From 916d8338b56b514b8f0ef72530a627fa28463140 Mon Sep 17 00:00:00 2001

From: Gene Czarcinski <gczarcinski@gmail.com>

Date: Thu, 31 Jan 2013 23:58:53 +0330

Subject: [PATCH 08/18] Improve btrfs detection support (#888341)

Enables os-prober to detect multiple installations that live in separate

btrfs storage pools.

Resolves: rhbz#888341

---

 README.btrfs                             |  15 ++++

 common.sh                                |  13 ++-

 linux-boot-prober                        | 133 ++++++++++++++++++++++++++++++-

 linux-boot-probes/mounted/common/40grub2 |  12 ++-

 os-prober                                |  28 ++++++-

 os-probes/common/50mounted-tests         |  98 +++++++++++++++++++++--

 os-probes/mounted/common/90linux-distro  |   8 +-

 7 files changed, 293 insertions(+), 14 deletions(-)

 create mode 100644 README.btrfs

diff --git a/README.btrfs b/README.btrfs

new file mode 100644

index 0000000..f9b4d45

--- /dev/null

+++ b/README.btrfs

@@ -0,0 +1,15 @@

+BTRFS is a new filesystem which combines the filesystem with logical volume

+management (subvolumes).  For further information, see:

+      https://btrfs.wiki.kernel.org/index.php/Main_Page

+      https://btrfs.wiki.kernel.org/index.php/FAQ

+

+In order to support BTRFS, a number of changes were necessary to os-prober,

+os-probes/common/50mounted-tests, os-probes/mounted/common/90linux-distro,

+linux-boot-prober, and linux-boot-probes/common/50mounted-tests.

+

+The biggest impact will be to grub2 where there is additional information

+output by os-prober and where, if a BTRFS subvolume is being used for root,

+the parameters for linux-boot-prober have changed.

+

+Sun 30 Dec 2012 11:49:52 AM EST Gene Czarcinski <gene@czarc.net>

+

diff --git a/common.sh b/common.sh

index 19ef90a..85d13f0 100644

--- a/common.sh

+++ b/common.sh

@@ -127,6 +127,7 @@ parse_proc_mounts () {

 	done

 }

+# add forth parameter to pickup btrfs subvol info

 parsefstab () {

 	while read -r line; do

 		case "$line" in

@@ -137,12 +138,22 @@ parsefstab () {

 				set -f

 				set -- $line

 				set +f

-				printf '%s %s %s\n' "$1" "$2" "$3"

+				printf '%s %s %s %s\n' "$1" "$2" "$3" "$4"

 			;;

 		esac

 	done

 }

+#check_btrfs_mounted $bootsv $bootuuid)

+check_btrfs_mounted () {

+	bootsv="$1"

+	bootuuid="$2"

+	bootdev=$(blkid | grep "$bootuuid" | cut -d ':' -f  1)

+	bindfrom=$(grep " btrfs " /proc/self/mountinfo | 

+		   grep " $bootdev " | grep " /$bootsv " | cut -d ' ' -f 5)

+	printf "%s" "$bindfrom"

+}

+

 unescape_mount () {

 	printf %s "$1" | \

 		sed 's/\\011/	/g; s/\\012/\n/g; s/\\040/ /g; s/\\134/\\/g'

diff --git a/linux-boot-prober b/linux-boot-prober

index e32dc84..505c2fd 100755

--- a/linux-boot-prober

+++ b/linux-boot-prober

@@ -5,16 +5,143 @@ set -e

 newns "$@"

 require_tmpdir

+ERR="n"

+

+tmpmnt=/var/lib/os-prober/mount

+if [ ! -d "$tmpmnt" ]; then

+	mkdir "$tmpmnt"

+fi

+

+mounted=

+bootmnt=

+bootsv=

+bootuuid=

 grep "^/dev/" /proc/mounts | parse_proc_mounts >"$OS_PROBER_TMP/mounted-map" || true

-partition="$1"

+if [ -z "$1" ]; then

+	ERR=y

+elif [ "$1" = btrfs -a -z "$2" ]; then

+	ERR=y

+elif [ "$1" = btrfs -a -z "$3" ]; then

+	ERR=y

+elif [ "$1" = btrfs ]; then

+	type=btrfs

+	echo "$2" | grep -q "^UUID=" || ERR=y

+	echo "$3" | grep -q "^subvol=" || ERR=y	

+	export "$2"

