[PATCH 0/3 v2] Enhance kdump to support bind mounted feature in Atomic

[Minfei Huang]

These patchset bases on the patch:
Author: Minfei Huang <mhuang(a)redhat.com&gt;
Date:   Tue Mar 3 20:54:54 2015 +0800

    kdump-lib: Add new function to fix duplicated "/" in path

Enhance kdump to support bind mounted target in Atomic, since kdump
cann't parse the bind mounted path.

Following is the testcases which kdump can generate the core sucessfully.
  1) rootfs, default path / specified path
  2) rootfs with bind mounted path which is in the rootfs device
        # cat /etc/kdump | grep ^path
        path /var/crash
        # mount -o bind /var/crash /mnt/crash
  4) rootfs with bind mounted path which is not in the rootfs device
        # cat /etc/kdump | grep ^path
        path /var/crash
        # mount /dev/vdb /mnt
        # mount -o bind /var/crash /mnt/crash
  5) no-rootfs
  6) no-rootfs with bind mounted path which is in the same device
  7) no-rootfs with bind mounted path which is not in the same device
  8) nfs
  9) nfs with bind mounted path which is under the nfs mount point path
        # cat /etc/kdump | grep ^nfs
        nfs 192.168.122.134:/opt/crash
        # cat /etc/kdump | grep ^path
        path /var/crash
        # mount.nfs 192.168.122.134:/opt/crash /mnt/nfs
        # mount -o bind /mnt/nfs/var/crash /mnt/nfs/dump
 10) nfs with bind mounted path which is not under the nfs mount point path
        # cat /etc/kdump | grep ^nfs
        nfs 192.168.122.134:/opt/crash
        # cat /etc/kdump | grep ^path
        path /var/crash
        # mount.nfs 192.168.122.134:/opt/crash /mnt/nfs
        # mount -o bind /mnt/nfs/var/crash /mnt/dump
 11) nfs which don't specify the nfs option in the /etc/kdump, with bind mounted path
which is under the nfs mount point path 
        # cat /etc/kdump | grep ^nfs
        # mount.nfs 192.168.122.134:/opt/crash /mnt/nfs
        # cat /etc/kdump | grep ^path
        path /mnt/nfs/var/crash
        # mount -o bind /mnt/nfs/var/crash /mnt/nfs/dump
 12) nfs which don't specify the nfs option in the /etc/kdump, with bind mounted path
which is not under the nfs mount point path 
        # cat /etc/kdump | grep ^nfs
        # mount.nfs 192.168.122.134:/opt/crash /mnt/nfs
        # cat /etc/kdump | grep ^path
        path /mnt/nfs/var/crash
        # mount -o bind /mnt/nfs/var/crash /mnt/dump
 13) ext4
 14) ext4 with bind mounted path which is under the ext4 mount point path
 15) ext4 with bind mounted path which is not under the ext4 mount point path
 16) btrfs
 17) btrfs with subvolume which mounts under mount point path
 18) btrfs with subvolume which does not mount under mount point path

Minfei Huang (3):
  kdump-lib: Add the new function to enhance bind mounted judgement
  kdump-lib: Get the mount point correctly, if the device has several
    mount point
  dracut-module-setup: Enhance kdump to support the bind mounted feature
    in Atomic

===

v1:
- add the judgment to make it work only in Atomic

===

 dracut-module-setup.sh | 39 ++++++++++++++++++++++++++++++++++-----
 kdump-lib.sh           | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 mkdumprd               | 32 +++++++++++++++++++++++++-------
 3 files changed, 106 insertions(+), 13 deletions(-)

-- 
1.9.3

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Minfei Huang]

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.

the value of $_mntpoint may be
/dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
directory is bind mounted. The former part represents the device path, the
rest part is the bind mounted directory which quotes by bracket "[]".

Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
---
 kdump-lib.sh | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/kdump-lib.sh b/kdump-lib.sh
index ab01d74..2ad528e 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -86,6 +86,38 @@ get_root_fs_device()
     return
 }
 
+# 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
+}
+
+# the value of $_mntpoint will be
+# /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
+# directory is bind mounted. The former part represents the device path, rest
+# part is the bind mounted directory which quotes by bracket "[]".
+get_bind_mount_directory()
+{
+    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
+    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
+
+    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
+
+    _mntpoint=${_mntpoint#[}
+    _mntpoint=${_mntpoint%]}
+
+    echo $_mntpoint
+}
+
 get_mntpoint_from_path() 
 {
     echo $(df $1 | tail -1 |  awk '{print $NF}')
-- 
1.9.3

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Baoquan He]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  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.
>  
>  the value of $_mntpoint may be
>  /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  directory is bind mounted. The former part represents the device path, the
>  rest part is the bind mounted directory which quotes by bracket "[]".
>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt; 
It looks good to me. At least up to now no other better way to judge and
retrieve bind mount info.

Acked-by: Baoquan He <bhe(a)redhat.com&gt;

>  ---
>   kdump-lib.sh | 32 ++++++++++++++++++++++++++++++++
>   1 file changed, 32 insertions(+)
>  
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index ab01d74..2ad528e 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -86,6 +86,38 @@ get_root_fs_device()
>       return
>   }
>   
>  +# 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
>  +}
>  +
>  +# the value of $_mntpoint will be
>  +# /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  +# directory is bind mounted. The former part represents the device path, rest
>  +# part is the bind mounted directory which quotes by bracket "[]".
>  +get_bind_mount_directory()
>  +{
>  +    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
>  +    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
>  +
>  +    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
>  +
>  +    _mntpoint=${_mntpoint#[}
>  +    _mntpoint=${_mntpoint%]}
>  +
>  +    echo $_mntpoint
>  +}
>  +
>   get_mntpoint_from_path() 
>   {
>       echo $(df $1 | tail -1 |  awk '{print $NF}')
>  -- 
>  1.9.3
>

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Baoquan He]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  +# the value of $_mntpoint will be
>  +# /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 "[]". 
Hold on. I remember I suggested use sed command, you said it can't
handle this case, namely the name of file or dir contains a bracket:

/dev/mapper/atomicos-[root]

Does below function can handle it? What if below case?

/dev/mapper/atomicos-root[/ostree/deploy/[rhel-atomic-host]/var]


>  +get_bind_mount_directory()
>  +{
>  +    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
>  +    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
>  +
>  +    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
>  +
>  +    _mntpoint=${_mntpoint#[}
>  +    _mntpoint=${_mntpoint%]}
>  +
>  +    echo $_mntpoint
>  +}
>  +
>   get_mntpoint_from_path() 
>   {
>       echo $(df $1 | tail -1 |  awk '{print $NF}')
>  -- 
>  1.9.3
>

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Minfei Huang]

On 04/08/15 at 01:56pm, Baoquan He wrote:
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > +# the value of $_mntpoint will be
>  > +# /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 "[]".
>  
>  Hold on. I remember I suggested use sed command, you said it can't
>  handle this case, namely the name of file or dir contains a bracket:
>  
>  /dev/mapper/atomicos-[root]
>  
>  Does below function can handle it? What if below case?
>  
>  /dev/mapper/atomicos-root[/ostree/deploy/[rhel-atomic-host]/var]
>  
>   
Hi, Bao.

The function get_bind_mount_directory works well, while I use the above
testcase.

