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[U-Boot,v5,05/16] ext4: Avoid corruption of directories with hash tree indexes

Message ID 2030abe11971426bbf3e949ce299f14e@rwthex-w2-b.rwth-ad.de
State Accepted
Delegated to: Tom Rini
Headers show

Commit Message

Stefan Brüns Sept. 6, 2016, 2:36 a.m. UTC 
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@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
---
 fs/ext4/ext4_write.c | 5 +++++
 include/ext4fs.h     | 1 +
 2 files changed, 6 insertions(+)

Comments

Tom Rini Sept. 23, 2016, 7:57 p.m. UTC | #1 
On Tue, Sep 06, 2016 at 04:36:45AM +0200, Stefan Brüns wrote:

> 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@rwth-aachen.de>
> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>

Applied to u-boot/master, thanks!
diff mbox

Patch

diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 42abd8d..50c8415 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -881,6 +881,11 @@  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