X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmodify.c;h=3e7e1c5684780f7fdf3a8a79c1f487bfae3bd73b;hp=b5342a2ffa9084b27e729cf1e533f1c2256474ff;hb=5046b052366414f09940041ad79244c320d24751;hpb=140c0920af14b19292e8b7694bb91864c8f52f3c

diff --git a/src/modify.c b/src/modify.c
index b5342a2f..3e7e1c56 100644
--- a/src/modify.c
+++ b/src/modify.c
@@ -44,7 +44,7 @@
  * the WIM image. */
 #define WIMLIB_ADD_IMAGE_FLAG_ROOT 0x80000000
 
-void destroy_image_metadata(struct image_metadata *imd,struct lookup_table *lt)
+void destroy_image_metadata(struct image_metadata *imd, struct lookup_table *lt)
 {
 	free_dentry_tree(imd->root_dentry, lt);
 	free_security_data(imd->security_data);
@@ -236,15 +236,50 @@ out:
 struct wim_pair {
 	WIMStruct *src_wim;
 	WIMStruct *dest_wim;
+	struct list_head lte_list_head;
 };
 
+static int allocate_lte_if_needed(struct dentry *dentry, void *arg)
+{
+	const WIMStruct *src_wim, *dest_wim;
+	struct list_head *lte_list_head;
+	struct inode *inode;
+
+	src_wim = ((struct wim_pair*)arg)->src_wim;
+	dest_wim = ((struct wim_pair*)arg)->dest_wim;
+	lte_list_head = &((struct wim_pair*)arg)->lte_list_head;
+	inode = dentry->d_inode;
+
+	wimlib_assert(!inode->resolved);
+
+	for (unsigned i = 0; i <= inode->num_ads; i++) {
+		struct lookup_table_entry *src_lte, *dest_lte;
+		src_lte = inode_stream_lte_unresolved(inode, i,
+						      src_wim->lookup_table);
+
+		if (src_lte && ++src_lte->out_refcnt == 1) {
+			dest_lte = inode_stream_lte_unresolved(inode, i,
+							       dest_wim->lookup_table);
+
+			if (!dest_lte) {
+				dest_lte = clone_lookup_table_entry(src_lte);
+				if (!dest_lte)
+					return WIMLIB_ERR_NOMEM;
+				list_add_tail(&dest_lte->list, lte_list_head);
+			}
+		}
+	}
+	return 0;
+}
+
 /* 
  * This function takes in a dentry that was previously located only in image(s)
- * in @src_wim, but now is being added to @dest_wim. If there is in fact already a
- * lookup table entry for this file in the lookup table of the destination WIM
- * file, we simply increment its reference count.  Otherwise, a new lookup table
- * entry is created that references the location of the file resource in the
- * source WIM file through the other_wim_fp field of the lookup table entry.
+ * in @src_wim, but now is being added to @dest_wim.  For each stream associated
+ * with the dentry, if there is already a lookup table entry for that stream in
+ * the lookup table of the destination WIM file, its reference count is
+ * incrementej.  Otherwise, a new lookup table entry is created that points back
+ * to the stream in the source WIM file (through the @hash field combined with
+ * the @wim field of the lookup table entry.)
  */
 static int add_lte_to_dest_wim(struct dentry *dentry, void *arg)
 {
@@ -261,19 +296,28 @@ static int add_lte_to_dest_wim(struct dentry *dentry, void *arg)
 		struct lookup_table_entry *src_lte, *dest_lte;
 		src_lte = inode_stream_lte_unresolved(inode, i,
 						      src_wim->lookup_table);
-		if (!src_lte)
+
+		if (!src_lte) /* Empty or nonexistent stream. */
 			continue;
+
 		dest_lte = inode_stream_lte_unresolved(inode, i,
 						       dest_wim->lookup_table);
 		if (dest_lte) {
 			dest_lte->refcnt++;
 		} else {
-			dest_lte = MALLOC(sizeof(struct lookup_table_entry));
-			if (!dest_lte)
-				return WIMLIB_ERR_NOMEM;
-			memcpy(dest_lte, src_lte, sizeof(struct lookup_table_entry));
+			struct list_head *lte_list_head;
+			struct list_head *next;
+
+			lte_list_head = &((struct wim_pair*)arg)->lte_list_head;
+			wimlib_assert(!list_empty(lte_list_head));
+
+			next = lte_list_head->next;
+			list_del(next);
+			dest_lte = container_of(next, struct lookup_table_entry, list);
 			dest_lte->part_number = 1;
 			dest_lte->refcnt = 1;
+			wimlib_assert(hashes_equal(dest_lte->hash, src_lte->hash));
+
 			lookup_table_insert(dest_wim->lookup_table, dest_lte);
 		}
 	}
@@ -287,6 +331,9 @@ static int add_lte_to_dest_wim(struct dentry *dentry, void *arg)
  *
  * Does not update the XML data.
  *
+ * On failure, WIMLIB_ERR_NOMEM is returned and no changes are made.  Otherwise,
+ * 0 is returned and the image metadata array of @w is modified.
+ *
  * @w:		  The WIMStruct for the WIM file.
  * @root_dentry:  The root of the directory tree for the image.
  * @sd:		  The security data for the image.
@@ -297,7 +344,9 @@ static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry,
 	struct lookup_table_entry *metadata_lte;
 	struct image_metadata *imd;
 	struct image_metadata *new_imd;
-	struct link_group_table *lgt;
+	int ret;
+
+	wimlib_assert(root_dentry != NULL);
 
