From 302a5e312b3a106fec49ba08da3f6545c9b7ee18 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Wed, 1 Nov 2017 16:36:37 +0100
Subject: [PATCH 09/20] dax: Inline dax_pmd_insert_mapping() into the callsite
Git-commit: 302a5e312b3a106fec49ba08da3f6545c9b7ee18
Patch-mainline: v4.15-rc1
References: fate#322879

dax_pmd_insert_mapping() has only one callsite and we will need to
further fine tune what it does for synchronous faults. Just inline it
into the callsite so that we don't have to pass awkward bools around.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/dax.c                      | 47 +++++++++++++++++--------------------------
 include/trace/events/fs_dax.h |  1 -
 2 files changed, 19 insertions(+), 29 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 5b20c6456926..675fab8ec41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1235,33 +1235,11 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
 }
 
 #ifdef CONFIG_FS_DAX_PMD
-static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
-		loff_t pos, void *entry)
-{
-	struct address_space *mapping = vmf->vma->vm_file->f_mapping;
-	const sector_t sector = dax_iomap_sector(iomap, pos);
-	struct inode *inode = mapping->host;
-	void *ret = NULL;
-	pfn_t pfn = {};
-	int rc;
-
-	rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
-	if (rc < 0)
-		goto fallback;
-
-	ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
-			RADIX_DAX_PMD);
-	if (IS_ERR(ret))
-		goto fallback;
-
-	trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
-	return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
-			pfn, vmf->flags & FAULT_FLAG_WRITE);
-
-fallback:
-	trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
-	return VM_FAULT_FALLBACK;
-}
+/*
+ * 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_load_hole(struct vm_fault *vmf, struct iomap *iomap,
 		void *entry)
@@ -1317,6 +1295,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
 	void *entry;
 	loff_t pos;
 	int error;
+	pfn_t pfn;
 
 	/*
 	 * Check whether offset isn't beyond end of file now. Caller is
@@ -1394,7 +1373,19 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
 
 	switch (iomap.type) {
 	case IOMAP_MAPPED:
-		result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry);
+		error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
+		if (error < 0)
+			goto finish_iomap;
+
+		entry = dax_insert_mapping_entry(mapping, vmf, entry,
+						dax_iomap_sector(&iomap, pos),
+						RADIX_DAX_PMD);
+		if (IS_ERR(entry))
+			goto finish_iomap;
+
+		trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
+		result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
+					    write);
 		break;
 	case IOMAP_UNWRITTEN:
 	case IOMAP_HOLE:
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index fbc4a06f7310..88a9d19b8ff8 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -148,7 +148,6 @@ DEFINE_EVENT(dax_pmd_insert_mapping_class, name, \
 	TP_ARGS(inode, vmf, length, pfn, radix_entry))
 
 DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping);
-DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping_fallback);
 
 DECLARE_EVENT_CLASS(dax_pte_fault_class,
 	TP_PROTO(struct inode *inode, struct vm_fault *vmf, int result),
-- 
2.12.3