fs/xfs/linux-2.6/xfs_buf.h

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   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
   7  * published by the Free Software Foundation.
   8  *
   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.
  13  *
  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
  17  */
  18 #ifndef __XFS_BUF_H__
  19 #define __XFS_BUF_H__
  20
  21 #include <linux/list.h>
  22 #include <linux/types.h>
  23 #include <linux/spinlock.h>
  24 #include <asm/system.h>
  25 #include <linux/mm.h>
  26 #include <linux/fs.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/uio.h>
  29
  30 /*
  31  *      Base types
  32  */
  33
  34 #define XFS_BUF_DADDR_NULL      ((xfs_daddr_t) (-1LL))
  35
  36 #define xfs_buf_ctob(pp)        ((pp) * PAGE_CACHE_SIZE)
  37 #define xfs_buf_btoc(dd)        (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
  38 #define xfs_buf_btoct(dd)       ((dd) >> PAGE_CACHE_SHIFT)
  39 #define xfs_buf_poff(aa)        ((aa) & ~PAGE_CACHE_MASK)
  40
  41 typedef enum {
  42         XBRW_READ = 1,                  /* transfer into target memory */
  43         XBRW_WRITE = 2,                 /* transfer from target memory */
  44         XBRW_ZERO = 3,                  /* Zero target memory */
  45 } xfs_buf_rw_t;
  46
  47 typedef enum {
  48         XBF_READ = (1 << 0),    /* buffer intended for reading from device */
  49         XBF_WRITE = (1 << 1),   /* buffer intended for writing to device   */
  50         XBF_MAPPED = (1 << 2),  /* buffer mapped (b_addr valid)            */
  51         XBF_ASYNC = (1 << 4),   /* initiator will not wait for completion  */
  52         XBF_DONE = (1 << 5),    /* all pages in the buffer uptodate        */
  53         XBF_DELWRI = (1 << 6),  /* buffer has dirty pages                  */
  54         XBF_STALE = (1 << 7),   /* buffer has been staled, do not find it  */
  55         XBF_FS_MANAGED = (1 << 8),  /* filesystem controls freeing memory  */
  56         XBF_ORDERED = (1 << 11),    /* use ordered writes                  */
  57         XBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead             */
  58
  59         /* flags used only as arguments to access routines */
  60         XBF_LOCK = (1 << 14),       /* lock requested                      */
  61         XBF_TRYLOCK = (1 << 15),    /* lock requested, but do not wait     */
  62         XBF_DONT_BLOCK = (1 << 16), /* do not block in current thread      */
  63
  64         /* flags used only internally */
  65         _XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache                 */
  66         _XBF_PAGES = (1 << 18),     /* backed by refcounted pages          */
  67         _XBF_RUN_QUEUES = (1 << 19),/* run block device task queue         */
  68         _XBF_DELWRI_Q = (1 << 21),   /* buffer on delwri queue             */
  69
  70         /*
  71          * Special flag for supporting metadata blocks smaller than a FSB.
  72          *
  73          * In this case we can have multiple xfs_buf_t on a single page and
  74          * need to lock out concurrent xfs_buf_t readers as they only
  75          * serialise access to the buffer.
  76          *
  77          * If the FSB size >= PAGE_CACHE_SIZE case, we have no serialisation
  78          * between reads of the page. Hence we can have one thread read the
  79          * page and modify it, but then race with another thread that thinks
  80          * the page is not up-to-date and hence reads it again.
  81          *
  82          * The result is that the first modifcation to the page is lost.
  83          * This sort of AGF/AGI reading race can happen when unlinking inodes
  84          * that require truncation and results in the AGI unlinked list
  85          * modifications being lost.
  86          */
  87         _XBF_PAGE_LOCKED = (1 << 22),
  88
  89         /*
  90          * If we try a barrier write, but it fails we have to communicate
  91          * this to the upper layers.  Unfortunately b_error gets overwritten
  92          * when the buffer is re-issued so we have to add another flag to
  93          * keep this information.
