File SLE12-SP1-btrfs.patch of Package rear1172a.32115
diff -rp -U17 rear-1.17.2/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_filesystem_code.sh rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_filesystem_code.sh
--- rear-1.17.2/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_filesystem_code.sh 2015-06-25 09:07:56.000000000 +0200
+++ rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_filesystem_code.sh 2015-10-02 12:33:46.000000000 +0200
@@ -1,41 +1,58 @@
# code to mount a file system
# 13_mount_filesystem_code.sh contains the generic function 'mount_fs'
# each distro may overrule the 'mount_fs' function with its proper way to do it
# especially the case for btrfs related file systems
mount_fs() {
Log "Begin mount_fs( $@ )"
local fs device mp fstype uuid label options
## mp: mount point
read fs device mp fstype uuid label options < <(grep "^fs.* ${1#fs:} " "$LAYOUT_FILE")
label=${label#label=}
uuid=${uuid#uuid=}
# Extract mount options.
local option mountopts
+ # An input line could look like this (an example from SLES12-SP1):
+ # fs /dev/sda2 / btrfs uuid=a2b2c3 label= options=rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot
+ # which means by the above 'read' the variable (that is unfortunately) named 'options' gets the
+ # value 'options=rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot'
+ # i.e. options='options=rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot'
for option in $options ; do
- name=${option%%=*} # options can contain more '=' signs
- value=${option#*=}
+ name=${option%%=*} # an option can contain more '=' signs (see the above example value)
+ value=${option#*=} # therefore split the name from the actual value at the leftmost '='
case $name in
(options)
### Do not mount nodev, as chrooting later on would fail.
- mountopts=${value//nodev/dev}
+ value=${value//nodev/dev}
+ # btrfs mount options like subvolid=259 or subvol=/@/.snapshots/1/snapshot
+ # from the old system cannot work here for recovery because btrfs subvolumes
+ # are not yet created (and when created their subvolid is likely different)
+ # so that those mount options are removed here. All btrfs subvolume handling
+ # happens in the btrfs_subvolumes_setup function in 13_include_mount_subvolumes_code.sh
+ # First add a comma at the end so that it is easier to remove a mount option at the end:
+ value=${value/%/,}
+ # Remove all subvolid= and subvol= mount options (the extglob shell option is enabled in rear):
+ value=${value//subvolid=*([^,]),/}
+ value=${value//subvol=*([^,]),/}
+ # Remove all commas at the end:
+ mountopts=${value/%,/}
;;
esac
done
if [ -n "$mountopts" ] ; then
mountopts="-o $mountopts"
fi
echo "LogPrint \"Mounting filesystem $mp\"" >> "$LAYOUT_CODE"
case $fstype in
(btrfs)
# The following commands are basically the same as in the default/fallback case.
# The explicite case for btrfs is only there to be prepared for special adaptions for btrfs related file systems.
# Because the btrfs filesystem was created anew just before by the create_fs function in 13_include_filesystem_code.sh
# the code here mounts the whole btrfs filesystem because by default when creating a btrfs filesystem
# its top-level/root subvolume is the btrfs default subvolume which gets mounted when no other subvolume is specified.
diff -rp -U17 rear-1.17.2/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_subvolumes_code.sh rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_subvolumes_code.sh
--- rear-1.17.2/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_subvolumes_code.sh 2015-06-08 09:50:38.000000000 +0200
+++ rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/prepare/GNU/Linux/13_include_mount_subvolumes_code.sh 2015-10-16 12:09:06.000000000 +0200
@@ -19,206 +19,309 @@ btrfs_subvolumes_setup() {
# where $device is the device node where the filesystem was already created by 13_include_filesystem_code.sh
# (usually a harddisk partition like e.g. /dev/sda1):
device=$1
mountpoint=$2
# mountopts are of the form "-o foo,bar,baz" (see 13_include_mount_filesystem_code.sh)
# which means $3 is '-o' and 'foo,bar,baz' is $4:
mountopts="$3 $4"
# Empty device or mountpoint may indicate an error. In this case be verbose and inform the user:
if test -z "$device" -o -z "$mountpoint" ; then
LogPrint "Empty device='$device' or mountpoint='$mountpoint' may indicate an error, skipping btrfs_subvolumes_setup( $@ )."
