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 a dirty buffer 23 */ 24 enum { 25 PG_BUSY = 0, /* nfs_{un}lock_request */ 26 PG_MAPPED, /* page private set for buffered io */ 27 PG_CLEAN, /* write succeeded */ 28 PG_COMMIT_TO_DS, /* used by pnfs layouts */ 29 PG_INODE_REF, /* extra ref held by inode (head req only) */ 30 PG_HEADLOCK, /* page group lock of wb_head */ 31 PG_TEARDOWN, /* page group sync for destroy */ 32 PG_UNLOCKPAGE, /* page group sync bit in read path */ 33 PG_UPTODATE, /* page group sync bit in read path */ 34 PG_WB_END, /* page group sync bit in write path */ 35 PG_REMOVE, /* page group sync bit in write path */ 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 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_write_verifier wb_verf; /* Commit cookie */ 51 struct nfs_page *wb_this_page; /* list of reqs for this page */ 52 struct nfs_page *wb_head; /* head pointer for req list */ 53 }; 54 55 struct nfs_pageio_descriptor; 56 struct nfs_pageio_ops { 57 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 58 size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, 59 struct nfs_page *); 60 int (*pg_doio)(struct nfs_pageio_descriptor *); 61 }; 62 63 struct nfs_rw_ops { 64 const fmode_t rw_mode; 65 struct nfs_rw_header *(*rw_alloc_header)(void); 66 void (*rw_free_header)(struct nfs_rw_header *); 67 void (*rw_release)(struct nfs_pgio_data *); 68 int (*rw_done)(struct rpc_task *, struct nfs_pgio_data *, struct inode *); 69 void (*rw_result)(struct rpc_task *, struct nfs_pgio_data *); 70 void (*rw_initiate)(struct nfs_pgio_data *, struct rpc_message *, 71 struct rpc_task_setup *, int); 72 }; 73 74 struct nfs_pageio_descriptor { 75 struct list_head pg_list; 76 unsigned long pg_bytes_written; 77 size_t pg_count; 78 size_t pg_bsize; 79 unsigned int pg_base; 80 unsigned char pg_moreio : 1, 81 pg_recoalesce : 1; 82 83 struct inode *pg_inode; 84 const struct nfs_pageio_ops *pg_ops; 85 const struct nfs_rw_ops *pg_rw_ops; 86 int pg_ioflags; 87 int pg_error; 88 const struct rpc_call_ops *pg_rpc_callops; 89 const struct nfs_pgio_completion_ops *pg_completion_ops; 90 struct pnfs_layout_segment *pg_lseg; 91 struct nfs_direct_req *pg_dreq; 92 void *pg_layout_private; 93 }; 94 95 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 96 97 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 98 struct page *page, 99 struct nfs_page *last, 100 unsigned int offset, 101 unsigned int count); 102 extern void nfs_release_request(struct nfs_page *); 103 104 105 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 106 struct inode *inode, 107 const struct nfs_pageio_ops *pg_ops, 108 const struct nfs_pgio_completion_ops *compl_ops, 109 const struct nfs_rw_ops *rw_ops, 110 size_t bsize, 111 int how); 112 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 113 struct nfs_page *); 114 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 115 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 116 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 117 struct nfs_page *prev, 118 struct nfs_page *req); 119 extern int nfs_wait_on_request(struct nfs_page *); 120 extern void nfs_unlock_request(struct nfs_page *req); 121 extern void nfs_unlock_and_release_request(struct nfs_page *); 122 extern void nfs_page_group_lock(struct nfs_page *); 123 extern void nfs_page_group_unlock(struct nfs_page *); 124 extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); 125 126 /* 127 * Lock the page of an asynchronous request 128 */ 129 static inline int 130 nfs_lock_request(struct nfs_page *req) 131 { 132 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 133 } 134 135 /** 136 * nfs_list_add_request - Insert a request into a list 137 * @req: request 138 * @head: head of list into which to insert the request. 139 */ 140 static inline void 141 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 142 { 143 list_add_tail(&req->wb_list, head); 144 } 145 146 147 /** 148 * nfs_list_remove_request - Remove a request from its wb_list 149 * @req: request 150 */ 151 static inline void 152 nfs_list_remove_request(struct nfs_page *req) 153 { 154 if (list_empty(&req->wb_list)) 155 return; 156 list_del_init(&req->wb_list); 157 } 158 159 static inline struct nfs_page * 160 nfs_list_entry(struct list_head *head) 161 { 162 return list_entry(head, struct nfs_page, wb_list); 163 } 164 165 static inline 166 loff_t req_offset(struct nfs_page *req) 167 { 168 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; 169 } 170 171 #endif /* _LINUX_NFS_PAGE_H */ 172