linux-next end of partition problems?

["Luck, Tony" <tony.luck@intel.com>]

I noticed an odd message in the kernel log while booting
linux-next (tag: next-20090602[*])

attempt to access beyond end of device
sdb3: rw=0, want=31664120, limit=31664115

sdb3 is an ext3 filesystem mounted as /home

$ grep sdb3 /proc/partitions
   8       19   15832057 sdb3

I think /proc/partitions in in KBytes ... so the block (512 Byte)
count for this partition is 2*15832057 = 31664114 ... so the
"limit" in the console log looks reasonable, and since the "want"
is a bigger number, it does seem that we are trying to access
beyond the device.

BUT ... I don't get this message when booting a kernel built
from Linus' tree.

I see other weird stuff too.  Running a Linus kernel I get:
$ dd if=/dev/sdb3 of=/dev/null bs=1024
15832057+1 records in
15832057+1 records out

this neatly matches the reported size in /proc/partitions,
and no messages on the console.


With linux-next I see:
dd if=/dev/sdb3 of=/dev/null bs=1024
dd: reading `/dev/sdb3': Input/output error
15831936+0 records in
15831936+0 records out

and the same
attempt to access beyond end of device
sdb3: rw=0, want=31664120, limit=31664115


Note that on linux-next the "dd" gets the I/O error 121 blocks
earlier than we see end-of-file for this partition on the Linus
kernel.

-Tony

[*] grepping through boot logs I see this message appears in earlier
tags too.  All builds since next-20090428 show this problem (but I
wasn't being very diligent in April ... the previous build for
which I have a recorded console log was next-20090417).