fscache.go

Documentation: github.com/prometheus/procfs

     1  // Copyright 2019 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  package procfs
    15  
    16  import (
    17  	"bufio"
    18  	"bytes"
    19  	"fmt"
    20  	"io"
    21  	"strconv"
    22  	"strings"
    23  
    24  	"github.com/prometheus/procfs/internal/util"
    25  )
    26  
    27  // Fscacheinfo represents fscache statistics.
    28  type Fscacheinfo struct {
    29  	// Number of index cookies allocated
    30  	IndexCookiesAllocated uint64
    31  	// data storage cookies allocated
    32  	DataStorageCookiesAllocated uint64
    33  	// Number of special cookies allocated
    34  	SpecialCookiesAllocated uint64
    35  	// Number of objects allocated
    36  	ObjectsAllocated uint64
    37  	// Number of object allocation failures
    38  	ObjectAllocationsFailure uint64
    39  	// Number of objects that reached the available state
    40  	ObjectsAvailable uint64
    41  	// Number of objects that reached the dead state
    42  	ObjectsDead uint64
    43  	// Number of objects that didn't have a coherency check
    44  	ObjectsWithoutCoherencyCheck uint64
    45  	// Number of objects that passed a coherency check
    46  	ObjectsWithCoherencyCheck uint64
    47  	// Number of objects that needed a coherency data update
    48  	ObjectsNeedCoherencyCheckUpdate uint64
    49  	// Number of objects that were declared obsolete
    50  	ObjectsDeclaredObsolete uint64
    51  	// Number of pages marked as being cached
    52  	PagesMarkedAsBeingCached uint64
    53  	// Number of uncache page requests seen
    54  	UncachePagesRequestSeen uint64
    55  	// Number of acquire cookie requests seen
    56  	AcquireCookiesRequestSeen uint64
    57  	// Number of acq reqs given a NULL parent
    58  	AcquireRequestsWithNullParent uint64
    59  	// Number of acq reqs rejected due to no cache available
    60  	AcquireRequestsRejectedNoCacheAvailable uint64
    61  	// Number of acq reqs succeeded
    62  	AcquireRequestsSucceeded uint64
    63  	// Number of acq reqs rejected due to error
    64  	AcquireRequestsRejectedDueToError uint64
    65  	// Number of acq reqs failed on ENOMEM
    66  	AcquireRequestsFailedDueToEnomem uint64
    67  	// Number of lookup calls made on cache backends
    68  	LookupsNumber uint64
    69  	// Number of negative lookups made
    70  	LookupsNegative uint64
    71  	// Number of positive lookups made
    72  	LookupsPositive uint64
    73  	// Number of objects created by lookup
    74  	ObjectsCreatedByLookup uint64
    75  	// Number of lookups timed out and requeued
    76  	LookupsTimedOutAndRequed uint64
    77  	InvalidationsNumber      uint64
    78  	InvalidationsRunning     uint64
    79  	// Number of update cookie requests seen
    80  	UpdateCookieRequestSeen uint64
    81  	// Number of upd reqs given a NULL parent
    82  	UpdateRequestsWithNullParent uint64
    83  	// Number of upd reqs granted CPU time
    84  	UpdateRequestsRunning uint64
    85  	// Number of relinquish cookie requests seen
    86  	RelinquishCookiesRequestSeen uint64
    87  	// Number of rlq reqs given a NULL parent
    88  	RelinquishCookiesWithNullParent uint64
    89  	// Number of rlq reqs waited on completion of creation
    90  	RelinquishRequestsWaitingCompleteCreation uint64
    91  	// Relinqs rtr
    92  	RelinquishRetries uint64
    93  	// Number of attribute changed requests seen
    94  	AttributeChangedRequestsSeen uint64
    95  	// Number of attr changed requests queued
    96  	AttributeChangedRequestsQueued uint64
    97  	// Number of attr changed rejected -ENOBUFS
    98  	AttributeChangedRejectDueToEnobufs uint64
    99  	// Number of attr changed failed -ENOMEM
