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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-01-25 22:38:18 +0100 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-01-30 08:06:12 +0100 |
commit | 57bfa89171e50cddf51a4f62c90e47c6259857b4 (patch) | |
tree | 2c3f6d45a61b4f888544d492d78fedd797001bc8 /fs/nfs/delegation.c | |
parent | NFS: Fix a potential race between umount and nfs_access_cache_shrinker() (diff) | |
download | linux-57bfa89171e50cddf51a4f62c90e47c6259857b4.tar.xz linux-57bfa89171e50cddf51a4f62c90e47c6259857b4.zip |
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>
Diffstat (limited to 'fs/nfs/delegation.c')
-rw-r--r-- | fs/nfs/delegation.c | 89 |
1 files changed, 51 insertions, 38 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 2dead8d1dd55..b9eadd18ba70 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -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) { - list_add_rcu(&delegation->super_list, &clp->cl_delegations); - nfsi->delegation_state = delegation->type; - rcu_assign_pointer(nfsi->delegation, delegation); - delegation = NULL; - } else { + if (rcu_dereference(nfsi->delegation) != NULL) { 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; + 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; /* 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. |