linux-imx

/*

 * Copyright (C) 2003 Sistina Software (UK) Limited.

 * Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.

 *

 * This file is released under the GPL.

 */

​

#include <linux/device-mapper.h>

​

#include <linux/module.h>

#include <linux/init.h>

#include <linux/blkdev.h>

#include <linux/bio.h>

#include <linux/slab.h>

​

#define DM_MSG_PREFIX "flakey"

​

#define all_corrupt_bio_flags_match(bio, fc)    \

    (((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)

​

/*

 * Flakey: Used for testing only, simulates intermittent,

 * catastrophic device failure.

 */

struct flakey_c {

    struct dm_dev *dev;

    unsigned long start_time;

    sector_t start;

    unsigned up_interval;

    unsigned down_interval;

    unsigned long flags;

    unsigned corrupt_bio_byte;

    unsigned corrupt_bio_rw;

    unsigned corrupt_bio_value;

    unsigned corrupt_bio_flags;

};

​

enum feature_flag_bits {

    DROP_WRITES,

    ERROR_WRITES

};

​

struct per_bio_data {

    bool bio_submitted;

};

​

static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,

              struct dm_target *ti)

{

    int r;

    unsigned argc;

    const char *arg_name;

​

    static const struct dm_arg _args[] = {

        {0, 6, "Invalid number of feature args"},

        {1, UINT_MAX, "Invalid corrupt bio byte"},

        {0, 255, "Invalid corrupt value to write into bio byte (0-255)"},

        {0, UINT_MAX, "Invalid corrupt bio flags mask"},

    };

​

    /* No feature arguments supplied. */

    if (!as->argc)

        return 0;

​

    r = dm_read_arg_group(_args, as, &argc, &ti->error);

    if (r)

        return r;

​

    while (argc) {

        arg_name = dm_shift_arg(as);

        argc--;

​

        if (!arg_name) {

            ti->error = "Insufficient feature arguments";

            return -EINVAL;

        }

​

        /*

         * drop_writes

         */

        if (!strcasecmp(arg_name, "drop_writes")) {

            if (test_and_set_bit(DROP_WRITES, &fc->flags)) {

                ti->error = "Feature drop_writes duplicated";

                return -EINVAL;

            } else if (test_bit(ERROR_WRITES, &fc->flags)) {

                ti->error = "Feature drop_writes conflicts with feature error_writes";

                return -EINVAL;

            }

​

            continue;

        }

​