ext4: fix the deadlock in mpage_da_map_and_submit()

If ext4_jbd2_file_inode() in mpage_da_map_and_submit() fails due to
journal abort, this function returns to caller without unlocking the
page.  It leads to the deadlock, and the patch fixes this issue by
calling mpage_da_submit_io().

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 8 insertions, 5 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ecb572591924..ff6aace0bb3c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1552,9 +1552,11 @@ static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
 
                 if (ext4_should_order_data(mpd->inode)) {
                         err = ext4_jbd2_file_inode(handle, mpd->inode);
-                        if (err)
+                        if (err) {
                                 /* Only if the journal is aborted */
-                                return;
+                                mpd->retval = err;
+                                goto submit_io;
+                        }
                 }
         }
 
@@ -2294,11 +2296,12 @@ retry:
                         ret = 0;
                 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
                         /*
-                         * got one extent now try with
-                         * rest of the pages
+                         * Got one extent now try with rest of the pages.
+                         * If mpd.retval is set -EIO, journal is aborted.
+                         * So we don't need to write any more.
                          */
                         pages_written += mpd.pages_written;
-                        ret = 0;
+                        ret = mpd.retval;
                         io_done = 1;
                 } else if (wbc->nr_to_write)
                         /*