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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | /* |
| 2 | * linux/include/linux/nfs_page.h |
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| 3 | * |
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| 4 | * Copyright (C) 2000 Trond Myklebust |
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| 5 | * |
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| 6 | * NFS page cache wrapper. |
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| 7 | */ |
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| 8 | |||
| 9 | #ifndef _LINUX_NFS_PAGE_H |
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| 10 | #define _LINUX_NFS_PAGE_H |
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| 11 | |||
| 12 | |||
| 13 | #include <linux/list.h> |
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| 14 | #include <linux/pagemap.h> |
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| 15 | #include <linux/wait.h> |
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| 16 | #include <linux/nfs_fs_sb.h> |
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| 17 | #include <linux/sunrpc/auth.h> |
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| 18 | #include <linux/nfs_xdr.h> |
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| 19 | |||
| 20 | /* |
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| 21 | * Valid flags for a dirty buffer |
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| 22 | */ |
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| 23 | #define PG_BUSY 0 |
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| 24 | |||
| 25 | struct nfs_page { |
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| 26 | struct list_head wb_list, /* Defines state of page: */ |
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| 27 | *wb_list_head; /* read/write/commit */ |
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| 28 | struct file *wb_file; |
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| 29 | struct inode *wb_inode; |
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| 30 | struct rpc_cred *wb_cred; |
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| 31 | struct nfs4_state *wb_state; |
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| 32 | struct page *wb_page; /* page to read in/write out */ |
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| 33 | wait_queue_head_t wb_wait; /* wait queue */ |
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| 34 | unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */ |
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| 35 | unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ |
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| 36 | wb_pgbase, /* Start of page data */ |
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| 37 | wb_bytes, /* Length of request */ |
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| 38 | wb_count; /* reference count */ |
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| 39 | unsigned long wb_flags; |
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| 40 | struct nfs_writeverf wb_verf; /* Commit cookie */ |
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| 41 | }; |
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| 42 | |||
| 43 | #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) |
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| 44 | |||
| 45 | extern struct nfs_page *nfs_create_request(struct file *, struct inode *, |
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| 46 | struct page *, |
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| 47 | unsigned int, unsigned int); |
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| 48 | extern void nfs_clear_request(struct nfs_page *req); |
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| 49 | extern void nfs_release_request(struct nfs_page *req); |
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| 50 | |||
| 51 | |||
| 52 | extern void nfs_list_add_request(struct nfs_page *, struct list_head *); |
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| 53 | |||
| 54 | extern int nfs_scan_list(struct list_head *, struct list_head *, |
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| 55 | struct file *, unsigned long, unsigned int); |
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| 56 | extern int nfs_coalesce_requests(struct list_head *, struct list_head *, |
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| 57 | unsigned int); |
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| 58 | extern int nfs_wait_on_request(struct nfs_page *); |
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| 59 | |||
| 60 | extern spinlock_t nfs_wreq_lock; |
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| 61 | |||
| 62 | /* |
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| 63 | * Lock the page of an asynchronous request without incrementing the wb_count |
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| 64 | */ |
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| 65 | static inline int |
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| 66 | nfs_lock_request_dontget(struct nfs_page *req) |
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| 67 | { |
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| 68 | if (test_and_set_bit(PG_BUSY, &req->wb_flags)) |
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| 69 | return 0; |
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| 70 | return 1; |
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| 71 | } |
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| 72 | |||
| 73 | /* |
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| 74 | * Lock the page of an asynchronous request |
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| 75 | */ |
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| 76 | static inline int |
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| 77 | nfs_lock_request(struct nfs_page *req) |
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| 78 | { |
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| 79 | if (test_and_set_bit(PG_BUSY, &req->wb_flags)) |
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| 80 | return 0; |
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| 81 | req->wb_count++; |
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| 82 | return 1; |
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| 83 | } |
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| 84 | |||
| 85 | static inline void |
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| 86 | nfs_unlock_request(struct nfs_page *req) |
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| 87 | { |
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| 88 | if (!NFS_WBACK_BUSY(req)) { |
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| 89 | printk(KERN_ERR "NFS: Invalid unlock attempted\n"); |
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| 90 | BUG(); |
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| 91 | } |
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| 92 | smp_mb__before_clear_bit(); |
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| 93 | clear_bit(PG_BUSY, &req->wb_flags); |
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| 94 | smp_mb__after_clear_bit(); |
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| 95 | if (waitqueue_active(&req->wb_wait)) |
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| 96 | wake_up_all(&req->wb_wait); |
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| 97 | nfs_release_request(req); |
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| 98 | } |
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| 99 | |||
| 100 | /** |
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| 101 | * nfs_list_remove_request - Remove a request from its wb_list |
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| 102 | * @req: request |
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| 103 | */ |
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| 104 | static inline void |
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| 105 | nfs_list_remove_request(struct nfs_page *req) |
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| 106 | { |
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| 107 | if (list_empty(&req->wb_list)) |
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| 108 | return; |
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| 109 | if (!NFS_WBACK_BUSY(req)) { |
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| 110 | printk(KERN_ERR "NFS: unlocked request attempted removed from list!\n"); |
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| 111 | BUG(); |
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| 112 | } |
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| 113 | list_del_init(&req->wb_list); |
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| 114 | req->wb_list_head = NULL; |
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| 115 | } |
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| 116 | |||
| 117 | static inline struct nfs_page * |
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| 118 | nfs_list_entry(struct list_head *head) |
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| 119 | { |
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| 120 | return list_entry(head, struct nfs_page, wb_list); |
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| 121 | } |
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| 122 | |||
| 123 | static inline |
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| 124 | loff_t req_offset(struct nfs_page *req) |
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| 125 | { |
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| 126 | return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; |
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| 127 | } |
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| 128 | |||
| 129 | #endif /* _LINUX_NFS_PAGE_H */ |