alistair23-linux/fs/nfs/nfs4session.h
Trond Myklebust ac20d163fc NFSv4.1: Deal effectively with interrupted RPC calls.
If an RPC call is interrupted, assume that the server hasn't processed
the RPC call so that the next time we use the slot, we know that if we
get a NFS4ERR_SEQ_MISORDERED or NFS4ERR_SEQ_FALSE_RETRY, we just have
to bump the sequence number.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-15 15:39:59 -05:00

143 lines
3.9 KiB
C

/*
* fs/nfs/nfs4session.h
*
* Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
*
*/
#ifndef __LINUX_FS_NFS_NFS4SESSION_H
#define __LINUX_FS_NFS_NFS4SESSION_H
/* maximum number of slots to use */
#define NFS4_DEF_SLOT_TABLE_SIZE (16U)
#define NFS4_MAX_SLOT_TABLE (1024U)
#define NFS4_NO_SLOT ((u32)-1)
#if IS_ENABLED(CONFIG_NFS_V4)
/* Sessions slot seqid */
struct nfs4_slot {
struct nfs4_slot_table *table;
struct nfs4_slot *next;
unsigned long generation;
u32 slot_nr;
u32 seq_nr;
unsigned int interrupted : 1;
};
/* Sessions */
#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
struct nfs4_slot_table {
struct nfs4_session *session; /* Parent session */
struct nfs4_slot *slots; /* seqid per slot */
unsigned long used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
spinlock_t slot_tbl_lock;
struct rpc_wait_queue slot_tbl_waitq; /* allocators may wait here */
u32 max_slots; /* # slots in table */
u32 max_slotid; /* Max allowed slotid value */
u32 highest_used_slotid; /* sent to server on each SEQ.
* op for dynamic resizing */
u32 target_highest_slotid; /* Server max_slot target */
u32 server_highest_slotid; /* Server highest slotid */
s32 d_target_highest_slotid; /* Derivative */
s32 d2_target_highest_slotid; /* 2nd derivative */
unsigned long generation; /* Generation counter for
target_highest_slotid */
struct completion complete;
};
/*
* Session related parameters
*/
struct nfs4_session {
struct nfs4_sessionid sess_id;
u32 flags;
unsigned long session_state;
u32 hash_alg;
u32 ssv_len;
/* The fore and back channel */
struct nfs4_channel_attrs fc_attrs;
struct nfs4_slot_table fc_slot_table;
struct nfs4_channel_attrs bc_attrs;
struct nfs4_slot_table bc_slot_table;
struct nfs_client *clp;
/* Create session arguments */
unsigned int fc_target_max_rqst_sz;
unsigned int fc_target_max_resp_sz;
};
enum nfs4_session_state {
NFS4_SESSION_INITING,
NFS4_SESSION_DRAINING,
};
#if defined(CONFIG_NFS_V4_1)
extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
u32 target_highest_slotid);
extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
struct nfs4_slot *slot,
struct nfs4_sequence_res *res);
extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
extern void nfs4_destroy_session(struct nfs4_session *session);
extern int nfs4_init_session(struct nfs_server *server);
extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
extern void nfs4_session_drain_complete(struct nfs4_session *session,
struct nfs4_slot_table *tbl);
static inline bool nfs4_session_draining(struct nfs4_session *session)
{
return !!test_bit(NFS4_SESSION_DRAINING, &session->session_state);
}
bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
struct nfs4_slot *slot);
void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
/*
* Determine if sessions are in use.
*/
static inline int nfs4_has_session(const struct nfs_client *clp)
{
if (clp->cl_session)
return 1;
return 0;
}
static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
{
if (nfs4_has_session(clp))
return (clp->cl_session->flags & SESSION4_PERSIST);
return 0;
}
#else /* defined(CONFIG_NFS_V4_1) */
static inline int nfs4_init_session(struct nfs_server *server)
{
return 0;
}
/*
* Determine if sessions are in use.
*/
static inline int nfs4_has_session(const struct nfs_client *clp)
{
return 0;
}
static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
{
return 0;
}
#endif /* defined(CONFIG_NFS_V4_1) */
#endif /* IS_ENABLED(CONFIG_NFS_V4) */
#endif /* __LINUX_FS_NFS_NFS4SESSION_H */