[mirror_ubuntu-zesty-kernel.git] / fs / ceph / mdsmap.c

#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_max_mds && m->m_info[0].state > 0)
		return 0;

	/* count */
	for (i = 0; i < m->m_max_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 == NULL)
		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_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
	if (m->m_info == NULL)
		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 || mds >= m->m_max_mds || state <= 0)
			continue;

		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 == NULL)
				goto nomem;
			for (j = 0; j < num_export_targets; j++)
				info->export_targets[j] =
				       ceph_decode_32(&pexport_targets);
		} 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->m_max_mds) {
				if (m->m_info[mds].laggy)
					num_laggy++;
			}
		}
		m->m_num_laggy = num_laggy;
	}

	/* 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_max_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_max_mds; i++) {
		if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
			nr_active++;
	}
	return nr_active > 0;
}
Commit	Line	Data
3d14c5d2	1	#include <linux/ceph/ceph_debug.h>
2f2dc053 SW	2
	3	#include <linux/bug.h>
	4	#include <linux/err.h>
	5	#include <linux/random.h>
	6	#include <linux/slab.h>
	7	#include <linux/types.h>
	8
3d14c5d2 YS	9	#include <linux/ceph/mdsmap.h>
	10	#include <linux/ceph/messenger.h>
	11	#include <linux/ceph/decode.h>
2f2dc053 SW	12
	13	#include "super.h"
	14
	15
	16	/*
	17	* choose a random mds that is "up" (i.e. has a state > 0), or -1.
	18	*/
	19	int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
	20	{
	21	int n = 0;
	22	int i;
a84cd293 SL	23
	24	/* special case for one mds */
	25	if (1 == m->m_max_mds && m->m_info[0].state > 0)
	26	return 0;
2f2dc053 SW	27
	28	/* count */
	29	for (i = 0; i < m->m_max_mds; i++)
	30	if (m->m_info[i].state > 0)
	31	n++;
	32	if (n == 0)
	33	return -1;
	34
	35	/* pick */
a84cd293	36	n = prandom_u32() % n;
2f2dc053 SW	37	i = 0;
	38	for (i = 0; n > 0; i++, n--)
	39	while (m->m_info[i].state <= 0)
	40	i++;
	41
	42	return i;
	43	}
	44
e9e427f0 YZ	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
2f2dc053 SW	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;
9ec7cab1	108	const void start = p;
2f2dc053 SW	109	int i, j, n;
2f2dc053 SW	110	int err = -EINVAL;
d463a43d	111	u8 mdsmap_v, mdsmap_cv;
e9e427f0	112	u16 mdsmap_ev;
2f2dc053 SW	113
	114	m = kzalloc(sizeof(*m), GFP_NOFS);
	115	if (m == NULL)
	116	return ERR_PTR(-ENOMEM);
	117
d463a43d YZ	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;
4f6a7e5e	127	}
2f2dc053 SW	128
2f2dc053 SW	129	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
c89136ea SW	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);
2f2dc053 SW	138
	139	m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
	140	if (m->m_info == NULL)
e9e427f0	141	goto nomem;
2f2dc053 SW	142
2f2dc053 SW	143	/* pick out active nodes from mds_info (state > 0) */
c89136ea	144	n = ceph_decode_32(p);
2f2dc053	145	for (i = 0; i < n; i++) {
94045e11	146	u64 global_id;
2f2dc053 SW	147	u32 namelen;
	148	s32 mds, inc, state;
	149	u64 state_seq;
d463a43d YZ	150	u8 info_v;
d463a43d YZ	151	void *info_end = NULL;
2f2dc053 SW	152	struct ceph_entity_addr addr;
	153	u32 num_export_targets;
