Re: [PATCH 01/17] pramfs: documentation

Marco Stornelli
2011-01-08T08:20:42Z

On 07/01/2011 22:59, Tony Luck wrote:
> On Fri, Jan 7, 2011 at 12:30 PM, Marco Stornelli
> <marco.stornelli@gmail.com> wrote:
>> constraint). About the errors: pramfs does not maintain file data in the
>> page caches for normal file I/O, so no writeback, the read/write
>> operation are done with direct io and they are always sync. The data are
>> write protected in hw when the arch provide this facility (x86 does).
>> Inode contains a checksum and when there are problems they are marked as
>> bad. Superblock contains checksum and there is a redundant superblock.
>
> But you can still get pramfs inconsistencies if the system crashes at an
> inopportune moment. E.g. when making files you write the new inode to
> pramfs, and then you insert the entry into the directory. A crash between
> these two operations leaves an allocated inode that doesn't appear in
> any directory. Without a fsck option, it will be hard to see that you have
> this problem, and your only recovery option is to wipe *all* files by making
> a new filesystem.

Is it a problem if you lost some logs? However do you expect that fsck
in this case will drop the inode?