Add '--with-spl-timeout' option

When checking for the SPL Module.symvers file, a timeout can now be
passed in which will pause the configure step while it waits for this
file to be generated. By default, the configure behavior is unchanged as
a timeout of 0 is used. If a positive number of seconds is passed,
configure will wait that number of seconds for the Module.symvers file
before moving on.

The main motivation for this change was to support parallel execution of
'./configure && make' for the SPL and ZFS packages in preparation of
supporting DKMS based packages.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

config/kernel.m4

@@ -218,24 +218,45 @@ AC_DEFUN([ZFS_AC_KERNEL], [
 dnl #
 dnl # Detect name used for the additional SPL Module.symvers file.  If one
 dnl # does not exist this is likely because the SPL has been configured
-dnl # but not built.  To allow recursive builds a good guess is made as to
-dnl # what this file will be named based on what it is named in the kernel
-dnl # build products.  This file will first be used at link time so if
-dnl # the guess is wrong the build will fail then.  This unfortunately
-dnl # means the ZFS package does not contain a reliable mechanism to
-dnl # detect symbols exported by the SPL at configure time.
+dnl # but not built.  The '--with-spl-timeout' option can be passed
+dnl # to pause here, waiting for the file to appear from a concurrently
+dnl # building SPL package.  If the file does not appear in time, a good
+dnl # guess is made as to what this file will be named based on what it
+dnl # is named in the kernel build products.  This file will first be
+dnl # used at link time so if the guess is wrong the build will fail
+dnl # then.  This unfortunately means the ZFS package does not contain a
+dnl # reliable mechanism to detect symbols exported by the SPL at
+dnl # configure time.
 dnl #
 AC_DEFUN([ZFS_AC_SPL_MODULE_SYMVERS], [
+	AC_ARG_WITH([spl-timeout],
+		AS_HELP_STRING([--with-spl-timeout=SECS],
+		[Wait SECS for symvers file to appear  @<:@default=0@:>@]),
+		[timeout="$withval"], [timeout=0])
+
 	AC_MSG_CHECKING([spl file name for module symbols])
-	AS_IF([test -r $SPL_OBJ/Module.symvers], [
-		SPL_SYMBOLS=Module.symvers
-	], [test -r $SPL_OBJ/Modules.symvers], [
-		SPL_SYMBOLS=Modules.symvers
-	], [test -r $SPL_OBJ/module/Module.symvers], [
-		SPL_SYMBOLS=Module.symvers
-	], [test -r $SPL_OBJ/module/Modules.symvers], [
-		SPL_SYMBOLS=Modules.symvers
-	], [
+	SPL_SYMBOLS=NONE
+
+	while true; do
+		AS_IF([test -r $SPL_OBJ/Module.symvers], [
+			SPL_SYMBOLS=Module.symvers
+		], [test -r $SPL_OBJ/Modules.symvers], [
+			SPL_SYMBOLS=Modules.symvers
+		], [test -r $SPL_OBJ/module/Module.symvers], [
+			SPL_SYMBOLS=Module.symvers
+		], [test -r $SPL_OBJ/module/Modules.symvers], [
+			SPL_SYMBOLS=Modules.symvers
+		])
+
+		AS_IF([test $SPL_SYMBOLS != NONE -o $timeout -le 0], [
+			break;
+		], [
+			sleep 1
+			timeout=$((timeout-1))
+		])
+	done
+
+	AS_IF([test "$SPL_SYMBOLS" = NONE], [
 		SPL_SYMBOLS=$LINUX_SYMBOLS
 	])
 

