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v5.9
  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#define CEPH_MDS_IS_READY(i, ignore_laggy) \
 17	(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
 18
 19static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 20{
 21	int n = 0;
 22	int i, j;
 23
 24	/* count */
 25	for (i = 0; i < m->possible_max_rank; i++)
 26		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 27			n++;
 28	if (n == 0)
 29		return -1;
 30
 31	/* pick */
 32	n = prandom_u32() % n;
 33	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
 34		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 35			j++;
 36		if (j > n)
 37			break;
 38	}
 39
 40	return i;
 41}
 42
 43/*
 44 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
 45 */
 46int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
 47{
 48	int mds;
 49
 50	mds = __mdsmap_get_random_mds(m, false);
 51	if (mds == m->possible_max_rank || mds == -1)
 52		mds = __mdsmap_get_random_mds(m, true);
 53
 54	return mds == m->possible_max_rank ? -1 : mds;
 55}
 56
 57#define __decode_and_drop_type(p, end, type, bad)		\
 58	do {							\
 59		if (*p + sizeof(type) > end)			\
 60			goto bad;				\
 61		*p += sizeof(type);				\
 62	} while (0)
 63
 64#define __decode_and_drop_set(p, end, type, bad)		\
 65	do {							\
 66		u32 n;						\
 67		size_t need;					\
 68		ceph_decode_32_safe(p, end, n, bad);		\
 69		need = sizeof(type) * n;			\
 70		ceph_decode_need(p, end, need, bad);		\
 71		*p += need;					\
 72	} while (0)
 73
 74#define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
 75	do {							\
 76		u32 n;						\
 77		size_t need;					\
 78		ceph_decode_32_safe(p, end, n, bad);		\
 79		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
 80		ceph_decode_need(p, end, need, bad);		\
 81		*p += need;					\
 82	} while (0)
 83
 84
 85static int __decode_and_drop_compat_set(void **p, void* end)
 86{
 87	int i;
 88	/* compat, ro_compat, incompat*/
 89	for (i = 0; i < 3; i++) {
 90		u32 n;
 91		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 92		/* mask */
 93		*p += sizeof(u64);
 94		/* names (map<u64, string>) */
 95		n = ceph_decode_32(p);
 96		while (n-- > 0) {
 97			u32 len;
 98			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
 99					 bad);
100			*p += sizeof(u64);
101			len = ceph_decode_32(p);
102			ceph_decode_need(p, end, len, bad);
103			*p += len;
104		}
105	}
106	return 0;
107bad:
108	return -1;
109}
110
111/*
112 * Decode an MDS map
113 *
114 * Ignore any fields we don't care about (there are quite a few of
115 * them).
116 */
117struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 
118{
 
119	struct ceph_mdsmap *m;
120	const void *start = *p;
121	int i, j, n;
122	int err;
123	u8 mdsmap_v;
124	u16 mdsmap_ev;
 
125
126	m = kzalloc(sizeof(*m), GFP_NOFS);
127	if (!m)
128		return ERR_PTR(-ENOMEM);
129
130	ceph_decode_need(p, end, 1 + 1, bad);
131	mdsmap_v = ceph_decode_8(p);
132	*p += sizeof(u8);			/* mdsmap_cv */
133	if (mdsmap_v >= 4) {
134	       u32 mdsmap_len;
135	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
136	       if (end < *p + mdsmap_len)
137		       goto bad;
138	       end = *p + mdsmap_len;
139	}
140
141	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
142	m->m_epoch = ceph_decode_32(p);
143	m->m_client_epoch = ceph_decode_32(p);
144	m->m_last_failure = ceph_decode_32(p);
145	m->m_root = ceph_decode_32(p);
146	m->m_session_timeout = ceph_decode_32(p);
147	m->m_session_autoclose = ceph_decode_32(p);
148	m->m_max_file_size = ceph_decode_64(p);
149	m->m_max_mds = ceph_decode_32(p);
150
151	/*
152	 * pick out the active nodes as the m_num_active_mds, the
153	 * m_num_active_mds maybe larger than m_max_mds when decreasing
154	 * the max_mds in cluster side, in other case it should less
155	 * than or equal to m_max_mds.
156	 */
157	m->m_num_active_mds = n = ceph_decode_32(p);
158
159	/*
160	 * the possible max rank, it maybe larger than the m_num_active_mds,
161	 * for example if the mds_max == 2 in the cluster, when the MDS(0)
162	 * was laggy and being replaced by a new MDS, we will temporarily
163	 * receive a new mds map with n_num_mds == 1 and the active MDS(1),
164	 * and the mds rank >= m_num_active_mds.
165	 */
166	m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
167
168	m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
169	if (!m->m_info)
170		goto nomem;
171
172	/* pick out active nodes from mds_info (state > 0) */
173	for (i = 0; i < n; i++) {
174		u64 global_id;
175		u32 namelen;
176		s32 mds, inc, state;
177		u8 info_v;
178		void *info_end = NULL;
179		struct ceph_entity_addr addr;
180		u32 num_export_targets;
181		void *pexport_targets = NULL;
182		struct ceph_timespec laggy_since;
183		struct ceph_mds_info *info;
184		bool laggy;
185
186		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
187		global_id = ceph_decode_64(p);
188		info_v= ceph_decode_8(p);
189		if (info_v >= 4) {
190			u32 info_len;
191			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
192			*p += sizeof(u8);	/* info_cv */
193			info_len = ceph_decode_32(p);
194			info_end = *p + info_len;
195			if (info_end > end)
196				goto bad;
197		}
198
199		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
200		*p += sizeof(u64);
201		namelen = ceph_decode_32(p);  /* skip mds name */
202		*p += namelen;
203
204		ceph_decode_need(p, end,
205				 4*sizeof(u32) + sizeof(u64) +
206				 sizeof(addr) + sizeof(struct ceph_timespec),
207				 bad);
208		mds = ceph_decode_32(p);
209		inc = ceph_decode_32(p);
210		state = ceph_decode_32(p);
211		*p += sizeof(u64);		/* state_seq */
212		err = ceph_decode_entity_addr(p, end, &addr);
 
 
 
213		if (err)
214			goto corrupt;
215		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
 
 
216		laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
217		*p += sizeof(u32);
218		ceph_decode_32_safe(p, end, namelen, bad);
219		*p += namelen;
220		if (info_v >= 2) {
221			ceph_decode_32_safe(p, end, num_export_targets, bad);
222			pexport_targets = *p;
223			*p += num_export_targets * sizeof(u32);
224		} else {
225			num_export_targets = 0;
226		}
227
228		if (info_end && *p != info_end) {
229			if (*p > info_end)
230				goto bad;
231			*p = info_end;
232		}
233
234		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s%s\n",
235		     i+1, n, global_id, mds, inc,
236		     ceph_pr_addr(&addr),
237		     ceph_mds_state_name(state),
238		     laggy ? "(laggy)" : "");
239
240		if (mds < 0 || mds >= m->possible_max_rank) {
241			pr_warn("mdsmap_decode got incorrect mds(%d)\n", mds);
242			continue;
243		}
244
245		if (state <= 0) {
246			pr_warn("mdsmap_decode got incorrect state(%s)\n",
247				ceph_mds_state_name(state));
248			continue;
249		}
250
251		info = &m->m_info[mds];
252		info->global_id = global_id;
253		info->state = state;
254		info->addr = addr;
255		info->laggy = laggy;
256		info->num_export_targets = num_export_targets;
257		if (num_export_targets) {
258			info->export_targets = kcalloc(num_export_targets,
259						       sizeof(u32), GFP_NOFS);
260			if (!info->export_targets)
261				goto nomem;
262			for (j = 0; j < num_export_targets; j++)
263				info->export_targets[j] =
264				       ceph_decode_32(&pexport_targets);
 
