Messages in this thread | | | Date | Fri, 30 Jul 2021 15:18:57 -0700 | From | Jaegeuk Kim <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: reset free segment to prefree status when do_checkpoint() fail |
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On 07/20, Chao Yu wrote: > On 2021/7/20 2:25, Jaegeuk Kim wrote: > > On 07/19, Chao Yu wrote: > > > On 2021/4/27 20:37, Chao Yu wrote: > > > > I think just reverting dirty/free bitmap is not enough if checkpoint fails, > > > > due to we have updated sbi->cur_cp_pack and nat/sit bitmap, next CP tries > > > > to overwrite last valid meta/node/data, then filesystem will be corrupted. > > > > > > > > So I suggest to set cp_error if do_checkpoint() fails until we can handle > > > > all cases, which is not so easy. > > > > > > > > How do you think? > > > > > > Let's add below patch first before you figure out the patch which covers all > > > things. > > > > > > From 3af957c98e9e04259f8bb93ca0b74ba164f3f27e Mon Sep 17 00:00:00 2001 > > > From: Chao Yu <chao@kernel.org> > > > Date: Mon, 19 Jul 2021 16:37:44 +0800 > > > Subject: [PATCH] f2fs: fix to stop filesystem update once CP failed > > > > > > During f2fs_write_checkpoint(), once we failed in > > > f2fs_flush_nat_entries() or do_checkpoint(), metadata of filesystem > > > such as prefree bitmap, nat/sit version bitmap won't be recovered, > > > it may cause f2fs image to be inconsistent, let's just set CP error > > > flag to avoid further updates until we figure out a scheme to rollback > > > all metadatas in such condition. > > > > > > Reported-by: Yangtao Li <frank.li@vivo.com> > > > Signed-off-by: Yangtao Li <frank.li@vivo.com> > > > Signed-off-by: Chao Yu <chao@kernel.org> > > > --- > > > fs/f2fs/checkpoint.c | 10 +++++++--- > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > > index 6c208108d69c..096c85022f62 100644 > > > --- a/fs/f2fs/checkpoint.c > > > +++ b/fs/f2fs/checkpoint.c > > > @@ -1639,8 +1639,10 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > > > > > /* write cached NAT/SIT entries to NAT/SIT area */ > > > err = f2fs_flush_nat_entries(sbi, cpc); > > > - if (err) > > > + if (err) { > > > + f2fs_stop_checkpoint(sbi, false); > > > > I think we should abuse this, since we can get any known ENOMEM as well. > > Yup, but one critical issue here is it can break A/B update of NAT area, > so, in order to fix this hole, how about using NOFAIL memory allocation > in f2fs_flush_nat_entries() first until we figure out the finial scheme?
NOFAIL is risky, so how about adding a retry logic on ENOMEM with a message and then giving up if we can't get the memory? BTW, what about EIO or other family?
> > Thanks, > > > > > > goto stop; > > > + } > > > > > > f2fs_flush_sit_entries(sbi, cpc); > > > > > > @@ -1648,10 +1650,12 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > > f2fs_save_inmem_curseg(sbi); > > > > > > err = do_checkpoint(sbi, cpc); > > > - if (err) > > > + if (err) { > > > + f2fs_stop_checkpoint(sbi, false); > > > f2fs_release_discard_addrs(sbi); > > > - else > > > + } else { > > > f2fs_clear_prefree_segments(sbi, cpc); > > > + } > > > > > > f2fs_restore_inmem_curseg(sbi); > > > stop: > > > -- > > > 2.22.1
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