On 11/8/2021 11:27 PM, Christoph Hellwig wrote: > On Fri, Nov 05, 2021 at 07:16:38PM -0600, Jane Chu wrote: >> static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, >> void *addr, size_t bytes, struct iov_iter *i, int mode) >> { >> + phys_addr_t pmem_off; >> + size_t len, lead_off; >> + struct pmem_device *pmem = dax_get_private(dax_dev); >> + struct device *dev = pmem->bb.dev; >> + >> + if (unlikely(mode == DAX_OP_RECOVERY)) { >> + lead_off = (unsigned long)addr & ~PAGE_MASK; >> + len = PFN_PHYS(PFN_UP(lead_off + bytes)); >> + if (is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512, len)) { >> + if (lead_off || !(PAGE_ALIGNED(bytes))) { >> + dev_warn(dev, "Found poison, but addr(%p) and/or bytes(%#lx) not page aligned\n", >> + addr, bytes); >> + return (size_t) -EIO; >> + } >> + pmem_off = PFN_PHYS(pgoff) + pmem->data_offset; >> + if (pmem_clear_poison(pmem, pmem_off, bytes) != >> + BLK_STS_OK) >> + return (size_t) -EIO; >> + } >> + } > > This is in the wrong spot. As seen in my WIP series individual drivers > really should not hook into copying to and from the iter, because it > really is just one way to write to a nvdimm. How would dm-writecache > clear the errors with this scheme? How does dm-writecache detect and clear errors today? > > So IMHO going back to the separate recovery method as in your previous > patch really is the way to go. If/when the 64-bit store happens we > need to figure out a good way to clear the bad block list for that. > Yeah, the separate .dax_clear_poison API may not be arbitrarily called though. It must be followed by a 'write' operation, and so, unless we bind the two operations together, how do we enforce that to avoid silent data corruption? thanks! -jane -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel