The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/sys/buf.h

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)buf.h       8.9 (Berkeley) 3/30/95
   35  * $FreeBSD: releng/8.1/sys/sys/buf.h 199583 2009-11-20 15:27:52Z jhb $
   36  */
   37 
   38 #ifndef _SYS_BUF_H_
   39 #define _SYS_BUF_H_
   40 
   41 #include <sys/bufobj.h>
   42 #include <sys/queue.h>
   43 #include <sys/lock.h>
   44 #include <sys/lockmgr.h>
   45 
   46 struct bio;
   47 struct buf;
   48 struct bufobj;
   49 struct mount;
   50 struct vnode;
   51 struct uio;
   52 
   53 /*
   54  * To avoid including <ufs/ffs/softdep.h> 
   55  */   
   56 LIST_HEAD(workhead, worklist);
   57 /*
   58  * These are currently used only by the soft dependency code, hence
   59  * are stored once in a global variable. If other subsystems wanted
   60  * to use these hooks, a pointer to a set of bio_ops could be added
   61  * to each buffer.
   62  */
   63 extern struct bio_ops {
   64         void    (*io_start)(struct buf *);
   65         void    (*io_complete)(struct buf *);
   66         void    (*io_deallocate)(struct buf *);
   67         int     (*io_countdeps)(struct buf *, int);
   68 } bioops;
   69 
   70 struct vm_object;
   71 
   72 typedef unsigned char b_xflags_t;
   73 
   74 /*
   75  * The buffer header describes an I/O operation in the kernel.
   76  *
   77  * NOTES:
   78  *      b_bufsize, b_bcount.  b_bufsize is the allocation size of the
   79  *      buffer, either DEV_BSIZE or PAGE_SIZE aligned.  b_bcount is the
   80  *      originally requested buffer size and can serve as a bounds check
   81  *      against EOF.  For most, but not all uses, b_bcount == b_bufsize.
   82  *
   83  *      b_dirtyoff, b_dirtyend.  Buffers support piecemeal, unaligned
   84  *      ranges of dirty data that need to be written to backing store.
   85  *      The range is typically clipped at b_bcount ( not b_bufsize ).
   86  *
   87  *      b_resid.  Number of bytes remaining in I/O.  After an I/O operation
   88  *      completes, b_resid is usually 0 indicating 100% success.
   89  *
   90  *      All fields are protected by the buffer lock except those marked:
   91  *              V - Protected by owning bufobj lock
   92  *              Q - Protected by the buf queue lock
   93  *              D - Protected by an dependency implementation specific lock
   94  */
   95 struct buf {
   96         struct bufobj   *b_bufobj;
   97         long            b_bcount;
   98         void            *b_caller1;
   99         caddr_t         b_data;
  100         int             b_error;
  101         uint8_t         b_iocmd;
  102         uint8_t         b_ioflags;
  103         off_t           b_iooffset;
  104         long            b_resid;
  105         void    (*b_iodone)(struct buf *);
  106         daddr_t b_blkno;                /* Underlying physical block number. */
  107         off_t   b_offset;               /* Offset into file. */
  108         TAILQ_ENTRY(buf) b_bobufs;      /* (V) Buffer's associated vnode. */
  109         struct buf      *b_left;        /* (V) splay tree link */
  110         struct buf      *b_right;       /* (V) splay tree link */
  111         uint32_t        b_vflags;       /* (V) BV_* flags */
  112         TAILQ_ENTRY(buf) b_freelist;    /* (Q) Free list position inactive. */
  113         unsigned short b_qindex;        /* (Q) buffer queue index */
  114         uint32_t        b_flags;        /* B_* flags. */
  115         b_xflags_t b_xflags;            /* extra flags */
  116         struct lock b_lock;             /* Buffer lock */
  117         long    b_bufsize;              /* Allocated buffer size. */
  118         long    b_runningbufspace;      /* when I/O is running, pipelining */
  119         caddr_t b_kvabase;              /* base kva for buffer */
  120         int     b_kvasize;              /* size of kva for buffer */
  121         daddr_t b_lblkno;               /* Logical block number. */
  122         struct  vnode *b_vp;            /* Device vnode. */
  123         int     b_dirtyoff;             /* Offset in buffer of dirty region. */
  124         int     b_dirtyend;             /* Offset of end of dirty region. */
  125         struct  ucred *b_rcred;         /* Read credentials reference. */
  126         struct  ucred *b_wcred;         /* Write credentials reference. */
  127         void    *b_saveaddr;            /* Original b_addr for physio. */
  128         union   pager_info {
  129                 int     pg_reqpage;
  130         } b_pager;
  131         union   cluster_info {
  132                 TAILQ_HEAD(cluster_list_head, buf) cluster_head;
  133                 TAILQ_ENTRY(buf) cluster_entry;
  134         } b_cluster;
  135         struct  vm_page *b_pages[btoc(MAXPHYS)];
  136         int             b_npages;
  137         struct  workhead b_dep;         /* (D) List of filesystem dependencies. */
  138         void    *b_fsprivate1;
  139         void    *b_fsprivate2;
  140         void    *b_fsprivate3;
  141         int     b_pin_count;
  142 };
  143 
  144 #define b_object        b_bufobj->bo_object
  145 
  146 /*
  147  * These flags are kept in b_flags.
