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authordg <dg@FreeBSD.org>1996-06-12 03:37:57 +0000
committerdg <dg@FreeBSD.org>1996-06-12 03:37:57 +0000
commit5026fc1c3662189cacaad4f0eb1fc0222ec8def1 (patch)
tree0244ce546b0fc6e415af50b64cc8c473ae6be049 /sys/miscfs/umapfs
parent6e349b6b4756260c2efd6d1e925c366e50db77d0 (diff)
downloadFreeBSD-src-5026fc1c3662189cacaad4f0eb1fc0222ec8def1.zip
FreeBSD-src-5026fc1c3662189cacaad4f0eb1fc0222ec8def1.tar.gz
Moved the fsnode MALLOC to before the call to getnewvnode() so that the
process won't possibly block before filling in the fsnode pointer (v_data) which might be dereferenced during a sync since the vnode is put on the mnt_vnodelist by getnewvnode. Pointed out by Matt Day <mday@artisoft.com>
Diffstat (limited to 'sys/miscfs/umapfs')
-rw-r--r--sys/miscfs/umapfs/umap_subr.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/sys/miscfs/umapfs/umap_subr.c b/sys/miscfs/umapfs/umap_subr.c
index 0267584..fe1ec56 100644
--- a/sys/miscfs/umapfs/umap_subr.c
+++ b/sys/miscfs/umapfs/umap_subr.c
@@ -35,7 +35,7 @@
*
* @(#)umap_subr.c 8.6 (Berkeley) 1/26/94
*
- * $Id: umap_subr.c,v 1.5 1995/12/03 14:38:57 bde Exp $
+ * $Id: umap_subr.c,v 1.6 1995/12/03 14:54:39 bde Exp $
*/
#include <sys/param.h>
@@ -222,13 +222,23 @@ umap_node_alloc(mp, lowervp, vpp)
struct vnode *othervp, *vp;
int error;
+ /* XXX This routine probably needs a node_alloc lock */
+
+ /*
+ * Do the MALLOC before the getnewvnode since doing so afterward
+ * might cause a bogus v_data pointer to get dereferenced
+ * elsewhere if MALLOC should block.
+ */
+ MALLOC(xp, struct umap_node *, sizeof(struct umap_node),
+ M_TEMP, M_WAITOK);
+
error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, vpp);
- if (error)
+ if (error) {
+ FREE(xp, M_TEMP);
return (error);
+ }
vp = *vpp;
- MALLOC(xp, struct umap_node *, sizeof(struct umap_node),
- M_TEMP, M_WAITOK);
vp->v_type = lowervp->v_type;
xp->umap_vnode = vp;
vp->v_data = xp;
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