unix_capture.c: mark regular files as sparse when appropriate

[wimlib] / src / unix_capture.c

diff --git a/src/unix_capture.c b/src/unix_capture.c
index eed38f62e29beb84503653c5bb0e4f5a7c2f26ff..1c207cb80eeab1d12d36775e9e901519849a9b2f 100644 (file)
--- a/src/unix_capture.c
+++ b/src/unix_capture.c
@@ -100,13 +100,21 @@ my_fdopendir(int *dirfd_p)
 #endif
 
 static int
-unix_scan_regular_file(const char *path, u64 size, struct wim_inode *inode,
+unix_scan_regular_file(const char *path, u64 blocks, u64 size,
+                      struct wim_inode *inode,
                       struct list_head *unhashed_blobs)
 {
        struct blob_descriptor *blob = NULL;
        struct wim_inode_stream *strm;
 
-       inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
+       /*
+        * Set FILE_ATTRIBUTE_SPARSE_FILE if the file uses less disk space than
+        * expected given its size.
+        */
+       if (blocks < DIV_ROUND_UP(size, 512))
+               inode->i_attributes = FILE_ATTRIBUTE_SPARSE_FILE;
+       else
+               inode->i_attributes = FILE_ATTRIBUTE_NORMAL;
 
        if (size) {
                blob = new_blob_descriptor();
@@ -437,8 +445,9 @@ unix_build_dentry_tree_recursive(struct wim_dentry **tree_ret,
        }
 
        if (S_ISREG(stbuf.st_mode)) {
-               ret = unix_scan_regular_file(full_path, stbuf.st_size,
-                                            inode, params->unhashed_blobs);
+               ret = unix_scan_regular_file(full_path, stbuf.st_blocks,
+                                            stbuf.st_size, inode,
+                                            params->unhashed_blobs);
        } else if (S_ISDIR(stbuf.st_mode)) {
                ret = unix_scan_directory(tree, full_path, full_path_len,
                                          dirfd, relpath, params);