1/* 2 * linux/include/linux/nfs_page.h 3 * 4 * Copyright (C) 2000 Trond Myklebust 5 * 6 * NFS page cache wrapper. 7 */ 8 9#ifndef _LINUX_NFS_PAGE_H 10#define _LINUX_NFS_PAGE_H 11 12 13#include <linux/list.h> 14#include <linux/pagemap.h> 15#include <linux/wait.h> 16#include <linux/sunrpc/auth.h> 17#include <linux/nfs_xdr.h> 18 19#include <linux/kref.h> 20 21/* 22 * Valid flags for a dirty buffer 23 */ 24enum { 25 PG_BUSY = 0, 26 PG_MAPPED, 27 PG_CLEAN, 28 PG_NEED_COMMIT, 29 PG_NEED_RESCHED, 30 PG_PARTIAL_READ_FAILED, 31 PG_COMMIT_TO_DS, 32}; 33 34struct nfs_inode; 35struct nfs_page { 36 struct list_head wb_list; /* Defines state of page: */ 37 struct page *wb_page; /* page to read in/write out */ 38 struct nfs_open_context *wb_context; /* File state context info */ 39 struct nfs_lock_context *wb_lock_context; /* lock context info */ 40 atomic_t wb_complete; /* i/os we're waiting for */ 41 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */ 42 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ 43 wb_pgbase, /* Start of page data */ 44 wb_bytes; /* Length of request */ 45 struct kref wb_kref; /* reference count */ 46 unsigned long wb_flags; 47 struct nfs_writeverf wb_verf; /* Commit cookie */ 48}; 49 50struct nfs_pageio_descriptor; 51struct nfs_pageio_ops { 52 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 53 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *); 54 int (*pg_doio)(struct nfs_pageio_descriptor *); 55}; 56 57struct nfs_pageio_descriptor { 58 struct list_head pg_list; 59 unsigned long pg_bytes_written; 60 size_t pg_count; 61 size_t pg_bsize; 62 unsigned int pg_base; 63 unsigned char pg_moreio : 1, 64 pg_recoalesce : 1; 65 66 struct inode *pg_inode; 67 const struct nfs_pageio_ops *pg_ops; 68 int pg_ioflags; 69 int pg_error; 70 const struct rpc_call_ops *pg_rpc_callops; 71 struct pnfs_layout_segment *pg_lseg; 72}; 73 74#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 75 76extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 77 struct inode *inode, 78 struct page *page, 79 unsigned int offset, 80 unsigned int count); 81extern void nfs_release_request(struct nfs_page *req); 82 83 84extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 85 struct inode *inode, 86 const struct nfs_pageio_ops *pg_ops, 87 size_t bsize, 88 int how); 89extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 90 struct nfs_page *); 91extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 92extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 93extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 94 struct nfs_page *prev, 95 struct nfs_page *req); 96extern int nfs_wait_on_request(struct nfs_page *); 97extern void nfs_unlock_request(struct nfs_page *req); 98 99/* 100 * Lock the page of an asynchronous request without getting a new reference 101 */ 102static inline int 103nfs_lock_request_dontget(struct nfs_page *req) 104{ 105 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 106} 107 108static inline int 109nfs_lock_request(struct nfs_page *req) 110{ 111 if (test_and_set_bit(PG_BUSY, &req->wb_flags)) 112 return 0; 113 kref_get(&req->wb_kref); 114 return 1; 115} 116 117 118/** 119 * nfs_list_add_request - Insert a request into a list 120 * @req: request 121 * @head: head of list into which to insert the request. 122 */ 123static inline void 124nfs_list_add_request(struct nfs_page *req, struct list_head *head) 125{ 126 list_add_tail(&req->wb_list, head); 127} 128 129 130/** 131 * nfs_list_remove_request - Remove a request from its wb_list 132 * @req: request 133 */ 134static inline void 135nfs_list_remove_request(struct nfs_page *req) 136{ 137 if (list_empty(&req->wb_list)) 138 return; 139 list_del_init(&req->wb_list); 140} 141 142static inline struct nfs_page * 143nfs_list_entry(struct list_head *head) 144{ 145 return list_entry(head, struct nfs_page, wb_list); 146} 147 148static inline 149loff_t req_offset(struct nfs_page *req) 150{ 151 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 152} 153 154#endif /* _LINUX_NFS_PAGE_H */ 155