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 PG_PNFS_COMMIT, 37 PG_PARTIAL_READ_FAILED, 38 }; 39 40 struct nfs_inode; 41 struct nfs_page { 42 union { 43 struct list_head wb_list; /* Defines state of page: */ 44 struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */ 45 }; 46 struct page *wb_page; /* page to read in/write out */ 47 struct nfs_open_context *wb_context; /* File state context info */ 48 struct nfs_lock_context *wb_lock_context; /* lock context info */ 49 atomic_t wb_complete; /* i/os we're waiting for */ 50 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */ 51 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ 52 wb_pgbase, /* Start of page data */ 53 wb_bytes; /* Length of request */ 54 struct kref wb_kref; /* reference count */ 55 unsigned long wb_flags; 56 struct nfs_writeverf wb_verf; /* Commit cookie */ 57 }; 58 59 struct nfs_pageio_descriptor; 60 struct nfs_pageio_ops { 61 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 62 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *); 63 int (*pg_doio)(struct nfs_pageio_descriptor *); 64 }; 65 66 struct nfs_pageio_descriptor { 67 struct list_head pg_list; 68 unsigned long pg_bytes_written; 69 size_t pg_count; 70 size_t pg_bsize; 71 unsigned int pg_base; 72 unsigned char pg_moreio : 1, 73 pg_recoalesce : 1; 74 75 struct inode *pg_inode; 76 const struct nfs_pageio_ops *pg_ops; 77 int pg_ioflags; 78 int pg_error; 79 const struct rpc_call_ops *pg_rpc_callops; 80 struct pnfs_layout_segment *pg_lseg; 81 }; 82 83 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 84 85 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 86 struct inode *inode, 87 struct page *page, 88 unsigned int offset, 89 unsigned int count); 90 extern void nfs_release_request(struct nfs_page *req); 91 92 93 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst, 94 pgoff_t idx_start, unsigned int npages, int tag); 95 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 96 struct inode *inode, 97 const struct nfs_pageio_ops *pg_ops, 98 size_t bsize, 99 int how); 100 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 101 struct nfs_page *); 102 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 103 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 104 extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 105 struct nfs_page *prev, 106 struct nfs_page *req); 107 extern int nfs_wait_on_request(struct nfs_page *); 108 extern void nfs_unlock_request(struct nfs_page *req); 109 extern int nfs_set_page_tag_locked(struct nfs_page *req); 110 extern void nfs_clear_page_tag_locked(struct nfs_page *req); 111 112 /* 113 * Lock the page of an asynchronous request without getting a new reference 114 */ 115 static inline int 116 nfs_lock_request_dontget(struct nfs_page *req) 117 { 118 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 119 } 120 121 /** 122 * nfs_list_add_request - Insert a request into a list 123 * @req: request 124 * @head: head of list into which to insert the request. 125 */ 126 static inline void 127 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 128 { 129 list_add_tail(&req->wb_list, head); 130 } 131 132 133 /** 134 * nfs_list_remove_request - Remove a request from its wb_list 135 * @req: request 136 */ 137 static inline void 138 nfs_list_remove_request(struct nfs_page *req) 139 { 140 if (list_empty(&req->wb_list)) 141 return; 142 list_del_init(&req->wb_list); 143 } 144 145 static inline struct nfs_page * 146 nfs_list_entry(struct list_head *head) 147 { 148 return list_entry(head, struct nfs_page, wb_list); 149 } 150 151 static inline 152 loff_t req_offset(struct nfs_page *req) 153 { 154 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 155 } 156 157 #endif /* _LINUX_NFS_PAGE_H */ 158