Log "Return 0 from btrfs_subvolumes_setup( $@ )"
return 0
fi
# FIXME: The following avoids to have '/mnt/local' hardcoded at many places in the code only here.
# The root of the filesysten tree of the to-be-recovered-system in the recovery system should be in a global variable:
recovery_system_root=/mnt/local
###########################################
+ # SLES 12 SP1 special btrfs subvolumes setup detection:
+ SLES12SP1_btrfs_detection_string="@/.snapshots/"
+ if grep "^btrfsdefaultsubvol $device $mountpoint [0-9]* $SLES12SP1_btrfs_detection_string" "$LAYOUT_FILE" ; then
+ info_message="Detected SLES 12 SP1 special btrfs subvolumes setup because the default subvolume path contains '$SLES12SP1_btrfs_detection_string'"
+ Log $info_message
+ echo "# $info_message" >> "$LAYOUT_CODE"
+ # For SLES 12 SP1 a btrfsdefaultsubvol entry in disklayout.conf looks like
+ # btrfsdefaultsubvol /dev/sda2 / 259 @/.snapshots/1/snapshot
+ # where "@/.snapshots/" should be fixed but "1/snapshot" may vary.
+ # This requires special setup because the btrfs default subvolume on SLES 12 SP1
+ # is not a normal btrfs subvolume (as it was on SLES 12 (without SP1))
+ # but on SLES 12 SP1 it is a snapper controlled btrfs snapshot subvolume, see
+ # https://github.com/rear/rear/issues/556
+ # https://fate.suse.com/318701 (SUSE internal feature request)
+ # https://bugzilla.suse.com/show_bug.cgi?id=946006 (SUSE internal issue)
+ SLES12SP1_btrfs_subvolumes_setup="yes"
+ # Because that very special btrfs default subvolume on SLES 12 SP1
+ # has to be controlled by snapper it must be set up by snapper
+ # which means that snapper is needed in the rear recovery system.
+ # For this special setup during installation a special SUSE tool
+ # /usr/lib/snapper/installation-helper is used:
+ SLES12SP1_installation_helper_executable="/usr/lib/snapper/installation-helper"
+ # What "snapper/installation-helper --step 1" basically does is
+ # creating a snapshot of the first root filesystem
+ # where the first root filesystem must have the btrfs subvolume '@' mounted at '/'
+ # which means the btrfs subvolume '@' must be the initial btrfs default subvolume:
+ SLES12SP1_initial_default_subvolume_path="@"
+ fi
+ ###########################################
# Btrfs snapshot subvolumes handling:
# Remember all btrfs snapshot subvolumes to exclude them when mounting all btrfs normal subvolumes below.
# The btrfs snapshot subvolumes entries that are created by 23_filesystem_layout.sh
# are deactivated (as '#btrfssnapshotsubvol ...') in the LAYOUT_FILE (disklayout.conf).
# When there are active btrfs snapshot subvolumes entries, the user has manually
# activated them (as 'btrfssnapshotsubvol ...') in the LAYOUT_FILE (disklayout.conf).
# Because any btrfssnapshotsubvol entries are needed to exclude all btrfs snapshot subvolumes
# 'grep "btrfssnapshotsubvol ..." ... | sed ...' is used.
while read keyword dummy dummy dummy subvolume_path junk ; do
if test -z "$subvolume_path" ; then
continue
fi
# When there is a non-empty subvolume_path, btrfs snapshot subvolume handling is needed:
Log "Handling snapshot subvolume $subvolume_path for $device at $mountpoint"
# Remember btrfs snapshot subvolumes to exclude them when mounting all btrfs normal subvolumes below:
snapshot_subvolumes_devices_and_paths="$snapshot_subvolumes_devices_and_paths $device,$subvolume_path"