Thanks
Minfei

>  > +get_bind_mount_directory()
>  > +{
>  > +    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
>  > +    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print
> $2}')
>  > +
>  > +    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
>  > +
>  > +    _mntpoint=${_mntpoint#[}
>  > +    _mntpoint=${_mntpoint%]}
>  > +
>  > +    echo $_mntpoint
>  > +}
>  > +
>  >  get_mntpoint_from_path() 
>  >  {
>  >      echo $(df $1 | tail -1 |  awk '{print $NF}')
>  > -- 
>  > 1.9.3
>  >

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Baoquan He]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  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.
>  
>  the value of $_mntpoint may be
>  /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  directory is bind mounted. The former part represents the device path, the
>  rest part is the bind mounted directory which quotes by bracket "[]".
>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  ---
>   kdump-lib.sh | 32 ++++++++++++++++++++++++++++++++
>   1 file changed, 32 insertions(+)
>  
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index ab01d74..2ad528e 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -86,6 +86,38 @@ get_root_fs_device()
>       return
>   }
>   
>  +# findmnt uses the option "-v, --nofsroot" to exclusive the [/dir] 
     
                                           This is an adjective
word, please use exclude in v3.

>  +# 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
>  +}
>  +
>  +# the value of $_mntpoint will be
>  +# /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  +# directory is bind mounted. The former part represents the device path, rest
>  +# part is the bind mounted directory which quotes by bracket "[]".
>  +get_bind_mount_directory()
>  +{
>  +    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
>  +    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print $2}')
>  +
>  +    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
>  +
>  +    _mntpoint=${_mntpoint#[}
>  +    _mntpoint=${_mntpoint%]}
>  +
>  +    echo $_mntpoint
>  +}
>  +
>   get_mntpoint_from_path() 
>   {
>       echo $(df $1 | tail -1 |  awk '{print $NF}')
>  -- 
>  1.9.3
>

[PATCH 1/3 v2] kdump-lib: Add the new function to enhance bind mounted judgement

[Minfei Huang]

On 04/08/15 at 01:56pm, Baoquan He wrote:
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > 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.
>  > 
>  > the value of $_mntpoint may be
>  > /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  > directory is bind mounted. The former part represents the device path, the
>  > rest part is the bind mounted directory which quotes by bracket "[]".
>  > 
>  > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > ---
>  >  kdump-lib.sh | 32 ++++++++++++++++++++++++++++++++
>  >  1 file changed, 32 insertions(+)
>  > 
>  > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > index ab01d74..2ad528e 100755
>  > --- a/kdump-lib.sh
>  > +++ b/kdump-lib.sh
>  > @@ -86,6 +86,38 @@ get_root_fs_device()
>  >      return
>  >  }
>  >  
>  > +# findmnt uses the option "-v, --nofsroot" to exclusive the [/dir]
>                                                   This is an adjective
>  word, please use exclude in v3.
>   
Hi, Bao.

Thank you for your correction.

Thanks
Minfei

>  > +# 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
>  > +}
>  > +
>  > +# the value of $_mntpoint will be
>  > +# /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the
>  > +# directory is bind mounted. The former part represents the device path, rest
>  > +# part is the bind mounted directory which quotes by bracket "[]".
>  > +get_bind_mount_directory()
>  > +{
>  > +    local _mntpoint=$(findmnt $1 | tail -n 1 | awk '{print $2}')
>  > +    local _mntpoint_nofsroot=$(findmnt -v $1 | tail -n 1 | awk '{print
> $2}')
>  > +
>  > +    _mntpoint=${_mntpoint#*$_mntpoint_nofsroot}
>  > +
>  > +    _mntpoint=${_mntpoint#[}
>  > +    _mntpoint=${_mntpoint%]}
>  > +
>  > +    echo $_mntpoint
>  > +}
>  > +
>  >  get_mntpoint_from_path() 
>  >  {
>  >      echo $(df $1 | tail -1 |  awk '{print $NF}')
>  > -- 
>  > 1.9.3
>  >

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

The filesystem support the device to be mounted different mount points.
The root path in the device may be different, if the mount point is
mounted by bind mode. In order to dump core correctly, we should find
the root path in the device.

Following is the case that device is mounted by bind mode.

TARGET    SOURCE   FSTYPE OPTIONS
/mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
TARGET        SOURCE         FSTYPE OPTIONS
/mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache

We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
the other word, the /mnt/bind-dir points to the /var directory in the
/dev/vda.
The /mnt/ext4 is the root path in the device.

Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
---
 kdump-lib.sh | 11 ++++++++++-
 mkdumprd     |  8 ++------
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/kdump-lib.sh b/kdump-lib.sh
index 2ad528e..75d7673 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -135,7 +135,16 @@ get_fs_type_from_target()
 
 get_mntpoint_from_target()
 {
-    echo $(findmnt -k -f -n -r -o TARGET $1)
+    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
 }
 
 # get_option_value <option_name>
diff --git a/mkdumprd b/mkdumprd
index a8f9cbb..7fdcebf 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -100,7 +100,7 @@ to_mount() {
     local _dev=$1 _source _target _fstype _options _mntopts _pdev
 
     _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
-    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
+    _target=$(get_mntpoint_from_target $_dev)
     # mount under /sysroot if dump to root disk or mount under
     #/kdumproot/$_target in other cases in 2nd kernel. systemd
     #will be in charge to umount it.
@@ -144,10 +144,6 @@ to_mount() {
     echo "$_pdev $_mntopts"
 }
 
-to_mount_point() {
-    echo $(findmnt -k -f -n -r -o TARGET $1)
-}
-
 is_readonly_mount() {
     local _mnt
     _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
@@ -201,7 +197,7 @@ mkdir_save_path_ssh()
 #Function: get_fs_size
 #$1=dump target
 get_fs_size() {
-    local _mnt=$(to_mount_point $1)
+    local _mnt=$(get_mntpoint_from_target $1)
     echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')
 }
 
-- 
1.9.3

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Baoquan He]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  The filesystem support the device to be mounted different mount
> points. 
                                                 ^ Please add a
"on"
here.
>  The root path in the device may be different, if the mount point is
>  mounted by bind mode. In order to dump core correctly, we should find 
          ^
change it to "in".            ^ change it to vmcore.
>  the root path in the device.
>  
>  Following is the case that device is mounted by bind mode.
>  
>  TARGET    SOURCE   FSTYPE OPTIONS
>  /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  TARGET        SOURCE         FSTYPE OPTIONS
>  /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  
>  We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  the other word, the /mnt/bind-dir points to the /var directory in the
>  /dev/vda.
>  The /mnt/ext4 is the root path in the device. 
What do you mean here? In the end who is the mount point you want to
get? Please describe it clearly. Make people who don't talk to you face
to face can understand it.

>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  ---
>   kdump-lib.sh | 11 ++++++++++-
>   mkdumprd     |  8 ++------
>   2 files changed, 12 insertions(+), 7 deletions(-)
>  
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index 2ad528e..75d7673 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -135,7 +135,16 @@ get_fs_type_from_target()
>   
>   get_mntpoint_from_target()
>   {
>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  +    for _mnt in $(findmnt -k -n -r -o TARGET $1)
>  +    do
>  +        if ! is_bind_mount $_mnt; then
>  +            echo $_mnt
>  +            return 
You make a change against non bind mount case. non bind mount don't get
a mntpoint any more. Is that OK? And I don't see you explain it in patch
log.

