On Wed, 2005-03-30 at 12:39 -0800, Andrew Morton wrote: > Russ Weight <[EMAIL PROTECTED]> wrote: > > > > This patch sets the MS_ACTIVE bit in isofs_fill_super() prior to calling > > iget() or iput(). This eliminates a race condition between mount > > (for isofs) and kswapd that results in a system panic. > > > > Signed-off-by: Russ Weight <[EMAIL PROTECTED]> > > > > --- linux-2.6.12-rc1/fs/isofs/inode.c 2005-03-17 17:34:36.000000000 > > -0800 > > +++ linux-2.6.12-rc1-isofsfix/fs/isofs/inode.c 2005-03-22 > > 15:29:51.945607217 -0800 > > @@ -820,6 +820,7 @@ > > * the s_rock flag. Once we have the final s_rock value, > > * we then decide whether to use the Joliet descriptor. > > */ > > + s->s_flags |= MS_ACTIVE; > > inode = isofs_iget(s, sbi->s_firstdatazone, 0); > > > > /* > > @@ -909,6 +910,7 @@ > > kfree(opt.iocharset); > > kfree(sbi); > > s->s_fs_info = NULL; > > + s->s_flags &= ~MS_ACTIVE; > > return -EINVAL; > > } > > > > The patch is obviously safe enough, but seems a bit kludgy. > > The basic problem here appears to be that isofs is doing iget/iput in > ->fill_super before MS_ACTIVE is set and the inode freeing code > (generic_forget_inode) doesn't expect that to happen, yes?
Yes. > I wonder if it would make more sense for all the ->fill_super callers to > set MS_ACTIVE prior to calling ->fill_super(), and clear MS_ACTIVE if > fill_super() failed? It does seem a bit kludgy. I was trying keep the changes in isofs specific code, and this seemed the best way to do it. When you say "all the ->fill_super callers", are you referring to the fill_super functions for all filesystems? Or just callers to isofs_fill_super()? isofs_fill_super() is called by get_sb_bdev(), which is in the generic filesystem code. get_sb_bdev() receives a pointer as a parameter when it is called from isofs_get_sb(). To make a change in get_sb_bdev() would be to affect many (all?) filesystems. This may be the right thing to do - although it seems a little heavy-weight since the failure hasn't been reported in other filesystems. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
