Re: [PATCH] f2fs: fix error path of __f2fs_build_free_nids

[Chao Yu]

On 2023/10/16 17:02, Zhiguo Niu wrote:
> Dear Chao,
>
> On Mon, Oct 16, 2023 at 3:37 PM Chao Yu <chao@xxxxxxxxxx> wrote:
> > On 2023/10/13 18:58, Zhiguo Niu wrote:
> > > SBI_NEED_FSCK should be set for fsck has a chance to
> > > repair in case of scan_nat_page fail in run time.
> > >
> > > Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> >
> > Hi Zhiguo,
> >
> > Can you please check below update?
> >
> >   From 9a3459d2d62a12f8708d72aa7808a1def9f9d92f Mon Sep 17 00:00:00 2001
> > From: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> > Date: Fri, 13 Oct 2023 18:58:23 +0800
> > Subject: [PATCH] f2fs: fix error path of __f2fs_build_free_nids
> >
> > If NAT is corrupted, let scan_nat_page() return EFSCORRUPTED, so that,
> > caller can set SBI_NEED_FSCK flag into checkpoint for later repair by
> > fsck.
> >
> > Also, this patch introduces a new fscorrupted error flag, and in above
> > scenario, it will persist the error flag into superblock synchronously
> > to avoid it has no luck to trigger a checkpoint to record SBI_NEED_FSCK.

Zhiguo,

If you have no more comments, I guess you can resend this one as v2.

Thanks,

> > Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
> > Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
> > ---
> >    fs/f2fs/node.c          | 11 +++++++++--
> >    include/linux/f2fs_fs.h |  1 +
> >    2 files changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index a2b2c6c7f66d..57d9dd3a43bc 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -2389,7 +2389,7 @@ static int scan_nat_page(struct f2fs_sb_info *sbi,
> >                  blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
> >
> >                  if (blk_addr == NEW_ADDR)
> > -                       return -EINVAL;
> > +                       return -EFSCORRUPTED;
> >
> >                  if (blk_addr == NULL_ADDR) {
> >                          add_free_nid(sbi, start_nid, true, true);
> > @@ -2504,7 +2504,14 @@ static int __f2fs_build_free_nids(struct f2fs_sb_info *sbi,
> >
> >                          if (ret) {
> >                                  f2fs_up_read(&nm_i->nat_tree_lock);
> > -                               f2fs_err(sbi, "NAT is corrupt, run fsck to fix it");
> > +
> > +                               if (ret == -EFSCORRUPTED) {
> > +                                       f2fs_err(sbi, "NAT is corrupt, run fsck to fix it");
> > +                                       set_sbi_flag(sbi, SBI_NEED_FSCK);
> > +                                       f2fs_handle_error(sbi,
> > +                                                       ERROR_INCONSISTENT_NAT);
> > +                               }
> > +
> >                                  return ret;
> >                          }
> >                  }
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 07ed69c2840d..039fe0ce8d83 100644
> > --- a/include/linux/f2fs_fs.h
> > +++ b/include/linux/f2fs_fs.h
> > @@ -104,6 +104,7 @@ enum f2fs_error {
> >          ERROR_CORRUPTED_VERITY_XATTR,
> >          ERROR_CORRUPTED_XATTR,
> >          ERROR_INVALID_NODE_REFERENCE,
> > +       ERROR_INCONSISTENT_NAT,
> >          ERROR_MAX,
> >    };
> >
> > --
> > 2.40.1
>
> Thank you for your updates and these updates are more reasonable based
> on the latest code.
> In addition,  I also modified the following code after I checked the
> related flow of f2fs_handle_error.
> ERROR_INCONSISTENT_FOOTER is reused here,   any suggestions for this?
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index d9e6087..94f5c7f 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1467,6 +1467,7 @@ static struct page *__get_node_page(struct
> f2fs_sb_info *sbi, pgoff_t nid,
>                            ofs_of_node(page), cpver_of_node(page),
>                            next_blkaddr_of_node(page));
>          set_sbi_flag(sbi, SBI_NEED_FSCK);
> +       f2fs_handle_error(sbi, ERROR_INCONSISTENT_FOOTER);
>          err = -EINVAL;
>   out_err:
>          ClearPageUptodate(page);
>
> If you have no other suggestions, I will update the "PATCH V2"
> Thanks!