 	DEBUG("Reallocating image metadata array for image_count = %u",
 	      w->hdr.image_count + 1);
@@ -330,8 +379,12 @@ static int add_new_dentry_tree(WIMStruct *w, struct dentry *root_dentry,
 	w->image_metadata	= imd;
 	w->hdr.image_count++;
 
-	/* Change the current image to the new one. */
-	return wimlib_select_image(w, w->hdr.image_count);
+	/* Change the current image to the new one.  There should not be any
+	 * ways for this to fail, since the image is valid and the dentry tree
+	 * is already in memory. */
+	ret = wimlib_select_image(w, w->hdr.image_count);
+	wimlib_assert(ret == 0);
+	return ret;
 out_free_metadata_lte:
 	FREE(metadata_lte);
 out_free_imd:
@@ -399,8 +452,7 @@ WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 					export_flags &= ~WIMLIB_EXPORT_FLAG_BOOT;
 
 				ret = wimlib_export_image(src_wim, i, dest_wim, 
-							  NULL,
-							  dest_description,
+							  NULL, NULL,
 							  export_flags,
 							  additional_swms,
 							  num_additional_swms);
@@ -419,6 +471,13 @@ WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 		      dest_name, src_image);
 	}
 
+	if (!dest_description) {
+		dest_description = wimlib_get_image_description(src_wim,
+								src_image);
+		DEBUG("Using description `%s' for source image %d",
+		      dest_description, src_image);
+	}
+
 	DEBUG("Exporting image %d from `%s'", src_image, src_wim->filename);
 
 	if (wimlib_image_name_in_use(dest_wim, dest_name)) {
@@ -448,32 +507,56 @@ WIMLIBAPI int wimlib_export_image(WIMStruct *src_wim,
 		goto out;
 	}
 
-	/* Cleaning up here on failure would be hard.  For example, we could
-	 * fail to allocate memory in add_lte_to_dest_wim(),
-	 * leaving the lookup table entries in the destination WIM in an
-	 * inconsistent state.  Until these issues can be resolved,
-	 * wimlib_export_image() is documented as leaving dest_wim in an
-	 * indeterminate state.  */
-	root = wim_root_dentry(src_wim);
-	sd = wim_security_data(src_wim);
-	for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
+	/* Pre-allocate the new lookup table entries that will be needed.  This
+	 * way, it's not possible to run out of memory part-way through
+	 * modifying the lookup table of the destination WIM. */
 	wims.src_wim = src_wim;
 	wims.dest_wim = dest_wim;
-	ret = for_dentry_in_tree(root, add_lte_to_dest_wim, &wims);
+	INIT_LIST_HEAD(&wims.lte_list_head);
+	for_lookup_table_entry(src_wim->lookup_table, lte_zero_out_refcnt, NULL);
+	root = wim_root_dentry(src_wim);
+	for_dentry_in_tree(root, dentry_unresolve_ltes, NULL);
+	ret = for_dentry_in_tree(root, allocate_lte_if_needed, &wims);
 	if (ret != 0)
-		goto out;
+		goto out_free_ltes;
+
+	ret = xml_export_image(src_wim->wim_info, src_image,
+			       &dest_wim->wim_info, dest_name, dest_description);
+	if (ret != 0)
+		goto out_free_ltes;
+
+	sd = wim_security_data(src_wim);
 	ret = add_new_dentry_tree(dest_wim, root, sd);
 	if (ret != 0)
-		goto out;
+		goto out_xml_delete_image;
+
+
+	/* All memory allocations have been taken care of, so it's no longer
+	 * possible for this function to fail.  Go ahead and increment the
+	 * reference counts of the dentry tree and security data, then update
+	 * the lookup table of the destination WIM and the boot index, if
+	 * needed. */
+	for_dentry_in_tree(root, increment_dentry_refcnt, NULL);
 	sd->refcnt++;
+	for_dentry_in_tree(root, add_lte_to_dest_wim, &wims);
+	wimlib_assert(list_empty(&wims.lte_list_head));
 
 	if (flags & WIMLIB_EXPORT_FLAG_BOOT) {
 		DEBUG("Setting boot_idx to %d", dest_wim->hdr.image_count);
 		dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 	}
+	ret = 0;
+	goto out;
+
+out_xml_delete_image:
+	xml_delete_image(&dest_wim->wim_info, dest_wim->hdr.image_count);
+out_free_ltes:
+	{
+		struct lookup_table_entry *lte, *tmp;
+		list_for_each_entry_safe(lte, tmp, &wims.lte_list_head, list)
+			free_lookup_table_entry(lte);
+	}
 
-	ret = xml_export_image(src_wim->wim_info, src_image, &dest_wim->wim_info,
-			       dest_name, dest_description);
 out:
 	if (num_additional_swms) {
 		free_lookup_table(src_wim->lookup_table);
@@ -891,7 +974,7 @@ int do_add_image(WIMStruct *w, const char *dir, const char *name,
 	if (flags & WIMLIB_ADD_IMAGE_FLAG_BOOT)
 		wimlib_set_boot_idx(w, w->hdr.image_count);
 
-	ret = xml_add_image(w, root_dentry, name);
+	ret = xml_add_image(w, name);
 	if (ret != 0)
 		goto out_destroy_imd;