ssh core_collector fix

1. add core_collector filter support to ssh dump
2. scp can be specified in kdump.conf
3. error out if no '-F' with makedumpfile
4. add proper explanation and examples to kdump.conf[.5] and kexec-kdump-howto.txt.

v1->v2: add verify_core_collector function
v2->v3: optimize the code, remove local variable for default core_collector

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

dracut-kdump.sh

@@ -4,7 +4,8 @@
 
 set -x
 KDUMP_PATH="/var/crash"
-CORE_COLLECTOR="makedumpfile -c --message-level 1 -d 31"
+CORE_COLLECTOR=""
+DEFAULT_CORE_COLLECTOR="makedumpfile -c --message-level 1 -d 31"
 DEFAULT_ACTION="dump_rootfs"
 DATEDIR=`date +%d.%m.%y-%T`
 DUMP_INSTRUCTION=""
@@ -118,9 +119,23 @@ dump_nfs()
 
 dump_ssh()
 {
-    ssh -q -i $1 -o BatchMode=yes -o StrictHostKeyChecking=yes $2 mkdir -p $KDUMP_PATH/$DATEDIR || return 1
-    scp -q -i $1 -o BatchMode=yes -o StrictHostKeyChecking=yes /proc/vmcore "$2:$KDUMP_PATH/$DATEDIR"  || return 1
-    return 0
+    local _opt="-i $1 -o BatchMode=yes -o StrictHostKeyChecking=yes"
+    local _dir="$KDUMP_PATH/$DATEDIR"
+
+    ssh -q $_opt $2 mkdir -p $_dir || return 1
+
+    if [ "${CORE_COLLECTOR%% *}" = "scp" ]; then
+        scp -q $_opt /proc/vmcore "$2:$_dir/vmcore-incomplete" || return 1
+        ssh $_opt $2 "mv $_dir/vmcore-incomplete $_dir/vmcore" || return 1
+    else
+        $CORE_COLLECTOR /proc/vmcore | ssh $_opt $2 "dd bs=512 of=$_dir/vmcore-incomplete" || return 1
+        ssh $_opt $2 "mv $_dir/vmcore-incomplete $_dir/vmcore.flat" || return 1
+    fi
+}
+
+is_ssh_dump_target()
+{
+    grep -q "^net.*@" $conf_file
 }
 
 read_kdump_conf()
@@ -188,6 +203,11 @@ read_kdump_conf()
 
 read_kdump_conf
 
+if [ -z "$CORE_COLLECTOR" ];then
+    CORE_COLLECTOR=$DEFAULT_CORE_COLLECTOR
+    is_ssh_dump_target && CORE_COLLECTOR="$CORE_COLLECTOR -F"
+fi
+
 if [ -z "$DUMP_INSTRUCTION" ]; then
     add_dump_code "dump_rootfs"
 fi

kdump.conf

@@ -44,7 +44,7 @@
 #			  options are not needed here, as the initrd will
 #			  automatically be populated with a config file
 #			  appropriate for the running kernel.
-#			  Default core_collector for raw dump is:
+#			  Default core_collector for raw/ssh dump is:
 #			  "makedumpfile -F -c --message-level 1 -d 31".
 #			  Default core_collector for other targets is:
 #			  "makedumpfile -c --message-level 1 -d 31".
@@ -91,6 +91,7 @@
 #sshkey /root/.ssh/kdump_id_rsa
 path /var/crash
 #core_collector makedumpfile -c --message-level 1 -d 31
+#core_collector scp
 #extra_bins /usr/bin/lftp
 #extra_modules gfs2
 #default shell

kdump.conf.5

@@ -72,7 +72,7 @@ will automatically be populated with a config file appropriate
 for the running kernel.
 .PP
 Note 1: About default core collector:
-Default core_collector for raw dump is:
+Default core_collector for raw/ssh dump is:
 "makedumpfile -F -c --message-level 1 -d 31".
 Default core_collector for other targets is:
 "makedumpfile -c --message-level 1 -d 31".
@@ -141,10 +141,10 @@ Above will effectively be translated to:
 
 makedumpfile -c --message-level 1 -d 31 /proc/vmcore <dest-path>/vmcore
 .PP
-For dump targets like raw, in general, core collector should expect
+For dump targets like raw and ssh, in general, core collector should expect
 one argument (source file) and should output the processed core on standard
-output. This standard output will be saved to destination using appropriate
-commands.
+output (There is one exception of "scp", discussed later). This standard
+output will be saved to destination using appropriate commands.
 
