[RFC PATCH 6/8] mkdumprd: add a generic hook for the dump target

[Xunlei Pang]

We add a generic hook named kdump_target_hook() for the
dump target, this is useful for us to do some extra work
for different types of dump targets.

kdump_target_check() is exported as a generic helper that
can be used as some specific purpose.

We will use this mechanism in the following patch.

Signed-off-by: Xunlei Pang <xlpang(a)redhat.com&gt;
---
 kdump-lib.sh | 13 ++++++++++
 mkdumprd     | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 1 deletion(-)

diff --git a/kdump-lib.sh b/kdump-lib.sh
index 0f74b8e..aafa21e 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -418,3 +418,16 @@ is_fadump_capable()
 	fi
 	return 1
 }
+
+# $1: item
+# Did the item left a tag in the inventory?
+# return: 0 means surely left; 1 means surely not
+kdump_target_check()
+{
+    local item=$1 tag
+
+    tag=$(eval echo '${KDUMP_TARGET_TAG_'${item}'}')
+    [ -n "$tag" ] && return 0
+
+    return 1
+}
diff --git a/mkdumprd b/mkdumprd
index 892e59a..392eb7f 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -11,6 +11,9 @@
 . /lib/kdump/kdump-lib.sh
 export IN_KDUMP=1
 
+# See kdump_target_XXX()
+KDUMP_TARGET_CHECKLIST=""
+
 conf_file="/etc/kdump.conf"
 SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"
 SAVE_PATH=$(grep ^path $conf_file| cut -d' '  -f2)
@@ -250,6 +253,65 @@ add_mount() {
     add_dracut_mount "$_mnt"
 }
 
+# $1: ssh, nfs, or block dev name
+kdump_target_hook()
+{
+    local dev=$1
+
+    # Do not support fadump currently
+    if is_fadump_capable; then
+        return
+    fi
+
+    # Ignore non-block device currently
+    if ! [ -b "$dev" ]; then
+        return
+    fi
+
+    dev=$(get_persistent_dev $dev)
+    kdump_target_checklist "$KDUMP_TARGET_CHECKLIST" $dev
+}
+
+# $1: items to be checked
+# $2: persistent block dev name
+kdump_target_checklist()
+{
+    local items=$1 pdev=$2
+
+    for item in $items; do
+        kdump_target_handle $item $pdev
+    done
+}
+
+# $1: the item to be checked
+# $2: persistent block dev name
+#
+# You can add an item in KDUMP_TARGET_CHECKLIST, handle it here
+# and leave its tag(KDUMP_TARGET_TAG_$item) in the tag inventory
+# as needed.
+kdump_target_handle()
+{
+    local item=$1 pdev=$2
+    local tag
+
+    tag=KDUMP_TARGET_TAG_$item
+    # the item handling begins
+    case "$item" in
+    *)
+        echo "unhandled item in kdump target checklist"
+        return
+    esac
+
+    kdump_target_leave_tag $tag
+}
+
+# Leave the tag in the tag inventory.
+# $1: tag
+kdump_target_leave_tag()
+{
+    eval export $1=1
+}
+
 get_block_dump_target()
 {
     local _target
@@ -291,6 +353,8 @@ handle_default_dump_target()
     _fstype=$(get_fs_type_from_target $_target)
     add_mount "$_target"
     check_size fs $_target
+
+    kdump_target_hook $_target
 }
 
 get_default_action_target()
@@ -459,6 +523,12 @@ do
         add_mount "$config_val"
         check_save_path_fs $_absolute_save_path
         check_size fs $config_val
+
+        if [ $config_opt = "nfs" ]; then
+            kdump_target_hook "nfs"
+        else
+            kdump_target_hook $config_val
+        fi
         ;;
     raw)
         #checking raw disk writable
@@ -471,6 +541,7 @@ do
         fi
         add_dracut_arg "--device" "$_praw"
         check_size raw $config_val
+        kdump_target_hook $_praw
         ;;
     ssh)
         if strstr "$config_val" "@";
@@ -478,7 +549,8 @@ do
             check_size ssh $config_val
             mkdir_save_path_ssh $config_val
             add_dracut_module "ssh-client"
-		add_dracut_sshkey "$SSH_KEY_LOCATION"
+            add_dracut_sshkey "$SSH_KEY_LOCATION"
+            kdump_target_hook "ssh"
         else
             perror_exit "Bad ssh dump target $config_val"
         fi
@@ -488,6 +560,16 @@ do
         ;;
     dracut_args)
         add_dracut_arg $config_val
+
+        dracut_args_dev=$(get_dracut_args_target "$config_val")
+        if [ -n "$dracut_args_dev" ]; then
+            dracut_args_fstype=$(get_dracut_args_fstype "$config_val")
+            if is_fs_type_nfs $dracut_args_fstype ; then
+                kdump_target_hook "nfs"
+            else
+                kdump_target_hook $dracut_args_dev
+            fi
+        fi
         ;;
     *)
         if [ -n $(echo $config_opt | grep "^#.*$") ]
-- 
1.8.3.1