# Be verbose if there are active btrfs snapshot subvolumes entries (snapshot subvolumes cannot be recreated).
# In this case inform the user that nothing can be done for activated snapshot subvolumes entries:
if test "btrfssnapshotsubvol" = "$keyword" ; then
info_message="It is not possible to recreate btrfs snapshot subvolumes, skipping $subvolume_path on $device at $mountpoint"
LogPrint $info_message
echo "# $info_message" >> "$LAYOUT_CODE"
fi
done < <( grep "btrfssnapshotsubvol $device $mountpoint " "$LAYOUT_FILE" | sed -e 's/.*#.*btrfssnapshotsubvol/#btrfssnapshotsubvol/' )
###########################################
# Btrfs normal subvolumes setup:
# Create the normal btrfs subvolumes before the btrfs default subvolume setup
# because currently the whole btrfs filesystem (i.e. its top-level/root subvolume) is mounted at the mountpoint
# so that currently normal btrfs subvolumes can be created using the subvolume path relative to the btrfs toplevel/root subvolume
# and that subvolume path relative to the btrfs toplevel/root subvolume is stored in the LAYOUT_FILE.
# In contrast after the btrfs default subvolume setup only the btrfs filesystem default subvolume is mounted at the mountpoint and
# then it would be no longer possible to create btrfs subvolumes with the subvolume path that is stored in the LAYOUT_FILE.
# In particular a special btrfs default subvolume (i.e. when the btrfs default subvolume is not the toplevel/root subvolume)
- # is also listed as a normal subvolume so that also the subvolume that is later used as default subvolume is hereby created.
+ # is also listed as a normal subvolume so that also the subvolume that is later used as default subvolume is hereby created
+ # provided the btrfs default subvolume is not a btrfs snapshot subvolume as in SLES 12 SP1 - but not in SLES 12 (without SP1):
while read dummy dummy dummy dummy subvolume_path junk ; do
# Empty subvolume_path may indicate an error. In this case be verbose and inform the user:
if test -z "$subvolume_path" ; then
LogPrint "btrfsnormalsubvol entry with empty subvolume_path for $device at $mountpoint may indicate an error, skipping subvolume setup for it."
continue
fi
+ # In case of SLES 12 SP1 special btrfs subvolumes setup
+ # skip setup of the normal btrfs subvolume '@/.snapshots' because
+ # that one will be created by "snapper/installation-helper --step 1"
+ # which fails if it already exists:
+ if test -n "$SLES12SP1_btrfs_subvolumes_setup" ; then
+ test "$subvolume_path" = "@/.snapshots" && continue
+ fi
# When there is a non-empty subvolume_path, btrfs normal subvolume setup is needed:
Log "Setup normal subvolume $subvolume_path for $device at $mountpoint"
