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linux-next/fs/afs/vlclient.c
David Howells 8b2a464ced afs: Add an address list concept
Add an RCU replaceable address list structure to hold a list of server
addresses.  The list also holds the

To this end:

 (1) A cell's VL server address list can be loaded directly via insmod or
     echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB
     or SRV records.

 (2) Anyone wanting to use a cell's VL server address must wait until the
     cell record comes online and has tried to obtain some addresses.

 (3) An FS server's address list, for the moment, has a single entry that
     is the key to the server list.  This will change in the future when a
     server is instead keyed on its UUID and the VL.GetAddrsU operation is
     used.

 (4) An 'address cursor' concept is introduced to handle iteration through
     the address list.  This is passed to the afs_make_call() as, in the
     future, stuff (such as abort code) that doesn't outlast the call will
     be returned in it.

In the future, we might want to annotate the list with information about
how each address fares.  We might then want to propagate such annotations
over address list replacement.

Whilst we're at it, we allow IPv6 addresses to be specified in
colon-delimited lists by enclosing them in square brackets.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13 15:38:18 +00:00

184 lines
4.6 KiB
C

/* AFS Volume Location Service client
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/sched.h>
#include "afs_fs.h"
#include "internal.h"
/*
* deliver reply data to a VL.GetEntryByXXX call
*/
static int afs_deliver_vl_get_entry_by_xxx(struct afs_call *call)
{
struct afs_cache_vlocation *entry;
__be32 *bp;
u32 tmp;
int loop, ret;
_enter("");
ret = afs_transfer_reply(call);
if (ret < 0)
return ret;
/* unmarshall the reply once we've received all of it */
entry = call->reply[0];
bp = call->buffer;
for (loop = 0; loop < 64; loop++)
entry->name[loop] = ntohl(*bp++);
entry->name[loop] = 0;
bp++; /* final NUL */
bp++; /* type */
entry->nservers = ntohl(*bp++);
for (loop = 0; loop < 8; loop++) {
entry->servers[loop].srx_family = AF_RXRPC;
entry->servers[loop].srx_service = FS_SERVICE;
entry->servers[loop].transport_type = SOCK_DGRAM;
entry->servers[loop].transport_len = sizeof(entry->servers[loop].transport.sin6);
entry->servers[loop].transport.sin6.sin6_family = AF_INET6;
entry->servers[loop].transport.sin6.sin6_port = htons(AFS_FS_PORT);
entry->servers[loop].transport.sin6.sin6_flowinfo = 0;
entry->servers[loop].transport.sin6.sin6_scope_id = 0;
entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[0] = 0;
entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[1] = 0;
entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[3] = *bp++;
}
bp += 8; /* partition IDs */
for (loop = 0; loop < 8; loop++) {
tmp = ntohl(*bp++);
entry->srvtmask[loop] = 0;
if (tmp & AFS_VLSF_RWVOL)
entry->srvtmask[loop] |= AFS_VOL_VTM_RW;
if (tmp & AFS_VLSF_ROVOL)
entry->srvtmask[loop] |= AFS_VOL_VTM_RO;
if (tmp & AFS_VLSF_BACKVOL)
entry->srvtmask[loop] |= AFS_VOL_VTM_BAK;
}
entry->vid[0] = ntohl(*bp++);
entry->vid[1] = ntohl(*bp++);
entry->vid[2] = ntohl(*bp++);
bp++; /* clone ID */
tmp = ntohl(*bp++); /* flags */
entry->vidmask = 0;
if (tmp & AFS_VLF_RWEXISTS)
entry->vidmask |= AFS_VOL_VTM_RW;
if (tmp & AFS_VLF_ROEXISTS)
entry->vidmask |= AFS_VOL_VTM_RO;
if (tmp & AFS_VLF_BACKEXISTS)
entry->vidmask |= AFS_VOL_VTM_BAK;
if (!entry->vidmask)
return -EBADMSG;
_leave(" = 0 [done]");
return 0;
}
/*
* VL.GetEntryByName operation type
*/
static const struct afs_call_type afs_RXVLGetEntryByName = {
.name = "VL.GetEntryByName",
.deliver = afs_deliver_vl_get_entry_by_xxx,
.destructor = afs_flat_call_destructor,
};
/*
* VL.GetEntryById operation type
*/
static const struct afs_call_type afs_RXVLGetEntryById = {
.name = "VL.GetEntryById",
.deliver = afs_deliver_vl_get_entry_by_xxx,
.destructor = afs_flat_call_destructor,
};
/*
* dispatch a get volume entry by name operation
*/
int afs_vl_get_entry_by_name(struct afs_net *net,
struct afs_addr_cursor *ac,
struct key *key,
const char *volname,
struct afs_cache_vlocation *entry,
bool async)
{
struct afs_call *call;
size_t volnamesz, reqsz, padsz;
__be32 *bp;
_enter("");
volnamesz = strlen(volname);
padsz = (4 - (volnamesz & 3)) & 3;
reqsz = 8 + volnamesz + padsz;
call = afs_alloc_flat_call(net, &afs_RXVLGetEntryByName, reqsz, 384);
if (!call)
return -ENOMEM;
call->key = key;
call->reply[0] = entry;
/* marshall the parameters */
bp = call->request;
*bp++ = htonl(VLGETENTRYBYNAME);
*bp++ = htonl(volnamesz);
memcpy(bp, volname, volnamesz);
if (padsz > 0)
memset((void *) bp + volnamesz, 0, padsz);
/* initiate the call */
return afs_make_call(ac, call, GFP_KERNEL, async);
}
/*
* dispatch a get volume entry by ID operation
*/
int afs_vl_get_entry_by_id(struct afs_net *net,
struct afs_addr_cursor *ac,
struct key *key,
afs_volid_t volid,
afs_voltype_t voltype,
struct afs_cache_vlocation *entry,
bool async)
{
struct afs_call *call;
__be32 *bp;
_enter("");
call = afs_alloc_flat_call(net, &afs_RXVLGetEntryById, 12, 384);
if (!call)
return -ENOMEM;
call->key = key;
call->reply[0] = entry;
/* marshall the parameters */
bp = call->request;
*bp++ = htonl(VLGETENTRYBYID);
*bp++ = htonl(volid);
*bp = htonl(voltype);
/* initiate the call */
return afs_make_call(ac, call, GFP_KERNEL, async);
}