Hi,
With the input of Martin, and following my own suggestions:
On Sat, Oct 28, 2006, Loïc Minier wrote:
> On the topic of mounts, I'd like to add:
> * a sanity check to popup a shell if a mount point isn't an empty
> directory after umount
> * reverse order of umounts so that /proc is umounted last
> * perhaps a sanity check to grep /proc/mounts for the base path to the
> chroot and see if anything mounted remains
I completely reworked the patch. A newer version is attached, which I
tested in some scenarios already:
----- Unmounting /proc twice:
-> unmounting proc filesystem
W: Could not unmount proc: umount:
/home/lool/.pbuilder/build/sid/cow.2610/proc: not mounted
W: Ignored error in unmount
----- Unmounting /etc:
-> unmounting etc filesystem
W: Could not unmount etc: umount: /home/lool/.pbuilder/build/sid/cow.4574/etc:
not mounted
W: etc not empty
W: Tried ignoring error in unmount, but sanity check failed: etc might still be
mounted
W: Retrying to unmount etc in 5s
----- Unmounting /etc/passwd:
-> unmounting etc/passwd filesystem
W: Could not unmount etc/passwd: umount:
/home/lool/.pbuilder/build/sid/cow.6381/etc/passwd: not mounted
W: etc/passwd isn't a directory
W: Tried ignoring error in unmount, but sanity check failed: etc/passwd might
still be mounted
W: Retrying to unmount etc/passwd in 5s
----- Launching a process with CWD in the filesystem being unmounted:
-> unmounting dev/pts filesystem
W: Could not unmount dev/pts: umount:
/home/lool/.pbuilder/build/sid/cow.8223/dev/pts: device is busy
umount: /home/lool/.pbuilder/build/sid/cow.8223/dev/pts: device is busy
W: Retrying to unmount dev/pts in 5s
umount: /home/lool/.pbuilder/build/sid/cow.8223/dev/pts: device is busy
It adds a sanity checking function, seems_truly_unmounted, which goes
through great length to fail if there's a slight change that a
mountpoint is still mounted.
I will commit this patch and change the order of umounts so that bind
mounts are unmounted first, and /proc last.
Bye,
--
Loïc Minier <[EMAIL PROTECTED]>
Index: ChangeLog
===================================================================
RCS file: /cvsroot/pbuilder/pbuilder/ChangeLog,v
retrieving revision 1.412
diff -u -r1.412 ChangeLog
--- ChangeLog 29 Oct 2006 02:16:49 -0000 1.412
+++ ChangeLog 29 Oct 2006 23:44:28 -0000
@@ -1,3 +1,10 @@
+2006-10-29 Loic Minier <[EMAIL PROTECTED]>
+
+ * pbuilder-modules: add sanity checks during umount_one(); ignore
+ umount errors of the type "umount: /foobar: not mounted" and "umount:
+ /foobar: not found" as retries will be useless anyway, and these
+ errors shouldn't cause data loss; fixes #391390.
+
2006-10-29 Junichi Uekawa <[EMAIL PROTECTED]>
* Documentation/pbuilder-doc.xml: developer info is updated.
Index: pbuilder-modules
===================================================================
RCS file: /cvsroot/pbuilder/pbuilder/pbuilder-modules,v
retrieving revision 1.99
diff -u -r1.99 pbuilder-modules
--- pbuilder-modules 24 Aug 2006 22:58:57 -0000 1.99
+++ pbuilder-modules 29 Oct 2006 23:44:28 -0000
@@ -86,6 +86,41 @@
exit 1
}
+# test whether a directory is empty
+# fails if "$*" exists but isn't a directory
+# fails and outputs garbage if "$*" doesn't actually exist
+is_empty_dir() {
+ return "$(find "$*" -maxdepth 0 -type d -empty -printf 0 -o -printf 1)"
+}
+
+# sanity checks to ensure mountpoint $1 is truly unmounted in $BUILDPLACE
+# (fails relatively often to ensure we don't "rm -rf" a bind mount)
+function seems_truly_unmounted() {
+ local mountpoint
+ mountpoint="$1"
+ if ! [ -e "$BUILDPLACE/$mountpoint" ]; then
+ echo "W: $mountpoint doesn't exist"
+ return 1
+ fi
+ if ! [ -d "$BUILDPLACE/$mountpoint" ]; then
+ echo "W: $mountpoint isn't a directory"
+ return 1
+ fi
+ if [ -r "$BUILDPLACE/proc/mounts" ] && grep -q "^[^ ]* $mountpoint "
"$BUILDPLACE/proc/mounts"; then
+ echo "W: $mountpoint is mounted according to build place's
/proc/mounts"
+ return 1
+ fi
+ if [ -r "/proc/mounts" ] && grep -q "^[^ ]* $BUILDPLACE/$mountpoint "
"/proc/mounts"; then
+ echo "W: $mountpoint is mounted according to system's /proc/mounts"
+ return 1
+ fi
+ if ! is_empty_dir "$BUILDPLACE/$mountpoint"; then
+ echo "W: $mountpoint not empty"
+ return 1
+ fi
+ return 0
+}
+
function umount_one () {
if [ "${IGNORE_UMOUNT}" = "yes" ]; then
# support ignore umount option.
@@ -93,24 +128,45 @@
return
fi
echo " -> unmounting $1 filesystem"
- if ! umount "$BUILDPLACE/$1"; then
- echo "W: Retrying to unmount $1"
+ local UMOUNT_OUTPUT
+ if ! UMOUNT_OUTPUT="$(LC_ALL=C umount "$BUILDPLACE/$1" 2>&1)"; then
+ echo "W: Could not unmount $1: $UMOUNT_OUTPUT"
+ local ignore_umount_error="no"
+ case $UMOUNT_OUTPUT in
+ "umount: "*": not found"|"umount:"*": not mounted")
+ # run an additional set of sanity checks
+ if seems_truly_unmounted "$1"; then
+ ignore_umount_error="yes"
+ else
+ echo "W: Tried ignoring error in unmount, but sanity check
failed: $1 might still be mounted"
+ fi
+ ;;
+ *)
+ ;;
+ esac
+ if [ "$ignore_umount_error" != "yes" ]; then
+ echo "W: Retrying to unmount $1 in 5s"
sleep 5s
while ! umount "$BUILDPLACE/$1"; do
sleep 5s
cat <<EOF
- Could not unmount $1, there might be some program
- still using files in /proc (klogd?).
- Please check and kill the process manually so that I can unmount $1
+ Could not unmount $1, some programs might
+ still be using files in /proc (klogd?).
+ Please check and kill these processes manually
+ so that I can unmount $1. Last umount error was:
+$UMOUNT_OUTPUT
- This error is only happens with chroot; try using user-mode-linux to
- avoid this message.
+ This error only affects chroots; you may want to use
+ user-mode-linux to avoid this message.
EOF
chroot "$BUILDPLACE" bin/sh
done
- fi
+ else
+ echo "W: Ignored error in unmount"
+ fi
+ fi
}
function umountproc () {