+	export "$3"

+	partition=$(blkid | grep "$UUID" | cut -d ':' -f 1 | tr '\n' ' ' | cut -d ' ' -f 1)

+	debug "btrfs: partition=$partition, UUID=$UUID, subvol=$subvol"

+else

+	partition="$1"

+	type=other

+fi

-if [ -z "$partition" ]; then

+if [ "x$ERR" != xn ]; then

 	echo "usage: linux-boot-prober partition" >&2

+	echo "       linux-boot-prober btrfs UUID=<> subvol=<>" >&2

 	exit 1

 fi

+if [ "$type" = btrfs ]; then

+	# handle all of the btrfs stuff here

+	if [ ! -e "/proc/self/mountinfo" ]; then

+		warn "/proc/self/mountinfo does not exist, exiting"

+		umount "$tmpmnt" 2>/dev/null

+		rmdir "$tmpmnt" 2>/dev/null

+		exit 1

+	fi

+	mpoint=$(grep "btrfs" /proc/self/mountinfo | grep " /$subvol " | grep " $partition " | cut -d ' ' -f 5)

+	if [ "$mpoint" = "/" ]; then

+		warn "specifying active root not valid, exiting"

+		umount "$tmpmnt" 2>/dev/null

+		rmdir "$tmpmnt" 2>/dev/null

+		exit 1

+	fi

+	if [ "$mpoint" = "$tmpmnt" ]; then

+		warn "btrfs subvol=$subvool, UUID=$UUID, already mounted on $tmpmnt **ERROR**"

+		umount "$tmpmnt" 2>/dev/null

+		rmdir "$tmpmnt" 2>/dev/null

+		exit 1

+	fi

+	if [ -z "$mpoint" ]; then

+		# mount the btrfs root

+		if ! mount -o subvol=$subvol -t btrfs -U $UUID "$tmpmnt" 2>/dev/null; then

+			warn "error mounting btrfs subvol=$subvol UUID=$UUID"

+			umount "$tmpmnt/boot" 2>/dev/null

+			umount "$tmpmnt" 2>/dev/null

+			rmdir "$tmpmnt" 2>/dev/null

+			exit 1

+		fi

+	else

+		# bind-mount

+		if ! mount -o bind "$mpoint" "$tmpmnt" 2>/dev/null; then

+			warn "error mounting btrfs bindfrom=$mpoint subvol=$subvol UUID=$UUID"

+			umount "$tmpmnt/boot" 2>/dev/null

+			umount "$tmpmnt" 2>/dev/null

+			rmdir "$tmpmnt" 2>/dev/null

+			exit 1

+		fi

+	fi

+	debug "mounted btrfs $partition, subvol=$subvol on $tmpmnt"

+	if [ ! -e "$tmpmnt/etc/fstab" ]; then

+		warn "btrfs subvol=$subvol not root"

+		umount "$tmpmnt" 2>/dev/null

+		rmdir "$tmpmnt" 2>/dev/null

+		exit 1

+	fi

+	bootmnt=$(parsefstab < "$tmpmnt/etc/fstab" | grep " /boot ") || true

+	if [ -z "$bootmnt" ]; then

+		# /boot is part of the root

+		bootpart="$partition"

+		bootsv="$subvol"

+	elif echo "$bootmnt" | cut -d ' ' -f 3 | grep -q "btrfs"; then

+		# separate btrfs /boot subvolume

+		bootsv=$(echo "$bootmnt" | cut -d ' ' -f 4 | grep "^subvol=" | sed "s/subvol=//" )

+		bootuuid=$(echo "$bootmnt" | cut -d ' ' -f 1 | grep "^UUID=" | sed "s/UUID=//" )

+		debug "mounting btrfs $tmpmnt/boot UUID=$bootuuid subvol=$bootsv"

+		bindfrom=$(check_btrfs_mounted $bootsv $bootuuid)

+		if [ -n "$bindfrom" ]; then

+			# already mounted some place

+			if ! mount -o bind $bindfrom "$tmpmnt/boot" 2>/dev/null; then

+				warn "error bind mounting btrfs boot subvol=$bootsv, from=$bindfrom"

