In fa0d7e3, we use rcu free inode instead of freeing the inode directly. It causes a crash when we rmmod immediately after we umount the volume[1]. So we need to call rcu_barrier after we kill_sb so that the inode is freed before we do rmmod. The idea is inspired by Aneesh Kumar. rcu_barrier will wait for all callbacks to end before preceding. The original patch was done by Tao Ma, but synchronize_rcu() is not enough here. 1. http://marc.info/?l=linux-fsdevel&m=129680863330185&w=2 Cc: Nick Piggin <npiggin@xxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Chris Mason <chris.mason@xxxxxxxxxx> Tested-by: Tao Ma <boyu.mt@xxxxxxxxxx> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx> --- fs/super.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/fs/super.c b/fs/super.c index 74e149e..7e9dd4c 100644 --- a/fs/super.c +++ b/fs/super.c @@ -177,6 +177,11 @@ void deactivate_locked_super(struct super_block *s) struct file_system_type *fs = s->s_type; if (atomic_dec_and_test(&s->s_active)) { fs->kill_sb(s); + /* + * We need to call rcu_barrier so all the delayed rcu free + * inodes are flushed before we release the fs module. + */ + rcu_barrier(); put_filesystem(fs); put_super(s); } else { -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
