tools/brcm/K24/hndtools-mipsel-uclibc-4.2.4/include/linux/nfs_page.h

   1 /*
   2  * linux/include/linux/nfs_page.h
   3  *
   4  * Copyright (C) 2000 Trond Myklebust
   5  *
   6  * NFS page cache wrapper.
   7  */
   8
   9 #ifndef _LINUX_NFS_PAGE_H
  10 #define _LINUX_NFS_PAGE_H
  11
  12
  13 #include <linux/list.h>
  14 #include <linux/mm.h>
  15 #include <linux/wait.h>
  16 #include <linux/sunrpc/auth.h>
  17 #include <linux/nfs_xdr.h>
  18
  19 /*
  20  * Valid flags for a dirty buffer
  21  */
  22 #define PG_BUSY                 0
  23
  24 struct nfs_page {
  25         struct list_head        wb_hash,        /* Inode */
  26                                 wb_lru,         /* superblock lru list */
  27                                 wb_list,        /* Defines state of page: */
  28                                 *wb_list_head;  /*      read/write/commit */
  29         struct file             *wb_file;
  30         struct inode            *wb_inode;
  31         struct rpc_cred         *wb_cred;
  32         struct page             *wb_page;       /* page to read in/write out */
  33         wait_queue_head_t       wb_wait;        /* wait queue */
  34         unsigned long           wb_timeout;     /* when to read/write/commit */
  35         unsigned int            wb_offset,      /* Offset of read/write */
  36                                 wb_bytes,       /* Length of request */
  37                                 wb_count;       /* reference count */
  38         unsigned long           wb_flags;
  39         struct nfs_writeverf    wb_verf;        /* Commit cookie */
  40 };
  41
  42 #define NFS_WBACK_BUSY(req)     (test_bit(PG_BUSY,&(req)->wb_flags))
  43
  44 extern  struct nfs_page *nfs_create_request(struct rpc_cred *, struct inode *,
  45                                             struct page *,
  46                                             unsigned int, unsigned int);
  47 extern  void nfs_clear_request(struct nfs_page *req);
  48 extern  void nfs_release_request(struct nfs_page *req);
  49
  50
  51 extern  void nfs_list_add_request(struct nfs_page *, struct list_head *);
  52
  53 extern  int nfs_scan_lru(struct list_head *, struct list_head *, int);
  54 extern  int nfs_scan_lru_timeout(struct list_head *, struct list_head *, int);
  55 extern  int nfs_scan_list(struct list_head *, struct list_head *,
  56                                 unsigned long, unsigned int);
  57 extern  int nfs_coalesce_requests(struct list_head *, struct list_head *,
  58                                   unsigned int);
  59 extern  int nfs_wait_on_request(struct nfs_page *);
  60
  61 extern  spinlock_t nfs_wreq_lock;
  62
  63 /*
  64  * Lock the page of an asynchronous request without incrementing the wb_count
  65  */
  66 static inline int
  67 nfs_lock_request_dontget(struct nfs_page *req)
  68 {
  69         if (test_and_set_bit(PG_BUSY, &req->wb_flags))
  70                 return 0;
  71         return 1;
  72 }
  73
  74 /*
  75  * Lock the page of an asynchronous request
  76  */
  77 static inline int
  78 nfs_lock_request(struct nfs_page *req)
  79 {
  80         if (test_and_set_bit(PG_BUSY, &req->wb_flags))
  81                 return 0;
  82         req->wb_count++;
  83         return 1;
  84 }
  85
  86 static inline void
  87 nfs_unlock_request(struct nfs_page *req)
  88 {
  89         if (!NFS_WBACK_BUSY(req)) {
  90                 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
  91                 BUG();
  92         }
  93         smp_mb__before_clear_bit();
  94         clear_bit(PG_BUSY, &req->wb_flags);
  95         smp_mb__after_clear_bit();
  96         if (waitqueue_active(&req->wb_wait))
  97                 wake_up_all(&req->wb_wait);
  98         nfs_release_request(req);
  99 }
 100
 101 /**
 102  * nfs_list_remove_request - Remove a request from its wb_list
 103  * @req: request
 104  */
 105 static inline void
 106 nfs_list_remove_request(struct nfs_page *req)
 107 {
 108         if (list_empty(&req->wb_list))
 109                 return;
 110         if (!NFS_WBACK_BUSY(req)) {
 111                 printk(KERN_ERR "NFS: unlocked request attempted removed from list!\n");
 112                 BUG();
 113         }
 114         list_del_init(&req->wb_list);
 115         req->wb_list_head = NULL;
 116 }
 117
 118 static inline struct nfs_page *
 119 nfs_list_entry(struct list_head *head)
 120 {
 121         return list_entry(head, struct nfs_page, wb_list);
 122 }
 123
 124 static inline struct nfs_page *
 125 nfs_inode_wb_entry(struct list_head *head)
 126 {
 127         return list_entry(head, struct nfs_page, wb_hash);
 128 }
 129
 130 static inline void
 131 __nfs_add_lru(struct list_head *head, struct nfs_page *req)
 132 {
 133         list_add_tail(&req->wb_lru, head);
 134 }
 135
 136 static inline void
 137 __nfs_del_lru(struct nfs_page *req)
 138 {
 139         if (list_empty(&req->wb_lru))
 140                 return;
 141         list_del_init(&req->wb_lru);
 142 }
 143
 144 static inline struct nfs_page *
 145 nfs_lru_entry(struct list_head *head)
 146 {
 147         return list_entry(head, struct nfs_page, wb_lru);
 148 }
 149
 150 #endif /* _LINUX_NFS_PAGE_H */