   100  	AttributeChangedFailedDueToEnomem uint64
   101  	// Number of attr changed ops given CPU time
   102  	AttributeChangedOps uint64
   103  	// Number of allocation requests seen
   104  	AllocationRequestsSeen uint64
   105  	// Number of successful alloc reqs
   106  	AllocationOkRequests uint64
   107  	// Number of alloc reqs that waited on lookup completion
   108  	AllocationWaitingOnLookup uint64
   109  	// Number of alloc reqs rejected -ENOBUFS
   110  	AllocationsRejectedDueToEnobufs uint64
   111  	// Number of alloc reqs aborted -ERESTARTSYS
   112  	AllocationsAbortedDueToErestartsys uint64
   113  	// Number of alloc reqs submitted
   114  	AllocationOperationsSubmitted uint64
   115  	// Number of alloc reqs waited for CPU time
   116  	AllocationsWaitedForCPU uint64
   117  	// Number of alloc reqs aborted due to object death
   118  	AllocationsAbortedDueToObjectDeath uint64
   119  	// Number of retrieval (read) requests seen
   120  	RetrievalsReadRequests uint64
   121  	// Number of successful retr reqs
   122  	RetrievalsOk uint64
   123  	// Number of retr reqs that waited on lookup completion
   124  	RetrievalsWaitingLookupCompletion uint64
   125  	// Number of retr reqs returned -ENODATA
   126  	RetrievalsReturnedEnodata uint64
   127  	// Number of retr reqs rejected -ENOBUFS
   128  	RetrievalsRejectedDueToEnobufs uint64
   129  	// Number of retr reqs aborted -ERESTARTSYS
   130  	RetrievalsAbortedDueToErestartsys uint64
   131  	// Number of retr reqs failed -ENOMEM
   132  	RetrievalsFailedDueToEnomem uint64
   133  	// Number of retr reqs submitted
   134  	RetrievalsRequests uint64
   135  	// Number of retr reqs waited for CPU time
   136  	RetrievalsWaitingCPU uint64
   137  	// Number of retr reqs aborted due to object death
   138  	RetrievalsAbortedDueToObjectDeath uint64
   139  	// Number of storage (write) requests seen
   140  	StoreWriteRequests uint64
   141  	// Number of successful store reqs
   142  	StoreSuccessfulRequests uint64
   143  	// Number of store reqs on a page already pending storage
   144  	StoreRequestsOnPendingStorage uint64
   145  	// Number of store reqs rejected -ENOBUFS
   146  	StoreRequestsRejectedDueToEnobufs uint64
   147  	// Number of store reqs failed -ENOMEM
   148  	StoreRequestsFailedDueToEnomem uint64
   149  	// Number of store reqs submitted
   150  	StoreRequestsSubmitted uint64
   151  	// Number of store reqs granted CPU time
   152  	StoreRequestsRunning uint64
   153  	// Number of pages given store req processing time
   154  	StorePagesWithRequestsProcessing uint64
   155  	// Number of store reqs deleted from tracking tree
   156  	StoreRequestsDeleted uint64
   157  	// Number of store reqs over store limit
   158  	StoreRequestsOverStoreLimit uint64
   159  	// Number of release reqs against pages with no pending store
   160  	ReleaseRequestsAgainstPagesWithNoPendingStorage uint64
   161  	// Number of release reqs against pages stored by time lock granted
   162  	ReleaseRequestsAgainstPagesStoredByTimeLockGranted uint64
   163  	// Number of release reqs ignored due to in-progress store
   164  	ReleaseRequestsIgnoredDueToInProgressStore uint64
   165  	// Number of page stores cancelled due to release req
   166  	PageStoresCancelledByReleaseRequests uint64
   167  	VmscanWaiting                        uint64
   168  	// Number of times async ops added to pending queues
   169  	OpsPending uint64
   170  	// Number of times async ops given CPU time
   171  	OpsRunning uint64
   172  	// Number of times async ops queued for processing
   173  	OpsEnqueued uint64
   174  	// Number of async ops cancelled
   175  	OpsCancelled uint64
