xref: /openbmc/linux/fs/ceph/mdsmap.c (revision c8ec3743)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3 
4 #include <linux/bug.h>
5 #include <linux/err.h>
6 #include <linux/random.h>
7 #include <linux/slab.h>
8 #include <linux/types.h>
9 
10 #include <linux/ceph/mdsmap.h>
11 #include <linux/ceph/messenger.h>
12 #include <linux/ceph/decode.h>
13 
14 #include "super.h"
15 
16 
17 /*
18  * choose a random mds that is "up" (i.e. has a state > 0), or -1.
19  */
20 int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
21 {
22 	int n = 0;
23 	int i;
24 
25 	/* special case for one mds */
26 	if (1 == m->m_num_mds && m->m_info[0].state > 0)
27 		return 0;
28 
29 	/* count */
30 	for (i = 0; i < m->m_num_mds; i++)
31 		if (m->m_info[i].state > 0)
32 			n++;
33 	if (n == 0)
34 		return -1;
35 
36 	/* pick */
37 	n = prandom_u32() % n;
38 	for (i = 0; n > 0; i++, n--)
39 		while (m->m_info[i].state <= 0)
40 			i++;
41 
42 	return i;
43 }
44 
45 #define __decode_and_drop_type(p, end, type, bad)		\
46 	do {							\
47 		if (*p + sizeof(type) > end)			\
48 			goto bad;				\
49 		*p += sizeof(type);				\
50 	} while (0)
51 
52 #define __decode_and_drop_set(p, end, type, bad)		\
53 	do {							\
54 		u32 n;						\
55 		size_t need;					\
56 		ceph_decode_32_safe(p, end, n, bad);		\
57 		need = sizeof(type) * n;			\
58 		ceph_decode_need(p, end, need, bad);		\
59 		*p += need;					\
60 	} while (0)
61 
62 #define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
63 	do {							\
64 		u32 n;						\
65 		size_t need;					\
66 		ceph_decode_32_safe(p, end, n, bad);		\
67 		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
68 		ceph_decode_need(p, end, need, bad);		\
69 		*p += need;					\
70 	} while (0)
71 
72 
73 static int __decode_and_drop_compat_set(void **p, void* end)
74 {
75 	int i;
76 	/* compat, ro_compat, incompat*/
77 	for (i = 0; i < 3; i++) {
78 		u32 n;
79 		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
80 		/* mask */
81 		*p += sizeof(u64);
82 		/* names (map<u64, string>) */
83 		n = ceph_decode_32(p);
84 		while (n-- > 0) {
85 			u32 len;
86 			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
87 					 bad);
88 			*p += sizeof(u64);
89 			len = ceph_decode_32(p);
90 			ceph_decode_need(p, end, len, bad);
91 			*p += len;
92 		}
93 	}
94 	return 0;
95 bad:
96 	return -1;
97 }
98 
99 /*
100  * Decode an MDS map
101  *
102  * Ignore any fields we don't care about (there are quite a few of
103  * them).
104  */
105 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
106 {
107 	struct ceph_mdsmap *m;
108 	const void *start = *p;
109 	int i, j, n;
110 	int err = -EINVAL;
111 	u8 mdsmap_v, mdsmap_cv;
112 	u16 mdsmap_ev;
113 
114 	m = kzalloc(sizeof(*m), GFP_NOFS);
115 	if (!m)
116 		return ERR_PTR(-ENOMEM);
117 
118 	ceph_decode_need(p, end, 1 + 1, bad);
119 	mdsmap_v = ceph_decode_8(p);
120 	mdsmap_cv = ceph_decode_8(p);
121 	if (mdsmap_v >= 4) {
122 	       u32 mdsmap_len;
123 	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
124 	       if (end < *p + mdsmap_len)
125 		       goto bad;
126 	       end = *p + mdsmap_len;
127 	}
128 
129 	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
130 	m->m_epoch = ceph_decode_32(p);
131 	m->m_client_epoch = ceph_decode_32(p);
132 	m->m_last_failure = ceph_decode_32(p);
133 	m->m_root = ceph_decode_32(p);
134 	m->m_session_timeout = ceph_decode_32(p);
135 	m->m_session_autoclose = ceph_decode_32(p);
136 	m->m_max_file_size = ceph_decode_64(p);
137 	m->m_max_mds = ceph_decode_32(p);
138 	m->m_num_mds = m->m_max_mds;
139 
140 	m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
141 	if (!m->m_info)
142 		goto nomem;
