[thirdparty/mdadm.git] / sysfs.c

/*
 * sysfs - extract md related information from sysfs.  Part of:
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@suse.de>
 */

#include        "mdadm.h"
#include        "dlink.h"
#include        "xmalloc.h"

#include        <dirent.h>
#include        <ctype.h>

#define MAX_SYSFS_PATH_LEN      120

struct dev_sysfs_rule {
        struct dev_sysfs_rule *next;
        char *devname;
        int uuid[4];
        int uuid_set;
        struct sysfs_entry {
                struct sysfs_entry *next;
                char *name;
                char *value;
        } *entry;
};

int load_sys(char *path, char *buf, int len)
{
        int fd = open(path, O_RDONLY);
        int n;
        if (fd < 0)
                return -1;
        n = read(fd, buf, len);
        close(fd);
        if (n <0 || n >= len)
                return -1;
        buf[n] = 0;
        if (n && buf[n-1] == '\n')
                buf[n-1] = 0;
        return 0;
}

void sysfs_free(struct mdinfo *sra)
{
        while (sra) {
                struct mdinfo *sra2 = sra->next;
                while (sra->devs) {
                        struct mdinfo *d = sra->devs;
                        sra->devs = d->next;
                        free(d->bb.entries);
                        free(d);
                }
                free(sra->bb.entries);
                free(sra);
                sra = sra2;
        }
}

mapping_t sysfs_memb_states[] = {
        {"external_bbl", MEMB_STATE_EXTERNAL_BBL},
        {"blocked", MEMB_STATE_BLOCKED},
        {"spare", MEMB_STATE_SPARE},
        {"write_mostly", MEMB_STATE_WRITE_MOSTLY},
        {"in_sync", MEMB_STATE_IN_SYNC},
        {"faulty", MEMB_STATE_FAULTY},
        {"remove",  MEMB_STATE_REMOVE},
        {NULL,  MEMB_STATE_UNKNOWN}
};

char *map_memb_state(memb_state_t state)
{
        return map_num_s(sysfs_memb_states, state);
}

/**
 * write_attr() - write value to fd, don't check errno.
 * @attr: value to write.
 * @fd: file descriptor write to.
 *
 * Size to write is calculated by strlen().
 */
mdadm_status_t write_attr(const char *value, const int fd)
{
        return sysfs_write_descriptor(fd, value, strlen(value), NULL);
}

/**
 * sysfs_write_descriptor()- wrapper for write(), projected to be used with sysfs.
 * @fd: file descriptor.
 * @value: value to set.
 * @len: length of the value.
 * @errno_p: On write() failure, buffer to copy errno value, might be NULL.
 *
 * Errors are differentiated, because (at least theoretically) kernel may not process whole string
 * and it may or may not be a problem (it depends on implementation in kernel). Decision belongs to
 * caller then.
 * Generally, it should be safe to check if @errno_p changed to determine if error occurred.
 */
mdadm_status_t sysfs_write_descriptor(const int fd, const char *value, const ssize_t len,
                                      int *errno_p)
{
        ssize_t ret;

        ret = write(fd, value, len);
        if (ret == -1) {
                if (errno_p)
                        *errno_p = errno;
                return MDADM_STATUS_ERROR;
        }

        if (ret != len)
                return MDADM_STATUS_UNDEF;

        return MDADM_STATUS_SUCCESS;
}

/**
 * sysfs_set_memb_state_fd() - write to md/<memb>/state file.
 * @fd: open file descriptor to the file.
 * @state: enum value describing value to write
 * @err: errno value pointer in case of error.
 *
 * This is helper to avoid inlining values, they are extracted from map now.
 */
mdadm_status_t sysfs_set_memb_state_fd(int fd, memb_state_t state, int *err)
{
        const char *val = map_memb_state(state);

        return sysfs_write_descriptor(fd, val, strlen(val), err);
}

/**
 * sysfs_set_memb_state() - write to member disk state file.
 * @array_devnm: kernel name of the array.
 * @memb_devnm: kernel name of member device.
 * @state: value to write.
 *
 * Function expects that the device exists, error is unconditionally printed.
 */
mdadm_status_t sysfs_set_memb_state(char *array_devnm, char *memb_devnm, memb_state_t state)
{
        int state_fd = sysfs_open_memb_attr(array_devnm, memb_devnm, "state", O_RDWR);

        if (!is_fd_valid(state_fd)) {
                pr_err("Cannot open file descriptor to %s in array %s, aborting.\n",
                       memb_devnm, array_devnm);
                        return MDADM_STATUS_ERROR;
        }