>  +        fi
>  +    done
>  +
>  +    echo "Mount $1 firstly, without the bind mode" >&2
>  +    exit 1
>   }
>   
>   # get_option_value <option_name>
>  diff --git a/mkdumprd b/mkdumprd
>  index a8f9cbb..7fdcebf 100644
>  --- a/mkdumprd
>  +++ b/mkdumprd
>  @@ -100,7 +100,7 @@ to_mount() {
>       local _dev=$1 _source _target _fstype _options _mntopts _pdev
>   
>       _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  +    _target=$(get_mntpoint_from_target $_dev)
>       # mount under /sysroot if dump to root disk or mount under
>       #/kdumproot/$_target in other cases in 2nd kernel. systemd
>       #will be in charge to umount it.
>  @@ -144,10 +144,6 @@ to_mount() {
>       echo "$_pdev $_mntopts"
>   }
>   
>  -to_mount_point() {
>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  -}
>  -
>   is_readonly_mount() {
>       local _mnt
>       _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>   #Function: get_fs_size
>   #$1=dump target
>   get_fs_size() {
>  -    local _mnt=$(to_mount_point $1)
>  +    local _mnt=$(get_mntpoint_from_target $1)
>       echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')
>   }
>   
>  -- 
>  1.9.3
>

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/08/15 at 02:03pm, Baoquan He wrote:
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > The filesystem support the device to be mounted different mount points.
>                                                   ^ Please add a "on"
>  here.
>  > The root path in the device may be different, if the mount point is
>  > mounted by bind mode. In order to dump core correctly, we should find
>            ^ change it to "in".            ^ change it to vmcore.
>  > the root path in the device.
>  > 
>  > Following is the case that device is mounted by bind mode.
>  > 
>  > TARGET    SOURCE   FSTYPE OPTIONS
>  > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > TARGET        SOURCE         FSTYPE OPTIONS
>  > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > 
>  > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > the other word, the /mnt/bind-dir points to the /var directory in the
>  > /dev/vda.
>  > The /mnt/ext4 is the root path in the device.
>  
>  What do you mean here? In the end who is the mount point you want to
>  get? Please describe it clearly. Make people who don't talk to you face
>  to face can understand it.
>   
Hi, bao.

Thank you for your review.

We can find that /mnt/bind-dir is a bind mounted directory which points
to the /dev/vda[/var], meanwhile, the device /dev/vda is mounted on
directory /mnt/ext4. So the bind mounted directory /mnt/bind-dir points
to the /mnt/ext4/var.

How about above comment?

Thanks
Minfei

>  > 
>  > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > ---
>  >  kdump-lib.sh | 11 ++++++++++-
>  >  mkdumprd     |  8 ++------
>  >  2 files changed, 12 insertions(+), 7 deletions(-)
>  > 
>  > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > index 2ad528e..75d7673 100755
>  > --- a/kdump-lib.sh
>  > +++ b/kdump-lib.sh
>  > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  >  
>  >  get_mntpoint_from_target()
>  >  {
>  > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > +    for _mnt in $(findmnt -k -n -r -o TARGET $1)
>  > +    do
>  > +        if ! is_bind_mount $_mnt; then
>  > +            echo $_mnt
>  > +            return
>  
>  You make a change against non bind mount case. non bind mount don't get
>  a mntpoint any more. Is that OK? And I don't see you explain it in patch
>  log.
>   
Yes, the function get_mntpoint_from_target may fail, if all of the mount
points are in bind mode. If so, kdump will raise the error message, and
kill itself.

Will add the explanation.

Thanks
Minfei

>  > +        fi
>  > +    done
>  > +
>  > +    echo "Mount $1 firstly, without the bind mode" >&2
>  > +    exit 1
>  >  }
>  >  
>  >  # get_option_value <option_name>
>  > diff --git a/mkdumprd b/mkdumprd
>  > index a8f9cbb..7fdcebf 100644
>  > --- a/mkdumprd
>  > +++ b/mkdumprd
>  > @@ -100,7 +100,7 @@ to_mount() {
>  >      local _dev=$1 _source _target _fstype _options _mntopts _pdev
>  >  
>  >      _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  > -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  > +    _target=$(get_mntpoint_from_target $_dev)
>  >      # mount under /sysroot if dump to root disk or mount under
>  >      #/kdumproot/$_target in other cases in 2nd kernel. systemd
>  >      #will be in charge to umount it.
>  > @@ -144,10 +144,6 @@ to_mount() {
>  >      echo "$_pdev $_mntopts"
>  >  }
>  >  
>  > -to_mount_point() {
>  > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > -}
>  > -
>  >  is_readonly_mount() {
>  >      local _mnt
>  >      _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  > @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>  >  #Function: get_fs_size
>  >  #$1=dump target
>  >  get_fs_size() {
>  > -    local _mnt=$(to_mount_point $1)
>  > +    local _mnt=$(get_mntpoint_from_target $1)
>  >      echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print
> $4}')
>  >  }
>  >  
>  > -- 
>  > 1.9.3
>  >

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Baoquan He]

On 04/08/15 at 02:52pm, Minfei Huang wrote:
>  On 04/08/15 at 02:03pm, Baoquan He wrote:
>  > On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > > The filesystem support the device to be mounted different mount points.
>  >                                                  ^ Please add a "on"
>  > here.
>  > > The root path in the device may be different, if the mount point is
>  > > mounted by bind mode. In order to dump core correctly, we should find
>  >           ^ change it to "in".            ^ change it to vmcore.
>  > > the root path in the device.
>  > > 
>  > > Following is the case that device is mounted by bind mode.
>  > > 
>  > > TARGET    SOURCE   FSTYPE OPTIONS
>  > > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > > TARGET        SOURCE         FSTYPE OPTIONS
>  > > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > > 
>  > > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > > the other word, the /mnt/bind-dir points to the /var directory in the
>  > > /dev/vda.
>  > > The /mnt/ext4 is the root path in the device.
>  > 
>  > What do you mean here? In the end who is the mount point you want to
>  > get? Please describe it clearly. Make people who don't talk to you face
>  > to face can understand it.
>  > 
>  
>  Hi, bao.
>  
>  Thank you for your review.
>  
>  We can find that /mnt/bind-dir is a bind mounted directory which points
>  to the /dev/vda[/var], meanwhile, the device /dev/vda is mounted on
>  directory /mnt/ext4. So the bind mounted directory /mnt/bind-dir points
>  to the /mnt/ext4/var. 
Then what's the mount point you get? You tell a series of analysis,
what's the result?

Could you please assume a reviewer who didn't follow this issue want to
help review this patchset and get into it quickly? The reason for this
is we can recall these later by checking the commit log. I often forget
the details several months later.

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/08/15 at 04:03pm, Baoquan He wrote:
>  On 04/08/15 at 02:52pm, Minfei Huang wrote:
>  > On 04/08/15 at 02:03pm, Baoquan He wrote:
>  > > On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > > > The filesystem support the device to be mounted different mount points.
>  > >                                                  ^ Please add a "on"
>  > > here.
>  > > > The root path in the device may be different, if the mount point is
>  > > > mounted by bind mode. In order to dump core correctly, we should find
>  > >           ^ change it to "in".            ^ change it to vmcore.
>  > > > the root path in the device.
>  > > > 
>  > > > Following is the case that device is mounted by bind mode.
>  > > > 
>  > > > TARGET    SOURCE   FSTYPE OPTIONS
>  > > > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > > > TARGET        SOURCE         FSTYPE OPTIONS
>  > > > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > > > 
>  > > > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > > > the other word, the /mnt/bind-dir points to the /var directory in the
>  > > > /dev/vda.
>  > > > The /mnt/ext4 is the root path in the device.
>  > > 
>  > > What do you mean here? In the end who is the mount point you want to
>  > > get? Please describe it clearly. Make people who don't talk to you face
>  > > to face can understand it.
>  > > 
>  > 
>  > Hi, bao.
>  > 
>  > Thank you for your review.
>  > 
>  > We can find that /mnt/bind-dir is a bind mounted directory which points
>  > to the /dev/vda[/var], meanwhile, the device /dev/vda is mounted on
>  > directory /mnt/ext4. So the bind mounted directory /mnt/bind-dir points
>  > to the /mnt/ext4/var.
>  
>  Then what's the mount point you get? You tell a series of analysis,
>  what's the result?
>  
>  Could you please assume a reviewer who didn't follow this issue want to
>  help review this patchset and get into it quickly? The reason for this
>  is we can recall these later by checking the commit log. I often forget
>  the details several months later.
>   
Hi, bao.

