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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 LT |
18 | #ifndef __XFS_BUF_H__ |
19 | #define __XFS_BUF_H__ | |
20 | ||
1da177e4 LT |
21 | #include <linux/list.h> |
22 | #include <linux/types.h> | |
23 | #include <linux/spinlock.h> | |
1da177e4 LT |
24 | #include <linux/mm.h> |
25 | #include <linux/fs.h> | |
26 | #include <linux/buffer_head.h> | |
27 | #include <linux/uio.h> | |
28 | ||
29 | /* | |
30 | * Base types | |
31 | */ | |
32 | ||
ce8e922c NS |
33 | #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) |
34 | ||
ce8e922c NS |
35 | typedef enum { |
36 | XBRW_READ = 1, /* transfer into target memory */ | |
37 | XBRW_WRITE = 2, /* transfer from target memory */ | |
38 | XBRW_ZERO = 3, /* Zero target memory */ | |
39 | } xfs_buf_rw_t; | |
40 | ||
807cbbdb CH |
41 | #define XBF_READ (1 << 0) /* buffer intended for reading from device */ |
42 | #define XBF_WRITE (1 << 1) /* buffer intended for writing to device */ | |
1d5ae5df | 43 | #define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */ |
807cbbdb CH |
44 | #define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */ |
45 | #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */ | |
43ff2122 | 46 | #define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */ |
1d5ae5df CH |
47 | |
48 | /* I/O hints for the BIO layer */ | |
49 | #define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */ | |
50 | #define XBF_FUA (1 << 11)/* force cache write through mode */ | |
51 | #define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */ | |
1da177e4 | 52 | |
807cbbdb | 53 | /* flags used only as arguments to access routines */ |
1d5ae5df | 54 | #define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */ |
611c9946 | 55 | #define XBF_UNMAPPED (1 << 17)/* do not map the buffer */ |
1da177e4 | 56 | |
807cbbdb | 57 | /* flags used only internally */ |
1d5ae5df CH |
58 | #define _XBF_PAGES (1 << 20)/* backed by refcounted pages */ |
59 | #define _XBF_KMEM (1 << 21)/* backed by heap memory */ | |
43ff2122 | 60 | #define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */ |
cbb7baab | 61 | #define _XBF_COMPOUND (1 << 23)/* compound buffer */ |
6ab455ee | 62 | |
807cbbdb | 63 | typedef unsigned int xfs_buf_flags_t; |
1da177e4 | 64 | |
0b1b213f CH |
65 | #define XFS_BUF_FLAGS \ |
66 | { XBF_READ, "READ" }, \ | |
67 | { XBF_WRITE, "WRITE" }, \ | |
1d5ae5df | 68 | { XBF_READ_AHEAD, "READ_AHEAD" }, \ |
0b1b213f CH |
69 | { XBF_ASYNC, "ASYNC" }, \ |
70 | { XBF_DONE, "DONE" }, \ | |
0b1b213f | 71 | { XBF_STALE, "STALE" }, \ |
1d5ae5df CH |
72 | { XBF_SYNCIO, "SYNCIO" }, \ |
73 | { XBF_FUA, "FUA" }, \ | |
74 | { XBF_FLUSH, "FLUSH" }, \ | |
a8acad70 | 75 | { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\ |
611c9946 | 76 | { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\ |
0b1b213f | 77 | { _XBF_PAGES, "PAGES" }, \ |
0e6e847f | 78 | { _XBF_KMEM, "KMEM" }, \ |
cbb7baab DC |
79 | { _XBF_DELWRI_Q, "DELWRI_Q" }, \ |
80 | { _XBF_COMPOUND, "COMPOUND" } | |
0b1b213f | 81 | |
1da177e4 | 82 | typedef struct xfs_buftarg { |
ce8e922c NS |
83 | dev_t bt_dev; |
84 | struct block_device *bt_bdev; | |
0e6e847f | 85 | struct backing_dev_info *bt_bdi; |
ebad861b | 86 | struct xfs_mount *bt_mount; |
ce8e922c NS |
87 | unsigned int bt_bsize; |
88 | unsigned int bt_sshift; | |
89 | size_t bt_smask; | |
90 | ||
ff57ab21 DC |
91 | /* LRU control structures */ |
92 | struct shrinker bt_shrinker; | |
430cbeb8 DC |
93 | struct list_head bt_lru; |
94 | spinlock_t bt_lru_lock; | |
95 | unsigned int bt_lru_nr; | |
1da177e4 LT |
96 | } xfs_buftarg_t; |
97 | ||
1da177e4 | 98 | struct xfs_buf; |
ce8e922c | 99 | typedef void (*xfs_buf_iodone_t)(struct xfs_buf *); |
1da177e4 | 100 | |
ce8e922c | 101 | #define XB_PAGES 2 |
1da177e4 | 102 | |
cbb7baab DC |
103 | struct xfs_buf_map { |
104 | xfs_daddr_t bm_bn; /* block number for I/O */ | |
105 | int bm_len; /* size of I/O */ | |
106 | }; | |
107 | ||
1da177e4 | 108 | typedef struct xfs_buf { |
50f59e8e DC |
109 | /* |
110 | * first cacheline holds all the fields needed for an uncontended cache | |
111 | * hit to be fully processed. The semaphore straddles the cacheline | |
112 | * boundary, but the counter and lock sits on the first cacheline, | |
113 | * which is the only bit that is touched if we hit the semaphore | |
114 | * fast-path on locking. | |
115 | */ | |