  94          */
  95         _XFS_BARRIER_FAILED = (1 << 23),
  96 } xfs_buf_flags_t;
  97
  98 #define XFS_BUF_FLAGS \
  99         { XBF_READ,             "READ" }, \
 100         { XBF_WRITE,            "WRITE" }, \
 101         { XBF_MAPPED,           "MAPPED" }, \
 102         { XBF_ASYNC,            "ASYNC" }, \
 103         { XBF_DONE,             "DONE" }, \
 104         { XBF_DELWRI,           "DELWRI" }, \
 105         { XBF_STALE,            "STALE" }, \
 106         { XBF_FS_MANAGED,       "FS_MANAGED" }, \
 107         { XBF_ORDERED,          "ORDERED" }, \
 108         { XBF_READ_AHEAD,       "READ_AHEAD" }, \
 109         { XBF_LOCK,             "LOCK" },       /* should never be set */\
 110         { XBF_TRYLOCK,          "TRYLOCK" },    /* ditto */\
 111         { XBF_DONT_BLOCK,       "DONT_BLOCK" }, /* ditto */\
 112         { _XBF_PAGE_CACHE,      "PAGE_CACHE" }, \
 113         { _XBF_PAGES,           "PAGES" }, \
 114         { _XBF_RUN_QUEUES,      "RUN_QUEUES" }, \
 115         { _XBF_DELWRI_Q,        "DELWRI_Q" }, \
 116         { _XBF_PAGE_LOCKED,     "PAGE_LOCKED" }, \
 117         { _XFS_BARRIER_FAILED,  "BARRIER_FAILED" }
 118
 119
 120 typedef enum {
 121         XBT_FORCE_SLEEP = 0,
 122         XBT_FORCE_FLUSH = 1,
 123 } xfs_buftarg_flags_t;
 124
 125 typedef struct xfs_bufhash {
 126         struct list_head        bh_list;
 127         spinlock_t              bh_lock;
 128 } xfs_bufhash_t;
 129
 130 typedef struct xfs_buftarg {
 131         dev_t                   bt_dev;
 132         struct block_device     *bt_bdev;
 133         struct address_space    *bt_mapping;
 134         unsigned int            bt_bsize;
 135         unsigned int            bt_sshift;
 136         size_t                  bt_smask;
 137
 138         /* per device buffer hash table */
 139         uint                    bt_hashmask;
 140         uint                    bt_hashshift;
 141         xfs_bufhash_t           *bt_hash;
 142
 143         /* per device delwri queue */
 144         struct task_struct      *bt_task;
 145         struct list_head        bt_list;
 146         struct list_head        bt_delwrite_queue;
 147         spinlock_t              bt_delwrite_lock;
 148         unsigned long           bt_flags;
 149 } xfs_buftarg_t;
 150
 151 /*
 152  *      xfs_buf_t:  Buffer structure for pagecache-based buffers
 153  *
 154  * This buffer structure is used by the pagecache buffer management routines
 155  * to refer to an assembly of pages forming a logical buffer.
 156  *
 157  * The buffer structure is used on a temporary basis only, and discarded when
 158  * released.  The real data storage is recorded in the pagecache. Buffers are
 159  * hashed to the block device on which the file system resides.
