While appending an extent to a file, it will call these functions:
ocfs2_insert_extent
-> call ocfs2_grow_tree() if there's no free rec
-> ocfs2_add_branch add a new branch to extent tree,
now rec[0] in the leaf of rightmost path is empty
-> ocfs2_do_insert_extent
-> ocfs2_rotate_tree_right
-> ocfs2_extend_rotate_transaction
-> jbd2_journal_restart if jbd2_journal_extend fail
-> ocfs2_insert_path
-> ocfs2_extend_trans
-> jbd2_journal_restart if jbd2_journal_extend fail
-> ocfs2_insert_at_leaf
-> ocfs2_et_update_clusters
Function jbd2_journal_restart() may be called and it may happened that
buffers dirtied in ocfs2_add_branch() are committed
while buffers dirtied in ocfs2_insert_at_leaf() and
ocfs2_et_update_clusters() are not.
So an empty rec[0] is left in rightmost path which will cause
read-only filesystem when call ocfs2_commit_truncate()
with the error message: "Inode %lu has an empty extent record".
This is not a serious problem, so remove the rightmost path when call
ocfs2_commit_truncate().
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d0c97d52f5