From: Masatake YAMATO <yamato@redhat.com>
Date: Sat, 26 Feb 2022 18:42:09 +0000 (+0900)
Subject: tests: (lsfd) don't use findmnt to verify device numbers
X-Git-Tag: v2.38-rc2~12^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0c403cc14378a728501bacacc375c5a591886523;p=thirdparty%2Futil-linux.git

tests: (lsfd) don't use findmnt to verify device numbers

This change tries to fix the failures in testing reported in:

* https://lkml.org/lkml/2022/1/31/1333, and
* https://lkml.org/lkml/2022/2/2/171

The original test cases depended on a wrong assumption; if M and M'
are the same, D and D' are the same, too.  Here, M is a mnt_id in
/proc/$pid/mountinfo. D is the device number for M in
/proc/$pid/mountinfo. M' is the mnt_id value in
/proc/$pid/fdinfo/$fd. D' is the device number reported by stat
syscall for /proc/$pid/fd/$fd.

  # ../../lsfd -oCOMMAND,PID,MNTID,DEV,NAME -p 2972623 -Q '(ASSOC =~ "^[0-9]+$") and (TYPE == "REG")'
  COMMAND     PID MNTID  DEV NAME
  a.out   2972623  1578 0:98 /home/jet/var/util-linux/o/merged/y
  # stat -c %d /home/jet/var/util-linux/o/merged/y
  98
  # grep 1578 /proc/2972623/mountinfo
  1578 91 0:91 / /home/jet/var/util-linux/o/merged rw,relatime shared:724 - overlay overlay rw,seclabel,lowerdir=lower-base/lower,upperdir=upper-base/upper,workdir=upper-base/work

The original test compared the device numbers reported by findmnt and
lsfd. findmnt retrieves a device number from /proc/$pid/mountinfo.
lsfd retrieves a device number from stat syscall.

This assumption is not correct for a file on an overlay file system
whose block devices behind lowerdir and upperdir are different.
Using findmnt is not suitable for comparing device numbers.

This change uses stat command instead of findmnt to retrieve the
device number.

Reported-by: Anatoly Pugachev <matorola@gmail.com>
Reported-by: Chris Hofstaedtler <zeha@debian.org>
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---

diff --git a/tests/expected/lsfd/mkfds-ro-block-device b/tests/expected/lsfd/mkfds-ro-block-device
index 11f0aa01ee..3b2fe07c29 100644
--- a/tests/expected/lsfd/mkfds-ro-block-device
+++ b/tests/expected/lsfd/mkfds-ro-block-device
@@ -8,7 +8,6 @@ MAJ_MIN[RUN]: 0
 MAJ_MIN[STR]: 0
 RDEV[RUN]: 0
 RDEV[STR]: 0
-MNTID[RUN]: 0
 DEV[RUN]: 0
-FINDMNT[RUN]: 0
-DEV[STR]: 0
+STAT[RUN]: 0
+DEVNUM[STR]: 0
diff --git a/tests/expected/lsfd/mkfds-ro-regular-file b/tests/expected/lsfd/mkfds-ro-regular-file
index c8fef02765..092f40b165 100644
--- a/tests/expected/lsfd/mkfds-ro-regular-file
+++ b/tests/expected/lsfd/mkfds-ro-regular-file
@@ -10,7 +10,6 @@ USER[RUN]: 0
 USER[STR]: 0
 SIZE[RUN]: 0
 SIZE[STR]: 0
-MNTID[RUN]: 0
 DEV[RUN]: 0
-FINDMNT[RUN]: 0
-DEV[STR]: 0
+STAT[RUN]: 0
+DEVNUM[STR]: 0
diff --git a/tests/expected/lsfd/mkfds-rw-character-device b/tests/expected/lsfd/mkfds-rw-character-device
index e33dc97d5b..00423f4f02 100644
--- a/tests/expected/lsfd/mkfds-rw-character-device
+++ b/tests/expected/lsfd/mkfds-rw-character-device
@@ -1,6 +1,5 @@
     3  rw-  CHR /dev/zero  mem:5   0     1:5    mem    char  1:5
 ASSOC,MODE,TYPE,NAME,SOURCE,POS,MAJ:MIN,CHRDRV,DEVTYPE,RDEV: 0
-MNTID[RUN]: 0
 DEV[RUN]: 0
-FINDMNT[RUN]: 0
-DEV[STR]: 0
+STAT[RUN]: 0
+DEVNUM[STR]: 0
diff --git a/tests/ts/lsfd/lsfd-functions.bash b/tests/ts/lsfd/lsfd-functions.bash
index c46dc06301..b57ba118f4 100644
--- a/tests/ts/lsfd/lsfd-functions.bash
+++ b/tests/ts/lsfd/lsfd-functions.bash
@@ -26,31 +26,28 @@ function lsfd_wait_for_pausing {
 
