[linux-block.git] / fs / ceph / mdsmap.c

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

#include "super.h"


/*
 * 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 n = 0;
	int i;

	/* special case for one mds */
	if (1 == m->m_num_mds && m->m_info[0].state > 0)
		return 0;

	/* count */
	for (i = 0; i < m->m_num_mds; i++)
		if (m->m_info[i].state > 0)
			n++;
	if (n == 0)
		return -1;

	/* pick */
	n = prandom_u32() % n;
	i = 0;
	for (i = 0; n > 0; i++, n--)
		while (m->m_info[i].state <= 0)
			i++;

	return i;
}

#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(void **p, void *end)
{
	struct ceph_mdsmap *m;
	const void *start = *p;
	int i, j, n;
	int err = -EINVAL;
	u8 mdsmap_v, mdsmap_cv;
	u16 mdsmap_ev;

	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);
	mdsmap_cv = ceph_decode_8(p);
	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);
	m->m_num_mds = m->m_max_mds;

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

	/* pick out active nodes from mds_info (state > 0) */
	n = ceph_decode_32(p);
	for (i = 0; i < n; i++) {
		u64 global_id;
		u32 namelen;
		s32 mds, inc, state;
		u64 state_seq;
		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;

		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;
			u8 info_cv;
			ceph_decode_need(p, end, 1 + sizeof(u32), bad);
			info_cv = ceph_decode_8(p);
			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_need(p, end,
				 4*sizeof(u32) + sizeof(u64) +
				 sizeof(addr) + sizeof(struct ceph_timespec),
				 bad);
		mds = ceph_decode_32(p);
		inc = ceph_decode_32(p);
		state = ceph_decode_32(p);
		state_seq = ceph_decode_64(p);
		ceph_decode_copy(p, &addr, sizeof(addr));
		ceph_decode_addr(&addr);
		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
		*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;
		}

		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
		     i+1, n, global_id, mds, inc,
		     ceph_pr_addr(&addr.in_addr),
		     ceph_mds_state_name(state));

		if (mds < 0 || state <= 0)
			continue;

		if (mds >= m->m_num_mds) {
			int new_num = max(mds + 1, m->m_num_mds * 2);
			void *new_m_info = krealloc(m->m_info,
						new_num * sizeof(*m->m_info),
						GFP_NOFS | __GFP_ZERO);
			if (!new_m_info)
				goto nomem;
			m->m_info = new_m_info;
			m->m_num_mds = new_num;
		}

		info = &m->m_info[mds];
		info->global_id = global_id;
		info->state = state;
		info->addr = addr;
		info->laggy = (laggy_since.tv_sec != 0 ||
			       laggy_since.tv_nsec != 0);
		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++)
				info->export_targets[j] =
				       ceph_decode_32(&pexport_targets);
		} else {
			info->export_targets = NULL;
		}
	}
	if (m->m_num_mds > m->m_max_mds) {
		/* find max up mds */
		for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
			if (i == 0 || m->m_info[i-1].state > 0)
				break;
		}
		m->m_num_mds = i;
	}

	/* 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->m_num_mds) {
				if (m->m_info[mds].laggy)
					num_laggy++;
			}
		}
		m->m_num_laggy = num_laggy;

		if (n > m->m_num_mds) {
			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->m_num_mds = 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) {
		u32 name_len;
		/* enabled */
		ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
		ceph_decode_32_safe(p, end, name_len, bad_ext);
		ceph_decode_need(p, end, name_len, bad_ext);
		*p += name_len;
	}
	/* 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;
	}
bad_ext:
	*p = end;
	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
	return m;
nomem:
	err = -ENOMEM;
	goto out_err;
bad:
	pr_err("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);
}

