Revision a742994aa2e271eb8cd8e043d276515ec858ed73 authored by Filipe Manana on 13 February 2015, 16:56:14 UTC, committed by Chris Mason on 14 February 2015, 16:22:49 UTC
If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
1 parent 1a4bcf4
streamline_config.pl
#!/usr/bin/perl -w
#
# Copyright 2005-2009 - Steven Rostedt
# Licensed under the terms of the GNU GPL License version 2
#
# It's simple enough to figure out how this works.
# If not, then you can ask me at stripconfig@goodmis.org
#
# What it does?
#
# If you have installed a Linux kernel from a distribution
# that turns on way too many modules than you need, and
# you only want the modules you use, then this program
# is perfect for you.
#
# It gives you the ability to turn off all the modules that are
# not loaded on your system.
#
# Howto:
#
# 1. Boot up the kernel that you want to stream line the config on.
# 2. Change directory to the directory holding the source of the
# kernel that you just booted.
# 3. Copy the configuraton file to this directory as .config
# 4. Have all your devices that you need modules for connected and
# operational (make sure that their corresponding modules are loaded)
# 5. Run this script redirecting the output to some other file
# like config_strip.
# 6. Back up your old config (if you want too).
# 7. copy the config_strip file to .config
# 8. Run "make oldconfig"
#
# Now your kernel is ready to be built with only the modules that
# are loaded.
#
# Here's what I did with my Debian distribution.
#
# cd /usr/src/linux-2.6.10
# cp /boot/config-2.6.10-1-686-smp .config
# ~/bin/streamline_config > config_strip
# mv .config config_sav
# mv config_strip .config
# make oldconfig
#
use strict;
use Getopt::Long;
# set the environment variable LOCALMODCONFIG_DEBUG to get
# debug output.
my $debugprint = 0;
$debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG}));
sub dprint {
return if (!$debugprint);
print STDERR @_;
}
my $config = ".config";
my $uname = `uname -r`;
chomp $uname;
my @searchconfigs = (
{
"file" => ".config",
"exec" => "cat",
},
{
"file" => "/proc/config.gz",
"exec" => "zcat",
},
{
"file" => "/boot/config-$uname",
"exec" => "cat",
},
{
"file" => "/boot/vmlinuz-$uname",
"exec" => "scripts/extract-ikconfig",
"test" => "scripts/extract-ikconfig",
},
{
"file" => "vmlinux",
"exec" => "scripts/extract-ikconfig",
"test" => "scripts/extract-ikconfig",
},
{
"file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
"exec" => "scripts/extract-ikconfig",
"test" => "scripts/extract-ikconfig",
},
{
"file" => "kernel/configs.ko",
"exec" => "scripts/extract-ikconfig",
"test" => "scripts/extract-ikconfig",
},
{
"file" => "kernel/configs.o",
"exec" => "scripts/extract-ikconfig",
"test" => "scripts/extract-ikconfig",
},
);
sub read_config {
foreach my $conf (@searchconfigs) {
my $file = $conf->{"file"};
next if ( ! -f "$file");
if (defined($conf->{"test"})) {
`$conf->{"test"} $conf->{"file"} 2>/dev/null`;
next if ($?);
}
my $exec = $conf->{"exec"};
print STDERR "using config: '$file'\n";
open(my $infile, '-|', "$exec $file") || die "Failed to run $exec $file";
my @x = <$infile>;
close $infile;
return @x;
}
die "No config file found";
}
my @config_file = read_config;
# Parse options
my $localmodconfig = 0;
my $localyesconfig = 0;
GetOptions("localmodconfig" => \$localmodconfig,
"localyesconfig" => \$localyesconfig);
# Get the build source and top level Kconfig file (passed in)
my $ksource = ($ARGV[0] ? $ARGV[0] : '.');
my $kconfig = $ARGV[1];
my $lsmod_file = $ENV{'LSMOD'};
my @makefiles = `find $ksource -name Makefile 2>/dev/null`;
chomp @makefiles;
my %depends;
my %selects;
my %prompts;
my %objects;
my $var;
my $iflevel = 0;
my @ifdeps;
# prevent recursion
my %read_kconfigs;
sub read_kconfig {
my ($kconfig) = @_;
my $state = "NONE";
my $config;
my $cont = 0;
my $line;
my $source = "$ksource/$kconfig";
my $last_source = "";
# Check for any environment variables used
while ($source =~ /\$(\w+)/ && $last_source ne $source) {
my $env = $1;
$last_source = $source;
$source =~ s/\$$env/$ENV{$env}/;
}
open(my $kinfile, '<', $source) || die "Can't open $kconfig";
while (<$kinfile>) {
chomp;
# Make sure that lines ending with \ continue
if ($cont) {
$_ = $line . " " . $_;
}
if (s/\\$//) {
$cont = 1;
$line = $_;
next;
}
$cont = 0;
# collect any Kconfig sources
if (/^source\s*"(.*)"/) {
my $kconfig = $1;
