Also, a tiny nit -- "fwupd" is the program that actually deploys the capsule updates -- the "LVFS" is just the webservice that vendors upload firmware to. Thanks.
Richard.
On Thursday, 27 February 2025 at 07:54, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
>
> On Wed, 26 Feb 2025 at 22:48, James Bottomley
> James.Bottomley@xxxxxxxxxxxxxxxxxxxxx wrote:
>
> > Temporarily allow the creation of zero length files in efivarfs so the
> > Linux Vendor Firmware Service can continue to operate. This hack should
> > be reverted as soon as the LVFS mechanisms for updating firmware have
> > been fixed.
> >
> > LVFS has been coded to open a firmware file, close it, remove the
> > immutable bit and write to it. Since commit 908af31f4896 ("efivarfs:
> > fix error on write to new variable leaving remnants") this behaviour
> > results in the first close removing the file which causes the second
> > write to fail. To allow LVFS to keep working code up an indicator of
> > size 1 if a write fails and only remove the file on that condition (so
> > create at zero size is allowed).
> >
> > Tested-by: Richard Hughes richard@xxxxxxxxxxx
> > Signed-off-by: James Bottomley James.Bottomley@xxxxxxxxxxxxxxxxxxxxx
> > ---
> > This should be reverted in the 6.15 release
>
>
> Thanks James. Mind resending this with a MUA that doesn't mangle patches?
>
> > fs/efivarfs/file.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
> > index cb1b6d0c3454..c294a8fc566d 100644
> > --- a/fs/efivarfs/file.c
> > +++ b/fs/efivarfs/file.c
> > @@ -57,10 +57,11 @@ static ssize_t efivarfs_file_write(struct file
> > *file,
> >
> > if (bytes == -ENOENT) {
> > /*
> > - * zero size signals to release that the write deleted
> > - * the variable
> > + * FIXME: temporary workaround for fwupdate, signal
> > + * failed write with a 1 to keep created but not
> > + * written files
> > */
> > - i_size_write(inode, 0);
> > + i_size_write(inode, 1);
> > } else {
> > i_size_write(inode, datasize + sizeof(attributes));
> > inode_set_mtime_to_ts(inode,
> > inode_set_ctime_current(inode));
> > @@ -124,7 +125,8 @@ static int efivarfs_file_release(struct inode
> > *inode, struct file *file)
> > struct efivar_entry *var = inode->i_private;
> >
> > inode_lock(inode);
> > - var->removed = (--var->open_count == 0 && i_size_read(inode)
> > == 0);
> > + /* FIXME: temporary work around for fwupdate */
> > + var->removed = (--var->open_count == 0 && i_size_read(inode)
> > == 1);
> > inode_unlock(inode);
> >
> > if (var->removed)
> > --
> > 2.43.0