143 
144 	/* pick out active nodes from mds_info (state > 0) */
145 	n = ceph_decode_32(p);
146 	for (i = 0; i < n; i++) {
147 		u64 global_id;
148 		u32 namelen;
149 		s32 mds, inc, state;
150 		u64 state_seq;
151 		u8 info_v;
152 		void *info_end = NULL;
153 		struct ceph_entity_addr addr;
154 		u32 num_export_targets;
155 		void *pexport_targets = NULL;
156 		struct ceph_timespec laggy_since;
157 		struct ceph_mds_info *info;
158 
159 		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
160 		global_id = ceph_decode_64(p);
161 		info_v= ceph_decode_8(p);
162 		if (info_v >= 4) {
163 			u32 info_len;
164 			u8 info_cv;
165 			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
166 			info_cv = ceph_decode_8(p);
167 			info_len = ceph_decode_32(p);
168 			info_end = *p + info_len;
169 			if (info_end > end)
170 				goto bad;
171 		}
172 
173 		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
174 		*p += sizeof(u64);
175 		namelen = ceph_decode_32(p);  /* skip mds name */
176 		*p += namelen;
177 
178 		ceph_decode_need(p, end,
179 				 4*sizeof(u32) + sizeof(u64) +
180 				 sizeof(addr) + sizeof(struct ceph_timespec),
181 				 bad);
182 		mds = ceph_decode_32(p);
183 		inc = ceph_decode_32(p);
184 		state = ceph_decode_32(p);
185 		state_seq = ceph_decode_64(p);
186 		ceph_decode_copy(p, &addr, sizeof(addr));
187 		ceph_decode_addr(&addr);
188 		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
189 		*p += sizeof(u32);
190 		ceph_decode_32_safe(p, end, namelen, bad);
191 		*p += namelen;
192 		if (info_v >= 2) {
193 			ceph_decode_32_safe(p, end, num_export_targets, bad);
194 			pexport_targets = *p;
195 			*p += num_export_targets * sizeof(u32);
196 		} else {
197 			num_export_targets = 0;
198 		}
199 
200 		if (info_end && *p != info_end) {
201 			if (*p > info_end)
202 				goto bad;
203 			*p = info_end;
204 		}
205 
206 		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
207 		     i+1, n, global_id, mds, inc,
208 		     ceph_pr_addr(&addr.in_addr),
209 		     ceph_mds_state_name(state));
210 
211 		if (mds < 0 || state <= 0)
212 			continue;
213 
214 		if (mds >= m->m_num_mds) {
215 			int new_num = max(mds + 1, m->m_num_mds * 2);
216 			void *new_m_info = krealloc(m->m_info,
217 						new_num * sizeof(*m->m_info),
218 						GFP_NOFS | __GFP_ZERO);
219 			if (!new_m_info)
220 				goto nomem;
221 			m->m_info = new_m_info;
222 			m->m_num_mds = new_num;
223 		}
224 
225 		info = &m->m_info[mds];
226 		info->global_id = global_id;
227 		info->state = state;
228 		info->addr = addr;
229 		info->laggy = (laggy_since.tv_sec != 0 ||
230 			       laggy_since.tv_nsec != 0);
231 		info->num_export_targets = num_export_targets;
232 		if (num_export_targets) {
233 			info->export_targets = kcalloc(num_export_targets,
234 						       sizeof(u32), GFP_NOFS);
235 			if (!info->export_targets)
236 				goto nomem;
237 			for (j = 0; j < num_export_targets; j++)
238 				info->export_targets[j] =
239 				       ceph_decode_32(&pexport_targets);
240 		} else {
241 			info->export_targets = NULL;
242 		}
243 	}
244 	if (m->m_num_mds > m->m_max_mds) {
245 		/* find max up mds */
246 		for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
247 			if (i == 0 || m->m_info[i-1].state > 0)
248 				break;
249 		}
250 		m->m_num_mds = i;
251 	}
252 
253 	/* pg_pools */
254 	ceph_decode_32_safe(p, end, n, bad);
255 	m->m_num_data_pg_pools = n;
256 	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
257 	if (!m->m_data_pg_pools)
258 		goto nomem;
259 	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
260 	for (i = 0; i < n; i++)
261 		m->m_data_pg_pools[i] = ceph_decode_64(p);
