LCOV - code coverage report
Current view: top level - include/linux - nfs_page.h (source / functions) Hit Total Coverage
Test: gcov_data_raspi2_real_modules_combined.info Lines: 0 6 0.0 %
Date: 2020-09-30 20:25:40 Functions: 0 0 -
Branches: 0 12 0.0 %

           Branch data     Line data    Source code
       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                 :          0 :         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                 :          0 :         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                 :          0 :         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   [ #  #  #  #  :          0 :         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                 :          0 :         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                 :          0 :         return req->wb_lock_context->open_context;
     206                 :            : }
     207                 :            : 
     208                 :            : #endif /* _LINUX_NFS_PAGE_H */

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