# prevent reading twice.
if (!defined($read_kconfigs{$kconfig})) {
$read_kconfigs{$kconfig} = 1;
read_kconfig($kconfig);
}
next;
}
# configs found
if (/^\s*(menu)?config\s+(\S+)\s*$/) {
$state = "NEW";
$config = $2;
# Add depends for 'if' nesting
for (my $i = 0; $i < $iflevel; $i++) {
if ($i) {
$depends{$config} .= " " . $ifdeps[$i];
} else {
$depends{$config} = $ifdeps[$i];
}
$state = "DEP";
}
# collect the depends for the config
} elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
$state = "DEP";
$depends{$config} = $1;
} elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
$depends{$config} .= " " . $1;
} elsif ($state eq "DEP" && /^\s*def(_(bool|tristate)|ault)\s+(\S.*)$/) {
my $dep = $3;
if ($dep !~ /^\s*(y|m|n)\s*$/) {
$dep =~ s/.*\sif\s+//;
$depends{$config} .= " " . $dep;
dprint "Added default depends $dep to $config\n";
}
# Get the configs that select this config
} elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
my $conf = $1;
if (defined($selects{$conf})) {
$selects{$conf} .= " " . $config;
} else {
$selects{$conf} = $config;
}
# configs without prompts must be selected
} elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
# note if the config has a prompt
$prompts{$config} = 1;
# Check for if statements
} elsif (/^if\s+(.*\S)\s*$/) {
my $deps = $1;
# remove beginning and ending non text
$deps =~ s/^[^a-zA-Z0-9_]*//;
$deps =~ s/[^a-zA-Z0-9_]*$//;
my @deps = split /[^a-zA-Z0-9_]+/, $deps;
$ifdeps[$iflevel++] = join ':', @deps;
} elsif (/^endif/) {
$iflevel-- if ($iflevel);
# stop on "help"
} elsif (/^\s*help\s*$/) {
$state = "NONE";
}
}
close($kinfile);
}
if ($kconfig) {
read_kconfig($kconfig);
}
# Makefiles can use variables to define their dependencies
sub convert_vars {
my ($line, %vars) = @_;
my $process = "";
while ($line =~ s/^(.*?)(\$\((.*?)\))//) {
my $start = $1;
my $variable = $2;
my $var = $3;
if (defined($vars{$var})) {
$process .= $start . $vars{$var};
} else {
$process .= $start . $variable;
}
}
$process .= $line;
return $process;
}
# Read all Makefiles to map the configs to the objects
foreach my $makefile (@makefiles) {
my $line = "";
my %make_vars;
open(my $infile, '<', $makefile) || die "Can't open $makefile";
while (<$infile>) {
# if this line ends with a backslash, continue
chomp;
if (/^(.*)\\$/) {
$line .= $1;
next;
}
$line .= $_;
$_ = $line;
$line = "";
my $objs;
# Convert variables in a line (could define configs)
$_ = convert_vars($_, %make_vars);
# collect objects after obj-$(CONFIG_FOO_BAR)
if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
$var = $1;
$objs = $2;
# check if variables are set
} elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) {
$make_vars{$1} = $2;
}
if (defined($objs)) {
foreach my $obj (split /\s+/,$objs) {
$obj =~ s/-/_/g;
