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_pgio_mirror; 59 struct nfs_pageio_descriptor; 60 struct nfs_pageio_ops { 61 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); 62 size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, 63 struct nfs_page *); 64 int (*pg_doio)(struct nfs_pageio_descriptor *); 65 unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *, 66 struct nfs_page *); 67 void (*pg_cleanup)(struct nfs_pageio_descriptor *); 68 struct nfs_pgio_mirror * 69 (*pg_get_mirror)(struct nfs_pageio_descriptor *, u32); 70 u32 (*pg_set_mirror)(struct nfs_pageio_descriptor *, u32); 71 }; 72 73 struct nfs_rw_ops { 74 struct nfs_pgio_header *(*rw_alloc_header)(void); 75 void (*rw_free_header)(struct nfs_pgio_header *); 76 int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *, 77 struct inode *); 78 void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *); 79 void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *, 80 const struct nfs_rpc_ops *, 81 struct rpc_task_setup *, int); 82 }; 83 84 struct nfs_pgio_mirror { 85 struct list_head pg_list; 86 unsigned long pg_bytes_written; 87 size_t pg_count; 88 size_t pg_bsize; 89 unsigned int pg_base; 90 unsigned char pg_recoalesce : 1; 91 }; 92 93 struct nfs_pageio_descriptor { 94 struct inode *pg_inode; 95 const struct nfs_pageio_ops *pg_ops; 96 const struct nfs_rw_ops *pg_rw_ops; 97 int pg_ioflags; 98 int pg_error; 99 const struct rpc_call_ops *pg_rpc_callops; 100 const struct nfs_pgio_completion_ops *pg_completion_ops; 101 struct pnfs_layout_segment *pg_lseg; 102 struct nfs_io_completion *pg_io_completion; 103 struct nfs_direct_req *pg_dreq; 104 unsigned int pg_bsize; /* default bsize for mirrors */ 105 106 u32 pg_mirror_count; 107 struct nfs_pgio_mirror *pg_mirrors; 108 struct nfs_pgio_mirror pg_mirrors_static[1]; 109 struct nfs_pgio_mirror *pg_mirrors_dynamic; 110 u32 pg_mirror_idx; /* current mirror */ 111 unsigned short pg_maxretrans; 112 unsigned char pg_moreio : 1; 113 }; 114 115 /* arbitrarily selected limit to number of mirrors */ 116 #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16 117 118 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) 119 120 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, 121 struct page *page, 122 unsigned int offset, 123 unsigned int count); 124 extern void nfs_release_request(struct nfs_page *); 125 126 127 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, 128 struct inode *inode, 129 const struct nfs_pageio_ops *pg_ops, 130 const struct nfs_pgio_completion_ops *compl_ops, 131 const struct nfs_rw_ops *rw_ops, 132 size_t bsize, 133 int how); 134 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, 135 struct nfs_page *); 136 extern int nfs_pageio_resend(struct nfs_pageio_descriptor *, 137 struct nfs_pgio_header *); 138 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); 139 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); 140 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, 141 struct nfs_page *prev, 142 struct nfs_page *req); 143 extern int nfs_wait_on_request(struct nfs_page *); 144 extern void nfs_unlock_request(struct nfs_page *req); 145 extern void nfs_unlock_and_release_request(struct nfs_page *); 146 extern struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req); 147 extern int nfs_page_group_lock_subrequests(struct nfs_page *head); 148 extern void nfs_join_page_group(struct nfs_page *head, struct inode *inode); 149 extern int nfs_page_group_lock(struct nfs_page *); 150 extern void nfs_page_group_unlock(struct nfs_page *); 151 extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); 152 extern int nfs_page_set_headlock(struct nfs_page *req); 153 extern void nfs_page_clear_headlock(struct nfs_page *req); 154 extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *); 155 156 /* 157 * Lock the page of an asynchronous request 158 */ 159 static inline int 160 nfs_lock_request(struct nfs_page *req) 161 { 162 return !test_and_set_bit(PG_BUSY, &req->wb_flags); 163 } 164 165 /** 166 * nfs_list_add_request - Insert a request into a list 167 * @req: request 168 * @head: head of list into which to insert the request. 169 */ 170 static inline void 171 nfs_list_add_request(struct nfs_page *req, struct list_head *head) 172 { 173 list_add_tail(&req->wb_list, head); 174 } 175 176 /** 177 * nfs_list_move_request - Move a request to a new list 178 * @req: request 179 * @head: head of list into which to insert the request. 180 */ 181 static inline void 182 nfs_list_move_request(struct nfs_page *req, struct list_head *head) 183 { 184 list_move_tail(&req->wb_list, head); 185 } 186 187 /** 188 * nfs_list_remove_request - Remove a request from its wb_list 189 * @req: request 190 */ 191 static inline void 192 nfs_list_remove_request(struct nfs_page *req) 193 { 194 if (list_empty(&req->wb_list)) 195 return; 196 list_del_init(&req->wb_list); 197 } 198 199 static inline struct nfs_page * 200 nfs_list_entry(struct list_head *head) 201 { 202 return list_entry(head, struct nfs_page, wb_list); 203 } 204 205 static inline loff_t req_offset(const struct nfs_page *req) 206 { 207 return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset; 208 } 209 210 static inline struct nfs_open_context * 211 nfs_req_openctx(struct nfs_page *req) 212 { 213 return req->wb_lock_context->open_context; 214 } 215 216 #endif /* _LINUX_NFS_PAGE_H */ 217