Re: DMAPI 2GB limit

[Dean Roehrich <roehrich@sgi.com>]

>From:  "James A Goodwin" <jagoodwi@us.ibm.com>
>We were noticing some EINVAL errors coming from dm_read_invis() on our XFS
>1.1 system.  It looks like the sys_dmapi_args_t structure that is used to
>pass data from the DMAPI library to the kernel is using long ints to store
>the offset and length of the read.  It turns out that we were trying to
>read some data just past a 2GB offset, and that value in a signed long int
>is interpreted as a fairly large negative number, which explains the EINVAL
>return code.
>
>Is this something that can be changed by recompiling with certain flags set
>(the kernel and the dmapi library), or am I simply hosed?

I think it needs more than a recompile.  Probably have to change the 'long' to
'unsigned long long'.  The library already uses large enough types, maybe
it'll work.

The bug list grows...

Dean