[LU-11166] Remove all references to the /proc/fs/jbd2/*/history file

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.12.0
• Affects Version/s: Lustre 2.11.0, Lustre 2.12.0, Lustre 2.10.4
• Severity: 3
• Assignee: James Nunez (Inactive)
• Reporter: James Nunez (Inactive)

Description

The /proc/fs/jbd2/*/history file was removed several years ago by Theodore Ts’o’s patch

commit bf6993276f74d46776f35c45ddef29b981b1d1c6
Author: Theodore Ts'o [e-mail]
AuthorDate: Wed Sep 30 00:32:06 2009 -0400
Commit: Theodore Ts'o [e-mail]
CommitDate: Wed Sep 30 00:32:06 2009 -0400

jbd2: Use tracepoints for history file
The /proc/fs/jbd2//history was maintained manually; by using tracepoints, we can get all of the existing functionality of the /proc file plus extra capabilities thanks to the ftrace infrastructure. We save memory as a bonus.

obdfilter-survey and iokit-lstat both look for the jbd history file. Since the history file no longer exists, we should stop these tests and utilities from looking for the file.

Is there an alternate way to get the same information that was contained in /proc/fs/jbd2//history of use the information in the /proc/fs/jbd2//info file? Use tracepoints?

From obdfilter-survey.sh, the following functions are used in tests 1b and 2b.

  93 print_jbd () {
  94         local file=$1
  95         local facet=$2
  96         local varsvc=${facet}_svc
  97         local dev=$(ldiskfs_canon "*.${!varsvc}.mntdev" $facet)
  98 
  99         # ext4: /proc/fs/jbd2/sda1:8/history
 100         # ext3: /proc/fs/jbd/sdb1/history
 101 
 102         do_facet $facet cat /proc/fs/jbd*/${dev}*/$file
 103 }
 104 
 105 check_jbd_values () {
 106         local facet=$1
 107         local thrhi=$2
 108         local rtime=$3
 109 
 110         # last two lines from history
 111         # $4: run >= 5000
 112         # $8: hndls >= thrhi * 2
 113         # display history of rtime/4 before, in case obd cleanup consumes time
 114         local tlines=$((rtime / 5 / 4 + 1))
 115         local hist=("$(print_jbd history $facet | tail -$tlines | head -n1)")
 116         echo "$hist"
 117         local run=($(echo "${hist[*]}" | awk '{print $4}'))
 118         local hndls=($(echo "${hist[*]}" | awk '{print $8}'))
 119 
 120         local rc=0
 121         for (( i=0; i<1; i++)); do
 122                 [[ ${run[i]} -lt 5000 ]] && \
 123                         error "$facet: run expected 5000, have ${run[i]}" && rc=1
 124                 [[ ${hndls[i]} -lt $((thrhi * 2)) ]] && \
 125                         error "$facet: hndls expected > $((thrhi * 2)), have ${hndls[i]}" && rc=2
 126         done
 127         return $rc
 128 }
 129 
 130 check_jbd_values_facets () {
 131         local facets=$1
 132         local thrhi=$2
 133         local rtime=$3
 134         local facet
 135         local rc=0
 136         for facet in  ${facets//,/ }; do
 137                 check_jbd_values $facet $thrhi $rtime || rc=$((rc+$?))
 138         done
 139         return $rc
 140 }
 141 

In iokit-lstat, jbd_collector() cats the file

520 function jbd_collector()
 521 {
 522         local obd=$1
 523         local uuid=$(lctl get_param -n obd.uuid 2>&1)
 524         local tmp=$(lctl get_param -n obd.mntdev 2>&1)
 525         local disk=$(basename $tmp)
 526         local file="/proc/fs/jbd/${disk}/history"
 527 
 528         echo "jbd history for ${uuid}/${disk} " $(date)
 529 
 530         if let "JBD_INTERVAL==0"; then
 531                 idle_collector
 532                 cat $file
 533         elif let "JBD_INTERVAL>0"; then
 534                 idle_collector
 535                 cat $file
 536         else
 537                 echo "Invalid JBD_INTERVAL=$JBD_INTERVAL"
 538                 idle_collector
 539         fi
 540 }
 541 
 542 function jbd_start()
 543 {
 544         if [ "$JBD_INTERVAL" == "" ]; then
 545                 return;
 546         fi
 547 
 548         # find all obdfilters and MDSs
 549         for i in $(lctl list_param obdfilter.* mds.*); do
 550                 obd=$(echo "$i" | awk -F"." '{print $2}')
 551                 if [ "$obd" == "num_refs" ]; then
 552                         continue;
 553                 fi
 554                 local tmp=$(lctl get_param -n ${i}.mntdev 2>&1)
 555                 if [ $? != 0 ]; then
 556                         continue;
 557                 fi
 558                 local disk=$(basename $tmp)
 559                 if [ ! -f /proc/fs/jbd/${disk}/history ]; then
 560                         continue;
 561                 fi
 562                 run_collector "jbd" jbd_collector ${i} &
 563         done
 564 }