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opnsense-src/sys/sys/buf.h
Warner Losh fbbd9655e5 Renumber copyright clause 4 
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

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/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)buf.h 8.9 (Berkeley) 3/30/95
* $FreeBSD$
*/
#ifndef _SYS_BUF_H_
#define _SYS_BUF_H_
#include <sys/bufobj.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/lockmgr.h>
struct bio;
struct buf;
struct bufobj;
struct mount;
struct vnode;
struct uio;
/*
* To avoid including <ufs/ffs/softdep.h>
*/
LIST_HEAD(workhead, worklist);
/*
* These are currently used only by the soft dependency code, hence
* are stored once in a global variable. If other subsystems wanted
* to use these hooks, a pointer to a set of bio_ops could be added
* to each buffer.
*/
extern struct bio_ops {
void (*io_start)(struct buf *);
void (*io_complete)(struct buf *);
void (*io_deallocate)(struct buf *);
int (*io_countdeps)(struct buf *, int);
} bioops;
struct vm_object;
struct vm_page;
typedef unsigned char b_xflags_t;
/*
* The buffer header describes an I/O operation in the kernel.
*
* NOTES:
* b_bufsize, b_bcount. b_bufsize is the allocation size of the
* buffer, either DEV_BSIZE or PAGE_SIZE aligned. b_bcount is the
* originally requested buffer size and can serve as a bounds check
* against EOF. For most, but not all uses, b_bcount == b_bufsize.
*
* b_dirtyoff, b_dirtyend. Buffers support piecemeal, unaligned
* ranges of dirty data that need to be written to backing store.
* The range is typically clipped at b_bcount ( not b_bufsize ).
*
* b_resid. Number of bytes remaining in I/O. After an I/O operation
* completes, b_resid is usually 0 indicating 100% success.
*
* All fields are protected by the buffer lock except those marked:
* V - Protected by owning bufobj lock
* Q - Protected by the buf queue lock
* D - Protected by an dependency implementation specific lock
*/
struct buf {
struct bufobj *b_bufobj;
long b_bcount;
void *b_caller1;
caddr_t b_data;
int b_error;
uint16_t b_iocmd; /* BIO_* bio_cmd from bio.h */
uint16_t b_ioflags; /* BIO_* bio_flags from bio.h */
off_t b_iooffset;
long b_resid;
void (*b_iodone)(struct buf *);
daddr_t b_blkno; /* Underlying physical block number. */
off_t b_offset; /* Offset into file. */
TAILQ_ENTRY(buf) b_bobufs; /* (V) Buffer's associated vnode. */
uint32_t b_vflags; /* (V) BV_* flags */
unsigned short b_qindex; /* (Q) buffer queue index */
uint32_t b_flags; /* B_* flags. */
b_xflags_t b_xflags; /* extra flags */
struct lock b_lock; /* Buffer lock */
long b_bufsize; /* Allocated buffer size. */
int b_runningbufspace; /* when I/O is running, pipelining */
int b_kvasize; /* size of kva for buffer */
int b_dirtyoff; /* Offset in buffer of dirty region. */
int b_dirtyend; /* Offset of end of dirty region. */
caddr_t b_kvabase; /* base kva for buffer */
daddr_t b_lblkno; /* Logical block number. */
struct vnode *b_vp; /* Device vnode. */
struct ucred *b_rcred; /* Read credentials reference. */
struct ucred *b_wcred; /* Write credentials reference. */
union {
TAILQ_ENTRY(buf) b_freelist; /* (Q) */
struct {
void (*b_pgiodone)(void *, vm_page_t *, int, int);
int b_pgbefore;
int b_pgafter;
};
};
union cluster_info {
TAILQ_HEAD(cluster_list_head, buf) cluster_head;
TAILQ_ENTRY(buf) cluster_entry;
} b_cluster;
struct vm_page *b_pages[btoc(MAXPHYS)];
int b_npages;
struct workhead b_dep; /* (D) List of filesystem dependencies. */
void *b_fsprivate1;
void *b_fsprivate2;
void *b_fsprivate3;
#if defined(FULL_BUF_TRACKING)
#define BUF_TRACKING_SIZE 32
#define BUF_TRACKING_ENTRY(x) ((x) & (BUF_TRACKING_SIZE - 1))
const char *b_io_tracking[BUF_TRACKING_SIZE];
uint32_t b_io_tcnt;
#elif defined(BUF_TRACKING)
const char *b_io_tracking;
#endif
};
#define b_object b_bufobj->bo_object
/*
* These flags are kept in b_flags.