I just show the view what bind mounted is. Where the real location is, if
the path is bind mounted.

Thanks
Minfei

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Baoquan He]

On 04/08/15 at 04:23pm, Minfei Huang wrote:
>  On 04/08/15 at 04:03pm, Baoquan He wrote: 
>  > > We can find that /mnt/bind-dir is a bind mounted directory
> which points
>  > > to the /dev/vda[/var], meanwhile, the device /dev/vda is mounted on
>  > > directory /mnt/ext4. So the bind mounted directory /mnt/bind-dir points
>  > > to the /mnt/ext4/var.
>  > 
>  > Then what's the mount point you get? You tell a series of analysis,
>  > what's the result?
>  > 
>  > Could you please assume a reviewer who didn't follow this issue want to
>  > help review this patchset and get into it quickly? The reason for this
>  > is we can recall these later by checking the commit log. I often forget
>  > the details several months later.
>  > 
>  
>  Hi, bao.
>  
>  I just show the view what bind mounted is. Where the real location is, if
>  the path is bind mounted. 
OK. I think in patch log you should present:

1) what's wrong when bind mount in current code, you can give a example
command.

2)The reason is the mount point is not correct and that cause storing in
wrong place in 2nd kernel.

3) how do you fix it with code in this patch. Namely how to get the
mount point correctly.

With the help of command example it should be easy to explain
what/why/how. So if you just show the view what bind mounted is, where
is the real location is if bind mount, I still need try it by myself to
get what's the correct mount point, but not get it directly from you
patch log.

Thanks
Baoquan

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/08/15 at 04:28pm, Baoquan He wrote:
>  On 04/08/15 at 04:23pm, Minfei Huang wrote:
>  > On 04/08/15 at 04:03pm, Baoquan He wrote:
>  
>  > > > We can find that /mnt/bind-dir is a bind mounted directory which points
>  > > > to the /dev/vda[/var], meanwhile, the device /dev/vda is mounted on
>  > > > directory /mnt/ext4. So the bind mounted directory /mnt/bind-dir points
>  > > > to the /mnt/ext4/var.
>  > > 
>  > > Then what's the mount point you get? You tell a series of analysis,
>  > > what's the result?
>  > > 
>  > > Could you please assume a reviewer who didn't follow this issue want to
>  > > help review this patchset and get into it quickly? The reason for this
>  > > is we can recall these later by checking the commit log. I often forget
>  > > the details several months later.
>  > > 
>  > 
>  > Hi, bao.
>  > 
>  > I just show the view what bind mounted is. Where the real location is, if
>  > the path is bind mounted.
>  
>  OK. I think in patch log you should present:
>  
>  1) what's wrong when bind mount in current code, you can give a example
>  command.
>  
>  2)The reason is the mount point is not correct and that cause storing in
>  wrong place in 2nd kernel.
>  
>  3) how do you fix it with code in this patch. Namely how to get the
>  mount point correctly.
>  
>  With the help of command example it should be easy to explain
>  what/why/how. So if you just show the view what bind mounted is, where
>  is the real location is if bind mount, I still need try it by myself to
>  get what's the correct mount point, but not get it directly from you
>  patch log.
>  
>  Thanks
>  Baoquan
>   
Thanks for your suggestion. Will modify the commit log as what you said.

Thanks
Minfei

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Baoquan He]

On 04/08/15 at 02:52pm, Minfei Huang wrote:
>  > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > > index 2ad528e..75d7673 100755
>  > > --- a/kdump-lib.sh
>  > > +++ b/kdump-lib.sh
>  > > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  > >  
>  > >  get_mntpoint_from_target()
>  > >  {
>  > > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > +    for _mnt in $(findmnt -k -n -r -o TARGET $1)
>  > > +    do
>  > > +        if ! is_bind_mount $_mnt; then
>  > > +            echo $_mnt
>  > > +            return
>  > 
>  > You make a change against non bind mount case. non bind mount don't get
>  > a mntpoint any more. Is that OK? And I don't see you explain it in patch
>  > log.
>  > 
>  
>  Yes, the function get_mntpoint_from_target may fail, if all of the mount
>  points are in bind mode. If so, kdump will raise the error message, and
>  kill itself. 
No, I mean a normal machine, just on my personal PC. I plan take a
kdump. Then here it returned a mntpoint from get_mntpoint_from_target,
but now it doesn't since it's not bind mount. Why it does't matter,
could you also explain it? Above what you mentioned is another issue.

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/08/15 at 04:41pm, Baoquan He wrote:
>  On 04/08/15 at 02:52pm, Minfei Huang wrote:
>   > > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > > > index 2ad528e..75d7673 100755
>  > > > --- a/kdump-lib.sh
>  > > > +++ b/kdump-lib.sh
>  > > > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  > > >  
>  > > >  get_mntpoint_from_target()
>  > > >  {
>  > > > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > > +    for _mnt in $(findmnt -k -n -r -o TARGET $1)
>  > > > +    do
>  > > > +        if ! is_bind_mount $_mnt; then
>  > > > +            echo $_mnt
>  > > > +            return
>  > > 
>  > > You make a change against non bind mount case. non bind mount don't get
>  > > a mntpoint any more. Is that OK? And I don't see you explain it in patch
>  > > log.
>  > > 
>  > 
>  > Yes, the function get_mntpoint_from_target may fail, if all of the mount
>  > points are in bind mode. If so, kdump will raise the error message, and
>  > kill itself.
>  
>  No, I mean a normal machine, just on my personal PC. I plan take a
>  kdump. Then here it returned a mntpoint from get_mntpoint_from_target,
>  but now it doesn't since it's not bind mount. Why it does't matter,
>  could you also explain it? Above what you mentioned is another issue. 
Hi, bao.

Ok, I will add the log to explain the case that get_mntpoint_from_target
return NULL.

Thanks
Minfei

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Dave Young]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  The filesystem support the device to be mounted different mount
> points.
>  The root path in the device may be different, if the mount point is
>  mounted by bind mode. In order to dump core correctly, we should find
>  the root path in the device.
>  
>  Following is the case that device is mounted by bind mode.
>  
>  TARGET    SOURCE   FSTYPE OPTIONS
>  /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  TARGET        SOURCE         FSTYPE OPTIONS
>  /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  
>  We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  the other word, the /mnt/bind-dir points to the /var directory in the
>  /dev/vda.
>  The /mnt/ext4 is the root path in the device.
>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  ---
>   kdump-lib.sh | 11 ++++++++++-
>   mkdumprd     |  8 ++------
>   2 files changed, 12 insertions(+), 7 deletions(-)
>  
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index 2ad528e..75d7673 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -135,7 +135,16 @@ get_fs_type_from_target()
>   
>   get_mntpoint_from_target()
>   {
>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  +    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 
Per discussion, we should limit the function only to atomic case.

