Re: [PATCH RFC 00/17] ubifs: Add filesystem repair support

[Zhihao Cheng]

在 2024/1/3 11:18, Zhihao Cheng 写道:
> 在 2024/1/3 4:45, Richard Weinberger 写道:
> > ----- Ursprüngliche Mail -----
> > > Von: "chengzhihao1" <chengzhihao1@xxxxxxxxxx>
> > > I come up with another way to implement fsck.ubifs:
> > >
> > > There are three modes:
> > >
> > > 1. common mode(no options): Ask user whether to fix as long as a problem
> > > is detected.
> >
> > Makes sense.
> >
> > > 2. safe mode(-a option): Auto repair as long as no data/files lost(eg.
> > > nlink, isize, xattr_cnt, which can be corrected without dropping nodes),
> > > otherwise returns error code.
> >
> > Makes sense.
> > > 3. dangerous mode(-y option): Fix is always successful, unless
> > > superblock is corrupted. There are 2 situations:
> >
> > Please not use "-y". Usually "-y" stands for "answer yes to all 
> > questions".
> > But selecting names for command line flags is currently my least concern.
> > >    a) TNC is valid: fsck will print which file is dropped and which
> > > file's data is dropped
> >
> > Sounds also good.
> > >    b) TNC is invalid: fsck will scan all nodes without referencing TNC,
> > > same as this patchset does
> >
> > I'd make this a distinct mode.
> > It can be used to rebuild index and LEB property trees.
> > This is basically a "drop trees and rebuild" mode.
>
> OK, then fsck will have four modes.

How about merging 3(a) and 3(b) as one mode(dangerous mode)? If fsck can 
get a good TNC(all non-leaf index nodes are valid), fsck executes as 
3(a) describes. If fsck cannot find a good TNC, fsck executes as 3(b) 
and reminds user that "TNC is damaged, nodes dropping is not awared".