	154	void *pexport_targets = NULL;
0deb01c9	155	struct ceph_timespec laggy_since;
6af86528	156	struct ceph_mds_info *info;
2f2dc053	157
d463a43d	158	ceph_decode_need(p, end, sizeof(u64) + 1, bad);
94045e11	159	global_id = ceph_decode_64(p);
d463a43d YZ	160	info_v= ceph_decode_8(p);
	161	if (info_v >= 4) {
	162	u32 info_len;
	163	u8 info_cv;
	164	ceph_decode_need(p, end, 1 + sizeof(u32), bad);
	165	info_cv = ceph_decode_8(p);
	166	info_len = ceph_decode_32(p);
	167	info_end = *p + info_len;
	168	if (info_end > end)
	169	goto bad;
	170	}
	171
	172	ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
94045e11	173	*p += sizeof(u64);
c89136ea	174	namelen = ceph_decode_32(p); /* skip mds name */
2f2dc053 SW	175	*p += namelen;
	176
	177	ceph_decode_need(p, end,
e251e288	178	4*sizeof(u32) + sizeof(u64) +
2f2dc053 SW	179	sizeof(addr) + sizeof(struct ceph_timespec),
2f2dc053 SW	180	bad);
c89136ea SW	181	mds = ceph_decode_32(p);
	182	inc = ceph_decode_32(p);
	183	state = ceph_decode_32(p);
	184	state_seq = ceph_decode_64(p);
94045e11 SW	185	ceph_decode_copy(p, &addr, sizeof(addr));
94045e11 SW	186	ceph_decode_addr(&addr);
0deb01c9	187	ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
2f2dc053 SW	188	*p += sizeof(u32);
2f2dc053 SW	189	ceph_decode_32_safe(p, end, namelen, bad);
e251e288	190	*p += namelen;
d463a43d	191	if (info_v >= 2) {
2f2dc053 SW	192	ceph_decode_32_safe(p, end, num_export_targets, bad);
2f2dc053 SW	193	pexport_targets = *p;
e251e288	194	p += num_export_targets sizeof(u32);
2f2dc053 SW	195	} else {
	196	num_export_targets = 0;
	197	}
	198
d463a43d YZ	199	if (info_end && *p != info_end) {
	200	if (*p > info_end)
	201	goto bad;
	202	*p = info_end;
	203	}
	204
94045e11	205	dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
3d14c5d2 YS	206	i+1, n, global_id, mds, inc,
3d14c5d2 YS	207	ceph_pr_addr(&addr.in_addr),
2f2dc053	208	ceph_mds_state_name(state));
6af86528 DC	209
	210	if (mds < 0 \|\| mds >= m->m_max_mds \|\| state <= 0)
	211	continue;
	212
	213	info = &m->m_info[mds];
	214	info->global_id = global_id;
	215	info->state = state;
	216	info->addr = addr;
	217	info->laggy = (laggy_since.tv_sec != 0 \|\|
	218	laggy_since.tv_nsec != 0);
	219	info->num_export_targets = num_export_targets;
	220	if (num_export_targets) {
	221	info->export_targets = kcalloc(num_export_targets,
	222	sizeof(u32), GFP_NOFS);
	223	if (info->export_targets == NULL)
e9e427f0	224	goto nomem;
6af86528 DC	225	for (j = 0; j < num_export_targets; j++)
	226	info->export_targets[j] =
	227	ceph_decode_32(&pexport_targets);
	228	} else {
	229	info->export_targets = NULL;
2f2dc053 SW	230	}
	231	}
	232
	233	/* pg_pools */
	234	ceph_decode_32_safe(p, end, n, bad);
	235	m->m_num_data_pg_pools = n;
4f6a7e5e	236	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
2f2dc053	237	if (!m->m_data_pg_pools)
e9e427f0	238	goto nomem;
4f6a7e5e	239	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
2f2dc053	240	for (i = 0; i < n; i++)
4f6a7e5e SW	241	m->m_data_pg_pools[i] = ceph_decode_64(p);
4f6a7e5e SW	242	m->m_cas_pg_pool = ceph_decode_64(p);
e9e427f0 YZ	243	m->m_enabled = m->m_epoch > 1;
	244
	245	mdsmap_ev = 1;
	246	if (mdsmap_v >= 2) {
	247	ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
	248	}
	249	if (mdsmap_ev >= 3) {
