From bde4b7af3b1517b78bb03f92f9fd7183aa532712 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Tue, 10 Mar 2020 23:52:33 +0800
Subject: [PATCH] No longer treat atomic/silverblue specially

This commit remove almost all special workaround for atomic, and treat
all bind mounts in any environment equally.

Use a helper get_bind_mount_directory_from_path to get the bind mount
source path of given path.

is_atomic function now only used to determine the right /boot path
for atomic/silverblue environment.

And remove get_mntpoint_from_path(), it's the only function that never
ignore bind mount, and it have no caller after this clean up.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Lianbo Jiang <lijiang@redhat.com>
---
 dracut-module-setup.sh | 36 +++++-----------------
 kdump-lib.sh           | 69 +++++++++++++-----------------------------
 mkdumprd               | 17 +++--------
 3 files changed, 32 insertions(+), 90 deletions(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 2c8d714..0f6f1cb 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -428,19 +428,9 @@ default_dump_target_install_conf()
 
     is_user_configured_dump_target && return
 
-    _save_path=$(get_save_path)
-    _mntpoint=$(get_mntpoint_from_path $_save_path)
+    _save_path=$(get_bind_mount_source $(get_save_path))
     _target=$(get_target_from_path $_save_path)
-
-    if is_atomic && is_bind_mount $_mntpoint; then
-        _save_path=${_save_path##"$_mntpoint"}
-        # the real dump path in the 2nd kernel, if the mount point is bind mounted.
-        _save_path=$(get_bind_mount_directory $_mntpoint)/$_save_path
-        _mntpoint=$(get_mntpoint_from_target $_target)
-
-        # the absolute path in the 1st kernel
-        _save_path=$_mntpoint/$_save_path
-    fi
+    _mntpoint=$(get_mntpoint_from_target $_target)
 
     _fstype=$(get_fs_type_from_target $_target)
     if is_fs_type_nfs $_fstype; then
@@ -452,8 +442,6 @@ default_dump_target_install_conf()
 
     echo "$_fstype $_target" >> ${initdir}/tmp/$$-kdump.conf
 
-    # strip the duplicated "/"
-    _save_path=$(echo $_save_path | tr -s /)
     # don't touch the path under root mount
     if [ "$_mntpoint" != "/" ]; then
         _save_path=${_save_path##"$_mntpoint"}
@@ -466,21 +454,13 @@ default_dump_target_install_conf()
 
 adjust_bind_mount_path()
 {
-    local _target=$1
     local _save_path=$(get_save_path)
-    local _absolute_save_path=$(get_mntpoint_from_target $_target)/$_save_path
+    local _mntpoint=$(get_mntpoint_from_target $1)
+    local _absolute_save_path=$(get_bind_mount_source $_mntpoint$_save_path)
 
-    _absolute_save_path=$(echo "$_absolute_save_path" | tr -s /)
-    local _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
-
-    if is_bind_mount $_mntpoint; then
-        _save_path=${_absolute_save_path##"$_mntpoint"}
-        # the real dump path in the 2nd kernel, if the mount point is bind mounted.
-        _save_path=$(get_bind_mount_directory $_mntpoint)/$_save_path
-
-        #erase the old path line, then insert the parsed path
+    if [ $_absolute_save_path != $_save_path ]; then
         sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
-        echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
+        echo "path $_absolute_save_path" >> ${initdir}/tmp/$$-kdump.conf
     fi
 }
 
@@ -500,9 +480,7 @@ kdump_install_conf() {
         ext[234]|xfs|btrfs|minix)
             _pdev=$(kdump_get_persistent_dev $_val)
             sed -i -e "s#^$_opt[[:space:]]\+$_val#$_opt $_pdev#" ${initdir}/tmp/$$-kdump.conf
-            if is_atomic; then
-                adjust_bind_mount_path "$_val"
-            fi
+            adjust_bind_mount_path "$_val"
             ;;
         ssh|nfs)
             kdump_install_net "$_val"
diff --git a/kdump-lib.sh b/kdump-lib.sh
index 6d421d3..b079f27 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -204,44 +204,39 @@ get_kdump_targets()
     echo "$kdump_targets"
 }
 
-
+# Return the bind mount source path, return the path itself if it's not bind mounted
+# Eg. if /path/to/src is bind mounted to /mnt/bind, then:
+# /mnt/bind -> /path/to/src, /mnt/bind/dump -> /path/to/src/dump
+#
 # findmnt uses the option "-v, --nofsroot" to exclusive the [/dir]
 # in the SOURCE column for bind-mounts, then if $_mntpoint equals to
 # $_mntpoint_nofsroot, the mountpoint is not bind mounted directory.
-is_bind_mount()
-{
-    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
-    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
-
-    if [[ $_mntpoint = $_mntpoint_nofsroot ]]; then
-        return 1
-    else
-        return 0
-    fi
-}
-
+#
 # Below is just an example for mount info
 # /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
 # directory is bind mounted. The former part represents the device path, rest
 # part is the bind mounted directory which quotes by bracket "[]".
-get_bind_mount_directory()
+get_bind_mount_source()
 {
-    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
-    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
+    local _path=$1
+    # In case it's a sub path in a mount point, get the mount point first
+    local _mnt_top=$(df $_path | tail -1 | awk '{print $NF}')
+    local _mntpoint=$(findmnt $_mnt_top | tail -n 1 | awk '{print $2}')
+    local _mntpoint_nofsroot=$(findmnt -v $_mnt_top | tail -n 1 | awk '{print $2}')
+
+    if [[ "$_mntpoint" = $_mntpoint_nofsroot ]]; then
+        echo $_path && return
+    fi
 
     _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
-
     _mntpoint=${_mntpoint#[}
     _mntpoint=${_mntpoint%]}
+    _path=${_path#$_mnt_top}
 
-    echo $_mntpoint
-}
-
-get_mntpoint_from_path()
-{
-    df $1 | tail -1 | awk '{print $NF}'
+    echo $_mntpoint$_path
 }
 
+# Return the real underlaying device of a path, ignore bind mounts
 get_target_from_path()
 {
     local _target
@@ -256,33 +251,11 @@ get_fs_type_from_target()
     findmnt -k -f -n -r -o FSTYPE $1
 }
 
-# input: device path
-# output: the general mount point
-# find the general mount point, not the bind mounted point in atomic
-# As general system, Use the previous code
-#
-# ERROR and EXIT:
-# the device can be umounted the general mount point, if one of the mount point is bind mounted
-# For example:
-# mount /dev/sda /mnt/
-# mount -o bind /mnt/var /var
-# umount /mnt
+# Find the general mount point of a dump target, not the bind mount point
 get_mntpoint_from_target()
 {
-    if is_atomic; then
-        for _mnt in $(findmnt -k -n -r -o TARGET $1)
-        do
-            if ! is_bind_mount $_mnt; then
-                echo $_mnt
-                return
-            fi
-        done
-
-        echo "Mount $1 firstly, without the bind mode" >&2
-        exit 1
-    else
-        echo $(findmnt -k -f -n -r -o TARGET $1)
-    fi
+    # Expcilitly specify --source to findmnt could ensure non-bind mount is returned
+    findmnt -k -f -n -r -o TARGET --source $1
 }
 
 # get_option_value <option_name>
diff --git a/mkdumprd b/mkdumprd
index 4fcce1c..35f5eed 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -240,20 +240,11 @@ handle_default_dump_target()
 
     check_save_path_fs $SAVE_PATH
 
-    _mntpoint=$(get_mntpoint_from_path $SAVE_PATH)
-    _target=$(get_target_from_path $SAVE_PATH)
+    _save_path=$(get_bind_mount_source $SAVE_PATH)
+    _target=$(get_target_from_path $_save_path)
+    _mntpoint=$(get_mntpoint_from_target $_target)
 
-    if is_atomic && is_bind_mount $_mntpoint; then
-        SAVE_PATH=${SAVE_PATH##"$_mntpoint"}
-        # the real dump path in the 2nd kernel, if the mount point is bind mounted.
-        SAVE_PATH=$(get_bind_mount_directory $_mntpoint)/$SAVE_PATH
-        _mntpoint=$(get_mntpoint_from_target $_target)
-
-        # the absolute path in the 1st kernel
-        SAVE_PATH=$_mntpoint/$SAVE_PATH
-    fi
-
-    SAVE_PATH=${SAVE_PATH##"$_mntpoint"}
+    SAVE_PATH=${_save_path##"$_mntpoint"}
     add_mount "$_target"
     check_size fs $_target
 }