Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/pagemap.h> |
| 15 | #include <linux/wait.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/sunrpc/auth.h> |
| 17 | #include <linux/nfs_xdr.h> |
| 18 | |
| 19 | #include <asm/atomic.h> |
| 20 | |
| 21 | /* |
Trond Myklebust | c6a556b | 2005-06-22 17:16:30 +0000 | [diff] [blame] | 22 | * Valid flags for the radix tree |
| 23 | */ |
Trond Myklebust | 3da28eb | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 24 | #define NFS_PAGE_TAG_DIRTY 0 |
Trond Myklebust | c6a556b | 2005-06-22 17:16:30 +0000 | [diff] [blame] | 25 | #define NFS_PAGE_TAG_WRITEBACK 1 |
| 26 | |
| 27 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | * Valid flags for a dirty buffer |
| 29 | */ |
| 30 | #define PG_BUSY 0 |
| 31 | #define PG_NEED_COMMIT 1 |
| 32 | #define PG_NEED_RESCHED 2 |
| 33 | |
Trond Myklebust | 3da28eb | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 34 | struct nfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | struct nfs_page { |
| 36 | struct list_head wb_list, /* Defines state of page: */ |
| 37 | *wb_list_head; /* read/write/commit */ |
| 38 | struct page *wb_page; /* page to read in/write out */ |
| 39 | struct nfs_open_context *wb_context; /* File state context info */ |
| 40 | atomic_t wb_complete; /* i/os we're waiting for */ |
| 41 | unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */ |
| 42 | unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */ |
| 43 | wb_pgbase, /* Start of page data */ |
| 44 | wb_bytes; /* Length of request */ |
| 45 | atomic_t wb_count; /* reference count */ |
| 46 | unsigned long wb_flags; |
| 47 | struct nfs_writeverf wb_verf; /* Commit cookie */ |
| 48 | }; |
| 49 | |
| 50 | #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) |
| 51 | #define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags)) |
| 52 | #define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags)) |
| 53 | |
| 54 | extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, |
| 55 | struct inode *inode, |
| 56 | struct page *page, |
| 57 | unsigned int offset, |
| 58 | unsigned int count); |
| 59 | extern void nfs_clear_request(struct nfs_page *req); |
| 60 | extern void nfs_release_request(struct nfs_page *req); |
| 61 | |
| 62 | |
Trond Myklebust | 3da28eb | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 63 | extern int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst, |
| 64 | unsigned long idx_start, unsigned int npages); |
Trond Myklebust | d2ccddf | 2006-05-31 01:13:38 -0400 | [diff] [blame] | 65 | extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst, |
| 66 | unsigned long idx_start, unsigned int npages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | extern int nfs_coalesce_requests(struct list_head *, struct list_head *, |
| 68 | unsigned int); |
| 69 | extern int nfs_wait_on_request(struct nfs_page *); |
| 70 | extern void nfs_unlock_request(struct nfs_page *req); |
Trond Myklebust | c6a556b | 2005-06-22 17:16:30 +0000 | [diff] [blame] | 71 | extern int nfs_set_page_writeback_locked(struct nfs_page *req); |
| 72 | extern void nfs_clear_page_writeback(struct nfs_page *req); |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
| 75 | /* |
| 76 | * Lock the page of an asynchronous request without incrementing the wb_count |
| 77 | */ |
| 78 | static inline int |
| 79 | nfs_lock_request_dontget(struct nfs_page *req) |
| 80 | { |
Chuck Lever | a911fd9 | 2005-11-30 18:08:59 -0500 | [diff] [blame] | 81 | return !test_and_set_bit(PG_BUSY, &req->wb_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | /* |
| 85 | * Lock the page of an asynchronous request |
| 86 | */ |
| 87 | static inline int |
| 88 | nfs_lock_request(struct nfs_page *req) |
| 89 | { |
| 90 | if (test_and_set_bit(PG_BUSY, &req->wb_flags)) |
| 91 | return 0; |
| 92 | atomic_inc(&req->wb_count); |
| 93 | return 1; |
| 94 | } |
| 95 | |
Trond Myklebust | 3da28eb | 2005-06-22 17:16:31 +0000 | [diff] [blame] | 96 | /** |
| 97 | * nfs_list_add_request - Insert a request into a list |
| 98 | * @req: request |
| 99 | * @head: head of list into which to insert the request. |
| 100 | */ |
| 101 | static inline void |
| 102 | nfs_list_add_request(struct nfs_page *req, struct list_head *head) |
| 103 | { |
| 104 | list_add_tail(&req->wb_list, head); |
| 105 | req->wb_list_head = head; |
| 106 | } |
| 107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | |
| 109 | /** |
| 110 | * nfs_list_remove_request - Remove a request from its wb_list |
| 111 | * @req: request |
| 112 | */ |
| 113 | static inline void |
| 114 | nfs_list_remove_request(struct nfs_page *req) |
| 115 | { |
| 116 | if (list_empty(&req->wb_list)) |
| 117 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | list_del_init(&req->wb_list); |
| 119 | req->wb_list_head = NULL; |
| 120 | } |
| 121 | |
| 122 | static inline int |
| 123 | nfs_defer_commit(struct nfs_page *req) |
| 124 | { |
Chuck Lever | a911fd9 | 2005-11-30 18:08:59 -0500 | [diff] [blame] | 125 | return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | } |
| 127 | |
| 128 | static inline void |
| 129 | nfs_clear_commit(struct nfs_page *req) |
| 130 | { |
| 131 | smp_mb__before_clear_bit(); |
| 132 | clear_bit(PG_NEED_COMMIT, &req->wb_flags); |
| 133 | smp_mb__after_clear_bit(); |
| 134 | } |
| 135 | |
| 136 | static inline int |
| 137 | nfs_defer_reschedule(struct nfs_page *req) |
| 138 | { |
Chuck Lever | a911fd9 | 2005-11-30 18:08:59 -0500 | [diff] [blame] | 139 | return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | } |
| 141 | |
| 142 | static inline void |
| 143 | nfs_clear_reschedule(struct nfs_page *req) |
| 144 | { |
| 145 | smp_mb__before_clear_bit(); |
| 146 | clear_bit(PG_NEED_RESCHED, &req->wb_flags); |
| 147 | smp_mb__after_clear_bit(); |
| 148 | } |
| 149 | |
| 150 | static inline struct nfs_page * |
| 151 | nfs_list_entry(struct list_head *head) |
| 152 | { |
| 153 | return list_entry(head, struct nfs_page, wb_list); |
| 154 | } |
| 155 | |
| 156 | static inline |
| 157 | loff_t req_offset(struct nfs_page *req) |
| 158 | { |
| 159 | return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; |
| 160 | } |
| 161 | |
| 162 | #endif /* _LINUX_NFS_PAGE_H */ |