linux/fs/ceph/mdsmap.c
Xiubo Li d517b3983d ceph: reconnect to the export targets on new mdsmaps
In the case where the export MDS has crashed just after the EImportStart
journal is flushed, a standby MDS takes over for it and when replaying
the EImportStart journal the MDS will wait the client to reconnect. That
may never happen because the client may not have registered or opened
the sessions yet.

When receiving a new map, ensure we reconnect to valid export targets as
well if their sessions don't exist yet.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2021-09-02 22:49:17 +02:00

427 lines
10 KiB
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"
#define CEPH_MDS_IS_READY(i, ignore_laggy) \
(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
{
int n = 0;
int i, j;
/* count */
for (i = 0; i < m->possible_max_rank; i++)
if (CEPH_MDS_IS_READY(i, ignore_laggy))
n++;
if (n == 0)
return -1;
/* pick */
n = prandom_u32() % n;
for (j = 0, i = 0; i < m->possible_max_rank; i++) {
if (CEPH_MDS_IS_READY(i, ignore_laggy))
j++;
if (j > n)
break;
}
return i;
}
/*
* 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 mds;
mds = __mdsmap_get_random_mds(m, false);
if (mds == m->possible_max_rank || mds == -1)
mds = __mdsmap_get_random_mds(m, true);
return mds == m->possible_max_rank ? -1 : mds;
}
#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, bool msgr2)
{
struct ceph_mdsmap *m;
const void *start = *p;
int i, j, n;
int err;
u8 mdsmap_v;
u16 mdsmap_ev;
u32 target;
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);
*p += sizeof(u8); /* mdsmap_cv */
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);
/*
* pick out the active nodes as the m_num_active_mds, the
* m_num_active_mds maybe larger than m_max_mds when decreasing
* the max_mds in cluster side, in other case it should less
* than or equal to m_max_mds.
*/
m->m_num_active_mds = n = ceph_decode_32(p);
/*
* the possible max rank, it maybe larger than the m_num_active_mds,
* for example if the mds_max == 2 in the cluster, when the MDS(0)
* was laggy and being replaced by a new MDS, we will temporarily
* receive a new mds map with n_num_mds == 1 and the active MDS(1),
* and the mds rank >= m_num_active_mds.
*/
m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
if (!m->m_info)
goto nomem;
/* pick out active nodes from mds_info (state > 0) */
for (i = 0; i < n; i++) {
u64 global_id;
u32 namelen;
s32 mds, inc, state;
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;
bool laggy;
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;
ceph_decode_need(p, end, 1 + sizeof(u32), bad);
*p += sizeof(u8); /* info_cv */
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_32_safe(p, end, mds, bad);
ceph_decode_32_safe(p, end, inc, bad);
ceph_decode_32_safe(p, end, state, bad);
*p += sizeof(u64); /* state_seq */
if (info_v >= 8)
err = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
else
err = ceph_decode_entity_addr(p, end, &addr);
if (err)
goto corrupt;
ceph_decode_copy_safe(p, end, &laggy_since, sizeof(laggy_since),
bad);
laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
*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%s\n",
i+1, n, global_id, mds, inc,
ceph_pr_addr(&addr),
ceph_mds_state_name(state),
laggy ? "(laggy)" : "");
if (mds < 0 || mds >= m->possible_max_rank) {
pr_warn("mdsmap_decode got incorrect mds(%d)\n", mds);
continue;
}
if (state <= 0) {
dout("mdsmap_decode got incorrect state(%s)\n",
ceph_mds_state_name(state));
continue;
}
info = &m->m_info[mds];
info->global_id = global_id;
info->state = state;
info->addr = addr;
info->laggy = laggy;
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++) {
target = ceph_decode_32(&pexport_targets);
if (target >= m->possible_max_rank) {
err = -EIO;
goto corrupt;
}
info->export_targets[j] = target;
}
} 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->possible_max_rank) {
if (m->m_info[mds].laggy)
num_laggy++;
}
}
m->m_num_laggy = num_laggy;
if (n > m->possible_max_rank) {
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->possible_max_rank = 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:
dout("mdsmap_decode m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
!!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
*p = end;
dout("mdsmap_decode success epoch %u\n", m->m_epoch);
return m;
nomem:
err = -ENOMEM;
goto out_err;
corrupt:
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);
bad:
err = -EINVAL;
goto corrupt;
}
void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
{
int i;
if (m->m_info) {
for (i = 0; i < m->possible_max_rank; 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 == m->m_num_active_mds)
return false;
for (i = 0; i < m->possible_max_rank; i++) {
if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
nr_active++;
}
return nr_active > 0;
}