ovlsnapshot: use path <mnt>@ instead of <mnt>/@ as snapshots dir

Avoid "overlapping upper dir" mount error. Create all snapshot dirs not under lower dir (<mnt>). Signed-off-by: Amir Goldstein <[email protected]>
amir73il · Jan 20, 2020 · 9b94278 · 9b94278
1 parent 73ed9ce
commit 9b94278
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Showing 3 changed files with 31 additions and 31 deletions.
diff --git a/scripts/mount.snapshot b/scripts/mount.snapshot
@@ -1,13 +1,13 @@
 #!/bin/sh
 # mount.snapshot <dev> <mnt> [-o <opt>]
-# mount.snapshot <dev> <mnt>/@/_
-# mount.snapshot <dev> <mnt>/@/_ -o remount
+# mount.snapshot <dev> <mnt>@/_
+# mount.snapshot <dev> <mnt>@/_ -o remount
 #
 # Overlayfs snapshot mount helper
 #
-# - Check if snapshots stack exists at <mnt>/@/.snapshots
-# - Mount (or remount) snapshot mount at <mnt>/@/_
-# - Mount snapshot overlays at <mnt>/@/<id>/_
+# - Check if snapshots stack exists at <mnt>@/.snapshots
+# - Mount (or remount) snapshot mount at <mnt>@/_
+# - Mount snapshot overlays at <mnt>@/<id>/_
 #
 # * If any mount flags other than -o rw[,remount] are passed to helper,
 #   it passes the command as is without doing the above
@@ -77,9 +77,9 @@ if ( echo "$mntopts" | grep -q remount ) ; then
 	REMOUNT=true
 fi
 
-# Try to parse <mnt> from <mnt>/@/_
+# Try to parse <mnt> from <mnt>@/_
 mntdir="$mnt"
-mnt="${mntdir%/@/_}"
+mnt="${mntdir%@/_}"
 [ "$mnt" != "$mntdir" ] || mount_internal
 
 if $REMOUNT; then
@@ -88,9 +88,9 @@ if $REMOUNT; then
 	mntopts="rw,remount"
 	# snapshot overlays do not support remount -
 	# they have to be umounted/mounted
-	umount -i "$mnt"/@/*/_ 2>/dev/null
+	umount -i "$mnt"@/*/_ 2>/dev/null
 else
-	# Verify snapshot is not already mounted on <mnt>/@/_
+	# Verify snapshot is not already mounted on <mnt>@/_
 	mount -t snapshot | while read d on m opt; do
 		[ "$m" != "$mntdir" -a "$m" != "$mnt" ] || \
 			error "overlayfs snapshot already mounted at '$m'."
@@ -106,7 +106,7 @@ snapmntopts="noatime,index=on,nfs_export=on,redirect_dir=origin"
 oldsnapmntopts="noatime"
 
 lower="$mnt"
-snapdir="$mnt/@"
+snapdir="$mnt@"
 snapshots="$snapdir/.snapshots"
 [ ! -s "$snapshots" ] || id=$(tail -n 1 "$snapshots")
 
@@ -119,10 +119,10 @@ if [ -z "$id" ]; then
 	exit 0
 fi
 
-cd "$lower" || exit 1
+cd "$snapdir" || exit 1
 
 # Relative to $lower to keep overlay mount options shorter
-current="@/$id"
+current="$id"
 upper="$current/u"
 work="$current/w"
 snapmnt="$current/_"
@@ -144,7 +144,7 @@ mount_old_snapshots()
 	# mount snapshots from newest to oldest
 	tac "$snapshots" | while read old; do
 		[ "$old" != "$id" ] || continue
-		oldsnap="@/$old"
+		oldsnap="$old"
 		oldmnt="$oldsnap/_"
 		[ -d "$oldsnap" ] || continue
 		[ -d "$oldmnt" ] || continue