 160  */
 161
 162 struct xfs_buf;
 163 typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
 164 typedef void (*xfs_buf_relse_t)(struct xfs_buf *);
 165 typedef int (*xfs_buf_bdstrat_t)(struct xfs_buf *);
 166
 167 #define XB_PAGES        2
 168
 169 typedef struct xfs_buf {
 170         struct semaphore        b_sema;         /* semaphore for lockables */
 171         unsigned long           b_queuetime;    /* time buffer was queued */
 172         atomic_t                b_pin_count;    /* pin count */
 173         wait_queue_head_t       b_waiters;      /* unpin waiters */
 174         struct list_head        b_list;
 175         xfs_buf_flags_t         b_flags;        /* status flags */
 176         struct list_head        b_hash_list;    /* hash table list */
 177         xfs_bufhash_t           *b_hash;        /* hash table list start */
 178         xfs_buftarg_t           *b_target;      /* buffer target (device) */
 179         atomic_t                b_hold;         /* reference count */
 180         xfs_daddr_t             b_bn;           /* block number for I/O */
 181         xfs_off_t               b_file_offset;  /* offset in file */
 182         size_t                  b_buffer_length;/* size of buffer in bytes */
 183         size_t                  b_count_desired;/* desired transfer size */
 184         void                    *b_addr;        /* virtual address of buffer */
 185         struct work_struct      b_iodone_work;
 186         atomic_t                b_io_remaining; /* #outstanding I/O requests */
 187         xfs_buf_iodone_t        b_iodone;       /* I/O completion function */
 188         xfs_buf_relse_t         b_relse;        /* releasing function */
 189         xfs_buf_bdstrat_t       b_strat;        /* pre-write function */
 190         struct completion       b_iowait;       /* queue for I/O waiters */
 191         void                    *b_fspriv;
 192         void                    *b_fspriv2;
 193         struct xfs_mount        *b_mount;
 194         unsigned short          b_error;        /* error code on I/O */
 195         unsigned int            b_page_count;   /* size of page array */
 196         unsigned int            b_offset;       /* page offset in first page */
 197         struct page             **b_pages;      /* array of page pointers */
 198         struct page             *b_page_array[XB_PAGES]; /* inline pages */
 199 #ifdef XFS_BUF_LOCK_TRACKING
 200         int                     b_last_holder;
 201 #endif
 202 } xfs_buf_t;
 203
 204
 205 /* Finding and Reading Buffers */
 206 extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
 207                                 xfs_buf_flags_t, xfs_buf_t *);
 208 #define xfs_incore(buftarg,blkno,len,lockit) \
 209         _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
 210
 211 extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
 212                                 xfs_buf_flags_t);
 213 extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
 214                                 xfs_buf_flags_t);
 215
 216 extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_t *);
 217 extern xfs_buf_t *xfs_buf_get_noaddr(size_t, xfs_buftarg_t *);
