a->container->ss->mark_sync(a, a->resync_start);
549e9569
NB
280 check_degraded = 1;
281 }
282
283 if (a->curr_action == idle &&
284 a->prev_action == recover) {
285 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
286 a->container->ss->set_disk(a, mdi->disk.raid_disk);
287 if (! (mdi->curr_state & DS_INSYNC))
288 check_degraded = 1;
289 }
290 }
291
292
293 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
294 if (mdi->curr_state & DS_FAULTY) {
295 a->container->ss->set_disk(a, mdi->disk.raid_disk);
296 check_degraded = 1;
297 mdi->next_state = DS_REMOVE;
298 }
299 }
300
301 if (check_degraded) {
302 // FIXME;
303 }
304
305 a->container->ss->sync_metadata(a);
306
307 /* Effect state changes in the array */
308 if (a->next_state != bad_word)
309 write_attr(array_states[a->next_state], a->info.state_fd);
310 if (a->next_action != bad_action)
311 write_attr(sync_actions[a->next_action], a->action_fd);
312 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
313 if (mdi->next_state == DS_REMOVE)
314 write_attr("remove", mdi->state_fd);
315 if (mdi->next_state & DS_INSYNC)
316 write_attr("+in_sync", mdi->state_fd);
317 }
318
319 /* move curr_ to prev_ */
320 a->prev_state = a->curr_state;
321
322 a->prev_action = a->curr_action;
323
324 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
325 mdi->prev_state = mdi->curr_state;
326 mdi->next_state = 0;
327 }
328
329 return 1;
330}
331
332static int wait_and_act(struct active_array *aa, int pfd, int nowait)
333{
334 fd_set rfds;
335 int maxfd = 0;
336 struct active_array *a;
337 int rv;
338
339 FD_ZERO(&rfds);
340
341 add_fd(&rfds, &maxfd, pfd);
342 for (a = aa ; a ; a = a->next) {
343 struct mdinfo *mdi;
344
345 add_fd(&rfds, &maxfd, a->info.state_fd);
346 add_fd(&rfds, &maxfd, a->action_fd);
347 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
348 add_fd(&rfds, &maxfd, mdi->state_fd);
349 }
350
351 if (!nowait) {
352 rv = select(maxfd+1, &rfds, NULL, NULL, NULL);
353
354 if (rv <= 0)
355 return rv;
356
357 if (FD_ISSET(pfd, &rfds)) {
358 char buf[4];
359 read(pfd, buf, 4);
360 ; // FIXME read from the pipe
361 }
362 }
363
364 for (a = aa; a ; a = a->next) {
365 if (a->replaces) {
366 struct active_array **ap;
367 for (ap = &a->next; *ap && *ap != a->replaces;
368 ap = & (*ap)->next)
369 ;
370 if (*ap)
371 *ap = (*ap)->next;
372 discard_this = a->replaces;
373 a->replaces = NULL;
374 }
375 rv += read_and_act(a);
376 }
377 return rv;
378}
379
380void do_monitor(struct supertype *container)
381{
382 int rv;
383 int first = 1;
384 do {
385 rv = wait_and_act(container->arrays, container->pipe[0], first);
386 first = 0;
387 } while (rv >= 0);
388}