android_kernel_samsung_msm8976/fs/nfs/delegation.h
Trond Myklebust d25be546a8 NFSv4.1: Don't lose locks when a server reboots during delegation return
If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).

Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.

Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-02-11 15:33:12 -05:00

70 lines
2.4 KiB
C

/*
* 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;
struct rpc_cred *cred;
struct inode *inode;
nfs4_stateid stateid;
fmode_t type;
loff_t maxsize;
__u64 change_attr;
unsigned long flags;
spinlock_t lock;
struct rcu_head rcu;
};
enum {
NFS_DELEGATION_NEED_RECLAIM = 0,
NFS_DELEGATION_RETURN,
NFS_DELEGATION_REFERENCED,
NFS_DELEGATION_RETURNING,
};
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
int nfs4_inode_return_delegation(struct inode *inode);
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
void nfs_inode_return_delegation_noreclaim(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_all_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);
void nfs_delegation_mark_reclaim(struct nfs_client *clp);
void nfs_delegation_reap_unclaimed(struct nfs_client *clp);
/* NFSv4 delegation-related procedures */
int nfs4_proc_delegreturn(struct inode *inode, struct rpc_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 nfs4_state *state, struct file_lock *fl);
bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, fmode_t flags);
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
int nfs4_have_delegation(struct inode *inode, fmode_t flags);
#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