# E.g. for 'btrfs subvolume create /foo/bar/subvol' the directory path /foo/bar/ must already exist
# but 'subvol' must not exist because 'btrfs subvolume create' creates the subvolume 'subvol' itself.
# When 'subvol' already exists (e.g. as normal directory), it fails with ERROR: '/foo/bar/subvol' exists.
subvolume_directory_path=${subvolume_path%/*}
if test "$subvolume_directory_path" = "$subvolume_path" ; then
# When subvolume_path is only plain 'mysubvol' then also subvolume_directory_path becomes 'mysubvol'
# but 'mysubvol' must not be made as a normal directory by 'mkdir' below:
subvolume_directory_path=""
fi
recovery_system_mountpoint=$recovery_system_root$mountpoint
info_message="Creating normal btrfs subvolume $subvolume_path on $device at $mountpoint"
Log $info_message
(
echo "# $info_message"
if test -n "$subvolume_directory_path" ; then
# Test in the recovery system if the directory path already exists to avoid that
# useless 'mkdir -p' commands are run which look confusing in the "rear recover" log
# regardless that 'mkdir -p' does nothing when its argument already exists:
echo "if ! test -d $recovery_system_mountpoint/$subvolume_directory_path ; then"
echo " mkdir -p $recovery_system_mountpoint/$subvolume_directory_path"
echo "fi"
fi
echo "btrfs subvolume create $recovery_system_mountpoint/$subvolume_path"
) >> "$LAYOUT_CODE"
+ # Btrfs subvolumes 'no copy on write' attribute setup:
+ if grep -q "^btrfsnocopyonwrite $subvolume_path\$" "$LAYOUT_FILE" ; then
+ info_message="Setting 'no copy on write' attribute for subvolume $subvolume_path"
+ Log $info_message
+ (
+ echo "# $info_message"
+ echo "chattr +C $recovery_system_mountpoint/$subvolume_path"
+ ) >> "$LAYOUT_CODE"
+ fi
done < <( grep "^btrfsnormalsubvol $device $mountpoint " "$LAYOUT_FILE" )
###########################################
# Btrfs default subvolume setup:
- # There is exactly one default subvolume for one btrfs filesystem on one specific device (usually a harddisk partition like e.g. /dev/sda1):
+ # No outer 'while read ...' loop because there is exactly one default subvolume for one btrfs filesystem
+ # on one specific device (usually a harddisk partition like e.g. /dev/sda1):
read dummy dummy dummy dummy subvolume_path junk < <( grep "^btrfsdefaultsubvol $device $mountpoint " "$LAYOUT_FILE" )
# Artificial 'for' clause that is run only once to be able to 'continue' in the same syntactical way as in the 'while' loops
# (because the 'for' loop is run only once 'continue' is the same as 'break'):
for dummy in "once" ; do
# Empty subvolume_path may indicate an error. In this case be verbose and inform the user:
if test -z "$subvolume_path" ; then
LogPrint "btrfsdefaultsubvol entry with empty subvolume_path for $device at $mountpoint may indicate an error, skipping default subvolume setup for it."
continue
fi
# When there is a non-empty subvolume_path, btrfs default subvolume setup is needed:
Log "Setup default subvolume $subvolume_path for $device at $mountpoint"
# Remember the btrfs default subvolume on that specific device which is needed when mounting all btrfs normal subvolumes below
# (also needed when the default subvolume path is "/" to avoid that it gets remounted when mounting normal subvolumes below):
default_subvolume_path="$subvolume_path"
# When subvolume_path is "/", the default for the btrfs default subvolume is used
# (i.e. the btrfs default subvolume is the toplevel/root subvolume):
if test "/" = "$subvolume_path" ; then
info_message="No special btrfs default subvolume is used on $device at $mountpoint, no default subvolume setup needed"
Log $info_message
echo "# $info_message" >> "$LAYOUT_CODE"
continue
fi
- # When in the original system the btrfs filesystem had a special different default subvolume,
+ # When in the original system the btrfs filesystem had a special different default subvolume
+ # (i.e. when the btrfs default subvolume is not the toplevel/root subvolume), then
# that different subvolume needs to be set to be the default subvolume:
recovery_system_mountpoint=$recovery_system_root$mountpoint
Log "Setting $subvolume_path as btrfs default subvolume for $device at $mountpoint"
- (
- echo "# Begin btrfs default subvolume setup on $device at $mountpoint"
- echo "# Making the $subvolume_path subvolume the default subvolume"
- echo "# Get the ID of the $subvolume_path subvolume"