So it should be like below:

get_mntpoint_from_target(){
if (!atomic)
  echo $(findmnt -k -f -n -r -o TARGET $1)
else {
 ...
}
}

>   }
>   
>   # get_option_value <option_name>
>  diff --git a/mkdumprd b/mkdumprd
>  index a8f9cbb..7fdcebf 100644
>  --- a/mkdumprd
>  +++ b/mkdumprd
>  @@ -100,7 +100,7 @@ to_mount() {
>       local _dev=$1 _source _target _fstype _options _mntopts _pdev
>   
>       _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  +    _target=$(get_mntpoint_from_target $_dev)
>       # mount under /sysroot if dump to root disk or mount under
>       #/kdumproot/$_target in other cases in 2nd kernel. systemd
>       #will be in charge to umount it.
>  @@ -144,10 +144,6 @@ to_mount() {
>       echo "$_pdev $_mntopts"
>   }
>   
>  -to_mount_point() {
>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  -}
>  -
>   is_readonly_mount() {
>       local _mnt
>       _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>   #Function: get_fs_size
>   #$1=dump target
>   get_fs_size() {
>  -    local _mnt=$(to_mount_point $1)
>  +    local _mnt=$(get_mntpoint_from_target $1)
>       echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')
>   }
>   
>  -- 
>  1.9.3
>

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/09/15 at 10:46am, Dave Young wrote:
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > The filesystem support the device to be mounted different mount points.
>  > The root path in the device may be different, if the mount point is
>  > mounted by bind mode. In order to dump core correctly, we should find
>  > the root path in the device.
>  > 
>  > Following is the case that device is mounted by bind mode.
>  > 
>  > TARGET    SOURCE   FSTYPE OPTIONS
>  > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > TARGET        SOURCE         FSTYPE OPTIONS
>  > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > 
>  > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > the other word, the /mnt/bind-dir points to the /var directory in the
>  > /dev/vda.
>  > The /mnt/ext4 is the root path in the device.
>  > 
>  > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > ---
>  >  kdump-lib.sh | 11 ++++++++++-
>  >  mkdumprd     |  8 ++------
>  >  2 files changed, 12 insertions(+), 7 deletions(-)
>  > 
>  > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > index 2ad528e..75d7673 100755
>  > --- a/kdump-lib.sh
>  > +++ b/kdump-lib.sh
>  > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  >  
>  >  get_mntpoint_from_target()
>  >  {
>  > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > +    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
>  
>  Per discussion, we should limit the function only to atomic case.
>  
>  So it should be like below:
>  
>  get_mntpoint_from_target(){
>  if (!atomic)
>    echo $(findmnt -k -f -n -r -o TARGET $1)
>  else {
>   ...
>  }
>  } 
It does not impact on the general system, so there is no limitation
for this function.

Thanks
Minfei

>  
>  >  }
>  >  
>  >  # get_option_value <option_name>
>  > diff --git a/mkdumprd b/mkdumprd
>  > index a8f9cbb..7fdcebf 100644
>  > --- a/mkdumprd
>  > +++ b/mkdumprd
>  > @@ -100,7 +100,7 @@ to_mount() {
>  >      local _dev=$1 _source _target _fstype _options _mntopts _pdev
>  >  
>  >      _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  > -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  > +    _target=$(get_mntpoint_from_target $_dev)
>  >      # mount under /sysroot if dump to root disk or mount under
>  >      #/kdumproot/$_target in other cases in 2nd kernel. systemd
>  >      #will be in charge to umount it.
>  > @@ -144,10 +144,6 @@ to_mount() {
>  >      echo "$_pdev $_mntopts"
>  >  }
>  >  
>  > -to_mount_point() {
>  > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > -}
>  > -
>  >  is_readonly_mount() {
>  >      local _mnt
>  >      _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  > @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>  >  #Function: get_fs_size
>  >  #$1=dump target
>  >  get_fs_size() {
>  > -    local _mnt=$(to_mount_point $1)
>  > +    local _mnt=$(get_mntpoint_from_target $1)
>  >      echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print
> $4}')
>  >  }
>  >  
>  > -- 
>  > 1.9.3
>  >

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Dave Young]

On 04/09/15 at 10:55am, Minfei Huang wrote:
>  On 04/09/15 at 10:46am, Dave Young wrote:
>  > On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > > The filesystem support the device to be mounted different mount points.
>  > > The root path in the device may be different, if the mount point is
>  > > mounted by bind mode. In order to dump core correctly, we should find
>  > > the root path in the device.
>  > > 
>  > > Following is the case that device is mounted by bind mode.
>  > > 
>  > > TARGET    SOURCE   FSTYPE OPTIONS
>  > > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > > TARGET        SOURCE         FSTYPE OPTIONS
>  > > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > > 
>  > > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > > the other word, the /mnt/bind-dir points to the /var directory in the
>  > > /dev/vda.
>  > > The /mnt/ext4 is the root path in the device.
>  > > 
>  > > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > > ---
>  > >  kdump-lib.sh | 11 ++++++++++-
>  > >  mkdumprd     |  8 ++------
>  > >  2 files changed, 12 insertions(+), 7 deletions(-)
>  > > 
>  > > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > > index 2ad528e..75d7673 100755
>  > > --- a/kdump-lib.sh
>  > > +++ b/kdump-lib.sh
>  > > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  > >  
>  > >  get_mntpoint_from_target()
>  > >  {
>  > > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > +    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
>  > 
>  > Per discussion, we should limit the function only to atomic case.
>  > 
>  > So it should be like below:
>  > 
>  > get_mntpoint_from_target(){
>  > if (!atomic)
>  >   echo $(findmnt -k -f -n -r -o TARGET $1)
>  > else {
>  >  ...
>  > }
>  > }
>  
>  It does not impact on the general system, so there is no limitation
>  for this function. 
You assume it does not, but it could, the code flow is different from old one.

I still do not trust is_bind_mnt though we have no other better way for atomic..

>  
>  Thanks
>  Minfei
>  
>  > 
>  > >  }
>  > >  
>  > >  # get_option_value <option_name>
>  > > diff --git a/mkdumprd b/mkdumprd
>  > > index a8f9cbb..7fdcebf 100644
>  > > --- a/mkdumprd
>  > > +++ b/mkdumprd
>  > > @@ -100,7 +100,7 @@ to_mount() {
>  > >      local _dev=$1 _source _target _fstype _options _mntopts _pdev
>  > >  
>  > >      _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  > > -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  > > +    _target=$(get_mntpoint_from_target $_dev)
>  > >      # mount under /sysroot if dump to root disk or mount under
>  > >      #/kdumproot/$_target in other cases in 2nd kernel. systemd
>  > >      #will be in charge to umount it.
>  > > @@ -144,10 +144,6 @@ to_mount() {
>  > >      echo "$_pdev $_mntopts"
>  > >  }
>  > >  
>  > > -to_mount_point() {
>  > > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > -}
>  > > -
>  > >  is_readonly_mount() {
>  > >      local _mnt
>  > >      _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  > > @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>  > >  #Function: get_fs_size
>  > >  #$1=dump target
>  > >  get_fs_size() {
>  > > -    local _mnt=$(to_mount_point $1)
>  > > +    local _mnt=$(get_mntpoint_from_target $1)
>  > >      echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print
> $4}')
>  > >  }
>  > >  
>  > > -- 
>  > > 1.9.3
>  > >

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

On 04/09/15 at 11:00am, Dave Young wrote:
>  On 04/09/15 at 10:55am, Minfei Huang wrote:
>  > On 04/09/15 at 10:46am, Dave Young wrote:
>  > > On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > > > The filesystem support the device to be mounted different mount points.
>  > > > The root path in the device may be different, if the mount point is
>  > > > mounted by bind mode. In order to dump core correctly, we should find
>  > > > the root path in the device.
>  > > > 
>  > > > Following is the case that device is mounted by bind mode.
>  > > > 
>  > > > TARGET    SOURCE   FSTYPE OPTIONS
>  > > > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > > > TARGET        SOURCE         FSTYPE OPTIONS
>  > > > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  > > > 
>  > > > We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  > > > the other word, the /mnt/bind-dir points to the /var directory in the
>  > > > /dev/vda.
>  > > > The /mnt/ext4 is the root path in the device.
>  > > > 
>  > > > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > > > ---
>  > > >  kdump-lib.sh | 11 ++++++++++-
>  > > >  mkdumprd     |  8 ++------
>  > > >  2 files changed, 12 insertions(+), 7 deletions(-)
>  > > > 
>  > > > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > > > index 2ad528e..75d7673 100755
>  > > > --- a/kdump-lib.sh
>  > > > +++ b/kdump-lib.sh
>  > > > @@ -135,7 +135,16 @@ get_fs_type_from_target()
>  > > >  
>  > > >  get_mntpoint_from_target()
>  > > >  {
>  > > > -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > > +    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
>  > > 
>  > > Per discussion, we should limit the function only to atomic case.
>  > > 
>  > > So it should be like below:
>  > > 
>  > > get_mntpoint_from_target(){
>  > > if (!atomic)
>  > >   echo $(findmnt -k -f -n -r -o TARGET $1)
>  > > else {
>  > >  ...
>  > > }
>  > > }
>  > 
>  > It does not impact on the general system, so there is no limitation
>  > for this function.
>  
>  You assume it does not, but it could, the code flow is different from old one.
>  
>  I still do not trust is_bind_mnt though we have no other better way for atomic..
>   
I am fine with it to add limitation. Will add it in next posting patch.

