Re: [PATCH 1/1] initrd: use O_SYNC flag while opening /dev/ram for write

[Christoph Hellwig]

On Mon, Jul 08, 2024 at 11:09:23PM +0300, George Stark wrote:
> initrd image is written to the /dev/ram block device using filp_open(),
> kernel_write()

First question: why are you using the legacy initrd and not initramfs?

> . After fput() /dev/ram is mounted and may fail due to not
> all data is actually written to the device yet. The mount error remains
> hidden due to MS_SILENT flag usage and mount_root_generic has retries.
> So use O_SYNC flag to have all data written to /dev/ram before mounting.

O_SYNC is highly inefficient.  If you have a valid reason to care about
a corner case in the hopefully soon to be remvoved legacy initrd code,
the right way to do this is a single fdatasync after the writes have
finished.