In this series, dax recovery code path is independent of that of normal write. Competing dax recovery threads are serialized, racing read threads are guaranteed not overlapping with the recovery process. In this phase, the recovery granularity is page, future patch will explore recovery in finer granularity. Changelog: v7 -> v8: - add a patch to teach the nfit driver to rely on mce->misc for poison granularity, suggested by Dan - add set_memory_present() helper to be invoked by set_mce_nospec() for better readibility, suggested by Dan - folded a trivial fix to comments in patch 2/NN, suggested by Boris, and more commit message comments from Boris - mode .recovery_write to dax_operation as dev_pagemap_ops is meant for device agnostic operations, suggested by Christoph - replace DAX_RECOVERY flag with enum dax_access_mode suggested by Dan - re-organized __pmem_direct_access as provided by Christoph - split [PATCH v7 4/6] into two patches: one introduces DAX_RECOVERY_WRITE, and the other introduces .recovery_write operation v6 -> v7: . incorporated comments from Christoph, and picked up a reviewed-by . add x86@xxxxxxxxxx per Boris . discovered pmem firmware doesn't reliably handle a request to clear poison over a large range (such as 2M), hence worked around the the feature by limiting the size of the requested range to kernel page size. v5->v6: . per Christoph, move set{clear}_mce_nospec() inline functions out of include/linux/set_memory.h and into arch/x86/mm/pat/set_memory.c file, so that no need to export _set_memory_present(). . per Christoph, ratelimit warning message in pmem_do_write() . per both Christoph and Dan, switch back to adding a flag to dax_direct_access() instead of embedding the flag in kvaddr . suggestions from Christoph for improving code structure and readability . per Dan, add .recovery_write to dev_pagemap.ops instead of adding it to dax_operations, such that, the DM layer doesn't need to be involved explicitly in dax recoovery write . per Dan, is_bad_pmem() takes a seqlock, so no need to place it under recovery_lock. Many thanks for both reviewers! v4->v5: Fixed build errors reported by kernel test robot v3->v4: Rebased to v5.17-rc1-81-g0280e3c58f92 References: v4 https://lore.kernel.org/lkml/20220126211116.860012-1-jane.chu@xxxxxxxxxx/T/ v3 https://lkml.org/lkml/2022/1/11/900 v2 https://lore.kernel.org/all/20211106011638.2613039-1-jane.chu@xxxxxxxxxx/ Disussions about marking poisoned page as 'np' https://lore.kernel.org/all/CAPcyv4hrXPb1tASBZUg-GgdVs0OOFKXMXLiHmktg_kFi7YBMyQ@xxxxxxxxxxxxxx/ Jane Chu (7): acpi/nfit: rely on mce->misc to determine poison granularity x86/mce: relocate set{clear}_mce_nospec() functions mce: fix set_mce_nospec to always unmap the whole page dax: introduce DAX_RECOVERY_WRITE dax access mode dax: add .recovery_write dax_operation pmem: refactor pmem_clear_poison() pmem: implement pmem_recovery_write() arch/x86/include/asm/set_memory.h | 52 -------- arch/x86/kernel/cpu/mce/core.c | 6 +- arch/x86/mm/pat/set_memory.c | 48 ++++++- drivers/acpi/nfit/mce.c | 4 +- drivers/dax/super.c | 14 +- drivers/md/dm-linear.c | 15 ++- drivers/md/dm-log-writes.c | 15 ++- drivers/md/dm-stripe.c | 15 ++- drivers/md/dm-target.c | 4 +- drivers/md/dm-writecache.c | 7 +- drivers/md/dm.c | 25 +++- drivers/nvdimm/pmem.c | 207 +++++++++++++++++++++--------- drivers/nvdimm/pmem.h | 6 +- drivers/s390/block/dcssblk.c | 9 +- fs/dax.c | 22 +++- fs/fuse/dax.c | 4 +- include/linux/dax.h | 22 +++- include/linux/device-mapper.h | 13 +- include/linux/set_memory.h | 10 +- tools/testing/nvdimm/pmem-dax.c | 3 +- 20 files changed, 351 insertions(+), 150 deletions(-) base-commit: 028192fea1de083f4f12bfb1eb7c4d7beb5c8ecd -- 2.18.4 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel