freebsd-skq/sys/tools/vnode_if.awk
jhb ca1e2e0739 Further refine the handling of stop signals in the NFS client. The
changes in r246417 were incomplete as they did not add explicit calls to
sigdeferstop() around all the places that previously passed SBDRY to
_sleep().  In addition, nfs_getcacheblk() could trigger a write RPC from
getblk() resulting in sigdeferstop() recursing.  Rather than manually
deferring stop signals in specific places, change the VFS_*() and VOP_*()
methods to defer stop signals for filesystems which request this behavior
via a new VFCF_SBDRY flag.  Note that this has to be a VFC flag rather than
a MNTK flag so that it works properly with VFS_MOUNT() when the mount is
not yet fully constructed.  For now, only the NFS clients are set this new
flag in VFS_SET().

A few other related changes:
- Add an assertion to ensure that TDF_SBDRY doesn't leak to userland.
- When a lookup request uses VOP_READLINK() to follow a symlink, mark
  the request as being on behalf of the thread performing the lookup
  (cnp_thread) rather than using a NULL thread pointer.  This causes
  NFS to properly handle signals during this VOP on an interruptible
  mount.

PR:		kern/176179
Reported by:	Russell Cattelan (sigdeferstop() recursion)
Reviewed by:	kib
MFC after:	1 month
2013-02-21 19:02:50 +00:00

436 lines
12 KiB
Awk

#!/usr/bin/awk -f
#-
# Copyright (c) 1992, 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.
# 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.
#
# @(#)vnode_if.sh 8.1 (Berkeley) 6/10/93
# $FreeBSD$
#
# Script to produce VFS front-end sugar.
#
# usage: vnode_if.awk <srcfile> [-c | -h | -p | -q]
# (where <srcfile> is currently /sys/kern/vnode_if.src)
# The source file must have a .src extension
#
function usage()
{
print "usage: vnode_if.awk <srcfile> [-c|-h|-p|-q]";
exit 1;
}
function die(msg, what)
{
printf srcfile "(" fnr "): " > "/dev/stderr";
printf msg "\n", what > "/dev/stderr";
exit 1;
}
function t_spc(type)
{
# Append a space if the type is not a pointer
return (type ~ /\*$/) ? type : type " ";
}
# These are just for convenience ...
function printc(s) {print s > cfile;}
function printh(s) {print s > hfile;}
function printp(s) {print s > pfile;}
function printq(s) {print s > qfile;}
function add_debug_code(name, arg, pos, ind)
{
if (arg == "vpp")
star = "*";
else
star = "";
if (lockdata[name, arg, pos] && (lockdata[name, arg, pos] != "-")) {
printc(ind"ASSERT_VI_UNLOCKED("star"a->a_"arg", \""uname"\");");
# Add assertions for locking
if (lockdata[name, arg, pos] == "L")
printc(ind"ASSERT_VOP_LOCKED(" star "a->a_"arg", \""uname"\");");
else if (lockdata[name, arg, pos] == "U")
printc(ind"ASSERT_VOP_UNLOCKED(" star "a->a_"arg", \""uname"\");");
else if (lockdata[name, arg, pos] == "E")
printc(ind"ASSERT_VOP_ELOCKED(" star "a->a_"arg", \""uname"\");");
else if (0) {
# XXX More checks!
}
}
}
function add_pre(name)
{
if (lockdata[name, "pre"]) {
printc("\t"lockdata[name, "pre"]"(a);");
}
}
function add_post(name)
{
if (lockdata[name, "post"]) {
printc("\t"lockdata[name, "post"]"(a, rc);");
}
}
function find_arg_with_type (type)
{
for (jj = 0; jj < numargs; jj++) {
if (types[jj] == type) {
return "VOPARG_OFFSETOF(struct " \
name "_args,a_" args[jj] ")";
}
}
return "VDESC_NO_OFFSET";
}
BEGIN{
# Process the command line
for (i = 1; i < ARGC; i++) {
arg = ARGV[i];
if (arg !~ /^-[chpq]+$/ && arg !~ /\.src$/)
usage();
if (arg ~ /^-.*c/)
cfile = "vnode_if.c";
if (arg ~ /^-.*h/)
hfile = "vnode_if.h";
if (arg ~ /^-.*p/)
pfile = "vnode_if_newproto.h";
if (arg ~ /^-.*q/)
qfile = "vnode_if_typedef.h";
