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 when in writeback */ 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 PG_CONTENDED1, /* Is someone waiting for a lock? */ 37 PG_CONTENDED2, /* Is someone waiting for a lock? */ 38 }; 39 40 struct nfs_inode; 41 struct nfs_page { 42 struct list_head wb_list; /* Defines state of page: */ 43 struct page *wb_page; /* page to read in/write out */ 44 struct nfs_open_context *wb_context; /* File state context info */ 45 struct nfs_lock_context *wb_lock_context; /* lock context info */ 46 pgoff_t wb_index; /* Offset >> PAGE_SHIFT */ 47 unsigned int wb_offset, /* Offset & ~PAGE_MASK */ 48 wb_pgbase, /* Start of page data */ 49 wb_bytes; /* Length of request */ 50 struct kref wb_kref; /* reference count */ 51 unsigned long wb_flags; 52 struct nfs_write_verifier wb_verf; /* Commit cookie */ 53 struct nfs_page *wb_this_page; /* list of reqs for this page */ 54 struct nfs_page *wb_head; /* head pointer for req list */ 55 }; 56 57 struct nfs_pageio_descriptor; 58 struct nfs_pageio_ops { 59 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 60 size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, 61 struct nfs_page *); 62 int (*pg_doio)(struct nfs_pageio_descriptor *); 63 unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *, 64 struct nfs_page *); 65 void (*pg_cleanup)(struct nfs_pageio_descriptor *); 66 }; 67 68 struct nfs_rw_ops { 69 struct nfs_pgio_header *(*rw_alloc_header)(void); 70 void (*rw_free_header)(struct nfs_pgio_header *); 71 int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *, 72 struct inode *); 73 void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *); 74 void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *, 75 const struct nfs_rpc_ops *, 76 struct rpc_task_setup *, int); 77 }; 78 79 struct nfs_pgio_mirror { 80 struct list_head pg_list; 81 unsigned long pg_bytes_written; 82 size_t pg_count; 83 size_t pg_bsize; 84 unsigned int pg_base; 85 unsigned char pg_recoalesce : 1; 86 }; 87 88 struct nfs_pageio_descriptor { 89 unsigned char pg_moreio : 1; 90 struct inode *pg_inode; 91 const struct nfs_pageio_ops *pg_ops; 92 const struct nfs_rw_ops *pg_rw_ops; 93 int pg_ioflags; 94 int pg_error; 95 const struct rpc_call_ops *pg_rpc_callops; 96 const struct nfs_pgio_completion_ops *pg_completion_ops; 97 struct pnfs_layout_segment *pg_lseg; 98 struct nfs_io_completion *pg_io_completion; 99 struct nfs_direct_req *pg_dreq; 100 unsigned int pg_bsize; /* default bsize for mirrors */ 101 102 u32 pg_mirror_count; 103 struct nfs_pgio_mirror *pg_mirrors; 104 struct nfs_pgio_mirror pg_mirrors_static[1]; 105 struct nfs_pgio_mirror *pg_mirrors_dynamic; 106 u32 pg_mirror_idx; /* current mirror */ 107 }; 108 109 /* arbitrarily selected limit to number of mirrors */ 110 #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16 111 112 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 113 114 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 115 struct page *page, 116 struct nfs_page *last, 117 unsigned int offset, 118 unsigned int count); 119 extern void nfs_release_request(struct nfs_page *); 120 121 122 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 123 struct inode *inode, 124 const struct nfs_pageio_ops *pg_ops, 125 const struct nfs_pgio_completion_ops *compl_ops, 126 const struct nfs_rw_ops *rw_ops, 127 size_t bsize, 128 int how); 129 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 130 struct nfs_page *); 131 extern int nfs_pageio_resend(struct nfs_pageio_descriptor *, 132 struct nfs_pgio_header *); 133 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 134 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 135 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 136 struct nfs_page *prev, 137 struct nfs_page *req); 138 extern int nfs_wait_on_request(struct nfs_page *); 139 extern void nfs_unlock_request(struct nfs_page *req); 140 extern void nfs_unlock_and_release_request(struct nfs_page *); 141 extern int nfs_page_group_lock(struct nfs_page *); 142 extern void nfs_page_group_unlock(struct nfs_page *); 143 extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); 144 extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *); 145 146 /* 147 * Lock the page of an asynchronous request 148 */ 149 static inline int 150 nfs_lock_request(struct nfs_page *req) 151 { 152 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 153 } 154 155 /** 156 * nfs_list_add_request - Insert a request into a list 157 * @req: request 158 * @head: head of list into which to insert the request. 159 */ 160 static inline void 161 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 162 { 163 list_add_tail(&req->wb_list, head); 164 } 165 166 167 /** 168 * nfs_list_remove_request - Remove a request from its wb_list 169 * @req: request 170 */ 171 static inline void 172 nfs_list_remove_request(struct nfs_page *req) 173 { 174 if (list_empty(&req->wb_list)) 175 return; 176 list_del_init(&req->wb_list); 177 } 178 179 static inline struct nfs_page * 180 nfs_list_entry(struct list_head *head) 181 { 182 return list_entry(head, struct nfs_page, wb_list); 183 } 184 185 static inline 186 loff_t req_offset(struct nfs_page *req) 187 { 188 return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset; 189 } 190 191 #endif /* _LINUX_NFS_PAGE_H */ 192