On Wed, 2007-11-28 at 16:42 +0900, Tejun Heo wrote: > Greg KH wrote: > > On Mon, Nov 26, 2007 at 08:31:16PM -0800, Andrew Morton wrote: > >> On Wed, 21 Nov 2007 15:16:59 -0700 Andrew Patterson <[EMAIL PROTECTED]> > >> wrote: > >> > >>> The buf in fs/sysfs.c:subsys_attr_store() does not seem to be updated > >>> correctly when returning a negative value (indicating that an error > >>> condition has occurred) is returned. If a negative value is returned, > >>> the next subsequent call to subsys_attr_store will have the contents of > >>> buf appended to the previous call. > >> subsys_attr_store() gets deleted by > >> http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/gregkh-01-driver/kset-kill-subsys-attr.patch > >> > >> So maybe we will soon accidentally fix whatever-this-is? Or maybe we will > >> faithfully maintain it. > > > > Yes, subsys attributes go away, but this is showing a bug in the sysfs > > core with attributes, not in the "middle" layers of attributes. > > > > I bounced the original bug report to Tejun, who has been changing the > > logic around this area to see if he sees anything that might be > > different now. > > > > Tejun? > > Weird, the problem is not reproducible here. > > # echo a > allow_restart > -bash: echo: write error: Invalid argument > [ 437.518024] buf_ptr = 0xffff810005e20000, buf = x > [ 437.518027] , count = 2 > # echo b > allow_restart > -bash: echo: write error: Invalid argument > [ 438.972973] buf_ptr = 0xffff81001be6f000, buf = y > [ 438.972976] , count = 2 > # echo c > allow_restart > -bash: echo: write error: Invalid argument > [ 440.539747] buf_ptr = 0xffff81001d4ba000, buf = z > [ 440.539750] , count = 2 > > Which is expected. On each open, sysfs_buffer is allocated with kzalloc > and the buffer is freed on close, so I don't see how it can happen. > Behavior for multiple write can be considered peculiar in that ppos is > essentially ignored and each write is passed just like brand new write > to ->store method but this too is the expected behavior. > > # (echo a; echo b; echo c) > allow_restart > [ 765.257132] buf_ptr = 0xffff81001be4f000, buf = a > [ 765.257135] , count = 2 > [ 765.285474] buf_ptr = 0xffff81001be4f000, buf = b > [ 765.285484] , count = 2 > [ 765.314002] buf_ptr = 0xffff81001be4f000, buf = c > [ 765.314004] , count = 2 > -bash: echo: write error: Invalid argument > -bash: echo: write error: Invalid argument > -bash: echo: write error: Invalid argument > > Andrew Petterson, can you please build 2.6.24-rc3 from clean source tree > and retry? >
I tried with clean 2.6.24-rc3 and get the same bad behavior. This is on an ia64 box, so maybe that is an issue. I can try on an x86 box as well. Oh, one other thing. I tried a "uname -r" to make sure I had the correct kernel booted and got: # uname -r 2.6.24-rc3 x y z # Andrew -- Andrew Patterson Hewlett-Packard - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