configure

@@ -986,6 +986,7 @@ with_linux
 with_linux_obj
 with_spl
 with_spl_obj
+with_spl_timeout
 with_udevdir
 with_udevruledir
 with_blkid
@@ -1660,6 +1661,7 @@ Optional Packages:
   --with-linux-obj=PATH   Path to kernel build objects
   --with-spl=PATH         Path to spl source
   --with-spl-obj=PATH     Path to spl build objects
+  --with-spl-timeout=SECS Wait SECS for symvers file to appear [default=0]
   --with-udevdir=DIR      install udev helpers [EPREFIX/lib/udev]
   --with-udevruledir=DIR  install udev rules [UDEVDIR/rules.d]
   --with-blkid            support blkid caching [default=check]
@@ -4842,13 +4844,13 @@ if test "${lt_cv_nm_interface+set}" = set; then
 else
   lt_cv_nm_interface="BSD nm"
   echo "int some_variable = 0;" > conftest.$ac_ext
-  (eval echo "\"\$as_me:4845: $ac_compile\"" >&5)
+  (eval echo "\"\$as_me:4847: $ac_compile\"" >&5)
   (eval "$ac_compile" 2>conftest.err)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:4848: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
+  (eval echo "\"\$as_me:4850: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
   (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:4851: output\"" >&5)
+  (eval echo "\"\$as_me:4853: output\"" >&5)
   cat conftest.out >&5
   if $GREP 'External.*some_variable' conftest.out > /dev/null; then
     lt_cv_nm_interface="MS dumpbin"
@@ -6054,7 +6056,7 @@ ia64-*-hpux*)
   ;;
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 6057 "configure"' > conftest.$ac_ext
+  echo '#line 6059 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -7907,11 +7909,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7910: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7912: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:7914: \$? = $ac_status" >&5
+   echo "$as_me:7916: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -8246,11 +8248,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:8249: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:8251: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:8253: \$? = $ac_status" >&5
+   echo "$as_me:8255: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -8351,11 +8353,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:8354: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:8356: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:8358: \$? = $ac_status" >&5
+   echo "$as_me:8360: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -8406,11 +8408,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:8409: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:8411: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:8413: \$? = $ac_status" >&5
+   echo "$as_me:8415: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -11209,7 +11211,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11212 "configure"
+#line 11214 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11305,7 +11307,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11308 "configure"
+#line 11310 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12384,26 +12386,54 @@ $as_echo "$splsrcver" >&6; }
 
 
 
+
+# Check whether --with-spl-timeout was given.
+if test "${with_spl_timeout+set}" = set; then
+  withval=$with_spl_timeout; timeout="$withval"
+else
+  timeout=0
+fi
+
+
 	{ $as_echo "$as_me:$LINENO: checking spl file name for module symbols" >&5
 $as_echo_n "checking spl file name for module symbols... " >&6; }
-	if test -r $SPL_OBJ/Module.symvers; then
+	SPL_SYMBOLS=NONE
 
-		SPL_SYMBOLS=Module.symvers
+	while true; do
+		if test -r $SPL_OBJ/Module.symvers; then
+
+			SPL_SYMBOLS=Module.symvers
 
 elif test -r $SPL_OBJ/Modules.symvers; then
 
-		SPL_SYMBOLS=Modules.symvers
+			SPL_SYMBOLS=Modules.symvers
 
 elif test -r $SPL_OBJ/module/Module.symvers; then
 
-		SPL_SYMBOLS=Module.symvers
+			SPL_SYMBOLS=Module.symvers
 
 elif test -r $SPL_OBJ/module/Modules.symvers; then
 
-		SPL_SYMBOLS=Modules.symvers
+			SPL_SYMBOLS=Modules.symvers
+
+fi
+
+
+		if test $SPL_SYMBOLS != NONE -o $timeout -le 0; then
+
+			break;
 
 else
 
+			sleep 1
+			timeout=$((timeout-1))
+
+fi
+
+	done
+
+	if test "$SPL_SYMBOLS" = NONE; then
+
 		SPL_SYMBOLS=$LINUX_SYMBOLS
 
 fi
@@ -19957,26 +19987,54 @@ $as_echo "$splsrcver" >&6; }
 
 
 
+
+# Check whether --with-spl-timeout was given.
+if test "${with_spl_timeout+set}" = set; then
+  withval=$with_spl_timeout; timeout="$withval"
+else
+  timeout=0
+fi
+
+
 	{ $as_echo "$as_me:$LINENO: checking spl file name for module symbols" >&5
 $as_echo_n "checking spl file name for module symbols... " >&6; }
-	if test -r $SPL_OBJ/Module.symvers; then
+	SPL_SYMBOLS=NONE
 
-		SPL_SYMBOLS=Module.symvers
+	while true; do
+		if test -r $SPL_OBJ/Module.symvers; then
+
+			SPL_SYMBOLS=Module.symvers
 
 elif test -r $SPL_OBJ/Modules.symvers; then
 
-		SPL_SYMBOLS=Modules.symvers
+			SPL_SYMBOLS=Modules.symvers
 
 elif test -r $SPL_OBJ/module/Module.symvers; then
 
-		SPL_SYMBOLS=Module.symvers
+			SPL_SYMBOLS=Module.symvers
 
 elif test -r $SPL_OBJ/module/Modules.symvers; then
 
-		SPL_SYMBOLS=Modules.symvers
+			SPL_SYMBOLS=Modules.symvers
+
+fi
+
+
+		if test $SPL_SYMBOLS != NONE -o $timeout -le 0; then
+
+			break;
 
 else
 
+			sleep 1
+			timeout=$((timeout-1))
+
+fi
+
+	done
+
+	if test "$SPL_SYMBOLS" = NONE; then
+
 		SPL_SYMBOLS=$LINUX_SYMBOLS
 
 fi