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