*
* Notes:
*
* B_ASYNC VOP calls on bp's are usually async whether or not
* B_ASYNC is set, but some subsystems, such as NFS, like
* to know what is best for the caller so they can
* optimize the I/O.
*
* B_PAGING Indicates that bp is being used by the paging system or
* some paging system and that the bp is not linked into
* the b_vp's clean/dirty linked lists or ref counts.
* Buffer vp reassignments are illegal in this case.
*
* B_CACHE This may only be set if the buffer is entirely valid.
* The situation where B_DELWRI is set and B_CACHE is
* clear MUST be committed to disk by getblk() so
* B_DELWRI can also be cleared. See the comments for
* getblk() in kern/vfs_bio.c. If B_CACHE is clear,
* the caller is expected to clear BIO_ERROR and B_INVAL,
* set BIO_READ, and initiate an I/O.
*
* The 'entire buffer' is defined to be the range from
* 0 through b_bcount.
*
* B_MALLOC Request that the buffer be allocated from the malloc
* pool, DEV_BSIZE aligned instead of PAGE_SIZE aligned.
*
* B_CLUSTEROK This flag is typically set for B_DELWRI buffers
* by filesystems that allow clustering when the buffer
* is fully dirty and indicates that it may be clustered
* with other adjacent dirty buffers. Note the clustering
* may not be used with the stage 1 data write under NFS
* but may be used for the commit rpc portion.
*
* B_VMIO Indicates that the buffer is tied into an VM object.
* The buffer's data is always PAGE_SIZE aligned even
* if b_bufsize and b_bcount are not. ( b_bufsize is
* always at least DEV_BSIZE aligned, though ).
*
* B_DIRECT Hint that we should attempt to completely free
* the pages underlying the buffer. B_DIRECT is
* sticky until the buffer is released and typically
* only has an effect when B_RELBUF is also set.
*
*/
#define B_AGE 0x00000001 /* Move to age queue when I/O done. */
#define B_NEEDCOMMIT 0x00000002 /* Append-write in progress. */
#define B_ASYNC 0x00000004 /* Start I/O, do not wait. */
#define B_DIRECT 0x00000008 /* direct I/O flag (pls free vmio) */
#define B_DEFERRED 0x00000010 /* Skipped over for cleaning */
#define B_CACHE 0x00000020 /* Bread found us in the cache. */
#define B_VALIDSUSPWRT 0x00000040 /* Valid write during suspension. */
#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
#define B_00000100 0x00000100 /* Available flag. */
#define B_DONE 0x00000200 /* I/O completed. */
#define B_EINTR 0x00000400 /* I/O was interrupted */
#define B_NOREUSE 0x00000800 /* Contents not reused once released. */
#define B_00001000 0x00001000 /* Available flag. */
#define B_INVAL 0x00002000 /* Does not contain valid info. */
#define B_BARRIER 0x00004000 /* Write this and all preceding first. */
#define B_NOCACHE 0x00008000 /* Do not cache block after use. */
#define B_MALLOC 0x00010000 /* malloced b_data */
#define B_CLUSTEROK 0x00020000 /* Pagein op, so swap() can count it. */
#define B_00040000 0x00040000 /* Available flag. */
#define B_00080000 0x00080000 /* Available flag. */
#define B_00100000 0x00100000 /* Available flag. */
#define B_00200000 0x00200000 /* Available flag. */
#define B_RELBUF 0x00400000 /* Release VMIO buffer. */
#define B_FS_FLAG1 0x00800000 /* Available flag for FS use. */
#define B_NOCOPY 0x01000000 /* Don't copy-on-write this buf. */
#define B_INFREECNT 0x02000000 /* buf is counted in numfreebufs */
#define B_PAGING 0x04000000 /* volatile paging I/O -- bypass VMIO */
#define B_MANAGED 0x08000000 /* Managed by FS. */
#define B_RAM 0x10000000 /* Read ahead mark (flag) */
#define B_VMIO 0x20000000 /* VMIO flag */
#define B_CLUSTER 0x40000000 /* pagein op, so swap() can count it */
#define B_REMFREE 0x80000000 /* Delayed bremfree */
#define PRINT_BUF_FLAGS "\20\40remfree\37cluster\36vmio\35ram\34managed" \
"\33paging\32infreecnt\31nocopy\30b23\27relbuf\26b21\25b20" \
"\24b19\23b18\22clusterok\21malloc\20nocache\17b14\16inval" \
"\15b12\14noreuse\13eintr\12done\11b8\10delwri" \
"\7validsuspwrt\6cache\5deferred\4direct\3async\2needcommit\1age"
/*
* These flags are kept in b_xflags.
