freebsd-dev/sys/ufs/mfs/mfs_vnops.c
Poul-Henning Kamp 21144e3bf1 Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new
field in struct buf: b_iocmd.  The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue.  It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users:  Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00

430 lines
11 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)mfs_vnops.c 8.11 (Berkeley) 5/22/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/sysproto.h>
#include <sys/mman.h>
#include <sys/conf.h>
#include <ufs/mfs/mfsnode.h>
#include <ufs/mfs/mfs_extern.h>
static int mfs_badop __P((struct vop_generic_args *));
static int mfs_bmap __P((struct vop_bmap_args *));
static int mfs_close __P((struct vop_close_args *));
static int mfs_fsync __P((struct vop_fsync_args *));
static int mfs_freeblks __P((struct vop_freeblks_args *));
static int mfs_inactive __P((struct vop_inactive_args *)); /* XXX */
static int mfs_open __P((struct vop_open_args *));
static int mfs_reclaim __P((struct vop_reclaim_args *)); /* XXX */
static int mfs_print __P((struct vop_print_args *)); /* XXX */
static int mfs_strategy __P((struct vop_strategy_args *)); /* XXX */
static int mfs_getpages __P((struct vop_getpages_args *)); /* XXX */
/*
* mfs vnode operations.
*/
vop_t **mfs_vnodeop_p;
static struct vnodeopv_entry_desc mfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) mfs_badop },
{ &vop_bmap_desc, (vop_t *) mfs_bmap },
{ &vop_bwrite_desc, (vop_t *) vop_defaultop },
{ &vop_close_desc, (vop_t *) mfs_close },
{ &vop_freeblks_desc, (vop_t *) mfs_freeblks },
{ &vop_fsync_desc, (vop_t *) mfs_fsync },
{ &vop_getpages_desc, (vop_t *) mfs_getpages },
{ &vop_inactive_desc, (vop_t *) mfs_inactive },
{ &vop_ioctl_desc, (vop_t *) vop_enotty },
{ &vop_islocked_desc, (vop_t *) vop_defaultop },
{ &vop_lock_desc, (vop_t *) vop_defaultop },
{ &vop_open_desc, (vop_t *) mfs_open },
{ &vop_print_desc, (vop_t *) mfs_print },
{ &vop_reclaim_desc, (vop_t *) mfs_reclaim },
{ &vop_strategy_desc, (vop_t *) mfs_strategy },
{ &vop_unlock_desc, (vop_t *) vop_defaultop },
{ NULL, NULL }
};
static struct vnodeopv_desc mfs_vnodeop_opv_desc =
{ &mfs_vnodeop_p, mfs_vnodeop_entries };
VNODEOP_SET(mfs_vnodeop_opv_desc);
/*
* Vnode Operations.
*
* Open called to allow memory filesystem to initialize and
* validate before actual IO. Record our process identifier
* so we can tell when we are doing I/O to ourself.
*/
/* ARGSUSED */
static int
mfs_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
if (ap->a_vp->v_type != VBLK) {
panic("mfs_open not VBLK");
/* NOTREACHED */
}
return (0);
}
static int
mfs_fsync(ap)
struct vop_fsync_args *ap;
{
return (VOCALL(spec_vnodeop_p, VOFFSET(vop_fsync), ap));
}
/*
* mfs_freeblks() - hook to allow us to free physical memory.
*
* We implement the BIO_DELETE strategy. We can't just madvise()
* here because we have to do it in the correct order vs other bio
* requests, so we queue it.
*
* Note: geteblk() sets B_INVAL. We leave it set to guarentee buffer
* throw-away on brelse()? XXX
*/
static int
mfs_freeblks(ap)
struct vop_freeblks_args /* {
struct vnode *a_vp;
daddr_t a_addr;
daddr_t a_length;
} */ *ap;
{
struct buf *bp;
struct vnode *vp;
if (!vfinddev(ap->a_vp->v_rdev, VBLK, &vp) || vp->v_usecount == 0)
panic("mfs_freeblks: bad dev");
bp = geteblk(ap->a_length);
bp->b_flags |= B_ASYNC;
bp->b_iocmd = BIO_DELETE;
bp->b_dev = ap->a_vp->v_rdev;
bp->b_blkno = ap->a_addr;
bp->b_offset = dbtob(ap->a_addr);
bp->b_bcount = ap->a_length;
BUF_KERNPROC(bp);
VOP_STRATEGY(vp, bp);
return(0);
}
/*
* Pass I/O requests to the memory filesystem process.
*/
static int
mfs_strategy(ap)
struct vop_strategy_args /* {
struct vnode *a_vp;
struct buf *a_bp;
} */ *ap;
{
register struct buf *bp = ap->a_bp;
register struct mfsnode *mfsp;
struct vnode *vp;
struct proc *p = curproc; /* XXX */
int s;
if (!vfinddev(bp->b_dev, VBLK, &vp) || vp->v_usecount == 0)
panic("mfs_strategy: bad dev");
mfsp = VTOMFS(vp);
/*
* splbio required for queueing/dequeueing, in case of forwarded
* BPs from bio interrupts (?). It may not be necessary.
*/
s = splbio();
if (mfsp->mfs_pid == 0) {
/*
* mini-root. Note: BIO_DELETE not supported at the moment,
* I'm not sure what kind of dataspace b_data is in.
