fault_inject.c
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/*
* Copyright (c) 2011 Bryan Schumaker <bjschuma@netapp.com>
*
* Uses debugfs to create fault injection points for client testing
*/
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/nsproxy.h>
#include <linux/sunrpc/addr.h>
#include <asm/uaccess.h>
#include "state.h"
#include "netns.h"
struct nfsd_fault_inject_op {
char *file;
u64 (*forget)(struct nfs4_client *, u64);
u64 (*print)(struct nfs4_client *, u64);
};
static struct nfsd_fault_inject_op inject_ops[] = {
{
.file = "forget_clients",
.forget = nfsd_forget_client,
.print = nfsd_print_client,
},
{
.file = "forget_locks",
.forget = nfsd_forget_client_locks,
.print = nfsd_print_client_locks,
},
{
.file = "forget_openowners",
.forget = nfsd_forget_client_openowners,
.print = nfsd_print_client_openowners,
},
{
.file = "forget_delegations",
.forget = nfsd_forget_client_delegations,
.print = nfsd_print_client_delegations,
},
{
.file = "recall_delegations",
.forget = nfsd_recall_client_delegations,
.print = nfsd_print_client_delegations,
},
};
static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op);
static struct dentry *debug_dir;
static void nfsd_inject_set(struct nfsd_fault_inject_op *op, u64 val)
{
u64 count = 0;
if (val == 0)
printk(KERN_INFO "NFSD Fault Injection: %s (all)", op->file);
else
printk(KERN_INFO "NFSD Fault Injection: %s (n = %llu)", op->file, val);
nfs4_lock_state();
count = nfsd_for_n_state(val, op->forget);
nfs4_unlock_state();
printk(KERN_INFO "NFSD: %s: found %llu", op->file, count);
}
static void nfsd_inject_set_client(struct nfsd_fault_inject_op *op,
struct sockaddr_storage *addr,
size_t addr_size)
{
char buf[INET6_ADDRSTRLEN];
struct nfs4_client *clp;
u64 count;
nfs4_lock_state();
clp = nfsd_find_client(addr, addr_size);
if (clp) {
count = op->forget(clp, 0);
rpc_ntop((struct sockaddr *)&clp->cl_addr, buf, sizeof(buf));
printk(KERN_INFO "NFSD [%s]: Client %s had %llu state object(s)\n", op->file, buf, count);
}
nfs4_unlock_state();
}
static void nfsd_inject_get(struct nfsd_fault_inject_op *op, u64 *val)
{
nfs4_lock_state();
*val = nfsd_for_n_state(0, op->print);
nfs4_unlock_state();
}
static ssize_t fault_inject_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
static u64 val;
char read_buf[25];
size_t size, ret;
loff_t pos = *ppos;
if (!pos)
nfsd_inject_get(file_inode(file)->i_private, &val);
size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
if (pos < 0)
return -EINVAL;
if (pos >= size || !len)
return 0;
if (len > size - pos)
len = size - pos;
ret = copy_to_user(buf, read_buf + pos, len);
if (ret == len)
return -EFAULT;
len -= ret;
*ppos = pos + len;
return len;
}
static ssize_t fault_inject_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
char write_buf[INET6_ADDRSTRLEN];
size_t size = min(sizeof(write_buf) - 1, len);
struct net *net = current->nsproxy->net_ns;
struct sockaddr_storage sa;
u64 val;
if (copy_from_user(write_buf, buf, size))
return -EFAULT;
write_buf[size] = '\0';
size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
if (size > 0)
nfsd_inject_set_client(file_inode(file)->i_private, &sa, size);
else {
val = simple_strtoll(write_buf, NULL, 0);
nfsd_inject_set(file_inode(file)->i_private, val);
}
return len; /* on success, claim we got the whole input */
}
static const struct file_operations fops_nfsd = {
.owner = THIS_MODULE,
.read = fault_inject_read,
.write = fault_inject_write,
};
void nfsd_fault_inject_cleanup(void)
{
debugfs_remove_recursive(debug_dir);
}
int nfsd_fault_inject_init(void)
{
unsigned int i;
struct nfsd_fault_inject_op *op;
umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
debug_dir = debugfs_create_dir("nfsd", NULL);
if (!debug_dir)
goto fail;
for (i = 0; i < NUM_INJECT_OPS; i++) {
op = &inject_ops[i];
if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
goto fail;
}
return 0;
fail:
nfsd_fault_inject_cleanup();
return -ENOMEM;
}