[pve-devel] [PATCH common v3 1/2] sysfstools: file_write: extend with logging and ignore list

[Dominik Csapak]

the actual error and path is useful to know when trying to debug or
figure out what did not work, so warn here if there was an error.

Now also takes an optional error list that can be ignored. If
encountering such an error, returns success instead of failure.

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
changes from v2:
* enhance comment
* improve commit message
* shorten return statement
* remove indentation by default initializing $ignore_list to []

 src/PVE/SysFSTools.pm | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/PVE/SysFSTools.pm b/src/PVE/SysFSTools.pm
index 0bde6d7..0aeff5f 100644
--- a/src/PVE/SysFSTools.pm
+++ b/src/PVE/SysFSTools.pm
@@ -211,17 +211,28 @@ sub check_iommu_support{
     return PVE::Tools::dir_glob_regex('/sys/class/iommu/', "[^\.].*");
 }
 
+# writes $buf into $filename, returns false and warns on errors not listed in the optional $ignore_list
+# error to ignore come from the POSIX module e.g. 'EEXIST'
 sub file_write {
-    my ($filename, $buf) = @_;
+    my ($filename, $buf, $ignore_list) = @_;
+    $ignore_list //= [];
 
     my $fh = IO::File->new($filename, "w");
     return undef if !$fh;
 
-    my $res = defined(syswrite($fh, $buf)) ? 1 : 0;
-
+    my $res = syswrite($fh, $buf);
     $fh->close();
 
-    return $res;
+    if (defined($res)) {
+	return 1;
+    } elsif (my $err = $!) {
+	for my $to_ignore ($ignore_list->@*) {
+	    return 1 if $err == $to_ignore;
+	}
+	warn "error writing '$buf' to '$filename': $err\n";
+    }
+
+    return 0;
 }
 
 sub pci_device_info {
-- 
2.39.5