*/
#define BX_VNDIRTY 0x00000001 /* On vnode dirty list */
#define BX_VNCLEAN 0x00000002 /* On vnode clean list */
#define BX_BKGRDWRITE 0x00000010 /* Do writes in background */
#define BX_BKGRDMARKER 0x00000020 /* Mark buffer for splay tree */
#define BX_ALTDATA 0x00000040 /* Holds extended data */
#define PRINT_BUF_XFLAGS "\20\7altdata\6bkgrdmarker\5bkgrdwrite\2clean\1dirty"
#define NOOFFSET (-1LL) /* No buffer offset calculated yet */
/*
* These flags are kept in b_vflags.
*/
#define BV_SCANNED 0x00000001 /* VOP_FSYNC funcs mark written bufs */
#define BV_BKGRDINPROG 0x00000002 /* Background write in progress */
#define BV_BKGRDWAIT 0x00000004 /* Background write waiting */
#define BV_BKGRDERR 0x00000008 /* Error from background write */
#define PRINT_BUF_VFLAGS "\20\4bkgrderr\3bkgrdwait\2bkgrdinprog\1scanned"
#ifdef _KERNEL
/*
* Buffer locking
*/
extern const char *buf_wmesg; /* Default buffer lock message */
#define BUF_WMESG "bufwait"
#include <sys/proc.h> /* XXX for curthread */
#include <sys/mutex.h>
/*
* Initialize a lock.
*/
#define BUF_LOCKINIT(bp) \
lockinit(&(bp)->b_lock, PRIBIO + 4, buf_wmesg, 0, 0)
/*
*
* Get a lock sleeping non-interruptably until it becomes available.
*/
#define BUF_LOCK(bp, locktype, interlock) \
_lockmgr_args_rw(&(bp)->b_lock, (locktype), (interlock), \
LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, \
LOCK_FILE, LOCK_LINE)
/*
* Get a lock sleeping with specified interruptably and timeout.
*/
#define BUF_TIMELOCK(bp, locktype, interlock, wmesg, catch, timo) \
_lockmgr_args_rw(&(bp)->b_lock, (locktype) | LK_TIMELOCK, \
(interlock), (wmesg), (PRIBIO + 4) | (catch), (timo), \
LOCK_FILE, LOCK_LINE)
/*
* Release a lock. Only the acquiring process may free the lock unless
* it has been handed off to biodone.
*/
#define BUF_UNLOCK(bp) do { \
KASSERT(((bp)->b_flags & B_REMFREE) == 0, \
("BUF_UNLOCK %p while B_REMFREE is still set.", (bp))); \
\
(void)_lockmgr_args(&(bp)->b_lock, LK_RELEASE, NULL, \
LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, \
LOCK_FILE, LOCK_LINE); \
} while (0)
/*
* Check if a buffer lock is recursed.
*/
#define BUF_LOCKRECURSED(bp) \
lockmgr_recursed(&(bp)->b_lock)
/*
* Check if a buffer lock is currently held.
*/
#define BUF_ISLOCKED(bp) \
lockstatus(&(bp)->b_lock)
/*
* Free a buffer lock.
*/
#define BUF_LOCKFREE(bp) \
lockdestroy(&(bp)->b_lock)
/*
* Print informations on a buffer lock.
*/
#define BUF_LOCKPRINTINFO(bp) \
lockmgr_printinfo(&(bp)->b_lock)
/*
* Buffer lock assertions.
*/
#if defined(INVARIANTS) && defined(INVARIANT_SUPPORT)
#define BUF_ASSERT_LOCKED(bp) \
_lockmgr_assert(&(bp)->b_lock, KA_LOCKED, LOCK_FILE, LOCK_LINE)
#define BUF_ASSERT_SLOCKED(bp) \
_lockmgr_assert(&(bp)->b_lock, KA_SLOCKED, LOCK_FILE, LOCK_LINE)
#define BUF_ASSERT_XLOCKED(bp) \
_lockmgr_assert(&(bp)->b_lock, KA_XLOCKED, LOCK_FILE, LOCK_LINE)
#define BUF_ASSERT_UNLOCKED(bp) \
_lockmgr_assert(&(bp)->b_lock, KA_UNLOCKED, LOCK_FILE, LOCK_LINE)
#define BUF_ASSERT_HELD(bp)
#define BUF_ASSERT_UNHELD(bp)
#else
#define BUF_ASSERT_LOCKED(bp)
#define BUF_ASSERT_SLOCKED(bp)
#define BUF_ASSERT_XLOCKED(bp)
#define BUF_ASSERT_UNLOCKED(bp)
#define BUF_ASSERT_HELD(bp)
#define BUF_ASSERT_UNHELD(bp)
#endif
#ifdef _SYS_PROC_H_ /* Avoid #include <sys/proc.h> pollution */
/*
* When initiating asynchronous I/O, change ownership of the lock to the
* kernel. Once done, the lock may legally released by biodone. The
* original owning process can no longer acquire it recursively, but must
* wait until the I/O is completed and the lock has been freed by biodone.
