Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
		
			
				
	
	
		
			214 lines
		
	
	
	
		
			6.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			214 lines
		
	
	
	
		
			6.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/* NFS filesystem cache interface definitions
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 *
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 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
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 * Written by David Howells (dhowells@redhat.com)
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public Licence
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 * as published by the Free Software Foundation; either version
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 * 2 of the Licence, or (at your option) any later version.
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 */
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#ifndef _NFS_FSCACHE_H
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#define _NFS_FSCACHE_H
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#include <linux/nfs_fs.h>
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#include <linux/nfs_mount.h>
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#include <linux/nfs4_mount.h>
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#include <linux/fscache.h>
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#ifdef CONFIG_NFS_FSCACHE
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/*
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 * set of NFS FS-Cache objects that form a superblock key
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 */
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struct nfs_fscache_key {
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	struct rb_node		node;
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	struct nfs_client	*nfs_client;	/* the server */
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	/* the elements of the unique key - as used by nfs_compare_super() and
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	 * nfs_compare_mount_options() to distinguish superblocks */
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	struct {
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		struct {
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			unsigned long	s_flags;	/* various flags
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							 * (& NFS_MS_MASK) */
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		} super;
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		struct {
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			struct nfs_fsid fsid;
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			int		flags;
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			unsigned int	rsize;		/* read size */
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			unsigned int	wsize;		/* write size */
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			unsigned int	acregmin;	/* attr cache timeouts */
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			unsigned int	acregmax;
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			unsigned int	acdirmin;
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			unsigned int	acdirmax;
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		} nfs_server;
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		struct {
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			rpc_authflavor_t au_flavor;
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		} rpc_auth;
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		/* uniquifier - can be used if nfs_server.flags includes
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		 * NFS_MOUNT_UNSHARED  */
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		u8 uniq_len;
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		char uniquifier[0];
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	} key;
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};
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/*
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 * fscache-index.c
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 */
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extern struct fscache_netfs nfs_fscache_netfs;
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extern const struct fscache_cookie_def nfs_fscache_server_index_def;
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extern const struct fscache_cookie_def nfs_fscache_super_index_def;
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extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
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extern int nfs_fscache_register(void);
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extern void nfs_fscache_unregister(void);
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/*
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 * fscache.c
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 */
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extern void nfs_fscache_get_client_cookie(struct nfs_client *);
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extern void nfs_fscache_release_client_cookie(struct nfs_client *);
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extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
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extern void nfs_fscache_release_super_cookie(struct super_block *);
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extern void nfs_fscache_init_inode_cookie(struct inode *);
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extern void nfs_fscache_release_inode_cookie(struct inode *);
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extern void nfs_fscache_zap_inode_cookie(struct inode *);
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extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *);
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extern void nfs_fscache_reset_inode_cookie(struct inode *);
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extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
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extern int nfs_fscache_release_page(struct page *, gfp_t);
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extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
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				       struct inode *, struct page *);
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extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
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					struct inode *, struct address_space *,
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					struct list_head *, unsigned *);
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extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
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/*
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 * wait for a page to complete writing to the cache
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 */
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static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
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						  struct page *page)
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{
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	if (PageFsCache(page))
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		fscache_wait_on_page_write(nfsi->fscache, page);
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}
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/*
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 * release the caching state associated with a page if undergoing complete page
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 * invalidation
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 */
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static inline void nfs_fscache_invalidate_page(struct page *page,
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					       struct inode *inode)
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{
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	if (PageFsCache(page))
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		__nfs_fscache_invalidate_page(page, inode);
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}
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/*
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 * Retrieve a page from an inode data storage object.
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 */
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static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
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					    struct inode *inode,
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					    struct page *page)
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{
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	if (NFS_I(inode)->fscache)
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		return __nfs_readpage_from_fscache(ctx, inode, page);
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	return -ENOBUFS;
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}
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/*
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 * Retrieve a set of pages from an inode data storage object.
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 */
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static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
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					     struct inode *inode,
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					     struct address_space *mapping,
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					     struct list_head *pages,
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					     unsigned *nr_pages)
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{
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	if (NFS_I(inode)->fscache)
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		return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
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						    nr_pages);
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	return -ENOBUFS;
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}
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/*
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 * Store a page newly fetched from the server in an inode data storage object
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 * in the cache.
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 */
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static inline void nfs_readpage_to_fscache(struct inode *inode,
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					   struct page *page,
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					   int sync)
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{
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	if (PageFsCache(page))
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		__nfs_readpage_to_fscache(inode, page, sync);
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}
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/*
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 * indicate the client caching state as readable text
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 */
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static inline const char *nfs_server_fscache_state(struct nfs_server *server)
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{
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	if (server->fscache && (server->options & NFS_OPTION_FSCACHE))
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		return "yes";
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	return "no ";
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}
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#else /* CONFIG_NFS_FSCACHE */
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static inline int nfs_fscache_register(void) { return 0; }
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static inline void nfs_fscache_unregister(void) {}
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static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
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static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
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static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
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static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {}
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static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {}
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static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {}
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static inline void nfs_fscache_set_inode_cookie(struct inode *inode,
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						struct file *filp) {}
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static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {}
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static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
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{
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	return 1; /* True: may release page */
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}
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static inline void nfs_fscache_invalidate_page(struct page *page,
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					       struct inode *inode) {}
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static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
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						  struct page *page) {}
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static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
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					    struct inode *inode,
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					    struct page *page)
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{
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	return -ENOBUFS;
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}
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static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
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					     struct inode *inode,
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					     struct address_space *mapping,
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					     struct list_head *pages,
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					     unsigned *nr_pages)
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{
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	return -ENOBUFS;
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}
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static inline void nfs_readpage_to_fscache(struct inode *inode,
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					   struct page *page, int sync) {}
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static inline const char *nfs_server_fscache_state(struct nfs_server *server)
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{
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	return "no ";
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}
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#endif /* CONFIG_NFS_FSCACHE */
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#endif /* _NFS_FSCACHE_H */
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