NFS: add sysfs shutdown knob

Within each nfs_server sysfs tree, add an entry named "shutdown".  Writing
1 to this file will set the cl_shutdown bit on the rpc_clnt structs
associated with that mount.  If cl_shutdown is set, the task scheduler
immediately returns -EIO for new tasks.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Benjamin Coddington 2023-06-15 14:07:30 -04:00 committed by Trond Myklebust
parent f4057ffd0e
commit d9615d166c
4 changed files with 61 additions and 2 deletions

View File

@ -12,6 +12,7 @@
#include <linux/string.h>
#include <linux/nfs_fs.h>
#include <linux/rcupdate.h>
#include <linux/lockd/lockd.h>
#include "nfs4_fs.h"
#include "netns.h"
@ -216,6 +217,50 @@ void nfs_netns_sysfs_destroy(struct nfs_net *netns)
}
}
static ssize_t
shutdown_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
bool shutdown = server->flags & NFS_MOUNT_SHUTDOWN;
return sysfs_emit(buf, "%d\n", shutdown);
}
static ssize_t
shutdown_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
struct nfs_server *server;
int ret, val;
server = container_of(kobj, struct nfs_server, kobj);
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val != 1)
return -EINVAL;
/* already shut down? */
if (server->flags & NFS_MOUNT_SHUTDOWN)
goto out;
server->flags |= NFS_MOUNT_SHUTDOWN;
server->client->cl_shutdown = 1;
server->nfs_client->cl_rpcclient->cl_shutdown = 1;
if (!IS_ERR(server->client_acl))
server->client_acl->cl_shutdown = 1;
if (server->nlm_host)
server->nlm_host->h_rpcclnt->cl_shutdown = 1;
out:
return count;
}
static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);
#define RPC_CLIENT_NAME_SIZE 64
void nfs_sysfs_link_rpc_client(struct nfs_server *server,
@ -259,9 +304,16 @@ void nfs_sysfs_add_server(struct nfs_server *server)
ret = kobject_init_and_add(&server->kobj, &nfs_sb_ktype,
&nfs_kset->kobj, "server-%d", server->s_sysfs_id);
if (ret < 0)
if (ret < 0) {
pr_warn("NFS: nfs sysfs add server-%d failed (%d)\n",
server->s_sysfs_id, ret);
return;
}
ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_shutdown.attr,
nfs_netns_server_namespace(&server->kobj));
if (ret < 0)
pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
server->s_sysfs_id, ret);
}
EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);

View File

@ -154,6 +154,7 @@ struct nfs_server {
#define NFS_MOUNT_WRITE_EAGER 0x01000000
#define NFS_MOUNT_WRITE_WAIT 0x02000000
#define NFS_MOUNT_TRUNK_DISCOVERY 0x04000000
#define NFS_MOUNT_SHUTDOWN 0x08000000
unsigned int fattr_valid; /* Valid attributes */
unsigned int caps; /* server capabilities */

View File

@ -63,7 +63,8 @@ struct rpc_clnt {
cl_discrtry : 1,/* disconnect before retry */
cl_noretranstimeo: 1,/* No retransmit timeouts */
cl_autobind : 1,/* use getport() */
cl_chatty : 1;/* be verbose */
cl_chatty : 1,/* be verbose */
cl_shutdown : 1;/* rpc immediate -EIO */
struct xprtsec_parms cl_xprtsec; /* transport security policy */
struct rpc_rtt * cl_rtt; /* RTO estimator data */

View File

@ -1724,6 +1724,11 @@ call_start(struct rpc_task *task)
trace_rpc_request(task);
if (task->tk_client->cl_shutdown) {
rpc_call_rpcerror(task, -EIO);
return;
}
/* Increment call count (version might not be valid for ping) */
if (clnt->cl_program->version[clnt->cl_vers])
clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;