fs/nfs/nfs4client.c

Source file repositories/reference/linux-study-clean/fs/nfs/nfs4client.c

File Facts

System
Linux kernel
Corpus path
fs/nfs/nfs4client.c
Extension
.c
Size
31872 bytes
Lines
1204
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct nfs4_ds_server {
	struct list_head	list;   /* ds_clp->cl_ds_clients */
	struct rpc_clnt		*rpc_clnt;
};

/**
 * nfs4_find_ds_client - Common lookup case for DS I/O
 * @ds_clp: pointer to the DS's nfs_client
 * @flavor: rpc auth flavour to match
 */
static struct nfs4_ds_server *
nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
{
	struct nfs4_ds_server *dss;

	rcu_read_lock();
	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
			continue;
		goto out;
	}
	dss = NULL;
out:
	rcu_read_unlock();
	return dss;
}

static struct nfs4_ds_server *
nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
			   struct nfs4_ds_server *new)
{
	struct nfs4_ds_server *dss;

	spin_lock(&ds_clp->cl_lock);
	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
			continue;
		goto out;
	}
	if (new)
		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
	dss = new;
out:
	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
	return dss;
}

static struct nfs4_ds_server *
nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
{
	struct nfs4_ds_server *dss;

	dss = kmalloc_obj(*dss, GFP_NOFS);
	if (dss == NULL)
		return ERR_PTR(-ENOMEM);

	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
	if (IS_ERR(dss->rpc_clnt)) {
		int err = PTR_ERR(dss->rpc_clnt);
		kfree (dss);
		return ERR_PTR(err);
	}
	INIT_LIST_HEAD(&dss->list);

	return dss;
}

static void
nfs4_free_ds_server(struct nfs4_ds_server *dss)
{
	rpc_release_client(dss->rpc_clnt);
	kfree(dss);
}

/**
 * nfs4_find_or_create_ds_client - Find or create a DS rpc client
 * @ds_clp: pointer to the DS's nfs_client
 * @inode: pointer to the inode
 *
 * Find or create a DS rpc client with th MDS server rpc client auth flavor
 * in the nfs_client cl_ds_clients list.
 */
struct rpc_clnt *
nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
{
	struct nfs4_ds_server *dss, *new;
	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;

	dss = nfs4_find_ds_client(ds_clp, flavor);
	if (dss != NULL)

Annotation

Implementation Notes