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	 e468bae97d
			
		
	
	
		e468bae97d
		
	
	
	
	
		
			
			Currently, if an unstable write completes, we cannot redirty the page in order to reflect a new change in the page data until after we've sent a COMMIT request. This patch allows a page rewrite to proceed without the unnecessary COMMIT step, putting it immediately back onto the dirty page list, undoing the VM unstable write accounting, and removing the NFS_PAGE_TAG_COMMIT tag from the NFS radix tree. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
		
			
				
	
	
		
			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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| 
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| #ifndef _LINUX_NFS_PAGE_H
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| #define _LINUX_NFS_PAGE_H
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| 
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| 
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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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| 
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| #include <linux/kref.h>
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| 
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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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| /*
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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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| 
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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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| 
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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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| 
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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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| 
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| #define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
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| 
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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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| 
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| 
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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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| 
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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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| /**
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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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| 
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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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| 
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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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| 
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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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| 
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| #endif /* _LINUX_NFS_PAGE_H */
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