kernel-ark/fs/nfs/callback_proc.c

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/*
* linux/fs/nfs/callback_proc.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFSv4 callback procedures
*/
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "internal.h"
#ifdef NFS_DEBUG
#define NFSDBG_FACILITY NFSDBG_CALLBACK
#endif
__be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *res)
{
struct nfs_client *clp;
struct nfs_delegation *delegation;
struct nfs_inode *nfsi;
struct inode *inode;
res->bitmap[0] = res->bitmap[1] = 0;
res->status = htonl(NFS4ERR_BADHANDLE);
clp = nfs_find_client(args->addr, 4);
if (clp == NULL)
goto out;
dprintk("NFS: GETATTR callback request from %s\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
inode = nfs_delegation_find_inode(clp, &args->fh);
if (inode == NULL)
goto out_putclient;
nfsi = NFS_I(inode);
down_read(&nfsi->rwsem);
delegation = nfsi->delegation;
if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
goto out_iput;
res->size = i_size_read(inode);
res->change_attr = delegation->change_attr;
if (nfsi->npages != 0)
res->change_attr++;
res->ctime = inode->i_ctime;
res->mtime = inode->i_mtime;
res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
args->bitmap[0];
res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
args->bitmap[1];
res->status = 0;
out_iput:
up_read(&nfsi->rwsem);
iput(inode);
out_putclient:
nfs_put_client(clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
return res->status;
}
__be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
{
struct nfs_client *clp;
struct inode *inode;
__be32 res;
res = htonl(NFS4ERR_BADHANDLE);
clp = nfs_find_client(args->addr, 4);
if (clp == NULL)
goto out;
dprintk("NFS: RECALL callback request from %s\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
do {
struct nfs_client *prev = clp;
inode = nfs_delegation_find_inode(clp, &args->fh);
if (inode != NULL) {
/* Set up a helper thread to actually return the delegation */
switch(nfs_async_inode_return_delegation(inode, &args->stateid)) {
case 0:
res = 0;
break;
case -ENOENT:
if (res != 0)
res = htonl(NFS4ERR_BAD_STATEID);
break;
default:
res = htonl(NFS4ERR_RESOURCE);
}
iput(inode);
}
clp = nfs_find_client_next(prev);
nfs_put_client(prev);
} while (clp != NULL);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
return res;
}
#if defined(CONFIG_NFS_V4_1)
/*
* Validate the sequenceID sent by the server.
* Return success if the sequenceID is one more than what we last saw on
* this slot, accounting for wraparound. Increments the slot's sequence.
*
* We don't yet implement a duplicate request cache, so at this time
* we will log replays, and process them as if we had not seen them before,
* but we don't bump the sequence in the slot. Not too worried about it,
* since we only currently implement idempotent callbacks anyway.
*
* We have a single slot backchannel at this time, so we don't bother
* checking the used_slots bit array on the table. The lower layer guarantees
* a single outstanding callback request at a time.
*/
static int
validate_seqid(struct nfs4_slot_table *tbl, u32 slotid, u32 seqid)
{
struct nfs4_slot *slot;
dprintk("%s enter. slotid %d seqid %d\n",
__func__, slotid, seqid);
if (slotid > NFS41_BC_MAX_CALLBACKS)
return htonl(NFS4ERR_BADSLOT);
slot = tbl->slots + slotid;
dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
/* Normal */
if (likely(seqid == slot->seq_nr + 1)) {
slot->seq_nr++;
return htonl(NFS4_OK);
}
/* Replay */
if (seqid == slot->seq_nr) {
dprintk("%s seqid %d is a replay - no DRC available\n",
__func__, seqid);
return htonl(NFS4_OK);
}
/* Wraparound */
if (seqid == 1 && (slot->seq_nr + 1) == 0) {
slot->seq_nr = 1;
return htonl(NFS4_OK);
}
/* Misordered request */
return htonl(NFS4ERR_SEQ_MISORDERED);
}
/*
* Returns a pointer to a held 'struct nfs_client' that matches the server's
* address, major version number, and session ID. It is the caller's
* responsibility to release the returned reference.
*
* Returns NULL if there are no connections with sessions, or if no session
* matches the one of interest.
*/
static struct nfs_client *find_client_with_session(
const struct sockaddr *addr, u32 nfsversion,
struct nfs4_sessionid *sessionid)
{
struct nfs_client *clp;
clp = nfs_find_client(addr, 4);
if (clp == NULL)
return NULL;
do {
struct nfs_client *prev = clp;
if (clp->cl_session != NULL) {
if (memcmp(clp->cl_session->sess_id.data,
sessionid->data,
NFS4_MAX_SESSIONID_LEN) == 0) {
/* Returns a held reference to clp */
return clp;
}
}
clp = nfs_find_client_next(prev);
nfs_put_client(prev);
} while (clp != NULL);
return NULL;
}
/* FIXME: referring calls should be processed */
unsigned nfs4_callback_sequence(struct cb_sequenceargs *args,
struct cb_sequenceres *res)
{
struct nfs_client *clp;
int i, status;
for (i = 0; i < args->csa_nrclists; i++)
kfree(args->csa_rclists[i].rcl_refcalls);
kfree(args->csa_rclists);
status = htonl(NFS4ERR_BADSESSION);
clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid);
if (clp == NULL)
goto out;
status = validate_seqid(&clp->cl_session->bc_slot_table,
args->csa_slotid, args->csa_sequenceid);
if (status)
goto out_putclient;
memcpy(&res->csr_sessionid, &args->csa_sessionid,
sizeof(res->csr_sessionid));
res->csr_sequenceid = args->csa_sequenceid;
res->csr_slotid = args->csa_slotid;
res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
out_putclient:
nfs_put_client(clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
res->csr_status = status;
return res->csr_status;
}
#endif /* CONFIG_NFS_V4_1 */