139 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			139 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * linux/include/linux/nfs_page.h
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 *
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 * Copyright (C) 2000 Trond Myklebust
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 *
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 * NFS page cache wrapper.
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 */
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#ifndef _LINUX_NFS_PAGE_H
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#define _LINUX_NFS_PAGE_H
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#include <linux/list.h>
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#include <linux/pagemap.h>
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#include <linux/wait.h>
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#include <linux/sunrpc/auth.h>
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#include <linux/nfs_xdr.h>
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#include <linux/kref.h>
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/*
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 * Valid flags for the radix tree
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 */
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#define NFS_PAGE_TAG_LOCKED	0
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#define NFS_PAGE_TAG_COMMIT	1
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/*
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 * Valid flags for a dirty buffer
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 */
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enum {
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	PG_BUSY = 0,
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	PG_CLEAN,
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	PG_NEED_COMMIT,
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	PG_NEED_RESCHED,
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};
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struct nfs_inode;
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struct nfs_page {
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	struct list_head	wb_list;	/* Defines state of page: */
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	struct page		*wb_page;	/* page to read in/write out */
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	struct nfs_open_context	*wb_context;	/* File state context info */
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	atomic_t		wb_complete;	/* i/os we're waiting for */
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	pgoff_t			wb_index;	/* Offset >> PAGE_CACHE_SHIFT */
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	unsigned int		wb_offset,	/* Offset & ~PAGE_CACHE_MASK */
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				wb_pgbase,	/* Start of page data */
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				wb_bytes;	/* Length of request */
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	struct kref		wb_kref;	/* reference count */
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	unsigned long		wb_flags;
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	struct nfs_writeverf	wb_verf;	/* Commit cookie */
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};
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struct nfs_pageio_descriptor {
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	struct list_head	pg_list;
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	unsigned long		pg_bytes_written;
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	size_t			pg_count;
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	size_t			pg_bsize;
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	unsigned int		pg_base;
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	struct inode		*pg_inode;
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	int			(*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
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	int 			pg_ioflags;
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	int			pg_error;
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};
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#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
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extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
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					    struct inode *inode,
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					    struct page *page,
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					    unsigned int offset,
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					    unsigned int count);
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extern	void nfs_clear_request(struct nfs_page *req);
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extern	void nfs_release_request(struct nfs_page *req);
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extern	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
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			  pgoff_t idx_start, unsigned int npages, int tag);
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extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
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			     struct inode *inode,
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			     int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
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			     size_t bsize,
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			     int how);
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extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
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				   struct nfs_page *);
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extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
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extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
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extern  int nfs_wait_on_request(struct nfs_page *);
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extern	void nfs_unlock_request(struct nfs_page *req);
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extern	int nfs_set_page_tag_locked(struct nfs_page *req);
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extern  void nfs_clear_page_tag_locked(struct nfs_page *req);
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/*
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 * Lock the page of an asynchronous request without getting a new reference
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 */
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static inline int
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nfs_lock_request_dontget(struct nfs_page *req)
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{
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	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
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}
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/**
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 * nfs_list_add_request - Insert a request into a list
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 * @req: request
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 * @head: head of list into which to insert the request.
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 */
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static inline void
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nfs_list_add_request(struct nfs_page *req, struct list_head *head)
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{
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	list_add_tail(&req->wb_list, head);
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}
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/**
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 * nfs_list_remove_request - Remove a request from its wb_list
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 * @req: request
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 */
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static inline void
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nfs_list_remove_request(struct nfs_page *req)
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{
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	if (list_empty(&req->wb_list))
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		return;
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	list_del_init(&req->wb_list);
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}
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static inline struct nfs_page *
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nfs_list_entry(struct list_head *head)
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{
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	return list_entry(head, struct nfs_page, wb_list);
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}
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static inline
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loff_t req_offset(struct nfs_page *req)
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{
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	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
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}
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#endif /* _LINUX_NFS_PAGE_H */
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