maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I828EV CVE: NA Reference: https://lore.kernel.org/linux-ext4/20230911155822.kbg2xayc7ys24kay@quack3/T/... -------------------------------- JBD2 makes sure journal data is fallen on fs device by sync_blockdev(), however, other process could intercept the EIO information from bdev's mapping, which leads journal recovering successful even EIO occurs during data written back to fs device. We found this problem in our product, iscsi + multipath is chosen for block device of ext4. Unstable network may trigger kpartx to rescan partitions in device mapper layer. Detailed process is shown as following: mount kpartx irq jbd2_journal_recover do_one_pass memcpy(nbh->b_data, obh->b_data) // copy data to fs dev from journal mark_buffer_dirty // mark bh dirty vfs_read generic_file_read_iter // dio filemap_write_and_wait_range __filemap_fdatawrite_range do_writepages block_write_full_folio submit_bh_wbc >> EIO occurs in disk << end_buffer_async_write mark_buffer_write_io_error mapping_set_error set_bit(AS_EIO, &mapping->flags) // set! filemap_check_errors test_and_clear_bit(AS_EIO, &mapping->flags) // clear! err2 = sync_blockdev filemap_write_and_wait filemap_check_errors test_and_clear_bit(AS_EIO, &mapping->flags) // false err2 = 0 Filesystem is mounted successfully even data from journal is failed written into disk, and ext4/ocfs2 could become corrupted. Fix it by comparing the wb_err state in fs block device before recovering and after recovering. Fetch a reproducer in [Link]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217888 Cc: stable@vger.kernel.org Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: Zhang Yi <yi.zhang@huawei.com> --- v1->v3: Initialize wb_err. Untialized wb_err could be same with mapping->wb_err(eg. EIO without ERRSEQ_SEEN). When EIO occurs again, mapping->wb_err won't be changed, and wb_err is still same with mapping->wb_err. fs/jbd2/recovery.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 9e4537349380..cdf4c553f058 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -292,6 +292,8 @@ int jbd2_journal_recover(journal_t *journal) journal_superblock_t * sb; struct recovery_info info; + errseq_t wb_err; + struct address_space *mapping; memset(&info, 0, sizeof(info)); sb = journal->j_superblock; @@ -309,6 +311,9 @@ int jbd2_journal_recover(journal_t *journal) return 0; } + wb_err = 0; + mapping = journal->j_fs_dev->bd_inode->i_mapping; + errseq_check_and_advance(&mapping->wb_err, &wb_err); err = do_one_pass(journal, &info, PASS_SCAN); if (!err) err = do_one_pass(journal, &info, PASS_REVOKE); @@ -327,6 +332,9 @@ int jbd2_journal_recover(journal_t *journal) jbd2_journal_clear_revoke(journal); err2 = sync_blockdev(journal->j_fs_dev); + if (!err) + err = err2; + err2 = errseq_check_and_advance(&mapping->wb_err, &wb_err); if (!err) err = err2; /* Make sure all replayed data is on permanent storage */ -- 2.31.1