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/*
* linux/fs/nfs/delegation.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFS file delegation management
*
*/
#include <linux/config.h>
#include <linux/completion.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"
static struct nfs_delegation *nfs_alloc_delegation(void)
{
return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
}
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)->nfs4_state);
goto out_err;
}
}
return 0;
out_err:
return status;
}
static void nfs_delegation_claim_opens(struct inode *inode)
{
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;
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
err = nfs4_open_delegation_recall(ctx->dentry, 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 nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
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 = nfs_alloc_delegation();
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->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));
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;
__nfs_revalidate_inode(NFS_SERVER(inode), inode);
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
*/
int __nfs_inode_return_delegation(struct inode *inode)
{
struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
int res = 0;
nfs_msync_inode(inode);
down_read(&clp->cl_sem);
/* Guard against new delegated open calls */
down_write(&nfsi->rwsem);
spin_lock(&clp->cl_lock);
delegation = nfsi->delegation;
if (delegation != NULL) {
list_del_init(&delegation->super_list);
nfsi->delegation = NULL;
nfsi->delegation_state = 0;
}
spin_unlock(&clp->cl_lock);
nfs_delegation_claim_opens(inode);
up_write(&nfsi->rwsem);
up_read(&clp->cl_sem);
nfs_msync_inode(inode);
if (delegation != NULL)
res = nfs_do_return_delegation(inode, delegation);
return res;
}
/*
* Return all delegations associated to a super block
*/
void nfs_return_all_delegations(struct super_block *sb)
{
struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
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;
spin_unlock(&clp->cl_lock);
nfs_inode_return_delegation(inode);
iput(inode);
goto restart;
}
spin_unlock(&clp->cl_lock);
}
/*
* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
*/
void nfs_handle_cb_pathdown(struct nfs4_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;
spin_unlock(&clp->cl_lock);
nfs_inode_return_
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