dax/fsdev: use __va(phys) for kaddr in direct_access

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Use __va(phys) instead of virt_addr + linear_offset for the kaddr
return in __fsdev_dax_direct_access(). The previous code added a
device-linear byte offset to virt_addr (which is __va of ranges[0]),
but for multi-range devices with physical gaps between ranges, this
linear arithmetic crosses the gap and produces a wrong kernel virtual
address. Using __va(phys) where phys comes from dax_pgoff_to_phys()
is correct for any range layout because the direct map translates
each physical address independently.

This leaves dev_dax->virt_addr write-only, so remove the field
(suggested by Dave Jiang).

Fixes: 759455848d ("dax: Save the kva from memremap")

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019ecc096de8-8bc254a7-d2cc-44b6-82b1-1394fda8bb41-000000@email.amazonses.com
Signed-off-by: Alison Schofield <alison.schofield@intel.com>

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This commit is contained in:

John Groves 2026-06-15 16:07:10 +00:00 • committed by Alison Schofield

parent f48884ac31

commit ff7c73fca7

2 changed files with 2 additions and 8 deletions

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2

drivers/dax/dax-private.h

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8

drivers/dax/fsdev.c

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