Make blkdev_issue_flush() behave correctly according to its required semantics - all volatile cached data is flushed to stable storage.
Eventually this needs to be replaced with something much more precise by tracking dirty DAX entries via the radix tree in struct address_space, but for now this gives us correctness even if the performance is quite bad. Userspace applications looking to avoid the fsync/msync penalty should consider more fine-grained flushing via the NVML library: https://github.com/pmem/nvml Signed-off-by: Ross Zwisler <ross.zwis...@linux.intel.com> --- drivers/nvdimm/pmem.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 0ba6a97..eea7997 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -80,7 +80,14 @@ static void pmem_make_request(struct request_queue *q, struct bio *bio) if (do_acct) nd_iostat_end(bio, start); - if (bio_data_dir(bio)) + if (bio->bi_rw & REQ_FLUSH) { + void __pmem *addr = pmem->virt_addr + pmem->data_offset; + size_t size = pmem->size - pmem->data_offset; + + wb_cache_pmem(addr, size); + } + + if (bio_data_dir(bio) || (bio->bi_rw & REQ_FLUSH)) wmb_pmem(); bio_endio(bio); @@ -189,6 +196,7 @@ static int pmem_attach_disk(struct device *dev, blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE); blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX); blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY); + blk_queue_flush(pmem->pmem_queue, REQ_FLUSH); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue); disk = alloc_disk(0); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
