From 2b481b5477d3a95d0eab723c6639f7114e146ae1 Mon Sep 17 00:00:00 2001 From: Rob Norris Date: Tue, 12 Mar 2024 20:38:12 +1100 Subject: [PATCH] config/kernel: enforce kernel max version, with escape hatch It's possible for OpenZFS to build correctly against a newer kernel than it is supported for, but then not work correctly. This invariably results in disappointment, confusion and/or anger. Sometimes however we do actually want to compile against a newer kernel than is supported, usually when testing a pre-release kernel. Add the deliberately-verbose `--disable-supported-linux-version-check` option to disable this check. This is lots to type, and so hopefully can be taken as a very explicit signal that the user knows what they're doing. Finally, if an unsupported kernel is used and the option is used, a big warning message is displayed at the end of the configure run to really try and make the point. Signed-off-by: Rob Norris Sponsored-by: https://despairlabs.com/sponsor/ --- config/ax_compare_version.m4 | 177 +++++++++++++++++++++++++++++++++++ config/kernel.m4 | 59 +++++++++++- configure.ac | 2 + 3 files changed, 236 insertions(+), 2 deletions(-) create mode 100644 config/ax_compare_version.m4 diff --git a/config/ax_compare_version.m4 b/config/ax_compare_version.m4 new file mode 100644 index 000000000000..ffb4997e8b14 --- /dev/null +++ b/config/ax_compare_version.m4 @@ -0,0 +1,177 @@ +# =========================================================================== +# https://www.gnu.org/software/autoconf-archive/ax_compare_version.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_COMPARE_VERSION(VERSION_A, OP, VERSION_B, [ACTION-IF-TRUE], [ACTION-IF-FALSE]) +# +# DESCRIPTION +# +# This macro compares two version strings. Due to the various number of +# minor-version numbers that can exist, and the fact that string +# comparisons are not compatible with numeric comparisons, this is not +# necessarily trivial to do in a autoconf script. This macro makes doing +# these comparisons easy. +# +# The six basic comparisons are available, as well as checking equality +# limited to a certain number of minor-version levels. +# +# The operator OP determines what type of comparison to do, and can be one +# of: +# +# eq - equal (test A == B) +# ne - not equal (test A != B) +# le - less than or equal (test A <= B) +# ge - greater than or equal (test A >= B) +# lt - less than (test A < B) +# gt - greater than (test A > B) +# +# Additionally, the eq and ne operator can have a number after it to limit +# the test to that number of minor versions. +# +# eq0 - equal up to the length of the shorter version +# ne0 - not equal up to the length of the shorter version +# eqN - equal up to N sub-version levels +# neN - not equal up to N sub-version levels +# +# When the condition is true, shell commands ACTION-IF-TRUE are run, +# otherwise shell commands ACTION-IF-FALSE are run. The environment +# variable 'ax_compare_version' is always set to either 'true' or 'false' +# as well. +# +# Examples: +# +# AX_COMPARE_VERSION([3.15.7],[lt],[3.15.8]) +# AX_COMPARE_VERSION([3.15],[lt],[3.15.8]) +# +# would both be true. +# +# AX_COMPARE_VERSION([3.15.7],[eq],[3.15.8]) +# AX_COMPARE_VERSION([3.15],[gt],[3.15.8]) +# +# would both be false. +# +# AX_COMPARE_VERSION([3.15.7],[eq2],[3.15.8]) +# +# would be true because it is only