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NFSv4: Deal more correctly with duplicate delegations 

If a (broken?) server hands out two different delegations for the same
file, then we should return one of them.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2008-01-25 16:38:18 -05:00
parent 6f23e3872c
commit 57bfa89171
1 changed files with 51 additions and 38 deletions
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87
fs/nfs/delegation.c
View File

@ -125,6 +125,32 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, st
put_rpccred(oldcred);
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
int res = 0;
res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
nfs_free_delegation(delegation);
return res;
}
static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
{
struct nfs_delegation *delegation = rcu_dereference(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_rcu(&delegation->super_list);
nfsi->delegation_state = 0;
rcu_assign_pointer(nfsi->delegation, NULL);
return delegation;
nomatch:
return NULL;
}
/*
* Set up a delegation on an inode
*/
@ -133,6 +159,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_delegation *delegation;
struct nfs_delegation *freeme = NULL;
int status = 0;
delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
@ -147,42 +174,45 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
delegation->inode = inode;
spin_lock(&clp->cl_lock);
if (rcu_dereference(nfsi->delegation) == NULL) {
if (rcu_dereference(nfsi->delegation) != NULL) {
if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
sizeof(delegation->stateid)) == 0 &&
delegation->type == nfsi->delegation->type) {
goto out;
}
/*
* Deal with broken servers that hand out two
* delegations for the same file.
*/
dfprintk(FILE, "%s: server %s handed out "
"a duplicate delegation!\n",
__FUNCTION__, clp->cl_hostname);
if (delegation->type <= nfsi->delegation->type) {
freeme = delegation;
delegation = NULL;
goto out;
}
freeme = nfs_detach_delegation_locked(nfsi, NULL);
}
list_add_rcu(&delegation->super_list, &clp->cl_delegations);
nfsi->delegation_state = delegation->type;
rcu_assign_pointer(nfsi->delegation, delegation);
delegation = NULL;
} else {
if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
sizeof(delegation->stateid)) != 0 ||
delegation->type != nfsi->delegation->type) {
printk(KERN_WARNING "%s: server %s handed out "
"a duplicate delegation!\n",
__FUNCTION__, clp->cl_hostname);
status = -EIO;
}
}
/* Ensure we revalidate the attributes and page cache! */
spin_lock(&inode->i_lock);
nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
spin_unlock(&inode->i_lock);
out:
spin_unlock(&clp->cl_lock);
if (delegation != NULL)
nfs_free_delegation(delegation);
if (freeme != NULL)
nfs_do_return_delegation(inode, freeme, 0);
return status;
}
static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
int res = 0;
res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
nfs_free_delegation(delegation);
return res;
}
/* Sync all data to disk upon delegation return */
static void nfs_msync_inode(struct inode *inode)
{
@ -211,23 +241,6 @@ static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegat
return nfs_do_return_delegation(inode, delegation, 1);
}
static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
{
struct nfs_delegation *delegation = rcu_dereference(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_rcu(&delegation->super_list);
nfsi->delegation_state = 0;
rcu_assign_pointer(nfsi->delegation, NULL);
return delegation;
nomatch:
return NULL;
}
/*
* This function returns the delegation without reclaiming opens
* or protecting against delegation reclaims.