if ($obj =~ /(.*)\.o$/) {
# Objects may be enabled by more than one config.
# Store configs in an array.
my @arr;
if (defined($objects{$1})) {
@arr = @{$objects{$1}};
}
$arr[$#arr+1] = $var;
# The objects have a hash mapping to a reference
# of an array of configs.
$objects{$1} = \@arr;
}
}
}
}
close($infile);
}
my %modules;
my $linfile;
if (defined($lsmod_file)) {
if ( ! -f $lsmod_file) {
if ( -f $ENV{'objtree'}."/".$lsmod_file) {
$lsmod_file = $ENV{'objtree'}."/".$lsmod_file;
} else {
die "$lsmod_file not found";
}
}
my $otype = ( -x $lsmod_file) ? '-|' : '<';
open($linfile, $otype, $lsmod_file);
} else {
# see what modules are loaded on this system
my $lsmod;
foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
if ( -x "$dir/lsmod" ) {
$lsmod = "$dir/lsmod";
last;
}
}
if (!defined($lsmod)) {
# try just the path
$lsmod = "lsmod";
}
open($linfile, '-|', $lsmod) || die "Can not call lsmod with $lsmod";
}
while (<$linfile>) {
next if (/^Module/); # Skip the first line.
if (/^(\S+)/) {
$modules{$1} = 1;
}
}
close ($linfile);
# add to the configs hash all configs that are needed to enable
# a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
# where we know we need bar.o so we add FOO to the list.
my %configs;
foreach my $module (keys(%modules)) {
if (defined($objects{$module})) {
my @arr = @{$objects{$module}};
foreach my $conf (@arr) {
$configs{$conf} = $module;
dprint "$conf added by direct ($module)\n";
if ($debugprint) {
my $c=$conf;
$c =~ s/^CONFIG_//;
if (defined($depends{$c})) {
dprint " deps = $depends{$c}\n";
} else {
dprint " no deps\n";
}
}
}
} else {
# Most likely, someone has a custom (binary?) module loaded.
print STDERR "$module config not found!!\n";
}
}
# Read the current config, and see what is enabled. We want to
# ignore configs that we would not enable anyway.
my %orig_configs;
my $valid = "A-Za-z_0-9";
foreach my $line (@config_file) {
$_ = $line;
if (/(CONFIG_[$valid]*)=(m|y)/) {
$orig_configs{$1} = $2;
}
}
my $repeat = 1;
my $depconfig;
#
# Note, we do not care about operands (like: &&, ||, !) we want to add any
# config that is in the depend list of another config. This script does
# not enable configs that are not already enabled. If we come across a
# config A that depends on !B, we can still add B to the list of depends
# to keep on. If A was on in the original config, B would not have been
# and B would not be turned on by this script.
#
sub parse_config_depends
{
my ($p) = @_;
while ($p =~ /[$valid]/) {
if ($p =~ /^[^$valid]*([$valid]+)/) {
my $conf = "CONFIG_" . $1;
$p =~ s/^[^$valid]*[$valid]+//;
# We only need to process if the depend config is a module
if (!defined($orig_configs{$conf}) || !$orig_configs{conf} eq "m") {
next;
}
if (!defined($configs{$conf})) {
# We must make sure that this config has its
# dependencies met.
$repeat = 1; # do again
dprint "$conf selected by depend $depconfig\n";
$configs{$conf} = 1;
}
} else {
die "this should never happen";
