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Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 4fd6b0c5c6b5..fc2e3141138b 100644
--- 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
@@ -338,7 +358,8 @@ 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);