+				umount "$tmpmnt/boot" 2>/dev/null

+				umount "$tmpmnt" 2>/dev/null

+				rmdir "$tmpmnt" 2>/dev/null

+				exit 1

+			fi

+		elif ! mount -o subvol=$bootsv -t btrfs -U $bootuuid "$tmpmnt/boot" 2>/dev/null; then

+			warn "error mounting btrfs boot partition subvol=$bootsv, UUID=$bootuuid"

+			umount "$tmpmnt/boot" 2>/dev/null

+			umount "$tmpmnt" 2>/dev/null

+			rmdir "$tmpmnt" 2>/dev/null

+			exit 1

+		fi

+		bootpart=$(grep " btrfs " /proc/self/mountinfo | grep " /$bootsv " | cut -d ' ' -f 10)

+	else

+		# non-btrfs partition or logical volume

+		linux_mount_boot $partition $tmpmnt

+		bootpart="${mountboot%% *}"

+		bootsv=

+	fi

+	

+	test="/usr/lib/linux-boot-probes/mounted/40grub2"

+	if [ -f $test ] && [ -x $test ]; then

+		debug "running $test $partition $bootpart $tmpmnt $type $subvol $bootsv"

+		if $test "$partition" "$bootpart" "$tmpmnt" "$type" "$subvol" "$bootsv"; then

+			debug "$test succeeded"

+		fi

+	fi

+	umount "$tmpmnt/boot" 2>/dev/null || true

+	if ! umount "$tmpmnt" 2>/dev/null; then

+		warn "problem umount $tmpmnt"

+	fi

+	rmdir "$tmpmnt" 2>/dev/null || true

+

+	exit 0

+fi

+

 if ! mapped="$(mapdevfs "$partition")"; then

 	log "Device '$partition' does not exist; skipping"

 	continue

@@ -22,8 +149,8 @@ fi

 if ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map"; then

 	for test in /usr/lib/linux-boot-probes/*; do

-		debug "running $test"

 		if [ -x $test ] && [ -f $test ]; then

+			debug "running $test"

 			if $test "$partition"; then

 				debug "linux detected by $test"

 				break

diff --git a/linux-boot-probes/mounted/common/40grub2 b/linux-boot-probes/mounted/common/40grub2

index 885614e..11ffa1b 100755

--- a/linux-boot-probes/mounted/common/40grub2

+++ b/linux-boot-probes/mounted/common/40grub2

@@ -2,17 +2,27 @@

 . /usr/share/os-prober/common.sh

 set -e

+# add support for btrfs with no separate /boot

+# that is, rootsv = bootsv

 partition="$1"

 bootpart="$2"

 mpoint="$3"

 type="$4"

+rootsv="$5"

+bootsv="$6"

 found_item=0

 entry_result () {

+	if [ "x$type" = "xbtrfs" -a "$rootsv" = "$bootsv" ]; then

+		# trim off the leading subvol

+		kernelfile=$(echo "$kernel" | cut -d '/' -f 2- | cut -d '/' -f 2-)

+	else

+		kernelfile=$kernel

+	fi

 	if [ "$ignore_item" = 0 ] && \

 	   [ -n "$kernel" ] && \

-	   [ -e "$mpoint/$kernel" ]; then

+	   [ -e "$mpoint/$kernelfile" ]; then

 		result "$rootpart:$bootpart:$title:$kernel:$initrd:$parameters"

 		found_item=1

 	fi

diff --git a/os-prober b/os-prober

index 99ede8e..ca8f5ab 100755

--- a/os-prober

+++ b/os-prober

@@ -64,9 +64,12 @@ partitions () {

 	# Also detect OSes on LVM volumes (assumes LVM is active)

 	if type lvs >/dev/null 2>&1; then

-		echo "$(LVM_SUPPRESS_FD_WARNINGS=1 log_output lvs --noheadings --separator : -o vg_name,lv_name |

