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  */
ceph_mdsmap_get_random_mds(struct ceph_mdsmap * m)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 	i = 0;
39 	for (i = 0; n > 0; i++, n--)
40 		while (m->m_info[i].state <= 0)
41 			i++;
42 
43 	return i;
44 }
45 
46 #define __decode_and_drop_type(p, end, type, bad)		\
47 	do {							\
48 		if (*p + sizeof(type) > end)			\
49 			goto bad;				\
50 		*p += sizeof(type);				\
51 	} while (0)
52 
53 #define __decode_and_drop_set(p, end, type, bad)		\
54 	do {							\
55 		u32 n;						\
56 		size_t need;					\
57 		ceph_decode_32_safe(p, end, n, bad);		\
58 		need = sizeof(type) * n;			\
59 		ceph_decode_need(p, end, need, bad);		\
60 		*p += need;					\
61 	} while (0)
62 
63 #define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
64 	do {							\
65 		u32 n;						\
66 		size_t need;					\
67 		ceph_decode_32_safe(p, end, n, bad);		\
68 		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
69 		ceph_decode_need(p, end, need, bad);		\
70 		*p += need;					\
71 	} while (0)
72 
73 
__decode_and_drop_compat_set(void ** p,void * end)74 static int __decode_and_drop_compat_set(void **p, void* end)
75 {
76 	int i;
77 	/* compat, ro_compat, incompat*/
78 	for (i = 0; i < 3; i++) {
79 		u32 n;
80 		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
81 		/* mask */
82 		*p += sizeof(u64);
83 		/* names (map<u64, string>) */
84 		n = ceph_decode_32(p);
85 		while (n-- > 0) {
86 			u32 len;
87 			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
88 					 bad);
89 			*p += sizeof(u64);
90 			len = ceph_decode_32(p);
91 			ceph_decode_need(p, end, len, bad);
92 			*p += len;
93 		}
94 	}
95 	return 0;
96 bad:
97 	return -1;
98 }
99 
100 /*
101  * Decode an MDS map
102  *
103  * Ignore any fields we don't care about (there are quite a few of
104  * them).
105  */
ceph_mdsmap_decode(void ** p,void * end)106 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
107 {
108 	struct ceph_mdsmap *m;
109 	const void *start = *p;
110 	int i, j, n;
111 	int err = -EINVAL;
112 	u8 mdsmap_v, mdsmap_cv;
113 	u16 mdsmap_ev;
114 
115 	m = kzalloc(sizeof(*m), GFP_NOFS);
116 	if (!m)
117 		return ERR_PTR(-ENOMEM);
118 
119 	ceph_decode_need(p, end, 1 + 1, bad);
120 	mdsmap_v = ceph_decode_8(p);
121 	mdsmap_cv = ceph_decode_8(p);
122 	if (mdsmap_v >= 4) {
123 	       u32 mdsmap_len;
124 	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
125 	       if (end < *p + mdsmap_len)
126 		       goto bad;
127 	       end = *p + mdsmap_len;
128 	}
129 
130 	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
131 	m->m_epoch = ceph_decode_32(p);
132 	m->m_client_epoch = ceph_decode_32(p);
133 	m->m_last_failure = ceph_decode_32(p);
134 	m->m_root = ceph_decode_32(p);
135 	m->m_session_timeout = ceph_decode_32(p);
136 	m->m_session_autoclose = ceph_decode_32(p);
137 	m->m_max_file_size = ceph_decode_64(p);
138 	m->m_max_mds = ceph_decode_32(p);
139 	m->m_num_mds = m->m_max_mds;
140 
141 	m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
142 	if (!m->m_info)
143 		goto nomem;
144 
145 	/* pick out active nodes from mds_info (state > 0) */
146 	n = ceph_decode_32(p);
147 	for (i = 0; i < n; i++) {
148 		u64 global_id;
149 		u32 namelen;
150 		s32 mds, inc, state;
151 		u64 state_seq;
152 		u8 info_v;
153 		void *info_end = NULL;
154 		struct ceph_entity_addr addr;
155 		u32 num_export_targets;
156 		void *pexport_targets = NULL;
157 		struct ceph_timespec laggy_since;
158 		struct ceph_mds_info *info;
