linux-ext4 - Re: [PATCH] ext4/048: Fix hangup due to no free inodes

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Message-ID: <89dbd368-4e76-45b5-8c82-9102db9f302e@huawei.com>
Date: Tue, 28 Oct 2025 15:57:00 +0800
From: Baokun Li <libaokun1@...wei.com>
To: Ojaswin Mujoo <ojaswin@...ux.ibm.com>, Zorro Lang <zlang@...hat.com>,
	<fstests@...r.kernel.org>
CC: Leah Rumancik <lrumancik@...gle.com>, <linux-ext4@...r.kernel.org>, Yang
 Erkun <yangerkun@...wei.com>
Subject: Re: [PATCH] ext4/048: Fix hangup due to no free inodes

On 2025-10-28 15:17, Ojaswin Mujoo wrote:
> We currently mkfs a 128MB filesystem, which gives use ~2048 free inodes
> on 64k blocksize. The test then keeps adding new files to a directory to
> trigger an htree split. For 64k this takes more than the total free
> inodes, which causes touch to return -ENOSPC. This leads to the while
> loop in induce_node_split() to never finish.
>
> To fix this:
> 1. Format a 1G FS which gives us atleast 16K inodes to work with.
> 2. _fail if there's any error while trying to induce node split, so we
>    dont get stuck in loop
>
> Fixes: 466ddbfd1151 ("ext4: add test for ext4_dir_entry2 wipe")
> Signed-off-by: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
> ---

Yeah, I also hit this issue when testing LBS — file creation kept failing
without breaking out of the loop, which resulted in the test case spinning
endlessly.

Looks good to me. Feel free to add:

Reviewed-by: Baokun Li <libaokun1@...wei.com>

>  tests/ext4/048 | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tests/ext4/048 b/tests/ext4/048
> index 2031c8c8..6343ff3a 100755
> --- a/tests/ext4/048
> +++ b/tests/ext4/048
> @@ -69,6 +69,11 @@ induce_node_split() {
>  	while [[ "$(stat --printf="%s" $testdir)" == "$dir_size" ]]; do
>  		file_num=$(($file_num + 1))
>  		touch $testdir/test"$(printf "%04d" $file_num)"
> +		local ret=$?
> +		if [[ $ret -ne 0 ]]
> +		then
> +			_fail "ERROR induce_node_split(): $ret"
> +		fi
>  	done
>  	_scratch_unmount >> $seqres.full 2>&1
>  }
> @@ -81,7 +86,7 @@ test_file1="test0001"
>  test_file2="test0002"
>  test_file3="test0003"
>  
> -_scratch_mkfs_sized $((128 * 1024 * 1024)) >> $seqres.full 2>&1
> +_scratch_mkfs_sized $((1 * 1024 * 1024 * 1024)) >> $seqres.full 2>&1
>  
>  # create scratch dir for testing
>  # create some files with no name a substr of another name so we can grep later