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Move the buffered read/write code out of spec_{read|write} and into

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two new functions spec_buf{read|write}.

Add sysctl vfs.bdev_buffered which defaults to 1 == true.  This
sysctl can be used to experimentally turn buffered behaviour for
bdevs off.  I should not be changed while any blockdevices are
open.  Remove the misplaced sysctl vfs.enable_userblk_io.

No other changes in behaviour.
This commit is contained in:
phk 1999-10-04 11:23:10 +00:00
parent 32722204f7
commit 8b06d6a2fb
5 changed files with 428 additions and 377 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

399
sys/fs/specfs/spec_vnops.c
View File

@ -46,6 +46,7 @@
#include <sys/fcntl.h>
#include <sys/disklabel.h>
#include <sys/vmmeter.h>
#include <sys/sysctl.h>
#include <sys/tty.h>
#include <vm/vm.h>
@ -70,8 +71,10 @@ static int spec_open __P((struct vop_open_args *));
static int spec_poll __P((struct vop_poll_args *));
static int spec_print __P((struct vop_print_args *));
static int spec_read __P((struct vop_read_args *));
static int spec_bufread __P((struct vop_read_args *));
static int spec_strategy __P((struct vop_strategy_args *));
static int spec_write __P((struct vop_write_args *));
static int spec_bufwrite __P((struct vop_write_args *));
vop_t **spec_vnodeop_p;
static struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
@ -114,6 +117,8 @@ static struct vnodeopv_desc spec_vnodeop_opv_desc =
VNODEOP_SET(spec_vnodeop_opv_desc);
static int bdev_buffered = 1;
SYSCTL_INT(_vfs, OID_AUTO, bdev_buffered, CTLFLAG_RW, &bdev_buffered, 0, "");
int
spec_vnoperate(ap)
@ -159,7 +164,7 @@ spec_open(ap)
struct proc *p = ap->a_p;
struct vnode *bvp, *vp = ap->a_vp;
dev_t bdev, dev = vp->v_rdev;
int error, maxio;
int error;
struct cdevsw *dsw;
/*
@ -267,8 +272,45 @@ spec_read(ap)
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct uio *uio = ap->a_uio;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
int error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("spec_read mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_read proc");
#endif
if (uio->uio_resid == 0)
return (0);
if (vp->v_type == VCHR || (bdev_buffered == 0)) {
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_read)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
} else {
return (spec_bufread(ap));
}
}
/* Vnode op for buffered read */
/* ARGSUSED */
static int
spec_bufread(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn, nextbn;
@ -280,92 +322,67 @@ spec_read(ap)
int seqcount = ap->a_ioflag >> 16;
dev_t dev;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("spec_read mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_read proc");
#endif
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
dev = vp->v_rdev;
switch (vp->v_type) {
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
*/
case VCHR:
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_read)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
case VBLK:
if (enable_userblk_io == 0)
return (EINVAL);
if (uio->uio_offset < 0)
return (EINVAL);
dev = vp->v_rdev;
if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
(*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag * dpart.part->p_fsize;
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
if (seqcount > 1) {
nextbn = bn + bscale;
error = breadn(vp, bn, (int)bsize, &nextbn,
(int *)&bsize, 1, NOCRED, &bp);
} else {
error = bread(vp, bn, (int)bsize, NOCRED, &bp);
}
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
* Figure out how much of the buffer is valid relative
* to our offset into the buffer, which may be negative
* if we are beyond the EOF.
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
(*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag * dpart.part->p_fsize;
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
if (seqcount > 1) {
nextbn = bn + bscale;
error = breadn(vp, bn, (int)bsize, &nextbn,
(int *)&bsize, 1, NOCRED, &bp);
if (error == 0) {
n = bp->b_bcount - on;
if (n < 0) {
error = EINVAL;
} else {
error = bread(vp, bn, (int)bsize, NOCRED, &bp);
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
/*
* Figure out how much of the buffer is valid relative
* to our offset into the buffer, which may be negative
* if we are beyond the EOF.
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*/
if (error == 0) {
n = bp->b_bcount - on;
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
if (error) {
brelse(bp);
return (error);
}
