class_watchdog.go

Documentation: github.com/prometheus/procfs/sysfs

     1  // Copyright 2023 The Prometheus Authors
     2  // Licensed under the Apache License, Version 2.0 (the "License");
     3  // you may not use this file except in compliance with the License.
     4  // You may obtain a copy of the License at
     5  //
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  //go:build linux
    15  // +build linux
    16  
    17  package sysfs
    18  
    19  import (
    20  	"fmt"
    21  	"os"
    22  	"path/filepath"
    23  
    24  	"github.com/prometheus/procfs/internal/util"
    25  )
    26  
    27  const watchdogClassPath = "class/watchdog"
    28  
    29  // WatchdogStats contains info from files in /sys/class/watchdog for a single watchdog device.
    30  // https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-watchdog
    31  type WatchdogStats struct {
    32  	Name               string
    33  	Bootstatus         *int64  // /sys/class/watchdog/<Name>/bootstatus
    34  	Options            *string // /sys/class/watchdog/<Name>/options
    35  	FwVersion          *int64  // /sys/class/watchdog/<Name>/fw_version
    36  	Identity           *string // /sys/class/watchdog/<Name>/identity
    37  	Nowayout           *int64  // /sys/class/watchdog/<Name>/nowayout
    38  	State              *string // /sys/class/watchdog/<Name>/state
    39  	Status             *string // /sys/class/watchdog/<Name>/status
    40  	Timeleft           *int64  // /sys/class/watchdog/<Name>/timeleft
    41  	Timeout            *int64  // /sys/class/watchdog/<Name>/timeout
    42  	Pretimeout         *int64  // /sys/class/watchdog/<Name>/pretimeout
    43  	PretimeoutGovernor *string // /sys/class/watchdog/<Name>/pretimeout_governor
    44  	AccessCs0          *int64  // /sys/class/watchdog/<Name>/access_cs0
    45  }
    46  
    47  // WatchdogClass is a collection of statistics for every watchdog device in /sys/class/watchdog.
    48  //
    49  // The map keys are the names of the watchdog devices.
    50  type WatchdogClass map[string]WatchdogStats
    51  
    52  // WatchdogClass returns info for all watchdog devices read from /sys/class/watchdog.
    53  func (fs FS) WatchdogClass() (WatchdogClass, error) {
    54  	path := fs.sys.Path(watchdogClassPath)
    55  
    56  	dirs, err := os.ReadDir(path)
    57  	if err != nil {
    58  		return nil, fmt.Errorf("failed to list watchdog devices at %q: %w", path, err)
    59  	}
    60  
    61  	wds := make(WatchdogClass, len(dirs))
    62  	for _, d := range dirs {
    63  		stats, err := fs.parseWatchdog(d.Name())
    64  		if err != nil {
    65  			return nil, err
    66  		}
    67  
    68  		wds[stats.Name] = *stats
    69  	}
    70  
    71  	return wds, nil
    72  }
    73  
    74  func (fs FS) parseWatchdog(wdName string) (*WatchdogStats, error) {
    75  	path := fs.sys.Path(watchdogClassPath, wdName)
    76  	wd := WatchdogStats{Name: wdName}
    77  
    78  	for _, f := range [...]string{"bootstatus", "options", "fw_version", "identity", "nowayout", "state", "status", "timeleft", "timeout", "pretimeout", "pretimeout_governor", "access_cs0"} {
    79  		name := filepath.Join(path, f)
    80  		value, err := util.SysReadFile(name)
    81  		if err != nil {
    82  			if os.IsNotExist(err) {
    83  				continue
    84  			}
    85  			return nil, fmt.Errorf("failed to read file %q: %w", name, err)
    86  		}
    87  
    88  		vp := util.NewValueParser(value)
    89  
    90  		switch f {
    91  		case "bootstatus":
    92  			wd.Bootstatus = vp.PInt64()
    93  		case "options":
    94  			wd.Options = &value
    95  		case "fw_version":
    96  			wd.FwVersion = vp.PInt64()
    97  		case "identity":
    98  			wd.Identity = &value
    99  		case "nowayout":
   100  			wd.Nowayout = vp.PInt64()
   101  		case "state":
   102  			wd.State = &value
   103  		case "status":
   104  			wd.Status = &value
   105  		case "timeleft":
   106  			wd.Timeleft = vp.PInt64()
   107  		case "timeout":
   108  			wd.Timeout = vp.PInt64()
   109  		case "pretimeout":
   110  			wd.Pretimeout = vp.PInt64()
   111  		case "pretimeout_governor":
   112  			wd.PretimeoutGovernor = &value
   113  		case "access_cs0":
   114  			wd.AccessCs0 = vp.PInt64()
   115  		}
   116  
   117  		if err := vp.Err(); err != nil {
   118  			return nil, err
   119  		}
   120  	}
   121  
   122  	return &wd, nil
   123  }
   124
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