summaryrefslogtreecommitdiff
path: root/fs/ceph/mdsmap.c
blob: fae97c25ce58d5b268b7e3d73c5d4c94def4946d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>

#include <linux/bug.h>
#include <linux/err.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>

#include "mdsmap.h"
#include "mds_client.h"
#include "super.h"

#define CEPH_MDS_IS_READY(i, ignore_laggy) \
	(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)

static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
{
	int n = 0;
	int i, j;

	/* count */
	for (i = 0; i < m->possible_max_rank; i++)
		if (CEPH_MDS_IS_READY(i, ignore_laggy))
			n++;
	if (n == 0)
		return -1;

	/* pick */
	n = get_random_u32_below(n);
	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
		if (CEPH_MDS_IS_READY(i, ignore_laggy))
			j++;
		if (j > n)
			break;
	}

	return i;
}

/*
 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
 */
int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
{
	int mds;

	mds = __mdsmap_get_random_mds(m, false);
	if (mds == m->possible_max_rank || mds == -1)
		mds = __mdsmap_get_random_mds(m, true);

	return mds == m->possible_max_rank ? -1 : mds;
}

#define __decode_and_drop_type(p, end, type, bad)		\
	do {							\
		if (*p + sizeof(type) > end)			\
			goto bad;				\
		*p += sizeof(type);				\
	} while (0)

#define __decode_and_drop_set(p, end, type, bad)		\
	do {							\
		u32 n;						\
		size_t need;					\
		ceph_decode_32_safe(p, end, n, bad);		\
		need = sizeof(type) * n;			\
		ceph_decode_need(p, end, need, bad);		\
		*p += need;					\
	} while (0)

#define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
	do {							\
		u32 n;						\
		size_t need;					\
		ceph_decode_32_safe(p, end, n, bad);		\
		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
		ceph_decode_need(p, end, need, bad);		\
		*p += need;					\
	} while (0)


static int __decode_and_drop_compat_set(void **p, void* end)
{
	int i;
	/* compat, ro_compat, incompat*/
	for (i = 0; i < 3; i++) {
		u32 n;
		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
		/* mask */
		*p += sizeof(u64);
		/* names (map<u64, string>) */
		n = ceph_decode_32(p);
		while (n-- > 0) {
			u32 len;
			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
					 bad);
			*p += sizeof(u64);
			len = ceph_decode_32(p);
			ceph_decode_need(p, end, len, bad);
			*p += len;
		}
	}
	return 0;
bad:
	return -1;
}

/*
 * Decode an MDS map
 *
 * Ignore any fields we don't care about (there are quite a few of
 * them).
 */
struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
				       void *end, bool msgr2)
{
	struct ceph_client *cl = mdsc->fsc->client;
	struct ceph_mdsmap *m;
	const void *start = *p;
	int i, j, n;
	int err;
	u8 mdsmap_v;
	u16 mdsmap_ev;
	u32 target;

	m = kzalloc(sizeof(*m), GFP_NOFS);
	if (!m)
		return ERR_PTR(-ENOMEM);

	ceph_decode_need(p, end, 1 + 1, bad);
	mdsmap_v = ceph_decode_8(p);
	*p += sizeof(u8);			/* mdsmap_cv */
	if (mdsmap_v >= 4) {
	       u32 mdsmap_len;
	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
	       if (end < *p + mdsmap_len)
		       goto bad;
	       end = *p + mdsmap_len;
	}

	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
	m->m_epoch = ceph_decode_32(p);
	m->m_client_epoch = ceph_decode_32(p);
	m->m_last_failure = ceph_decode_32(p);
	m->m_root = ceph_decode_32(p);
	m->m_session_timeout = ceph_decode_32(p);
	m->m_session_autoclose = ceph_decode_32(p);
	m->m_max_file_size = ceph_decode_64(p);
	m->m_max_mds = ceph_decode_32(p);

	/*
	 * pick out the active nodes as the m_num_active_mds, the
	 * m_num_active_mds maybe larger than m_max_mds when decreasing
	 * the max_mds in cluster side, in other case it should less
	 * than or equal to m_max_mds.
	 */
	m->m_num_active_mds = n = ceph_decode_32(p);