n = min(n, uio->uio_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
}
if (error) {
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_read type");
}
return (error);
}
n = min(n, uio->uio_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
/* NOTREACHED */
}
@ -382,14 +399,9 @@ spec_write(ap)
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct uio *uio = ap->a_uio;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn;
int bsize, blkmask;
struct partinfo dpart;
register int n, on;
int error = 0;
#ifdef DIAGNOSTIC
@ -399,98 +411,114 @@ spec_write(ap)
panic("spec_write proc");
#endif
switch (vp->v_type) {
case VCHR:
if (vp->v_type == VCHR || (bdev_buffered == 0)) {
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_write)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
} else {
return (spec_bufwrite(ap));
}
}
case VBLK:
if (enable_userblk_io == 0)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
/* Vnode op for buffered write */
/* ARGSUSED */
static int
spec_bufwrite(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn;
int bsize, blkmask;
struct partinfo dpart;
register int n, on;
int error = 0;
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
(caddr_t)&dpart, FREAD, p) == 0) {
if (dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag *
dpart.part->p_fsize;
}
blkmask = btodb(bsize) - 1;
do {
bn = btodb(uio->uio_offset) & ~blkmask;
on = uio->uio_offset % bsize;
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
* Calculate potential request size, determine
* if we can avoid a read-before-write.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
n = min((unsigned)(bsize - on), uio->uio_resid);
if (n == bsize)
bp = getblk(vp, bn, bsize, 0, 0);
else
error = bread(vp, bn, bsize, NOCRED, &bp);
if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
(caddr_t)&dpart, FREAD, p) == 0) {
if (dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag *
dpart.part->p_fsize;
/*
* n is the amount of effective space in the buffer
* that we wish to write relative to our offset into
* the buffer. We have to truncate it to the valid
* size of the buffer relative to our offset into
* the buffer (which may end up being negative if
* we are beyond the EOF).
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*
* XXX In a newly created buffer, b_bcount == bsize
* and, being asynchronous, we have no idea of the
* EOF.
*/
if (error == 0) {
n = min(n, bp->b_bcount - on);
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
blkmask = btodb(bsize) - 1;
do {
bn = btodb(uio->uio_offset) & ~blkmask;
on = uio->uio_offset % bsize;
/*
* Calculate potential request size, determine
* if we can avoid a read-before-write.
*/
n = min((unsigned)(bsize - on), uio->uio_resid);
if (n == bsize)
bp = getblk(vp, bn, bsize, 0, 0);
else
error = bread(vp, bn, bsize, NOCRED, &bp);
/*
* n is the amount of effective space in the buffer
* that we wish to write relative to our offset into
* the buffer. We have to truncate it to the valid
* size of the buffer relative to our offset into
* the buffer (which may end up being negative if
* we are beyond the EOF).
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*
* XXX In a newly created buffer, b_bcount == bsize
* and, being asynchronous, we have no idea of the
* EOF.
*/
if (error == 0) {
n = min(n, bp->b_bcount - on);
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_write type");
}
/* NOTREACHED */
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
}
/*
@ -707,7 +735,8 @@ spec_close(ap)
struct proc *a_p;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
struct vnode *vp = ap->a_vp;
struct proc *p = ap->a_p;
dev_t dev = vp->v_rdev;
int mode, error;
@ -723,27 +752,27 @@ spec_close(ap)
* if the reference count is 2 (this last descriptor
* plus the session), release the reference from the session.
*/
if (vcount(vp) == 2 && ap->a_p &&
(vp->v_flag & VXLOCK) == 0 &&
vp == ap->a_p->p_session->s_ttyvp) {
if (vcount(vp) == 2 && p && (vp->v_flag & VXLOCK) == 0 &&
vp == p->p_session->s_ttyvp) {
vrele(vp);
ap->a_p->p_session->s_ttyvp = NULL;
p->p_session->s_ttyvp = NULL;
}
mode = S_IFCHR;
break;
case VBLK:
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
VOP_UNLOCK(vp, 0, ap->a_p);
if (error)
return (error);
if (bdev_buffered) {
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, p, 0, 0);
VOP_UNLOCK(vp, 0, p);
if (error)
return (error);
}
mode = S_IFBLK;
break;
@ -766,7 +795,7 @@ spec_close(ap)
} else if (vcount(vp) > 1) {
return (0);
}
return (devsw(dev)->d_close(dev, ap->a_fflag, mode, ap->a_p));
return (devsw(dev)->d_close(dev, ap->a_fflag, mode, p));
}
/*

