fault_inject.c

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/*
 * Copyright (c) 2011 Bryan Schumaker <[email protected]>
 *
 * 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 "state.h"
#include "fault_inject.h"

struct nfsd_fault_inject_op {
    char *file;
    void (*func)(u64);
};

static struct nfsd_fault_inject_op inject_ops[] = {
    {
        .file   = "forget_clients",
        .func   = nfsd_forget_clients,
    },
    {
        .file   = "forget_locks",
        .func   = nfsd_forget_locks,
    },
    {
        .file   = "forget_openowners",
        .func   = nfsd_forget_openowners,
    },
    {
        .file   = "forget_delegations",
        .func   = nfsd_forget_delegations,
    },
    {
        .file   = "recall_delegations",
        .func   = nfsd_recall_delegations,
    },
};

static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op);
static struct dentry *debug_dir;

static int nfsd_inject_set(void *op_ptr, u64 val)
{
    struct nfsd_fault_inject_op *op = op_ptr;

    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);

    op->func(val);
    return 0;
}

static int nfsd_inject_get(void *data, u64 *val)
{
    *val = 0;
    return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(fops_nfsd, nfsd_inject_get, nfsd_inject_set, "%llu\n");

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;
}