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

[Lukasz Majewski]

Hi Stefan,

> 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

Reviewed-by: Lukasz Majewski <l.majewski at samsung.com>

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group