On 01/08/2010 04:36 AM, Michal Novotny wrote:
This patch extends functionality of e{2|4}fsprogs to add
EXT2_FLAG_DIRECT flag to be passed to ext2fs_open2() function. This
internally calls open() function with O_DIRECT and handles the memory
alignment for both read and write operations.
In some cases direct access to devices is necessary and that was the
main reason for this patch to be done.
The main reason why this was done is that pygrub (used by xen
virtualization user-space package, it's a python version of grub for
paravirtualized guests) sometimes uses outdated version of grub.conf
file. Modifications to xen package were *not* enough because e2fsprogs
doesn't open the files directly. That's why I added EXT2_FLAG_DIRECT
support to make read/write operations work directly when passed. It's
been tested with pygrub like mentioned above for read operation and
it's working fine.
Signed-off-by: Michal Novotny <minovotn@xxxxxxxxxx>
Can you add to this some kind of data flow overview? Seems like a
really odd way to update this file system...
ric
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