linux/fs/afs/fsclient.c

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/* AFS File Server client stubs
*
* Copyright (C) 2002, 2007 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/init.h>
#include <linux/sched.h>
#include <linux/circ_buf.h>
#include "internal.h"
#include "afs_fs.h"
/*
* decode an AFSFetchStatus block
*/
static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
struct afs_vnode *vnode)
{
const __be32 *bp = *_bp;
umode_t mode;
u64 data_version;
u32 changed = 0; /* becomes non-zero if ctime-type changes seen */
#define EXTRACT(DST) \
do { \
u32 x = ntohl(*bp++); \
changed |= DST - x; \
DST = x; \
} while (0)
vnode->status.if_version = ntohl(*bp++);
EXTRACT(vnode->status.type);
vnode->status.nlink = ntohl(*bp++);
EXTRACT(vnode->status.size);
data_version = ntohl(*bp++);
EXTRACT(vnode->status.author);
EXTRACT(vnode->status.owner);
EXTRACT(vnode->status.caller_access); /* call ticket dependent */
EXTRACT(vnode->status.anon_access);
EXTRACT(vnode->status.mode);
vnode->status.parent.vid = vnode->fid.vid;
EXTRACT(vnode->status.parent.vnode);
EXTRACT(vnode->status.parent.unique);
bp++; /* seg size */
vnode->status.mtime_client = ntohl(*bp++);
vnode->status.mtime_server = ntohl(*bp++);
bp++; /* group */
bp++; /* sync counter */
data_version |= (u64) ntohl(*bp++) << 32;
bp++; /* spare2 */
bp++; /* spare3 */
bp++; /* spare4 */
*_bp = bp;
if (changed) {
_debug("vnode changed");
set_bit(AFS_VNODE_CHANGED, &vnode->flags);
vnode->vfs_inode.i_uid = vnode->status.owner;
vnode->vfs_inode.i_size = vnode->status.size;
vnode->vfs_inode.i_version = vnode->fid.unique;
vnode->status.mode &= S_IALLUGO;
mode = vnode->vfs_inode.i_mode;
mode &= ~S_IALLUGO;
mode |= vnode->status.mode;
vnode->vfs_inode.i_mode = mode;
}
_debug("vnode time %lx, %lx",
vnode->status.mtime_client, vnode->status.mtime_server);
vnode->vfs_inode.i_ctime.tv_sec = vnode->status.mtime_server;
vnode->vfs_inode.i_mtime = vnode->vfs_inode.i_ctime;
vnode->vfs_inode.i_atime = vnode->vfs_inode.i_ctime;
if (vnode->status.data_version != data_version) {
_debug("vnode modified %llx", data_version);
vnode->status.data_version = data_version;
set_bit(AFS_VNODE_MODIFIED, &vnode->flags);
set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
}
}
/*
* decode an AFSCallBack block
*/
static void xdr_decode_AFSCallBack(const __be32 **_bp, struct afs_vnode *vnode)
{
const __be32 *bp = *_bp;
vnode->cb_version = ntohl(*bp++);
vnode->cb_expiry = ntohl(*bp++);
vnode->cb_type = ntohl(*bp++);
vnode->cb_expires = vnode->cb_expiry + get_seconds();
*_bp = bp;
}
/*
* decode an AFSVolSync block
*/
static void xdr_decode_AFSVolSync(const __be32 **_bp,
struct afs_volsync *volsync)
{
const __be32 *bp = *_bp;
volsync->creation = ntohl(*bp++);
bp++; /* spare2 */
bp++; /* spare3 */
bp++; /* spare4 */
bp++; /* spare5 */
bp++; /* spare6 */
*_bp = bp;
}
/*
* deliver reply data to an FS.FetchStatus
*/
static int afs_deliver_fs_fetch_status(struct afs_call *call,
struct sk_buff *skb, bool last)
{
const __be32 *bp;
_enter(",,%u", last);
afs_transfer_reply(call, skb);
if (!last)
return 0;
if (call->reply_size != call->reply_max)
return -EBADMSG;
/* unmarshall the reply once we've received all of it */
bp = call->buffer;
xdr_decode_AFSFetchStatus(&bp, call->reply);
xdr_decode_AFSCallBack(&bp, call->reply);
if (call->reply2)
xdr_decode_AFSVolSync(&bp, call->reply2);
_leave(" = 0 [done]");
return 0;
}
/*
* FS.FetchStatus operation type
*/
static const struct afs_call_type afs_RXFSFetchStatus = {
.deliver = afs_deliver_fs_fetch_status,
.abort_to_error = afs_abort_to_error,
.destructor = afs_flat_call_destructor,
};
/*
* fetch the status information for a file
*/
int afs_fs_fetch_file_status(struct afs_server *server,
struct afs_vnode *vnode,
struct afs_volsync *volsync,
const struct afs_wait_mode *wait_mode)
{
struct afs_call *call;
__be32 *bp;
_enter("");
call = afs_alloc_flat_call(&afs_RXFSFetchStatus, 16, 120);
if (!call)
return -ENOMEM;
call->reply = vnode;
call->reply2 = volsync;
call->service_id = FS_SERVICE;
call->port = htons(AFS_FS_PORT);
/* marshall the parameters */
bp = call->request;
bp[0] = htonl(FSFETCHSTATUS);
bp[1] = htonl(vnode->fid.vid);
bp[2] = htonl(vnode->fid.vnode);
bp[3] = htonl(vnode->fid.unique);
return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
}
/*
* deliver reply data to an FS.FetchData
*/
static int afs_deliver_fs_fetch_data(struct afs_call *call,