159 
160 		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
161 		global_id = ceph_decode_64(p);
162 		info_v= ceph_decode_8(p);
163 		if (info_v >= 4) {
164 			u32 info_len;
165 			u8 info_cv;
166 			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
167 			info_cv = ceph_decode_8(p);
168 			info_len = ceph_decode_32(p);
169 			info_end = *p + info_len;
170 			if (info_end > end)
171 				goto bad;
172 		}
173 
174 		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
175 		*p += sizeof(u64);
176 		namelen = ceph_decode_32(p);  /* skip mds name */
177 		*p += namelen;
178 
179 		ceph_decode_need(p, end,
180 				 4*sizeof(u32) + sizeof(u64) +
181 				 sizeof(addr) + sizeof(struct ceph_timespec),
182 				 bad);
183 		mds = ceph_decode_32(p);
184 		inc = ceph_decode_32(p);
185 		state = ceph_decode_32(p);
186 		state_seq = ceph_decode_64(p);
187 		ceph_decode_copy(p, &addr, sizeof(addr));
188 		ceph_decode_addr(&addr);
189 		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
190 		*p += sizeof(u32);
191 		ceph_decode_32_safe(p, end, namelen, bad);
192 		*p += namelen;
193 		if (info_v >= 2) {
194 			ceph_decode_32_safe(p, end, num_export_targets, bad);
195 			pexport_targets = *p;
196 			*p += num_export_targets * sizeof(u32);
197 		} else {
198 			num_export_targets = 0;
199 		}
200 
201 		if (info_end && *p != info_end) {
202 			if (*p > info_end)
203 				goto bad;
204 			*p = info_end;
205 		}
206 
207 		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
208 		     i+1, n, global_id, mds, inc,
209 		     ceph_pr_addr(&addr.in_addr),
210 		     ceph_mds_state_name(state));
211 
212 		if (mds < 0 || state <= 0)
213 			continue;
214 
215 		if (mds >= m->m_num_mds) {
216 			int new_num = max(mds + 1, m->m_num_mds * 2);
217 			void *new_m_info = krealloc(m->m_info,
218 						new_num * sizeof(*m->m_info),
219 						GFP_NOFS | __GFP_ZERO);
220 			if (!new_m_info)
221 				goto nomem;
222 			m->m_info = new_m_info;
223 			m->m_num_mds = new_num;
224 		}
225 
226 		info = &m->m_info[mds];
227 		info->global_id = global_id;
228 		info->state = state;
229 		info->addr = addr;
230 		info->laggy = (laggy_since.tv_sec != 0 ||
231 			       laggy_since.tv_nsec != 0);
232 		info->num_export_targets = num_export_targets;
233 		if (num_export_targets) {
234 			info->export_targets = kcalloc(num_export_targets,
235 						       sizeof(u32), GFP_NOFS);
236 			if (!info->export_targets)
237 				goto nomem;
238 			for (j = 0; j < num_export_targets; j++)
239 				info->export_targets[j] =
240 				       ceph_decode_32(&pexport_targets);
241 		} else {
242 			info->export_targets = NULL;
243 		}
244 	}
245 	if (m->m_num_mds > m->m_max_mds) {
246 		/* find max up mds */
247 		for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
248 			if (i == 0 || m->m_info[i-1].state > 0)
249 				break;
250 		}
251 		m->m_num_mds = i;
252 	}
253 
254 	/* pg_pools */
255 	ceph_decode_32_safe(p, end, n, bad);
256 	m->m_num_data_pg_pools = n;
257 	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
258 	if (!m->m_data_pg_pools)
259 		goto nomem;
260 	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
261 	for (i = 0; i < n; i++)
262 		m->m_data_pg_pools[i] = ceph_decode_64(p);
263 	m->m_cas_pg_pool = ceph_decode_64(p);
264 	m->m_enabled = m->m_epoch > 1;
265 
266 	mdsmap_ev = 1;
267 	if (mdsmap_v >= 2) {
268 		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
269 	}
270 	if (mdsmap_ev >= 3) {
271 		if (__decode_and_drop_compat_set(p, end) < 0)
