Hi there. :) I've got a bit of a problem I'm hoping you can help me out with. This isn't exactly kernel-related, although it is Linux-related. I've posted here since LKML is generally frequented by competant people with strong and deep understandings of various systems. :) I've sent this to both linux-kernel and linux-fsdevel. My Ericsson Mobile Companion MC218 PDA runs Symbian EPOC v1.05, which does not correctly implement the FAT32 file system. I have absolutely no idea how I originally found this thread but http://web.archive.org/web/20030901104427/http://www.opendarwin.org/pipermail/hackers/2002-September/000284.html was what actually told me what was going on: > The issue is that when the Psion's OS (EPOC) creates a new directory, it doesn't zero out the entire sector, just writes the new entries followed by one starting with a zero byte (marking the end of the directory). This means that there's often garbage data after that zero marker. As far as I can tell, this is `legal', but different from what Windows does (zeroes out the entire sector first). As you might be aware, Linux takes the "entire sector zeroed? ok, end of directory" approach; when it sees a single zero byte Mr. vfat goes "ooh, anomaly", treats it like a glitch, and keeps reading. So, after passing a CompactFlash card between Linux and EPOC enough times, it becomes sufficiently wonky-fied enough that I see stuff like $ ls ????????.??? () was c.all even 720.p i number o.f a sioninit.ial ?!?"?#?? ) cannot. be exp and.a d nverted.to ssignmen.t ????????.??? /non-roc.ky- exp() wa.s c o it on.lin st() req.uir [...] ????????.??? ] learn.how hing, i.go or is ou.t o t) a cam.era ????????.??? able or.pro hstateme.nt or on th.is tanceof'. do [...] ??????.? argument.s ion prototyp.e.m uments ????????.??? argument.s ionnoino.pt prototyp.e.v ust admi.t, ?<??? aybe i w.ant ist.se ps serve.r w them e.ven ?t??????.? bject it seems. to pt?hiok@.ljq was not.a f `. ` bly disl.ike itial put to s.lee wisexore.xpr argumen.ts bout 900.ms itiveexp.res qrcode.php xpressio.n [etc...] Predictable. :P Thankfully TestDisk works in most situations like these (although it managed to find 7.1GB of data in a 640MB partition recently) and I can dump out the filesystem and... start again. Not ideal. :/ The person in the thread linked above was running OS X; Mach's FAT driver handled the situation okay, but the fsck utility bombed badly. Fortunately for them, it was easy to reverse the tool's internal rule prioritization to a configuration which preserved the files. Not so for me. The first time this occured I contacted the author of dosfsck, the utility that one would presumably handle correcting these kinds of issues, around April 1st 2013. For any of a hundred possible reasons, despite the fact that I contacted this person via both email and IRC twice, I have had no response or acknowledgement of my messages. I'm not going to surmise or presume anything from this; instead, I'm asking anyone who understands the FAT32 file system if they know of a utility which might be able to fix these issues, or if they might be otherwise able to help me out. I personally am NOT interested in writing a Pacman clone for FAT32; I took one look at the dosfsck internals, blinked a couple of times, and *bolted*; it is by no means similar to the OS X FAT32 fsck utility; it's way more complex, and has many more ideas about exactly how it'd like to chop up and dice my broken filesystem. xD After having to recently wipe my CF card I have been perhaps understandably motivated to again seek a solution to this problem. EPOCalypticFATfight.zip contains two disk images from my spare 16MB CF card which exhibit this problem; I can generate more very easily. IIRC, it also contains some screenshots of a disk utility running on the PDA showing the raw FAT corruption, along with the entire contents of stderr from a dosfsck run on an earlier card image. It can be grabbed from: https://www.box.com/s/393ywij49mdwfu1e8apu If you wouldn't mind carbon-copying asmqb7 at gmail (s/at/@/ ; s/gmail/gmail.com/) (<-- measures taken to work around email-blocking in mailing-list trawlers) in your reply(s), this would be much appreciated since at the moment I'm less than enthused by the idea of subscribing to LKML and being flooded with messages; I'd only end up hiding them from my inbox, wasting bandwidth. Thanks in advance!! -i336 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
