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 */ 24 enum { 25 PG_BUSY = 0, 26 PG_MAPPED, 27 PG_CLEAN, 28 PG_NEED_COMMIT, 29 PG_NEED_RESCHED, 30 PG_COMMIT_TO_DS, 31 }; 32 33 struct nfs_inode; 34 struct nfs_page { 35 struct list_head wb_list; /* Defines state of page: */ 36 struct page *wb_page; /* page to read in/write out */ 37 struct nfs_open_context *wb_context; /* File state context info */ 38 struct nfs_lock_context *wb_lock_context; /* lock context info */ 39 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */ 40 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ 41 wb_pgbase, /* Start of page data */ 42 wb_bytes; /* Length of request */ 43 struct kref wb_kref; /* reference count */ 44 unsigned long wb_flags; 45 struct nfs_write_verifier wb_verf; /* Commit cookie */ 46 }; 47 48 struct nfs_pageio_descriptor; 49 struct nfs_pageio_ops { 50 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 51 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *); 52 int (*pg_doio)(struct nfs_pageio_descriptor *); 53 }; 54 55 struct nfs_pageio_descriptor { 56 struct list_head pg_list; 57 unsigned long pg_bytes_written; 58 size_t pg_count; 59 size_t pg_bsize; 60 unsigned int pg_base; 61 unsigned char pg_moreio : 1, 62 pg_recoalesce : 1; 63 64 struct inode *pg_inode; 65 const struct nfs_pageio_ops *pg_ops; 66 int pg_ioflags; 67 int pg_error; 68 const struct rpc_call_ops *pg_rpc_callops; 69 const struct nfs_pgio_completion_ops *pg_completion_ops; 70 struct pnfs_layout_segment *pg_lseg; 71 struct nfs_direct_req *pg_dreq; 72 void *pg_layout_private; 73 }; 74 75 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 76 77 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 78 struct inode *inode, 79 struct page *page, 80 unsigned int offset, 81 unsigned int count); 82 extern void nfs_release_request(struct nfs_page *req); 83 84 85 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 86 struct inode *inode, 87 const struct nfs_pageio_ops *pg_ops, 88 const struct nfs_pgio_completion_ops *compl_ops, 89 size_t bsize, 90 int how); 91 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 92 struct nfs_page *); 93 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 94 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 95 extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 96 struct nfs_page *prev, 97 struct nfs_page *req); 98 extern int nfs_wait_on_request(struct nfs_page *); 99 extern void nfs_unlock_request(struct nfs_page *req); 100 extern void nfs_unlock_and_release_request(struct nfs_page *req); 101 102 /* 103 * Lock the page of an asynchronous request 104 */ 105 static inline int 106 nfs_lock_request(struct nfs_page *req) 107 { 108 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 109 } 110 111 /** 112 * nfs_list_add_request - Insert a request into a list 113 * @req: request 114 * @head: head of list into which to insert the request. 115 */ 116 static inline void 117 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 118 { 119 list_add_tail(&req->wb_list, head); 120 } 121 122 123 /** 124 * nfs_list_remove_request - Remove a request from its wb_list 125 * @req: request 126 */ 127 static inline void 128 nfs_list_remove_request(struct nfs_page *req) 129 { 130 if (list_empty(&req->wb_list)) 131 return; 132 list_del_init(&req->wb_list); 133 } 134 135 static inline struct nfs_page * 136 nfs_list_entry(struct list_head *head) 137 { 138 return list_entry(head, struct nfs_page, wb_list); 139 } 140 141 static inline 142 loff_t req_offset(struct nfs_page *req) 143 { 144 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 145 } 146 147 #endif /* _LINUX_NFS_PAGE_H */ 148