tmp_suning_uos_patched/fs/nfs/delegation.c
Trond Myklebust 9016302784 NFSv4: Support recalling delegations by stateid
There appear to be some rogue servers out there that issue multiple
delegations with different stateids for the same file. Ensure that when we
return delegations, we do so on a per-stateid basis rather than a per-file
basis.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:40 -04:00

458 lines
12 KiB
C

/*
* linux/fs/nfs/delegation.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFS file delegation management
*
*/
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>
#include "nfs4_fs.h"
#include "delegation.h"
#include "internal.h"
static void nfs_free_delegation(struct nfs_delegation *delegation)
{
if (delegation->cred)
put_rpccred(delegation->cred);
kfree(delegation);
}
static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
{
struct inode *inode = state->inode;
struct file_lock *fl;
int status;
for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
continue;
if ((struct nfs_open_context *)fl->fl_file->private_data != ctx)
continue;
status = nfs4_lock_delegation_recall(state, fl);
if (status >= 0)
continue;
switch (status) {
default:
printk(KERN_ERR "%s: unhandled error %d.\n",
__FUNCTION__, status);
case -NFS4ERR_EXPIRED:
/* kill_proc(fl->fl_pid, SIGLOST, 1); */
case -NFS4ERR_STALE_CLIENTID:
nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
goto out_err;
}
}
return 0;
out_err:
return status;
}
static void nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *ctx;
struct nfs4_state *state;
int err;
again:
spin_lock(&inode->i_lock);
list_for_each_entry(ctx, &nfsi->open_files, list) {
state = ctx->state;
if (state == NULL)
continue;
if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
continue;
if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
continue;
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
err = nfs4_open_delegation_recall(ctx, state);
if (err >= 0)
err = nfs_delegation_claim_locks(ctx, state);
put_nfs_open_context(ctx);
if (err != 0)
return;
goto again;
}
spin_unlock(&inode->i_lock);
}
/*
* Set up a delegation on an inode
*/
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
struct nfs_delegation *delegation = NFS_I(inode)->delegation;
if (delegation == NULL)
return;
memcpy(delegation->stateid.data, res->delegation.data,
sizeof(delegation->stateid.data));
delegation->type = res->delegation_type;
delegation->maxsize = res->maxsize;
put_rpccred(cred);
delegation->cred = get_rpccred(cred);
delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
NFS_I(inode)->delegation_state = delegation->type;
smp_wmb();
}
/*
* Set up a delegation on an inode
*/
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int status = 0;
/* Ensure we first revalidate the attributes and page cache! */
if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
__nfs_revalidate_inode(NFS_SERVER(inode), inode);
delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
if (delegation == NULL)
return -ENOMEM;
memcpy(delegation->stateid.data, res->delegation.data,
sizeof(delegation->stateid.data));
delegation->type = res->delegation_type;
delegation->maxsize = res->maxsize;
delegation->change_attr = nfsi->change_attr;
delegation->cred = get_rpccred(cred);
delegation->inode = inode;
spin_lock(&clp->cl_lock);
if (nfsi->delegation == NULL) {
list_add(&delegation->super_list, &clp->cl_delegations);
nfsi->delegation = delegation;
nfsi->delegation_state = delegation->type;
delegation = NULL;
} else {
if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
sizeof(delegation->stateid)) != 0 ||
delegation->type != nfsi->delegation->type) {
printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
__FUNCTION__, NIPQUAD(clp->cl_addr.sin_addr));
status = -EIO;
}
}
spin_unlock(&clp->cl_lock);
kfree(delegation);
return status;
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
{
int res = 0;
res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
nfs_free_delegation(delegation);
return res;
}
/* Sync all data to disk upon delegation return */
static void nfs_msync_inode(struct inode *inode)
{
filemap_fdatawrite(inode->i_mapping);
nfs_wb_all(inode);
filemap_fdatawait(inode->i_mapping);
}
/*
* Basic procedure for returning a delegation to the server
*/
static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
nfs_msync_inode(inode);
down_read(&clp->cl_sem);
/* Guard against new delegated open calls */
down_write(&nfsi->rwsem);
nfs_delegation_claim_opens(inode, &delegation->stateid);
up_write(&nfsi->rwsem);
up_read(&clp->cl_sem);
nfs_msync_inode(inode);
return nfs_do_return_delegation(inode, delegation);
}
static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
{
struct nfs_delegation *delegation = nfsi->delegation;
if (delegation == NULL)
goto nomatch;
if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
sizeof(delegation->stateid.data)) != 0)
goto nomatch;
list_del_init(&delegation->super_list);
nfsi->delegation = NULL;
nfsi->delegation_state = 0;
return delegation;
nomatch:
return NULL;
}
int nfs_inode_return_delegation(struct inode *inode)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int err = 0;
if (nfsi->delegation_state != 0) {
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(nfsi, NULL);
