jbd2: abort journal if free a async write error metadata buffer

If we free a metadata buffer which has been failed to async write out
in the background, the jbd2 checkpoint procedure will not detect this
failure in jbd2_log_do_checkpoint(), so it may lead to filesystem
inconsistency after cleanup journal tail. This patch abort the journal
if free a buffer has write_io_error flag to prevent potential further
inconsistency.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20200620025427.1756360-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index e65e0ac..6250c9f 100644 (file)
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -2120,6 +2120,7 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal,
 {
        struct buffer_head *head;
        struct buffer_head *bh;
+       bool has_write_io_error = false;
        int ret = 0;
 
        J_ASSERT(PageLocked(page));
@@ -2144,11 +2145,26 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal,
                jbd2_journal_put_journal_head(jh);
                if (buffer_jbd(bh))
                        goto busy;
+
+               /*
+                * If we free a metadata buffer which has been failed to
+                * write out, the jbd2 checkpoint procedure will not detect
+                * this failure and may lead to filesystem inconsistency
+                * after cleanup journal tail.
+                */
+               if (buffer_write_io_error(bh)) {
+                       pr_err("JBD2: Error while async write back metadata bh %llu.",
+                              (unsigned long long)bh->b_blocknr);
+                       has_write_io_error = true;
+               }
        } while ((bh = bh->b_this_page) != head);
 
        ret = try_to_free_buffers(page);
 
 busy:
+       if (has_write_io_error)
+               jbd2_journal_abort(journal, -EIO);
+
        return ret;
 }