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Don't follow null bdevsw pointers. The `major(dev) < nblkdev' test rotted

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when bdevsw[] became sparse.  We still depend on magic to avoid having to
check that (v_rdev) device numbers in vnodes are not NODEV.

Removed a redundant `major(dev) < nblkdev' test instead of updating it.

Don't follow a garbage bdevsw pointer for attempts to swap on empty
regular files.  This case currently can't happen.  Swapping on regular
files is ifdefed out in swapon() and isn't attempted for empty files
in nfs_mountroot().
This commit is contained in:
bde 1998-10-25 19:24:04 +00:00
parent 5a7ea1209a
commit 9fafc47653
1 changed files with 4 additions and 7 deletions
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11
sys/vm/vm_swap.c
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@ -31,7 +31,7 @@
* SUCH DAMAGE. * SUCH DAMAGE.
* *
* @(#)vm_swap.c 8.5 (Berkeley) 2/17/94 * @(#)vm_swap.c 8.5 (Berkeley) 2/17/94
* $Id: vm_swap.c,v 1.55 1998/07/04 20:45:42 julian Exp $ * $Id: vm_swap.c,v 1.56 1998/07/04 22:30:26 julian Exp $
*/ */
#include "opt_devfs.h" #include "opt_devfs.h"
@ -203,8 +203,8 @@ swapon(p, uap)
switch (vp->v_type) { switch (vp->v_type) {
case VBLK: case VBLK:
dev = (dev_t) vp->v_rdev; dev = vp->v_rdev;
if (major(dev) >= nblkdev) { if (major(dev) >= nblkdev || bdevsw[major(dev)] == NULL) {
error = ENXIO; error = ENXIO;
break; break;
} }
@ -264,14 +264,11 @@ swaponvp(p, vp, dev, nblks)
} }
return EINVAL; return EINVAL;
found: found:
if (dev != NODEV && (major(dev) >= nblkdev))
return (ENXIO);
error = VOP_OPEN(vp, FREAD | FWRITE, p->p_ucred, p); error = VOP_OPEN(vp, FREAD | FWRITE, p->p_ucred, p);
if (error) if (error)
return (error); return (error);
if (nblks == 0 && (bdevsw[major(dev)]->d_psize == 0 || if (nblks == 0 && dev != NODEV && (bdevsw[major(dev)]->d_psize == 0 ||
(nblks = (*bdevsw[major(dev)]->d_psize) (dev)) == -1)) { (nblks = (*bdevsw[major(dev)]->d_psize) (dev)) == -1)) {
(void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p); (void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p);
return (ENXIO); return (ENXIO);