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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * linux/include/linux/nfs_page.h4 *5 * Copyright (C) 2000 Trond Myklebust6 *7 * NFS page cache wrapper.8 */9 10#ifndef _LINUX_NFS_PAGE_H11#define _LINUX_NFS_PAGE_H12 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 buffer24 */25enum {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 42struct nfs_inode;43struct 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 62struct nfs_pgio_mirror;63struct nfs_pageio_descriptor;64struct 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 77struct nfs_rw_ops {78 struct nfs_pgio_header *(*rw_alloc_header)(void);79 void (*rw_free_header)(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 88struct 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 97struct 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_FSCACHE109 void *pg_netfs;110#endif111 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 16124 125#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))126 127extern 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);132extern 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);136extern void nfs_release_request(struct nfs_page *);137 138 139extern 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);146extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,147 struct nfs_page *);148extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,149 struct nfs_pgio_header *);150extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);151extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);152extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,153 struct nfs_page *prev,154 struct nfs_page *req);155extern void nfs_unlock_request(struct nfs_page *req);156extern void nfs_unlock_and_release_request(struct nfs_page *);157extern void nfs_join_page_group(struct nfs_page *head,158 struct nfs_commit_info *cinfo,159 struct inode *inode);160extern int nfs_page_group_lock(struct nfs_page *);161extern void nfs_page_group_unlock(struct nfs_page *);162extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);163extern int nfs_page_set_headlock(struct nfs_page *req);164extern void nfs_page_clear_headlock(struct nfs_page *req);165extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);166 167/**168 * nfs_page_to_folio - Retrieve a struct folio for the request169 * @req: pointer to a struct nfs_page170 *171 * If a folio was assigned to @req, then return it, otherwise return NULL.172 */173static inline struct folio *nfs_page_to_folio(const struct nfs_page *req)174{175 if (test_bit(PG_FOLIO, &req->wb_flags))176 return req->wb_folio;177 return NULL;178}179 180/**181 * nfs_page_to_page - Retrieve a struct page for the request182 * @req: pointer to a struct nfs_page183 * @pgbase: folio byte offset184 *185 * Return the page containing the byte that is at offset @pgbase relative186 * to the start of the folio.187 * Note: The request starts at offset @req->wb_pgbase.188 */189static inline struct page *nfs_page_to_page(const struct nfs_page *req,190 size_t pgbase)191{192 struct folio *folio = nfs_page_to_folio(req);193 194 if (folio == NULL)195 return req->wb_page;196 return folio_page(folio, pgbase >> PAGE_SHIFT);197}198 199/**200 * nfs_page_to_inode - Retrieve an inode for the request201 * @req: pointer to a struct nfs_page202 */203static inline struct inode *nfs_page_to_inode(const struct nfs_page *req)204{205 struct folio *folio = nfs_page_to_folio(req);206 207 if (folio == NULL)208 return req->wb_page->mapping->host;209 return folio->mapping->host;210}211 212/**213 * nfs_page_max_length - Retrieve the maximum possible length for a request214 * @req: pointer to a struct nfs_page215 *216 * Returns the maximum possible length of a request217 */218static inline size_t nfs_page_max_length(const struct nfs_page *req)219{220 struct folio *folio = nfs_page_to_folio(req);221 222 if (folio == NULL)223 return PAGE_SIZE;224 return folio_size(folio);225}226 227/*228 * Lock the page of an asynchronous request229 */230static inline int231nfs_lock_request(struct nfs_page *req)232{233 return !test_and_set_bit(PG_BUSY, &req->wb_flags);234}235 236/**237 * nfs_list_add_request - Insert a request into a list238 * @req: request239 * @head: head of list into which to insert the request.240 */241static inline void242nfs_list_add_request(struct nfs_page *req, struct list_head *head)243{244 list_add_tail(&req->wb_list, head);245}246 247/**248 * nfs_list_move_request - Move a request to a new list249 * @req: request250 * @head: head of list into which to insert the request.251 */252static inline void253nfs_list_move_request(struct nfs_page *req, struct list_head *head)254{255 list_move_tail(&req->wb_list, head);256}257 258/**259 * nfs_list_remove_request - Remove a request from its wb_list260 * @req: request261 */262static inline void263nfs_list_remove_request(struct nfs_page *req)264{265 if (list_empty(&req->wb_list))266 return;267 list_del_init(&req->wb_list);268}269 270static inline struct nfs_page *271nfs_list_entry(struct list_head *head)272{273 return list_entry(head, struct nfs_page, wb_list);274}275 276static inline loff_t req_offset(const struct nfs_page *req)277{278 return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;279}280 281static inline struct nfs_open_context *282nfs_req_openctx(struct nfs_page *req)283{284 return req->wb_lock_context->open_context;285}286 287#endif /* _LINUX_NFS_PAGE_H */288