Re: [RFC v2 0/5] md/raid1: introduce a new sync action to repair badblocks

[Zheng Qixing]

在 2026/2/4 0:31, Christoph Hellwig 写道:

> On Tue, Feb 03, 2026 at 04:08:23PM +0800, Zheng Qixing wrote:
> > Hi,
> >
> > 在 2026/2/3 15:31, Christoph Hellwig 写道:
> > > Just curious, but what kind of devices do you see that have
> > > permanent bad blocks at a fixed location that are not fixed by
> > > rewriting the sector?
> > The bad_blocks entries record sectors where I/O failed, which
> > indicates that the device-internal remapping did not succeed
> > at that time.
> >
> > `rectify` does not assume a permanently bad or fixed LBA. Its
> > purpose is to trigger an additional rewrite, giving the underlying
> > device (e.g. FTL or firmware) another opportunity to perform its
> > own remapping.
> Well, what devices do you see where writes fail, but rewrites
> fix them?

I understand your concerns, but I do not have a concrete example tied to a specific device model... The intent here is to provide an additional rewrite opportunity, which allows the write path to be exercised again and gives the underlying device or stack a chance to recover or remap the affected range. For remote storage devices, I/O may fail due to network or transport issues. If the final attempt fails, MD can record the affected range in bad_blocks. This behavior does not appear to be tied to a specific device model. For local storage, some controllers may have limitations or corner cases in their remapping mechanisms. In such cases, a sector that could potentially be recovered may be marked as bad, leaving no opportunity for a subsequent successful rewrite.