Woody, this mailing list might not be the best place to discuss problems with YAFFS2. Saying that, a simple test could be to almost fully fill the YAFFS2 partition with a bunch of files, then read those files and make sure the files have the data they are supposed to have. Files should have sensible content in them (and are not just filled with zeroes). Also, I'm assuming that you already have some experience with YAFFS2, correct? Otherwise, maybe there is some requirement you haven't satisfied, like erasing all of your partition prior to using it?
On Mon, May 27, 2013 at 11:44 PM, Woody Wu <narkewo...@gmail.com> wrote: > On Tue, May 28, 2013 at 03:08:55AM +0100, Simon Slavin wrote: > > > > On 28 May 2013, at 2:37am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > How do you guys think about this: if NAND has an > > > IO problem, Yaffs2 should recover it or forward the error to > > > applications, right? > > > > Arguably. The file system can send an error back to the application. > > If something does that to SQLite3 SQLite3 will then return the result > > SQLITE_IOERR. If your program is correctly looking at the results > > returned from every SQLite3 API call, and it's not seeing that error, > > it would seem that yaffs2 is not doing the correct thing in this case. > > And from what you wrote it seems that rather than return an error to > > the program, yaffs2 prefers to write an error message to the console. > > Which is not what these things are meant to do. > > > > > > On 28 May 2013, at 2:40am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > Can you experts explains why a cheap Flash drive can harm an > > > application such as sqlite? > > > > > Does you mean these cheap drive was cheating > > > with ECC? > > > > It might just be so bad that it doesn't even realise something is > > wrong. You write something to sector 2336 and later read sector 2336 > > and expect to get the same thing back, but instead it returns the > > contents of sector 2338. Faulty hardware, perhaps. > > > > > Otherwise, filesystem should be able to capture IO error (fix > > > it or forward), right? > > > > If by 'forward' you mean to tell the application something went wrong, > > then right. But the file system might not know anything is wrong. It > > asked for sector 2336 and it got some data. How is it meant to know > > the data it retrieved came from the wrong place on the chip ? > > > > On 28 May 2013, at 2:33am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > How can I tell what's the current VFS that I was using? Thanks. > > > > Actually, just ignore that. You couldn't do anything about it even if > > you knew. From what Doctor Hipp wrote, I suspect that yaffs2 is > > faulty. > > > > Simon. > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > Very clear explained, Simon. Thanks. > > On the other hand, I still want to write some test code to exposure > Yaffs2's defects on my target. I already wrote a simple one, which just > repeatly write to a file and read back to compare its conents. Probably > it's too simple to trigger an error. After 72 hours, it haven't reported > any error. I really like to hear any suggestion on writing such a test > from your experts. Anyway, if the original case was really caused by > Yaffs2, I belive there must exist a test to capture it. Do you agree? > > -woody > > > > > > -- > woody > I can't go back to yesterday - because I was a different person then. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
