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- shuffle members of struct buf to distinguish buffer cache only ones.

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- put b_private and b_dcookie into a union as they're never used
  simultaneously.
- note who can use b_private.
This commit is contained in:
yamt 2003-12-04 15:00:32 +00:00
parent 3ea6756a92
commit f4112c3e60
1 changed files with 25 additions and 10 deletions
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35
sys/sys/buf.h
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@ -1,4 +1,4 @@
/* $NetBSD: buf.h,v 1.64 2003/08/07 16:33:59 agc Exp $ */
/* $NetBSD: buf.h,v 1.65 2003/12/04 15:00:32 yamt Exp $ */
/*-
* Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
@ -149,13 +149,9 @@ struct bio_ops {
* The buffer header describes an I/O operation in the kernel.
*/
struct buf {
LIST_ENTRY(buf) b_hash; /* Hash chain. */
LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
TAILQ_ENTRY(buf) b_actq; /* Device driver queue when active. */
struct proc *b_proc; /* Associated proc if B_PHYS set. */
volatile long b_flags; /* B_* flags. */
struct simplelock b_interlock; /* Lock for b_flags changes */
volatile long b_flags; /* B_* flags. */
int b_error; /* Errno value. */
long b_bufsize; /* Allocated buffer size. */
long b_bcount; /* Valid bytes in buffer. */
@ -164,18 +160,37 @@ struct buf {
struct {
caddr_t b_addr; /* Memory, superblocks, indirect etc. */
} b_un;
void *b_saveaddr; /* Original b_addr for physio. */
daddr_t b_lblkno; /* Logical block number. */
daddr_t b_blkno; /* Underlying physical block number
(partition relative) */
daddr_t b_rawblkno; /* Raw underlying physical block
number (not partition relative) */
/* Function to call upon completion. */
void (*b_iodone) __P((struct buf *));
struct proc *b_proc; /* Associated proc if B_PHYS set. */
struct vnode *b_vp; /* File vnode. */
void *b_private; /* Private data for owner */
off_t b_dcookie; /* Offset cookie if dir block */
struct workhead b_dep; /* List of filesystem dependencies. */
void *b_saveaddr; /* Original b_addr for physio. */
/*
* private data for owner.
* - buffer cache buffers are owned by corresponding filesystem.
* - non-buffer cache buffers are owned by subsystem which
* allocated them. (filesystem, disk driver, etc)
*/
union {
void *bf_private;
off_t bf_dcookie; /* NFS: Offset cookie if dir block */
} b_fspriv;
#define b_private b_fspriv.bf_private
#define b_dcookie b_fspriv.bf_dcookie
/*
* buffer cache specific data
*/
LIST_ENTRY(buf) b_hash; /* Hash chain. */
LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
daddr_t b_lblkno; /* Logical block number. */
};
#define BUF_INIT(bp) \