        return sysfs_set_memb_state_fd(state_fd, state, NULL);

        close_fd(&state_fd);
}

/**
 * sysfs_get_container_devnm() - extract container device name.
 * @mdi: md_info describes member array, with GET_VERSION option.
 * @buf: buf to fill, must be MD_NAME_MAX.
 *
 * External array version is in format {/,-}<container_devnm>/<array_index>
 * Extract container_devnm from it and safe it in @buf.
 */
void sysfs_get_container_devnm(struct mdinfo *mdi, char *buf)
{
        char *p;

        assert(is_subarray(mdi->text_version));

        /* Skip first special sign */
        snprintf(buf, MD_NAME_MAX, "%s", mdi->text_version + 1);

        /* Remove array index */
        p = strchr(buf, '/');
        if (p)
                *p = 0;
}

/**
 * sysfs_open_memb_attr() - helper to get sysfs attr descriptor for member device.
 * @array_devnm: array kernel device name.
 * @memb_devnm: member device kernel device name.
 * @attr: requested sysfs attribute.
 * @oflag: open() flags.
 *
 * To refer member device directory, we need to append "dev-" before the member device name.
 */
int sysfs_open_memb_attr(char *array_devnm, char *memb_devnm, char *attr, int oflag)
{
        char path[PATH_MAX];

        snprintf(path, PATH_MAX, "/sys/block/%s/md/dev-%s/%s", array_devnm, memb_devnm, attr);

        return open(path, oflag);
}

int sysfs_open(char *devnm, char *devname, char *attr)
{
        char fname[MAX_SYSFS_PATH_LEN];
        int fd;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/", devnm);
        if (devname) {
                strncat(fname, devname, MAX_SYSFS_PATH_LEN - strlen(fname));
                strncat(fname, "/", MAX_SYSFS_PATH_LEN - strlen(fname));
        }
        strncat(fname, attr, MAX_SYSFS_PATH_LEN - strlen(fname));
        fd = open(fname, O_RDWR);
        if (fd < 0 && errno == EACCES)
                fd = open(fname, O_RDONLY);
        return fd;
}

void sysfs_init_dev(struct mdinfo *mdi, dev_t devid)
{
        snprintf(mdi->sys_name,
                 sizeof(mdi->sys_name), "dev-%s", devid2kname(devid));
}

int sysfs_init(struct mdinfo *mdi, int fd, char *devnm)
{
        struct stat stb;
        char fname[MAX_SYSFS_PATH_LEN];
        int retval = -ENODEV;

        mdi->sys_name[0] = 0;
        if (fd >= 0)
                devnm = fd2devnm(fd);

        if (devnm == NULL)
                goto out;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md", devnm);

        if (stat(fname, &stb))
                goto out;
        if (!S_ISDIR(stb.st_mode))
                goto out;
        strncpy(mdi->sys_name, devnm, sizeof(mdi->sys_name) - 1);

        retval = 0;
out:
        return retval;
}

/* If fd >= 0, get the array it is open on, else use devnm. */
struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
{
        char fname[PATH_MAX];
        char buf[PATH_MAX];
        char *base;
        char *dbase;
        struct mdinfo *sra;
        struct mdinfo *dev, **devp;
        DIR *dir = NULL;
        struct dirent *de;

        sra = xcalloc(1, sizeof(*sra));
        if (sysfs_init(sra, fd, devnm)) {
                free(sra);
                return NULL;
        }

        sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
        base = fname + strlen(fname);