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

	for (i = 0; i < m->m_num_mds; 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 > 0)
		return false;
	for (i = 0; i < m->m_num_mds; i++) {
		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
			nr_active++;
	}
	return nr_active > 0;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
3d14c5d2	2	#include <linux/ceph/ceph_debug.h>
2f2dc053 SW	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
3d14c5d2 YS	10	#include <linux/ceph/mdsmap.h>
	11	#include <linux/ceph/messenger.h>
	12	#include <linux/ceph/decode.h>
2f2dc053 SW	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;
a84cd293 SL	24
a84cd293 SL	25	/* special case for one mds */
76201b63	26	if (1 == m->m_num_mds && m->m_info[0].state > 0)
a84cd293	27	return 0;
2f2dc053 SW	28
2f2dc053 SW	29	/* count */
76201b63	30	for (i = 0; i < m->m_num_mds; i++)
2f2dc053 SW	31	if (m->m_info[i].state > 0)
	32	n++;
	33	if (n == 0)
	34	return -1;
	35
	36	/* pick */
a84cd293	37	n = prandom_u32() % n;
2f2dc053 SW	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
e9e427f0 YZ	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
	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
2f2dc053 SW	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	*/
	106	struct ceph_mdsmap ceph_mdsmap_decode(void p, void end)
	107	{
	108	struct ceph_mdsmap *m;
9ec7cab1	109	const void start = p;
2f2dc053 SW	110	int i, j, n;
2f2dc053 SW	111	int err = -EINVAL;
d463a43d	112	u8 mdsmap_v, mdsmap_cv;
e9e427f0	113	u16 mdsmap_ev;
2f2dc053 SW	114
2f2dc053 SW	115	m = kzalloc(sizeof(*m), GFP_NOFS);
d37b1d99	116	if (!m)
2f2dc053 SW	117	return ERR_PTR(-ENOMEM);
2f2dc053 SW	118
d463a43d YZ	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;
4f6a7e5e	128	}
2f2dc053 SW	129
2f2dc053 SW	130	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
c89136ea SW	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);
76201b63	139	m->m_num_mds = m->m_max_mds;
2f2dc053	140
76201b63	141	m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
d37b1d99	142	if (!m->m_info)
e9e427f0	143	goto nomem;
2f2dc053 SW	144
2f2dc053 SW	145	/* pick out active nodes from mds_info (state > 0) */
c89136ea	146	n = ceph_decode_32(p);
2f2dc053	147	for (i = 0; i < n; i++) {
94045e11	148	u64 global_id;
2f2dc053 SW	149	u32 namelen;
	150	s32 mds, inc, state;
	151	u64 state_seq;
d463a43d YZ	152	u8 info_v;
d463a43d YZ	153	void *info_end = NULL;
2f2dc053 SW	154	struct ceph_entity_addr addr;
	155	u32 num_export_targets;
	156	void *pexport_targets = NULL;
0deb01c9	157	struct ceph_timespec laggy_since;
6af86528	158	struct ceph_mds_info *info;
2f2dc053	159
d463a43d	160	ceph_decode_need(p, end, sizeof(u64) + 1, bad);
94045e11	161	global_id = ceph_decode_64(p);
d463a43d YZ	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);
94045e11	175	*p += sizeof(u64);
c89136ea	176	namelen = ceph_decode_32(p); /* skip mds name */
2f2dc053 SW	177	*p += namelen;
	178
	179	ceph_decode_need(p, end,
e251e288	180	4*sizeof(u32) + sizeof(u64) +
2f2dc053 SW	181	sizeof(addr) + sizeof(struct ceph_timespec),
2f2dc053 SW	182	bad);
c89136ea SW	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);
94045e11 SW	187	ceph_decode_copy(p, &addr, sizeof(addr));
94045e11 SW	188	ceph_decode_addr(&addr);
0deb01c9	189	ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
2f2dc053 SW	190	*p += sizeof(u32);
2f2dc053 SW	191	ceph_decode_32_safe(p, end, namelen, bad);
e251e288	192	*p += namelen;
d463a43d	193	if (info_v >= 2) {
2f2dc053 SW	194	ceph_decode_32_safe(p, end, num_export_targets, bad);
2f2dc053 SW	195	pexport_targets = *p;
e251e288	196	p += num_export_targets sizeof(u32);
2f2dc053 SW	197	} else {
	198	num_export_targets = 0;
	199	}
	200
d463a43d YZ	201	if (info_end && *p != info_end) {
	202	if (*p > info_end)
	203	goto bad;
	204	*p = info_end;
	205	}
	206
94045e11	207	dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
3d14c5d2 YS	208	i+1, n, global_id, mds, inc,
3d14c5d2 YS	209	ceph_pr_addr(&addr.in_addr),
2f2dc053	210	ceph_mds_state_name(state));
6af86528	211
76201b63	212	if (mds < 0 \|\| state <= 0)
6af86528 DC	213	continue;
6af86528 DC	214
76201b63 YZ	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
6af86528 DC	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);
d37b1d99	236	if (!info->export_targets)
e9e427f0	237	goto nomem;
6af86528 DC	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;
2f2dc053 SW	243	}
2f2dc053 SW	244	}
76201b63 YZ	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	}
2f2dc053 SW	253
	254	/* pg_pools */
	255	ceph_decode_32_safe(p, end, n, bad);
	256	m->m_num_data_pg_pools = n;
4f6a7e5e	257	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
2f2dc053	258	if (!m->m_data_pg_pools)
e9e427f0	259	goto nomem;
4f6a7e5e	260	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
2f2dc053	261	for (i = 0; i < n; i++)
4f6a7e5e SW	262	m->m_data_pg_pools[i] = ceph_decode_64(p);
4f6a7e5e SW	263	m->m_cas_pg_pool = ceph_decode_64(p);
e9e427f0 YZ	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	}
2f2dc053	280
e9e427f0 YZ	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);
76201b63	294	if (mds >= 0 && mds < m->m_num_mds) {
e9e427f0 YZ	295	if (m->m_info[mds].laggy)
	296	num_laggy++;
	297	}
	298	}
	299	m->m_num_laggy = num_laggy;
76201b63 YZ	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;
e9e427f0 YZ	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:
d463a43d	355	*p = end;
2f2dc053 SW	356	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
2f2dc053 SW	357	return m;
e9e427f0	358	nomem:
2f2dc053	359	err = -ENOMEM;
e9e427f0	360	goto out_err;
2f2dc053 SW	361	bad:
2f2dc053 SW	362	pr_err("corrupt mdsmap\n");
9ec7cab1 SW	363	print_hex_dump(KERN_DEBUG, "mdsmap: ",
	364	DUMP_PREFIX_OFFSET, 16, 1,
	365	start, end - start, true);
e9e427f0	366	out_err:
2f2dc053	367	ceph_mdsmap_destroy(m);
c213b50b	368	return ERR_PTR(err);
2f2dc053 SW	369	}
	370
	371	void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
	372	{
	373	int i;
	374
76201b63	375	for (i = 0; i < m->m_num_mds; i++)
2f2dc053 SW	376	kfree(m->m_info[i].export_targets);
	377	kfree(m->m_info);
	378	kfree(m->m_data_pg_pools);
	379	kfree(m);
	380	}
e9e427f0 YZ	381
	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;
76201b63	391	for (i = 0; i < m->m_num_mds; i++) {
e9e427f0 YZ	392	if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
	393	nr_active++;
	394	}
	395	return nr_active > 0;
	396	}