[kexec-tools] mkdumprd: return error if no write permission on save path of server for ssh

[Baoquan He]

commit 83ef43e52237f1bb17fd4c73b9d0d63e8665f6c9
Author: Baoquan He <bhe at redhat.com>
Date:   Thu Jun 13 16:49:38 2013 +0800

    mkdumprd: return error if no write permission on save path of server for ssh
    
    When ssh dump, if user doesn't have write permission on save path
    of server, the crash kernel can be loaded successfully, but finally
    kdump will fail because write is not allowed.
    
    Let's check it in the service start phase, if no write permission
    print error message and exit.
    
    For differentiation, change the name of old function mkdir_save_path
    to mkdir_save_path_fs.
    
    Signed-off-by: Baoquan He <bhe at redhat.com>
    Acked-by: Vivek Goyal <vgoyal at redhat.com>

 mkdumprd |   30 ++++++++++++++++++++++++++++--
 1 files changed, 28 insertions(+), 2 deletions(-)
---
diff --git a/mkdumprd b/mkdumprd
index 83d34d6..b408b37 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -139,10 +139,35 @@ get_ssh_size() {
     echo -n $_size
 }
 
+#mkdir if save path does not exist on ssh dump target
+#$1=ssh dump target
+#caller should ensure write permission on $DUMP_TARGET:$SAVE_PATH
+mkdir_save_path_ssh()
+{
+    local _opt _dir
+    _opt="-i $SSH_KEY_LOCATION -o BatchMode=yes -o StrictHostKeyChecking=yes"
+    ssh -q $_opt $1 mkdir -p $SAVE_PATH 2>&1 > /dev/null
+    _ret=$?
+    if [ $_ret -ne 0 ]; then
+        perror_exit "mkdir failed on $DUMP_TARGET:$SAVE_PATH"
+    fi
+
+    #check whether user has write permission on $SAVE_PATH/$DUMP_TARGET
+    _dir=$(ssh -qn $_opt $1 mktemp -dqp $SAVE_PATH 2>/dev/null)
+    _ret=$?
+    if [ $_ret -ne 0 ]; then
+        perror_exit "Could not create temporary directory on $DUMP_TARGET:$SAVE_PATH. Make sure user has write permission on destination"
+    fi
+    ssh -q $_opt $1 rmdir $_dir
+
+    return 0
+}
+
+
 #mkdir if save path does not exist on dump target filesystem
 #$1=dump target
 #caller should ensure $1 is mounted
-mkdir_save_path() {
+mkdir_save_path_fs() {
     local _mnt=$(to_mount_point $1)
     local _remount="no"
     local _ret
@@ -496,7 +521,7 @@ do
             add_dracut_module "nfs"
         fi
         add_mount "$config_val"
-        mkdir_save_path $config_val
+        mkdir_save_path_fs $config_val
         check_size fs $config_val
         ;;
     raw)
@@ -511,6 +536,7 @@ do
         if strstr "$config_val" "@";
         then
             check_size ssh $config_val
+            mkdir_save_path_ssh $config_val
             add_dracut_module "ssh-client"
 		add_dracut_sshkey "$SSH_KEY_LOCATION"
         else