diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2020-06-23 16:00:33 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2020-06-29 14:48:02 -0400 |
| commit | 681370f4b00af0fcc65bbfb9f82de526ab7ceb0a (patch) | |
| tree | f9b3be891505d9420ca222fc14452bb7750315f5 /fs/nfsd | |
| parent | 22cf8419f1319ff87ec759d0ebdff4cbafaee832 (diff) | |
nfsd4: fix nfsdfs reference count loop
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: 2c830dd7209b ("nfsd: persist nfsd filesystem across mounts")
Reported-and-Tested-by: Luo Xiaogang <lxgrxd@163.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 8 | ||||
| -rw-r--r-- | fs/nfsd/nfsctl.c | 22 | ||||
| -rw-r--r-- | fs/nfsd/nfsd.h | 3 |
3 files changed, 22 insertions, 11 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index bb3d2c32664a..cce2510b2cca 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -7912,9 +7912,14 @@ nfs4_state_start_net(struct net *net) struct nfsd_net *nn = net_generic(net, nfsd_net_id); int ret; - ret = nfs4_state_create_net(net); + ret = get_nfsdfs(net); if (ret) return ret; + ret = nfs4_state_create_net(net); + if (ret) { + mntput(nn->nfsd_mnt); + return ret; + } locks_start_grace(net, &nn->nfsd4_manager); nfsd4_client_tracking_init(net); if (nn->track_reclaim_completes && nn->reclaim_str_hashtbl_size == 0) @@ -7984,6 +7989,7 @@ nfs4_state_shutdown_net(struct net *net) nfsd4_client_tracking_exit(net); nfs4_state_destroy_net(net); + mntput(nn->nfsd_mnt); } void diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index b68e96681522..cf98a81ca1ea 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -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); diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 36cdd81b6688..57c832d1b30f 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -90,6 +90,8 @@ void nfsd_destroy(struct net *net); bool i_am_nfsd(void); +int get_nfsdfs(struct net *); + struct nfsdfs_client { struct kref cl_ref; void (*cl_release)(struct kref *kref); @@ -100,6 +102,7 @@ struct dentry *nfsd_client_mkdir(struct nfsd_net *nn, struct nfsdfs_client *ncl, u32 id, const struct tree_descr *); void nfsd_client_rmdir(struct dentry *dentry); + #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) #ifdef CONFIG_NFSD_V2_ACL extern const struct svc_version nfsd_acl_version2; |