265		} else {
266			info->export_targets = NULL;
267		}
268	}
269
270	/* pg_pools */
271	ceph_decode_32_safe(p, end, n, bad);
272	m->m_num_data_pg_pools = n;
273	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
274	if (!m->m_data_pg_pools)
275		goto nomem;
276	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
277	for (i = 0; i < n; i++)
278		m->m_data_pg_pools[i] = ceph_decode_64(p);
279	m->m_cas_pg_pool = ceph_decode_64(p);
280	m->m_enabled = m->m_epoch > 1;
281
282	mdsmap_ev = 1;
283	if (mdsmap_v >= 2) {
284		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
285	}
286	if (mdsmap_ev >= 3) {
287		if (__decode_and_drop_compat_set(p, end) < 0)
288			goto bad_ext;
289	}
290	/* metadata_pool */
291	if (mdsmap_ev < 5) {
292		__decode_and_drop_type(p, end, u32, bad_ext);
293	} else {
294		__decode_and_drop_type(p, end, u64, bad_ext);
295	}
296
297	/* created + modified + tableserver */
298	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
299	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
300	__decode_and_drop_type(p, end, u32, bad_ext);
301
302	/* in */
303	{
304		int num_laggy = 0;
305		ceph_decode_32_safe(p, end, n, bad_ext);
306		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
307
308		for (i = 0; i < n; i++) {
309			s32 mds = ceph_decode_32(p);
310			if (mds >= 0 && mds < m->possible_max_rank) {
311				if (m->m_info[mds].laggy)
312					num_laggy++;
313			}
314		}
315		m->m_num_laggy = num_laggy;
316
317		if (n > m->possible_max_rank) {
318			void *new_m_info = krealloc(m->m_info,
319						    n * sizeof(*m->m_info),
320						    GFP_NOFS | __GFP_ZERO);
321			if (!new_m_info)
322				goto nomem;
323			m->m_info = new_m_info;
324		}
325		m->possible_max_rank = n;
326	}
327
328	/* inc */
329	__decode_and_drop_map(p, end, u32, u32, bad_ext);
330	/* up */
331	__decode_and_drop_map(p, end, u32, u64, bad_ext);
332	/* failed */
333	__decode_and_drop_set(p, end, u32, bad_ext);
334	/* stopped */
335	__decode_and_drop_set(p, end, u32, bad_ext);
336
337	if (mdsmap_ev >= 4) {
338		/* last_failure_osd_epoch */
339		__decode_and_drop_type(p, end, u32, bad_ext);
340	}
341	if (mdsmap_ev >= 6) {
342		/* ever_allowed_snaps */
343		__decode_and_drop_type(p, end, u8, bad_ext);
344		/* explicitly_allowed_snaps */
345		__decode_and_drop_type(p, end, u8, bad_ext);
346	}
347	if (mdsmap_ev >= 7) {
348		/* inline_data_enabled */
349		__decode_and_drop_type(p, end, u8, bad_ext);
350	}
351	if (mdsmap_ev >= 8) {
352		u32 name_len;
353		/* enabled */
354		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
355		ceph_decode_32_safe(p, end, name_len, bad_ext);
356		ceph_decode_need(p, end, name_len, bad_ext);
357		*p += name_len;
358	}
359	/* damaged */
360	if (mdsmap_ev >= 9) {
361		size_t need;
362		ceph_decode_32_safe(p, end, n, bad_ext);
363		need = sizeof(u32) * n;
364		ceph_decode_need(p, end, need, bad_ext);
365		*p += need;
366		m->m_damaged = n > 0;
367	} else {
368		m->m_damaged = false;
369	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
370bad_ext:
371	dout("mdsmap_decode m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
372	     !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
373	*p = end;
374	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
375	return m;
376nomem:
377	err = -ENOMEM;
378	goto out_err;
379corrupt:
380	pr_err("corrupt mdsmap\n");
381	print_hex_dump(KERN_DEBUG, "mdsmap: ",
382		       DUMP_PREFIX_OFFSET, 16, 1,
383		       start, end - start, true);
384out_err:
385	ceph_mdsmap_destroy(m);
386	return ERR_PTR(err);
387bad:
388	err = -EINVAL;
389	goto corrupt;
390}
391
392void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
393{
394	int i;
395
396	for (i = 0; i < m->possible_max_rank; i++)
397		kfree(m->m_info[i].export_targets);
398	kfree(m->m_info);
 
