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_FOLIO, /* Tracking a folio (unset for O_DIRECT) */ |
29 | PG_CLEAN, /* write succeeded */ |
30 | PG_COMMIT_TO_DS, /* used by pnfs layouts */ |
31 | PG_INODE_REF, /* extra ref held by inode when in writeback */ |
32 | PG_HEADLOCK, /* page group lock of wb_head */ |
33 | PG_TEARDOWN, /* page group sync for destroy */ |
34 | PG_UNLOCKPAGE, /* page group sync bit in read path */ |
35 | PG_UPTODATE, /* page group sync bit in read path */ |
36 | PG_WB_END, /* page group sync bit in write path */ |
37 | PG_REMOVE, /* page group sync bit in write path */ |
38 | PG_CONTENDED1, /* Is someone waiting for a lock? */ |
39 | PG_CONTENDED2, /* Is someone waiting for a lock? */ |
40 | }; |
41 | |
42 | struct nfs_inode; |
43 | struct nfs_page { |
44 | struct list_head wb_list; /* Defines state of page: */ |
45 | union { |
46 | struct page *wb_page; /* page to read in/write out */ |
47 | struct folio *wb_folio; |
48 | }; |
49 | struct nfs_lock_context *wb_lock_context; /* lock context info */ |
50 | pgoff_t wb_index; /* Offset >> PAGE_SHIFT */ |
51 | unsigned int wb_offset, /* Offset & ~PAGE_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_write_verifier wb_verf; /* Commit cookie */ |
57 | struct nfs_page *wb_this_page; /* list of reqs for this page */ |
58 | struct nfs_page *wb_head; /* head pointer for req list */ |
59 | unsigned short wb_nio; /* Number of I/O attempts */ |
60 | }; |
61 | |
62 | struct nfs_pgio_mirror; |
63 | struct nfs_pageio_descriptor; |
64 | struct nfs_pageio_ops { |
65 | void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); |
66 | size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, |
67 | struct nfs_page *); |
68 | int (*pg_doio)(struct nfs_pageio_descriptor *); |
69 | unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *, |
70 | struct nfs_page *); |
71 | void (*pg_cleanup)(struct nfs_pageio_descriptor *); |
72 | struct nfs_pgio_mirror * |
73 | (*pg_get_mirror)(struct nfs_pageio_descriptor *, u32); |
74 | u32 (*pg_set_mirror)(struct nfs_pageio_descriptor *, u32); |
75 | }; |
76 | |
77 | struct nfs_rw_ops { |
78 | struct nfs_pgio_header *(*)(void); |
79 | void (*)(struct nfs_pgio_header *); |
80 | int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *, |
81 | struct inode *); |
82 | void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *); |
83 | void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *, |
84 | const struct nfs_rpc_ops *, |
85 | struct rpc_task_setup *, int); |
86 | }; |
87 | |
88 | struct nfs_pgio_mirror { |
89 | struct list_head pg_list; |
90 | unsigned long pg_bytes_written; |
91 | size_t pg_count; |
92 | size_t pg_bsize; |
93 | unsigned int pg_base; |
94 | unsigned char pg_recoalesce : 1; |
95 | }; |
96 | |
97 | struct nfs_pageio_descriptor { |
98 | struct inode *pg_inode; |
99 | const struct nfs_pageio_ops *pg_ops; |
100 | const struct nfs_rw_ops *pg_rw_ops; |
101 | int pg_ioflags; |
102 | int pg_error; |
103 | const struct rpc_call_ops *pg_rpc_callops; |
104 | const struct nfs_pgio_completion_ops *pg_completion_ops; |
105 | struct pnfs_layout_segment *pg_lseg; |
106 | struct nfs_io_completion *pg_io_completion; |
107 | struct nfs_direct_req *pg_dreq; |
108 | #ifdef CONFIG_NFS_FSCACHE |
109 | void *pg_netfs; |
110 | #endif |
111 | unsigned int pg_bsize; /* default bsize for mirrors */ |
112 | |
113 | u32 pg_mirror_count; |
114 | struct nfs_pgio_mirror *pg_mirrors; |
115 | struct nfs_pgio_mirror pg_mirrors_static[1]; |
116 | struct nfs_pgio_mirror *pg_mirrors_dynamic; |
117 | u32 pg_mirror_idx; /* current mirror */ |
118 | unsigned short pg_maxretrans; |
119 | unsigned char pg_moreio : 1; |
120 | }; |
121 | |
122 | /* arbitrarily selected limit to number of mirrors */ |
123 | #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16 |
124 | |
125 | #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) |
126 | |
127 | extern struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx, |
128 | struct page *page, |
129 | unsigned int pgbase, |
130 | loff_t offset, |
131 | unsigned int count); |
132 | extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx, |
133 | struct folio *folio, |
134 | unsigned int offset, |
135 | unsigned int count); |
136 | extern void nfs_release_request(struct nfs_page *); |
137 | |
138 | |
139 | extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, |
140 | struct inode *inode, |
141 | const struct nfs_pageio_ops *pg_ops, |
142 | const struct nfs_pgio_completion_ops *compl_ops, |
143 | const struct nfs_rw_ops *rw_ops, |
144 | size_t bsize, |
145 | int how); |
146 | extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, |
147 | struct nfs_page *); |
148 | extern int nfs_pageio_resend(struct nfs_pageio_descriptor *, |
149 | struct nfs_pgio_header *); |
150 | extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); |
151 | extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t); |