	/*
	 * the possible max rank, it maybe larger than the m_num_active_mds,
	 * for example if the mds_max == 2 in the cluster, when the MDS(0)
	 * was laggy and being replaced by a new MDS, we will temporarily
	 * receive a new mds map with n_num_mds == 1 and the active MDS(1),
	 * and the mds rank >= m_num_active_mds.
	 */
	m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);

	m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
	if (!m->m_info)
		goto nomem;

	/* pick out active nodes from mds_info (state > 0) */
	for (i = 0; i < n; i++) {
		u64 global_id;
		u32 namelen;
		s32 mds, inc, state;
		u8 info_v;
		void *info_end = NULL;
		struct ceph_entity_addr addr;
		u32 num_export_targets;
		void *pexport_targets = NULL;
		struct ceph_timespec laggy_since;
		struct ceph_mds_info *info;
		bool laggy;

		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
		global_id = ceph_decode_64(p);
		info_v= ceph_decode_8(p);
		if (info_v >= 4) {
			u32 info_len;
			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
			*p += sizeof(u8);	/* info_cv */
			info_len = ceph_decode_32(p);
			info_end = *p + info_len;
			if (info_end > end)
				goto bad;
		}

		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
		*p += sizeof(u64);
		namelen = ceph_decode_32(p);  /* skip mds name */
		*p += namelen;

		ceph_decode_32_safe(p, end, mds, bad);
		ceph_decode_32_safe(p, end, inc, bad);
		ceph_decode_32_safe(p, end, state, bad);
		*p += sizeof(u64);		/* state_seq */
		if (info_v >= 8)
			err = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
		else
			err = ceph_decode_entity_addr(p, end, &addr);
		if (err)
			goto corrupt;

		ceph_decode_copy_safe(p, end, &laggy_since, sizeof(laggy_since),
				      bad);
		laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
		*p += sizeof(u32);
		ceph_decode_32_safe(p, end, namelen, bad);
		*p += namelen;
		if (info_v >= 2) {
			ceph_decode_32_safe(p, end, num_export_targets, bad);
			pexport_targets = *p;
			*p += num_export_targets * sizeof(u32);
		} else {
			num_export_targets = 0;
		}

		if (info_end && *p != info_end) {
			if (*p > info_end)
				goto bad;
			*p = info_end;
		}

		doutc(cl, "%d/%d %lld mds%d.%d %s %s%s\n", i+1, n, global_id,
		      mds, inc, ceph_pr_addr(&addr),
		      ceph_mds_state_name(state), laggy ? "(laggy)" : "");

		if (mds < 0 || mds >= m->possible_max_rank) {
			pr_warn_client(cl, "got incorrect mds(%d)\n", mds);
			continue;
		}

		if (state <= 0) {
			doutc(cl, "got incorrect state(%s)\n",
			      ceph_mds_state_name(state));
			continue;
		}

		info = &m->m_info[mds];
		info->global_id = global_id;
		info->state = state;
		info->addr = addr;
		info->laggy = laggy;
		info->num_export_targets = num_export_targets;
		if (num_export_targets) {
			info->export_targets = kcalloc(num_export_targets,
						       sizeof(u32), GFP_NOFS);
			if (!info->export_targets)
				goto nomem;
			for (j = 0; j < num_export_targets; j++) {
				target = ceph_decode_32(&pexport_targets);
				info->export_targets[j] = target;
			}
		} else {
			info->export_targets = NULL;
		}
	}

	/* pg_pools */
	ceph_decode_32_safe(p, end, n, bad);
	m->m_num_data_pg_pools = n;
	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
	if (!m->m_data_pg_pools)
		goto nomem;
	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
	for (i = 0; i < n; i++)
		m->m_data_pg_pools[i] = ceph_decode_64(p);
	m->m_cas_pg_pool = ceph_decode_64(p);
	m->m_enabled = m->m_epoch > 1;

	mdsmap_ev = 1;
	if (mdsmap_v >= 2) {
		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
	}
	if (mdsmap_ev >= 3) {
		if (__decode_and_drop_compat_set(p, end) < 0)
			goto bad_ext;
	}
	/* metadata_pool */
	if (mdsmap_ev < 5) {
		__decode_and_drop_type(p, end, u32, bad_ext);
	} else {
		__decode_and_drop_type(p, end, u64, bad_ext);
	}

