Merge tag 'nfs-for-5.6-3' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client bugfixes from Anna Schumaker:
 "These are mostly fscontext fixes, but there is also one that fixes
  collisions seen in fscache:

   - Ensure the fs_context has the correct fs_type when mounting and
     submounting

   - Fix leaking of ctx->nfs_server.hostname

   - Add minor version to fscache key to prevent collisions"

* tag 'nfs-for-5.6-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  nfs: add minor version to nfs_server_key for fscache
  NFS: Fix leak of ctx->nfs_server.hostname
  NFS: Don't hard-code the fs_type when submounting
  NFS: Ensure the fs_context has the correct fs_type before mounting

Author: torvalds

fs/nfs/client.c

@@ -153,6 +153,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
 		goto error_0;
 
+	clp->cl_minorversion = cl_init->minorversion;
 	clp->cl_nfs_mod = cl_init->nfs_mod;
 	if (!try_module_get(clp->cl_nfs_mod->owner))
 		goto error_dealloc;

fs/nfs/fs_context.c

@@ -832,6 +832,8 @@ static int nfs_parse_source(struct fs_context *fc,
 	if (len > maxnamlen)
 		goto out_hostname;
 
+	kfree(ctx->nfs_server.hostname);
+
 	/* N.B. caller will free nfs_server.hostname in all cases */
 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
 	if (!ctx->nfs_server.hostname)
@@ -1240,6 +1242,13 @@ static int nfs_fs_context_validate(struct fs_context *fc)
 		}
 		ctx->nfs_mod = nfs_mod;
 	}
+
+	/* Ensure the filesystem context has the correct fs_type */
+	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
+		module_put(fc->fs_type->owner);
+		__module_get(ctx->nfs_mod->nfs_fs->owner);
+		fc->fs_type = ctx->nfs_mod->nfs_fs;
+	}
 	return 0;
 
 out_no_device_name:

fs/nfs/fscache.c

@@ -31,6 +31,7 @@ static DEFINE_SPINLOCK(nfs_fscache_keys_lock);
 struct nfs_server_key {
 	struct {
 		uint16_t	nfsversion;		/* NFS protocol version */
+		uint32_t	minorversion;		/* NFSv4 minor version */
 		uint16_t	family;			/* address family */
 		__be16		port;			/* IP port */
 	} hdr;
@@ -55,6 +56,7 @@ void nfs_fscache_get_client_cookie(struct nfs_client *clp)
 
 	memset(&key, 0, sizeof(key));
 	key.hdr.nfsversion = clp->rpc_ops->version;
+	key.hdr.minorversion = clp->cl_minorversion;
 	key.hdr.family = clp->cl_addr.ss_family;
 
 	switch (clp->cl_addr.ss_family) {

fs/nfs/namespace.c

@@ -153,7 +153,7 @@ struct vfsmount *nfs_d_automount(struct path *path)
 	/* Open a new filesystem context, transferring parameters from the
 	 * parent superblock, including the network namespace.
 	 */
-	fc = fs_context_for_submount(&nfs_fs_type, path->dentry);
+	fc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry);
 	if (IS_ERR(fc))
 		return ERR_CAST(fc);
 

fs/nfs/nfs4client.c

@@ -216,7 +216,6 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
 	INIT_LIST_HEAD(&clp->cl_ds_clients);
 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
-	clp->cl_minorversion = cl_init->minorversion;
 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
 	clp->cl_mig_gen = 1;
 #if IS_ENABLED(CONFIG_NFS_V4_1)