From 7901fd602af54133d0d39cb7ff09537e9defbace Mon Sep 17 00:00:00 2001

From: Ross Zwisler <ross.zwisler@linux.intel.com>

Date: Wed, 6 Sep 2017 16:18:58 -0700

Subject: [PATCH] dax: use PG_PMD_COLOUR instead of open coding

Git-commit: 917f34526c4123ccd93e4373719c645c85020a5a

Patch-Mainline: v4.14

References: FATE#323721

Use ~PG_PMD_COLOUR in dax_entry_waitqueue() instead of open coding an

equivalent page offset mask.

Link: http://lkml.kernel.org/r/20170822222436.18926-2-ross.zwisler@linux.intel.com

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>

Reviewed-by: Jan Kara <jack@suse.cz>

Cc: "Slusarz, Marcin" <marcin.slusarz@intel.com>

Cc: Alexander Viro <viro@zeniv.linux.org.uk>

Cc: Christoph Hellwig <hch@lst.de>

Cc: Dan Williams <dan.j.williams@intel.com>

Cc: Dave Chinner <david@fromorbit.com>

Cc: Matthew Wilcox <mawilcox@microsoft.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Acked-by: Hannes Reinecke <hare@suse.com>

---

 fs/dax.c | 11 ++++-------

 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c

index 742c13e..ce9e52e 100644

--- a/fs/dax.c

+++ b/fs/dax.c

@@ -43,6 +43,9 @@

 #define DAX_WAIT_TABLE_BITS 12

 #define DAX_WAIT_TABLE_ENTRIES (1 << DAX_WAIT_TABLE_BITS)

+/* The 'colour' (ie low bits) within a PMD of a page offset.  */

+#define PG_PMD_COLOUR	((PMD_SIZE >> PAGE_SHIFT) - 1)

+

 static wait_queue_head_t wait_table[DAX_WAIT_TABLE_ENTRIES];

 static int __init init_dax_wait_table(void)

@@ -99,7 +102,7 @@ static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping,

 	 * the range covered by the PMD map to the same bit lock.

 	 */

 	if (dax_is_pmd_entry(entry))

-		index &= ~((1UL << (PMD_SHIFT - PAGE_SHIFT)) - 1);

+		index &= ~PG_PMD_COLOUR;

 	key->mapping = mapping;

 	key->entry_start = index;

@@ -1175,12 +1178,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,

 }

 #ifdef CONFIG_FS_DAX_PMD

-/*

- * The 'colour' (ie low bits) within a PMD of a page offset.  This comes up

- * more often than one might expect in the below functions.

- */

-#define PG_PMD_COLOUR	((PMD_SIZE >> PAGE_SHIFT) - 1)

-

 static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,

 		loff_t pos, void *entry)

 {

-- 

1.8.5.6