262 	m->m_cas_pg_pool = ceph_decode_64(p);
263 	m->m_enabled = m->m_epoch > 1;
264 
265 	mdsmap_ev = 1;
266 	if (mdsmap_v >= 2) {
267 		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
268 	}
269 	if (mdsmap_ev >= 3) {
270 		if (__decode_and_drop_compat_set(p, end) < 0)
271 			goto bad_ext;
272 	}
273 	/* metadata_pool */
274 	if (mdsmap_ev < 5) {
275 		__decode_and_drop_type(p, end, u32, bad_ext);
276 	} else {
277 		__decode_and_drop_type(p, end, u64, bad_ext);
278 	}
279 
280 	/* created + modified + tableserver */
281 	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
282 	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
283 	__decode_and_drop_type(p, end, u32, bad_ext);
284 
285 	/* in */
286 	{
287 		int num_laggy = 0;
288 		ceph_decode_32_safe(p, end, n, bad_ext);
289 		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
290 
291 		for (i = 0; i < n; i++) {
292 			s32 mds = ceph_decode_32(p);
293 			if (mds >= 0 && mds < m->m_num_mds) {
294 				if (m->m_info[mds].laggy)
295 					num_laggy++;
296 			}
297 		}
298 		m->m_num_laggy = num_laggy;
299 
300 		if (n > m->m_num_mds) {
301 			void *new_m_info = krealloc(m->m_info,
302 						    n * sizeof(*m->m_info),
303 						    GFP_NOFS | __GFP_ZERO);
304 			if (!new_m_info)
305 				goto nomem;
306 			m->m_info = new_m_info;
307 		}
308 		m->m_num_mds = n;
309 	}
310 
311 	/* inc */
312 	__decode_and_drop_map(p, end, u32, u32, bad_ext);
313 	/* up */
314 	__decode_and_drop_map(p, end, u32, u64, bad_ext);
315 	/* failed */
316 	__decode_and_drop_set(p, end, u32, bad_ext);
317 	/* stopped */
318 	__decode_and_drop_set(p, end, u32, bad_ext);
319 
320 	if (mdsmap_ev >= 4) {
321 		/* last_failure_osd_epoch */
322 		__decode_and_drop_type(p, end, u32, bad_ext);
323 	}
324 	if (mdsmap_ev >= 6) {
325 		/* ever_allowed_snaps */
326 		__decode_and_drop_type(p, end, u8, bad_ext);
327 		/* explicitly_allowed_snaps */
328 		__decode_and_drop_type(p, end, u8, bad_ext);
329 	}
330 	if (mdsmap_ev >= 7) {
331 		/* inline_data_enabled */
332 		__decode_and_drop_type(p, end, u8, bad_ext);
333 	}
334 	if (mdsmap_ev >= 8) {
335 		u32 name_len;
336 		/* enabled */
337 		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
338 		ceph_decode_32_safe(p, end, name_len, bad_ext);
339 		ceph_decode_need(p, end, name_len, bad_ext);
340 		*p += name_len;
341 	}
342 	/* damaged */
343 	if (mdsmap_ev >= 9) {
344 		size_t need;
345 		ceph_decode_32_safe(p, end, n, bad_ext);
346 		need = sizeof(u32) * n;
347 		ceph_decode_need(p, end, need, bad_ext);
348 		*p += need;
349 		m->m_damaged = n > 0;
350 	} else {
351 		m->m_damaged = false;
352 	}
353 bad_ext:
354 	*p = end;
355 	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
356 	return m;
357 nomem:
358 	err = -ENOMEM;
359 	goto out_err;
360 bad:
361 	pr_err("corrupt mdsmap\n");
362 	print_hex_dump(KERN_DEBUG, "mdsmap: ",
363 		       DUMP_PREFIX_OFFSET, 16, 1,
364 		       start, end - start, true);
365 out_err:
366 	ceph_mdsmap_destroy(m);
367 	return ERR_PTR(err);
368 }
369 
370 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
371 {
372 	int i;
373 
374 	for (i = 0; i < m->m_num_mds; i++)
375 		kfree(m->m_info[i].export_targets);
376 	kfree(m->m_info);
377 	kfree(m->m_data_pg_pools);
378 	kfree(m);
379 }
380 
381 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
382 {
383 	int i, nr_active = 0;
384 	if (!m->m_enabled)
385 		return false;
386 	if (m->m_damaged)
387 		return false;
388 	if (m->m_num_laggy > 0)
389 		return false;
390 	for (i = 0; i < m->m_num_mds; i++) {
391 		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
392 			nr_active++;
393 	}
394 	return nr_active > 0;
395 }
396