if (arg ~ /\.src$/)
srcfile = arg;
}
ARGC = 1;
if (!cfile && !hfile && !pfile && !qfile)
exit 0;
if (!srcfile)
usage();
common_head = \
"/*\n" \
" * This file is produced automatically.\n" \
" * Do not modify anything in here by hand.\n" \
" *\n" \
" * Created from $FreeBSD$\n" \
" */\n" \
"\n";
if (pfile) {
printp(common_head)
printp("struct vop_vector {")
printp("\tstruct vop_vector\t*vop_default;")
printp("\tvop_bypass_t\t*vop_bypass;")
}
if (qfile) {
printq(common_head)
}
if (hfile) {
printh(common_head "extern struct vnodeop_desc vop_default_desc;");
printh("#include \"vnode_if_typedef.h\"")
printh("#include \"vnode_if_newproto.h\"")
}
if (cfile) {
printc(common_head \
"#include \"opt_kdtrace.h\"\n" \
"\n" \
"#include <sys/param.h>\n" \
"#include <sys/event.h>\n" \
"#include <sys/kernel.h>\n" \
"#include <sys/mount.h>\n" \
"#include <sys/sdt.h>\n" \
"#include <sys/signalvar.h>\n" \
"#include <sys/systm.h>\n" \
"#include <sys/vnode.h>\n" \
"\n" \
"SDT_PROVIDER_DECLARE(vfs);\n" \
"\n" \
"struct vnodeop_desc vop_default_desc = {\n" \
" \"default\",\n" \
" 0,\n" \
" (vop_bypass_t *)vop_panic,\n" \
" NULL,\n" \
" VDESC_NO_OFFSET,\n" \
" VDESC_NO_OFFSET,\n" \
" VDESC_NO_OFFSET,\n" \
" VDESC_NO_OFFSET,\n" \
"};\n");
}
while ((getline < srcfile) > 0) {
fnr++;
if (NF == 0)
continue;
if ($1 ~ /^%%/) {
if (NF != 6 ||
$2 !~ /^[a-z_]+$/ || $3 !~ /^[a-z]+$/ ||
$4 !~ /^.$/ || $5 !~ /^.$/ || $6 !~ /^.$/) {
die("Invalid %s construction", "%%");
continue;
}
lockdata["vop_" $2, $3, "Entry"] = $4;
lockdata["vop_" $2, $3, "OK"] = $5;
lockdata["vop_" $2, $3, "Error"] = $6;
continue;
}
if ($1 ~ /^%!/) {
if (NF != 4 ||
($3 != "pre" && $3 != "post")) {
die("Invalid %s construction", "%!");
continue;
}
lockdata["vop_" $2, $3] = $4;
continue;
}
if ($1 ~ /^#/)
continue;
# Get the function name.
name = $1;
uname = toupper(name);
# Get the function arguments.
for (numargs = 0; ; ++numargs) {
if ((getline < srcfile) <= 0) {
die("Unable to read through the arguments for \"%s\"",
name);
}
fnr++;
if ($1 ~ /^\};/)
break;
# Delete comments, if any.
gsub (/\/\*.*\*\//, "");
# Condense whitespace and delete leading/trailing space.
gsub(/[[:space:]]+/, " ");
sub(/^ /, "");
sub(/ $/, "");
# Pick off direction.
if ($1 != "INOUT" && $1 != "IN" && $1 != "OUT")
die("No IN/OUT direction for \"%s\".", $0);
dirs[numargs] = $1;
sub(/^[A-Z]* /, "");
if ((reles[numargs] = $1) == "WILLRELE")
sub(/^[A-Z]* /, "");
else
reles[numargs] = "WONTRELE";
# kill trailing ;
if (sub(/;$/, "") < 1)
die("Missing end-of-line ; in \"%s\".", $0);
# pick off variable name
if ((argp = match($0, /[A-Za-z0-9_]+$/)) < 1)
die("Missing var name \"a_foo\" in \"%s\".", $0);
args[numargs] = substr($0, argp);
$0 = substr($0, 1, argp - 1);
# what is left must be type
# remove trailing space (if any)
sub(/ $/, "");
types[numargs] = $0;
}
if (numargs > 4)
ctrargs = 4;
else
ctrargs = numargs;
ctrstr = ctrargs "(KTR_VOP, \"VOP\", \"" uname "\", (uintptr_t)a,\n\t ";
ctrstr = ctrstr "\"" args[0] ":0x%jX\", (uintptr_t)a->a_" args[0];
for (i = 1; i < ctrargs; ++i)
ctrstr = ctrstr ", \"" args[i] ":0x%jX\", a->a_" args[i];
ctrstr = ctrstr ");";
if (pfile) {
printp("\t"name"_t\t*"name";")
}
if (qfile) {
printq("struct "name"_args;")
printq("typedef int "name"_t(struct "name"_args *);\n")
}
if (hfile) {
# Print out the vop_F_args structure.
printh("struct "name"_args {\n\tstruct vop_generic_args a_gen;");
for (i = 0; i < numargs; ++i)
printh("\t" t_spc(types[i]) "a_" args[i] ";");
printh("};");
printh("");
# Print out extern declaration.
printh("extern struct vnodeop_desc " name "_desc;");
printh("");