diff --git a/scripts/ovlsnapshot b/scripts/ovlsnapshot
@@ -85,17 +85,17 @@ usage()
 	echo "$FSTYPE snapshot commands:"
 	echo "usage: $SCRIPT_NAME {status|list}  [<path>|-a]"
 	echo "usage: $SCRIPT_NAME {umount|mount} [<path>|-a]"
-	echo "usage: $SCRIPT_NAME {create|take}  <path>[[/]@[/]<snapshot-name>] (default-name=<date.time>)"
-	echo "usage: $SCRIPT_NAME {delete|remove} <path>[/]@[/]<snapshot-name>"
+	echo "usage: $SCRIPT_NAME {create|take}  <path>[@[/]<snapshot-name>] (default-name=<date.time>)"
+	echo "usage: $SCRIPT_NAME {delete|remove} <path>@[/]<snapshot-name>"
 	echo "usage: $SCRIPT_NAME {clean}         <path>"
 	echo
 	echo "snapshot command parameter may be given in ZFS style <path>@<snapshot-name>"
-        echo "and it may be given as the snapshot directory path <path>/@/<snapshot-name>."
+        echo "and it may be given as the snapshot directory path <path>@/<snapshot-name>."
 	echo "If <snapshot-name> part is omitted, command may apply to all snapshots (e.g. umount)."
 	echo
 	echo "$FSTYPE snapshot test commands:"
 	echo "usage: $SCRIPT_NAME {test|tests} <path> [test-number] [file-size-mb]"
-	echo "usage: $SCRIPT_NAME {check}      <path>[[/]@[/]<snapshot-name>]"
+	echo "usage: $SCRIPT_NAME {check}      <path>[@[/]<snapshot-name>]"
 	echo
 	exit $1
 }
@@ -117,10 +117,10 @@ parse_path_snapshot_arg()
 	MNT=${1%/}
 	snap=${2#/}
 	# directory inside <path> to store snapshot related files
-	SNAPDIR=$MNT/@
+	SNAPDIR=$MNT@
 	# directory prefix for snapshot mount points
 	# snaphot mount points will be created as $SNAPROOT/<snapshot-name>/_
-	SNAPROOT=$MNT/@
+	SNAPROOT=$MNT@
 	SNAPMNT=$SNAPROOT/_
 	# file to store snapshots stack
 	SNAPSHOTS="$SNAPDIR/.snapshots"
@@ -484,7 +484,7 @@ case "$CMD" in
   create|take)
 	if [ "$2" = help ]; then
 		echo "$CMD: create a new snapshot."
-		echo "usage: $SCRIPT_NAME {create|take} <path>[[/]@[/]<snapshot-name>] (default-name=<date.time>)"
+		echo "usage: $SCRIPT_NAME {create|take} <path>[@[/]<snapshot-name>] (default-name=<date.time>)"
 		exit 0
 	fi
 	if [ -z "$snap" ] ; then
@@ -507,7 +507,7 @@ case "$CMD" in
 		echo "delete: umount a snapshot and mark it for deletion."
 		echo "any non-mounted snapshot can be marked for deletion"
 		echo "but some snapshot deletion is deferred to later time."
-		echo "usage: $SCRIPT_NAME delete <path>[/]@[/]<snapshot-name>"
+		echo "usage: $SCRIPT_NAME delete <path>@[/]<snapshot-name>"
 		exit 0
 	fi
 	[ -n "$snap" ] || usage 1
@@ -530,7 +530,7 @@ case "$CMD" in
 		echo "remove: delete a snapshot permanently."
 		echo "this command will fail for active snapshot and snapshots"
 		echo "in use by older snapshots. try using the delete command."
-		echo "usage: $SCRIPT_NAME remove <path>[/]@[/]<snapshot-name>"
+		echo "usage: $SCRIPT_NAME remove <path>@[/]<snapshot-name>"
 		exit 0
 	fi
 	[ -n "$snap" ] || usage 1
@@ -727,7 +727,7 @@ case "$CMD" in
   check)
 	if [ "$2" = help ]; then
 		echo "check: verify content of test snapshot."
-		echo "usage: $SCRIPT_NAME check <path>[[/]@[/]<snapshot-name>]"
+		echo "usage: $SCRIPT_NAME check <path>[@[/]<snapshot-name>]"
 		exit 0
 	fi
 	lstest $snap

diff --git a/scripts/umount.snapshot b/scripts/umount.snapshot
@@ -1,13 +1,13 @@
 #!/bin/sh
 # umount.snapshot <mnt>
-# umount.snapshot <mnt>/@/_
+# umount.snapshot <mnt>@/_
 #
 # Overlayfs snapshot umount helper
 #
-# - Unmount snapshot overlays <mnt>/@/*/_
-# - Unmount snapshot mount at <mnt>/@/_
+# - Unmount snapshot overlays <mnt>@/*/_
+# - Unmount snapshot mount at <mnt>@/_
 #
-# * If mount point does not end with /@/_, pass the command as is
+# * If mount point does not end with @/_, pass the command as is
 #   without doing the above
 #
 #-----------------------------------------------------------------------
@@ -34,17 +34,17 @@ mnt="${1%/}"
 
 [ -d "$mnt" ] || exit 1
 
-# Try to parse <mnt> from <mnt>/@/_
+# Try to parse <mnt> from <mnt>@/_
 mntdir="$mnt"
-mnt="${mntdir%/@/_}"
+mnt="${mntdir%@/_}"
 
-# If mount point doesn't end with /@/_ bypass helper.
+# If mount point doesn't end with @/_ bypass helper.
 if [ "$mnt" = "$mntdir" ]; then
 	echo "$*" > /tmp/umount.snapshot.in
 	exec umount -i $*
 fi
 
-snapdir="$mnt/@"
+snapdir="$mnt@"
 snapshots="$snapdir/.snapshots"
 
 umount_snapshots()