  148  *
  149  * Notes:
  150  *
  151  *      B_ASYNC         VOP calls on bp's are usually async whether or not
  152  *                      B_ASYNC is set, but some subsystems, such as NFS, like 
  153  *                      to know what is best for the caller so they can
  154  *                      optimize the I/O.
  155  *
  156  *      B_PAGING        Indicates that bp is being used by the paging system or
  157  *                      some paging system and that the bp is not linked into
  158  *                      the b_vp's clean/dirty linked lists or ref counts.
  159  *                      Buffer vp reassignments are illegal in this case.
  160  *
  161  *      B_CACHE         This may only be set if the buffer is entirely valid.
  162  *                      The situation where B_DELWRI is set and B_CACHE is
  163  *                      clear MUST be committed to disk by getblk() so 
  164  *                      B_DELWRI can also be cleared.  See the comments for
  165  *                      getblk() in kern/vfs_bio.c.  If B_CACHE is clear,
  166  *                      the caller is expected to clear BIO_ERROR and B_INVAL,
  167  *                      set BIO_READ, and initiate an I/O.
  168  *
  169  *                      The 'entire buffer' is defined to be the range from
  170  *                      0 through b_bcount.
  171  *
  172  *      B_MALLOC        Request that the buffer be allocated from the malloc
  173  *                      pool, DEV_BSIZE aligned instead of PAGE_SIZE aligned.
  174  *
  175  *      B_CLUSTEROK     This flag is typically set for B_DELWRI buffers
  176  *                      by filesystems that allow clustering when the buffer
  177  *                      is fully dirty and indicates that it may be clustered
  178  *                      with other adjacent dirty buffers.  Note the clustering
  179  *                      may not be used with the stage 1 data write under NFS
  180  *                      but may be used for the commit rpc portion.
  181  *
  182  *      B_VMIO          Indicates that the buffer is tied into an VM object.
  183  *                      The buffer's data is always PAGE_SIZE aligned even
  184  *                      if b_bufsize and b_bcount are not.  ( b_bufsize is 
  185  *                      always at least DEV_BSIZE aligned, though ).
  186  *
  187  *      B_DIRECT        Hint that we should attempt to completely free
  188  *                      the pages underlying the buffer.  B_DIRECT is
  189  *                      sticky until the buffer is released and typically
  190  *                      only has an effect when B_RELBUF is also set.
