/*
* pNFS client data structures.
*
* Copyright (c) 2002
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <dhildebz@umich.edu>
*
* Permission is granted to use, copy, create derivative works, and
* redistribute this software and such derivative works for any purpose,
* so long as the name of the University of Michigan is not used in
* any advertising or publicity pertaining to the use or distribution
* of this software without specific, written prior authorization. If
* the above copyright notice or any other identification of the
* University of Michigan is included in any copy of any portion of
* this software, then the disclaimer below must also be included.
*
* This software is provided as is, without representation or warranty
* of any kind either express or implied, including without limitation
* the implied warranties of merchantability, fitness for a particular
* purpose, or noninfringement. The Regents of the University of
* Michigan shall not be liable for any damages, including special,
* indirect, incidental, or consequential damages, with respect to any
* claim arising out of or in connection with the use of the software,
* even if it has been or is hereafter advised of the possibility of
* such damages.
*/
#ifndef FS_NFS_PNFS_H
#define FS_NFS_PNFS_H
enum {
NFS_LSEG_VALID = 0, /* cleared when lseg is recalled/returned */
};
struct pnfs_layout_segment {
struct list_head pls_list;
struct pnfs_layout_range pls_range;
atomic_t pls_refcount;
unsigned long pls_flags;
struct pnfs_layout_hdr *pls_layout;
};
#ifdef CONFIG_NFS_V4_1
#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
enum {
NFS_LAYOUT_RO_FAILED = 0, /* get ro layout failed stop trying */
NFS_LAYOUT_RW_FAILED, /* get rw layout failed stop trying */
NFS_LAYOUT_DESTROYED, /* no new use of layout allowed */
};
/* Per-layout driver specific registration structure */
struct pnfs_layoutdriver_type {
struct list_head pnfs_tblid;
const u32 id;
const char *name;
struct module *owner;
int (*set_layoutdriver) (struct nfs_server *);
int (*clear_layoutdriver) (struct nfs_server *);
struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
void (*free_lseg) (struct pnfs_layout_segment *lseg);
};
struct pnfs_layout_hdr {
unsigned long plh_refcount;
struct list_head plh_layouts; /* other client layouts */
struct list_head plh_segs; /* layout segments list */
nfs4_stateid plh_stateid;
unsigned long plh_flags;
struct inode *plh_inode;
};
struct pnfs_device {
struct nfs4_deviceid dev_id;
unsigned int layout_type;
unsigned int mincount;
struct page **pages;
void *area;
unsigned int pgbase;
unsigned int pglen;
};
/*
* Device ID RCU cache. A device ID is unique per client ID and layout type.
*/
#define NFS4_DEVICE_ID_HASH_BITS 5
#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
static inline u32
nfs4_deviceid_hash(struct nfs4_deviceid *id)
{
unsigned char *cptr = (unsigned char *)id->data;
unsigned int nbytes = NFS4_DEVICEID4_SIZE;
u32 x = 0;
while (nbytes--) {
x *= 37;
x += *cptr++;
}
return x & NFS4_DEVICE_ID_HASH_MASK;
}
struct pnfs_deviceid_node {
struct hlist_node de_node;
struct nfs4_deviceid de_id;
atomic_t de_ref;
};
struct pnfs_deviceid_cache {
spinlock_t dc_lock;
atomic_t dc_ref;
void (*dc_free_callback)(struct pnfs_deviceid_node *);
struct hlist_head dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
};
extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
void (*free_callback)(struct pnfs_deviceid_node *));
extern void pnfs_put_deviceid_cache(struct nfs_client *);
extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
struct pnfs_deviceid_cache *,
struct nfs4_deviceid *);
extern struct pnfs_deviceid_node *pnfs_add_deviceid(
struct pnfs_deviceid_cache *,
struct pnfs_deviceid_node *);
extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
struct pnfs_deviceid_node *devid);
extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
/* nfs4proc.c */
extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
struct pnfs_device *dev);
extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
/* pnfs.c */
struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
enum pnfs_iomode access_type);
void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
void unset_pnfs_layoutdriver(struct nfs_server *);
int pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
void put_layout_hdr(struct inode *inode);
int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state);
static inline int lo_fail_bit(u32 iomode)
{
return iomode == IOMODE_RW ?
NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
}
/* Return true if a layout driver is being used for this mountpoint */
static inline int pnfs_enabled_sb(struct nfs_server *nfss)
{
return nfss->pnfs_curr_ld != NULL;
}
#else /* CONFIG_NFS_V4_1 */
static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
{
}
static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
{
}
static inline struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
enum pnfs_iomode access_type)
{
return NULL;
}
static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
{
}
static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
{
}
#endif /* CONFIG_NFS_V4_1 */
#endif /* FS_NFS_PNFS_H */
