Messages in this thread | | | Date | Wed, 29 Mar 2000 17:41:30 +0200 (CEST) | From | Andrea Arcangeli <> | Subject | Re: Is ReiserFS really a journaling file system, or is it really just a synchronous-metadata file system like BSD FFS? |
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On Wed, 29 Mar 2000, Chris Mason wrote:
>[ for protecting files from corrupt data ]
Yep. More precisely what I meant was to protect files from having random contents that was previously on disk before the first data write to the file (that's also _the_ security issue).
>> reiserfs should be able to provide that feature too without having data >> journaling with some additional care in the way the data is exposed to >> userspace (mount option probably). >> >I think I see what you mean...perhaps we could do this by updating the >stat data to reflect which blocks have actually been written. If we read
Yes, something like that. The end_io of the data bh can set a bitflag in the inode that means such block is not containing sniffable/random data anymore but that it contains something related to _such_ file.
>a file that is incomplete, we have a choice of truncating off the bad >data, or simply refusing to service any operations for that file. Or did >you intend something else (my idea wouldn't be zero cost).
Yes, it's definitely not zero cost (the inode gets dirtified also at the end_io of the data block) but it would take care at least of the security issue and of the completly random data in the file that is the bigger concern as far I can tell.
For full data integrity data journaling is necessary instead.
Andrea
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