3
sys/kern/vfs_export.c
View File

@ -113,9 +113,6 @@ SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad,
static int reassignbufmethod = 1;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, "");
int enable_userblk_io = 1;
SYSCTL_INT(_vfs, OID_AUTO, enable_userblk_io, CTLFLAG_RW, &enable_userblk_io, 0, "");
#ifdef ENABLE_VFS_IOOPT
int vfs_ioopt = 0;
SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");

3
sys/kern/vfs_subr.c
View File

@ -113,9 +113,6 @@ SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad,
static int reassignbufmethod = 1;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, "");
int enable_userblk_io = 1;
SYSCTL_INT(_vfs, OID_AUTO, enable_userblk_io, CTLFLAG_RW, &enable_userblk_io, 0, "");
#ifdef ENABLE_VFS_IOOPT
int vfs_ioopt = 0;
SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");

399
sys/miscfs/specfs/spec_vnops.c
View File

@ -46,6 +46,7 @@
#include <sys/fcntl.h>
#include <sys/disklabel.h>
#include <sys/vmmeter.h>
#include <sys/sysctl.h>
#include <sys/tty.h>
#include <vm/vm.h>
@ -70,8 +71,10 @@ static int spec_open __P((struct vop_open_args *));
static int spec_poll __P((struct vop_poll_args *));
static int spec_print __P((struct vop_print_args *));
static int spec_read __P((struct vop_read_args *));
static int spec_bufread __P((struct vop_read_args *));
static int spec_strategy __P((struct vop_strategy_args *));
static int spec_write __P((struct vop_write_args *));
static int spec_bufwrite __P((struct vop_write_args *));
vop_t **spec_vnodeop_p;
static struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
@ -114,6 +117,8 @@ static struct vnodeopv_desc spec_vnodeop_opv_desc =
VNODEOP_SET(spec_vnodeop_opv_desc);
static int bdev_buffered = 1;
SYSCTL_INT(_vfs, OID_AUTO, bdev_buffered, CTLFLAG_RW, &bdev_buffered, 0, "");
int
spec_vnoperate(ap)
@ -159,7 +164,7 @@ spec_open(ap)
struct proc *p = ap->a_p;
struct vnode *bvp, *vp = ap->a_vp;
dev_t bdev, dev = vp->v_rdev;
int error, maxio;
int error;
struct cdevsw *dsw;
/*
@ -267,8 +272,45 @@ spec_read(ap)
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct uio *uio = ap->a_uio;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
int error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("spec_read mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_read proc");
#endif
if (uio->uio_resid == 0)
return (0);
if (vp->v_type == VCHR || (bdev_buffered == 0)) {
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_read)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
} else {
return (spec_bufread(ap));
}
}
/* Vnode op for buffered read */
/* ARGSUSED */
static int
spec_bufread(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn, nextbn;
@ -280,92 +322,67 @@ spec_read(ap)
int seqcount = ap->a_ioflag >> 16;
dev_t dev;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("spec_read mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_read proc");
#endif
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
dev = vp->v_rdev;
switch (vp->v_type) {
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
*/
case VCHR:
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_read)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
case VBLK:
if (enable_userblk_io == 0)
return (EINVAL);
if (uio->uio_offset < 0)
return (EINVAL);
dev = vp->v_rdev;
if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
(*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag * dpart.part->p_fsize;
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
if (seqcount > 1) {
nextbn = bn + bscale;
error = breadn(vp, bn, (int)bsize, &nextbn,
(int *)&bsize, 1, NOCRED, &bp);
} else {
error = bread(vp, bn, (int)bsize, NOCRED, &bp);
}
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
* Figure out how much of the buffer is valid relative
* to our offset into the buffer, which may be negative
* if we are beyond the EOF.
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
if ((ioctl = devsw(dev)->d_ioctl) != NULL &&
(*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag * dpart.part->p_fsize;
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
if (seqcount > 1) {
nextbn = bn + bscale;
error = breadn(vp, bn, (int)bsize, &nextbn,
(int *)&bsize, 1, NOCRED, &bp);
if (error == 0) {
n = bp->b_bcount - on;
if (n < 0) {
error = EINVAL;
} else {
error = bread(vp, bn, (int)bsize, NOCRED, &bp);
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
/*
* Figure out how much of the buffer is valid relative
* to our offset into the buffer, which may be negative
* if we are beyond the EOF.
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*/
if (error == 0) {
n = bp->b_bcount - on;
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
if (error) {
brelse(bp);
return (error);
}
n = min(n, uio->uio_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
}
if (error) {
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_read type");
}
return (error);
}
n = min(n, uio->uio_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
/* NOTREACHED */
}
@ -382,14 +399,9 @@ spec_write(ap)