116 | struct rb_node b_rbnode; /* rbtree node */ | |
cbb7baab | 117 | xfs_daddr_t b_bn; /* block number of buffer */ |
4e94b71b | 118 | int b_length; /* size of buffer in BBs */ |
50f59e8e | 119 | atomic_t b_hold; /* reference count */ |
430cbeb8 | 120 | atomic_t b_lru_ref; /* lru reclaim ref count */ |
50f59e8e | 121 | xfs_buf_flags_t b_flags; /* status flags */ |
ce8e922c | 122 | struct semaphore b_sema; /* semaphore for lockables */ |
50f59e8e | 123 | |
430cbeb8 | 124 | struct list_head b_lru; /* lru list */ |
ce8e922c NS |
125 | wait_queue_head_t b_waiters; /* unpin waiters */ |
126 | struct list_head b_list; | |
74f75a0c | 127 | struct xfs_perag *b_pag; /* contains rbtree root */ |
ce8e922c | 128 | xfs_buftarg_t *b_target; /* buffer target (device) */ |
ce8e922c NS |
129 | void *b_addr; /* virtual address of buffer */ |
130 | struct work_struct b_iodone_work; | |
ce8e922c | 131 | xfs_buf_iodone_t b_iodone; /* I/O completion function */ |
b4dd330b | 132 | struct completion b_iowait; /* queue for I/O waiters */ |
ce8e922c | 133 | void *b_fspriv; |
bf9d9013 | 134 | struct xfs_trans *b_transp; |
ce8e922c NS |
135 | struct page **b_pages; /* array of page pointers */ |
136 | struct page *b_page_array[XB_PAGES]; /* inline pages */ | |
cbb7baab | 137 | struct xfs_buf_map b_map; /* compound buffer map */ |
aa0e8833 | 138 | int b_io_length; /* IO size in BBs */ |
50f59e8e DC |
139 | atomic_t b_pin_count; /* pin count */ |
140 | atomic_t b_io_remaining; /* #outstanding I/O requests */ | |
141 | unsigned int b_page_count; /* size of page array */ | |
142 | unsigned int b_offset; /* page offset in first page */ | |
143 | unsigned short b_error; /* error code on I/O */ | |
cbb7baab | 144 | |
ce8e922c NS |
145 | #ifdef XFS_BUF_LOCK_TRACKING |
146 | int b_last_holder; | |
1da177e4 LT |
147 | #endif |
148 | } xfs_buf_t; | |
149 | ||
150 | ||
151 | /* Finding and Reading Buffers */ | |
e70b73f8 DC |
152 | struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target, xfs_daddr_t blkno, |
153 | size_t numblks, xfs_buf_flags_t flags, | |
154 | struct xfs_buf *new_bp); | |
1da177e4 | 155 | #define xfs_incore(buftarg,blkno,len,lockit) \ |
ce8e922c | 156 | _xfs_buf_find(buftarg, blkno ,len, lockit, NULL) |
1da177e4 | 157 | |
e70b73f8 DC |
158 | struct xfs_buf *xfs_buf_get(struct xfs_buftarg *target, xfs_daddr_t blkno, |
159 | size_t numblks, xfs_buf_flags_t flags); | |
160 | struct xfs_buf *xfs_buf_read(struct xfs_buftarg *target, xfs_daddr_t blkno, | |
161 | size_t numblks, xfs_buf_flags_t flags); | |
162 | void xfs_buf_readahead(struct xfs_buftarg *target, xfs_daddr_t blkno, | |
163 | size_t numblks); | |
164 | ||
165 | struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks); | |
166 | struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *target, xfs_daddr_t blkno, | |
167 | size_t numblks, xfs_buf_flags_t flags); | |
168 | void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks); | |
169 | int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length); | |
170 | ||
171 | struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, | |
172 | int flags); | |
173 | struct xfs_buf *xfs_buf_read_uncached(struct xfs_buftarg *target, | |
174 | xfs_daddr_t daddr, size_t numblks, int flags); | |
175 | void xfs_buf_hold(struct xfs_buf *bp); | |
1da177e4 LT |
176 | |
177 | /* Releasing Buffers */ | |
ce8e922c NS |
178 | extern void xfs_buf_free(xfs_buf_t *); |
179 | extern void xfs_buf_rele(xfs_buf_t *); | |
1da177e4 LT |
180 | |
181 | /* Locking and Unlocking Buffers */ | |
0c842ad4 | 182 | extern int xfs_buf_trylock(xfs_buf_t *); |
ce8e922c NS |
183 | extern void xfs_buf_lock(xfs_buf_t *); |
184 | extern void xfs_buf_unlock(xfs_buf_t *); | |
0c842ad4 CH |
185 | #define xfs_buf_islocked(bp) \ |
186 | ((bp)->b_sema.count <= 0) | |
1da177e4 LT |
187 | |
188 | /* Buffer Read and Write Routines */ | |
c2b006c1 | 189 | extern int xfs_bwrite(struct xfs_buf *bp); |
4e23471a CH |
190 | |
191 | extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *); | |
192 | extern int xfs_bdstrat_cb(struct xfs_buf *); | |
193 | ||
ce8e922c NS |
194 | extern void xfs_buf_ioend(xfs_buf_t *, int); |
195 | extern void xfs_buf_ioerror(xfs_buf_t *, int); | |
901796af | 196 | extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func); |
0e95f19a | 197 | extern void xfs_buf_iorequest(xfs_buf_t *); |
ce8e922c | 198 | extern int xfs_buf_iowait(xfs_buf_t *); |