+		echo "$(LVM_SUPPRESS_FD_WARNINGS=1 log_output lvs --noheadings --separator : -o vg_name,lv_name 2>/dev/null |

 			sed "s|-|--|g;s|^[[:space:]]*\(.*\):\(.*\)$|/dev/mapper/\1-\2|")"

 	fi

+

+	# now lets make sure we got all of the btrfs partitions and disks

+	blkid | grep btrfs | cut -d ':' -f 1

 }

 parse_proc_swaps () {

@@ -124,6 +127,8 @@ if [ -f /proc/mdstat ] ; then

 	grep "^md" /proc/mdstat | cut -d: -f2- | parse_proc_mdstat >"$OS_PROBER_TMP/raided-map" || true

 fi

+: >"$OS_PROBER_TMP/btrfs-vols"

+

 for partition in $(partitions); do

 	if ! mapped="$(mapdevfs "$partition")"; then

 		log "Device '$partition' does not exist; skipping"

@@ -142,7 +147,26 @@ for partition in $(partitions); do

 		continue

 	fi

-	if ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map" ; then

+	# do btrfs processing here; both mounted and unmounted will

+	# be handled by 50mounted-tests so we can do a subvol only once.

+	type=$(blkid -o value -s TYPE $mapped)

+	if [ "$type" = btrfs ]; then

+		uuid=$(blkid -o value -s UUID $mapped)

+		if grep -q "^$uuid" "$OS_PROBER_TMP/btrfs-vols" ; then

+			continue

+		fi

+		debug "btrfs volume uuid=$uuid partition=$partition"

+		echo "$uuid" >>"$OS_PROBER_TMP/btrfs-vols"

+		test="/usr/lib/os-probes/50mounted-tests"

+		if [ -f "$test" ] && [ -x "$test" ]; then

+			debug "running $test on btrfs $partition"

+			if "$test" btrfs "$uuid" "$partition"; then

+				debug "os detected by $test"

+		   		continue

+			fi

+		fi

+

+	elif ! grep -q "^$mapped " "$OS_PROBER_TMP/mounted-map" ; then

 		for test in /usr/lib/os-probes/*; do

 			if [ -f "$test" ] && [ -x "$test" ]; then

 				debug "running $test on $partition"

diff --git a/os-probes/common/50mounted-tests b/os-probes/common/50mounted-tests

index 561163b..751999a 100755

--- a/os-probes/common/50mounted-tests

+++ b/os-probes/common/50mounted-tests

@@ -1,20 +1,36 @@

 #!/bin/sh

 # Sub-tests that require a mounted partition.

 set -e

-partition="$1"

 . /usr/share/os-prober/common.sh

-types="$(fs_type "$partition")" || types=NOT-DETECTED

+if [ "x$1" = xbtrfs ]; then

+	types=btrfs

+	if [ -z "$2" -o -z "$3" ]; then

+		debug "missing btrfs parameters, exiting"

+		exit 1

+	fi

+	UUID="$2"

+	BTRFSDEV="$3"

+else

+	partition="$1"

+	types="$(fs_type "$partition")" || types=NOT-DETECTED

+fi

+

 if [ "$types" = NOT-DETECTED ]; then

 	debug "$1 type not recognised; skipping"

-	exit 0

+	exit 1

+elif [ "x$types" = "x" ]; then

+	exit 1

+elif [ "$types" = LVM2_member ]; then

+	debug "skipping LVM2 Volume Group on $partition"

+	exit 1

 elif [ "$types" = swap ]; then

 	debug "$1 is a swap partition; skipping"

-	exit 0

+	exit 1

 elif [ "$types" = crypto_LUKS ]; then

 	debug "$1 is a LUKS partition; skipping"

-	exit 0

+	exit 1

 elif [ "$types" = ntfs ]; then

 	if type ntfs-3g >/dev/null 2>&1; then

 		types='ntfs-3g ntfs'

@@ -23,7 +39,7 @@ elif [ -z "$types" ]; then

 	if type cryptsetup >/dev/null 2>&1 && \

 	   cryptsetup luksDump "$partition" >/dev/null 2>&1; then

 		debug "$1 is a LUKS partition; skipping"

-		exit 0

+		exit 1

 	fi

 	for type in $(grep -v nodev /proc/filesystems); do

 		# hfsplus filesystems are mountable as hfs. Try hfs last so

@@ -46,6 +62,76 @@ if [ ! -d "$tmpmnt" ]; then

 fi

 mounted=

+

+# all btrfs processing here.  Handle both unmounted and

+# mounted subvolumes.

