Use the legacy BIO_RW_FAILFAST flag if it exists. If it is missing it
means we are running against a kernel with the newer API. We should
be able to enable some fairly smart behavior one we intergrate with the
new API, but until I get around to writing that code just remove the
flag entirely. It's not critical for correctness.
Kernel commit 6712ecf8f648118c3363c142196418f89a510b90 which removes the
size argument from bio_endio and bi_end_io, also removes the need to
handle partial IOs in the handler.
- Linux specific character device registration calls replaced with
the spl version for maximum portability between linux kernels.
- Added ZPIOS_NAME macro.
A compat ioctl handler for zpios was added which simply passes the
ioctl on to the usual handler. The IOWR macro's correctly handle
this. Additionally replace the use of 'struct timespec' which uses
longs internally and is therefore different sizes on 32-bit vs 64-bit
objects with 'struct zpios_timespec_t'. This custom structure uses
uint32_t types internally and is safe to pass through an ioctl. The
helper functions for this new type were also moved to a common place
so they may be used safely by the user or kernel code.
The intent here is to fully remove the previous Solaris thread
implementation so we don't need to simulate both Solaris kernel
and user space thread APIs. The few user space consumers of the
thread API have been updated to use the kthread API. In order
to support this we needed to more fully support the kthread API
and that means not doing crazy things like casting a thread id
to a pointer and using that as was done before. This first
implementation is not effecient but it does provide all the
corrent semantics. If/when performance becomes and issue we
can and should just natively adopt pthreads which is portable.
Let me finish by saying I'm not proud of any of this and I would
love to see it improved. However, this slow implementation does
at least provide all the correct kthread API semantics whereas
the previous method of casting the thread ID to a pointer was
dodgy at best.
Brian Behlendorf