On Mon, Sep 02, 2013 at 08:20:02PM +0800, Robert Yang wrote: > > > On 09/02/2013 07:55 PM, Zheng Liu wrote: > >On Mon, Sep 02, 2013 at 02:46:33PM +0800, Robert Yang wrote: > >> > >> > >>On 09/01/2013 11:26 AM, Zheng Liu wrote: > >>>Hi Robert, > >>> > >>>On Wed, Aug 28, 2013 at 01:25:50PM +0800, Robert Yang wrote: > >>>>This option is used for adding the files from the root-directory to the > >>>>filesystem, it is similiar to genext2fs, but genext2fs doesn't fully > >>>>support ext4. > >>>> > >>>>* Questions > >>>> - Is such an option acceptable ? > >>>> > >>>> - Most of the code have been in debugfs/debugfs.c already, I moved them to > >>>> misc/util.c and modified them to let both mke2fs and debugfs can use them, > >>>> maybe we should put these code in another separate file ? > >>>> > >>>> - Where can I get the up-to-date development git repo, please? I think that > >>>> there would be conflicts with the dev git repo, I'd like to rebase it if I > >>>> can get the repo, currently, I'm using this one: > >>>> > >>>> http://git.kernel.org/cgit/fs/ext2/e2fsprogs.git > >>>> > >>>>* The size impact on misc/mke2fs: > >>>> 1,677,297 -> 1,728,110 (non stripped, about 50K increases) > >>>> 316,968 -> 325,160 (stripped, 8K increases) > >>>> > >>>>Please feel free to give your comments. > >>> > >>>If I understand correctly, after applied this patch set, we can copy > >>>some files from a directory that is indicated by '-d' option when we > >>>create a new ext4 file system. My concern is why we need to add this > >>>option? Without this option I can use 'mkfs.ext4 ${DEV}', 'mount ${DEV} > >>>${MNT}' and 'cp ${SRC} ${MNT}' to do the same thing. I am not > >>>convinced. Could you please describe more details for this patch set? > >>> > >> > >>Hi Zheng, > >> > >>Yes, you are right, we can run mkfs/mount/cp to do the same thing, > >>but the problem is that the "mount" command requires the root privilege, > >>but we may not have it when we are working on a sever (the mkfs doesn't > >>need the root privilege), for example > >> > >>$ dd if=/dev/zero of=test.img count=0 bs=1k seek=2M > >>$ mke2fs -t ext4 -F test.img -d <root-dir> > >> > >>Will create an ext4 image with the files copied without the root privilege. > > > >Interesting. As you said above, if you haven't the root privilege, you > >won't use this file system. But at least this file system will be used > >by some one who have the root privilege. He/she can do the rest of > >works. That means that you do 'dd/mke2fs' and he or she does > >'mount/cp'. I don't see any reason that all dirs and files must be > >created by mke2fs. Any real case that needs to do this? > > > > Hi Zheng, > > For example, in Linux embedded development, we usually create a filesystem > image which contains the linux embedded OS, this image can be used by qemu, > Live CD and so on. Ah, got it. After adding this option, you can create a USB Live CD directly and don't need to get the root privilege. Thanks for your explanation. - Zheng -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