*/
#define BUF_KERNPROC(bp) \
_lockmgr_disown(&(bp)->b_lock, LOCK_FILE, LOCK_LINE)
#endif
#endif /* _KERNEL */
struct buf_queue_head {
TAILQ_HEAD(buf_queue, buf) queue;
daddr_t last_pblkno;
struct buf *insert_point;
struct buf *switch_point;
};
/*
* This structure describes a clustered I/O.
*/
struct cluster_save {
long bs_bcount; /* Saved b_bcount. */
long bs_bufsize; /* Saved b_bufsize. */
int bs_nchildren; /* Number of associated buffers. */
struct buf **bs_children; /* List of associated buffers. */
};
#ifdef _KERNEL
static __inline int
bwrite(struct buf *bp)
{
KASSERT(bp->b_bufobj != NULL, ("bwrite: no bufobj bp=%p", bp));
KASSERT(bp->b_bufobj->bo_ops != NULL, ("bwrite: no bo_ops bp=%p", bp));
KASSERT(bp->b_bufobj->bo_ops->bop_write != NULL,
("bwrite: no bop_write bp=%p", bp));
return (BO_WRITE(bp->b_bufobj, bp));
}
static __inline void
bstrategy(struct buf *bp)
{
KASSERT(bp->b_bufobj != NULL, ("bstrategy: no bufobj bp=%p", bp));
KASSERT(bp->b_bufobj->bo_ops != NULL,
("bstrategy: no bo_ops bp=%p", bp));
KASSERT(bp->b_bufobj->bo_ops->bop_strategy != NULL,
("bstrategy: no bop_strategy bp=%p", bp));
BO_STRATEGY(bp->b_bufobj, bp);
}
static __inline void
buf_start(struct buf *bp)
{
if (bioops.io_start)
(*bioops.io_start)(bp);
}
static __inline void
buf_complete(struct buf *bp)
{
if (bioops.io_complete)
(*bioops.io_complete)(bp);
}
static __inline void
buf_deallocate(struct buf *bp)
{
if (bioops.io_deallocate)
(*bioops.io_deallocate)(bp);
}
static __inline int
buf_countdeps(struct buf *bp, int i)
{
if (bioops.io_countdeps)
return ((*bioops.io_countdeps)(bp, i));
else
return (0);
}
static __inline void
buf_track(struct buf *bp, const char *location)
{
#if defined(FULL_BUF_TRACKING)
bp->b_io_tracking[BUF_TRACKING_ENTRY(bp->b_io_tcnt++)] = location;
#elif defined(BUF_TRACKING)
bp->b_io_tracking = location;
#endif
}
#endif /* _KERNEL */
/*
* Zero out the buffer's data area.
*/
#define clrbuf(bp) { \
bzero((bp)->b_data, (u_int)(bp)->b_bcount); \
(bp)->b_resid = 0; \
}
/*
* Flags for getblk's last parameter.
