android_kernel_google_msm/fs/jbd2
Daeho Jeong 8fb4b054c9 ext4, jbd2: ensure entering into panic after recording an error in superblock
commit 4327ba52afd03fc4b5afa0ee1d774c9c5b0e85c5 upstream.

If a EXT4 filesystem utilizes JBD2 journaling and an error occurs, the
journaling will be aborted first and the error number will be recorded
into JBD2 superblock and, finally, the system will enter into the
panic state in "errors=panic" option.  But, in the rare case, this
sequence is little twisted like the below figure and it will happen
that the system enters into panic state, which means the system reset
in mobile environment, before completion of recording an error in the
journal superblock. In this case, e2fsck cannot recognize that the
filesystem failure occurred in the previous run and the corruption
wouldn't be fixed.

Task A                        Task B
ext4_handle_error()
-> jbd2_journal_abort()
  -> __journal_abort_soft()
    -> __jbd2_journal_abort_hard()
    | -> journal->j_flags |= JBD2_ABORT;
    |
    |                         __ext4_abort()
    |                         -> jbd2_journal_abort()
    |                         | -> __journal_abort_soft()
    |                         |   -> if (journal->j_flags & JBD2_ABORT)
    |                         |           return;
    |                         -> panic()
    |
    -> jbd2_journal_update_sb_errno()

Tested-by: Hobin Woo <hobin.woo@samsung.com>
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Zefan Li <lizefan@huawei.com>
2016-10-26 23:15:25 +08:00
..
checkpoint.c jbd2: avoid infinite loop when destroying aborted journal 2015-10-22 09:20:08 +08:00
commit.c jbd2: avoid infinite loop when destroying aborted journal 2015-10-22 09:20:08 +08:00
journal.c ext4, jbd2: ensure entering into panic after recording an error in superblock 2016-10-26 23:15:25 +08:00
Kconfig
Makefile
recovery.c jbd2: issue cache flush after checkpointing even with internal journal 2012-03-13 22:22:54 -04:00
revoke.c jbd2: use KMEM_CACHE instead of kmem_cache_create() 2012-02-20 17:53:03 -05:00
transaction.c jbd2: don't BUG but return ENOSPC if a handle runs out of space 2014-01-08 09:42:12 -08:00