Description of problem:
There is a difference in the behavior of permissions handling when dealing with paths that have a trailing slash between versions 7.1 and 8.0.

In version 8.0: Permissions are applied directly to the specified path. For example, if a user has rw (read/write) permissions to the path /volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227/, they can create files and folders directly within this directory.

In version 7.1: Permissions are applied differently. Users cannot create files or folders directly within the path, but they can create files and folders in subdirectories under the path. 

Assign rw permissions to a path such as /volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227/.
Attempt to create a file or folder directly within this path:
In 8.0, this works as expected.
In 7.1, the file or folder creation fails unless it is within a subdirectory.


Test steps on 8.0: 
[root@ceph-amk-nfs-h8x293-node11 ~]# ceph fs subvolume create cephfs subvol_1
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# ceph fs subvolume getpath cephfs subvol_1
/volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227
[root@ceph-amk-nfs-h8x293-node11 ~]# ceph fs authorize cephfs client.test_auth / r /volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227/ rw
[client.test_auth]
	key = AQDIzgJnd/vbIhAAYWa38+Yqeky9lJKY4oLgtg==
	caps mds = "allow r fsname=cephfs, allow rw fsname=cephfs path=/volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227/"
	caps mon = "allow r fsname=cephfs"
	caps osd = "allow rw tag cephfs data=cephfs"
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# mkdir /mnt/cephfuse
[root@ceph-amk-nfs-h8x293-node11 ~]# ceph auth get client.test_auth -o /etc/ceph/ceph.client.test_auth.keyring 
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# ceph-fuse -n client.test_auth /mnt/cephfuse/ -r / --client_fs cephfs 
2024-10-06T13:55:41.303-0400 7fe331d53480 -1 init, newargv = 0x55ae1392be40 newargc=15
ceph-fuse[11272]: starting ceph client
ceph-fuse[11272]: starting fuse
[root@ceph-amk-nfs-h8x293-node11 ~]# 
[root@ceph-amk-nfs-h8x293-node11 ~]# cd /mnt/cephfuse/
[root@ceph-amk-nfs-h8x293-node11 cephfuse]# ls
volumes
[root@ceph-amk-nfs-h8x293-node11 cephfuse]# touch auth_test_file
touch: cannot touch 'auth_test_file': Permission denied
[root@ceph-amk-nfs-h8x293-node11 cephfuse]# cd volumes/_nogroup/subvol_1/c6b9ef66-8107-4622-ba8a-cb809d92e227/
[root@ceph-amk-nfs-h8x293-node11 c6b9ef66-8107-4622-ba8a-cb809d92e227]# touch auth_test_file
[root@ceph-amk-nfs-h8x293-node11 c6b9ef66-8107-4622-ba8a-cb809d92e227]# 


In 7.1: 
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph fs subvolume getpath cephfs subvol_1
/volumes/_nogroup/subvol_1/33a3d82f-93b9-470d-b937-e2b20552deb8
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph fs authorize cephfs client.test_auth / r /volumes/_nogroup/subvol_1/33a3d82f-93b9-470d-b937-e2b20552deb8/ rw
[client.test_auth]
	key = AQCknQNnmZj8ExAAXhaEPrmyPtKzk7MMxZmjQA==
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph auth get client.test_auth -o /etc/ceph/ceph.client.test_auth.keyring 
[root@ceph-amk-top-bh9z9m-node8 ~]#  mkdir /mnt/cephfuse
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph-fuse -n client.test_auth /mnt/cephfuse/ -r / --client_fs cephfs 
2024-10-07T04:37:07.430-0400 7fd06d40b480 -1 init, newargv = 0x7fd05c004bd0 newargc=15
ceph-fuse[6552]: starting ceph client
ceph-fuse[6552]: starting fuse
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph auth get ceph-fuse -n client.test_auth /mnt/cephfuse/ -r / --client_fs cephfs ^C
[root@ceph-amk-top-bh9z9m-node8 ~]# ^C
[root@ceph-amk-top-bh9z9m-node8 ~]# ceph auth get client.test_auth
[client.test_auth]
	key = AQCknQNnmZj8ExAAXhaEPrmyPtKzk7MMxZmjQA==
	caps mds = "allow r fsname=cephfs, allow rw fsname=cephfs path=/volumes/_nogroup/subvol_1/33a3d82f-93b9-470d-b937-e2b20552deb8/"
	caps mon = "allow r fsname=cephfs"
	caps osd = "allow rw tag cephfs data=cephfs"
[root@ceph-amk-top-bh9z9m-node8 ~]# cd /mnt/cephfuse/
[root@ceph-amk-top-bh9z9m-node8 cephfuse]# touch auth_test_file
touch: cannot touch 'auth_test_file': Permission denied
[root@ceph-amk-top-bh9z9m-node8 cephfuse]# cd volumes/_nogroup/subvol_1/33a3d82f-93b9-470d-b937-e2b20552deb8/
[root@ceph-amk-top-bh9z9m-node8 33a3d82f-93b9-470d-b937-e2b20552deb8]# 
[root@ceph-amk-top-bh9z9m-node8 33a3d82f-93b9-470d-b937-e2b20552deb8]# touch auth_test_file
touch: cannot touch 'auth_test_file': Permission denied


Version-Release number of selected component (if applicable):

[root@ceph-amk-top-bh9z9m-node8 dir1]# ceph versions
{
    "mon": {
        "ceph version 18.2.1-251.el9cp (81688db791aa982863476facb32440cb7210c828) reef (stable)": 3
    },
    "mgr": {
        "ceph version 18.2.1-251.el9cp (81688db791aa982863476facb32440cb7210c828) reef (stable)": 2
    },
    "osd": {
        "ceph version 18.2.1-251.el9cp (81688db791aa982863476facb32440cb7210c828) reef (stable)": 16
    },
    "mds": {
        "ceph version 18.2.1-251.el9cp (81688db791aa982863476facb32440cb7210c828) reef (stable)": 5
    },
    "overall": {
        "ceph version 18.2.1-251.el9cp (81688db791aa982863476facb32440cb7210c828) reef (stable)": 26
    }
}



How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info: