dax: account DAX entries as nrpages
Simplify mapping_needs_writeback() by accounting DAX entries as pages
instead of exceptional entries.
Link: https://lkml.kernel.org/r/20201026151849.24232-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dax.c b/fs/dax.c
index 999f3f22..69216241 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -525,7 +525,7 @@ static void *grab_mapping_entry(struct xa_state *xas,
dax_disassociate_entry(entry, mapping, false);
xas_store(xas, NULL); /* undo the PMD join */
dax_wake_entry(xas, entry, true);
- mapping->nrexceptional--;
+ mapping->nrpages -= PG_PMD_NR;
entry = NULL;
xas_set(xas, index);
}
@@ -541,7 +541,7 @@ static void *grab_mapping_entry(struct xa_state *xas,
dax_lock_entry(xas, entry);
if (xas_error(xas))
goto out_unlock;
- mapping->nrexceptional++;
+ mapping->nrpages += 1UL << order;
}
out_unlock:
@@ -661,7 +661,7 @@ static int __dax_invalidate_entry(struct address_space *mapping,
goto out;
dax_disassociate_entry(entry, mapping, trunc);
xas_store(&xas, NULL);
- mapping->nrexceptional--;
+ mapping->nrpages -= 1UL << dax_entry_order(entry);
ret = 1;
out:
put_unlocked_entry(&xas, entry);
