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? -- tejun - 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/