b9c48649 | 199 | extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *, |
ce8e922c | 200 | xfs_buf_rw_t); |
1a1a3e97 CH |
201 | #define xfs_buf_zero(bp, off, len) \ |
202 | xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO) | |
ce8e922c | 203 | |
ce8e922c | 204 | static inline int xfs_buf_geterror(xfs_buf_t *bp) |
1da177e4 | 205 | { |
ce8e922c | 206 | return bp ? bp->b_error : ENOMEM; |
1da177e4 LT |
207 | } |
208 | ||
209 | /* Buffer Utility Routines */ | |
ce8e922c | 210 | extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t); |
1da177e4 | 211 | |
1da177e4 | 212 | /* Delayed Write Buffer Routines */ |
43ff2122 CH |
213 | extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); |
214 | extern int xfs_buf_delwri_submit(struct list_head *); | |
215 | extern int xfs_buf_delwri_submit_nowait(struct list_head *); | |
1da177e4 LT |
216 | |
217 | /* Buffer Daemon Setup Routines */ | |
ce8e922c NS |
218 | extern int xfs_buf_init(void); |
219 | extern void xfs_buf_terminate(void); | |
1da177e4 | 220 | |
1d5ae5df | 221 | #define XFS_BUF_ZEROFLAGS(bp) \ |
43ff2122 | 222 | ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC| \ |
1d5ae5df | 223 | XBF_SYNCIO|XBF_FUA|XBF_FLUSH)) |
ce8e922c | 224 | |
430cbeb8 | 225 | void xfs_buf_stale(struct xfs_buf *bp); |
0cadda1c CH |
226 | #define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE) |
227 | #define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE) | |
1da177e4 | 228 | |
ce8e922c NS |
229 | #define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE) |
230 | #define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE) | |
231 | #define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE) | |
232 | ||
ce8e922c NS |
233 | #define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC) |
234 | #define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC) | |
235 | #define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC) | |
236 | ||
ce8e922c NS |
237 | #define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ) |
238 | #define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ) | |
239 | #define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ) | |
240 | ||
241 | #define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE) | |
242 | #define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE) | |
243 | #define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE) | |
244 | ||
cbb7baab DC |
245 | /* |
246 | * These macros use the IO block map rather than b_bn. b_bn is now really | |
247 | * just for the buffer cache index for cached buffers. As IO does not use b_bn | |
248 | * anymore, uncached buffers do not use b_bn at all and hence must modify the IO | |
249 | * map directly. Uncached buffers are not allowed to be discontiguous, so this | |
250 | * is safe to do. | |
251 | * | |
252 | * In future, uncached buffers will pass the block number directly to the io | |
253 | * request function and hence these macros will go away at that point. | |
254 | */ | |
255 | #define XFS_BUF_ADDR(bp) ((bp)->b_map.bm_bn) | |
256 | #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_map.bm_bn = (xfs_daddr_t)(bno)) | |
ce8e922c | 257 | |
38f23232 | 258 | static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) |
821eb21d DC |
259 | { |
260 | atomic_set(&bp->b_lru_ref, lru_ref); | |
261 | } | |
ce8e922c | 262 | |
811e64c7 CS |
263 | static inline int xfs_buf_ispinned(struct xfs_buf *bp) |
264 | { | |
265 | return atomic_read(&bp->b_pin_count); | |
266 | } | |
ce8e922c | 267 | |
ce8e922c | 268 | static inline void xfs_buf_relse(xfs_buf_t *bp) |
1da177e4 | 269 | { |
bfc60177 | 270 | xfs_buf_unlock(bp); |
ce8e922c | 271 | xfs_buf_rele(bp); |
1da177e4 LT |
272 | } |
273 | ||
1da177e4 LT |
274 | /* |
275 | * Handling of buftargs. | |
276 | */ | |
ebad861b DC |
277 | extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *, |
278 | struct block_device *, int, const char *); | |
c141b292 | 279 | extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *); |
1da177e4 LT |
280 | extern void xfs_wait_buftarg(xfs_buftarg_t *); |
281 | extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int); | |
d808f617 | 282 | |
ce8e922c NS |
283 | #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) |
284 | #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) | |
285 | ||
1da177e4 | 286 | #endif /* __XFS_BUF_H__ */ |