ext4: let fiemap work with inline data

fiemap is used to find the disk layout of a file, as for inline data,
let us just pretend like a file with just one extent.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 35 insertions, 0 deletions

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index fc3629980925..bf5f77803885 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -15,6 +15,7 @@
 #include "ext4.h"
 #include "xattr.h"
 #include "truncate.h"
+#include <linux/fiemap.h>
 
 #define EXT4_XATTR_SYSTEM_DATA	"data"
 #define EXT4_MIN_INLINE_DATA_SIZE	((sizeof(__le32) * EXT4_N_BLOCKS))
@@ -1680,3 +1681,37 @@ int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
 
 	return ret;
 }
+
+int ext4_inline_data_fiemap(struct inode *inode,
+			    struct fiemap_extent_info *fieinfo,
+			    int *has_inline)
+{
+	__u64 physical = 0;
+	__u64 length;
+	__u32 flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_LAST;
+	int error = 0;
+	struct ext4_iloc iloc;
+
+	down_read(&EXT4_I(inode)->xattr_sem);
+	if (!ext4_has_inline_data(inode)) {
+		*has_inline = 0;
+		goto out;
+	}
+
+	error = ext4_get_inode_loc(inode, &iloc);
+	if (error)
+		goto out;
+
+	physical = iloc.bh->b_blocknr << inode->i_sb->s_blocksize_bits;
+	physical += (char *)ext4_raw_inode(&iloc) - iloc.bh->b_data;
+	physical += offsetof(struct ext4_inode, i_block);
+	length = i_size_read(inode);
+
+	if (physical)
+		error = fiemap_fill_next_extent(fieinfo, 0, physical,
+						length, flags);
+	brelse(iloc.bh);
+out:
+	up_read(&EXT4_I(inode)->xattr_sem);
+	return (error < 0 ? error : 0);
+}