Libguestfs - Dec 2018 - Re: [PATCH] v2v: linux: improve regex for resume= entries (RHBZ#1651987)

Add few more characters for the devices of resume= entries in the
command line of grub: this way it is possible to match also /dev/mapper
devices.

This should require no further processing, since the names of the
/dev/mapper devices do not change after the conversion.
---
 v2v/convert_linux.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/v2v/convert_linux.ml b/v2v/convert_linux.ml
index be4905473..945c3aa32 100644
--- a/v2v/convert_linux.ml
+++ b/v2v/convert_linux.ml
@@ -1004,7 +1004,7 @@ let convert (g : G.guestfs) inspect source output rcaps   
List.flatten (List.map Array.to_list (List.map g#aug_match paths)) in
 
     (* Map device names for each entry. *)
-    let rex_resume = PCRE.compile "^resume=(/dev/[a-z\\d]+)(.*)$"
+    let rex_resume = PCRE.compile "^resume=(/dev/[-a-z\\d/_]+)(.*)$"
     and rex_device_cciss = PCRE.compile
"^/dev/(cciss/c\\d+d\\d+)(?:p(\\d+))?$"
     and rex_device = PCRE.compile "^/dev/([a-z]+)(\\d*)?$" in
 
-- 
2.17.2

On Wed, Dec 05, 2018 at 12:57:19PM +0100, Pino Toscano
wrote:
> Add few more characters for the devices of resume= entries in the
> command line of grub: this way it is possible to match also /dev/mapper
> devices.
> 
> This should require no further processing, since the names of the
> /dev/mapper devices do not change after the conversion.
Yes this is what worried me, but I think you're right.

Therefore, ACK.

Rich.
>  v2v/convert_linux.ml | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/v2v/convert_linux.ml b/v2v/convert_linux.ml
> index be4905473..945c3aa32 100644
> --- a/v2v/convert_linux.ml
> +++ b/v2v/convert_linux.ml
> @@ -1004,7 +1004,7 @@ let convert (g : G.guestfs) inspect source output
rcaps >        List.flatten (List.map Array.to_list (List.map g#aug_match
paths)) in
>  
>      (* Map device names for each entry. *)
> -    let rex_resume = PCRE.compile
"^resume=(/dev/[a-z\\d]+)(.*)$"
> +    let rex_resume = PCRE.compile
"^resume=(/dev/[-a-z\\d/_]+)(.*)$"
>      and rex_device_cciss = PCRE.compile
"^/dev/(cciss/c\\d+d\\d+)(?:p(\\d+))?$"
>      and rex_device = PCRE.compile "^/dev/([a-z]+)(\\d*)?$" in
>  
> -- 
> 2.17.2
> 
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-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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On Wednesday, 5 December 2018 13:01:40 CET Richard W.M. Jones
wrote:
> On Wed, Dec 05, 2018 at 12:57:19PM +0100, Pino Toscano wrote:
> > Add few more characters for the devices of resume= entries in the
> > command line of grub: this way it is possible to match also
/dev/mapper
> > devices.
> > 
> > This should require no further processing, since the names of the
> > /dev/mapper devices do not change after the conversion.
> 
> Yes this is what worried me, but I think you're right.
I wanted to add an explanation out of the commit message, but
apparently I overwrote it when re-exporting the patch...

At least in my experience, guests may use /dev/mapper entries also in
other places -- for example, a freshly installed Fedora 29 in VMware
ESXi has in /etc/fstab:

/dev/mapper/fedora_unused-root /                       xfs     defaults        0
0
UUID=<some_uuid>               /boot                   ext4    defaults   
1 2
/dev/mapper/fedora_unused-swap swap                    swap    defaults        0
0

Since the guest works fine (root & swap) after the conversion, and that
so far we had no reports of problems due to /dev/mapper entries not
changed, I thought that doing the same for resume= entries will cause
any trouble.

-- 
Pino Toscano