[U-Boot] [PATCH 2/3] test/fs: Check ext4 behaviour if dirent is first entry in directory block

[Stephen Warren]

On 09/11/2016 02:46 PM, Stefan Brüns wrote:
> This is a regression test for a crash happening if the first dirent
> in the block matches. Code tried to access a predecessor entry which
> does not exist.
> The crash happened for any block, but "." is always the first entry in
> the first directory block and thus easy to check for.

> diff --git a/test/fs/fs-test.sh b/test/fs/fs-test.sh

> +# Next test case checks writing a file whose dirent
> +# is the first in the block, which is always true for "."
> +# The write should fail, but the lookup should work
> +# Test Case 12 - Check directory traversal
> +${PREFIX}${WRITE} host${SUFFIX} $addr ${FPATH}. 0x10

Doesn't that attempt to write a file named ".", which would end up 
over-writing the directory content? Unless I'm misunderstanding, that 
doesn't seem like a good idea.

Also, ${FPATH} might be "", "/", "something", or "something/". Appending 
"." to some of those won't work the same way as some others.

> @@ -471,6 +477,11 @@ function check_results() {

> +	# Check lookup of 'dot' directory
> +	grep -A5 "Test Case 12 " "$1" | \
> +		egrep -q 'Unable to write file'
> +	pass_fail "TC12: 1MB write to . - write denied"

Oh, I see; this expects the write to be denied since the destination is 
a directory. Perhaps that's OK. I'd rather see a read attempt though, to 
guarantee that even if the access does end up being allowed, the FS 
isn't trashed for any future tests that may be added afterwards.