On Tue 19-09-23 09:25:25, Zhihao Cheng wrote: > 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@xxxxxxxxxxxxxxx > Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> > Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx> > --- > 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. Yeah, good catch. The patch still looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > fs/jbd2/recovery.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c > index c269a7d29a46..5b771a3d8d9a 100644 > --- a/fs/jbd2/recovery.c > +++ b/fs/jbd2/recovery.c > @@ -289,6 +289,8 @@ 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; > @@ -306,6 +308,9 @@ 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 */ > -- > 2.39.2 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
