kernel-ark/fs/nfsd/fault_inject.c
Bryan Schumaker d7cc431edd NFSD: Add a custom file operations structure for fault injection
Controlling the read and write functions allows me to add in "forget
client w.x.y.z", since we won't be limited to reading and writing only
u64 values.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-12-03 09:59:02 -05:00

147 lines
3.3 KiB
C

/*
* 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 <asm/uaccess.h>
#include "state.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_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->f_dentry->d_inode->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[24];
size_t size = min(sizeof(write_buf), len) - 1;
u64 val;
if (copy_from_user(write_buf, buf, size))
return -EFAULT;
val = simple_strtoll(write_buf, NULL, 0);
nfsd_inject_set(file->f_dentry->d_inode->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;
}