* Vincent Caron <vcaron@xxxxxxxxxxxxx> hat geschrieben: > Since I'm in userland and not locking > any on-disk data structure I'm reading, I wonder what kind of suprises I > should expect in the retrieved data. Exactly that kind of surprises, you're expecting anyways: Old data where committed data exist that has not been written to it's target location yet or data, that has been overwritten in mean time. Since there is almost no restriction on the "wrong" data (could be mp3, could be part of a ext2 image file looking exactly like the data you're expecting to see - no way to know for sure) you can see *anything*. For an ext2 fs with journal, you could try interpreting the journal and fixup your cache to bring it up to date like this: 1. Get a copy of the journal 2. Read the blocks you're interested in (i.e. do the normal traversing step). -> from time to time, get a new copy of the journal, check what changed, process the changes. This also means, you need to keep some meta data about when and where you got your data from, so you can actually fixup stuff. Remember: While traversing, you can read any kind of trash. 3. Upon completion of 2. get a final copy of the journal to bring your cache up-to-date. The funny thing about this aproach: By repeating step 3 you could keep your cache up to date without any need of retraversing the file system at any time again as long as your check interval is short enough so you don't miss any journal updates. I leave the details to you're implementation skills, since I don't know what your strategies in e2find are. Regards, Bodo _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
