163 lines
4.0 KiB
C
163 lines
4.0 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 <asm/atomic.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_DIRTY 0
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#define NFS_PAGE_TAG_WRITEBACK 1
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/*
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* Valid flags for a dirty buffer
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*/
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#define PG_BUSY 0
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#define PG_NEED_COMMIT 1
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#define PG_NEED_RESCHED 2
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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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*wb_list_head; /* read/write/commit */
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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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unsigned long 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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atomic_t wb_count; /* 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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#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
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#define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
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#define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(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_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
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unsigned long idx_start, unsigned int npages);
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extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
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unsigned long idx_start, unsigned int npages);
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extern int nfs_coalesce_requests(struct list_head *, struct list_head *,
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unsigned int);
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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_writeback_locked(struct nfs_page *req);
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extern void nfs_clear_page_writeback(struct nfs_page *req);
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/*
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* Lock the page of an asynchronous request without incrementing the wb_count
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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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* Lock the page of an asynchronous request
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*/
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static inline int
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nfs_lock_request(struct nfs_page *req)
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{
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if (test_and_set_bit(PG_BUSY, &req->wb_flags))
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return 0;
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atomic_inc(&req->wb_count);
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return 1;
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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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req->wb_list_head = 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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req->wb_list_head = NULL;
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}
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static inline int
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nfs_defer_commit(struct nfs_page *req)
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{
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return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags);
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}
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static inline void
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nfs_clear_commit(struct nfs_page *req)
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{
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smp_mb__before_clear_bit();
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clear_bit(PG_NEED_COMMIT, &req->wb_flags);
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smp_mb__after_clear_bit();
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}
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static inline int
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nfs_defer_reschedule(struct nfs_page *req)
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{
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return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags);
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}
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static inline void
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nfs_clear_reschedule(struct nfs_page *req)
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{
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smp_mb__before_clear_bit();
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clear_bit(PG_NEED_RESCHED, &req->wb_flags);
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smp_mb__after_clear_bit();
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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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