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
err = __nfs_inode_return_delegation(inode, delegation);
}
return err;
}
/*
* Return all delegations associated to a super block
*/
void nfs_return_all_delegations(struct super_block *sb)
{
struct nfs_client *clp = NFS_SB(sb)->nfs_client;
struct nfs_delegation *delegation;
struct inode *inode;
if (clp == NULL)
return;
restart:
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
if (delegation->inode->i_sb != sb)
continue;
inode = igrab(delegation->inode);
if (inode == NULL)
continue;
nfs_detach_delegation_locked(NFS_I(inode), NULL);
spin_unlock(&clp->cl_lock);
__nfs_inode_return_delegation(inode, delegation);
iput(inode);
goto restart;
}
spin_unlock(&clp->cl_lock);
}
static int nfs_do_expire_all_delegations(void *ptr)
{
struct nfs_client *clp = ptr;
struct nfs_delegation *delegation;
struct inode *inode;
allow_signal(SIGKILL);
restart:
spin_lock(&clp->cl_lock);
if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
goto out;
if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
goto out;
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
inode = igrab(delegation->inode);
if (inode == NULL)
continue;
nfs_detach_delegation_locked(NFS_I(inode), NULL);
spin_unlock(&clp->cl_lock);
__nfs_inode_return_delegation(inode, delegation);
iput(inode);
goto restart;
}
out:
spin_unlock(&clp->cl_lock);
nfs_put_client(clp);
module_put_and_exit(0);
}
void nfs_expire_all_delegations(struct nfs_client *clp)
{
struct task_struct *task;
__module_get(THIS_MODULE);
atomic_inc(&clp->cl_count);
task = kthread_run(nfs_do_expire_all_delegations, clp,
"%u.%u.%u.%u-delegreturn",
NIPQUAD(clp->cl_addr.sin_addr));
if (!IS_ERR(task))
return;
nfs_put_client(clp);
module_put(THIS_MODULE);
}
/*
* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
*/
void nfs_handle_cb_pathdown(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
struct inode *inode;
if (clp == NULL)
return;
restart:
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
inode = igrab(delegation->inode);
if (inode == NULL)
continue;
nfs_detach_delegation_locked(NFS_I(inode), NULL);
spin_unlock(&clp->cl_lock);
__nfs_inode_return_delegation(inode, delegation);
iput(inode);
goto restart;
}
spin_unlock(&clp->cl_lock);
}
struct recall_threadargs {
struct inode *inode;
struct nfs_client *clp;
const nfs4_stateid *stateid;
struct completion started;
int result;
};
static int recall_thread(void *data)
{
struct recall_threadargs *args = (struct recall_threadargs *)data;
struct inode *inode = igrab(args->inode);
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
daemonize("nfsv4-delegreturn");
nfs_msync_inode(inode);
down_read(&clp->cl_sem);
down_write(&nfsi->rwsem);
spin_lock(&clp->cl_lock);
delegation = nfs_detach_delegation_locked(nfsi, args->stateid);
if (delegation != NULL)
args->result = 0;
else
args->result = -ENOENT;
spin_unlock(&clp->cl_lock);
complete(&args->started);
nfs_delegation_claim_opens(inode, args->stateid);
up_write(&nfsi->rwsem);
up_read(&clp->cl_sem);
nfs_msync_inode(inode);
if (delegation != NULL)
nfs_do_return_delegation(inode, delegation);
iput(inode);
module_put_and_exit(0);
}
/*
* Asynchronous delegation recall!
*/
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
{
struct recall_threadargs data = {
.inode = inode,
.stateid = stateid,
};
int status;
init_completion(&data.started);
__module_get(THIS_MODULE);
status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
if (status < 0)
goto out_module_put;
wait_for_completion(&data.started);
return data.result;
out_module_put:
module_put(THIS_MODULE);
return status;
}
/*
* Retrieve the inode associated with a delegation
*/
struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
{
struct nfs_delegation *delegation;
struct inode *res = NULL;
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
res = igrab(delegation->inode);
break;
}
}
spin_unlock(&clp->cl_lock);
return res;
}
/*
* Mark all delegations as needing to be reclaimed
*/
void nfs_delegation_mark_reclaim(struct nfs_client *clp)
{
struct nfs_delegation *delegation;
spin_lock(&clp->cl_lock);
list_for_each_entry(delegation, &clp->cl_delegations, super_list)
delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
spin_unlock(&clp->cl_lock);
}
/*
* Reap all unclaimed delegations after reboot recovery is done
*/
void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
{
struct nfs_delegation *delegation, *n;
LIST_HEAD(head);
spin_lock(&clp->cl_lock);
list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
continue;
list_move(&delegation->super_list, &head);
NFS_I(delegation->inode)->delegation = NULL;
NFS_I(delegation->inode)->delegation_state = 0;
}
spin_unlock(&clp->cl_lock);
while(!list_empty(&head)) {
delegation = list_entry(head.next, struct nfs_delegation, super_list);
list_del(&delegation->super_list);
nfs_free_delegation(delegation);
}
}
int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
{
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int res = 0;
if (nfsi->delegation_state == 0)
return 0;
spin_lock(&clp->cl_lock);
delegation = nfsi->delegation;
if (delegation != NULL) {
memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
res = 1;
}
spin_unlock(&clp->cl_lock);
return res;
}