[0/3] Migrate zero page DAX bit from DAX_ZERO_PAGE to XA_ZERO_ENTRY

Message

Amy Parker Nov. 29, 2020, 4:36 a.m. UTC

This patchset changes the representation in the NVDIMM DAX driver for a hole
in a file. It was previously represented by DAX_ZERO_PAGE, which was set as
1UL << 2.

Patch 1 migrates to XArray's XA_ZERO_ENTRY and registers the new
definition for XA_ZERO_PMD_ENTRY, which is used in dax_pmd_load_hole() to
represent whether a file is a PMD entry or a zero entry. Patch 2 shifts
the bit for DAX_EMPTY down from 1UL << 3 to 1UL << 2, as DAX_ZERO_ENTRY no
longer exists. Patch 3 corrects the terminology used above the definitions
for the DAX bits.

I tested this under xfstests with XFS+DAX for a 20 GiB NVDIMM and did not
observe any regressions.

Amy Parker (3):
 fs: dax.c: move fs hole signifier from DAX_ZERO_PAGE to XA_ZERO_ENTRY
 fs: dax.c: move down bit DAX_EMPTY
 fs: dax.c: correct terminology used in DAX bit definitions

 fs/dax.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)


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2.29.2