Re: [PATCH] hfsplus: don't oops on bad FS

[Colin Leroy <colin@colino.net>]

On Mon, 25 Apr 2005 22:26:26 +0200 (CEST)
Roman Zippel <zippel@linux-m68k.org> wrote:

Hi,

> > > Actually it looks like we are always leaking it, so actually 
> > > hfsplus_put_super() needs fixing, could you add the check and
> > > kfree there and do the same fix for hfs?
> > 
> > Mmh, right. Here's an updated version that fixes it too.
> 
> Don't change hfsplus_fill_super, add a "if (!sb->s_fs_info) return;"
> to hfsplus_put_super 

I don't get it. I do have to change hfsplus_fill_super to free 
sb->s_fs_info, don't I? If I just nullify it there, there will be a
leak, and if I don't, put_super won't know it shouldn't do anything.

This try brings in less changes, but I don't see how to do even less:
(pseudo-patch that won't apply, just to know):
--- fs/hfsplus/super.c.orig     2005-04-25 21:56:56.000000000 +0200
+++ fs/hfsplus/super.c  2005-04-26 08:57:22.000000000 +0200
@@ -207,6 +207,9 @@ static void hfsplus_write_super(struct s

 static void hfsplus_put_super(struct super_block *sb)
 {
+       if (!sb->s_fs_info)
+               return;
+
        dprint(DBG_SUPER, "hfsplus_put_super\n");
        if (!(sb->s_flags & MS_RDONLY)) {
                struct hfsplus_vh *vhdr = HFSPLUS_SB(sb).s_vhdr;
@@ -226,6 +229,9 @@ static void hfsplus_put_super(struct sup
        brelse(HFSPLUS_SB(sb).s_vhbh);
        if (HFSPLUS_SB(sb).nls)
                unload_nls(HFSPLUS_SB(sb).nls);
+
+       kfree(sb->s_fs_info);
+       sb->s_fs_info = NULL;
 }

 static int hfsplus_statfs(struct super_block *sb, struct kstatfs *buf)
@@ -427,6 +433,9 @@ out:
        return 0;

 cleanup:
+       kfree(sb->s_fs_info);
+       sb->s_fs_info = NULL;
+
        hfsplus_put_super(sb);
        if (nls)
                unload_nls(nls);

What do you think?

Thanks,
-- 
Colin