Re: [PATCH] Use of getblk differs between locations

From: Anton Altaparmakov
Date: Mon Oct 10 2005 - 16:20:46 EST


On Mon, 10 Oct 2005, Glauber de Oliveira Costa wrote:
> I've just noticed that the use of sb_getblk differs between locations
> inside the kernel. To be precise, in some locations there are tests
> against its return value, and in some places there are not.
> According to the comments in __getblk definition, the tests are not
> necessary, as the function always return a buffer_head (maybe a wrong
> one),

If you had read the source code rather than just the comments you would
have seen that this is not true. It can return NULL (see
fs/buffer.c::__getblk_slow()). Certainly I would prefer to keep the
checks in NTFS, please. They may only be good for catching bugs but I
like catching bugs rather than segfaulting due to a NULL dereference.

Best regards,

Anton Altaparmakov <aia21 at> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on
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