 218 extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
 219 extern void xfs_buf_hold(xfs_buf_t *);
 220 extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t,
 221                                 xfs_buf_flags_t);
 222
 223 /* Releasing Buffers */
 224 extern void xfs_buf_free(xfs_buf_t *);
 225 extern void xfs_buf_rele(xfs_buf_t *);
 226
 227 /* Locking and Unlocking Buffers */
 228 extern int xfs_buf_cond_lock(xfs_buf_t *);
 229 extern int xfs_buf_lock_value(xfs_buf_t *);
 230 extern void xfs_buf_lock(xfs_buf_t *);
 231 extern void xfs_buf_unlock(xfs_buf_t *);
 232
 233 /* Buffer Read and Write Routines */
 234 extern int xfs_bawrite(void *mp, xfs_buf_t *bp);
 235 extern void xfs_bdwrite(void *mp, xfs_buf_t *bp);
 236 extern void xfs_buf_ioend(xfs_buf_t *,  int);
 237 extern void xfs_buf_ioerror(xfs_buf_t *, int);
 238 extern int xfs_buf_iorequest(xfs_buf_t *);
 239 extern int xfs_buf_iowait(xfs_buf_t *);
 240 extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, xfs_caddr_t,
 241                                 xfs_buf_rw_t);
 242
 243 static inline int xfs_buf_iostrategy(xfs_buf_t *bp)
 244 {
 245         return bp->b_strat ? bp->b_strat(bp) : xfs_buf_iorequest(bp);
 246 }
 247
 248 static inline int xfs_buf_geterror(xfs_buf_t *bp)
 249 {
 250         return bp ? bp->b_error : ENOMEM;
 251 }
 252
 253 /* Buffer Utility Routines */
 254 extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
 255
 256 /* Pinning Buffer Storage in Memory */
 257 extern void xfs_buf_pin(xfs_buf_t *);
 258 extern void xfs_buf_unpin(xfs_buf_t *);
 259 extern int xfs_buf_ispin(xfs_buf_t *);
 260
 261 /* Delayed Write Buffer Routines */
 262 extern void xfs_buf_delwri_dequeue(xfs_buf_t *);
 263
 264 /* Buffer Daemon Setup Routines */
 265 extern int xfs_buf_init(void);
 266 extern void xfs_buf_terminate(void);
 267
 268 #define xfs_buf_target_name(target)     \
 269         ({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; })
 270
 271
 272 #define XFS_B_ASYNC             XBF_ASYNC
 273 #define XFS_B_DELWRI            XBF_DELWRI
 274 #define XFS_B_READ              XBF_READ
 275 #define XFS_B_WRITE             XBF_WRITE
 276 #define XFS_B_STALE             XBF_STALE
 277
 278 #define XFS_BUF_TRYLOCK         XBF_TRYLOCK
 279 #define XFS_INCORE_TRYLOCK      XBF_TRYLOCK
 280 #define XFS_BUF_LOCK            XBF_LOCK
 281 #define XFS_BUF_MAPPED          XBF_MAPPED
 282
 283 #define BUF_BUSY                XBF_DONT_BLOCK
 284
 285 #define XFS_BUF_BFLAGS(bp)      ((bp)->b_flags)
 286 #define XFS_BUF_ZEROFLAGS(bp)   ((bp)->b_flags &= \
 287                 ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED))
 288
 289 #define XFS_BUF_STALE(bp)       ((bp)->b_flags |= XFS_B_STALE)
 290 #define XFS_BUF_UNSTALE(bp)     ((bp)->b_flags &= ~XFS_B_STALE)
 291 #define XFS_BUF_ISSTALE(bp)     ((bp)->b_flags & XFS_B_STALE)
 292 #define XFS_BUF_SUPER_STALE(bp) do {                            \
 293                                         XFS_BUF_STALE(bp);      \
 294                                         xfs_buf_delwri_dequeue(bp);     \
 295                                         XFS_BUF_DONE(bp);       \
