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 #define PG_BUSY 0 31 #define PG_NEED_COMMIT 1 32 #define PG_NEED_RESCHED 2 33 34 struct nfs_inode; 35 struct 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 atomic_t wb_complete; /* i/os we're waiting for */ 40 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */ 41 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ 42 wb_pgbase, /* Start of page data */ 43 wb_bytes; /* Length of request */ 44 struct kref wb_kref; /* reference count */ 45 unsigned long wb_flags; 46 struct nfs_writeverf wb_verf; /* Commit cookie */ 47 }; 48 49 struct nfs_pageio_descriptor { 50 struct list_head pg_list; 51 unsigned long pg_bytes_written; 52 size_t pg_count; 53 size_t pg_bsize; 54 unsigned int pg_base; 55 56 struct inode *pg_inode; 57 int (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int); 58 int pg_ioflags; 59 int pg_error; 60 }; 61 62 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 63 64 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 65 struct inode *inode, 66 struct page *page, 67 unsigned int offset, 68 unsigned int count); 69 extern void nfs_clear_request(struct nfs_page *req); 70 extern void nfs_release_request(struct nfs_page *req); 71 72 73 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst, 74 pgoff_t idx_start, unsigned int npages, int tag); 75 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 76 struct inode *inode, 77 int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int), 78 size_t bsize, 79 int how); 80 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 81 struct nfs_page *); 82 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 83 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 84 extern int nfs_wait_on_request(struct nfs_page *); 85 extern void nfs_unlock_request(struct nfs_page *req); 86 extern int nfs_set_page_tag_locked(struct nfs_page *req); 87 extern void nfs_clear_page_tag_locked(struct nfs_page *req); 88 89 90 /* 91 * Lock the page of an asynchronous request without getting a new reference 92 */ 93 static inline int 94 nfs_lock_request_dontget(struct nfs_page *req) 95 { 96 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 97 } 98 99 /** 100 * nfs_list_add_request - Insert a request into a list 101 * @req: request 102 * @head: head of list into which to insert the request. 103 */ 104 static inline void 105 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 106 { 107 list_add_tail(&req->wb_list, head); 108 } 109 110 111 /** 112 * nfs_list_remove_request - Remove a request from its wb_list 113 * @req: request 114 */ 115 static inline void 116 nfs_list_remove_request(struct nfs_page *req) 117 { 118 if (list_empty(&req->wb_list)) 119 return; 120 list_del_init(&req->wb_list); 121 } 122 123 static inline struct nfs_page * 124 nfs_list_entry(struct list_head *head) 125 { 126 return list_entry(head, struct nfs_page, wb_list); 127 } 128 129 static inline 130 loff_t req_offset(struct nfs_page *req) 131 { 132 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 133 } 134 135 #endif /* _LINUX_NFS_PAGE_H */ 136