linux/fs/nfs/delegation.h
Trond Myklebust 8c75593c6e NFSv4: Ensure the delegation is pinned in nfs_do_return_delegation()
The call to nfs_do_return_delegation() needs to be taken without
any RCU locks. Add a refcount to make sure the delegation remains
pinned in memory until we're done.

Fixes: ee05f45677 ("NFSv4: Fix races between open and delegreturn")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-02-13 16:18:50 -05:00

91 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/fs/nfs/delegation.h
*
* Copyright (c) Trond Myklebust
*
* Definitions pertaining to NFS delegated files
*/
#ifndef FS_NFS_DELEGATION_H
#define FS_NFS_DELEGATION_H
#if IS_ENABLED(CONFIG_NFS_V4)
/*
* NFSv4 delegation
*/
struct nfs_delegation {
struct list_head super_list;
const struct cred *cred;
struct inode *inode;
nfs4_stateid stateid;
fmode_t type;
unsigned long pagemod_limit;
__u64 change_attr;
unsigned long flags;
refcount_t refcount;
spinlock_t lock;
struct rcu_head rcu;
};
enum {
NFS_DELEGATION_NEED_RECLAIM = 0,
NFS_DELEGATION_RETURN,
NFS_DELEGATION_RETURN_IF_CLOSED,
NFS_DELEGATION_REFERENCED,
NFS_DELEGATION_RETURNING,
NFS_DELEGATION_REVOKED,
NFS_DELEGATION_TEST_EXPIRED,
NFS_DELEGATION_INODE_FREEING,
};
int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
int nfs4_inode_return_delegation(struct inode *inode);
void nfs4_inode_return_delegation_on_close(struct inode *inode);
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
void nfs_inode_evict_delegation(struct inode *inode);
struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle);
void nfs_server_return_all_delegations(struct nfs_server *);
void nfs_expire_all_delegations(struct nfs_client *clp);
void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags);
void nfs_expire_unreferenced_delegations(struct nfs_client *clp);
int nfs_client_return_marked_delegations(struct nfs_client *clp);
int nfs_delegations_present(struct nfs_client *clp);
void nfs_remove_bad_delegation(struct inode *inode, const nfs4_stateid *stateid);
void nfs_delegation_mark_returned(struct inode *inode, const nfs4_stateid *stateid);
void nfs_delegation_mark_reclaim(struct nfs_client *clp);
void nfs_delegation_reap_unclaimed(struct nfs_client *clp);
void nfs_mark_test_expired_all_delegations(struct nfs_client *clp);
void nfs_test_expired_all_delegations(struct nfs_client *clp);
void nfs_reap_expired_delegations(struct nfs_client *clp);
/* NFSv4 delegation-related procedures */
int nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred, const nfs4_stateid *stateid, int issync);
int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid);
int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid);
bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, const struct cred **cred);
bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode);
struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode);
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
int nfs4_have_delegation(struct inode *inode, fmode_t flags);
int nfs4_check_delegation(struct inode *inode, fmode_t flags);
bool nfs4_delegation_flush_on_close(const struct inode *inode);
void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
const nfs4_stateid *stateid);
int nfs4_inode_make_writeable(struct inode *inode);
#endif
static inline int nfs_have_delegated_attributes(struct inode *inode)
{
return NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) &&
!(NFS_I(inode)->cache_validity & NFS_INO_REVAL_FORCED);
}
#endif