 296                                 } while (0)
 297
 298 #define XFS_BUF_MANAGE          XBF_FS_MANAGED
 299 #define XFS_BUF_UNMANAGE(bp)    ((bp)->b_flags &= ~XBF_FS_MANAGED)
 300
 301 #define XFS_BUF_DELAYWRITE(bp)          ((bp)->b_flags |= XBF_DELWRI)
 302 #define XFS_BUF_UNDELAYWRITE(bp)        xfs_buf_delwri_dequeue(bp)
 303 #define XFS_BUF_ISDELAYWRITE(bp)        ((bp)->b_flags & XBF_DELWRI)
 304
 305 #define XFS_BUF_ERROR(bp,no)    xfs_buf_ioerror(bp,no)
 306 #define XFS_BUF_GETERROR(bp)    xfs_buf_geterror(bp)
 307 #define XFS_BUF_ISERROR(bp)     (xfs_buf_geterror(bp) ? 1 : 0)
 308
 309 #define XFS_BUF_DONE(bp)        ((bp)->b_flags |= XBF_DONE)
 310 #define XFS_BUF_UNDONE(bp)      ((bp)->b_flags &= ~XBF_DONE)
 311 #define XFS_BUF_ISDONE(bp)      ((bp)->b_flags & XBF_DONE)
 312
 313 #define XFS_BUF_BUSY(bp)        do { } while (0)
 314 #define XFS_BUF_UNBUSY(bp)      do { } while (0)
 315 #define XFS_BUF_ISBUSY(bp)      (1)
 316
 317 #define XFS_BUF_ASYNC(bp)       ((bp)->b_flags |= XBF_ASYNC)
 318 #define XFS_BUF_UNASYNC(bp)     ((bp)->b_flags &= ~XBF_ASYNC)
 319 #define XFS_BUF_ISASYNC(bp)     ((bp)->b_flags & XBF_ASYNC)
 320
 321 #define XFS_BUF_ORDERED(bp)     ((bp)->b_flags |= XBF_ORDERED)
 322 #define XFS_BUF_UNORDERED(bp)   ((bp)->b_flags &= ~XBF_ORDERED)
 323 #define XFS_BUF_ISORDERED(bp)   ((bp)->b_flags & XBF_ORDERED)
 324
 325 #define XFS_BUF_HOLD(bp)        xfs_buf_hold(bp)
 326 #define XFS_BUF_READ(bp)        ((bp)->b_flags |= XBF_READ)
 327 #define XFS_BUF_UNREAD(bp)      ((bp)->b_flags &= ~XBF_READ)
 328 #define XFS_BUF_ISREAD(bp)      ((bp)->b_flags & XBF_READ)
 329
 330 #define XFS_BUF_WRITE(bp)       ((bp)->b_flags |= XBF_WRITE)
 331 #define XFS_BUF_UNWRITE(bp)     ((bp)->b_flags &= ~XBF_WRITE)
 332 #define XFS_BUF_ISWRITE(bp)     ((bp)->b_flags & XBF_WRITE)
 333
 334 #define XFS_BUF_IODONE_FUNC(bp)                 ((bp)->b_iodone)
 335 #define XFS_BUF_SET_IODONE_FUNC(bp, func)       ((bp)->b_iodone = (func))
 336 #define XFS_BUF_CLR_IODONE_FUNC(bp)             ((bp)->b_iodone = NULL)
 337 #define XFS_BUF_SET_BDSTRAT_FUNC(bp, func)      ((bp)->b_strat = (func))
 338 #define XFS_BUF_CLR_BDSTRAT_FUNC(bp)            ((bp)->b_strat = NULL)
 339
 340 #define XFS_BUF_FSPRIVATE(bp, type)             ((type)(bp)->b_fspriv)
 341 #define XFS_BUF_SET_FSPRIVATE(bp, val)          ((bp)->b_fspriv = (void*)(val))
 342 #define XFS_BUF_FSPRIVATE2(bp, type)            ((type)(bp)->b_fspriv2)
 343 #define XFS_BUF_SET_FSPRIVATE2(bp, val)         ((bp)->b_fspriv2 = (void*)(val))
 344 #define XFS_BUF_SET_START(bp)                   do { } while (0)
 345 #define XFS_BUF_SET_BRELSE_FUNC(bp, func)       ((bp)->b_relse = (func))
 346
 347 #define XFS_BUF_PTR(bp)                 (xfs_caddr_t)((bp)->b_addr)
 348 #define XFS_BUF_SET_PTR(bp, val, cnt)   xfs_buf_associate_memory(bp, val, cnt)
 349 #define XFS_BUF_ADDR(bp)                ((bp)->b_bn)
 350 #define XFS_BUF_SET_ADDR(bp, bno)       ((bp)->b_bn = (xfs_daddr_t)(bno))
 351 #define XFS_BUF_OFFSET(bp)              ((bp)->b_file_offset)
 352 #define XFS_BUF_SET_OFFSET(bp, off)     ((bp)->b_file_offset = (off))
 353 #define XFS_BUF_COUNT(bp)               ((bp)->b_count_desired)