 raw dumps examples:
 .TP
@@ -161,6 +161,34 @@ core_collector "makedumpfile -F -c --message-level 1 -d 31"
 Above will effectively be translated to.
 
 makedumpfile -F -c --message-level 1 -d 31 | dd of=<target-device>
+.PP
+ssh dumps examples
+.TP
+ex5.
+core_collector "cat"
+
+Above will effectively be translated to.
+
+cat /proc/vmcore | ssh <options> <remote-location> "dd of=path/vmcore"
+.TP
+ex6.
+core_collector "makedumpfile -F -c --message-level 1 -d 31"
+
+Above will effectively be translated to.
+
+makedumpfile -F -c --message-level 1 -d 31 | ssh <options> <remote-location> "dd of=path/vmcore"
+
+There is one exception to standard output rule for ssh dumps. And that is
+scp. As scp can handle ssh destinations for file transfers, one can
+specify "scp" as core collector for ssh targets (no output on stdout).
+.TP
+ex7.
+core_collector "scp"
+
+Above will effectively be translated to.
+
+scp /proc/vmcore <user@host>:path/vmcore
+
 .PP
 examples for other options please see
 .I /etc/kdump.conf

kexec-kdump-howto.txt

@@ -467,10 +467,10 @@ Above will effectively be translated to:
 makedumpfile -c --message-level 1 -d 31 /proc/vmcore <dest-path>/vmcore
 
 
-For dump targets like raw, in general, core collector should expect
+For dump targets like raw and ssh, in general, core collector should expect
 one argument (source file) and should output the processed core on standard
-output. This standard output will be saved to destination using appropriate
-commands.
+output (There is one exception of "scp", discussed later). This standard
+output will be saved to destination using appropriate commands.
 
 raw dumps core_collector examples:
 ---------
@@ -490,6 +490,36 @@ Above will effectively be translated to.
 
 makedumpfile -F -c --message-level 1 -d 31 | dd of=<target-device>
 
+ssh dumps core_collector examples:
+---------
+ex5.
+---
+core_collector "cat"
+
+Above will effectively be translated to.
+
+cat /proc/vmcore | ssh <options> <remote-location> "dd of=path/vmcore"
+
+ex6.
+---
+core_collector "makedumpfile -F -c --message-level 1 -d 31"
+
+Above will effectively be translated to.
+
+makedumpfile -F -c --message-level 1 -d 31 | ssh <options> <remote-location> "dd of=path/vmcore"
+
+There is one exception to standard output rule for ssh dumps. And that is
+scp. As scp can handle ssh destinations for file transfers, one can
+specify "scp" as core collector for ssh targets (no output on stdout).
+
+ex7.
+----
+core_collector "scp"
+
+Above will effectively be translated to.
+
+scp /proc/vmcore <user@host>:path/vmcore
+
 About default core collector
 ----------------------------
 Default core_collector for ssh/raw dump is:

mkdumprd

@@ -91,6 +91,24 @@ check_remote() {
     return
 }
 
+is_ssh_dump_target()
+{
+    grep -q "^net.*@" $conf_file
+}
+
+# $1: core_collector config value
+verify_core_collector() {
+    if grep -q "^raw" $conf_file && [ "${1%% *}" != "makedumpfile" ]; then
+        echo "Warning: specifying a non-makedumpfile core collector, you will have to recover the vmcore manually."
+    fi
+    if is_ssh_dump_target && [ "${1%% *}" = "makedumpfile" ]; then
+        ! strstr "$1" "-F" && {
+            echo "The specified dump target needs makedumpfile \"-F\" option."
+            exit 1
+        }
+    fi
+}
+
 add_mount() {
     local _dev=$(to_dev_name "$1")
     local _mnt=$(to_mount "$1")
@@ -150,9 +168,7 @@ do
         fi
         ;;
     core_collector)
-        if grep -q "^raw" $conf_file && [ "${config_val%% *}" != "makedumpfile" ]; then
-            echo "Warning: specifying a non-makedumpfile core collector, you will have to recover the vmcore manually."
-        fi
+        verify_core_collector "$config_val"
         add_dracut_arg "-I" "${config_val%% *}"
         ;;
     extra_bins)