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

From: Chao Yu
Date: Mon Oct 16 2023 - 05:17:14 EST


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!