 function lsfd_compare_dev {
     local LSFD=$1
-    local FINDMNT=$2
+    local FILE=$2
     local EXPR=$3
 
     ts_check_prog "grep"
+    ts_check_prog "expr"
+    ts_check_prog "stat"
 
-    local MNTID=$("${LSFD}" --raw -n -o MNTID -Q "${EXPR}")
-    echo 'MNTID[RUN]:' $?
     local DEV=$("${LSFD}" --raw -n -o DEV -Q "${EXPR}")
     echo 'DEV[RUN]:' $?
-    # "stat -c" %d or "stat -c %D" can be used here instead of "findmnt".
-    # "stat" just prints a device id.
-    # Unlike "stat", "findmnt" can print the major part and minor part
-    # for a given device separately.
-    # We can save the code for extracting the major part and minor part
-    # if we use findmnt.
-    local FINDMNT_MNTID_DEV=$("${FINDMNT}" --raw -n -o ID,MAJ:MIN | grep "^${MNTID}\b")
-    echo 'FINDMNT[RUN]:' $?
-    if [ "${MNTID} ${DEV}" == "${FINDMNT_MNTID_DEV}" ]; then
-	echo 'DEV[STR]:' 0
+    local MAJ=${DEV%:*}
+    local MIN=${DEV#*:}
+    local DEVNUM=$(( ( MAJ << 8 ) + MIN ))
+    local STAT_DEVNUM=$(stat -c "%d" "$FILE")
+    echo 'STAT[RUN]:' $?
+    if [ "${DEVNUM}" == "${STAT_DEVNUM}" ]; then
+	echo 'DEVNUM[STR]:' 0
     else
-	echo 'DEV[STR]:' 1
+	echo 'DEVNUM[STR]:' 1
 	# Print more information for debugging
-	echo 'MNTID:' "${MNTID}"
 	echo 'DEV:' "${DEV}"
-	echo 'MNTID DEV:' "${MNTID} ${DEV}"
-	echo 'FINDMNT_MNTID_DEV:' "${FINDMNT_MNTID_DEV}"
+	echo 'MAJ:MIN' "${MAJ}:${MIN}"
+	echo 'DEVNUM:' "${DEVNUM}"
+	echo 'STAT_DEVNUM:' "${STAT_DEVNUM}"
     fi
 }
diff --git a/tests/ts/lsfd/mkfds-ro-block-device b/tests/ts/lsfd/mkfds-ro-block-device
index 4cf8011c85..86c1ba874b 100755
--- a/tests/ts/lsfd/mkfds-ro-block-device
+++ b/tests/ts/lsfd/mkfds-ro-block-device
@@ -65,7 +65,7 @@ EXPR=
 	[ "${LSFD_RDEV}" == 7:"${LSFD_LOOP_BDEV_NUM}" ]
 	echo 'RDEV[STR]:' $?
 
-	lsfd_compare_dev "${TS_CMD_LSFD}" "${TS_CMD_FINDMNT}" "${EXPR}"
+	lsfd_compare_dev "${TS_CMD_LSFD}" "${LSFD_LOOP_BDEV}" "${EXPR}"
 
 	kill -CONT ${PID}
 	wait ${MKFDS_PID}
diff --git a/tests/ts/lsfd/mkfds-ro-regular-file b/tests/ts/lsfd/mkfds-ro-regular-file
index 1485d74c7d..9441a4ea03 100755
--- a/tests/ts/lsfd/mkfds-ro-regular-file
+++ b/tests/ts/lsfd/mkfds-ro-regular-file
@@ -23,7 +23,6 @@ ts_init "$*"
 . $TS_SELF/lsfd-functions.bash
 
 ts_check_test_command "$TS_CMD_LSFD"
-ts_check_test_command "$TS_CMD_FINDMNT"
 
 ts_check_test_command "$TS_HELPER_MKFDS"
 