  191  *
  192  */
  193 
  194 #define B_AGE           0x00000001      /* Move to age queue when I/O done. */
  195 #define B_NEEDCOMMIT    0x00000002      /* Append-write in progress. */
  196 #define B_ASYNC         0x00000004      /* Start I/O, do not wait. */
  197 #define B_DIRECT        0x00000008      /* direct I/O flag (pls free vmio) */
  198 #define B_DEFERRED      0x00000010      /* Skipped over for cleaning */
  199 #define B_CACHE         0x00000020      /* Bread found us in the cache. */
  200 #define B_VALIDSUSPWRT  0x00000040      /* Valid write during suspension. */
  201 #define B_DELWRI        0x00000080      /* Delay I/O until buffer reused. */
  202 #define B_PERSISTENT    0x00000100      /* Perm. ref'ed while EXT2FS mounted. */
  203 #define B_DONE          0x00000200      /* I/O completed. */
  204 #define B_EINTR         0x00000400      /* I/O was interrupted */
  205 #define B_00000800      0x00000800      /* Available flag. */
  206 #define B_00001000      0x00001000      /* Available flag. */
  207 #define B_INVAL         0x00002000      /* Does not contain valid info. */
  208 #define B_00004000      0x00004000      /* Available flag. */
  209 #define B_NOCACHE       0x00008000      /* Do not cache block after use. */
  210 #define B_MALLOC        0x00010000      /* malloced b_data */
  211 #define B_CLUSTEROK     0x00020000      /* Pagein op, so swap() can count it. */
  212 #define B_000400000     0x00040000      /* Available flag. */
  213 #define B_000800000     0x00080000      /* Available flag. */
  214 #define B_00100000      0x00100000      /* Available flag. */
  215 #define B_DIRTY         0x00200000      /* Needs writing later (in EXT2FS). */
  216 #define B_RELBUF        0x00400000      /* Release VMIO buffer. */
  217 #define B_00800000      0x00800000      /* Available flag. */
  218 #define B_01000000      0x01000000      /* Available flag. */
  219 #define B_NEEDSGIANT    0x02000000      /* Buffer's vnode needs giant. */
  220 #define B_PAGING        0x04000000      /* volatile paging I/O -- bypass VMIO */
  221 #define B_MANAGED       0x08000000      /* Managed by FS. */
  222 #define B_RAM           0x10000000      /* Read ahead mark (flag) */
  223 #define B_VMIO          0x20000000      /* VMIO flag */
  224 #define B_CLUSTER       0x40000000      /* pagein op, so swap() can count it */
  225 #define B_REMFREE       0x80000000      /* Delayed bremfree */
  226 
  227 #define PRINT_BUF_FLAGS "\2\40remfree\37cluster\36vmio\35ram\34b27" \
  228         "\33paging\32b25\31b24\30b23\27relbuf\26dirty\25b20" \
  229         "\24b19\23b18\22clusterok\21malloc\20nocache\17b14\16inval" \
  230         "\15b12\14b11\13eintr\12done\11persist\10delwri\7validsuspwrt" \
  231         "\6cache\5deferred\4direct\3async\2needcommit\1age"
  232 
  233 /*
  234  * These flags are kept in b_xflags.
  235  */
  236 #define BX_VNDIRTY      0x00000001      /* On vnode dirty list */
  237 #define BX_VNCLEAN      0x00000002      /* On vnode clean list */
  238 #define BX_BKGRDWRITE   0x00000010      /* Do writes in background */
  239 #define BX_BKGRDMARKER  0x00000020      /* Mark buffer for splay tree */
  240 #define BX_ALTDATA      0x00000040      /* Holds extended data */
  241 
  242 #define NOOFFSET        (-1LL)          /* No buffer offset calculated yet */
  243 
  244 /*
  245  * These flags are kept in b_vflags.
  246  */
  247 #define BV_SCANNED      0x00000001      /* VOP_FSYNC funcs mark written bufs */
  248 #define BV_BKGRDINPROG  0x00000002      /* Background write in progress */
  249 #define BV_BKGRDWAIT    0x00000004      /* Background write waiting */
  250 
  251 #ifdef _KERNEL
  252 /*
  253  * Buffer locking
  254  */
  255 extern const char *buf_wmesg;           /* Default buffer lock message */
  256 #define BUF_WMESG "bufwait"
  257 #include <sys/proc.h>                   /* XXX for curthread */
  258 #include <sys/mutex.h>
  259 
  260 /*
  261  * Initialize a lock.
  262  */
  263 #define BUF_LOCKINIT(bp)                                                \
  264         lockinit(&(bp)->b_lock, PRIBIO + 4, buf_wmesg, 0, 0)
  265 /*
  266  *
  267  * Get a lock sleeping non-interruptably until it becomes available.
