=============================================================================
BUG  ceph_inode_info  (Not  tainted):  Objects  remaining  in  ceph_inode_info  on  __kmem_cache_shutdown()
-----------------------------------------------------------------------------
Disabling  lock  debugging  due  to  kernel  taint
INFO:  Slab  0x000000001037cfd2  objects=23  used=1  fp=0x000000006c0dc265  flags=0x2fffff80008100
CPU:  0  PID:  27086  Comm:  rmmod  Tainted:  G  B  4.15.0-rc8+  #7
Hardware  name:  Fedora  Project  OpenStack  Nova,  BIOS  seabios-1.7.5-11.el7  04/01/2014
Call  Trace:
dump_stack+0x5c/0x7c
slab_err+0xb4/0xe0
?  on_each_cpu_mask+0x24/0x60
?  on_each_cpu_cond+0xad/0x140
?  __kmalloc+0x1be/0x1f0
?  __kmem_cache_shutdown+0x175/0x3c0
__kmem_cache_shutdown+0x196/0x3c0
shutdown_cache+0x13/0x1a0
kmem_cache_destroy+0x1e4/0x220
destroy_caches+0x16/0x46  [ceph]
SyS_delete_module+0x168/0x240
?  exit_to_usermode_loop+0x6e/0x93
entry_SYSCALL_64_fastpath+0x20/0x83
RIP:  0033:0x7f8650f87c27
RSP:  002b:00007ffda546ff88  EFLAGS:  00000206
INFO:  Object  0x00000000568b3053  @offset=0
kmem_cache_destroy  ceph_inode_info:  Slab  cache  still  has  objects
CPU:  0  PID:  27086  Comm:  rmmod  Tainted:  G  B  4.15.0-rc8+  #7
Hardware  name:  Fedora  Project  OpenStack  Nova,  BIOS  seabios-1.7.5-11.el7  04/01/2014
Call  Trace:
dump_stack+0x5c/0x7c
kmem_cache_destroy+0x203/0x220
destroy_caches+0x16/0x46  [ceph]
SyS_delete_module+0x168/0x240
?  exit_to_usermode_loop+0x6e/0x93
entry_SYSCALL_64_fastpath+0x20/0x83
RIP:  0033:0x7f8650f87c27
RSP:  002b:00007ffda546ff88  EFLAGS:  00000206
=============================================================================
BUG  ceph_dentry_info  (Tainted:  G  B  ):  Objects  remaining  in  ceph_dentry_info  on  __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO:  Slab  0x00000000aabb3f88  objects=51  used=1  fp=0x000000002436421a  flags=0x2fffff80000100
CPU:  0  PID:  27086  Comm:  rmmod  Tainted:  G  B  4.15.0-rc8+  #7
Hardware  name:  Fedora  Project  OpenStack  Nova,  BIOS  seabios-1.7.5-11.el7  04/01/2014
Call  Trace:
dump_stack+0x5c/0x7c
slab_err+0xb4/0xe0
?  on_each_cpu_cond+0xad/0x140
?  __kmalloc+0x1be/0x1f0
?  __kmem_cache_shutdown+0x175/0x3c0
__kmem_cache_shutdown+0x196/0x3c0
shutdown_cache+0x13/0x1a0
kmem_cache_destroy+0x1e4/0x220
destroy_caches+0x3a/0x46  [ceph]
SyS_delete_module+0x168/0x240
?  exit_to_usermode_loop+0x6e/0x93
entry_SYSCALL_64_fastpath+0x20/0x83
RIP:  0033:0x7f8650f87c27
RSP:  002b:00007ffda546ff88  EFLAGS:  00000206
INFO:  Object  0x0000000034be48a6  @offset=0
kmem_cache_destroy  ceph_dentry_info:  Slab  cache  still  has  objects
CPU:  0  PID:  27086  Comm:  rmmod  Tainted:  G  B  4.15.0-rc8+  #7
Hardware  name:  Fedora  Project  OpenStack  Nova,  BIOS  seabios-1.7.5-11.el7  04/01/2014
Call  Trace:
dump_stack+0x5c/0x7c
kmem_cache_destroy+0x203/0x220
destroy_caches+0x3a/0x46  [ceph]
SyS_delete_module+0x168/0x240
?  exit_to_usermode_loop+0x6e/0x93
entry_SYSCALL_64_fastpath+0x20/0x83
RIP:  0033:0x7f8650f87c27

Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
---
 fs/ceph/super.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index a62d2a9..26526601 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -836,7 +836,6 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 	int err;
 	unsigned long started = jiffies;  /* note the start time */
 	struct dentry *root;
-	int first = 0;   /* first vfsmount for this super_block */
 
 	dout("mount start %p\n", fsc);
 	mutex_lock(&fsc->client->mount_mutex);
@@ -861,17 +860,17 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 			path = fsc->mount_options->server_path + 1;
 			dout("mount opening path %s\n", path);
 		}
+
+		err = ceph_fs_debugfs_init(fsc);
+		if (err < 0)
+			goto out;
+
 		root = open_root_dentry(fsc, path, started);
 		if (IS_ERR(root)) {
 			err = PTR_ERR(root);
 			goto out;
 		}
 		fsc->sb->s_root = dget(root);
-		first = 1;
-
-		err = ceph_fs_debugfs_init(fsc);
-		if (err < 0)
-			goto fail;
 	} else {
 		root = dget(fsc->sb->s_root);
 	}
@@ -881,11 +880,6 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
 	mutex_unlock(&fsc->client->mount_mutex);
 	return root;
 
-fail:
-	if (first) {
-		dput(fsc->sb->s_root);
-		fsc->sb->s_root = NULL;
-	}
 out:
 	mutex_unlock(&fsc->client->mount_mutex);
 	return ERR_PTR(err);
