1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * linux/include/linux/nfs_page.h 4 * 5 * Copyright (C) 2000 Trond Myklebust 6 * 7 * NFS page cache wrapper. 8 */ 9 10 #ifndef _LINUX_NFS_PAGE_H 11 #define _LINUX_NFS_PAGE_H 12 13 14 #include <linux/list.h> 15 #include <linux/pagemap.h> 16 #include <linux/wait.h> 17 #include <linux/sunrpc/auth.h> 18 #include <linux/nfs_xdr.h> 19 20 #include <linux/kref.h> 21 22 /* 23 * Valid flags for a dirty buffer 24 */ 25 enum { 26 PG_BUSY = 0, /* nfs_{un}lock_request */ 27 PG_MAPPED, /* page private set for buffered io */ 28 PG_CLEAN, /* write succeeded */ 29 PG_COMMIT_TO_DS, /* used by pnfs layouts */ 30 PG_INODE_REF, /* extra ref held by inode when in writeback */ 31 PG_HEADLOCK, /* page group lock of wb_head */ 32 PG_TEARDOWN, /* page group sync for destroy */ 33 PG_UNLOCKPAGE, /* page group sync bit in read path */ 34 PG_UPTODATE, /* page group sync bit in read path */ 35 PG_WB_END, /* page group sync bit in write path */ 36 PG_REMOVE, /* page group sync bit in write path */ 37 PG_CONTENDED1, /* Is someone waiting for a lock? */ 38 PG_CONTENDED2, /* Is someone waiting for a lock? */ 39 }; 40 41 struct nfs_inode; 42 struct nfs_page { 43 struct list_head wb_list; /* Defines state of page: */ 44 struct page *wb_page; /* page to read in/write out */ 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 unsigned short wb_nio; /* Number of I/O attempts */ 56 }; 57 58 struct nfs_pageio_descriptor; 59 struct nfs_pageio_ops { 60 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 61 size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, 62 struct nfs_page *); 63 int (*pg_doio)(struct nfs_pageio_descriptor *); 64 unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *, 65 struct nfs_page *); 66 void (*pg_cleanup)(struct nfs_pageio_descriptor *); 67 }; 68 69 struct nfs_rw_ops { 70 struct nfs_pgio_header *(*rw_alloc_header)(void); 71 void (*rw_free_header)(struct nfs_pgio_header *); 72 int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *, 73 struct inode *); 74 void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *); 75 void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *, 76 const struct nfs_rpc_ops *, 77 struct rpc_task_setup *, int); 78 }; 79 80 struct nfs_pgio_mirror { 81 struct list_head pg_list; 82 unsigned long pg_bytes_written; 83 size_t pg_count; 84 size_t pg_bsize; 85 unsigned int pg_base; 86 unsigned char pg_recoalesce : 1; 87 }; 88 89 struct nfs_pageio_descriptor { 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 unsigned short pg_maxretrans; 108 unsigned char pg_moreio : 1; 109 }; 110 111 /* arbitrarily selected limit to number of mirrors */ 112 #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16 113 114 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 115 116 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 117 struct page *page, 118 unsigned int offset, 119 unsigned int count); 120 extern void nfs_release_request(struct nfs_page *); 121 122 123 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 124 struct inode *inode, 125 const struct nfs_pageio_ops *pg_ops, 126 const struct nfs_pgio_completion_ops *compl_ops, 127 const struct nfs_rw_ops *rw_ops, 128 size_t bsize, 129 int how); 130 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 131 struct nfs_page *); 132 extern int nfs_pageio_resend(struct nfs_pageio_descriptor *, 133 struct nfs_pgio_header *); 134 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 135 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 136 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 137 struct nfs_page *prev, 138 struct nfs_page *req); 139 extern int nfs_wait_on_request(struct nfs_page *); 140 extern void nfs_unlock_request(struct nfs_page *req); 141 extern void nfs_unlock_and_release_request(struct nfs_page *); 142 extern int nfs_page_group_lock(struct nfs_page *); 143 extern void nfs_page_group_unlock(struct nfs_page *); 144 extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); 145 extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *); 146 147 /* 148 * Lock the page of an asynchronous request 149 */ 150 static inline int 151 nfs_lock_request(struct nfs_page *req) 152 { 153 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 154 } 155 156 /** 157 * nfs_list_add_request - Insert a request into a list 158 * @req: request 159 * @head: head of list into which to insert the request. 160 */ 161 static inline void 162 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 163 { 164 list_add_tail(&req->wb_list, head); 165 } 166 167 /** 168 * nfs_list_move_request - Move a request to a new list 169 * @req: request 170 * @head: head of list into which to insert the request. 171 */ 172 static inline void 173 nfs_list_move_request(struct nfs_page *req, struct list_head *head) 174 { 175 list_move_tail(&req->wb_list, head); 176 } 177 178 /** 179 * nfs_list_remove_request - Remove a request from its wb_list 180 * @req: request 181 */ 182 static inline void 183 nfs_list_remove_request(struct nfs_page *req) 184 { 185 if (list_empty(&req->wb_list)) 186 return; 187 list_del_init(&req->wb_list); 188 } 189 190 static inline struct nfs_page * 191 nfs_list_entry(struct list_head *head) 192 { 193 return list_entry(head, struct nfs_page, wb_list); 194 } 195 196 static inline 197 loff_t req_offset(struct nfs_page *req) 198 { 199 return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset; 200 } 201 202 static inline struct nfs_open_context * 203 nfs_req_openctx(struct nfs_page *req) 204 { 205 return req->wb_lock_context->open_context; 206 } 207 208 #endif /* _LINUX_NFS_PAGE_H */ 209