@@ -37,7 +36,8 @@ FD=3
 EXPR=
 
 {
-    coproc MKFDS { "$TS_HELPER_MKFDS" --comm ABC ro-regular-file $FD offset=1; }
+    target=/etc/passwd
+    coproc MKFDS { "$TS_HELPER_MKFDS" --comm ABC ro-regular-file $FD offset=1 file=$target; }
     if read -u ${MKFDS[0]} PID; then
 	EXPR='(PID == '"${PID}"') and (FD == '"$FD"')'
 	${TS_CMD_LSFD} -n -o COMMAND,ASSOC,MODE,TYPE,NAME,POS -Q "${EXPR}"
@@ -50,7 +50,7 @@ EXPR=
 
 	LSFD_INODE=$(${TS_CMD_LSFD} --raw -n -o INODE -Q "${EXPR}")
 	echo 'INODE[RUN]:' $?
-	[ "${LSFD_INODE}"  == "$(stat -c %i /etc/passwd)" ]
+	[ "${LSFD_INODE}"  == "$(stat -c %i $target)" ]
 	echo 'INODE[STR]:' $?
 
 	LSFD_UID=$(${TS_CMD_LSFD} --raw -n -o UID -Q "${EXPR}")
@@ -65,10 +65,10 @@ EXPR=
 
 	LSFD_SIZE=$(${TS_CMD_LSFD} --raw -n -o SIZE -Q "${EXPR}")
 	echo 'SIZE[RUN]:' $?
-	[ "${LSFD_SIZE}" == $(stat -c %s /etc/passwd) ]
+	[ "${LSFD_SIZE}" == $(stat -c %s $target) ]
 	echo 'SIZE[STR]:' $?
 
-	lsfd_compare_dev "${TS_CMD_LSFD}" "${TS_CMD_FINDMNT}" "${EXPR}"
+	lsfd_compare_dev "${TS_CMD_LSFD}" $target "${EXPR}"
 
 	kill -CONT ${PID}
 	wait ${MKFDS_PID}
diff --git a/tests/ts/lsfd/mkfds-rw-character-device b/tests/ts/lsfd/mkfds-rw-character-device
index ea10e7d81d..aeee7a556c 100755
--- a/tests/ts/lsfd/mkfds-rw-character-device
+++ b/tests/ts/lsfd/mkfds-rw-character-device
@@ -23,7 +23,6 @@ ts_init "$*"
 . $TS_SELF/lsfd-functions.bash
 
 ts_check_test_command "$TS_CMD_LSFD"
-ts_check_test_command "$TS_CMD_FINDMNT"
 
 ts_check_test_command "$TS_HELPER_MKFDS"
 
@@ -36,13 +35,14 @@ FD=3
 EXPR=
 
 {
-    coproc MKFDS { "$TS_HELPER_MKFDS" rw-character-device $FD chrdev=/dev/zero; }
+    target=/dev/zero
+    coproc MKFDS { "$TS_HELPER_MKFDS" rw-character-device $FD chrdev=$target; }
     if read -u ${MKFDS[0]} PID; then
 	EXPR='(PID == '"${PID}"') and (FD == '"$FD"')'
 	${TS_CMD_LSFD} -n -o ASSOC,MODE,TYPE,NAME,SOURCE,POS,MAJ:MIN,CHRDRV,DEVTYPE,RDEV -Q "${EXPR}"
 	echo 'ASSOC,MODE,TYPE,NAME,SOURCE,POS,MAJ:MIN,CHRDRV,DEVTYPE,RDEV': $?
 
-	lsfd_compare_dev "${TS_CMD_LSFD}" "${TS_CMD_FINDMNT}" "${EXPR}"
+	lsfd_compare_dev "${TS_CMD_LSFD}" $target "${EXPR}"
 
 	kill -CONT ${PID}
 	wait ${MKFDS_PID}