   176  	// Number of async ops rejected due to object lookup/create failure
   177  	OpsRejected uint64
   178  	// Number of async ops initialised
   179  	OpsInitialised uint64
   180  	// Number of async ops queued for deferred release
   181  	OpsDeferred uint64
   182  	// Number of async ops released (should equal ini=N when idle)
   183  	OpsReleased uint64
   184  	// Number of deferred-release async ops garbage collected
   185  	OpsGarbageCollected uint64
   186  	// Number of in-progress alloc_object() cache ops
   187  	CacheopAllocationsinProgress uint64
   188  	// Number of in-progress lookup_object() cache ops
   189  	CacheopLookupObjectInProgress uint64
   190  	// Number of in-progress lookup_complete() cache ops
   191  	CacheopLookupCompleteInPorgress uint64
   192  	// Number of in-progress grab_object() cache ops
   193  	CacheopGrabObjectInProgress uint64
   194  	CacheopInvalidations        uint64
   195  	// Number of in-progress update_object() cache ops
   196  	CacheopUpdateObjectInProgress uint64
   197  	// Number of in-progress drop_object() cache ops
   198  	CacheopDropObjectInProgress uint64
   199  	// Number of in-progress put_object() cache ops
   200  	CacheopPutObjectInProgress uint64
   201  	// Number of in-progress attr_changed() cache ops
   202  	CacheopAttributeChangeInProgress uint64
   203  	// Number of in-progress sync_cache() cache ops
   204  	CacheopSyncCacheInProgress uint64
   205  	// Number of in-progress read_or_alloc_page() cache ops
   206  	CacheopReadOrAllocPageInProgress uint64
   207  	// Number of in-progress read_or_alloc_pages() cache ops
   208  	CacheopReadOrAllocPagesInProgress uint64
   209  	// Number of in-progress allocate_page() cache ops
   210  	CacheopAllocatePageInProgress uint64
   211  	// Number of in-progress allocate_pages() cache ops
   212  	CacheopAllocatePagesInProgress uint64
   213  	// Number of in-progress write_page() cache ops
   214  	CacheopWritePagesInProgress uint64
   215  	// Number of in-progress uncache_page() cache ops
   216  	CacheopUncachePagesInProgress uint64
   217  	// Number of in-progress dissociate_pages() cache ops
   218  	CacheopDissociatePagesInProgress uint64
   219  	// Number of object lookups/creations rejected due to lack of space
   220  	CacheevLookupsAndCreationsRejectedLackSpace uint64
   221  	// Number of stale objects deleted
   222  	CacheevStaleObjectsDeleted uint64
   223  	// Number of objects retired when relinquished
   224  	CacheevRetiredWhenReliquished uint64
   225  	// Number of objects culled
   226  	CacheevObjectsCulled uint64
   227  }
   228  
   229  // Fscacheinfo returns information about current fscache statistics.
   230  // See https://www.kernel.org/doc/Documentation/filesystems/caching/fscache.txt
   231  func (fs FS) Fscacheinfo() (Fscacheinfo, error) {
   232  	b, err := util.ReadFileNoStat(fs.proc.Path("fs/fscache/stats"))
   233  	if err != nil {
   234  		return Fscacheinfo{}, err
   235  	}
   236  
   237  	m, err := parseFscacheinfo(bytes.NewReader(b))
   238  	if err != nil {
   239  		return Fscacheinfo{}, fmt.Errorf("%s: Cannot parse %v: %w", ErrFileParse, m, err)
   240  	}
   241  
   242  	return *m, nil
   243  }
   244  
   245  func setFSCacheFields(fields []string, setFields ...*uint64) error {
   246  	var err error
   247  	if len(fields) < len(setFields) {
   248  		return fmt.Errorf("%s: Expected %d, but got %d: %w", ErrFileParse, len(setFields), len(fields), err)
   249  	}
   250  
   251  	for i := range setFields {
   252  		*setFields[i], err = strconv.ParseUint(strings.Split(fields[i], "=")[1], 0, 64)
   253  		if err != nil {
   254  			return err
   255  		}
   256  	}
   257  	return nil
   258  }
   259  