  268  */
  269 #define BUF_LOCK(bp, locktype, interlock)                               \
  270         _lockmgr_args(&(bp)->b_lock, (locktype), (interlock),           \
  271             LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT,         \
  272             LOCK_FILE, LOCK_LINE)
  273 
  274 /*
  275  * Get a lock sleeping with specified interruptably and timeout.
  276  */
  277 #define BUF_TIMELOCK(bp, locktype, interlock, wmesg, catch, timo)       \
  278         _lockmgr_args(&(bp)->b_lock, (locktype) | LK_TIMELOCK,          \
  279             (interlock), (wmesg), (PRIBIO + 4) | (catch), (timo),       \
  280             LOCK_FILE, LOCK_LINE)
  281 
  282 /*
  283  * Release a lock. Only the acquiring process may free the lock unless
  284  * it has been handed off to biodone.
  285  */
  286 #define BUF_UNLOCK(bp) do {                                             \
  287         KASSERT(((bp)->b_flags & B_REMFREE) == 0,                       \
  288             ("BUF_UNLOCK %p while B_REMFREE is still set.", (bp)));     \
  289                                                                         \
  290         (void)_lockmgr_args(&(bp)->b_lock, LK_RELEASE, NULL,            \
  291             LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT,         \
  292             LOCK_FILE, LOCK_LINE);                                      \
  293 } while (0)
  294 
  295 /*
  296  * Check if a buffer lock is recursed.
  297  */
  298 #define BUF_LOCKRECURSED(bp)                                            \
  299         lockmgr_recursed(&(bp)->b_lock)
  300 
  301 /*
  302  * Check if a buffer lock is currently held.
  303  */
  304 #define BUF_ISLOCKED(bp)                                                \
  305         lockstatus(&(bp)->b_lock)
  306 /*
  307  * Free a buffer lock.
  308  */
  309 #define BUF_LOCKFREE(bp)                                                \
  310         lockdestroy(&(bp)->b_lock)
  311 
  312 /*
  313  * Buffer lock assertions.
  314  */
  315 #if defined(INVARIANTS) && defined(INVARIANT_SUPPORT)
  316 #define BUF_ASSERT_LOCKED(bp)                                           \
  317         _lockmgr_assert(&(bp)->b_lock, KA_LOCKED, LOCK_FILE, LOCK_LINE)
  318 #define BUF_ASSERT_SLOCKED(bp)                                          \
  319         _lockmgr_assert(&(bp)->b_lock, KA_SLOCKED, LOCK_FILE, LOCK_LINE)
  320 #define BUF_ASSERT_XLOCKED(bp)                                          \
  321         _lockmgr_assert(&(bp)->b_lock, KA_XLOCKED, LOCK_FILE, LOCK_LINE)
  322 #define BUF_ASSERT_UNLOCKED(bp)                                         \
  323         _lockmgr_assert(&(bp)->b_lock, KA_UNLOCKED, LOCK_FILE, LOCK_LINE)
  324 #define BUF_ASSERT_HELD(bp)
  325 #define BUF_ASSERT_UNHELD(bp)
  326 #else
  327 #define BUF_ASSERT_LOCKED(bp)
  328 #define BUF_ASSERT_SLOCKED(bp)
  329 #define BUF_ASSERT_XLOCKED(bp)
  330 #define BUF_ASSERT_UNLOCKED(bp)
  331 #define BUF_ASSERT_HELD(bp)
  332 #define BUF_ASSERT_UNHELD(bp)
  333 #endif
  334 
  335 #ifdef _SYS_PROC_H_     /* Avoid #include <sys/proc.h> pollution */
  336 /*
  337  * When initiating asynchronous I/O, change ownership of the lock to the
  338  * kernel. Once done, the lock may legally released by biodone. The
  339  * original owning process can no longer acquire it recursively, but must
  340  * wait until the I/O is completed and the lock has been freed by biodone.
  341  */
  342 #define BUF_KERNPROC(bp)                                                \
  343         _lockmgr_disown(&(bp)->b_lock, LOCK_FILE, LOCK_LINE)
  344 #endif
  345 
  346 /*
  347  * Find out if the lock has waiters or not.