 
399	kfree(m->m_data_pg_pools);
400	kfree(m);
401}
402
403bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
404{
405	int i, nr_active = 0;
406	if (!m->m_enabled)
407		return false;
408	if (m->m_damaged)
409		return false;
410	if (m->m_num_laggy == m->m_num_active_mds)
411		return false;
412	for (i = 0; i < m->possible_max_rank; i++) {
413		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
414			nr_active++;
415	}
416	return nr_active > 0;
417}
v6.9.4
  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/messenger.h>
 11#include <linux/ceph/decode.h>
 12
 13#include "mdsmap.h"
 14#include "mds_client.h"
 15#include "super.h"
 16
 17#define CEPH_MDS_IS_READY(i, ignore_laggy) \
 18	(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
 19
 20static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 21{
 22	int n = 0;
 23	int i, j;
 24
 25	/* count */
 26	for (i = 0; i < m->possible_max_rank; i++)
 27		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 28			n++;
 29	if (n == 0)
 30		return -1;
 31
 32	/* pick */
 33	n = get_random_u32_below(n);
 34	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
 35		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 36			j++;
 37		if (j > n)
 38			break;
 39	}
 40
 41	return i;
 42}
 43
 44/*
 45 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
 46 */
 47int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
 48{
 49	int mds;
 50
 51	mds = __mdsmap_get_random_mds(m, false);
 52	if (mds == m->possible_max_rank || mds == -1)
 53		mds = __mdsmap_get_random_mds(m, true);
 54
 55	return mds == m->possible_max_rank ? -1 : mds;
 56}
 57
 58#define __decode_and_drop_type(p, end, type, bad)		\
 59	do {							\
 60		if (*p + sizeof(type) > end)			\
 61			goto bad;				\
 62		*p += sizeof(type);				\
 63	} while (0)
 64
 65#define __decode_and_drop_set(p, end, type, bad)		\
 66	do {							\
 67		u32 n;						\
 68		size_t need;					\
 69		ceph_decode_32_safe(p, end, n, bad);		\
 70		need = sizeof(type) * n;			\
 71		ceph_decode_need(p, end, need, bad);		\
 72		*p += need;					\
 73	} while (0)
 74
 75#define __decode_and_drop_map(p, end, ktype, vtype, bad)	\
 76	do {							\
 77		u32 n;						\
 78		size_t need;					\
 79		ceph_decode_32_safe(p, end, n, bad);		\
 80		need = (sizeof(ktype) + sizeof(vtype)) * n;	\
 81		ceph_decode_need(p, end, need, bad);		\
 82		*p += need;					\
 83	} while (0)
 84
 85
 86static int __decode_and_drop_compat_set(void **p, void* end)
 87{
 88	int i;
 89	/* compat, ro_compat, incompat*/
 90	for (i = 0; i < 3; i++) {
 91		u32 n;
 92		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 93		/* mask */
 94		*p += sizeof(u64);
 95		/* names (map<u64, string>) */
 96		n = ceph_decode_32(p);
 97		while (n-- > 0) {
 98			u32 len;
 99			ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
100					 bad);
101			*p += sizeof(u64);
102			len = ceph_decode_32(p);
103			ceph_decode_need(p, end, len, bad);
104			*p += len;
105		}
106	}
107	return 0;
108bad:
109	return -1;
110}
111
112/*
113 * Decode an MDS map
114 *
115 * Ignore any fields we don't care about (there are quite a few of
116 * them).
117 */
118struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
119				       void *end, bool msgr2)
120{
121	struct ceph_client *cl = mdsc->fsc->client;
122	struct ceph_mdsmap *m;
123	const void *start = *p;
124	int i, j, n;
125	int err;
126	u8 mdsmap_v;
127	u16 mdsmap_ev;
128	u32 target;
129
130	m = kzalloc(sizeof(*m), GFP_NOFS);
131	if (!m)
132		return ERR_PTR(-ENOMEM);
133
134	ceph_decode_need(p, end, 1 + 1, bad);
135	mdsmap_v = ceph_decode_8(p);
136	*p += sizeof(u8);			/* mdsmap_cv */
137	if (mdsmap_v >= 4) {
138	       u32 mdsmap_len;
139	       ceph_decode_32_safe(p, end, mdsmap_len, bad);
140	       if (end < *p + mdsmap_len)
141		       goto bad;
142	       end = *p + mdsmap_len;
143	}
144
145	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
146	m->m_epoch = ceph_decode_32(p);
147	m->m_client_epoch = ceph_decode_32(p);
148	m->m_last_failure = ceph_decode_32(p);
149	m->m_root = ceph_decode_32(p);
150	m->m_session_timeout = ceph_decode_32(p);
151	m->m_session_autoclose = ceph_decode_32(p);
152	m->m_max_file_size = ceph_decode_64(p);
153	m->m_max_mds = ceph_decode_32(p);
154
155	/*
156	 * pick out the active nodes as the m_num_active_mds, the
157	 * m_num_active_mds maybe larger than m_max_mds when decreasing
158	 * the max_mds in cluster side, in other case it should less
159	 * than or equal to m_max_mds.
160	 */
161	m->m_num_active_mds = n = ceph_decode_32(p);
162
163	/*
164	 * the possible max rank, it maybe larger than the m_num_active_mds,
165	 * for example if the mds_max == 2 in the cluster, when the MDS(0)
166	 * was laggy and being replaced by a new MDS, we will temporarily
167	 * receive a new mds map with n_num_mds == 1 and the active MDS(1),
168	 * and the mds rank >= m_num_active_mds.
169	 */
170	m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
171
172	m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
173	if (!m->m_info)
174		goto nomem;
175
176	/* pick out active nodes from mds_info (state > 0) */
177	for (i = 0; i < n; i++) {
178		u64 global_id;
179		u32 namelen;
180		s32 mds, inc, state;
181		u8 info_v;
182		void *info_end = NULL;
183		struct ceph_entity_addr addr;
184		u32 num_export_targets;
185		void *pexport_targets = NULL;
186		struct ceph_timespec laggy_since;
187		struct ceph_mds_info *info;
188		bool laggy;
189
190		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
191		global_id = ceph_decode_64(p);
192		info_v= ceph_decode_8(p);
193		if (info_v >= 4) {
194			u32 info_len;
195			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
196			*p += sizeof(u8);	/* info_cv */
197			info_len = ceph_decode_32(p);
198			info_end = *p + info_len;
199			if (info_end > end)
200				goto bad;
201		}
202
203		ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
204		*p += sizeof(u64);
205		namelen = ceph_decode_32(p);  /* skip mds name */
206		*p += namelen;
207
208		ceph_decode_32_safe(p, end, mds, bad);
209		ceph_decode_32_safe(p, end, inc, bad);
210		ceph_decode_32_safe(p, end, state, bad);
 