comparing two minor versions. +# +# AX_COMPARE_VERSION([3.15.7],[eq0],[3.15]) +# +# would be true because it is only comparing the lesser number of minor +# versions of the two values. +# +# Note: The characters that separate the version numbers do not matter. An +# empty string is the same as version 0. OP is evaluated by autoconf, not +# configure, so must be a string, not a variable. +# +# The author would like to acknowledge Guido Draheim whose advice about +# the m4_case and m4_ifvaln functions make this macro only include the +# portions necessary to perform the specific comparison specified by the +# OP argument in the final configure script. +# +# LICENSE +# +# Copyright (c) 2008 Tim Toolan +# +# Copying and distribution of this file, with or without modification, are +# permitted in any medium without royalty provided the copyright notice +# and this notice are preserved. This file is offered as-is, without any +# warranty. + +#serial 13 + +dnl ######################################################################### +AC_DEFUN([AX_COMPARE_VERSION], [ + AC_REQUIRE([AC_PROG_AWK]) + + # Used to indicate true or false condition + ax_compare_version=false + + # Convert the two version strings to be compared into a format that + # allows a simple string comparison. The end result is that a version + # string of the form 1.12.5-r617 will be converted to the form + # 0001001200050617. In other words, each number is zero padded to four + # digits, and non digits are removed. + AS_VAR_PUSHDEF([A],[ax_compare_version_A]) + A=`echo "$1" | sed -e 's/\([[0-9]]*\)/Z\1Z/g' \ + -e 's/Z\([[0-9]]\)Z/Z0\1Z/g' \ + -e 's/Z\([[0-9]][[0-9]]\)Z/Z0\1Z/g' \ + -e 's/Z\([[0-9]][[0-9]][[0-9]]\)Z/Z0\1Z/g' \ + -e 's/[[^0-9]]//g'` + + AS_VAR_PUSHDEF([B],[ax_compare_version_B]) + B=`echo "$3" | sed -e 's/\([[0-9]]*\)/Z\1Z/g' \ + -e 's/Z\([[0-9]]\)Z/Z0\1Z/g' \ + -e 's/Z\([[0-9]][[0-9]]\)Z/Z0\1Z/g' \ + -e 's/Z\([[0-9]][[0-9]][[0-9]]\)Z/Z0\1Z/g' \ + -e 's/[[^0-9]]//g'` + + dnl # In the case of le, ge, lt, and gt, the strings are sorted as necessary + dnl # then the first line is used to determine if the condition is true. + dnl # The sed right after the echo is to remove any indented white space. + m4_case(m4_tolower($2), + [lt],[ + ax_compare_version=`echo "x$A +x$B" | sed 's/^ *//' | sort -r | sed "s/x${A}/false/;s/x${B}/true/;1q"` + ], + [gt],[ + ax_compare_version=`echo "x$A +x$B" | sed 's/^ *//' | sort | sed "s/x${A}/false/;s/x${B}/true/;1q"` + ], + [le],[ + ax_compare_version=`echo "x$A +x$B" | sed 's/^ *//' | sort | sed "s/x${A}/true/;s/x${B}/false/;1q"` + ], + [ge],[ + ax_compare_version=`echo "x$A +x$B" | sed 's/^ *//' | sort -r | sed "s/x${A}/true/;s/x${B}/false/;1q"` + ],[ + dnl Split the operator from the subversion count if present. + m4_bmatch(m4_substr($2,2), + [0],[ + # A count of zero means use the length of the shorter version. + # Determine the number of characters in A and B. + ax_compare_version_len_A=`echo "$A" | $AWK '{print(length)}'` + ax_compare_version_len_B=`echo "$B" | $AWK '{print(length)}'` + + # Set A to no more than B's length and B to no more than A's length. + A=`echo "$A" | sed "s/\(.\{$ax_compare_version_len_B\}\).*/\1/"` + B=`echo "$B" | sed "s/\(.\{$ax_compare_version_len_A\}\).*/\1/"` + ], + [[0-9]+],[ + # A count greater than zero means use only that many subversions + A=`echo "$A" | sed "s/\(\([[0-9]]\{4\}\)\{m4_substr($2,2)\}\).