  348  */
  349 #define BUF_LOCKWAITERS(bp)                                             \
  350         lockmgr_waiters(&(bp)->b_lock)
  351 
  352 #endif /* _KERNEL */
  353 
  354 struct buf_queue_head {
  355         TAILQ_HEAD(buf_queue, buf) queue;
  356         daddr_t last_pblkno;
  357         struct  buf *insert_point;
  358         struct  buf *switch_point;
  359 };
  360 
  361 /*
  362  * This structure describes a clustered I/O.  It is stored in the b_saveaddr
  363  * field of the buffer on which I/O is done.  At I/O completion, cluster
  364  * callback uses the structure to parcel I/O's to individual buffers, and
  365  * then free's this structure.
  366  */
  367 struct cluster_save {
  368         long    bs_bcount;              /* Saved b_bcount. */
  369         long    bs_bufsize;             /* Saved b_bufsize. */
  370         void    *bs_saveaddr;           /* Saved b_addr. */
  371         int     bs_nchildren;           /* Number of associated buffers. */
  372         struct buf **bs_children;       /* List of associated buffers. */
  373 };
  374 
  375 #ifdef _KERNEL
  376 
  377 static __inline int
  378 bwrite(struct buf *bp)
  379 {
  380 
  381         KASSERT(bp->b_bufobj != NULL, ("bwrite: no bufobj bp=%p", bp));
  382         KASSERT(bp->b_bufobj->bo_ops != NULL, ("bwrite: no bo_ops bp=%p", bp));
  383         KASSERT(bp->b_bufobj->bo_ops->bop_write != NULL,
  384             ("bwrite: no bop_write bp=%p", bp));
  385         return (BO_WRITE(bp->b_bufobj, bp));
  386 }
  387 
  388 static __inline void
  389 bstrategy(struct buf *bp)
  390 {
  391 
  392         KASSERT(bp->b_bufobj != NULL, ("bstrategy: no bufobj bp=%p", bp));
  393         KASSERT(bp->b_bufobj->bo_ops != NULL,
  394             ("bstrategy: no bo_ops bp=%p", bp));
  395         KASSERT(bp->b_bufobj->bo_ops->bop_strategy != NULL,
  396             ("bstrategy: no bop_strategy bp=%p", bp));
  397         BO_STRATEGY(bp->b_bufobj, bp);
  398 }
  399 
  400 static __inline void
  401 buf_start(struct buf *bp)
  402 {
  403         if (bioops.io_start)
  404                 (*bioops.io_start)(bp);
  405 }
  406 
  407 static __inline void
  408 buf_complete(struct buf *bp)
  409 {
  410         if (bioops.io_complete)
  411                 (*bioops.io_complete)(bp);
  412 }
  413 
  414 static __inline void
  415 buf_deallocate(struct buf *bp)
  416 {
  417         if (bioops.io_deallocate)
  418                 (*bioops.io_deallocate)(bp);
  419         BUF_LOCKFREE(bp);
  420 }
  421 
  422 static __inline int
  423 buf_countdeps(struct buf *bp, int i)
  424 {
  425         if (bioops.io_countdeps)
  426                 return ((*bioops.io_countdeps)(bp, i));
  427         else
  428                 return (0);
  429 }
  430 
  431 #endif /* _KERNEL */
  432 
  433 /*
  434  * Zero out the buffer's data area.
  435  */
  436 #define clrbuf(bp) {                                                    \
  437         bzero((bp)->b_data, (u_int)(bp)->b_bcount);                     \
  438         (bp)->b_resid = 0;                                              \
  439 }
  440 
  441 /*
  442  * Flags for getblk's last parameter.
