NFS refactor nfs_find_client and reference client across callback processing

Fixes a bug where the nfs_client could be freed during callback processing.
Refactor nfs_find_client to use minorversion specific means to locate the
correct nfs_client structure.

In the NFS layer, V4.0 clients are found using the callback_ident field in the
CB_COMPOUND header.  V4.1 clients are found using the sessionID in the
CB_SEQUENCE operation which is also compared against the sessionID associated
with the back channel thread after a successful CREATE_SESSION.

Each of these methods finds the one an only nfs_client associated
with the incoming callback request - so nfs_find_client_next is not needed.

In the RPC layer, the pg_authenticate call needs to find the nfs_client. For
the v4.0 callback service, the callback identifier has not been decoded so a
search by address, version, and minorversion is used.  The sessionid for the
sessions based callback service has (usually) not been set for the
pg_authenticate on a CB_NULL call which can be sent prior to the return
of a CREATE_SESSION call, so the sessionid associated with the back channel
thread is not used to find the client in pg_authenticate for CB_NULL calls.

Pass the referenced nfs_client to each CB_COMPOUND operation being proceesed
via the new cb_process_state structure. The reference is held across
cb_compound processing.

Use the new cb_process_state struct to move the NFS4ERR_RETRY_UNCACHED_REP
processing from process_op into nfs4_callback_sequence where it belongs.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Andy Adamson 2011-01-06 02:04:32 +00:00 committed by Trond Myklebust
parent 2c2618c6f2
commit c36fca52f5
7 changed files with 259 additions and 189 deletions

View file

@ -16,26 +16,28 @@
#ifdef NFS_DEBUG
#define NFSDBG_FACILITY NFSDBG_CALLBACK
#endif
__be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *res)
__be32 nfs4_callback_getattr(struct cb_getattrargs *args,
struct cb_getattrres *res,
struct cb_process_state *cps)
{
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)
res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
goto out;
dprintk("NFS: GETATTR callback request from %s\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
res->bitmap[0] = res->bitmap[1] = 0;
res->status = htonl(NFS4ERR_BADHANDLE);
inode = nfs_delegation_find_inode(clp, &args->fh);
dprintk("NFS: GETATTR callback request from %s\n",
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
inode = nfs_delegation_find_inode(cps->clp, &args->fh);
if (inode == NULL)
goto out_putclient;
goto out;
nfsi = NFS_I(inode);
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
@ -55,49 +57,41 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *
out_iput:
rcu_read_unlock();
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)
__be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
struct cb_process_state *cps)
{
struct nfs_client *clp;
struct inode *inode;
__be32 res;
res = htonl(NFS4ERR_BADHANDLE);
clp = nfs_find_client(args->addr, 4);
if (clp == NULL)
res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
goto out;
dprintk("NFS: RECALL callback request from %s\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
rpc_peeraddr2str(cps->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);
res = htonl(NFS4ERR_BADHANDLE);
inode = nfs_delegation_find_inode(cps->clp, &args->fh);
if (inode == NULL)
goto out;
/* 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);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
return res;
@ -184,42 +178,6 @@ validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
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;
}
/*
* For each referring call triple, check the session's slot table for
* a match. If the slot is in use and the sequence numbers match, the
@ -276,20 +234,28 @@ out:
}
__be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
struct cb_sequenceres *res)
struct cb_sequenceres *res,
struct cb_process_state *cps)
{
struct nfs_client *clp;
int i;
__be32 status;
cps->clp = NULL;
status = htonl(NFS4ERR_BADSESSION);
clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid);
/* Incoming session must match the callback session */
if (memcmp(&args->csa_sessionid, cps->svc_sid, NFS4_MAX_SESSIONID_LEN))
goto out;
clp = nfs4_find_client_sessionid(args->csa_addr,
&args->csa_sessionid, 1);
if (clp == NULL)
goto out;
status = validate_seqid(&clp->cl_session->bc_slot_table, args);
if (status)
goto out_putclient;
goto out;
/*
* Check for pending referring calls. If a match is found, a
@ -298,7 +264,7 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
*/
if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
status = htonl(NFS4ERR_DELAY);
goto out_putclient;
goto out;
}
memcpy(&res->csr_sessionid, &args->csa_sessionid,
@ -307,36 +273,36 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
res->csr_slotid = args->csa_slotid;
res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
cps->clp = clp; /* put in nfs4_callback_compound */
out_putclient:
nfs_put_client(clp);
out:
for (i = 0; i < args->csa_nrclists; i++)
kfree(args->csa_rclists[i].rcl_refcalls);
kfree(args->csa_rclists);
if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP))
res->csr_status = 0;
else
if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
cps->drc_status = status;
status = 0;
} else
res->csr_status = status;
dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
ntohl(status), ntohl(res->csr_status));
return status;
}
__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
struct cb_process_state *cps)
{
struct nfs_client *clp;
__be32 status;
fmode_t flags = 0;
status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
clp = nfs_find_client(args->craa_addr, 4);
if (clp == NULL)
if (!cps->clp) /* set in cb_sequence */
goto out;
dprintk("NFS: RECALL_ANY callback request from %s\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
&args->craa_type_mask))
@ -346,7 +312,7 @@ __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
flags |= FMODE_WRITE;
if (flags)
nfs_expire_all_delegation_types(clp, flags);
nfs_expire_all_delegation_types(cps->clp, flags);
status = htonl(NFS4_OK);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
@ -354,36 +320,33 @@ out:
}
/* Reduce the fore channel's max_slots to the target value */
__be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy)
__be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
struct cb_process_state *cps)
{
struct nfs_client *clp;
struct nfs4_slot_table *fc_tbl;
__be32 status;
status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
clp = nfs_find_client(args->crsa_addr, 4);
if (clp == NULL)
if (!cps->clp) /* set in cb_sequence */
goto out;
dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
args->crsa_target_max_slots);
fc_tbl = &clp->cl_session->fc_slot_table;
fc_tbl = &cps->clp->cl_session->fc_slot_table;
status = htonl(NFS4ERR_BAD_HIGH_SLOT);
if (args->crsa_target_max_slots > fc_tbl->max_slots ||
args->crsa_target_max_slots < 1)
goto out_putclient;
goto out;
status = htonl(NFS4_OK);
if (args->crsa_target_max_slots == fc_tbl->max_slots)
goto out_putclient;
goto out;
fc_tbl->target_max_slots = args->crsa_target_max_slots;
nfs41_handle_recall_slot(clp);
out_putclient:
nfs_put_client(clp); /* balance nfs_find_client */
nfs41_handle_recall_slot(cps->clp);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;