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