ntfs-3g_apply.c: handle ntfs_attr_pwrite() short writes

[wimlib] / src / ntfs-3g_apply.c

diff --git a/src/ntfs-3g_apply.c b/src/ntfs-3g_apply.c
index 07dbdf65094df0e05c865b202b455b5b2f3e18d0..d0f3bb6cc86b0b850e43e7547cf5e2fb936824ed 100644 (file)
--- a/src/ntfs-3g_apply.c
+++ b/src/ntfs-3g_apply.c
@@ -517,7 +517,11 @@ ntfs_3g_create_directories(struct wim_dentry *root,
 
        root->d_inode->i_mft_no = FILE_root;
 
-       ret = ntfs_3g_create_dirs_recursive(root_ni, root, ctx);
+       ret = ntfs_3g_set_metadata(root_ni, root->d_inode, ctx);
+       if (!ret)
+               ret = ntfs_3g_create_empty_attributes(root_ni, root->d_inode, ctx);
+       if (!ret)
+               ret = ntfs_3g_create_dirs_recursive(root_ni, root, ctx);
 
        if (ntfs_inode_close(root_ni) && !ret) {
                ERROR_WITH_ERRNO("Error closing root of NTFS volume");
@@ -714,6 +718,7 @@ ntfs_3g_begin_extract_blob_instance(struct blob_descriptor *blob,
                                    struct ntfs_3g_apply_ctx *ctx)
 {
        struct wim_dentry *one_dentry = inode_first_extraction_dentry(inode);
+       ntfschar *stream_name;
        size_t stream_name_nchars;
        ntfs_attr *attr;
 
@@ -736,22 +741,29 @@ ntfs_3g_begin_extract_blob_instance(struct blob_descriptor *blob,
        /* It's a data stream (may be unnamed or named).  */
        wimlib_assert(strm->stream_type == STREAM_TYPE_DATA);
 
-       stream_name_nchars = utf16le_len_chars(strm->stream_name);
+       if (unlikely(stream_is_named(strm))) {
+               stream_name = strm->stream_name;
+               stream_name_nchars = utf16le_len_chars(stream_name);
 
-       if (stream_name_nchars &&
-           (ntfs_attr_add(ni, AT_DATA, strm->stream_name,
-                          stream_name_nchars, NULL, 0)))
-       {
-               ERROR_WITH_ERRNO("Failed to create named data stream of \"%s\"",
-                                dentry_full_path(one_dentry));
-               return WIMLIB_ERR_NTFS_3G;
+               if (ntfs_attr_add(ni, AT_DATA, stream_name,
+                                 stream_name_nchars, NULL, 0))
+               {
+                       ERROR_WITH_ERRNO("Failed to create named data stream of \"%s\"",
+                                        dentry_full_path(one_dentry));
+                       return WIMLIB_ERR_NTFS_3G;
+               }
+       } else {
+               /* Don't pass an empty string other than AT_UNNAMED to
+                * ntfs_attr_open() --- it violates assumptions made by
+                * libntfs-3g.  */
+               stream_name = AT_UNNAMED;
+               stream_name_nchars = 0;
        }
 
        /* This should be ensured by extract_blob_list()  */
        wimlib_assert(ctx->num_open_attrs < MAX_OPEN_FILES);
 
-       attr = ntfs_attr_open(ni, AT_DATA, strm->stream_name,
-                             stream_name_nchars);
+       attr = ntfs_attr_open(ni, AT_DATA, stream_name, stream_name_nchars);
        if (!attr) {
                ERROR_WITH_ERRNO("Failed to open data stream of \"%s\"",
                                 dentry_full_path(one_dentry));
@@ -843,16 +855,35 @@ out:
        return ret;
 }
 
+/* Note: contrary to its documentation, ntfs_attr_pwrite() can return a short
+ * count in non-error cases --- specifically, when writing to a compressed
+ * attribute and the requested count exceeds the size of an NTFS "compression
+ * block".  Therefore, we must continue calling ntfs_attr_pwrite() until all
+ * bytes have been written or a real error has occurred.  */
+static bool
+ntfs_3g_full_pwrite(ntfs_attr *na, u64 offset, size_t size, const u8 *data)
+{
+       while (size) {
+               s64 res = ntfs_attr_pwrite(na, offset, size, data);
+               if (unlikely(res <= 0))
+                       return false;
+               wimlib_assert(res <= size);
+               offset += res;
+               size -= res;
+               data += res;
+       }
+       return true;
+}
+
 static int
 ntfs_3g_extract_chunk(const void *chunk, size_t size, void *_ctx)
 {
        struct ntfs_3g_apply_ctx *ctx = _ctx;
-       s64 res;
 
        for (unsigned i = 0; i < ctx->num_open_attrs; i++) {
-               res = ntfs_attr_pwrite(ctx->open_attrs[i],
-                                      ctx->offset, size, chunk);
-               if (res != size) {
+               if (!ntfs_3g_full_pwrite(ctx->open_attrs[i],
+                                        ctx->offset, size, chunk))
+               {
                        ERROR_WITH_ERRNO("Error writing data to NTFS volume");
                        return WIMLIB_ERR_NTFS_3G;
                }