On Tue, Mar 18, 2025 at 03:41:08PM -0400, James Bottomley wrote:
> [Note this is built on top of the previous patch to populate path.mnt]
>
> This turned out to be much simpler than I feared. The first patch
> breaks out the core of the current dcache_readdir() into an internal
> function with a callback (there should be no functional change). The
> second adds a new API, simple_iterate_call(), which loops over the
> dentries in the next level and executes a callback for each one and
> the third which removes all the efivarfs superblock and mnt crud and
> replaces it with this simple callback interface. I think the
> diffstats of the third patch demonstrate how much nicer it is for us:
I suspect that you are making it too generic for its own good.
dcache_readdir() needs to cope with the situation when there are
fuckloads of opened-and-unliked files in there. That's why we
play those games with cursors under if (need_resched()) there.
That's not the case for efivarfs. There you really want just
"grab a reference to the next positive, drop the reference we
were given" and that's it.
IOW, find_next_child() instead of scan_positives(). Export that
and it becomes just a simple loop -
child = NULL;
while ((child = find_next_child(parent, child)) != NULL) {
struct inode *inode = d_inode(child);
struct efivar_entry *entry = efivar_entry(inode);
err = efivar_entry_size(entry, &size);
inode_lock(inode);
i_size_write(inode, err ? 0 : size + sizeof(__u32));
inode_unlock(inode);
if (err)
simple_recursive_removal(child, NULL);
}
and that's it. No callbacks, no cursors, no iterators - just an
export of helper already there.
