filesystem-dax: Do not request kaddr and pfn when not required

Some functions within fs/dax don't need to get local pointer kaddr
or variable pfn from direct_access. Using NULL instead of having to
pass in useless pointer or variable that caller then just throw away.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/fs/dax.c b/fs/dax.c
index 641192808bb69054a634b6f5b229c2ca25f308bf..959a53323fad0bf28234668e9a850e36c8fca54b 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -647,7 +647,6 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
 {
        void *vto, *kaddr;
        pgoff_t pgoff;
-       pfn_t pfn;
        long rc;
        int id;
 
@@ -656,7 +655,7 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
                return rc;
 
        id = dax_read_lock();
-       rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+       rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, NULL);
        if (rc < 0) {
                dax_read_unlock(id);
                return rc;
@@ -967,7 +966,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
 {
        const sector_t sector = dax_iomap_sector(iomap, pos);
        pgoff_t pgoff;
-       void *kaddr;
        int id, rc;
        long length;
 
@@ -976,7 +974,7 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
                return rc;
        id = dax_read_lock();
        length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
-                                  &kaddr, pfnp);
+                                  NULL, pfnp);
        if (length < 0) {
                rc = length;
                goto out;
@@ -1052,15 +1050,13 @@ int __dax_zero_page_range(struct block_device *bdev,
                pgoff_t pgoff;
                long rc, id;
                void *kaddr;
-               pfn_t pfn;
 
                rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
                if (rc)
                        return rc;
 
                id = dax_read_lock();
-               rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr,
-                               &pfn);
+               rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
                if (rc < 0) {
                        dax_read_unlock(id);
                        return rc;
@@ -1116,7 +1112,6 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
                ssize_t map_len;
                pgoff_t pgoff;
                void *kaddr;
-               pfn_t pfn;
 
                if (fatal_signal_pending(current)) {
                        ret = -EINTR;
@@ -1128,7 +1123,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
                        break;
 
                map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size),
-                               &kaddr, &pfn);
+                               &kaddr, NULL);
                if (map_len < 0) {
                        ret = map_len;
                        break;