[kexec-tools] pass mount info to dracut when default target is a separate disk

[WANG Chao]

commit f8d7090b59dfa9b6af28256b26eb7252ed895ba7
Author: Baoquan He <bhe at redhat.com>
Date:   Fri Apr 11 20:27:01 2014 +0800

    pass mount info to dracut when default target is a separate disk
    
    When user does not specify dump target explicitly, it's better to
    dump to the "path" specified. That means after dump user enter into
    1st kernel, can find vmcore in the "path". If that path is in root
    fs, vmcore is stored in root fs. If separate disk is mounted on
    any tier of "path", we just dump vmcore into the left path on the
    left separate disk.
    
    E.g in kdump.conf
    path /mnt/nfs
    
    in mount info,
    /dev/vdb on /mnt type ext4 (rw,relatime,seclabel,data=ordered)
    
    Then vmcore will be saved in /nfs of /dev/vdb.
    
    In this patch, pass mount info to dracut in this case if separate
    disk is mounted on any tier of "path".
    
    Meanwhile introduce a function in kdump-lib.sh to check if any
    target is specified.
    
    v4->v5:
        Per Vivek's comment, add a helper function is_fs_dump_target.
        Then is_user_configured_dump_target is rewrite with these helper
        functions.
    
    v5->v7:
        No v6 for this patch. Just use newly introduced function
        is_fs_type_nfs in handle_default_dump_target.
    
    Signed-off-by: Baoquan He <bhe at redhat.com>
    Acked-by: Vivek Goyal <vgoyal at redhat.com>

 kdump-lib.sh |   24 ++++++++++--------------
 mkdumprd     |   31 ++++++++++++++++++-------------
 2 files changed, 28 insertions(+), 27 deletions(-)
---
diff --git a/kdump-lib.sh b/kdump-lib.sh
index c629af8..a20c6e8 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -29,6 +29,16 @@ is_fs_type_nfs()
     return 1
 }
 
+is_fs_dump_target()
+{
+    egrep -q "^ext[234]|^xfs|^btrfs|^minix" /etc/kdump.conf
+}
+
+is_user_configured_dump_target()
+{
+    return $(is_ssh_dump_target || is_nfs_dump_target || is_raw_dump_target || is_fs_dump_target)
+}
+
 strip_comments()
 {
     echo $@ | sed -e 's/\(.*\)#.*/\1/'
@@ -67,20 +77,6 @@ get_user_configured_dump_disk()
     return
 }
 
-is_user_configured_dump_target()
-{
-    local _target
-
-    if is_ssh_dump_target || is_nfs_dump_target; then
-        return 0
-    fi
-
-    _target=$(egrep "^ext[234]|^xfs|^btrfs|^minix|^raw" /etc/kdump.conf 2>/dev/null |awk '{print $2}')
-    [ -n "$_target" ] && return 0
-
-    return 1
-}
-
 get_root_fs_device()
 {
     local _target
diff --git a/mkdumprd b/mkdumprd
index adf9167..0376320 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -325,24 +325,29 @@ get_block_dump_target()
     [ -b "$_target" ] && echo $(to_dev_name $_target)
 }
 
-# If no dump disk is specified make sure /var/crash is not mounted on a
-# separate disk.
-check_block_dump_target()
+#handle the case user does not specify the dump target explicitly
+handle_default_dump_target()
 {
     local _target
     local _mntpoint
+    local _fstype
 
     is_user_configured_dump_target && return
 
-    _target=$(get_root_fs_device)
-    if [ -b "$_target" ]; then
-        mkdir -p $SAVE_PATH
-        _mntpoint=`df $SAVE_PATH | tail -1 |  awk '{print $NF}'`
-        if [ "$_mntpoint" != "/" ]; then
-            perror "No dump target specified. Default dump target is rootfs block device."
-            perror "But dump path $SAVE_PATH is not backed by rootfs block device. "
-            perror_exit "Either explicitly specify a dump target or specify a dump path backed by rootfs block device"
+    check_save_path_fs $SAVE_PATH
+
+    _mntpoint=$(get_mntpoint_from_path $SAVE_PATH)
+    _target=$(get_target_from_path $SAVE_PATH)
+    if [ "$_mntpoint" != "/" ]; then
+        SAVE_PATH=${SAVE_PATH##"$_mntpoint"}
+        _fstype=$(get_fs_type_from_target $_target)
+
+        if $(is_fs_type_nfs $_fstype); then
+            add_dracut_module "nfs"
         fi
+
+        add_mount "$_target"
+        check_size fs $_target
     fi
 }
 
@@ -469,8 +474,6 @@ check_crypt()
     return 1
 }
 
-check_block_dump_target
-
 if ! check_resettable; then
     exit 1
 fi
@@ -548,6 +551,8 @@ do
     esac
 done < $conf_file
 
+handle_default_dump_target
+
 if [ -n "$extra_modules" ]
 then
     add_dracut_arg "--add-drivers" "$extra_modules"