linux/fs/nfs/pnfs.h

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/*
* 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
#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 */
};
/* 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 (*initialize_mountpoint) (struct nfs_server *);
int (*uninitialize_mountpoint) (struct nfs_server *);
};
struct pnfs_layout_hdr {
unsigned long refcount;
unsigned long state;
struct inode *inode;
};
extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
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 *);
void pnfs_destroy_layout(struct nfs_inode *);
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_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 */