 354 #define XFS_BUF_SET_COUNT(bp, cnt)      ((bp)->b_count_desired = (cnt))
 355 #define XFS_BUF_SIZE(bp)                ((bp)->b_buffer_length)
 356 #define XFS_BUF_SET_SIZE(bp, cnt)       ((bp)->b_buffer_length = (cnt))
 357
 358 #define XFS_BUF_SET_VTYPE_REF(bp, type, ref)    do { } while (0)
 359 #define XFS_BUF_SET_VTYPE(bp, type)             do { } while (0)
 360 #define XFS_BUF_SET_REF(bp, ref)                do { } while (0)
 361
 362 #define XFS_BUF_ISPINNED(bp)    xfs_buf_ispin(bp)
 363
 364 #define XFS_BUF_VALUSEMA(bp)    xfs_buf_lock_value(bp)
 365 #define XFS_BUF_CPSEMA(bp)      (xfs_buf_cond_lock(bp) == 0)
 366 #define XFS_BUF_VSEMA(bp)       xfs_buf_unlock(bp)
 367 #define XFS_BUF_PSEMA(bp,x)     xfs_buf_lock(bp)
 368 #define XFS_BUF_FINISH_IOWAIT(bp)       complete(&bp->b_iowait);
 369
 370 #define XFS_BUF_SET_TARGET(bp, target)  ((bp)->b_target = (target))
 371 #define XFS_BUF_TARGET(bp)              ((bp)->b_target)
 372 #define XFS_BUFTARG_NAME(target)        xfs_buf_target_name(target)
 373
 374 static inline void xfs_buf_relse(xfs_buf_t *bp)
 375 {
 376         if (!bp->b_relse)
 377                 xfs_buf_unlock(bp);
 378         xfs_buf_rele(bp);
 379 }
 380
 381 #define xfs_bpin(bp)            xfs_buf_pin(bp)
 382 #define xfs_bunpin(bp)          xfs_buf_unpin(bp)
 383 #define xfs_biodone(bp)         xfs_buf_ioend(bp, 0)
 384
 385 #define xfs_biomove(bp, off, len, data, rw) \
 386             xfs_buf_iomove((bp), (off), (len), (data), \
 387                 ((rw) == XFS_B_WRITE) ? XBRW_WRITE : XBRW_READ)
 388
 389 #define xfs_biozero(bp, off, len) \
 390             xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
 391
 392
 393 static inline int XFS_bwrite(xfs_buf_t *bp)
 394 {
 395         int     iowait = (bp->b_flags & XBF_ASYNC) == 0;
 396         int     error = 0;
 397
 398         if (!iowait)
 399                 bp->b_flags |= _XBF_RUN_QUEUES;
 400
 401         xfs_buf_delwri_dequeue(bp);
 402         xfs_buf_iostrategy(bp);
 403         if (iowait) {
 404                 error = xfs_buf_iowait(bp);
 405                 xfs_buf_relse(bp);
 406         }
 407         return error;
 408 }
 409
 410 #define XFS_bdstrat(bp) xfs_buf_iorequest(bp)
 411
 412 #define xfs_iowait(bp)  xfs_buf_iowait(bp)
 413
 414 #define xfs_baread(target, rablkno, ralen)  \
 415         xfs_buf_readahead((target), (rablkno), (ralen), XBF_DONT_BLOCK)
 416
 417
 418 /*
 419  *      Handling of buftargs.
 420  */
 421 extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int);
 422 extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
 423 extern void xfs_wait_buftarg(xfs_buftarg_t *);
 424 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
 425 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
 426 #ifdef CONFIG_KDB_MODULES
 427 extern struct list_head *xfs_get_buftarg_list(void);
 428 #endif
 429
 430 #define xfs_getsize_buftarg(buftarg)    block_size((buftarg)->bt_bdev)
 431 #define xfs_readonly_buftarg(buftarg)   bdev_read_only((buftarg)->bt_bdev)
 432
 433 #define xfs_binval(buftarg)             xfs_flush_buftarg(buftarg, 1)
 434 #define XFS_bflush(buftarg)             xfs_flush_buftarg(buftarg, 1)
 435
 436 #endif  /* __XFS_BUF_H__ */