	/* created + modified + tableserver */
	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
	__decode_and_drop_type(p, end, u32, bad_ext);

	/* in */
	{
		int num_laggy = 0;
		ceph_decode_32_safe(p, end, n, bad_ext);
		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);

		for (i = 0; i < n; i++) {
			s32 mds = ceph_decode_32(p);
			if (mds >= 0 && mds < m->possible_max_rank) {
				if (m->m_info[mds].laggy)
					num_laggy++;
			}
		}
		m->m_num_laggy = num_laggy;

		if (n > m->possible_max_rank) {
			void *new_m_info = krealloc(m->m_info,
						    n * sizeof(*m->m_info),
						    GFP_NOFS | __GFP_ZERO);
			if (!new_m_info)
				goto nomem;
			m->m_info = new_m_info;
		}
		m->possible_max_rank = n;
	}

	/* inc */
	__decode_and_drop_map(p, end, u32, u32, bad_ext);
	/* up */
	__decode_and_drop_map(p, end, u32, u64, bad_ext);
	/* failed */
	__decode_and_drop_set(p, end, u32, bad_ext);
	/* stopped */
	__decode_and_drop_set(p, end, u32, bad_ext);

	if (mdsmap_ev >= 4) {
		/* last_failure_osd_epoch */
		__decode_and_drop_type(p, end, u32, bad_ext);
	}
	if (mdsmap_ev >= 6) {
		/* ever_allowed_snaps */
		__decode_and_drop_type(p, end, u8, bad_ext);
		/* explicitly_allowed_snaps */
		__decode_and_drop_type(p, end, u8, bad_ext);
	}
	if (mdsmap_ev >= 7) {
		/* inline_data_enabled */
		__decode_and_drop_type(p, end, u8, bad_ext);
	}
	if (mdsmap_ev >= 8) {
		/* enabled */
		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
		/* fs_name */
		ceph_decode_skip_string(p, end, bad_ext);
	}
	/* damaged */
	if (mdsmap_ev >= 9) {
		size_t need;
		ceph_decode_32_safe(p, end, n, bad_ext);
		need = sizeof(u32) * n;
		ceph_decode_need(p, end, need, bad_ext);
		*p += need;
		m->m_damaged = n > 0;
	} else {
		m->m_damaged = false;
	}
	if (mdsmap_ev >= 17) {
		/* balancer */
		ceph_decode_skip_string(p, end, bad_ext);
		/* standby_count_wanted */
		ceph_decode_skip_32(p, end, bad_ext);
		/* old_max_mds */
		ceph_decode_skip_32(p, end, bad_ext);
		/* min_compat_client */
		ceph_decode_skip_8(p, end, bad_ext);
		/* required_client_features */
		ceph_decode_skip_set(p, end, 64, bad_ext);
		ceph_decode_64_safe(p, end, m->m_max_xattr_size, bad_ext);
	} else {
		/* This forces the usage of the (sync) SETXATTR Op */
		m->m_max_xattr_size = 0;
	}
bad_ext:
	doutc(cl, "m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
	      !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
	*p = end;
	doutc(cl, "success epoch %u\n", m->m_epoch);
	return m;
nomem:
	err = -ENOMEM;
	goto out_err;
corrupt:
	pr_err_client(cl, "corrupt mdsmap\n");
	print_hex_dump(KERN_DEBUG, "mdsmap: ",
		       DUMP_PREFIX_OFFSET, 16, 1,
		       start, end - start, true);
out_err:
	ceph_mdsmap_destroy(m);
	return ERR_PTR(err);
bad:
	err = -EINVAL;
	goto corrupt;
}

void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
{
	int i;

	if (m->m_info) {
		for (i = 0; i < m->possible_max_rank; i++)
			kfree(m->m_info[i].export_targets);
		kfree(m->m_info);
	}
	kfree(m->m_data_pg_pools);
	kfree(m);
}

bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
{
	int i, nr_active = 0;
	if (!m->m_enabled)
		return false;
	if (m->m_damaged)
		return false;
	if (m->m_num_laggy == m->m_num_active_mds)
		return false;
	for (i = 0; i < m->possible_max_rank; i++) {
		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
			nr_active++;
	}
	return nr_active > 0;
}