ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 04:33:26 +02:00
Code Issues Packages Projects Releases Wiki Activity

nfsd4: fix nfsdfs reference count loop

Browse Source 
We don't drop the reference on the nfsdfs filesystem with
mntput(nn->nfsd_mnt) until nfsd_exit_net(), but that won't be called
until the nfsd module's unloaded, and we can't unload the module as long
as there's a reference on nfsdfs.  So this prevents module unloading.

Fixes: 2c830dd720 ("nfsd: persist nfsd filesystem across mounts")
Reported-and-Tested-by:  Luo Xiaogang <lxgrxd@163.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields
2020-06-23 16:00:33 -04:00
parent 22cf8419f1
commit 681370f4b0
3 changed files with 22 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
fs/nfsd/nfsctl.c
View File

@@ -1424,6 +1424,18 @@ static struct file_system_type nfsd_fs_type = {
};
MODULE_ALIAS_FS("nfsd");
int get_nfsdfs(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct vfsmount *mnt;
mnt = vfs_kern_mount(&nfsd_fs_type, SB_KERNMOUNT, "nfsd", NULL);
if (IS_ERR(mnt))
return PTR_ERR(mnt);
nn->nfsd_mnt = mnt;
return 0;
}
#ifdef CONFIG_PROC_FS
static int create_proc_exports_entry(void)
{
@@ -1451,7 +1463,6 @@ unsigned int nfsd_net_id;
static __net_init int nfsd_init_net(struct net *net)
{
int retval;
struct vfsmount *mnt;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
retval = nfsd_export_init(net);
@@ -1478,16 +1489,8 @@ static __net_init int nfsd_init_net(struct net *net)
init_waitqueue_head(&nn->ntf_wq);
seqlock_init(&nn->boot_lock);
mnt = vfs_kern_mount(&nfsd_fs_type, SB_KERNMOUNT, "nfsd", NULL);
if (IS_ERR(mnt)) {
retval = PTR_ERR(mnt);
goto out_mount_err;
}
nn->nfsd_mnt = mnt;
return 0;
out_mount_err:
nfsd_reply_cache_shutdown(nn);
out_drc_error:
nfsd_idmap_shutdown(net);
out_idmap_error:
@@ -1500,7 +1503,6 @@ static __net_exit void nfsd_exit_net(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
mntput(nn->nfsd_mnt);
nfsd_reply_cache_shutdown(nn);
nfsd_idmap_shutdown(net);
nfsd_export_shutdown(net);