On Fri, Nov 01, 2013 at 08:29:26PM -0400, Jason Cipriani wrote:
> In blkdiscard in util-linux, at least since version 2.23, the
> following code is used to retrieve a device's physical sector size:
>
> uint64_t secsize;
> ioctl(fd, BLKSSZGET, &secsize);
>
> On my machine (Ubuntu 12.04 -- 3.2.0-55-generic-pae #85-Ubuntu SMP Wed
> Oct 2 14:03:15 UTC 2013 i686 i686 i386 GNU/Linux) this yields
> incorrect results as it seems a 32-bit int is expected, this causes
> subsequent sector alignment calculations in blkdiscard to be
> incorrect, which in turn causes blkdiscards trim ioctl's to fail in
> certain situations (or even worse, to trim the wrong blocks).
BLKSSZGET returns an int. If you look at the sources of util-linux
v2.23, you'll see it passes an int to BLKSSZGET in
sys-utils/blkdiscard.c
lib/blkdev.c
E2fsprogs also expects BLKSSZGET to return an int, and if you look at
the kernel sources, it very clearly returns an int.
The one place it doesn't is in sys-utils/blkdiscard.c, where as you
have noted, it is passing in a uint64 to BLKSSZGET. This looks like
it's a bug in sys-util/blkdiscard.c.
I'll send a proposed patch in the next e-mail message.
- Ted
--
To unsubscribe from this list: send the line "unsubscribe util-linux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