*/
caddr_t base;
base = mfsp->mfs_baseoff + (bp->b_blkno << DEV_BSHIFT);
if (bp->b_iocmd == BIO_DELETE)
;
if (bp->b_iocmd == BIO_READ)
bcopy(base, bp->b_data, bp->b_bcount);
else
bcopy(bp->b_data, base, bp->b_bcount);
biodone(bp);
} else if (mfsp->mfs_pid == p->p_pid) {
/*
* VOP to self
*/
splx(s);
mfs_doio(bp, mfsp);
s = splbio();
} else {
/*
* VOP from some other process, queue to MFS process and
* wake it up.
*/
bufq_insert_tail(&mfsp->buf_queue, bp);
wakeup((caddr_t)vp);
}
splx(s);
return (0);
}
/*
* Memory file system I/O.
*
* Trivial on the HP since buffer has already been mapping into KVA space.
*
* Read and Write are handled with a simple copyin and copyout.
*
* We also partially support VOP_FREEBLKS() via BIO_DELETE. We can't implement
* completely -- for example, on fragments or inode metadata, but we can
* implement it for page-aligned requests.
*/
void
mfs_doio(bp, mfsp)
register struct buf *bp;
struct mfsnode *mfsp;
{
caddr_t base = mfsp->mfs_baseoff + (bp->b_blkno << DEV_BSHIFT);
if (bp->b_iocmd == BIO_DELETE) {
/*
* Implement BIO_DELETE, which allows the filesystem to tell
* a block device when blocks are no longer needed (like when
* a file is deleted). We use the hook to MADV_FREE the VM.
* This makes an MFS filesystem work as well or better then
* a sun-style swap-mounted filesystem.
*/
int bytes = bp->b_bcount;
if ((vm_offset_t)base & PAGE_MASK) {
int n = PAGE_SIZE - ((vm_offset_t)base & PAGE_MASK);
bytes -= n;
base += n;
}
if (bytes > 0) {
struct madvise_args uap;
bytes &= ~PAGE_MASK;
if (bytes != 0) {
bzero(&uap, sizeof(uap));
uap.addr = base;
uap.len = bytes;
uap.behav = MADV_FREE;
madvise(curproc, &uap);
}
}
bp->b_error = 0;
} else if (bp->b_iocmd == BIO_READ) {
/*
* Read data from our 'memory' disk
*/
bp->b_error = copyin(base, bp->b_data, bp->b_bcount);
} else {
/*
* Write data to our 'memory' disk
*/
bp->b_error = copyout(bp->b_data, base, bp->b_bcount);
}
if (bp->b_error)
bp->b_flags |= B_ERROR;
biodone(bp);
}
/*
* This is a noop, simply returning what one has been given.
*/
static int
mfs_bmap(ap)
struct vop_bmap_args /* {
struct vnode *a_vp;
ufs_daddr_t a_bn;
struct vnode **a_vpp;
ufs_daddr_t *a_bnp;
int *a_runp;
} */ *ap;
{
if (ap->a_vpp != NULL)
*ap->a_vpp = ap->a_vp;
if (ap->a_bnp != NULL)
*ap->a_bnp = ap->a_bn;
if (ap->a_runp != NULL)
*ap->a_runp = 0;
return (0);
}
/*
* Memory filesystem close routine
*/
/* ARGSUSED */
static int
mfs_close(ap)
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct mfsnode *mfsp = VTOMFS(vp);
register struct buf *bp;
int error;
/*
* Finish any pending I/O requests.
*/
while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) {
bufq_remove(&mfsp->buf_queue, bp);
mfs_doio(bp, mfsp);
wakeup((caddr_t)bp);
}
/*
* On last close of a memory filesystem
* we must invalidate any in core blocks, so that
* we can, free up its vnode.
*/
if ((error = vinvalbuf(vp, 1, ap->a_cred, ap->a_p, 0, 0)) != 0)
return (error);
/*
* There should be no way to have any more uses of this
* vnode, so if we find any other uses, it is a panic.
*/
if (vp->v_usecount > 1)
printf("mfs_close: ref count %d > 1\n", vp->v_usecount);
if (vp->v_usecount > 1 || (bufq_first(&mfsp->buf_queue) != NULL))
panic("mfs_close");
/*
* Send a request to the filesystem server to exit.
*/
mfsp->mfs_active = 0;
wakeup((caddr_t)vp);
return (0);
}
/*
* Memory filesystem inactive routine
*/
/* ARGSUSED */
static int
mfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct mfsnode *mfsp = VTOMFS(vp);
if (bufq_first(&mfsp->buf_queue) != NULL)
panic("mfs_inactive: not inactive (next buffer %p)",
bufq_first(&mfsp->buf_queue));
VOP_UNLOCK(vp, 0, ap->a_p);
return (0);
}
/*
* Reclaim a memory filesystem devvp so that it can be reused.
*/
static int
mfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
FREE(vp->v_data, M_MFSNODE);
vp->v_data = NULL;
return (0);
}
/*
* Print out the contents of an mfsnode.
*/
static int
mfs_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
register struct mfsnode *mfsp = VTOMFS(ap->a_vp);
printf("tag VT_MFS, pid %ld, base %p, size %ld\n",
(long)mfsp->mfs_pid, (void *)mfsp->mfs_baseoff, mfsp->mfs_size);
return (0);
}
/*
* Block device bad operation
*/
static int
mfs_badop(struct vop_generic_args *ap)
{
int i;
printf("mfs_badop[%s]\n", ap->a_desc->vdesc_name);
i = vop_defaultop(ap);
printf("mfs_badop[%s] = %d\n", ap->a_desc->vdesc_name,i);
return (i);
}
static int
mfs_getpages(ap)
struct vop_getpages_args *ap;
{
return (VOCALL(spec_vnodeop_p, VOFFSET(vop_getpages), ap));
}