 
 
 
211		*p += sizeof(u64);		/* state_seq */
212		if (info_v >= 8)
213			err = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
214		else
215			err = ceph_decode_entity_addr(p, end, &addr);
216		if (err)
217			goto corrupt;
218
219		ceph_decode_copy_safe(p, end, &laggy_since, sizeof(laggy_since),
220				      bad);
221		laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
222		*p += sizeof(u32);
223		ceph_decode_32_safe(p, end, namelen, bad);
224		*p += namelen;
225		if (info_v >= 2) {
226			ceph_decode_32_safe(p, end, num_export_targets, bad);
227			pexport_targets = *p;
228			*p += num_export_targets * sizeof(u32);
229		} else {
230			num_export_targets = 0;
231		}
232
233		if (info_end && *p != info_end) {
234			if (*p > info_end)
235				goto bad;
236			*p = info_end;
237		}
238
239		doutc(cl, "%d/%d %lld mds%d.%d %s %s%s\n", i+1, n, global_id,
240		      mds, inc, ceph_pr_addr(&addr),
241		      ceph_mds_state_name(state), laggy ? "(laggy)" : "");
 
 
242
243		if (mds < 0 || mds >= m->possible_max_rank) {
244			pr_warn_client(cl, "got incorrect mds(%d)\n", mds);
245			continue;
246		}
247
248		if (state <= 0) {
249			doutc(cl, "got incorrect state(%s)\n",
250			      ceph_mds_state_name(state));
251			continue;
252		}
253
254		info = &m->m_info[mds];
255		info->global_id = global_id;
256		info->state = state;
257		info->addr = addr;
258		info->laggy = laggy;
259		info->num_export_targets = num_export_targets;
260		if (num_export_targets) {
261			info->export_targets = kcalloc(num_export_targets,
262						       sizeof(u32), GFP_NOFS);
263			if (!info->export_targets)
264				goto nomem;
265			for (j = 0; j < num_export_targets; j++) {
266				target = ceph_decode_32(&pexport_targets);
267				info->export_targets[j] = target;
268			}
269		} else {
270			info->export_targets = NULL;
271		}
272	}
273
274	/* pg_pools */
275	ceph_decode_32_safe(p, end, n, bad);
276	m->m_num_data_pg_pools = n;
277	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
278	if (!m->m_data_pg_pools)
279		goto nomem;
280	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
281	for (i = 0; i < n; i++)
282		m->m_data_pg_pools[i] = ceph_decode_64(p);
283	m->m_cas_pg_pool = ceph_decode_64(p);
284	m->m_enabled = m->m_epoch > 1;
285
286	mdsmap_ev = 1;
287	if (mdsmap_v >= 2) {
288		ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
289	}
290	if (mdsmap_ev >= 3) {
291		if (__decode_and_drop_compat_set(p, end) < 0)
292			goto bad_ext;
293	}
294	/* metadata_pool */
295	if (mdsmap_ev < 5) {
296		__decode_and_drop_type(p, end, u32, bad_ext);
297	} else {
298		__decode_and_drop_type(p, end, u64, bad_ext);
299	}
300
301	/* created + modified + tableserver */
302	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
303	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
304	__decode_and_drop_type(p, end, u32, bad_ext);
305
306	/* in */
307	{
308		int num_laggy = 0;
309		ceph_decode_32_safe(p, end, n, bad_ext);
310		ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
311
312		for (i = 0; i < n; i++) {
313			s32 mds = ceph_decode_32(p);
314			if (mds >= 0 && mds < m->possible_max_rank) {
315				if (m->m_info[mds].laggy)
316					num_laggy++;
317			}
318		}
319		m->m_num_laggy = num_laggy;
320
321		if (n > m->possible_max_rank) {
322			void *new_m_info = krealloc(m->m_info,
323						    n * sizeof(*m->m_info),
324						    GFP_NOFS | __GFP_ZERO);
325			if (!new_m_info)
326				goto nomem;
327			m->m_info = new_m_info;
328		}
329		m->possible_max_rank = n;
330	}
331
332	/* inc */
333	__decode_and_drop_map(p, end, u32, u32, bad_ext);
334	/* up */
335	__decode_and_drop_map(p, end, u32, u64, bad_ext);
336	/* failed */
337	__decode_and_drop_set(p, end, u32, bad_ext);
338	/* stopped */
339	__decode_and_drop_set(p, end, u32, bad_ext);
340
341	if (mdsmap_ev >= 4) {
342		/* last_failure_osd_epoch */
343		__decode_and_drop_type(p, end, u32, bad_ext);
344	}
345	if (mdsmap_ev >= 6) {
346		/* ever_allowed_snaps */
347		__decode_and_drop_type(p, end, u8, bad_ext);
348		/* explicitly_allowed_snaps */
349		__decode_and_drop_type(p, end, u8, bad_ext);
350	}
351	if (mdsmap_ev >= 7) {
352		/* inline_data_enabled */
353		__decode_and_drop_type(p, end, u8, bad_ext);
354	}
355	if (mdsmap_ev >= 8) {
 