*/\1/"` + B=`echo "$B" | sed "s/\(\([[0-9]]\{4\}\)\{m4_substr($2,2)\}\).*/\1/"` + ], + [.+],[ + AC_WARNING( + [invalid OP numeric parameter: $2]) + ],[]) + + # Pad zeros at end of numbers to make same length. + ax_compare_version_tmp_A="$A`echo $B | sed 's/./0/g'`" + B="$B`echo $A | sed 's/./0/g'`" + A="$ax_compare_version_tmp_A" + + # Check for equality or inequality as necessary. + m4_case(m4_tolower(m4_substr($2,0,2)), + [eq],[ + test "x$A" = "x$B" && ax_compare_version=true + ], + [ne],[ + test "x$A" != "x$B" && ax_compare_version=true + ],[ + AC_WARNING([invalid OP parameter: $2]) + ]) + ]) + + AS_VAR_POPDEF([A])dnl + AS_VAR_POPDEF([B])dnl + + dnl # Execute ACTION-IF-TRUE / ACTION-IF-FALSE. + if test "$ax_compare_version" = "true" ; then + m4_ifvaln([$4],[$4],[:])dnl + m4_ifvaln([$5],[else $5])dnl + fi +]) dnl AX_COMPARE_VERSION diff --git a/config/kernel.m4 b/config/kernel.m4 index e3f8645774c5..a3f8efc48e88 100644 --- a/config/kernel.m4 +++ b/config/kernel.m4 @@ -497,10 +497,39 @@ AC_DEFUN([ZFS_AC_KERNEL], [ AC_MSG_RESULT([$kernsrcver]) - AS_VERSION_COMPARE([$kernsrcver], [$ZFS_META_KVER_MIN], [ - AC_MSG_ERROR([ + AC_ARG_ENABLE([supported-linux-version-check], + AS_HELP_STRING([--disable-supported-linux-version-check], + [Do not check if building against a supported Linux version])) + + AX_COMPARE_VERSION([$kernsrcver], [ge], [$ZFS_META_KVER_MIN], [ + kern_min_version_ok=yes + ], [ + kern_min_version_ok=no + ]) + + AX_COMPARE_VERSION([$kernsrcver], [ge], [$ZFS_META_KVER_MAX], [ + AX_COMPARE_VERSION([$kernsrcver], [eq2], [$ZFS_META_KVER_MAX], [ + kern_max_version_ok=yes + ], [ + kern_max_version_ok=no + ]) + ], [ + kern_max_version_ok=yes + ]) + + AS_IF([test "x$enable_supported_linux_version_check" != "xno"], [ + AS_IF([test "x$kern_min_version_ok" != "xyes"], [ + AC_MSG_ERROR([ *** Cannot build against kernel version $kernsrcver. *** The minimum supported kernel version is $ZFS_META_KVER_MIN. + ]) + ]) + + AS_IF([test "x$kern_max_version_ok" != "xyes"], [ + AC_MSG_ERROR([ + *** Cannot build against kernel version $kernsrcver. + *** The maximum supported kernel version is $ZFS_META_KVER_MAX. + ]) ]) ]) @@ -513,6 +542,32 @@ AC_DEFUN([ZFS_AC_KERNEL], [ AC_SUBST(LINUX_VERSION) ]) +AC_DEFUN([ZFS_AC_KERNEL_VERSION_WARNING], [ + AS_IF([test "x$enable_supported_linux_version_check" = "xno"], [ + AS_IF([test "x$kern_min_version_ok" != "xyes" || \ + test "x$kern_max_version_ok" != "xyes"], [ + AC_MSG_WARN([ + + You are building OpenZFS against Linux version $kernsrcver. + + This combination IS NOT SUPPORTED by the OpenZFS project. Even if it + appears to build and run correctly, there may be bugs that can cause + SERIOUS DATA LOSS. + + YOU HAVE BEEN WARNED! + + If you choose to continue, we'd appreciate if you could report your + results on the OpenZFS issue tracker at: + + https://github.com/openzfs/zfs/issues/new + + Your feedback will help us prepare a new OpenZFS release that supports + this version of Linux. + ]) + ]) + ]) +]) + dnl # dnl # Detect the QAT module to be built against, QAT provides hardware dnl # acceleration for data compression: diff --git a/configure.ac b/configure.ac index 2ce049c58219..9e043862ed1f 100644 --- a/configure.ac +++ b/configure.ac @@ -87,3 +87,5 @@ AC_CONFIG_FILES([ AC_OUTPUT + +ZFS_AC_KERNEL_VERSION_WARNING