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Message-ID: <20220715125152.4022726-1-chengzhihao1@huawei.com>
Date: Fri, 15 Jul 2022 20:51:52 +0800
From: Zhihao Cheng <chengzhihao1@...wei.com>
To: <tytso@....edu>, <jack@...e.com>, <ritesh.list@...il.com>,
<lczerner@...hat.com>, <akpm@...l.org>, <shaggy@...tin.ibm.com>
CC: <linux-ext4@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<chengzhihao1@...wei.com>, <yukuai3@...wei.com>
Subject: [PATCH] jbd2: Fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted
Following process will fail assertion 'jh->b_frozen_data == NULL' in
jbd2_journal_dirty_metadata():
jbd2_journal_commit_transaction
unlink(dir/a)
jh->b_transaction = trans1
jh->b_jlist = BJ_Metadata
journal->j_running_transaction = NULL
trans1->t_state = T_COMMIT
unlink(dir/b)
handle->h_trans = trans2
do_get_write_access
jh->b_modified = 0
jh->b_frozen_data = frozen_buffer
jh->b_next_transaction = trans2
jbd2_journal_dirty_metadata
is_handle_aborted
is_journal_aborted // return false
--> jbd2 abort <--
while (commit_transaction->t_buffers)
if (is_journal_aborted)
jbd2_journal_refile_buffer
__jbd2_journal_refile_buffer
WRITE_ONCE(jh->b_transaction,
jh->b_next_transaction)
WRITE_ONCE(jh->b_next_transaction, NULL)
__jbd2_journal_file_buffer(jh, BJ_Reserved)
J_ASSERT_JH(jh, jh->b_frozen_data == NULL) // assertion failure !
The reproducer (See detail in [Link]) reports:
------------[ cut here ]------------
kernel BUG at fs/jbd2/transaction.c:1629!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 2 PID: 584 Comm: unlink Tainted: G W
5.19.0-rc6-00115-g4a57a8400075-dirty #697
RIP: 0010:jbd2_journal_dirty_metadata+0x3c5/0x470
RSP: 0018:ffffc90000be7ce0 EFLAGS: 00010202
Call Trace:
<TASK>
__ext4_handle_dirty_metadata+0xa0/0x290
ext4_handle_dirty_dirblock+0x10c/0x1d0
ext4_delete_entry+0x104/0x200
__ext4_unlink+0x22b/0x360
ext4_unlink+0x275/0x390
vfs_unlink+0x20b/0x4c0
do_unlinkat+0x42f/0x4c0
__x64_sys_unlink+0x37/0x50
do_syscall_64+0x35/0x80
After journal aborting, __jbd2_journal_refile_buffer() is executed with
holding @jh->b_state_lock, we can fix it by moving 'is_handle_aborted()'
into the area protected by @jh->b_state_lock.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216251
Fixes: 470decc613ab20 ("[PATCH] jbd2: initial copy of files from jbd")
Signed-off-by: Zhihao Cheng <chengzhihao1@...wei.com>
---
fs/jbd2/transaction.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index e9c308ae475f..e0377f558eb1 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1486,8 +1486,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
struct journal_head *jh;
int ret = 0;
- if (is_handle_aborted(handle))
- return -EROFS;
if (!buffer_jbd(bh))
return -EUCLEAN;
@@ -1534,6 +1532,18 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
journal = transaction->t_journal;
spin_lock(&jh->b_state_lock);
+ if (is_handle_aborted(handle)) {
+ /*
+ * Check journal aborting with @jh->b_state_lock locked,
+ * since 'jh->b_transaction' could be replaced with
+ * 'jh->b_next_transaction' during old transaction
+ * committing if journal aborted, which may fail
+ * assertion on 'jh->b_frozen_data == NULL'.
+ */
+ ret = -EROFS;
+ goto out_unlock_bh;
+ }
+
if (jh->b_modified == 0) {
/*
* This buffer's got modified and becoming part
--
2.31.1
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