Unable to create files in subdirectories under unionfs-fuse mountpoint: `Permission Denied`

[nukemiko]

Hello! Can you help me. I'm getting what may be some unexpected behavior. While I trying to create a file in subdirectories under unionfs-fuse mountpoint, I got an error Permission Denied:

miketsu@Miketsu:/dev/pts/3 → ~ (0)
$ > unionfs /home/miketsu/__delta__=RW:/home/miketsu/__stock__=RO /home/miketsu/__mount__
miketsu@Miketsu:/dev/pts/3 → ~ (0)
$ > l __stock__ __delta__ __mount__
__delta__:
total 4.0K
-rwxr-xr-x 1 miketsu miketsu 371 Mar  5 17:48 app_install.vdf*
drwxr-xr-x 1 miketsu miketsu  18 Mar 14 23:31 this-is-another-directory-in-__delta__/

__mount__:
total 4.0K
-rwxr-xr-x 1 miketsu miketsu 371 Mar  5 17:48 app_install.vdf*
drwxr-xr-x 1 miketsu miketsu  18 Mar 14 23:31 this-is-another-directory-in-__delta__/
drwxr-xr-x 1 miketsu miketsu   0 Mar 14 23:26 this-is-directory-in-__stock__/

__stock__:
total 0
drwxr-xr-x 1 miketsu miketsu 0 Mar 14 23:26 this-is-directory-in-__stock__/
miketsu@Miketsu:/dev/pts/3 → ~ (0)
$ > touch __mount__/test1
miketsu@Miketsu:/dev/pts/3 → ~ (0)
$ > touch __mount__/this-is-directory-in-__stock__/test2
touch: cannot touch '__mount__/this-is-directory-in-__stock__/test2': Permission denied
miketsu@Miketsu:/dev/pts/3 → ~ (1)
$ > echo 'Changed' >> __mount__/this-is-another-directory-in-__delta__/test-edit 
miketsu@Miketsu:/dev/pts/3 → ~ (0)
$ >

As you can see, I am the owner of these directories and files, and their all have read and write permission. The following debug output (unionfs -d):

FUSE library version: 3.14.0
nullpath_ok: 0
Ignoring invalid max threads value 4294967295 > max (100000).
unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0
INIT: 7.38
flags=0x73fffffb
max_readahead=0x00020000
   INIT: 7.38
   flags=0x4040f039
   max_readahead=0x00020000
   max_write=0x00100000
   max_background=0
   congestion_threshold=0
   time_gran=1
   unique: 2, success, outsize: 80
unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 56, pid: 14346
getattr[NULL] /
   unique: 4, success, outsize: 120
unique: 6, opcode: LOOKUP (1), nodeid: 1, insize: 71, pid: 14346
LOOKUP /this-is-directory-in-__stock__
getattr[NULL] /this-is-directory-in-__stock__
   NODEID: 2
   unique: 6, success, outsize: 144
unique: 8, opcode: LOOKUP (1), nodeid: 2, insize: 46, pid: 14346
LOOKUP /this-is-directory-in-__stock__/test2
getattr[NULL] /this-is-directory-in-__stock__/test2
   unique: 8, error: -2 (No such file or directory), outsize: 16
unique: 10, opcode: CREATE (35), nodeid: 2, insize: 62, pid: 14346
create flags: 0x8841 /this-is-directory-in-__stock__/test2 0100644 umask=0022
   unique: 10, error: -13 (Permission denied), outsize: 16
unique: 12, opcode: LOOKUP (1), nodeid: 2, insize: 46, pid: 14346
LOOKUP /this-is-directory-in-__stock__/test2
getattr[NULL] /this-is-directory-in-__stock__/test2
   unique: 12, error: -2 (No such file or directory), outsize: 16

Is this a bug? Is there any solution for this?

[xandaaah]

You set stock to use read only. Just change the RO to an RW next to the path of stock in the mount command and it should work just fine.