}
}
}
# Select is treated a bit differently than depends. We call this
# when a config has no prompt and requires another config to be
# selected. We use to just select all configs that selected this
# config, but found that that can balloon into enabling hundreds
# of configs that we do not care about.
#
# The idea is we look at all the configs that select it. If one
# is already in our list of configs to enable, then there's nothing
# else to do. If there isn't, we pick the first config that was
# enabled in the orignal config and use that.
sub parse_config_selects
{
my ($config, $p) = @_;
my $next_config;
while ($p =~ /[$valid]/) {
if ($p =~ /^[^$valid]*([$valid]+)/) {
my $conf = "CONFIG_" . $1;
$p =~ s/^[^$valid]*[$valid]+//;
# Make sure that this config exists in the current .config file
if (!defined($orig_configs{$conf})) {
dprint "$conf not set for $config select\n";
next;
}
# Check if something other than a module selects this config
if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
dprint "$conf (non module) selects config, we are good\n";
# we are good with this
return;
}
if (defined($configs{$conf})) {
dprint "$conf selects $config so we are good\n";
# A set config selects this config, we are good
return;
}
# Set this config to be selected
if (!defined($next_config)) {
$next_config = $conf;
}
} else {
die "this should never happen";
}
}
# If no possible config selected this, then something happened.
if (!defined($next_config)) {
print STDERR "WARNING: $config is required, but nothing in the\n";
print STDERR " current config selects it.\n";
return;
}
# If we are here, then we found no config that is set and
# selects this config. Repeat.
$repeat = 1;
# Make this config need to be selected
$configs{$next_config} = 1;
dprint "$next_config selected by select $config\n";
}
my %process_selects;
# loop through all configs, select their dependencies.
sub loop_depend {
$repeat = 1;
while ($repeat) {
$repeat = 0;
forloop:
foreach my $config (keys %configs) {
# If this config is not a module, we do not need to process it
if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
next forloop;
}
$config =~ s/^CONFIG_//;
$depconfig = $config;
if (defined($depends{$config})) {
# This config has dependencies. Make sure they are also included
parse_config_depends $depends{$config};
}
# If the config has no prompt, then we need to check if a config
# that is enabled selected it. Or if we need to enable one.
if (!defined($prompts{$config}) && defined($selects{$config})) {
$process_selects{$config} = 1;
}
}
}
}
sub loop_select {
foreach my $config (keys %process_selects) {
$config =~ s/^CONFIG_//;
dprint "Process select $config\n";
# config has no prompt and must be selected.
parse_config_selects $config, $selects{$config};
}
}
while ($repeat) {
# Get the first set of configs and their dependencies.
loop_depend;
$repeat = 0;
# Now we need to see if we have to check selects;
loop_select;
}
my %setconfigs;
# Finally, read the .config file and turn off any module enabled that
# we could not find a reason to keep enabled.
foreach my $line (@config_file) {
$_ = $line;
if (/CONFIG_IKCONFIG/) {
if (/# CONFIG_IKCONFIG is not set/) {
# enable IKCONFIG at least as a module
print "CONFIG_IKCONFIG=m\n";
# don't ask about PROC
print "# CONFIG_IKCONFIG_PROC is not set\n";
} else {
print;
}
next;
}
if (/^(CONFIG.*)=(m|y)/) {
if (defined($configs{$1})) {
if ($localyesconfig) {
$setconfigs{$1} = 'y';
print "$1=y\n";
next;
} else {
$setconfigs{$1} = $2;
}
} elsif ($2 eq "m") {
print "# $1 is not set\n";
next;
}
}
print;
}
# Integrity check, make sure all modules that we want enabled do
# indeed have their configs set.
loop:
foreach my $module (keys(%modules)) {
if (defined($objects{$module})) {
my @arr = @{$objects{$module}};
foreach my $conf (@arr) {
if (defined($setconfigs{$conf})) {
next loop;
}
}
print STDERR "module $module did not have configs";
foreach my $conf (@arr) {
print STDERR " " , $conf;
}
print STDERR "\n";
}
}
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