   260  func parseFscacheinfo(r io.Reader) (*Fscacheinfo, error) {
   261  	var m Fscacheinfo
   262  	s := bufio.NewScanner(r)
   263  	for s.Scan() {
   264  		fields := strings.Fields(s.Text())
   265  		if len(fields) < 2 {
   266  			return nil, fmt.Errorf("%w: malformed Fscacheinfo line: %q", ErrFileParse, s.Text())
   267  		}
   268  
   269  		switch fields[0] {
   270  		case "Cookies:":
   271  			err := setFSCacheFields(fields[1:], &m.IndexCookiesAllocated, &m.DataStorageCookiesAllocated,
   272  				&m.SpecialCookiesAllocated)
   273  			if err != nil {
   274  				return &m, err
   275  			}
   276  		case "Objects:":
   277  			err := setFSCacheFields(fields[1:], &m.ObjectsAllocated, &m.ObjectAllocationsFailure,
   278  				&m.ObjectsAvailable, &m.ObjectsDead)
   279  			if err != nil {
   280  				return &m, err
   281  			}
   282  		case "ChkAux":
   283  			err := setFSCacheFields(fields[2:], &m.ObjectsWithoutCoherencyCheck, &m.ObjectsWithCoherencyCheck,
   284  				&m.ObjectsNeedCoherencyCheckUpdate, &m.ObjectsDeclaredObsolete)
   285  			if err != nil {
   286  				return &m, err
   287  			}
   288  		case "Pages":
   289  			err := setFSCacheFields(fields[2:], &m.PagesMarkedAsBeingCached, &m.UncachePagesRequestSeen)
   290  			if err != nil {
   291  				return &m, err
   292  			}
   293  		case "Acquire:":
   294  			err := setFSCacheFields(fields[1:], &m.AcquireCookiesRequestSeen, &m.AcquireRequestsWithNullParent,
   295  				&m.AcquireRequestsRejectedNoCacheAvailable, &m.AcquireRequestsSucceeded, &m.AcquireRequestsRejectedDueToError,
   296  				&m.AcquireRequestsFailedDueToEnomem)
   297  			if err != nil {
   298  				return &m, err
   299  			}
   300  		case "Lookups:":
   301  			err := setFSCacheFields(fields[1:], &m.LookupsNumber, &m.LookupsNegative, &m.LookupsPositive,
   302  				&m.ObjectsCreatedByLookup, &m.LookupsTimedOutAndRequed)
   303  			if err != nil {
   304  				return &m, err
   305  			}
   306  		case "Invals":
   307  			err := setFSCacheFields(fields[2:], &m.InvalidationsNumber, &m.InvalidationsRunning)
   308  			if err != nil {
   309  				return &m, err
   310  			}
   311  		case "Updates:":
   312  			err := setFSCacheFields(fields[1:], &m.UpdateCookieRequestSeen, &m.UpdateRequestsWithNullParent,
   313  				&m.UpdateRequestsRunning)
   314  			if err != nil {
   315  				return &m, err
   316  			}
   317  		case "Relinqs:":
   318  			err := setFSCacheFields(fields[1:], &m.RelinquishCookiesRequestSeen, &m.RelinquishCookiesWithNullParent,
   319  				&m.RelinquishRequestsWaitingCompleteCreation, &m.RelinquishRetries)
   320  			if err != nil {
   321  				return &m, err
   322  			}
   323  		case "AttrChg:":
   324  			err := setFSCacheFields(fields[1:], &m.AttributeChangedRequestsSeen, &m.AttributeChangedRequestsQueued,
   325  				&m.AttributeChangedRejectDueToEnobufs, &m.AttributeChangedFailedDueToEnomem, &m.AttributeChangedOps)
   326  			if err != nil {
   327  				return &m, err
   328  			}
   329  		case "Allocs":
   330  			if strings.Split(fields[2], "=")[0] == "n" {
   331  				err := setFSCacheFields(fields[2:], &m.AllocationRequestsSeen, &m.AllocationOkRequests,
   332  					&m.AllocationWaitingOnLookup, &m.AllocationsRejectedDueToEnobufs, &m.AllocationsAbortedDueToErestartsys)
   333  				if err != nil {
   334  					return &m, err
   335  				}
   336  			} else {
   337  				err := setFSCacheFields(fields[2:], &m.AllocationOperationsSubmitted, &m.AllocationsWaitedForCPU,
   338  					&m.AllocationsAbortedDueToObjectDeath)
   339  				if err != nil {
   340  					return &m, err
   341  				}
   342  			}
   343  		case "Retrvls:":
   344  			if strings.Split(fields[1], "=")[0] == "n" {
