From 934b4a08793c34f2b4146edd90a97438eada8bf1 Mon Sep 17 00:00:00 2001
From: Joshua Powers <powersj@fastmail.com>
Date: Thu, 25 Jul 2024 13:04:42 -0600
Subject: [PATCH] fix(inputs.diskio): Print warnings once, add details to
 messages (#15667)

---
 plugins/inputs/diskio/diskio.go       | 21 ++++++++++++++++-----
 plugins/inputs/diskio/diskio_linux.go |  4 ++--
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/plugins/inputs/diskio/diskio.go b/plugins/inputs/diskio/diskio.go
index 974cc82d1..009a0d39e 100644
--- a/plugins/inputs/diskio/diskio.go
+++ b/plugins/inputs/diskio/diskio.go
@@ -35,6 +35,8 @@ type DiskIO struct {
 	ps           system.PS
 	infoCache    map[string]diskInfoCache
 	deviceFilter filter.Filter
+	warnDiskName map[string]bool
+	warnDiskTags map[string]bool
 }
 
 func (*DiskIO) SampleConfig() string {
@@ -53,6 +55,8 @@ func (d *DiskIO) Init() error {
 	}
 
 	d.infoCache = make(map[string]diskInfoCache)
+	d.warnDiskName = make(map[string]bool)
+	d.warnDiskTags = make(map[string]bool)
 
 	return nil
 }
@@ -133,13 +137,17 @@ func (d *DiskIO) diskName(devName string) (string, []string) {
 	for i, devLink := range devLinks {
 		devLinks[i] = strings.TrimPrefix(devLink, "/dev/")
 	}
-
-	if len(d.NameTemplates) == 0 {
+	// Return error after attempting to process some of the devlinks.
+	// These could exist if we got further along the diskInfo call.
+	if err != nil {
+		if ok := d.warnDiskName[devName]; !ok {
+			d.warnDiskName[devName] = true
+			d.Log.Warnf("Unable to gather disk name for %q: %s", devName, err)
+		}
 		return devName, devLinks
 	}
 
-	if err != nil {
-		d.Log.Warnf("Error gathering disk info: %s", err)
+	if len(d.NameTemplates) == 0 {
 		return devName, devLinks
 	}
 
@@ -172,7 +180,10 @@ func (d *DiskIO) diskTags(devName string) map[string]string {
 
 	di, err := d.diskInfo(devName)
 	if err != nil {
-		d.Log.Warnf("Error gathering disk info: %s", err)
+		if ok := d.warnDiskTags[devName]; !ok {
+			d.warnDiskTags[devName] = true
+			d.Log.Warnf("Unable to gather disk tags for %q: %s", devName, err)
+		}
 		return nil
 	}
 
diff --git a/plugins/inputs/diskio/diskio_linux.go b/plugins/inputs/diskio/diskio_linux.go
index 6e6d4a37c..1c0db6146 100644
--- a/plugins/inputs/diskio/diskio_linux.go
+++ b/plugins/inputs/diskio/diskio_linux.go
@@ -25,7 +25,7 @@ func (d *DiskIO) diskInfo(devName string) (map[string]string, error) {
 	path := "/dev/" + devName
 	var stat unix.Stat_t
 	if err := unix.Stat(path, &stat); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error reading %s: %w", path, err)
 	}
 
 	// Check if we already got a cached and valid entry
@@ -49,7 +49,7 @@ func (d *DiskIO) diskInfo(devName string) (map[string]string, error) {
 			udevDataPath = "/dev/.udev/db/block:" + devName
 			if _, err := os.Stat(udevDataPath); err != nil {
 				// Giving up, cannot retrieve disk info
-				return nil, err
+				return nil, fmt.Errorf("error reading %s: %w", udevDataPath, err)
 			}
 		}
 	}