// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/ceph/ceph_features.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/libceph.h>
#include <linux/ceph/debugfs.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/auth.h>
/*
* Interact with Ceph monitor cluster. Handle requests for new map
* versions, and periodically resend as needed. Also implement
* statfs() and umount().
*
* A small cluster of Ceph "monitors" are responsible for managing critical
* cluster configuration and state information. An odd number (e.g., 3, 5)
* of cmon daemons use a modified version of the Paxos part-time parliament
* algorithm to manage the MDS map (mds cluster membership), OSD map, and
* list of clients who have mounted the file system.
*
* We maintain an open, active session with a monitor at all times in order to
* receive timely MDSMap updates. We periodically send a keepalive byte on the
* TCP socket to ensure we detect a failure. If the connection does break, we
* randomly hunt for a new monitor. Once the connection is reestablished, we
* resend any outstanding requests.
*/
static const struct ceph_connection_operations mon_con_ops;
static int __validate_auth(struct ceph_mon_client *monc);
/*
* Decode a monmap blob (e.g., during mount).
*/
static struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
{
struct ceph_monmap *m = NULL;
int i, err = -EINVAL;
struct ceph_fsid fsid;
u32 epoch, num_mon;
u32 len;
ceph_decode_32_safe(&p, end, len, bad);
ceph_decode_need(&p, end, len, bad);
dout("monmap_decode %p %p len %d (%d)\n", p, end, len, (int)(end-p));
p += sizeof(u16); /* skip version */
ceph_decode_need(&p, end, sizeof(fsid) + 2*sizeof(u32), bad);
ceph_decode_copy(&p, &fsid, sizeof(fsid));
epoch = ceph_decode_32(&p);
num_mon = ceph_decode_32(&p);
if (num_mon > CEPH_MAX_MON)
goto bad;
m = kmalloc(struct_size(m, mon_inst, num_mon), GFP_NOFS);
if (m == NULL)
return ERR_PTR(-ENOMEM);