Thanks
Minfei

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Dave Young]

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  The filesystem support the device to be mounted different mount
> points.
>  The root path in the device may be different, if the mount point is
>  mounted by bind mode. In order to dump core correctly, we should find
>  the root path in the device.
>  
>  Following is the case that device is mounted by bind mode.
>  
>  TARGET    SOURCE   FSTYPE OPTIONS
>  /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  TARGET        SOURCE         FSTYPE OPTIONS
>  /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache
>  
>  We can find that /mnt/bind-dir is mounted in the path /dev/vda[/var], in
>  the other word, the /mnt/bind-dir points to the /var directory in the
>  /dev/vda.
>  The /mnt/ext4 is the root path in the device.
>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  ---
>   kdump-lib.sh | 11 ++++++++++-
>   mkdumprd     |  8 ++------
>   2 files changed, 12 insertions(+), 7 deletions(-)
>  
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index 2ad528e..75d7673 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -135,7 +135,16 @@ get_fs_type_from_target()
>   
>   get_mntpoint_from_target()
>   { 
Also, for any new functions, there should be code comments to describe
the function itself, the input params, the output etc.

Ditto to other functions you introduced like trimming mnt point from path.

>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  +    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
>   }
>   
>   # get_option_value <option_name>
>  diff --git a/mkdumprd b/mkdumprd
>  index a8f9cbb..7fdcebf 100644
>  --- a/mkdumprd
>  +++ b/mkdumprd
>  @@ -100,7 +100,7 @@ to_mount() {
>       local _dev=$1 _source _target _fstype _options _mntopts _pdev
>   
>       _source=$(findmnt -k -f -n -r -o SOURCE $_dev)
>  -    _target=$(findmnt -k -f -n -r -o TARGET $_dev)
>  +    _target=$(get_mntpoint_from_target $_dev)
>       # mount under /sysroot if dump to root disk or mount under
>       #/kdumproot/$_target in other cases in 2nd kernel. systemd
>       #will be in charge to umount it.
>  @@ -144,10 +144,6 @@ to_mount() {
>       echo "$_pdev $_mntopts"
>   }
>   
>  -to_mount_point() {
>  -    echo $(findmnt -k -f -n -r -o TARGET $1)
>  -}
>  -
>   is_readonly_mount() {
>       local _mnt
>       _mnt=$(findmnt -k -f -n -r -o OPTIONS $1)
>  @@ -201,7 +197,7 @@ mkdir_save_path_ssh()
>   #Function: get_fs_size
>   #$1=dump target
>   get_fs_size() {
>  -    local _mnt=$(to_mount_point $1)
>  +    local _mnt=$(get_mntpoint_from_target $1)
>       echo -n $(df -P "${_mnt}/$SAVE_PATH"|tail -1|awk '{print $4}')
>   }
>   
>  -- 
>  1.9.3
>

[PATCH 2/3 v2] kdump-lib: Get the mount point correctly, if the device has several mount point

[Minfei Huang]

Hi, Dave, Bao.

I will re-post a new patch according to Dave's suggestion.

Thank you all for reviewing.

Thanks
Minfei

On 04/09/15 at 10:59am, Dave Young wrote:
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > The filesystem support the device to be mounted different mount points.
>  > The root path in the device may be different, if the mount point is
>  > mounted by bind mode. In order to dump core correctly, we should find
>  > the root path in the device.
>  > 
>  > Following is the case that device is mounted by bind mode.
>  > 
>  > TARGET    SOURCE   FSTYPE OPTIONS
>  > /mnt/ext4 /dev/vda btrfs  rw,relatime,seclabel,space_cache
>  > TARGET        SOURCE         FSTYPE OPTIONS
>  > /mnt/bind-dir /dev/vda[/var] btrfs  rw,relatime,seclabel,space_cache

[PATCH 3/3 v2] dracut-module-setup: Enhance kdump to support the bind mounted feature in Atomic

[Minfei Huang]

The kdump will dump the core in incorrect target directory, if the
target is bind mounted.

The kdump cann't parse the bind mounted path, if we specifies the vale
"path /var/crash" in the /etc/kdump.conf.

To correct dumping target, we can construct the real dumping path in
Atomic, which contains two part, one bind mounted path, the other
specified dump target.

Following is an example:
    -bash-4.2# cat /etc/kdump.conf | grep ^path
    path /var/crash

    -bash-4.2# findmnt /var | tail -n 1 | awk '{print $2}'
    /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var]

    -bash-4.2# findmnt -v /var | tail -n 1 | awk '{print $2}'
    /dev/mapper/atomicos-root

Then we can found it that the real path of dumping core is
/ostree/deploy/rhel-atomic-host/var/crash.

Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
---
 dracut-module-setup.sh | 39 ++++++++++++++++++++++++++++++++++-----
 kdump-lib.sh           |  5 +++++
 mkdumprd               | 24 +++++++++++++++++++++++-
 3 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 477ede1..7915b82 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -311,8 +311,7 @@ kdump_install_net() {
 default_dump_target_install_conf()
 {
     local _target _fstype
-    local _mntpoint
-    local _save_path
+    local _mntpoint _save_path
 
     is_user_configured_dump_target && return
 
@@ -321,6 +320,17 @@ default_dump_target_install_conf()
 
     _mntpoint=$(get_mntpoint_from_path $_save_path)
     _target=$(get_target_from_path $_save_path)
+
+    if is_atomic && is_bind_mount $_mntpoint; then
+        _save_path=$(cut_out_substring $_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/$_save_path
+    fi
+
     if [ "$_mntpoint" != "/" ]; then
         _fstype=$(get_fs_type_from_target $_target)
 
@@ -332,14 +342,30 @@ default_dump_target_install_conf()
         fi
 
         echo "$_fstype $_target" >> ${initdir}/tmp/$$-kdump.conf
-
         _save_path=$(cut_out_substring $_save_path $_mntpoint)
+    fi
+
+    sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
+    echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
+}
+
+adjust_bind_mount_path()
+{
+    local _target=$1
+    local _save_path=$(get_option_value "path")
+    [ -z "$_save_path" ] && _save_path=$DEFAULT_PATH
+
+    local _absolute_save_path=$(get_mntpoint_from_target $_target)/$_save_path
+    local _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
+
+    if is_bind_mount $_mntpoint; then
+        _save_path=$(cut_out_substring $_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
         sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
         echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
     fi
-
 }
 
