[11/19] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
diff mbox

Message ID 20171011200603.27442-12-jack@suse.cz
State New
Headers show

Commit Message

Jan Kara Oct. 11, 2017, 8:05 p.m. UTC
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to same some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/dax.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

Comments

Christoph Hellwig Oct. 13, 2017, 7:12 a.m. UTC | #1
Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Ross Zwisler Oct. 13, 2017, 7:26 p.m. UTC | #2
On Wed, Oct 11, 2017 at 10:05:55PM +0200, Jan Kara wrote:
> Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
> gets called for a write fault. With synchronous page faults we would
> like to insert clean radix tree entry and dirty it only once we call
> fdatasync() and update page tables to same some unnecessary cache
> flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks good.

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

Patch
diff mbox

diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@  static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
 static void *dax_insert_mapping_entry(struct address_space *mapping,
 				      struct vm_fault *vmf,
 				      void *entry, sector_t sector,
-				      unsigned long flags)
+				      unsigned long flags, bool dirty)
 {
 	struct radix_tree_root *page_tree = &mapping->page_tree;
 	void *new_entry;
 	pgoff_t index = vmf->pgoff;
 
-	if (vmf->flags & FAULT_FLAG_WRITE)
+	if (dirty)
 		__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
 
 	if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@  static void *dax_insert_mapping_entry(struct address_space *mapping,
 		entry = new_entry;
 	}
 
-	if (vmf->flags & FAULT_FLAG_WRITE)
+	if (dirty)
 		radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
 
 	spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@  static int dax_load_hole(struct address_space *mapping, void *entry,
 	}
 
 	entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
-			RADIX_DAX_ZERO_PAGE);
+			RADIX_DAX_ZERO_PAGE, false);
 	if (IS_ERR(entry2)) {
 		ret = VM_FAULT_SIGBUS;
 		goto out;
@@ -1182,7 +1182,7 @@  static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
 
 		entry = dax_insert_mapping_entry(mapping, vmf, entry,
 						 dax_iomap_sector(&iomap, pos),
-						 0);
+						 0, write);
 		if (IS_ERR(entry)) {
 			error = PTR_ERR(entry);
 			goto error_finish_iomap;
@@ -1258,7 +1258,7 @@  static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
 		goto fallback;
 
 	ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
-			RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+			RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
 	if (IS_ERR(ret))
 		goto fallback;
 
@@ -1379,7 +1379,7 @@  static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
 
 		entry = dax_insert_mapping_entry(mapping, vmf, entry,
 						dax_iomap_sector(&iomap, pos),
-						RADIX_DAX_PMD);
+						RADIX_DAX_PMD, write);
 		if (IS_ERR(entry))
 			goto finish_iomap;