   345  				err := setFSCacheFields(fields[1:], &m.RetrievalsReadRequests, &m.RetrievalsOk, &m.RetrievalsWaitingLookupCompletion,
   346  					&m.RetrievalsReturnedEnodata, &m.RetrievalsRejectedDueToEnobufs, &m.RetrievalsAbortedDueToErestartsys,
   347  					&m.RetrievalsFailedDueToEnomem)
   348  				if err != nil {
   349  					return &m, err
   350  				}
   351  			} else {
   352  				err := setFSCacheFields(fields[1:], &m.RetrievalsRequests, &m.RetrievalsWaitingCPU, &m.RetrievalsAbortedDueToObjectDeath)
   353  				if err != nil {
   354  					return &m, err
   355  				}
   356  			}
   357  		case "Stores":
   358  			if strings.Split(fields[2], "=")[0] == "n" {
   359  				err := setFSCacheFields(fields[2:], &m.StoreWriteRequests, &m.StoreSuccessfulRequests,
   360  					&m.StoreRequestsOnPendingStorage, &m.StoreRequestsRejectedDueToEnobufs, &m.StoreRequestsFailedDueToEnomem)
   361  				if err != nil {
   362  					return &m, err
   363  				}
   364  			} else {
   365  				err := setFSCacheFields(fields[2:], &m.StoreRequestsSubmitted, &m.StoreRequestsRunning,
   366  					&m.StorePagesWithRequestsProcessing, &m.StoreRequestsDeleted, &m.StoreRequestsOverStoreLimit)
   367  				if err != nil {
   368  					return &m, err
   369  				}
   370  			}
   371  		case "VmScan":
   372  			err := setFSCacheFields(fields[2:], &m.ReleaseRequestsAgainstPagesWithNoPendingStorage,
   373  				&m.ReleaseRequestsAgainstPagesStoredByTimeLockGranted, &m.ReleaseRequestsIgnoredDueToInProgressStore,
   374  				&m.PageStoresCancelledByReleaseRequests, &m.VmscanWaiting)
   375  			if err != nil {
   376  				return &m, err
   377  			}
   378  		case "Ops":
   379  			if strings.Split(fields[2], "=")[0] == "pend" {
   380  				err := setFSCacheFields(fields[2:], &m.OpsPending, &m.OpsRunning, &m.OpsEnqueued, &m.OpsCancelled, &m.OpsRejected)
   381  				if err != nil {
   382  					return &m, err
   383  				}
   384  			} else {
   385  				err := setFSCacheFields(fields[2:], &m.OpsInitialised, &m.OpsDeferred, &m.OpsReleased, &m.OpsGarbageCollected)
   386  				if err != nil {
   387  					return &m, err
   388  				}
   389  			}
   390  		case "CacheOp:":
   391  			if strings.Split(fields[1], "=")[0] == "alo" {
   392  				err := setFSCacheFields(fields[1:], &m.CacheopAllocationsinProgress, &m.CacheopLookupObjectInProgress,
   393  					&m.CacheopLookupCompleteInPorgress, &m.CacheopGrabObjectInProgress)
   394  				if err != nil {
   395  					return &m, err
   396  				}
   397  			} else if strings.Split(fields[1], "=")[0] == "inv" {
   398  				err := setFSCacheFields(fields[1:], &m.CacheopInvalidations, &m.CacheopUpdateObjectInProgress,
   399  					&m.CacheopDropObjectInProgress, &m.CacheopPutObjectInProgress, &m.CacheopAttributeChangeInProgress,
   400  					&m.CacheopSyncCacheInProgress)
   401  				if err != nil {
   402  					return &m, err
   403  				}
   404  			} else {
   405  				err := setFSCacheFields(fields[1:], &m.CacheopReadOrAllocPageInProgress, &m.CacheopReadOrAllocPagesInProgress,
   406  					&m.CacheopAllocatePageInProgress, &m.CacheopAllocatePagesInProgress, &m.CacheopWritePagesInProgress,
   407  					&m.CacheopUncachePagesInProgress, &m.CacheopDissociatePagesInProgress)
   408  				if err != nil {
   409  					return &m, err
   410  				}
   411  			}
   412  		case "CacheEv:":
   413  			err := setFSCacheFields(fields[1:], &m.CacheevLookupsAndCreationsRejectedLackSpace, &m.CacheevStaleObjectsDeleted,
   414  				&m.CacheevRetiredWhenReliquished, &m.CacheevObjectsCulled)
   415  			if err != nil {
   416  				return &m, err
   417  			}
   418  		}
   419  	}
   420  
   421  	return &m, nil
   422  }
   423
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