Mount snapshots in a different location

In preparation for using autofs to mount snapshots.

run/archiveloop

@@ -471,12 +471,13 @@ function mount_all_snapshots {
   do
     log "mounting snapshot $img"
     imgdir=$(dirname "$img")
-    if mount | grep "$imgdir/mnt"
+    mntdir=/tmp/snapshots/$(basename "$imgdir")
+    if mount | grep "$mntdir"
     then
       echo "$img already mounted"
       return
     fi
-    /root/bin/mount_image.sh "$img" "$imgdir/mnt"
+    /root/bin/mount_image.sh "$img" "$mntdir"
   done
   log "mounted all snapshots"
 }

run/make_snapshot.sh

@@ -117,7 +117,7 @@ function snapshot {
     # shellcheck disable=SC2012
     oldest=$(ls -ldC1 /backingfiles/snapshots/snap-* | head -1)
     log "low space, deleting $oldest"
-    /root/bin/release_snapshot.sh "$oldest/mnt"
+    /root/bin/release_snapshot.sh "$oldest"
     rm -rf "$oldest"
   done
 
@@ -133,26 +133,27 @@ function snapshot {
   local newsnapdir
   oldname=/backingfiles/snapshots/snap-$(printf "%06d" "$oldnum")/snap.bin
   newsnapdir=/backingfiles/snapshots/snap-$(printf "%06d" $newnum)
+  newsnapmnt=/tmp/snapshots/snap-$(printf "%06d" $newnum)
 
-  local newname=$newsnapdir/snap.bin
   local tmpsnapdir=/backingfiles/snapshots/newsnap
   local tmpsnapname=$tmpsnapdir/snap.bin
-  local tmpsnapmnt=$tmpsnapdir/mnt
-  log "taking snapshot of cam disk: $newname"
+  log "taking snapshot of cam disk in $newsnapdir"
   rm -rf "$tmpsnapdir"
-  /root/bin/mount_snapshot.sh /backingfiles/cam_disk.bin "$tmpsnapname" "$tmpsnapmnt"
+  /root/bin/mount_snapshot.sh /backingfiles/cam_disk.bin "$tmpsnapname" "$newsnapmnt"
   log "took snapshot"
 
   # check whether this snapshot is actually different from the previous one
-  find "$tmpsnapmnt/TeslaCam" -type f -printf '%s %P\n' > "$tmpsnapname.toc"
-  log "comparing $oldname.toc and $tmpsnapname.toc"
-  if [[ ! -e "$oldname.toc" ]] || diff "$oldname.toc" "$tmpsnapname.toc" | grep -e '^>'
+  find "$newsnapmnt/TeslaCam" -type f -printf '%s %P\n' > "/tmp/snap.bin.toc"
+  log "comparing new snapshot with $oldname"
+  if [[ ! -e "$oldname.toc" ]] || diff "$oldname.toc" "/tmp/snap.bin.toc" | grep -e '^>'
   then
-    make_links_for_snapshot "$tmpsnapmnt" "$newsnapdir/mnt"
+    ln -s "$newsnapmnt" "$tmpsnapdir/mnt"
+    make_links_for_snapshot "$newsnapmnt" "$newsnapdir/mnt"
     mv "$tmpsnapdir" "$newsnapdir"
+    mv /tmp/snap.bin.toc "$newsnapdir"
   else
     log "new snapshot is identical to previous one, discarding"
-    /root/bin/release_snapshot.sh "$tmpsnapmnt"
+    /root/bin/release_snapshot.sh "$newsnapmnt"
     rm -rf "$tmpsnapdir"
   fi
 }

run/mount_image.sh

@@ -25,3 +25,11 @@ PARTLOOP=$(losetup -j "$SNAP" | awk '{print $1}' | sed 's/:/p1/')
 echo mount "$PARTLOOP" "$MNT"
 mount -o ro "$PARTLOOP" "$MNT"
 
+# if the image was created using the old mounting scheme,
+# switch it over to the new one
+mntlink=$(dirname "$SNAP")/mnt
+if [ ! -L "$mntlink" ] && [ -d "$mntlink" ]
+then
+  rmdir "$mntlink"
+  ln -sf "$MNT" "$mntlink"
+fi

run/release_snapshot.sh

@@ -1,13 +1,18 @@
-#!/bin/sh
+#!/bin/bash -eu
 
 # for some reason "umount -d" doesn't remove the loop device, so we have to remove it ourselves
-MNT=$(echo "$1" | sed 's/\/$//')
-LOOP=$(mount | grep -w "$MNT" | awk '{print $1}' | sed 's/p1$//')
+NAME=$(basename "$1")
+LOOPPART=$(mount | grep -w "$NAME" | awk '{print $1}')
+LOOPROOT=${LOOPPART/p1/}
+MNT=$(findmnt -o target -n $LOOPPART)
 umount "$MNT"
-losetup -d "$LOOP"
+losetup -d "$LOOPROOT"
+
+# delete the snapshot folders
+rm -rf /backingfiles/snapshots/$NAME /tmp/snapshots/$NAME
 
 # delete all dead links
 find /backingfiles/TeslaCam/ -depth -xtype l -delete || true
 
 # delete all Sentry, saved and recent folders that are now empty
-find /backingfiles/TeslaCam/ -mindepth 2 -depth -type d -empty -exec rmdir "{}" \;
+find /backingfiles/TeslaCam/ -mindepth 2 -depth -type d -empty -exec rmdir "{}" \;

tools/checksnapshotlinks.sh

@@ -14,7 +14,7 @@ function recentpathfor {
   echo "RecentClips/$filedate/$filename"
 }
 
-find /backingfiles/snapshots/ -type f -name \*.mp4 | sort -r | {
+find -L /backingfiles/snapshots/ -type f -name \*.mp4 | sort -r | {
   while read -r path
   do
     name=${path##/*TeslaCam/}