Gautham Ananthakrishna 6f1b228529 ocfs2: fix race between searching chunks and release journal_head from buffer_head
Encountered a race between ocfs2_test_bg_bit_allocatable() and
jbd2_journal_put_journal_head() resulting in the below vmcore.

  PID: 106879  TASK: ffff880244ba9c00  CPU: 2   COMMAND: "loop3"
  Call trace:
    panic
    oops_end
    no_context
    __bad_area_nosemaphore
    bad_area_nosemaphore
    __do_page_fault
    do_page_fault
    page_fault
      [exception RIP: ocfs2_block_group_find_clear_bits+316]
    ocfs2_block_group_find_clear_bits [ocfs2]
    ocfs2_cluster_group_search [ocfs2]
    ocfs2_search_chain [ocfs2]
    ocfs2_claim_suballoc_bits [ocfs2]
    __ocfs2_claim_clusters [ocfs2]
    ocfs2_claim_clusters [ocfs2]
    ocfs2_local_alloc_slide_window [ocfs2]
    ocfs2_reserve_local_alloc_bits [ocfs2]
    ocfs2_reserve_clusters_with_limit [ocfs2]
    ocfs2_reserve_clusters [ocfs2]
    ocfs2_lock_refcount_allocators [ocfs2]
    ocfs2_make_clusters_writable [ocfs2]
    ocfs2_replace_cow [ocfs2]
    ocfs2_refcount_cow [ocfs2]
    ocfs2_file_write_iter [ocfs2]
    lo_rw_aio
    loop_queue_work
    kthread_worker_fn
    kthread
    ret_from_fork

When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the
bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and
released the jounal head from the buffer head.  Needed to take bit lock
for the bit 'BH_JournalHead' to fix this race.

Link: https://lkml.kernel.org/r/1634820718-6043-1-git-send-email-gautham.ananthakrishna@oracle.com
Signed-off-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: <rajesh.sivaramasubramaniom@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-28 17:18:55 -07:00
..
2021-10-07 11:20:08 -07:00
2021-08-19 09:02:55 +09:00
2021-10-11 16:48:19 -07:00
2021-10-19 09:36:06 +02:00
2021-04-12 15:04:29 +02:00
2021-07-06 11:06:04 -07:00
2021-09-04 10:48:47 -07:00
2021-09-02 12:32:12 -07:00
2021-08-26 22:28:02 +02:00
2021-09-22 09:21:02 -07:00
2021-09-04 10:25:26 -07:00
2021-09-10 09:46:48 -07:00
2021-06-30 12:21:16 -07:00
2021-06-29 10:53:48 -07:00
2021-09-03 15:33:47 -07:00
2021-08-16 10:50:32 -06:00
2021-08-19 09:02:55 +09:00
2021-09-09 11:39:57 -07:00
\n
2021-08-30 10:24:50 -07:00
2021-08-31 11:13:35 -07:00
2021-09-09 13:25:49 -07:00
2021-09-11 14:48:42 -07:00
2021-10-19 17:09:34 -06:00
2021-08-31 11:06:32 -07:00
2021-06-29 10:53:48 -07:00
2021-08-18 22:08:24 +02:00
2021-08-10 17:57:22 +02:00