272 			goto bad_ext;
273 	}
274 	/* metadata_pool */
275 	if (mdsmap_ev < 5) {
276 		__decode_and_drop_type(p, end, u32, bad_ext);
277 	} else {
278 		__decode_and_drop_type(p, end, u64, bad_ext);
279 	}
280 
281 	/* created + modified + tableserver */
282 	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
283 	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
284 	__decode_and_drop_type(p, end, u32, bad_ext);
285 
286 	/* in */
287 	{
288 		int num_laggy = 0;
289 		ceph_decode_32_safe(p, end, n, bad_ext);
290 		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
291 
292 		for (i = 0; i < n; i++) {
293 			s32 mds = ceph_decode_32(p);
294 			if (mds >= 0 && mds < m->m_num_mds) {
295 				if (m->m_info[mds].laggy)
296 					num_laggy++;
297 			}
298 		}
299 		m->m_num_laggy = num_laggy;
300 
301 		if (n > m->m_num_mds) {
302 			void *new_m_info = krealloc(m->m_info,
303 						    n * sizeof(*m->m_info),
304 						    GFP_NOFS | __GFP_ZERO);
305 			if (!new_m_info)
306 				goto nomem;
307 			m->m_info = new_m_info;
308 		}
309 		m->m_num_mds = n;
310 	}
311 
312 	/* inc */
313 	__decode_and_drop_map(p, end, u32, u32, bad_ext);
314 	/* up */
315 	__decode_and_drop_map(p, end, u32, u64, bad_ext);
316 	/* failed */
317 	__decode_and_drop_set(p, end, u32, bad_ext);
318 	/* stopped */
319 	__decode_and_drop_set(p, end, u32, bad_ext);
320 
321 	if (mdsmap_ev >= 4) {
322 		/* last_failure_osd_epoch */
323 		__decode_and_drop_type(p, end, u32, bad_ext);
324 	}
325 	if (mdsmap_ev >= 6) {
326 		/* ever_allowed_snaps */
327 		__decode_and_drop_type(p, end, u8, bad_ext);
328 		/* explicitly_allowed_snaps */
329 		__decode_and_drop_type(p, end, u8, bad_ext);
330 	}
331 	if (mdsmap_ev >= 7) {
332 		/* inline_data_enabled */
333 		__decode_and_drop_type(p, end, u8, bad_ext);
334 	}
335 	if (mdsmap_ev >= 8) {
336 		u32 name_len;
337 		/* enabled */
338 		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
339 		ceph_decode_32_safe(p, end, name_len, bad_ext);
340 		ceph_decode_need(p, end, name_len, bad_ext);
341 		*p += name_len;
342 	}
343 	/* damaged */
344 	if (mdsmap_ev >= 9) {
345 		size_t need;
346 		ceph_decode_32_safe(p, end, n, bad_ext);
347 		need = sizeof(u32) * n;
348 		ceph_decode_need(p, end, need, bad_ext);
349 		*p += need;
350 		m->m_damaged = n > 0;
351 	} else {
352 		m->m_damaged = false;
353 	}
354 bad_ext:
355 	*p = end;
356 	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
357 	return m;
358 nomem:
359 	err = -ENOMEM;
360 	goto out_err;
361 bad:
362 	pr_err("corrupt mdsmap\n");
363 	print_hex_dump(KERN_DEBUG, "mdsmap: ",
364 		       DUMP_PREFIX_OFFSET, 16, 1,
365 		       start, end - start, true);
366 out_err:
367 	ceph_mdsmap_destroy(m);
368 	return ERR_PTR(err);
369 }
370 
ceph_mdsmap_destroy(struct ceph_mdsmap * m)371 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
372 {
373 	int i;
374 
375 	for (i = 0; i < m->m_num_mds; i++)
376 		kfree(m->m_info[i].export_targets);
377 	kfree(m->m_info);
378 	kfree(m->m_data_pg_pools);
379 	kfree(m);
380 }
381 
ceph_mdsmap_is_cluster_available(struct ceph_mdsmap * m)382 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
383 {
384 	int i, nr_active = 0;
385 	if (!m->m_enabled)
386 		return false;
387 	if (m->m_damaged)
388 		return false;
389 	if (m->m_num_laggy > 0)
390 		return false;
391 	for (i = 0; i < m->m_num_mds; i++) {
392 		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
393 			nr_active++;
394 	}
395 	return nr_active > 0;
396 }
397