356		/* enabled */
357		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
358		/* fs_name */
359		ceph_decode_skip_string(p, end, bad_ext);
 
360	}
361	/* damaged */
362	if (mdsmap_ev >= 9) {
363		size_t need;
364		ceph_decode_32_safe(p, end, n, bad_ext);
365		need = sizeof(u32) * n;
366		ceph_decode_need(p, end, need, bad_ext);
367		*p += need;
368		m->m_damaged = n > 0;
369	} else {
370		m->m_damaged = false;
371	}
372	if (mdsmap_ev >= 17) {
373		/* balancer */
374		ceph_decode_skip_string(p, end, bad_ext);
375		/* standby_count_wanted */
376		ceph_decode_skip_32(p, end, bad_ext);
377		/* old_max_mds */
378		ceph_decode_skip_32(p, end, bad_ext);
379		/* min_compat_client */
380		ceph_decode_skip_8(p, end, bad_ext);
381		/* required_client_features */
382		ceph_decode_skip_set(p, end, 64, bad_ext);
383		/* bal_rank_mask */
384		ceph_decode_skip_string(p, end, bad_ext);
385	}
386	if (mdsmap_ev >= 18) {
387		ceph_decode_64_safe(p, end, m->m_max_xattr_size, bad_ext);
388	}
389bad_ext:
390	doutc(cl, "m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
391	      !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
392	*p = end;
393	doutc(cl, "success epoch %u\n", m->m_epoch);
394	return m;
395nomem:
396	err = -ENOMEM;
397	goto out_err;
398corrupt:
399	pr_err_client(cl, "corrupt mdsmap\n");
400	print_hex_dump(KERN_DEBUG, "mdsmap: ",
401		       DUMP_PREFIX_OFFSET, 16, 1,
402		       start, end - start, true);
403out_err:
404	ceph_mdsmap_destroy(m);
405	return ERR_PTR(err);
406bad:
407	err = -EINVAL;
408	goto corrupt;
409}
410
411void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
412{
413	int i;
414
415	if (m->m_info) {
416		for (i = 0; i < m->possible_max_rank; i++)
417			kfree(m->m_info[i].export_targets);
418		kfree(m->m_info);
419	}
420	kfree(m->m_data_pg_pools);
421	kfree(m);
422}
423
424bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
425{
426	int i, nr_active = 0;
427	if (!m->m_enabled)
428		return false;
429	if (m->m_damaged)
430		return false;
431	if (m->m_num_laggy == m->m_num_active_mds)
432		return false;
433	for (i = 0; i < m->possible_max_rank; i++) {
434		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
435			nr_active++;
436	}
437	return nr_active > 0;
438}