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// 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, j;
/* 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;
for (j = 0, i = 0; i < m->m_num_mds; i++) {
if (m->m_info[i].state > 0)
j++;
if (j > n)
break;
}
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;
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);
err = ceph_decode_entity_addr(p, end, &addr);
if (err)
goto corrupt;
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),
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(
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