[PATCH 2/2] jffs2: handle INO_STATE_CLEARING in jffs2_do_read_inode()

[Hou Tao]

For inode that fails to be created midway, GC procedure may
try to GC its dnode, and in the following case BUG() will be
triggered:

CPU 0                       CPU 1
in jffs2_do_create()        in jffs2_garbage_collect_pass()

jffs2_write_dnode succeed
// for dirent
jffs2_reserve_space fail

                            inum = ic->ino
                            nlink = ic->pino_nlink (> 0)

iget_failed
  make_bad_inode
    remove_inode_hash
  iput
    jffs2_evict_inode
      jffs2_do_clear_inode
        jffs2_set_inocache_state(INO_STATE_CLEARING)

                            jffs2_gc_fetch_inode
                              jffs2_iget
                                // a new inode is created because
                                // the old inode had been unhashed
                                iget_locked
                              jffs2_do_read_inode
                                jffs2_get_ino_cache
                                // assert BUG()
                                f->inocache->state = INO_STATE_CLEARING

Fix it by waiting for its state changes to INO_STATE_CHECKEDABSENT.

Fixes: 67e345d17ff8 ("[JFFS2] Prevent ino cache removal for inodes in use")
Cc: sta...@vger.kernel.org
Signed-off-by: Hou Tao <hout...@huawei.com>
---
 fs/jffs2/readinode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index 389ea53ea487..0bae0583106e 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -1328,6 +1328,7 @@ int jffs2_do_read_inode(struct jffs2_sb_info *c, struct 
jffs2_inode_info *f,
 
                case INO_STATE_CHECKING:
                case INO_STATE_GC:
+               case INO_STATE_CLEARING:
                        /* If it's in either of these states, we need
                           to wait for whoever's got it to finish and
                           put it back. */
-- 
2.16.2.dirty