  443  */
  444 #define GB_LOCK_NOWAIT  0x0001          /* Fail if we block on a buf lock. */
  445 #define GB_NOCREAT      0x0002          /* Don't create a buf if not found. */
  446 #define GB_NOWAIT_BD    0x0004          /* Do not wait for bufdaemon */
  447 
  448 #ifdef _KERNEL
  449 extern int      nbuf;                   /* The number of buffer headers */
  450 extern long     maxswzone;              /* Max KVA for swap structures */
  451 extern long     maxbcache;              /* Max KVA for buffer cache */
  452 extern long     runningbufspace;
  453 extern long     hibufspace;
  454 extern int      dirtybufthresh;
  455 extern int      bdwriteskip;
  456 extern int      dirtybufferflushes;
  457 extern int      altbufferflushes;
  458 extern int      buf_maxio;              /* nominal maximum I/O for buffer */
  459 extern struct   buf *buf;               /* The buffer headers. */
  460 extern char     *buffers;               /* The buffer contents. */
  461 extern int      bufpages;               /* Number of memory pages in the buffer pool. */
  462 extern struct   buf *swbuf;             /* Swap I/O buffer headers. */
  463 extern int      nswbuf;                 /* Number of swap I/O buffer headers. */
  464 extern int      cluster_pbuf_freecnt;   /* Number of pbufs for clusters */
  465 extern int      vnode_pbuf_freecnt;     /* Number of pbufs for vnode pager */
  466 
  467 void    runningbufwakeup(struct buf *);
  468 void    waitrunningbufspace(void);
  469 caddr_t kern_vfs_bio_buffer_alloc(caddr_t v, long physmem_est);
  470 void    bufinit(void);
  471 void    bwillwrite(void);
  472 int     buf_dirty_count_severe(void);
  473 void    bremfree(struct buf *);
  474 void    bremfreef(struct buf *);        /* XXX Force bremfree, only for nfs. */
  475 int     bread(struct vnode *, daddr_t, int, struct ucred *, struct buf **);
  476 void    breada(struct vnode *, daddr_t *, int *, int, struct ucred *);
  477 int     breadn(struct vnode *, daddr_t, int, daddr_t *, int *, int,
  478             struct ucred *, struct buf **);
  479 void    bdwrite(struct buf *);
  480 void    bawrite(struct buf *);
  481 void    bdirty(struct buf *);
  482 void    bundirty(struct buf *);
  483 void    bufstrategy(struct bufobj *, struct buf *);
  484 void    brelse(struct buf *);
  485 void    bqrelse(struct buf *);
  486 int     vfs_bio_awrite(struct buf *);
  487 struct buf *     getpbuf(int *);
  488 struct buf *incore(struct bufobj *, daddr_t);
  489 struct buf *gbincore(struct bufobj *, daddr_t);
  490 struct buf *getblk(struct vnode *, daddr_t, int, int, int, int);
  491 struct buf *geteblk(int, int);
  492 int     bufwait(struct buf *);
  493 int     bufwrite(struct buf *);
  494 void    bufdone(struct buf *);
  495 void    bufdone_finish(struct buf *);
  496 
  497 int     cluster_read(struct vnode *, u_quad_t, daddr_t, long,
  498             struct ucred *, long, int, struct buf **);
  499 int     cluster_wbuild(struct vnode *, long, daddr_t, int);
  500 void    cluster_write(struct vnode *, struct buf *, u_quad_t, int);
  501 void    vfs_bio_set_valid(struct buf *, int base, int size);
  502 void    vfs_bio_clrbuf(struct buf *);
  503 void    vfs_busy_pages(struct buf *, int clear_modify);
  504 void    vfs_unbusy_pages(struct buf *);
  505 int     vmapbuf(struct buf *);
  506 void    vunmapbuf(struct buf *);
  507 void    relpbuf(struct buf *, int *);
  508 void    brelvp(struct buf *);
  509 void    bgetvp(struct vnode *, struct buf *);
  510 void    pbgetbo(struct bufobj *bo, struct buf *bp);
  511 void    pbgetvp(struct vnode *, struct buf *);
  512 void    pbrelbo(struct buf *);
  513 void    pbrelvp(struct buf *);
  514 int     allocbuf(struct buf *bp, int size);
  515 void    reassignbuf(struct buf *);
  516 struct  buf *trypbuf(int *);
  517 void    bwait(struct buf *, u_char, const char *);
  518 void    bdone(struct buf *);
  519 void    bpin(struct buf *);
  520 void    bunpin(struct buf *);
  521 void    bunpin_wait(struct buf *);
  522 
  523 #endif /* _KERNEL */
  524 
  525 #endif /* !_SYS_BUF_H_ */

Cache object: dfd160f994f98fc4c2ae3d8b027b8b69


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.