- echo "subvolumeID=\$( btrfs subvolume list -a $recovery_system_mountpoint | sed -e 's/<FS_TREE>\///' | grep ' $subvolume_path\$' | tr -s '[:blank:]' ' ' | cut -d ' ' -f 2 )"
- echo "# Set the $subvolume_path subvolume as default subvolume using its subvolume ID"
- echo "btrfs subvolume set-default \$subvolumeID $recovery_system_mountpoint"
- ) >> "$LAYOUT_CODE"
+ if test -n "$SLES12SP1_btrfs_subvolumes_setup" ; then
+ (
+ echo "# Begin btrfs default subvolume setup on $device at $mountpoint"
+ echo "# Doing special SLES 12 SP1 btrfs default snapper snapshot subvolume setup"
+ echo "# because the default subvolume path '$subvolume_path' contains '@/.snapshots/'"
+ echo "# Making the $SLES12SP1_initial_default_subvolume_path subvolume the initial default subvolume"
+ echo "# Get the ID of the $initial_default_subvolume_path subvolume"
+ echo "subvolumeID=\$( btrfs subvolume list -a $recovery_system_mountpoint | sed -e 's/<FS_TREE>\///' | grep ' $SLES12SP1_initial_default_subvolume_path\$' | tr -s '[:blank:]' ' ' | cut -d ' ' -f 2 )"
+ echo "# Set the $SLES12SP1_initial_default_subvolume_path subvolume as initial default subvolume using its subvolume ID"
+ echo "btrfs subvolume set-default \$subvolumeID $recovery_system_mountpoint"
+ echo "# Begin step 1 of special SLES 12 SP1 btrfs default snapper snapshot subvolume setup"
+ echo "umount $recovery_system_mountpoint"
+ echo "# Configuring snapper for root filesystem - step 1:"
+ echo "# - temporarily mounting device"
+ echo "# - copying/modifying config-file"
+ echo "# - creating filesystem config"
+ echo "# - creating snapshot of first root filesystem"
+ echo "# - setting default subvolume"
+ echo "if test -x $SLES12SP1_installation_helper_executable"
+ echo "then $SLES12SP1_installation_helper_executable --step 1 --device $device --description 'first root filesystem'"
+ echo "else LogPrint '$SLES12SP1_installation_helper_executable not executable may indicate an error with btrfs default subvolume setup for $subvolume_path on $device'"
+ echo "fi"
+ echo " mount -t btrfs -o subvolid=0 $mountopts $device $recovery_system_mountpoint"
+ echo "# End step 1 of special SLES 12 SP1 btrfs default snapper snapshot subvolume setup"
+ ) >> "$LAYOUT_CODE"
+ else
+ (
+ echo "# Begin btrfs default subvolume setup on $device at $mountpoint"
+ echo "# Making the $subvolume_path subvolume the default subvolume"
+ echo "# Get the ID of the $subvolume_path subvolume"
+ echo "subvolumeID=\$( btrfs subvolume list -a $recovery_system_mountpoint | sed -e 's/<FS_TREE>\///' | grep ' $subvolume_path\$' | tr -s '[:blank:]' ' ' | cut -d ' ' -f 2 )"
+ echo "# Set the $subvolume_path subvolume as default subvolume using its subvolume ID"
+ echo "btrfs subvolume set-default \$subvolumeID $recovery_system_mountpoint"
+ ) >> "$LAYOUT_CODE"
+ fi
# When the btrfs filesystem has a special default subvolume (one that is not the toplevel/root subvolume)
# then a reasonable assumption is that this one was mounted in the original system and not something else.
# FIXME: It is possible that the admin has actually mounted something else in his original system
# which would result a wrong recovery because currently such an awkward setup is not supported.
# Under the above assumption the btrfs filesystem needs to be umonted and mounted again so that
# the special default subvolume gets mounted in the recovery system at /mnt/local$mountpoint.
Log "Remounting the btrfs default subvolume $subvolume_path for $device at $mountpoint"
(
echo "# Remounting the $subvolume_path default subvolume at $recovery_system_mountpoint"
echo "umount $recovery_system_mountpoint"
echo "mount -t btrfs $mountopts $device $recovery_system_mountpoint"
echo "# End btrfs default subvolume setup on $device at $mountpoint"
) >> "$LAYOUT_CODE"
done
###########################################
# Mounting all btrfs normal subvolumes:
# After the btrfs default subvolume setup now the btrfs default subvolume is mounted and then it is possible
# to mount the other btrfs normal subvolumes at their mountpoints in the tree of the mounted filesystems:
while read dummy dummy subvolume_mountpoint subvolume_mount_options subvolume_path junk ; do
# Empty subvolume_mountpoint or subvolume_mount_options or subvolume_path may indicate an error.
# E.g. missing subvolume mount options result that the subvolume path is read into subvolume_mount_options and subvolume_path becomes empty.
