Btrfs: Add mount -o nodatasum to turn of file data checksumming

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e535c50e669b..11885cb114e2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -116,10 +116,13 @@ int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct btrfs_trans_handle *trans;
         char *kaddr;
-        int ret;
+        int ret = 0;
         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
         size_t offset = start - page_start;
 
+        if (btrfs_test_opt(root, NODATASUM))
+                return 0;
+
         mutex_lock(&root->fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, inode);
@@ -143,6 +146,9 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
         struct btrfs_path *path = NULL;
         u32 csum;
 
+        if (btrfs_test_opt(root, NODATASUM))
+                return 0;
+
         mutex_lock(&root->fs_info->fs_mutex);
         path = btrfs_alloc_path();
         item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);
@@ -176,6 +182,9 @@ int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
         u32 csum = ~(u32)0;
         unsigned long flags;
 
+        if (btrfs_test_opt(root, NODATASUM))
+                return 0;
+
         ret = get_state_private(em_tree, start, &private);
         local_irq_save(flags);
         kaddr = kmap_atomic(page, KM_IRQ0);