# Print out function prototypes.
printh("int " uname "_AP(struct " name "_args *);");
printh("int " uname "_APV(struct vop_vector *vop, struct " name "_args *);");
printh("");
printh("static __inline int " uname "(");
for (i = 0; i < numargs; ++i) {
printh("\t" t_spc(types[i]) args[i] \
(i < numargs - 1 ? "," : ")"));
}
printh("{");
printh("\tstruct " name "_args a;");
printh("");
printh("\ta.a_gen.a_desc = &" name "_desc;");
for (i = 0; i < numargs; ++i)
printh("\ta.a_" args[i] " = " args[i] ";");
printh("\treturn (" uname "_APV("args[0]"->v_op, &a));");
printh("}");
printh("");
}
if (cfile) {
# Print out the vop_F_vp_offsets structure. This all depends
# on naming conventions and nothing else.
printc("static int " name "_vp_offsets[] = {");
# as a side effect, figure out the releflags
releflags = "";
vpnum = 0;
for (i = 0; i < numargs; i++) {
if (types[i] == "struct vnode *") {
printc("\tVOPARG_OFFSETOF(struct " name \
"_args,a_" args[i] "),");
if (reles[i] == "WILLRELE") {
releflags = releflags \
"|VDESC_VP" vpnum "_WILLRELE";
}
vpnum++;
}
}
sub(/^\|/, "", releflags);
printc("\tVDESC_NO_OFFSET");
printc("};");
printc("\n");
printc("SDT_PROBE_DEFINE2(vfs, vop, " name ", entry, entry, \"struct vnode *\", \"struct " name "_args *\");\n");
printc("SDT_PROBE_DEFINE3(vfs, vop, " name ", return, return, \"struct vnode *\", \"struct " name "_args *\", \"int\");\n");
# Print out function.
printc("\nint\n" uname "_AP(struct " name "_args *a)");
printc("{");
printc("");
printc("\treturn(" uname "_APV(a->a_" args[0] "->v_op, a));");
printc("}");
printc("\nint\n" uname "_APV(struct vop_vector *vop, struct " name "_args *a)");
printc("{");
printc("\tint rc;");
printc("");
printc("\tVNASSERT(a->a_gen.a_desc == &" name "_desc, a->a_" args[0]",");
printc("\t (\"Wrong a_desc in " name "(%p, %p)\", a->a_" args[0]", a));");
printc("\twhile(vop != NULL && \\");
printc("\t vop->"name" == NULL && vop->vop_bypass == NULL)")
printc("\t\tvop = vop->vop_default;")
printc("\tVNASSERT(vop != NULL, a->a_" args[0]", (\"No "name"(%p, %p)\", a->a_" args[0]", a));")
printc("\tSDT_PROBE(vfs, vop, " name ", entry, a->a_" args[0] ", a, 0, 0, 0);\n");
for (i = 0; i < numargs; ++i)
add_debug_code(name, args[i], "Entry", "\t");
printc("\tKTR_START" ctrstr);
add_pre(name);
printc("\tVFS_PROLOGUE(a->a_" args[0]"->v_mount);")
printc("\tif (vop->"name" != NULL)")
printc("\t\trc = vop->"name"(a);")
printc("\telse")
printc("\t\trc = vop->vop_bypass(&a->a_gen);")
printc("\tVFS_EPILOGUE(a->a_" args[0]"->v_mount);")
printc("\tSDT_PROBE(vfs, vop, " name ", return, a->a_" args[0] ", a, rc, 0, 0);\n");
printc("\tif (rc == 0) {");
for (i = 0; i < numargs; ++i)
add_debug_code(name, args[i], "OK", "\t\t");
printc("\t} else {");
for (i = 0; i < numargs; ++i)
add_debug_code(name, args[i], "Error", "\t\t");
printc("\t}");
add_post(name);
printc("\tKTR_STOP" ctrstr);
printc("\treturn (rc);");
printc("}\n");
# Print out the vnodeop_desc structure.
printc("struct vnodeop_desc " name "_desc = {");
# printable name
printc("\t\"" name "\",");
# flags
vppwillrele = "";
for (i = 0; i < numargs; i++) {
if (types[i] == "struct vnode **" && \
reles[i] == "WILLRELE") {
vppwillrele = "|VDESC_VPP_WILLRELE";
}
}
if (!releflags)
releflags = "0";
printc("\t" releflags vppwillrele ",");
# function to call
printc("\t(vop_bypass_t *)" uname "_AP,");
# vp offsets
printc("\t" name "_vp_offsets,");
# vpp (if any)
printc("\t" find_arg_with_type("struct vnode **") ",");
# cred (if any)
printc("\t" find_arg_with_type("struct ucred *") ",");
# thread (if any)
printc("\t" find_arg_with_type("struct thread *") ",");
# componentname
printc("\t" find_arg_with_type("struct componentname *") ",");
# transport layer information
printc("};\n");
}
}
if (pfile)
printp("};")
if (hfile)
close(hfile);
if (cfile)
close(cfile);
if (pfile)
close(pfile);
close(srcfile);
exit 0;
}