 #install kdump.conf and what user specifies in kdump.conf
@@ -353,6 +379,9 @@ kdump_install_conf() {
         case "$config_opt" in
         ext[234]|xfs|btrfs|minix|raw)
             sed -i -e "s#^$config_opt[[:space:]]\+$config_val#$config_opt
$(kdump_to_udev_name $config_val)#" ${initdir}/tmp/$$-kdump.conf
+            if is_atomic; then
+                adjust_bind_mount_path "$config_val"
+            fi
             ;;
         ssh|nfs)
             kdump_install_net "$config_val"
diff --git a/kdump-lib.sh b/kdump-lib.sh
index 75d7673..8aa0da4 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -237,3 +237,8 @@ cut_out_substring()
     local _sub_str=$(echo $2|sed "s#/\{1,\}#/#g")
     echo ${_main_str#*"$_sub_str"}
 }
+
+is_atomic()
+{
+    grep -q "ostree" /proc/cmdline
+}
diff --git a/mkdumprd b/mkdumprd
index 7fdcebf..d7d006f 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -359,6 +359,17 @@ handle_default_dump_target()
 
     _mntpoint=$(get_mntpoint_from_path $SAVE_PATH)
     _target=$(get_target_from_path $SAVE_PATH)
+
+    if is_atomic && is_bind_mount $_mntpoint; then
+        SAVE_PATH=$(cut_out_substring $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/$SAVE_PATH
+    fi
+
     if [ "$_mntpoint" != "/" ]; then
         SAVE_PATH=$(cut_out_substring $SAVE_PATH $_mntpoint)
         _fstype=$(get_fs_type_from_target $_target)
@@ -530,8 +541,19 @@ do
         if [ "$config_opt" = "nfs" ]; then
             add_dracut_module "nfs"
         fi
+
+        _absolute_save_path=$(make_absolute_save_path $config_val)
+        if is_atomic; then
+            _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
+            if is_bind_mount $_mntpoint; then
+                SAVE_PATH=$(cut_out_substring $_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
+            fi
+        fi
+
         add_mount "$config_val"
-        check_save_path_fs $(make_absolute_save_path $config_val)
+        check_save_path_fs $_absolute_save_path
         check_size fs $config_val
         ;;
     raw)
-- 
1.9.3

[PATCH 3/3 v2] dracut-module-setup: Enhance kdump to support the bind mounted feature in Atomic

[Baoquan He]

If I understand correctly, this patch contains 2 parts. The 1st part
is to make check_save_path_fs works well. The 2nd part is to store
correct path into initramfs.

If that's true could you please split it into 2 patches and describe
both of them separately?

Thanks
Baoquan

On 04/08/15 at 12:30am, Minfei Huang wrote:
>  The kdump will dump the core in incorrect target directory, if the
>  target is bind mounted.
>  
>  The kdump cann't parse the bind mounted path, if we specifies the vale
>  "path /var/crash" in the /etc/kdump.conf.
>  
>  To correct dumping target, we can construct the real dumping path in
>  Atomic, which contains two part, one bind mounted path, the other
>  specified dump target.
>  
>  Following is an example:
>      -bash-4.2# cat /etc/kdump.conf | grep ^path
>      path /var/crash
>  
>      -bash-4.2# findmnt /var | tail -n 1 | awk '{print $2}'
>      /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var]
>  
>      -bash-4.2# findmnt -v /var | tail -n 1 | awk '{print $2}'
>      /dev/mapper/atomicos-root
>  
>  Then we can found it that the real path of dumping core is
>  /ostree/deploy/rhel-atomic-host/var/crash.
>  
>  Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  ---
>   dracut-module-setup.sh | 39 ++++++++++++++++++++++++++++++++++-----
>   kdump-lib.sh           |  5 +++++
>   mkdumprd               | 24 +++++++++++++++++++++++-
>   3 files changed, 62 insertions(+), 6 deletions(-)
>  
>  diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>  index 477ede1..7915b82 100755
>  --- a/dracut-module-setup.sh
>  +++ b/dracut-module-setup.sh
>  @@ -311,8 +311,7 @@ kdump_install_net() {
>   default_dump_target_install_conf()
>   {
>       local _target _fstype
>  -    local _mntpoint
>  -    local _save_path
>  +    local _mntpoint _save_path
>   
>       is_user_configured_dump_target && return
>   
>  @@ -321,6 +320,17 @@ default_dump_target_install_conf()
>   
>       _mntpoint=$(get_mntpoint_from_path $_save_path)
>       _target=$(get_target_from_path $_save_path)
>  +
>  +    if is_atomic && is_bind_mount $_mntpoint; then
>  +        _save_path=$(cut_out_substring $_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/$_save_path
>  +    fi
>  +
>       if [ "$_mntpoint" != "/" ]; then
>           _fstype=$(get_fs_type_from_target $_target)
>   
>  @@ -332,14 +342,30 @@ default_dump_target_install_conf()
>           fi
>   
>           echo "$_fstype $_target" >> ${initdir}/tmp/$$-kdump.conf
>  -
>           _save_path=$(cut_out_substring $_save_path $_mntpoint)
>  +    fi
>  +
>  +    sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
>  +    echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
>  +}
>  +
>  +adjust_bind_mount_path()
>  +{
>  +    local _target=$1
>  +    local _save_path=$(get_option_value "path")
>  +    [ -z "$_save_path" ] && _save_path=$DEFAULT_PATH
>  +
>  +    local _absolute_save_path=$(get_mntpoint_from_target $_target)/$_save_path
>  +    local _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
>  +
>  +    if is_bind_mount $_mntpoint; then
>  +        _save_path=$(cut_out_substring $_absolute_save_path $_mntpoint)
>  +        # the real dump path in the 2nd kernel, if the mount point is bind mounted.
>  +        _save_path=$(get_bind_mount_directory $_mntpoint)/$_save_path
>   
>  -        #erase the old path line, then insert the parsed path
>           sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
>           echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
>       fi
>  -
>   }
>   
>   #install kdump.conf and what user specifies in kdump.conf
>  @@ -353,6 +379,9 @@ kdump_install_conf() {
>           case "$config_opt" in
>           ext[234]|xfs|btrfs|minix|raw)
>               sed -i -e "s#^$config_opt[[:space:]]\+$config_val#$config_opt
> $(kdump_to_udev_name $config_val)#" ${initdir}/tmp/$$-kdump.conf
>  +            if is_atomic; then
>  +                adjust_bind_mount_path "$config_val"
>  +            fi
>               ;;
>           ssh|nfs)
>               kdump_install_net "$config_val"
>  diff --git a/kdump-lib.sh b/kdump-lib.sh
>  index 75d7673..8aa0da4 100755
>  --- a/kdump-lib.sh
>  +++ b/kdump-lib.sh
>  @@ -237,3 +237,8 @@ cut_out_substring()
>       local _sub_str=$(echo $2|sed "s#/\{1,\}#/#g")
>       echo ${_main_str#*"$_sub_str"}
>   }
>  +
>  +is_atomic()
>  +{
>  +    grep -q "ostree" /proc/cmdline
>  +}
>  diff --git a/mkdumprd b/mkdumprd
>  index 7fdcebf..d7d006f 100644
>  --- a/mkdumprd
>  +++ b/mkdumprd
>  @@ -359,6 +359,17 @@ handle_default_dump_target()
>   
>       _mntpoint=$(get_mntpoint_from_path $SAVE_PATH)
>       _target=$(get_target_from_path $SAVE_PATH)
>  +
>  +    if is_atomic && is_bind_mount $_mntpoint; then
>  +        SAVE_PATH=$(cut_out_substring $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/$SAVE_PATH
>  +    fi
>  +
>       if [ "$_mntpoint" != "/" ]; then
>           SAVE_PATH=$(cut_out_substring $SAVE_PATH $_mntpoint)
>           _fstype=$(get_fs_type_from_target $_target)
>  @@ -530,8 +541,19 @@ do
>           if [ "$config_opt" = "nfs" ]; then
>               add_dracut_module "nfs"
>           fi
>  +
>  +        _absolute_save_path=$(make_absolute_save_path $config_val)
>  +        if is_atomic; then
>  +            _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
>  +            if is_bind_mount $_mntpoint; then
>  +                SAVE_PATH=$(cut_out_substring $_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
>  +            fi
>  +        fi
>  +
>           add_mount "$config_val"
>  -        check_save_path_fs $(make_absolute_save_path $config_val)
>  +        check_save_path_fs $_absolute_save_path
>           check_size fs $config_val
>           ;;
>       raw)
>  -- 
>  1.9.3
>

[PATCH 3/3 v2] dracut-module-setup: Enhance kdump to support the bind mounted feature in Atomic

[Minfei Huang]

On 04/08/15 at 03:58pm, Baoquan He wrote:
>  If I understand correctly, this patch contains 2 parts. The 1st part
>  is to make check_save_path_fs works well. The 2nd part is to store
>  correct path into initramfs.
>  
>  If that's true could you please split it into 2 patches and describe
>  both of them separately?
>   
Ok, I am fine with it. Will bisect this patch.