struct sk_buff *skb, bool last)
{
const __be32 *bp;
struct page *page;
void *buffer;
int ret;
_enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
switch (call->unmarshall) {
case 0:
call->offset = 0;
call->unmarshall++;
/* extract the returned data length */
case 1:
_debug("extract data length");
ret = afs_extract_data(call, skb, last, &call->tmp, 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
call->count = ntohl(call->tmp);
_debug("DATA length: %u", call->count);
if (call->count > PAGE_SIZE)
return -EBADMSG;
call->offset = 0;
call->unmarshall++;
if (call->count < PAGE_SIZE) {
buffer = kmap_atomic(call->reply3, KM_USER0);
memset(buffer + PAGE_SIZE - call->count, 0,
call->count);
kunmap_atomic(buffer, KM_USER0);
}
/* extract the returned data */
case 2:
_debug("extract data");
page = call->reply3;
buffer = kmap_atomic(page, KM_USER0);
ret = afs_extract_data(call, skb, last, buffer, call->count);
kunmap_atomic(buffer, KM_USER0);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
call->offset = 0;
call->unmarshall++;
/* extract the metadata */
case 3:
ret = afs_extract_data(call, skb, last, call->buffer, 120);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
bp = call->buffer;
xdr_decode_AFSFetchStatus(&bp, call->reply);
xdr_decode_AFSCallBack(&bp, call->reply);
if (call->reply2)
xdr_decode_AFSVolSync(&bp, call->reply2);
call->offset = 0;
call->unmarshall++;
case 4:
_debug("trailer");
if (skb->len != 0)
return -EBADMSG;
break;
}
if (!last)
return 0;
_leave(" = 0 [done]");
return 0;
}
/*
* FS.FetchData operation type
*/
static const struct afs_call_type afs_RXFSFetchData = {
.deliver = afs_deliver_fs_fetch_data,
.abort_to_error = afs_abort_to_error,
.destructor = afs_flat_call_destructor,
};
/*
* fetch data from a file
*/
int afs_fs_fetch_data(struct afs_server *server,
struct afs_vnode *vnode,
off_t offset, size_t length,
struct page *buffer,
struct afs_volsync *volsync,
const struct afs_wait_mode *wait_mode)
{
struct afs_call *call;
__be32 *bp;
_enter("");
call = afs_alloc_flat_call(&afs_RXFSFetchData, 24, 120);
if (!call)
return -ENOMEM;
call->reply = vnode;
call->reply2 = volsync;
call->reply3 = buffer;
call->service_id = FS_SERVICE;
call->port = htons(AFS_FS_PORT);
/* marshall the parameters */
bp = call->request;
bp[0] = htonl(FSFETCHDATA);
bp[1] = htonl(vnode->fid.vid);
bp[2] = htonl(vnode->fid.vnode);
bp[3] = htonl(vnode->fid.unique);
bp[4] = htonl(offset);
bp[5] = htonl(length);
return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
}
/*
* deliver reply data to an FS.GiveUpCallBacks
*/
static int afs_deliver_fs_give_up_callbacks(struct afs_call *call,
struct sk_buff *skb, bool last)
{
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG; /* shouldn't be any reply data */
return 0;
}
/*
* FS.GiveUpCallBacks operation type
*/
static const struct afs_call_type afs_RXFSGiveUpCallBacks = {
.deliver = afs_deliver_fs_give_up_callbacks,
.abort_to_error = afs_abort_to_error,
.destructor = afs_flat_call_destructor,
};
/*
* give up a set of callbacks
* - the callbacks are held in the server->cb_break ring
*/
int afs_fs_give_up_callbacks(struct afs_server *server,
const struct afs_wait_mode *wait_mode)
{
struct afs_call *call;
size_t ncallbacks;
__be32 *bp, *tp;
int loop;
ncallbacks = CIRC_CNT(server->cb_break_head, server->cb_break_tail,
ARRAY_SIZE(server->cb_break));
_enter("{%zu},", ncallbacks);
if (ncallbacks == 0)
return 0;
if (ncallbacks > AFSCBMAX)
ncallbacks = AFSCBMAX;
_debug("break %zu callbacks", ncallbacks);
call = afs_alloc_flat_call(&afs_RXFSGiveUpCallBacks,
12 + ncallbacks * 6 * 4, 0);
if (!call)
return -ENOMEM;
call->service_id = FS_SERVICE;
call->port = htons(AFS_FS_PORT);
/* marshall the parameters */
bp = call->request;
tp = bp + 2 + ncallbacks * 3;
*bp++ = htonl(FSGIVEUPCALLBACKS);
*bp++ = htonl(ncallbacks);
*tp++ = htonl(ncallbacks);
atomic_sub(ncallbacks, &server->cb_break_n);
for (loop = ncallbacks; loop > 0; loop--) {
struct afs_callback *cb =
&server->cb_break[server->cb_break_tail];
*bp++ = htonl(cb->fid.vid);
*bp++ = htonl(cb->fid.vnode);
*bp++ = htonl(cb->fid.unique);
*tp++ = htonl(cb->version);
*tp++ = htonl(cb->expiry);
*tp++ = htonl(cb->type);
smp_mb();
server->cb_break_tail =
(server->cb_break_tail + 1) &
(ARRAY_SIZE(server->cb_break) - 1);
}
ASSERT(ncallbacks > 0);
wake_up_nr(&server->cb_break_waitq, ncallbacks);
return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
}