[PATCH 04/11] fs: free inodes we no longer need

[Sascha Hauer]

Hi Ahmad,

On Tue, Aug 04, 2020 at 12:02:37AM +0200, Ahmad Fatoum wrote:
> Hello Sascha,
> 
> On 6/15/20 8:02 AM, Sascha Hauer wrote:
> > So far we freed the no longer needed inodes only at unmount time.
> > Let's trust our reference counting a bit more and free them once
> > the reference counter hits zero.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> > ---
> >  fs/fs.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fs/fs.c b/fs/fs.c
> > index cecb3d70e0..e04cadfe5d 100644
> > --- a/fs/fs.c
> > +++ b/fs/fs.c
> > @@ -1090,10 +1090,12 @@ void iput(struct inode *inode)
> >  	if (!inode)
> >  		return;
> >  
> > -	if (!inode->i_count)
> > -		return;
> > -
> >  	inode->i_count--;
> > +
> > +	if (!inode->i_count) {
> > +		list_del(&inode->i_sb_list);
> 
> There is no explicit initialization of i_sb_list anywhere, only
> list_add.
> 
> Without reverting this patch, I can reproduce null pointer dereference
> booting from squashfs as i_sb_list remained uninitialized when this
> line is executed.
> 
> Can you drop this patch for now?

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Sascha

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