*/
#define GB_LOCK_NOWAIT 0x0001 /* Fail if we block on a buf lock. */
#define GB_NOCREAT 0x0002 /* Don't create a buf if not found. */
#define GB_NOWAIT_BD 0x0004 /* Do not wait for bufdaemon. */
#define GB_UNMAPPED 0x0008 /* Do not mmap buffer pages. */
#define GB_KVAALLOC 0x0010 /* But allocate KVA. */
#ifdef _KERNEL
extern int nbuf; /* The number of buffer headers */
extern long maxswzone; /* Max KVA for swap structures */
extern long maxbcache; /* Max KVA for buffer cache */
extern long runningbufspace;
extern long hibufspace;
extern int dirtybufthresh;
extern int bdwriteskip;
extern int dirtybufferflushes;
extern int altbufferflushes;
extern int nswbuf; /* Number of swap I/O buffer headers. */
extern int cluster_pbuf_freecnt; /* Number of pbufs for clusters */
extern int vnode_pbuf_freecnt; /* Number of pbufs for vnode pager */
extern int vnode_async_pbuf_freecnt; /* Number of pbufs for vnode pager,
asynchronous reads */
extern caddr_t unmapped_buf; /* Data address for unmapped buffers. */
static inline int
buf_mapped(struct buf *bp)
{
return (bp->b_data != unmapped_buf);
}
void runningbufwakeup(struct buf *);
void waitrunningbufspace(void);
caddr_t kern_vfs_bio_buffer_alloc(caddr_t v, long physmem_est);
void bufinit(void);
void bufshutdown(int);
void bdata2bio(struct buf *bp, struct bio *bip);
void bwillwrite(void);
int buf_dirty_count_severe(void);
void bremfree(struct buf *);
void bremfreef(struct buf *); /* XXX Force bremfree, only for nfs. */
#define bread(vp, blkno, size, cred, bpp) \
breadn_flags(vp, blkno, size, NULL, NULL, 0, cred, 0, bpp)
#define bread_gb(vp, blkno, size, cred, gbflags, bpp) \
breadn_flags(vp, blkno, size, NULL, NULL, 0, cred, \
gbflags, bpp)
#define breadn(vp, blkno, size, rablkno, rabsize, cnt, cred, bpp) \
breadn_flags(vp, blkno, size, rablkno, rabsize, cnt, cred, 0, bpp)
int breadn_flags(struct vnode *, daddr_t, int, daddr_t *, int *, int,
struct ucred *, int, struct buf **);
void breada(struct vnode *, daddr_t *, int *, int, struct ucred *);
void bdwrite(struct buf *);
void bawrite(struct buf *);
void babarrierwrite(struct buf *);
int bbarrierwrite(struct buf *);
void bdirty(struct buf *);
void bundirty(struct buf *);
void bufstrategy(struct bufobj *, struct buf *);
void brelse(struct buf *);
void bqrelse(struct buf *);
int vfs_bio_awrite(struct buf *);
void vfs_drain_busy_pages(struct buf *bp);
struct buf * getpbuf(int *);
struct buf *incore(struct bufobj *, daddr_t);
struct buf *gbincore(struct bufobj *, daddr_t);
struct buf *getblk(struct vnode *, daddr_t, int, int, int, int);
struct buf *geteblk(int, int);
int bufwait(struct buf *);
int bufwrite(struct buf *);
void bufdone(struct buf *);
void bufdone_finish(struct buf *);
void bd_speedup(void);
int cluster_read(struct vnode *, u_quad_t, daddr_t, long,
struct ucred *, long, int, int, struct buf **);
int cluster_wbuild(struct vnode *, long, daddr_t, int, int);
void cluster_write(struct vnode *, struct buf *, u_quad_t, int, int);
void vfs_bio_brelse(struct buf *bp, int ioflags);
void vfs_bio_bzero_buf(struct buf *bp, int base, int size);
void vfs_bio_clrbuf(struct buf *);
void vfs_bio_set_flags(struct buf *bp, int ioflags);
void vfs_bio_set_valid(struct buf *, int base, int size);
void vfs_busy_pages(struct buf *, int clear_modify);
void vfs_unbusy_pages(struct buf *);
int vmapbuf(struct buf *, int);
void vunmapbuf(struct buf *);
void relpbuf(struct buf *, int *);
void brelvp(struct buf *);
void bgetvp(struct vnode *, struct buf *);
void pbgetbo(struct bufobj *bo, struct buf *bp);
void pbgetvp(struct vnode *, struct buf *);
void pbrelbo(struct buf *);
void pbrelvp(struct buf *);
int allocbuf(struct buf *bp, int size);
void reassignbuf(struct buf *);
struct buf *trypbuf(int *);
void bwait(struct buf *, u_char, const char *);
void bdone(struct buf *);
typedef daddr_t (vbg_get_lblkno_t)(struct vnode *, vm_ooffset_t);
typedef int (vbg_get_blksize_t)(struct vnode *, daddr_t);
int vfs_bio_getpages(struct vnode *vp, struct vm_page **ma, int count,
int *rbehind, int *rahead, vbg_get_lblkno_t get_lblkno,
vbg_get_blksize_t get_blksize);
#endif /* _KERNEL */
#endif /* !_SYS_BUF_H_ */
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