Messages in this thread | | | Date | Mon, 21 Feb 2011 11:47:09 +0100 | From | Jiri Slaby <> | Subject | Re: OOPS in configfs when doing d_delete |
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On 02/21/2011 11:44 AM, Joel Becker wrote: > On Mon, Feb 21, 2011 at 11:20:18AM +0100, Jiri Slaby wrote: >> when configfs_attach_group fails in configfs_register_subsystem: >> dentry = d_alloc(configfs_sb->s_root, &name); >> if (dentry) { >> d_add(dentry, NULL); >> >> err = configfs_attach_group(sd->s_element, &group->cg_item, >> dentry); >> if (err) { >> d_delete(dentry); >> dput(dentry); >> >> >> d_delete kills the kernel. I don't know what the actual bug is here, but >> d_delete looks broken anyway: >> spin_lock(&dentry->d_lock); >> inode = dentry->d_inode; >> isdir = S_ISDIR(inode->i_mode); <======== dereference >> if (dentry->d_count == 1) { >> if (inode && !spin_trylock(&inode->i_lock)) { >> ^^^^^ <============= test >> >> It seems like a superfluous test, not a potential null dereference to >> me, right? > > I think you're right about the superfluous test, but I need more > investigation to see what's going on. Thanks for the report. > What was causing attach_group() to fail? Do you know?
Dunno, I just modprobe'd the configfs example from Doc dir (configfs_example_macros).
regards, -- js suse labs
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