[PATCH 2/3] dax: relocate dax_load_hole()

From: Ross Zwisler
Date: Wed Jun 07 2017 - 16:49:51 EST


dax_load_hole() will soon need to call dax_insert_mapping_entry(), so it
needs to be moved lower in dax.c so the definition exists.

Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
---
fs/dax.c | 88 ++++++++++++++++++++++++++++++++--------------------------------
1 file changed, 44 insertions(+), 44 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 2a6889b..66e0e93 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -469,50 +469,6 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
return __dax_invalidate_mapping_entry(mapping, index, false);
}

-/*
- * The user has performed a load from a hole in the file. Allocating
- * a new page in the file would cause excessive storage usage for
- * workloads with sparse files. We allocate a page cache page instead.
- * We'll kick it out of the page cache if it's ever written to,
- * otherwise it will simply fall out of the page cache under memory
- * pressure without ever having been dirtied.
- */
-static int dax_load_hole(struct address_space *mapping, void **entry,
- struct vm_fault *vmf)
-{
- struct inode *inode = mapping->host;
- struct page *page;
- int ret;
-
- /* Hole page already exists? Return it... */
- if (!radix_tree_exceptional_entry(*entry)) {
- page = *entry;
- goto finish_fault;
- }
-
- /* This will replace locked radix tree entry with a hole page */
- page = find_or_create_page(mapping, vmf->pgoff,
- vmf->gfp_mask | __GFP_ZERO);
- if (!page) {
- ret = VM_FAULT_OOM;
- goto out;
- }
-
-finish_fault:
- vmf->page = page;
- ret = finish_fault(vmf);
- vmf->page = NULL;
- *entry = page;
- if (!ret) {
- /* Grab reference for PTE that is now referencing the page */
- get_page(page);
- ret = VM_FAULT_NOPAGE;
- }
-out:
- trace_dax_load_hole(inode, vmf, ret);
- return ret;
-}
-
static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
sector_t sector, size_t size, struct page *to,
unsigned long vaddr)
@@ -936,6 +892,50 @@ int dax_pfn_mkwrite(struct vm_fault *vmf)
}
EXPORT_SYMBOL_GPL(dax_pfn_mkwrite);

+/*
+ * The user has performed a load from a hole in the file. Allocating
+ * a new page in the file would cause excessive storage usage for
+ * workloads with sparse files. We allocate a page cache page instead.
+ * We'll kick it out of the page cache if it's ever written to,
+ * otherwise it will simply fall out of the page cache under memory
+ * pressure without ever having been dirtied.
+ */
+static int dax_load_hole(struct address_space *mapping, void **entry,
+ struct vm_fault *vmf)
+{
+ struct inode *inode = mapping->host;
+ struct page *page;
+ int ret;
+
+ /* Hole page already exists? Return it... */
+ if (!radix_tree_exceptional_entry(*entry)) {
+ page = *entry;
+ goto finish_fault;
+ }
+
+ /* This will replace locked radix tree entry with a hole page */
+ page = find_or_create_page(mapping, vmf->pgoff,
+ vmf->gfp_mask | __GFP_ZERO);
+ if (!page) {
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+
+finish_fault:
+ vmf->page = page;
+ ret = finish_fault(vmf);
+ vmf->page = NULL;
+ *entry = page;
+ if (!ret) {
+ /* Grab reference for PTE that is now referencing the page */
+ get_page(page);
+ ret = VM_FAULT_NOPAGE;
+ }
+out:
+ trace_dax_load_hole(inode, vmf, ret);
+ return ret;
+}
+
static bool dax_range_is_aligned(struct block_device *bdev,
unsigned int offset, unsigned int length)
{
--
2.9.4