Messages in this thread | | | From | Kay Sievers <> | Date | Tue, 19 Apr 2011 11:55:50 +0200 | Subject | Re: Linux 2.6.39-rc3 |
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On Tue, Apr 19, 2011 at 10:23, Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> wrote: > On Tue, 19 Apr 2011 00:57:27 +0200, Kay Sievers <kay.sievers@vrfy.org> wrote:
>> Just a simple question about this approach in general? A filesystem >> UUID can be changed on disk at any time (tune2fs -U ...). >> >> Your code looks like you copy the bytes to the in-kernel superblock >> structure without noticing any later changes on disk? How is that >> supposed to work? > > Isn't that true even for the fsid returned by statfs ?. IIUC tune2fs > won't change even the ext4_super_block.s_uuid .
What matter is that it's common practice today, to change labels on-disks of mounted filesystems.
There should probably be getter/setter (like generic ioctls, or whatever fits) for uuid/label of a mounted filesystem. That call would also update this new superblock info. Guess that's needed before the kernel can export such stuff in mountinfo.
So tools at least have a chance to do it right here, and the current on-disk edit can rightfully be deprecated. Exporting possible out-of-sync data, without the chance to update it without a "reboot" really doesn't sound convincing.
Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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