Author: kib
Date: Mon Dec 24 13:29:22 2012
New Revision: 244660
URL: http://svnweb.freebsd.org/changeset/base/244660
Log:
MFC r242476:
The r241025 fixed the case when a binary, executed from nullfs mount,
was still possible to open for write from the lower filesystem. There
is a symmetric situation where the binary could already has file
descriptors opened for write, but it can be executed from the nullfs
overlay.
Handle the issue by passing one v_writecount reference to the lower
vnode if nullfs vnode has non-zero v_writecount.
Modified:
stable/9/sys/compat/linux/linux_misc.c
stable/9/sys/fs/nullfs/null_vnops.c
stable/9/sys/fs/unionfs/union_subr.c
stable/9/sys/i386/ibcs2/imgact_coff.c
stable/9/sys/kern/kern_exec.c
stable/9/sys/kern/vfs_default.c
stable/9/sys/kern/vfs_vnops.c
stable/9/sys/kern/vnode_if.src
stable/9/sys/ufs/ufs/ufs_extattr.c
stable/9/sys/vm/vnode_pager.c
Directory Properties:
stable/9/sys/ (props changed)
stable/9/sys/fs/ (props changed)
Modified: stable/9/sys/compat/linux/linux_misc.c
==============================================================================
--- stable/9/sys/compat/linux/linux_misc.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/compat/linux/linux_misc.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -232,8 +232,7 @@ linux_uselib(struct thread *td, struct l
unsigned long bss_size;
char *library;
ssize_t aresid;
- int error;
- int locked, vfslocked;
+ int error, locked, vfslocked, writecount;
LCONVPATHEXIST(td, args->library, &library);
@@ -265,7 +264,10 @@ linux_uselib(struct thread *td, struct l
locked = 1;
/* Writable? */
- if (vp->v_writecount) {
+ error = VOP_GET_WRITECOUNT(vp, &writecount);
+ if (error != 0)
+ goto cleanup;
+ if (writecount != 0) {
error = ETXTBSY;
goto cleanup;
}
Modified: stable/9/sys/fs/nullfs/null_vnops.c
==============================================================================
--- stable/9/sys/fs/nullfs/null_vnops.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/fs/nullfs/null_vnops.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -329,6 +329,26 @@ null_bypass(struct vop_generic_args *ap)
return (error);
}
+static int
+null_add_writecount(struct vop_add_writecount_args *ap)
+{
+ struct vnode *lvp, *vp;
+ int error;
+
+ vp = ap->a_vp;
+ lvp = NULLVPTOLOWERVP(vp);
+ KASSERT(vp->v_writecount + ap->a_inc >= 0, ("wrong writecount inc"));
+ if (vp->v_writecount > 0 && vp->v_writecount + ap->a_inc == 0)
+ error = VOP_ADD_WRITECOUNT(lvp, -1);
+ else if (vp->v_writecount == 0 && vp->v_writecount + ap->a_inc > 0)
+ error = VOP_ADD_WRITECOUNT(lvp, 1);
+ else
+ error = 0;
+ if (error == 0)
+ vp->v_writecount += ap->a_inc;
+ return (error);
+}
+
/*
* We have to carry on the locking protocol on the null layer vnodes
* as we progress through the tree. We also have to enforce read-only
@@ -826,4 +846,5 @@ struct vop_vector null_vnodeops = {
.vop_unlock = null_unlock,
.vop_vptocnp = null_vptocnp,
.vop_vptofh = null_vptofh,
+ .vop_add_writecount = null_add_writecount,
};
Modified: stable/9/sys/fs/unionfs/union_subr.c
==============================================================================
--- stable/9/sys/fs/unionfs/union_subr.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/fs/unionfs/union_subr.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -954,7 +954,7 @@ unionfs_vn_create_on_upper(struct vnode
vput(vp);
goto unionfs_vn_create_on_upper_free_out1;
}
- vp->v_writecount++;
+ VOP_ADD_WRITECOUNT(vp, 1);
*vpp = vp;
unionfs_vn_create_on_upper_free_out1:
@@ -1089,7 +1089,7 @@ unionfs_copyfile(struct unionfs_node *un
}
}
VOP_CLOSE(uvp, FWRITE, cred, td);
- uvp->v_writecount--;
+ VOP_ADD_WRITECOUNT(uvp, -1);
vn_finished_write(mp);
Modified: stable/9/sys/i386/ibcs2/imgact_coff.c
==============================================================================
--- stable/9/sys/i386/ibcs2/imgact_coff.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/i386/ibcs2/imgact_coff.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -168,7 +168,7 @@ coff_load_file(struct thread *td, char *
unsigned long text_offset = 0, text_address = 0, text_size = 0;
unsigned long data_offset = 0, data_address = 0, data_size = 0;
unsigned long bss_size = 0;
- int i;
+ int i, writecount;
NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME,
UIO_SYSSPACE, name, td);
@@ -181,7 +181,10 @@ coff_load_file(struct thread *td, char *
if (vp == NULL)
return ENOEXEC;
- if (vp->v_writecount) {
+ error = VOP_GET_WRITECOUNT(vp, &writecount);
+ if (error != 0)
+ goto fail;
+ if (writecount != 0) {
error = ETXTBSY;
goto fail;
}
Modified: stable/9/sys/kern/kern_exec.c
==============================================================================
--- stable/9/sys/kern/kern_exec.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/kern/kern_exec.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -1393,7 +1393,7 @@ exec_check_permissions(imgp)
struct vnode *vp = imgp->vp;
struct vattr *attr = imgp->attr;
struct thread *td;
- int error;
+ int error, writecount;
td = curthread;
@@ -1438,7 +1438,10 @@ exec_check_permissions(imgp)
* Check number of open-for-writes on the file and deny execution
* if there are any.
