diff options
| author | Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com> | 2021-10-28 23:36:17 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-10-29 02:18:55 +0200 |
| commit | 6f1b228529ae49b0f85ab89bcdb6c365df401558 (patch) | |
| tree | be97c1c478b9c8afff8275aef0dbccb82fc69a72 /fs/ocfs2/suballoc.c | |
| parent | mm/oom_kill.c: prevent a race between process_mrelease and exit_mmap (diff) | |
| download | linux-6f1b228529ae49b0f85ab89bcdb6c365df401558.tar.xz linux-6f1b228529ae49b0f85ab89bcdb6c365df401558.zip | |
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>
Diffstat (limited to 'fs/ocfs2/suballoc.c')
| -rw-r--r-- | fs/ocfs2/suballoc.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 8521942f5af2..481017e1dac5 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1251,7 +1251,7 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh, { struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data; struct journal_head *jh; - int ret; + int ret = 1; if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap)) return 0; @@ -1259,14 +1259,18 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh, if (!buffer_jbd(bg_bh)) return 1; - jh = bh2jh(bg_bh); - spin_lock(&jh->b_state_lock); - bg = (struct ocfs2_group_desc *) jh->b_committed_data; - if (bg) - ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap); - else - ret = 1; - spin_unlock(&jh->b_state_lock); + jbd_lock_bh_journal_head(bg_bh); + if (buffer_jbd(bg_bh)) { + jh = bh2jh(bg_bh); + spin_lock(&jh->b_state_lock); + bg = (struct ocfs2_group_desc *) jh->b_committed_data; + if (bg) + ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap); + else + ret = 1; + spin_unlock(&jh->b_state_lock); + } + jbd_unlock_bh_journal_head(bg_bh); return ret; } |