	250	if (__decode_and_drop_compat_set(p, end) < 0)
	251	goto bad_ext;
	252	}
	253	/* metadata_pool */
	254	if (mdsmap_ev < 5) {
	255	__decode_and_drop_type(p, end, u32, bad_ext);
	256	} else {
	257	__decode_and_drop_type(p, end, u64, bad_ext);
	258	}
2f2dc053	259
e9e427f0 YZ	260	/* created + modified + tableserver */
	261	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
	262	__decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
	263	__decode_and_drop_type(p, end, u32, bad_ext);
	264
	265	/* in */
	266	{
	267	int num_laggy = 0;
	268	ceph_decode_32_safe(p, end, n, bad_ext);
	269	ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
	270
	271	for (i = 0; i < n; i++) {
	272	s32 mds = ceph_decode_32(p);
	273	if (mds >= 0 && mds < m->m_max_mds) {
	274	if (m->m_info[mds].laggy)
	275	num_laggy++;
	276	}
	277	}
	278	m->m_num_laggy = num_laggy;
	279	}
	280
	281	/* inc */
	282	__decode_and_drop_map(p, end, u32, u32, bad_ext);
	283	/* up */
	284	__decode_and_drop_map(p, end, u32, u64, bad_ext);
	285	/* failed */
	286	__decode_and_drop_set(p, end, u32, bad_ext);
	287	/* stopped */
	288	__decode_and_drop_set(p, end, u32, bad_ext);
	289
	290	if (mdsmap_ev >= 4) {
	291	/* last_failure_osd_epoch */
	292	__decode_and_drop_type(p, end, u32, bad_ext);
	293	}
	294	if (mdsmap_ev >= 6) {
	295	/* ever_allowed_snaps */
	296	__decode_and_drop_type(p, end, u8, bad_ext);
	297	/* explicitly_allowed_snaps */
	298	__decode_and_drop_type(p, end, u8, bad_ext);
	299	}
	300	if (mdsmap_ev >= 7) {
	301	/* inline_data_enabled */
	302	__decode_and_drop_type(p, end, u8, bad_ext);
	303	}
	304	if (mdsmap_ev >= 8) {
	305	u32 name_len;
	306	/* enabled */
	307	ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
	308	ceph_decode_32_safe(p, end, name_len, bad_ext);
	309	ceph_decode_need(p, end, name_len, bad_ext);
	310	*p += name_len;
	311	}
	312	/* damaged */
	313	if (mdsmap_ev >= 9) {
	314	size_t need;
	315	ceph_decode_32_safe(p, end, n, bad_ext);
	316	need = sizeof(u32) * n;
	317	ceph_decode_need(p, end, need, bad_ext);
	318	*p += need;
	319	m->m_damaged = n > 0;
	320	} else {
	321	m->m_damaged = false;
	322	}
	323	bad_ext:
d463a43d	324	*p = end;
2f2dc053 SW	325	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
2f2dc053 SW	326	return m;
e9e427f0	327	nomem:
2f2dc053	328	err = -ENOMEM;
e9e427f0	329	goto out_err;
2f2dc053 SW	330	bad:
2f2dc053 SW	331	pr_err("corrupt mdsmap\n");
9ec7cab1 SW	332	print_hex_dump(KERN_DEBUG, "mdsmap: ",
	333	DUMP_PREFIX_OFFSET, 16, 1,
	334	start, end - start, true);
e9e427f0	335	out_err:
2f2dc053	336	ceph_mdsmap_destroy(m);
c213b50b	337	return ERR_PTR(err);
2f2dc053 SW	338	}
	339
	340	void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
	341	{
	342	int i;
	343
	344	for (i = 0; i < m->m_max_mds; i++)
	345	kfree(m->m_info[i].export_targets);
	346	kfree(m->m_info);
	347	kfree(m->m_data_pg_pools);
	348	kfree(m);
	349	}
e9e427f0 YZ	350
	351	bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
	352	{
	353	int i, nr_active = 0;
	354	if (!m->m_enabled)
	355	return false;
	356	if (m->m_damaged)
	357	return false;
	358	if (m->m_num_laggy > 0)
	359	return false;
	360	for (i = 0; i < m->m_max_mds; i++) {
	361	if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
	362	nr_active++;
	363	}
	364	return nr_active > 0;
	365	}