# Therefore be verbose and inform the user:
if test -z "$subvolume_mountpoint" -o -z "$subvolume_mount_options" -o -z "$subvolume_path" ; then
LogPrint "btrfsmountedsubvol entry for $device where subvolume_mountpoint='$subvolume_mountpoint' or subvolume_mount_options='$subvolume_mount_options' or subvolume_path='$subvolume_path' is empty may indicate an error, skipping mounting it."
continue
fi
# When there are non-empty values, mounting normal subvolume is needed:
Log "Mounting normal subvolume $subvolume_path at $subvolume_mountpoint for $device"
+ # btrfs mount options like subvolid=259 or subvol=/@/.snapshots/1/snapshot
+ # from the old system cannot work here or are not needed here for recovery
+ # because for new created btrfs subvolumes their subvolid is likely different
+ # and the subvol=... value is already explicitly available via subvolume_path
+ # so that those mount options are removed here:
+ # First add a comma at the end so that it is easier to remove a mount option at the end:
+ subvolume_mount_options=${subvolume_mount_options/%/,}
+ # Remove all subvolid= and subvol= mount options (the extglob shell option is enabled in rear):
+ subvolume_mount_options=${subvolume_mount_options//subvolid=*([^,]),/}
+ subvolume_mount_options=${subvolume_mount_options//subvol=*([^,]),/}
+ # Remove all commas at the end:
+ subvolume_mount_options=${subvolume_mount_options/%,/}
# Do not mount btrfs snapshot subvolumes:
for snapshot_subvolume_device_and_path in $snapshot_subvolumes_devices_and_paths ; do
# Assume $snapshot_subvolume_device_and_path is "/dev/sdX99,my/subvolume,path" then split
# at the first comma because device nodes (e.g. /dev/sdX99) do not contain a comma
# but a subvolume path may contain a comma (e.g. my/subvolume,path).
# If a subvolume path contains space or tab characters it will break here
# because space tab and newline are standard bash internal field separators ($IFS)
# so that admins who use such characters for their subvolume paths get hereby
# an exercise in using fail-safe names and/or how to enhance standard bash scripts:
snapshot_subvolume_device=${snapshot_subvolume_device_and_path%%,*}
snapshot_subvolume_path=${snapshot_subvolume_device_and_path#*,}
if test "$device" = "$snapshot_subvolume_device" -a "$subvolume_path" = "$snapshot_subvolume_path" ; then
info_message="It is not possible to recreate btrfs snapshot subvolumes, skipping mounting $subvolume_path on $device at $subvolume_mountpoint"
Log $info_message
echo "# $info_message" >> "$LAYOUT_CODE"
# If one snapshot_subvolume_device_and_path matches,
# continue with the next btrfsmountedsubvol line from the LAYOUT_FILE
# (i.e. continue with the while loop which is the 2th enclosing loop):
continue 2
fi
done
recovery_system_mountpoint=$recovery_system_root$subvolume_mountpoint
# Remounting is needed when at the '/' mountpoint not the btrfs default subvolume is mounted:
# On Fedora 21 what is mounted at the root of the filesystem tree (i.e. at the '/' mountpoint)
# is not the btrfs default subvolume (the default subvolume is the toplevel/root subvolume).
# On Fedora 21 there is a btrfs subvolume "root" which is mounted at the '/' mountpoint.
# I (jsmeix@suse.de) am not a btrfs expert but from my point of view it looks like
# a misconfiguration (a.k.a. bug) in Fedora 21 how they set up btrfs. I think Fedora
- # should specify as btrfs default subvolume what is mounted at the '/' mountpoint.
- # Regardless if it is really a misconfiguration or not I like to have rear working fail-safe
- # because an admin could manually create such an awkward btrfs setup.
+ # should specify as btrfs default subvolume what is mounted by default at the '/' mountpoint.
+ # On the other hand I noticed an openSUSE user who presented arguments that
+ # the btrfs default subvolume setting only belongs to the user and
+ # should not be used by the system to specify what is mounted by default,
+ # see what Chris Murphy wrote on the "Default btrfs subvolume after a rollback"
+ # and "systemd, btrfs, /var/lib/machines" mail threads on opensuse-factory@opensuse.org
+ # http://lists.opensuse.org/opensuse-factory/2015-07/msg00517.html
+ # http://lists.opensuse.org/opensuse-factory/2015-07/msg00591.html
+ # and his GitHub snapper issue and openSUSE feature request
+ # "snapper improperly usurps control of the default subvolume from the user"
+ # https://github.com/openSUSE/snapper/issues/178
+ # https://features.opensuse.org/319292
+ # Regardless who or what is right or wrong here I like to have rear working fail-safe
+ # because an admin could manually create any kind of awkward btrfs setup.
# Therefore remounting is needed when the subvolume_mountpoint is '/'
# but the subvolume_path is neither '/' nor the default subvolume.
# Examples: disklayout.conf contains
# on openSUSE 13.2 at '/' the default subvolume which is the root subvolume (ID 5 '/') is mounted:
# btrfsdefaultsubvol /dev/sda2 / 5 /
# btrfsmountedsubvol /dev/sda2 / rw,relatime,space_cache /
# on SLES 12 at '/' the default subvolume '@' is mounted:
# btrfsdefaultsubvol /dev/sda2 / 257 @
# btrfsmountedsubvol /dev/sda2 / rw,relatime,space_cache @
+ # on SLES 12 SP1 at '/' the default subvolume '@/.snapshots/1/snapshot' is mounted:
+ # btrfsdefaultsubvol /dev/sda2 / 259 @/.snapshots/1/snapshot
+ # #btrfssnapshotsubvol /dev/sda2 / 259 @/.snapshots/1/snapshot
+ # btrfsnormalsubvol /dev/sda2 / 258 @/.snapshots
+ # btrfsmountedsubvol /dev/sda2 / rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot @/.snapshots/1/snapshot
# on Fedora 21 at '/' not the default subvolume which is the root subvolume (ID 5 '/') but the subvolume 'root' is mounted:
