[U-Boot] [PATCH 1/2] ext4: Avoid corruption of directories with hash tree indexes

[Stefan Brüns]

While directories can be read using the old linear scan method, adding a
new file would require updating the index tree (alternatively, the whole
tree could be removed).

Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>
---
 fs/ext4/ext4_write.c | 5 +++++
 include/ext4fs.h     | 1 +
 2 files changed, 6 insertions(+)

diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 4235b95..ccc8a9c 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -864,6 +864,11 @@ int ext4fs_write(const char *fname, unsigned char *buffer,
 		goto fail;
 	if (ext4fs_iget(parent_inodeno, g_parent_inode))
 		goto fail;
+	/* do not mess up a directory using hash trees */
+	if (le32_to_cpu(g_parent_inode->flags) & EXT4_INDEX_FL) {
+		printf("hash tree directory\n");
+		goto fail;
+	}
 	/* check if the filename is already present in root */
 	existing_file_inodeno = ext4fs_filename_unlink(filename);
 	if (existing_file_inodeno != -1) {
diff --git a/include/ext4fs.h b/include/ext4fs.h
index e3f6216..6e31c73 100644
--- a/include/ext4fs.h
+++ b/include/ext4fs.h
@@ -28,6 +28,7 @@
 #define __EXT4__
 #include <ext_common.h>
 
+#define EXT4_INDEX_FL		0x00001000 /* Inode uses hash tree index */
 #define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
 #define EXT4_EXT_MAGIC			0xf30a
 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM	0x0010
-- 
2.9.2