[PATCH 6/6] dm: Ensure dm honors DAXDEV_F_RECOVERY flag on dax only
From: Jane Chu <hidden>
Date: 2021-10-21 00:12:34
Also in:
dm-devel, linux-fsdevel, lkml, nvdimm
Subsystem:
device-mapper (lvm), the rest · Maintainers:
Alasdair Kergon, Mike Snitzer, Mikulas Patocka, Benjamin Marzinski, Linus Torvalds
dm_dax_direct_access() supports DAXDEV_F_RECOVERY, so it may translate a poisoned range. But if dm_dax_copy_to/from_iter() don't have a dax_copy_to/from_iter() foundation underneath, performing load/store over poisoned range is dangerous and should be avoided. Signed-off-by: Jane Chu <redacted> --- drivers/md/dm.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 764183ddebc1..5f7fe64d3c37 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c@@ -1058,6 +1058,8 @@ static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, if (!ti) goto out; if (!ti->type->dax_copy_from_iter) { + if (flags & DAXDEV_F_RECOVERY) + goto out; ret = copy_from_iter(addr, bytes, i); goto out; }
@@ -1082,6 +1084,8 @@ static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, if (!ti) goto out; if (!ti->type->dax_copy_to_iter) { + if (flags & DAXDEV_F_RECOVERY) + goto out; ret = copy_to_iter(addr, bytes, i); goto out; }
--
2.18.4