# btrfsdefaultsubvol /dev/sda3 / 5 /
# btrfsmountedsubvol /dev/sda3 / rw,relatime,seclabel,space_cache root
# FIXME: Currently only for the mountpoint '/' there is this special handling.
# In general the subvolume_mountpoint could be anything.
# For example for a second disk /dev/sdb1 the disklayout.conf file could contain those entries:
# btrfsdefaultsubvol /dev/sdb1 /data 5 /
# btrfsmountedsubvol /dev/sdb1 /data rw,relatime,seclabel,space_cache datasubvol
# This would mean for /dev/sdb1 what is mounted at its mountpoint /data
# is not its btrfs default subvolume but the btrfs subvolume "datasubvol".
# Currently such a setup is not supported for mountpoints other than '/'.
if test '/' = "$subvolume_mountpoint" ; then
# No remounting needed when the subvolume_path is the default_subvolume_path for this device
# because then the default subvolume is already mounted by the "Btrfs default subvolume setup" above:
if test "$subvolume_path" = "$default_subvolume_path" ; then
Log "On $device btrfs default subvolume $default_subvolume_path already mounted at $subvolume_mountpoint, no remounting needed"
continue
diff -rp -U17 rear-1.17.2/usr/share/rear/layout/save/GNU/Linux/23_filesystem_layout.sh rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/save/GNU/Linux/23_filesystem_layout.sh
--- rear-1.17.2/usr/share/rear/layout/save/GNU/Linux/23_filesystem_layout.sh 2015-06-25 09:07:56.000000000 +0200
+++ rear-1.17.2.SLE12-SP1-btrfs/usr/share/rear/layout/save/GNU/Linux/23_filesystem_layout.sh 2015-10-16 12:06:18.000000000 +0200
@@ -256,23 +256,49 @@ read_filesystems_command="$read_filesyst
if test -z "$btrfs_subvolume_path" ; then
# When btrfs_subvolume_path is empty (in particular when the traditional mount command is used)
# try to find the mountpoint in /etc/fstab and try to read the subvol=... option value if exists
# (using subvolid=... can fail because the subvolume ID can be different during system recovery).
# Because both "mount ... -o subvol=/path/to/subvolume" and "mount ... -o subvol=path/to/subvolume" work
# the subvolume path can be specified with or without leading '/':
btrfs_subvolume_path=$( grep " $subvolume_mountpoint btrfs " /etc/fstab | grep -o 'subvol=[^ ]*' | cut -s -d '=' -f 2 )
fi
# Remove leading '/' from btrfs_subvolume_path (except it is only '/') to have same syntax for all entries and
# without leading '/' is more clear that it is not an absolute path in the currently mounted tree of filesystems
# instead the subvolume path is relative to the toplevel/root subvolume of the particular btrfs filesystem
# (i.e. a subvolume path is an absolute path in the particular btrfs filesystem)
# see https://btrfs.wiki.kernel.org/index.php/Mount_options
test "/" != "$btrfs_subvolume_path" && btrfs_subvolume_path=${btrfs_subvolume_path#/}
echo "btrfsmountedsubvol $device $subvolume_mountpoint $mount_options $btrfs_subvolume_path"
fi
done < <( eval $read_mounted_btrfs_subvolumes_command )
+ ########################################
+ # No copy on write attributes of mounted btrfs subvolumes:
+ echo "# Mounted btrfs subvolumes that have the 'no copy on write' attribute set."
+ echo "# Format: btrfsnocopyonwrite <btrfs_subvolume_path>"
+ lsattr_command="$( type -P lsattr )"
+ if test -x "$lsattr_command" -a -x "$findmnt_command" ; then
+ for subvolume_mountpoint in $( $findmnt_command -nrv -o TARGET -t btrfs ) ; do
+ # The 'no copy on write' attribute is shown as 'C' in the lsattr output (see "man chattr"):
+ if $lsattr_command -d $subvolume_mountpoint | cut -d ' ' -f 1 | grep -q 'C' ; then
+ btrfs_subvolume_path=$( $findmnt_command -nrv -o FSROOT $subvolume_mountpoint )
+ # Remove leading '/' from btrfs_subvolume_path (except it is only '/') to have same syntax for all entries and
+ # without leading '/' is more clear that it is not an absolute path in the currently mounted tree of filesystems
+ # instead the subvolume path is relative to the toplevel/root subvolume of the particular btrfs filesystem
+ # (i.e. a subvolume path is an absolute path in the particular btrfs filesystem)
+ # see https://btrfs.wiki.kernel.org/index.php/Mount_options
+ test "/" != "$btrfs_subvolume_path" && btrfs_subvolume_path=${btrfs_subvolume_path#/}
+ if test -n "btrfs_subvolume_path" ; then
+ echo "btrfsnocopyonwrite $btrfs_subvolume_path"
+ else
+ echo "# $subvolume_mountpoint has the 'no copy on write' attribute set but $findmnt_command does not show its btrfs subvolume path"
+ fi
+ fi
+ done
+ else
+ echo "# Attributes cannot be determined because no executable 'lsattr' and/or 'findmnt' command(s) found."
+ fi
fi
) >> $DISKLAYOUT_FILE
# End writing output to DISKLAYOUT_FILE.
Log "End saving filesystem layout"
