[PATCH v3 0/2] ext4, jbd2: journal cycled record transactions between each mount

[Zhang Yi <yi.zhang@huaweicloud.com>]

From: Zhang Yi <yi.zhang@huawei.com>

v3->v2:
 - Prevent warning if mount old image with journal_cycle_record enabled.
 - Limit this mount option into ext4 iamge only.
v1->v2:
 - Fix the format type warning.
 - Add more check of journal_cycle_record mount options in remount.

Hello!

This patch set is the third version of the journal_cycle_record mount
option. It save journal head for a clean unmounted file system in the
journal super block, which could let us record journal transactions
between each mount continuously. It could help us to do journal
backtrack and find root cause from a corrupted filesystem. Current
filesystem's corruption analysis is difficult and less useful
information, especially on the real products. It is useful to some
extent, especially for the cases of doing fuzzy tests and deploy in
some shout-runing products.

I have finished the corresponding e2fsprogs part and I will them send
out separately, all of these have done below test cases and also passed
xfstests in auto mode.
 - Mount a filesystem with empty journal.
 - Mount a filesystem with journal ended in an unrecovered complete
   transaction.
 - Mount a filesystem with journal ended in an incomplete transaction.
 - Mount a corrupted filesystem with out of bound journal s_head.
 - Mount old filesystem without journal s_head set.

Any comments are welcome.

Thanks!
Yi.

v2: https://lore.kernel.org/linux-ext4/20230202142224.3679549-1-yi.zhang@huawei.com/
v1: https://lore.kernel.org/linux-ext4/20230119034600.3431194-3-yi.zhang@huaweicloud.com/

Zhang Yi (2):
  jbd2: continue to record log between each mount
  ext4: add journal cycled recording support

 fs/ext4/ext4.h       |  2 ++
 fs/ext4/super.c      | 18 ++++++++++++++++++
 fs/jbd2/journal.c    | 18 ++++++++++++++++--
 fs/jbd2/recovery.c   | 22 +++++++++++++++++-----
 include/linux/jbd2.h |  9 +++++++--
 5 files changed, 60 insertions(+), 9 deletions(-)

-- 
2.31.1