Merge remote-tracking branch 'xfs/for-next'

[karo-tx-linux.git] / fs / dax.c

diff --git a/fs/dax.c b/fs/dax.c
index e38b2c589b541d8675177de2e5d2b65350120b70..d8d3cc9323a1658637341d280547cda96c670c9e 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -58,6 +58,26 @@ static void dax_unmap_atomic(struct block_device *bdev,
        blk_queue_exit(bdev->bd_queue);
 }
 
+struct page *read_dax_sector(struct block_device *bdev, sector_t n)
+{
+       struct page *page = alloc_pages(GFP_KERNEL, 0);
+       struct blk_dax_ctl dax = {
+               .size = PAGE_SIZE,
+               .sector = n & ~((((int) PAGE_SIZE) / 512) - 1),
+       };
+       long rc;
+
+       if (!page)
+               return ERR_PTR(-ENOMEM);
+
+       rc = dax_map_atomic(bdev, &dax);
+       if (rc < 0)
+               return ERR_PTR(rc);
+       memcpy_from_pmem(page_address(page), dax.addr, PAGE_SIZE);
+       dax_unmap_atomic(bdev, &dax);
+       return page;
+}
+
 /*
  * dax_clear_blocks() is called from within transaction context from XFS,
  * and hence this means the stack from this point must follow GFP_NOFS
@@ -343,7 +363,8 @@ static int dax_radix_entry(struct address_space *mapping, pgoff_t index,
        void *entry;
 
        WARN_ON_ONCE(pmd_entry && !dirty);
-       __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+       if (dirty)
+               __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
 
        spin_lock_irq(&mapping->tree_lock);