Author: kib
Date: Sun Jun 20 13:35:16 2010
New Revision: 209367
URL: http://svn.freebsd.org/changeset/base/209367
Log:
Ensure that VOP_ACCESSX is called with exclusively locked vnode for
the kernel compiled with QUOTA option. ufs_accessx() upgrades the vdp
vnode lock from shared to exclusive to assign the dquot structure to
the vnode, and ufs_delete_denied() is called when tvp is locked. Since
upgrade drops shared lock when non-blocked upgrade failed, LOR is there.
Reported and tested by: Dmitry Pryanishnikov <lynx.ripe gmail com>
Tested by: pho
PR: kern/147890
MFC after: 1 week
Modified:
head/sys/ufs/ufs/ufs_lookup.c
Modified: head/sys/ufs/ufs/ufs_lookup.c
==============================================================================
--- head/sys/ufs/ufs/ufs_lookup.c Sun Jun 20 12:52:33 2010
(r209366)
+++ head/sys/ufs/ufs/ufs_lookup.c Sun Jun 20 13:35:16 2010
(r209367)
@@ -77,6 +77,32 @@ SYSCTL_INT(_debug, OID_AUTO, dircheck, C
/* true if old FS format...*/
#define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
+#ifdef QUOTA
+static int
+ufs_lookup_upgrade_lock(struct vnode *vp)
+{
+ int error;
+
+ ASSERT_VOP_LOCKED(vp, __FUNCTION__);
+ if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
+ return (0);
+
+ error = 0;
+
+ /*
+ * Upgrade vnode lock, since getinoquota()
+ * requires exclusive lock to modify inode.
+ */
+ vhold(vp);
+ vn_lock(vp, LK_UPGRADE | LK_RETRY);
+ VI_LOCK(vp);
+ if (vp->v_iflag & VI_DOOMED)
+ error = ENOENT;
+ vdropl(vp);
+ return (error);
+}
+#endif
+
static int
ufs_delete_denied(struct vnode *vdp, struct vnode *tdp, struct ucred *cred,
struct thread *td)
@@ -232,6 +258,13 @@ ufs_lookup_ino(struct vnode *vdp, struct
vnode_create_vobject(vdp, DIP(dp, i_size), cnp->cn_thread);
bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
+#ifdef QUOTA
+ if ((nameiop == DELETE || nameiop == RENAME) && (flags & ISLASTCN)) {
+ error = ufs_lookup_upgrade_lock(vdp);
+ if (error != 0)
+ return (error);
+ }
+#endif
restart:
bp = NULL;
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