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct uio *uio = ap->a_uio;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn;
int bsize, blkmask;
struct partinfo dpart;
register int n, on;
int error = 0;
#ifdef DIAGNOSTIC
@ -399,98 +411,114 @@ spec_write(ap)
panic("spec_write proc");
#endif
switch (vp->v_type) {
case VCHR:
if (vp->v_type == VCHR || (bdev_buffered == 0)) {
VOP_UNLOCK(vp, 0, p);
error = (*devsw(vp->v_rdev)->d_write)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
} else {
return (spec_bufwrite(ap));
}
}
case VBLK:
if (enable_userblk_io == 0)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
/* Vnode op for buffered write */
/* ARGSUSED */
static int
spec_bufwrite(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr_t bn;
int bsize, blkmask;
struct partinfo dpart;
register int n, on;
int error = 0;
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
(caddr_t)&dpart, FREAD, p) == 0) {
if (dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag *
dpart.part->p_fsize;
}
blkmask = btodb(bsize) - 1;
do {
bn = btodb(uio->uio_offset) & ~blkmask;
on = uio->uio_offset % bsize;
/*
* Calculate block size for block device. The block size must
* be larger then the physical minimum.
* Calculate potential request size, determine
* if we can avoid a read-before-write.
*/
bsize = vp->v_rdev->si_bsize_best;
if (bsize < vp->v_rdev->si_bsize_phys)
bsize = vp->v_rdev->si_bsize_phys;
if (bsize < BLKDEV_IOSIZE)
bsize = BLKDEV_IOSIZE;
n = min((unsigned)(bsize - on), uio->uio_resid);
if (n == bsize)
bp = getblk(vp, bn, bsize, 0, 0);
else
error = bread(vp, bn, bsize, NOCRED, &bp);
if ((*devsw(vp->v_rdev)->d_ioctl)(vp->v_rdev, DIOCGPART,
(caddr_t)&dpart, FREAD, p) == 0) {
if (dpart.part->p_fstype == FS_BSDFFS &&
dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
bsize = dpart.part->p_frag *
dpart.part->p_fsize;
/*
* n is the amount of effective space in the buffer
* that we wish to write relative to our offset into
* the buffer. We have to truncate it to the valid
* size of the buffer relative to our offset into
* the buffer (which may end up being negative if
* we are beyond the EOF).
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*
* XXX In a newly created buffer, b_bcount == bsize
* and, being asynchronous, we have no idea of the
* EOF.
*/
if (error == 0) {
n = min(n, bp->b_bcount - on);
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
blkmask = btodb(bsize) - 1;
do {
bn = btodb(uio->uio_offset) & ~blkmask;
on = uio->uio_offset % bsize;
/*
* Calculate potential request size, determine
* if we can avoid a read-before-write.
*/
n = min((unsigned)(bsize - on), uio->uio_resid);
if (n == bsize)
bp = getblk(vp, bn, bsize, 0, 0);
else
error = bread(vp, bn, bsize, NOCRED, &bp);
/*
* n is the amount of effective space in the buffer
* that we wish to write relative to our offset into
* the buffer. We have to truncate it to the valid
* size of the buffer relative to our offset into
* the buffer (which may end up being negative if
* we are beyond the EOF).
*
* The valid size of the buffer is based on
* bp->b_bcount (which may have been truncated by
* dscheck or the device) minus bp->b_resid, which
* may be indicative of an I/O error if non-zero.
*
* XXX In a newly created buffer, b_bcount == bsize
* and, being asynchronous, we have no idea of the
* EOF.
*/
if (error == 0) {
n = min(n, bp->b_bcount - on);
if (n < 0) {
error = EINVAL;
} else {
n = min(n, bp->b_bcount - bp->b_resid - on);
if (n < 0)
error = EIO;
}
}
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_write type");
}
/* NOTREACHED */
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
}
/*
@ -707,7 +735,8 @@ spec_close(ap)
struct proc *a_p;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
struct vnode *vp = ap->a_vp;
struct proc *p = ap->a_p;
dev_t dev = vp->v_rdev;
int mode, error;
@ -723,27 +752,27 @@ spec_close(ap)
* if the reference count is 2 (this last descriptor
* plus the session), release the reference from the session.
*/
if (vcount(vp) == 2 && ap->a_p &&
(vp->v_flag & VXLOCK) == 0 &&
vp == ap->a_p->p_session->s_ttyvp) {
if (vcount(vp) == 2 && p && (vp->v_flag & VXLOCK) == 0 &&
vp == p->p_session->s_ttyvp) {
vrele(vp);
ap->a_p->p_session->s_ttyvp = NULL;
p->p_session->s_ttyvp = NULL;
}
mode = S_IFCHR;
break;
case VBLK:
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
VOP_UNLOCK(vp, 0, ap->a_p);
if (error)
return (error);
if (bdev_buffered) {
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, p, 0, 0);
VOP_UNLOCK(vp, 0, p);
if (error)
return (error);
}
mode = S_IFBLK;
break;
@ -766,7 +795,7 @@ spec_close(ap)
} else if (vcount(vp) > 1) {
return (0);
}
return (devsw(dev)->d_close(dev, ap->a_fflag, mode, ap->a_p));
return (devsw(dev)->d_close(dev, ap->a_fflag, mode, p));
}
/*

1
sys/sys/vnode.h
View File

@ -278,7 +278,6 @@ extern struct vm_zone *namei_zone;
extern int prtactive; /* nonzero to call vprint() */
extern struct vattr va_null; /* predefined null vattr structure */
extern int vfs_ioopt;
extern int enable_userblk_io;
/*
* Macro/function to check for client cache inconsistency w.r.t. leasing.