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

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Message-ID: <aQCPQ1V8DuAMpmVc@li-dc0c254c-257c-11b2-a85c-98b6c1322444.ibm.com>
Date: Tue, 28 Oct 2025 15:09:15 +0530
From: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
To: Baokun Li <libaokun1@...wei.com>
Cc: Zorro Lang <zlang@...hat.com>, fstests@...r.kernel.org,
        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 Tue, Oct 28, 2025 at 03:57:00PM +0800, Baokun Li wrote:
> 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>

Hi Baokun, I was planning to CC you since I thought you might've hit it,
but missed it while sending the mail.

Thanks for the review :)

Regards,
ojaswin

> 
> >  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
> 
>