*/
- if (vp->v_writecount)
+ error = VOP_GET_WRITECOUNT(vp, &writecount);
+ if (error != 0)
+ return (error);
+ if (writecount != 0)
return (ETXTBSY);
/*
Modified: stable/9/sys/kern/vfs_default.c
==============================================================================
--- stable/9/sys/kern/vfs_default.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/kern/vfs_default.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -81,6 +81,8 @@ static int dirent_exists(struct vnode *v
static int vop_stdis_text(struct vop_is_text_args *ap);
static int vop_stdset_text(struct vop_set_text_args *ap);
static int vop_stdunset_text(struct vop_unset_text_args *ap);
+static int vop_stdget_writecount(struct vop_get_writecount_args *ap);
+static int vop_stdadd_writecount(struct vop_add_writecount_args *ap);
/*
* This vnode table stores what we want to do if the filesystem doesn't
@@ -133,6 +135,8 @@ struct vop_vector default_vnodeops = {
.vop_is_text = vop_stdis_text,
.vop_set_text = vop_stdset_text,
.vop_unset_text = vop_stdunset_text,
+ .vop_get_writecount = vop_stdget_writecount,
+ .vop_add_writecount = vop_stdadd_writecount,
};
/*
@@ -1103,6 +1107,22 @@ vop_stdunset_text(struct vop_unset_text_
return (0);
}
+static int
+vop_stdget_writecount(struct vop_get_writecount_args *ap)
+{
+
+ *ap->a_writecount = ap->a_vp->v_writecount;
+ return (0);
+}
+
+static int
+vop_stdadd_writecount(struct vop_add_writecount_args *ap)
+{
+
+ ap->a_vp->v_writecount += ap->a_inc;
+ return (0);
+}
+
/*
* vfs default ops
* used to fill the vfs function table to get reasonable default return values.
Modified: stable/9/sys/kern/vfs_vnops.c
==============================================================================
--- stable/9/sys/kern/vfs_vnops.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/kern/vfs_vnops.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -252,7 +252,7 @@ restart:
goto bad;
if (fmode & FWRITE)
- vp->v_writecount++;
+ VOP_ADD_WRITECOUNT(vp, 1);
*flagp = fmode;
ASSERT_VOP_LOCKED(vp, "vn_open_cred");
if (!mpsafe)
@@ -314,7 +314,7 @@ vn_close(vp, flags, file_cred, td)
if (flags & FWRITE) {
VNASSERT(vp->v_writecount > 0, vp,
("vn_close: negative writecount"));
- vp->v_writecount--;
+ VOP_ADD_WRITECOUNT(vp, -1);
}
error = VOP_CLOSE(vp, flags, file_cred, td);
vput(vp);
Modified: stable/9/sys/kern/vnode_if.src
==============================================================================
--- stable/9/sys/kern/vnode_if.src Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/kern/vnode_if.src Mon Dec 24 13:29:22 2012
(r244660)
@@ -676,6 +676,20 @@ vop_unset_text {
IN struct vnode *vp;
};
+%% get_writecount vp L L L
+
+vop_get_writecount {
+ IN struct vnode *vp;
+ OUT int *writecount;
+};
+
+%% add_writecount vp E E E
+
+vop_add_writecount {
+ IN struct vnode *vp;
+ IN int inc;
+};
+
# The VOPs below are spares at the end of the table to allow new VOPs to be
# added in stable branches without breaking the KBI. New VOPs in HEAD should
# be added above these spares. When merging a new VOP to a stable branch,
Modified: stable/9/sys/ufs/ufs/ufs_extattr.c
==============================================================================
--- stable/9/sys/ufs/ufs/ufs_extattr.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/ufs/ufs/ufs_extattr.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -334,7 +334,7 @@ ufs_extattr_enable_with_open(struct ufsm
return (error);
}
- vp->v_writecount++;
+ VOP_ADD_WRITECOUNT(vp, 1);
vref(vp);
Modified: stable/9/sys/vm/vnode_pager.c
==============================================================================
--- stable/9/sys/vm/vnode_pager.c Mon Dec 24 13:24:55 2012
(r244659)
+++ stable/9/sys/vm/vnode_pager.c Mon Dec 24 13:29:22 2012
(r244660)
@@ -272,7 +272,7 @@ vnode_pager_dealloc(object)
ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
if (object->un_pager.vnp.writemappings > 0) {
object->un_pager.vnp.writemappings = 0;
- vp->v_writecount--;
+ VOP_ADD_WRITECOUNT(vp, -1);
}
vp->v_object = NULL;
VOP_UNSET_TEXT(vp);
@@ -1216,10 +1216,10 @@ vnode_pager_update_writecount(vm_object_
vp = object->handle;
if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
ASSERT_VOP_ELOCKED(vp, "v_writecount inc");
- vp->v_writecount++;
+ VOP_ADD_WRITECOUNT(vp, 1);
} else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
ASSERT_VOP_ELOCKED(vp, "v_writecount dec");
- vp->v_writecount--;
+ VOP_ADD_WRITECOUNT(vp, -1);
}
VM_OBJECT_UNLOCK(object);
}
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