152 | extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, |
153 | struct nfs_page *prev, |
154 | struct nfs_page *req); |
155 | extern int nfs_wait_on_request(struct nfs_page *); |
156 | extern void nfs_unlock_request(struct nfs_page *req); |
157 | extern void nfs_unlock_and_release_request(struct nfs_page *); |
158 | extern struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req); |
159 | extern int nfs_page_group_lock_subrequests(struct nfs_page *head); |
160 | extern void nfs_join_page_group(struct nfs_page *head, |
161 | struct nfs_commit_info *cinfo, |
162 | struct inode *inode); |
163 | extern int nfs_page_group_lock(struct nfs_page *); |
164 | extern void nfs_page_group_unlock(struct nfs_page *); |
165 | extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); |
166 | extern int nfs_page_set_headlock(struct nfs_page *req); |
167 | extern void nfs_page_clear_headlock(struct nfs_page *req); |
168 | extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *); |
169 | |
170 | /** |
171 | * nfs_page_to_folio - Retrieve a struct folio for the request |
172 | * @req: pointer to a struct nfs_page |
173 | * |
174 | * If a folio was assigned to @req, then return it, otherwise return NULL. |
175 | */ |
176 | static inline struct folio *nfs_page_to_folio(const struct nfs_page *req) |
177 | { |
178 | if (test_bit(PG_FOLIO, &req->wb_flags)) |
179 | return req->wb_folio; |
180 | return NULL; |
181 | } |
182 | |
183 | /** |
184 | * nfs_page_to_page - Retrieve a struct page for the request |
185 | * @req: pointer to a struct nfs_page |
186 | * @pgbase: folio byte offset |
187 | * |
188 | * Return the page containing the byte that is at offset @pgbase relative |
189 | * to the start of the folio. |
190 | * Note: The request starts at offset @req->wb_pgbase. |
191 | */ |
192 | static inline struct page *nfs_page_to_page(const struct nfs_page *req, |
193 | size_t pgbase) |
194 | { |
195 | struct folio *folio = nfs_page_to_folio(req); |
196 | |
197 | if (folio == NULL) |
198 | return req->wb_page; |
199 | return folio_page(folio, pgbase >> PAGE_SHIFT); |
200 | } |
201 | |
202 | /** |
203 | * nfs_page_to_inode - Retrieve an inode for the request |
204 | * @req: pointer to a struct nfs_page |
205 | */ |
206 | static inline struct inode *nfs_page_to_inode(const struct nfs_page *req) |
207 | { |
208 | struct folio *folio = nfs_page_to_folio(req); |
209 | |
210 | if (folio == NULL) |
211 | return page_file_mapping(page: req->wb_page)->host; |
212 | return folio_file_mapping(folio)->host; |
213 | } |
214 | |
215 | /** |
216 | * nfs_page_max_length - Retrieve the maximum possible length for a request |
217 | * @req: pointer to a struct nfs_page |
218 | * |
219 | * Returns the maximum possible length of a request |
220 | */ |
221 | static inline size_t nfs_page_max_length(const struct nfs_page *req) |
222 | { |
223 | struct folio *folio = nfs_page_to_folio(req); |
224 | |
225 | if (folio == NULL) |
226 | return PAGE_SIZE; |
227 | return folio_size(folio); |
228 | } |
229 | |
230 | /* |
231 | * Lock the page of an asynchronous request |
232 | */ |
233 | static inline int |
234 | nfs_lock_request(struct nfs_page *req) |
235 | { |
236 | return !test_and_set_bit(nr: PG_BUSY, addr: &req->wb_flags); |
237 | } |
238 | |
239 | /** |
240 | * nfs_list_add_request - Insert a request into a list |
241 | * @req: request |
242 | * @head: head of list into which to insert the request. |
243 | */ |
244 | static inline void |
245 | nfs_list_add_request(struct nfs_page *req, struct list_head *head) |
246 | { |
247 | list_add_tail(new: &req->wb_list, head); |
248 | } |
249 | |
250 | /** |
251 | * nfs_list_move_request - Move a request to a new list |
252 | * @req: request |
253 | * @head: head of list into which to insert the request. |
254 | */ |
255 | static inline void |
256 | nfs_list_move_request(struct nfs_page *req, struct list_head *head) |
257 | { |
258 | list_move_tail(list: &req->wb_list, head); |
259 | } |
260 | |
261 | /** |
262 | * nfs_list_remove_request - Remove a request from its wb_list |
263 | * @req: request |
264 | */ |
265 | static inline void |
266 | nfs_list_remove_request(struct nfs_page *req) |
267 | { |
268 | if (list_empty(head: &req->wb_list)) |
269 | return; |
270 | list_del_init(entry: &req->wb_list); |
271 | } |
272 | |
273 | static inline struct nfs_page * |
274 | nfs_list_entry(struct list_head *head) |
275 | { |
276 | return list_entry(head, struct nfs_page, wb_list); |
277 | } |
278 | |
279 | static inline loff_t req_offset(const struct nfs_page *req) |
280 | { |
281 | return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset; |
282 | } |
283 | |
284 | static inline struct nfs_open_context * |
285 | nfs_req_openctx(struct nfs_page *req) |
286 | { |
287 | return req->wb_lock_context->open_context; |
288 | } |
289 | |
290 | #endif /* _LINUX_NFS_PAGE_H */ |
291 | |