+if [ "$types" = btrfs ]; then

+	partition="$BTRFSDEV"

+	debug "begin btrfs processing for $UUID"

+	# note that the btrfs volume must not be mounted ro

+	if mount -t btrfs -U "$UUID" "$tmpmnt"  2>/dev/null; then

+		debug "btrfs volume $UUID mounted"

+	else

+		warn "cannot mount btrfs volume $UUID, exiting"

+		rmdir "$tmpmnt" || true

+		exit 1

+	fi

+	# besides regular subvols, get ro and snapshot so thet can be excluded

+        subvols=$(btrfs subvolume list "$tmpmnt" | cut -d ' ' -f 9)

+        rosubvols=$(btrfs subvolume list -r "$tmpmnt" | cut -d ' ' -f 9)

+        sssubvols=$(btrfs subvolume list -s "$tmpmnt" | cut -d ' ' -f 9)

+        if ! umount "$tmpmnt"; then

+            warn "failed to umount btrfs volume on $tmpmnt"

+            rmdir "$tmpmnt" || true

+            exit 1

+        fi

+	if [ -z "$subvols" ]; then

+		debug "no subvols found on btrfs volume $UUID"

+		exit 1

+	fi

+	found=

+        for subvol in $subvols; do

+		debug "begin btrfs processing for $UUID subvol=$subvol"

+		if echo "$rosubvols" | grep -q -x "$subvol"; then

+			continue

+		fi

+		if echo "$sssubvols" | grep -q -x "$subvol"; then

+			continue

+		fi

+		mounted=

+		mpoint="$(grep btrfs /proc/self/mountinfo | grep "$partition " | grep "/$subvol " | cut -d ' ' -f 5)"

+		if [ -n "$mpoint" ]; then

+			if [ "x$mpoint" = "x/" ]; then

+				continue # this is the root for the running system

+			fi

+			mounted=1

+		else

+			# again, do not mount btrfs ro

+			mount -t btrfs -o subvol="$subvol" -U "$UUID" "$tmpmnt"

+			mpoint="$tmpmnt"

+		fi

+		test="/usr/lib/os-probes/mounted/90linux-distro"

+		if [ -f "$test" ] && [ -x "$test" ]; then

+			debug "running subtest $test"

+			if "$test" "$partition" "$mpoint" btrfs "UUID=$UUID" "subvol=$subvol"; then

+				debug "os found by subtest $test on subvol $subvol"

+				found=1

+			fi

+		fi

+		if [ -z "$mounted" ]; then

+			if ! umount "$tmpmnt"; then

+			    warn "failed to umount $tmpmnt"

+			fi

+		fi

+	done

+	rmdir "$tmpmnt" || true

+	if [ "$found" ]; then

+		exit 0

+	else

+		exit 1

+	fi

+fi

+

 if type grub-mount >/dev/null 2>&1 && \

    type grub-probe >/dev/null 2>&1 && \

    grub-mount "$partition" "$tmpmnt" 2>/dev/null; then

diff --git a/os-probes/mounted/common/90linux-distro b/os-probes/mounted/common/90linux-distro

index 583a9ec..6b03c7a 100755

--- a/os-probes/mounted/common/90linux-distro

+++ b/os-probes/mounted/common/90linux-distro

@@ -7,6 +7,8 @@ set -e

 partition="$1"

 dir="$2"

 type="$3"

+uuid="$4"

+subvol="$5"

 # This test is inaccurate, but given separate / and /boot partitions and the

 # fact that only some architectures have ld-linux.so, I can't see anything

@@ -131,7 +133,11 @@ if (ls "$dir"/lib*/ld*.so*  && [ -d "$dir/boot" ] || ls "$dir"/usr/lib*/ld*.so*)

 	fi

         label="$(count_next_label "$short")"

-	result "$partition:$long:$label:linux"

+	if [ "x$type" = "xbtrfs" -a "x$uuid" != "x" -a "x$subvol" != "x" ]; then

+		result "$partition:$long:$label:linux:$type:$uuid:$subvol"

+	else

+		result "$partition:$long:$label:linux"

+	fi

 	exit 0

 else

 	exit 1

-- 

2.5.5