Thanks
Minfei

>  Thanks
>  Baoquan
>  
>  On 04/08/15 at 12:30am, Minfei Huang wrote:
>  > The kdump will dump the core in incorrect target directory, if the
>  > target is bind mounted.
>  > 
>  > The kdump cann't parse the bind mounted path, if we specifies the vale
>  > "path /var/crash" in the /etc/kdump.conf.
>  > 
>  > To correct dumping target, we can construct the real dumping path in
>  > Atomic, which contains two part, one bind mounted path, the other
>  > specified dump target.
>  > 
>  > Following is an example:
>  >     -bash-4.2# cat /etc/kdump.conf | grep ^path
>  >     path /var/crash
>  > 
>  >     -bash-4.2# findmnt /var | tail -n 1 | awk '{print $2}'
>  >     /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var]
>  > 
>  >     -bash-4.2# findmnt -v /var | tail -n 1 | awk '{print $2}'
>  >     /dev/mapper/atomicos-root
>  > 
>  > Then we can found it that the real path of dumping core is
>  > /ostree/deploy/rhel-atomic-host/var/crash.
>  > 
>  > Signed-off-by: Minfei Huang <mhuang(a)redhat.com&gt;
>  > ---
>  >  dracut-module-setup.sh | 39 ++++++++++++++++++++++++++++++++++-----
>  >  kdump-lib.sh           |  5 +++++
>  >  mkdumprd               | 24 +++++++++++++++++++++++-
>  >  3 files changed, 62 insertions(+), 6 deletions(-)
>  > 
>  > diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>  > index 477ede1..7915b82 100755
>  > --- a/dracut-module-setup.sh
>  > +++ b/dracut-module-setup.sh
>  > @@ -311,8 +311,7 @@ kdump_install_net() {
>  >  default_dump_target_install_conf()
>  >  {
>  >      local _target _fstype
>  > -    local _mntpoint
>  > -    local _save_path
>  > +    local _mntpoint _save_path
>  >  
>  >      is_user_configured_dump_target && return
>  >  
>  > @@ -321,6 +320,17 @@ default_dump_target_install_conf()
>  >  
>  >      _mntpoint=$(get_mntpoint_from_path $_save_path)
>  >      _target=$(get_target_from_path $_save_path)
>  > +
>  > +    if is_atomic && is_bind_mount $_mntpoint; then
>  > +        _save_path=$(cut_out_substring $_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/$_save_path
>  > +    fi
>  > +
>  >      if [ "$_mntpoint" != "/" ]; then
>  >          _fstype=$(get_fs_type_from_target $_target)
>  >  
>  > @@ -332,14 +342,30 @@ default_dump_target_install_conf()
>  >          fi
>  >  
>  >          echo "$_fstype $_target" >> ${initdir}/tmp/$$-kdump.conf
>  > -
>  >          _save_path=$(cut_out_substring $_save_path $_mntpoint)
>  > +    fi
>  > +
>  > +    sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
>  > +    echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
>  > +}
>  > +
>  > +adjust_bind_mount_path()
>  > +{
>  > +    local _target=$1
>  > +    local _save_path=$(get_option_value "path")
>  > +    [ -z "$_save_path" ] && _save_path=$DEFAULT_PATH
>  > +
>  > +    local _absolute_save_path=$(get_mntpoint_from_target $_target)/$_save_path
>  > +    local _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
>  > +
>  > +    if is_bind_mount $_mntpoint; then
>  > +        _save_path=$(cut_out_substring $_absolute_save_path $_mntpoint)
>  > +        # the real dump path in the 2nd kernel, if the mount point is bind
> mounted.
>  > +        _save_path=$(get_bind_mount_directory $_mntpoint)/$_save_path
>  >  
>  > -        #erase the old path line, then insert the parsed path
>  >          sed -i "/^path/d" ${initdir}/tmp/$$-kdump.conf
>  >          echo "path $_save_path" >> ${initdir}/tmp/$$-kdump.conf
>  >      fi
>  > -
>  >  }
>  >  
>  >  #install kdump.conf and what user specifies in kdump.conf
>  > @@ -353,6 +379,9 @@ kdump_install_conf() {
>  >          case "$config_opt" in
>  >          ext[234]|xfs|btrfs|minix|raw)
>  >              sed -i -e "s#^$config_opt[[:space:]]\+$config_val#$config_opt
> $(kdump_to_udev_name $config_val)#" ${initdir}/tmp/$$-kdump.conf
>  > +            if is_atomic; then
>  > +                adjust_bind_mount_path "$config_val"
>  > +            fi
>  >              ;;
>  >          ssh|nfs)
>  >              kdump_install_net "$config_val"
>  > diff --git a/kdump-lib.sh b/kdump-lib.sh
>  > index 75d7673..8aa0da4 100755
>  > --- a/kdump-lib.sh
>  > +++ b/kdump-lib.sh
>  > @@ -237,3 +237,8 @@ cut_out_substring()
>  >      local _sub_str=$(echo $2|sed "s#/\{1,\}#/#g")
>  >      echo ${_main_str#*"$_sub_str"}
>  >  }
>  > +
>  > +is_atomic()
>  > +{
>  > +    grep -q "ostree" /proc/cmdline
>  > +}
>  > diff --git a/mkdumprd b/mkdumprd
>  > index 7fdcebf..d7d006f 100644
>  > --- a/mkdumprd
>  > +++ b/mkdumprd
>  > @@ -359,6 +359,17 @@ handle_default_dump_target()
>  >  
>  >      _mntpoint=$(get_mntpoint_from_path $SAVE_PATH)
>  >      _target=$(get_target_from_path $SAVE_PATH)
>  > +
>  > +    if is_atomic && is_bind_mount $_mntpoint; then
>  > +        SAVE_PATH=$(cut_out_substring $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/$SAVE_PATH
>  > +    fi
>  > +
>  >      if [ "$_mntpoint" != "/" ]; then
>  >          SAVE_PATH=$(cut_out_substring $SAVE_PATH $_mntpoint)
>  >          _fstype=$(get_fs_type_from_target $_target)
>  > @@ -530,8 +541,19 @@ do
>  >          if [ "$config_opt" = "nfs" ]; then
>  >              add_dracut_module "nfs"
>  >          fi
>  > +
>  > +        _absolute_save_path=$(make_absolute_save_path $config_val)
>  > +        if is_atomic; then
>  > +            _mntpoint=$(get_mntpoint_from_path $_absolute_save_path)
>  > +            if is_bind_mount $_mntpoint; then
>  > +                SAVE_PATH=$(cut_out_substring $_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
>  > +            fi
>  > +        fi
>  > +
>  >          add_mount "$config_val"
>  > -        check_save_path_fs $(make_absolute_save_path $config_val)
>  > +        check_save_path_fs $_absolute_save_path
>  >          check_size fs $config_val
>  >          ;;
>  >      raw)
>  > -- 
>  > 1.9.3
>  >