2024-03-17 22:15:57

by John Sperbeck

Subject: [PATCH] init: open /initrd.image with O_LARGEFILE

If initrd data is larger than 2Gb, we'll eventually fail to write to
the /initrd.image file when we hit that limit, unless O_LARGEFILE is set.

Signed-off-by: John Sperbeck <[email protected]>
---
init/initramfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index 76deb48c38cb..b607d3463b47 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -683,7 +683,7 @@ static void __init populate_initrd_image(char *err)

printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
err);
- file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700);
+ file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
if (IS_ERR(file))
return;

--
2.44.0.291.gc1ea87d7ee-goog

2024-03-17 23:47:55

by Randy Dunlap

Subject: Re: [PATCH] init: open /initrd.image with O_LARGEFILE

Hi,

On 3/17/24 15:15, John Sperbeck wrote:
> If initrd data is larger than 2Gb, we'll eventually fail to write to
> the /initrd.image file when we hit that limit, unless O_LARGEFILE is set.
>

Could this be related to
https://lore.kernel.org/lkml/CAHY78BqCpMQptPN0SMaXuRqHOhYi+wnMEUSTYt7OHDZih4e7yQ@mail.gmail.com/
?

Thanks.

> Signed-off-by: John Sperbeck <[email protected]>
> ---
> init/initramfs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/init/initramfs.c b/init/initramfs.c
> index 76deb48c38cb..b607d3463b47 100644
> --- a/init/initramfs.c
> +++ b/init/initramfs.c
> @@ -683,7 +683,7 @@ static void __init populate_initrd_image(char *err)
>
> printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
> err);
> - file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700);
> + file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
> if (IS_ERR(file))
> return;
>

--
#Randy

2024-03-18 19:02:30

by John Sperbeck

Subject: Re: [PATCH] init: open /initrd.image with O_LARGEFILE

On Sun, Mar 17, 2024 at 4:47 PM Randy Dunlap <[email protected]> wrote:
>
> Hi,
>
> On 3/17/24 15:15, John Sperbeck wrote:
> > If initrd data is larger than 2Gb, we'll eventually fail to write to
> > the /initrd.image file when we hit that limit, unless O_LARGEFILE is set.
> >
>
> Could this be related to
> https://lore.kernel.org/lkml/CAHY78BqCpMQptPN0SMaXuRqHOhYi+wnMEUSTYt7OHDZih4e7yQ@mail.gmail.com/
> ?
>
> Thanks.
>

I think there's a separate problem that this patch doesn't address.
If an individual component of a CPIO file is larger than 2Gb, then
there will be an EFBIG error when processing it. The backtrace where
this occurs would be:

generic_write_checks_count
generic_write_checks
generic_file_write_iter
__kernel_write_iter
kernel_write
xwrite
do_copy
unpack_to_rootfs
do_populate_rootfs
async_run_entry_fn
process_scheduled_works
worker_thread
kthread
ret_from_fork
ret_from_fork_asm

I think that could be dealt with by a patch to add O_LARGEFILE to
'openflags' in initramfs:do_name().