| Current File : //usr/local/jetapps/usr/share/rear/layout/prepare/GNU/Linux/133_include_mount_filesystem_code.sh |
# code to mount a file system
# 130_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 mountpoint fstype uuid label attributes
read fs device mountpoint fstype uuid label attributes < <(grep "^fs.* ${1#fs:} " "$LAYOUT_FILE")
label=${label#label=}
uuid=${uuid#uuid=}
# Extract mount options:
local attribute mountopts
# An input line could look like this (an example from SLES12-SP1):
# Format: fs <device> <mountpoint> <fstype> [uuid=<uuid>] [label=<label>] [<attributes>]
# fs /dev/sda2 / btrfs uuid=a2b2c3 label= options=rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot
# For example the attributes variable can contain a value like:
# "reserved_blocks=5% max_mounts=-1 default_mount_options=user_xattr,acl options=rw,relatime,barrier=1,data=ordered"
# I.e. the attributes variable can contain several attributes separated by space each of the form name=value.
for attribute in $attributes ; do
# An attribute can contain more '=' signs (see the above "options=foo,this=that,..." example values)
# therefore split the name from the actual value at the leftmost '='
# (e.g. name="options" value="rw,relatime,space_cache,subvolid=259,subvol=/@/.snapshots/1/snapshot"):
name=${attribute%%=*}
value=${attribute#*=}
# The attribute with name "options" contains the mount options:
case $name in
(options)
# Do not mount nodev, as chrooting later on would fail:
# FIXME: naive approach, will replace any "nodev" inside longer options/values
value=${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_SLES function in 136_include_btrfs_subvolumes_SLES_code.sh
# or in the btrfs_subvolumes_setup_generic function in 135_include_btrfs_subvolumes_generic_code.sh
# Remove all subvolid= and subvol= mount options:
mountopts="$( remove_mount_options_values $value subvolid subvol )"
;;
esac
done
if [ -n "$mountopts" ] ; then
mountopts="-o $mountopts"
fi
echo "LogPrint \"Mounting filesystem $mountpoint\"" >> "$LAYOUT_CODE"
case $fstype in
(btrfs)
# The following commands are basically the same as in the default/fallback case.
# The explicit 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 131_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.
# For a plain btrfs filesystem without subvolumes it is effectively the same as for other filesystems (like ext2/3/4).
(
echo "mkdir -p $TARGET_FS_ROOT$mountpoint"
echo "mount -t btrfs $mountopts $device $TARGET_FS_ROOT$mountpoint"
) >> "$LAYOUT_CODE"
# But btrfs filesystems with subvolumes need a special handling.
# In particular when in the original system the btrfs filesystem had a special different default subvolume,
# that different subvolume needs to be first created, then set to be the default subvolume, and
# finally that btrfs filesystem needs to be unmounted and mounted again so that in the end
# that special different default subvolume is mounted at the mountpoint $TARGET_FS_ROOT$mountpoint.
# All btrfs subvolume handling happens in the btrfs_subvolumes_setup_SLES function in 136_include_btrfs_subvolumes_SLES_code.sh
# or in the btrfs_subvolumes_setup_generic function in 135_include_btrfs_subvolumes_generic_code.sh.
# For a plain btrfs filesystem without subvolumes the btrfs_subvolumes_setup_* functions do nothing.
# Call the right btrfs_subvolumes_setup_* function for the btrfs filesystem that was mounted above via an
# artificial 'for' clause that is run only once to be able to 'continue' with the code after it:
for dummy in "once" ; do
# First of all test what is explicitly specified to be done for particular devices because
# what is explicitly specified for a particular device must be done with highest priority:
if IsInArray "$device" "${BTRFS_SUBVOLUME_GENERIC_SETUP[@]}" ; then
LogPrint "Doing generic btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_GENERIC_SETUP contains $device)"
btrfs_subvolumes_setup_generic $device $mountpoint
continue
fi
if IsInArray "$device" "${BTRFS_SUBVOLUME_SLES_SETUP[@]}" ; then
LogPrint "Doing SLES-like btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_SLES_SETUP contains $device)"
btrfs_subvolumes_setup_SLES $device $mountpoint $mountopts
continue
fi
# Then test what is explicitly specified to be done globally (i.e. for all devices)
# where doing a generic btrfs subvolumes setup has precedence over doing a SLES-like btrfs subvolumes setup so that
# when both BTRFS_SUBVOLUME_GENERIC_SETUP and BTRFS_SUBVOLUME_SLES_SETUP are true, the generic one is done:
if is_true "$BTRFS_SUBVOLUME_GENERIC_SETUP" ; then
LogPrint "Doing generic btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_GENERIC_SETUP true)"
btrfs_subvolumes_setup_generic $device $mountpoint
continue
fi
if is_true "$BTRFS_SUBVOLUME_SLES_SETUP" ; then
LogPrint "Doing SLES-like btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_SLES_SETUP true)"
