Support non-contiguous multi-extent files on the CPU/P2P read path - #11
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Rework the CPU/P2P read path to read files whose extents are not physically contiguous, instead of bailing out with ENOTSUP. For each file, coalesce physically-adjacent extents into runs and submit each run in iosize-sized commands (_submit_run), advancing the buffer pointer across runs so the file lands contiguously in memory. A tail command shorter than iosize is now handled, dropping the old divisibility requirement. This also simplifies the path: the _work/_range cooperative state machine and the per-device slbas/elbas arrays (struct fil_cpu_io) are gone. The completion callback (fil_io_cb) is now a plain reaper that tallies errors into device->io_errors, registered once per queue in _xnvme_setup rather than on every batch. _submit_device always drains the queue before returning, including on the error path, so no outstanding command is left referencing a buffer. Note: prep_time is no longer reported for CPU/P2P; extent resolution is now interleaved into submission and folded into io_time. Signed-off-by: Karl Bonde Torp <k.torp@samsung.com>
The CPU/P2P submit path computed io_nblocks = iosize / blocksize without checking that iosize is a multiple of the device LBA size, as the GPU path already does. A misconfigured iosize smaller than the LBA size yields io_nblocks == 0, hanging _submit_run and dividing by zero in _flush_run. Reject it up front with EINVAL, mirroring fil_gpu_submit. Signed-off-by: Karl Bonde Torp <k.torp@samsung.com>
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Reworks the CPU/P2P read path so it can read files whose extents are not physically contiguous, instead of bailing out with ENOTSUP. Also hardens the path against a misconfigured iosize that previously caused a hang and a divide-by-zero.