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 the radix tree 23 */ 24 #define NFS_PAGE_TAG_LOCKED 0 25 #define NFS_PAGE_TAG_COMMIT 1 26 27 /* 28 * Valid flags for a dirty buffer 29 */ 30 enum { 31 PG_BUSY = 0, 32 PG_MAPPED, 33 PG_CLEAN, 34 PG_NEED_COMMIT, 35 PG_NEED_RESCHED, 36 }; 37 38 struct nfs_inode; 39 struct nfs_page { 40 struct list_head wb_list; /* Defines state of page: */ 41 struct page *wb_page; /* page to read in/write out */ 42 struct nfs_open_context *wb_context; /* File state context info */ 43 struct nfs_lock_context *wb_lock_context; /* lock context info */ 44 atomic_t wb_complete; /* i/os we're waiting for */ 45 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */ 46 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ 47 wb_pgbase, /* Start of page data */ 48 wb_bytes; /* Length of request */ 49 struct kref wb_kref; /* reference count */ 50 unsigned long wb_flags; 51 struct nfs_writeverf wb_verf; /* Commit cookie */ 52 }; 53 54 struct nfs_pageio_descriptor { 55 struct list_head pg_list; 56 unsigned long pg_bytes_written; 57 size_t pg_count; 58 size_t pg_bsize; 59 unsigned int pg_base; 60 61 struct inode *pg_inode; 62 int (*pg_doio)(struct nfs_pageio_descriptor *); 63 int pg_ioflags; 64 int pg_error; 65 struct pnfs_layout_segment *pg_lseg; 66 int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *); 67 }; 68 69 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 70 71 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 72 struct inode *inode, 73 struct page *page, 74 unsigned int offset, 75 unsigned int count); 76 extern void nfs_clear_request(struct nfs_page *req); 77 extern void nfs_release_request(struct nfs_page *req); 78 79 80 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst, 81 pgoff_t idx_start, unsigned int npages, int tag); 82 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 83 struct inode *inode, 84 int (*doio)(struct nfs_pageio_descriptor *desc), 85 size_t bsize, 86 int how); 87 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 88 struct nfs_page *); 89 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 90 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 91 extern int nfs_wait_on_request(struct nfs_page *); 92 extern void nfs_unlock_request(struct nfs_page *req); 93 extern int nfs_set_page_tag_locked(struct nfs_page *req); 94 extern void nfs_clear_page_tag_locked(struct nfs_page *req); 95 96 97 /* 98 * Lock the page of an asynchronous request without getting a new reference 99 */ 100 static inline int 101 nfs_lock_request_dontget(struct nfs_page *req) 102 { 103 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 104 } 105 106 /** 107 * nfs_list_add_request - Insert a request into a list 108 * @req: request 109 * @head: head of list into which to insert the request. 110 */ 111 static inline void 112 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 113 { 114 list_add_tail(&req->wb_list, head); 115 } 116 117 118 /** 119 * nfs_list_remove_request - Remove a request from its wb_list 120 * @req: request 121 */ 122 static inline void 123 nfs_list_remove_request(struct nfs_page *req) 124 { 125 if (list_empty(&req->wb_list)) 126 return; 127 list_del_init(&req->wb_list); 128 } 129 130 static inline struct nfs_page * 131 nfs_list_entry(struct list_head *head) 132 { 133 return list_entry(head, struct nfs_page, wb_list); 134 } 135 136 static inline 137 loff_t req_offset(struct nfs_page *req) 138 { 139 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 140 } 141 142 #endif /* _LINUX_NFS_PAGE_H */ 143