btrfs_subvolumes_setup_SLES $device $mountpoint $mountopts
continue
fi
# Then test if it is explicitly specified to do nothing at all.
# When both BTRFS_SUBVOLUME_GENERIC_SETUP and BTRFS_SUBVOLUME_SLES_SETUP are explicitly set to false
# no special btrfs subvolumes setup is done which may lead to a falsely recreated system
# but we do what the user has explicitly specified:
if is_false "$BTRFS_SUBVOLUME_GENERIC_SETUP" && is_false "$BTRFS_SUBVOLUME_SLES_SETUP" ; then
LogPrint "Skipping btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_GENERIC_SETUP and BTRFS_SUBVOLUME_SLES_SETUP false)"
continue
fi
# Then test if it is explicitly specified to not do a certain kind of btrfs subvolumes setup
# i.e. the meaning when one kind of btrfs subvolumes setup is set to false is
# that then the other kind of btrfs subvolumes setup should be done
# (unless both are set to false which was already tested before):
if is_false "$BTRFS_SUBVOLUME_GENERIC_SETUP" ; then
LogPrint "Doing SLES-like btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_GENERIC_SETUP false)"
btrfs_subvolumes_setup_SLES $device $mountpoint $mountopts
continue
fi
if is_false "$BTRFS_SUBVOLUME_SLES_SETUP" ; then
LogPrint "Doing generic btrfs subvolumes setup for $device on $mountpoint (BTRFS_SUBVOLUME_SLES_SETUP false)"
btrfs_subvolumes_setup_generic $device $mountpoint
continue
fi
# Final fallback to be backward compatible (btrfs_subvolumes_setup_SLES is the old way) when nothing is specified:
LogPrint "Fallback SLES-like btrfs subvolumes setup for $device on $mountpoint (no match in BTRFS_SUBVOLUME_GENERIC_SETUP or BTRFS_SUBVOLUME_SLES_SETUP)"
btrfs_subvolumes_setup_SLES $device $mountpoint $mountopts
done
;;
(vfat)
# mounting vfat filesystem - avoid using mount options - issue #576
(
echo "mkdir -p $TARGET_FS_ROOT$mountpoint"
echo "mount $device $TARGET_FS_ROOT$mountpoint"
) >> "$LAYOUT_CODE"
;;
(ext2 | ext3 | ext4)
(
echo "mkdir -p $TARGET_FS_ROOT$mountpoint"
echo "mount $mountopts $device $TARGET_FS_ROOT$mountpoint"
# try remount for xattr
# mount and then try remount for systems supporting xattr
# add a second mount for extended attr (selinux)
# the first mount will do perform the basic mount, the second mount (remount) will try for xattr
# if xattr are not support, the mount will fail, however, the first mount will still be in effect and not cause any errors
echo "mount $mountopts,remount,user_xattr $device $TARGET_FS_ROOT$mountpoint"
) >> "$LAYOUT_CODE"
;;
(xfs)
# remove logbsize=... mount option. It is a purely performance/memory usage optimization option,
# which can lead to mount failures, because it must be an integer multiple of the log stripe unit
# and the log stripe unit can be different in the recreated filesystem from the original filesystem
# (for example when using MKFS_XFS_OPTIONS, or in some exotic situations involving an old filesystem,
# see GitHub issue #2777 ).
# If logbsize is not an integer multiple of the log stripe unit, mount fails with the warning
# "XFS (...): logbuf size must be greater than or equal to log stripe size"
# in the kernel log
# (and a confusing error message
# "mount: ...: wrong fs type, bad option, bad superblock on ..., missing codepage or helper program, or other error."
# from the mount command), causing the layout restoration in the recovery process to fail.
# Wrong sunit/swidth can cause mount to fail as well, with this in the kernel log:
# "kernel: XFS (...): alignment check failed: sunit/swidth vs. agsize",
# so remove the sunit=.../swidth=... mount options as well.
mountopts="$( remove_mount_options_values "$mountopts" logbsize sunit swidth )"
(
echo "mkdir -p $TARGET_FS_ROOT$mountpoint"
echo "mount $mountopts $device $TARGET_FS_ROOT$mountpoint"
) >> "$LAYOUT_CODE"
;;
(*)
(
echo "mkdir -p $TARGET_FS_ROOT$mountpoint"
echo "mount $mountopts $device $TARGET_FS_ROOT$mountpoint"
) >> "$LAYOUT_CODE"
;;
esac
# Return successfully:
Log "End mount_fs( $@ )"
true
}