        sra->devs = NULL;
        if (options & GET_VERSION) {
                strcpy(base, "metadata_version");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                if (str_is_none(buf) == true) {
                        sra->array.major_version =
                                sra->array.minor_version = -1;
                        strcpy(sra->text_version, "");
                } else if (strncmp(buf, "external:", 9) == 0) {
                        sra->array.major_version = -1;
                        sra->array.minor_version = -2;
                        strcpy(sra->text_version, buf+9);
                        sra->text_version[sizeof(sra->text_version) - 1] = '\0';
                } else {
                        sscanf(buf, "%d.%d",
                               &sra->array.major_version,
                               &sra->array.minor_version);
                        strcpy(sra->text_version, buf);
                }
        }
        if (options & GET_LEVEL) {
                strcpy(base, "level");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->array.level = map_name(pers, buf);
        }
        if (options & GET_LAYOUT) {
                strcpy(base, "layout");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->array.layout = strtoul(buf, NULL, 0);
        }
        if (options & (GET_DISKS|GET_STATE)) {
                strcpy(base, "raid_disks");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->array.raid_disks = strtoul(buf, NULL, 0);
        }
        if (options & GET_COMPONENT) {
                strcpy(base, "component_size");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->component_size = strtoull(buf, NULL, 0);
                /* sysfs reports "K", but we want sectors */
                sra->component_size *= 2;
        }
        if (options & GET_CHUNK) {
                strcpy(base, "chunk_size");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->array.chunk_size = strtoul(buf, NULL, 0);
        }
        if (options & GET_CACHE) {
                strcpy(base, "stripe_cache_size");
                if (load_sys(fname, buf, sizeof(buf)))
                        /* Probably level doesn't support it */
                        sra->cache_size = 0;
                else
                        sra->cache_size = strtoul(buf, NULL, 0);
        }
        if (options & GET_MISMATCH) {
                strcpy(base, "mismatch_cnt");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->mismatch_cnt = strtoul(buf, NULL, 0);
        }
        if (options & GET_SAFEMODE) {
                int scale = 1;
                int dot = 0;
                unsigned i;
                unsigned long msec;
                size_t len;

                strcpy(base, "safe_mode_delay");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;

                /* remove a period, and count digits after it */
                len = strlen(buf);
                for (i = 0; i < len; i++) {
                        if (dot) {
                                if (isdigit(buf[i])) {
                                        buf[i-1] = buf[i];
                                        scale *= 10;
                                }
                                buf[i] = 0;
                        } else if (buf[i] == '.') {
                                dot=1;
                                buf[i] = 0;
                        }
                }
                msec = strtoul(buf, NULL, 10);
                msec = (msec * 1000) / scale;
                sra->safe_mode_delay = msec;
        }
        if (options & GET_BITMAP_LOCATION) {
                strcpy(base, "bitmap/location");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                if (strncmp(buf, "file", 4) == 0)
                        sra->bitmap_offset = 1;
                else if (str_is_none(buf) == true)
                        sra->bitmap_offset = 0;
                else if (buf[0] == '+')
                        sra->bitmap_offset = strtol(buf+1, NULL, 10);
                else
                        goto abort;
        }

        if (options & GET_ARRAY_STATE) {
                strcpy(base, "array_state");
                if (load_sys(fname, buf, sizeof(buf)))
                        goto abort;
                sra->array_state = map_name(sysfs_array_states, buf);
        }

        if (options & GET_CONSISTENCY_POLICY) {
                strcpy(base, "consistency_policy");
                if (load_sys(fname, buf, sizeof(buf)))
                        sra->consistency_policy = CONSISTENCY_POLICY_UNKNOWN;
                else
                        sra->consistency_policy = map_name(consistency_policies,
                                                           buf);
        }

        if (! (options & GET_DEVS))
                return sra;

        /* Get all the devices as well */
        *base = 0;
        dir = opendir(fname);
        if (!dir)
                goto abort;
        sra->array.spare_disks = 0;
        sra->array.active_disks = 0;
        sra->array.failed_disks = 0;
        sra->array.working_disks = 0;

        devp = &sra->devs;
        sra->devs = NULL;
        while ((de = readdir(dir)) != NULL) {
                char *ep;
                if (de->d_ino == 0 ||
                    strncmp(de->d_name, "dev-", 4) != 0)
                        continue;
                strcpy(base, de->d_name);
                dbase = base + strlen(base);
                *dbase++ = '/';

                dev = xcalloc(1, sizeof(*dev));

                /* Always get slot, major, minor */
                strcpy(dbase, "slot");
                if (load_sys(fname, buf, sizeof(buf))) {
                        /* hmm... unable to read 'slot' maybe the device
                         * is going away?
                         */
                        strcpy(dbase, "block");
                        if (readlink(fname, buf, sizeof(buf)) < 0 &&
                            errno != ENAMETOOLONG) {
                                /* ...yup device is gone */
                                free(dev);
                                continue;
                        } else {
                                /* slot is unreadable but 'block' link
                                 * still intact... something bad is happening
                                 * so abort
                                 */
                                free(dev);
                                goto abort;
                        }

                }
                strcpy(dev->sys_name, de->d_name);
                dev->sys_name[sizeof(dev->sys_name) - 1] = '\0';
                dev->disk.raid_disk = strtoul(buf, &ep, 10);
                if (*ep) dev->disk.raid_disk = -1;

                sra->array.nr_disks++;
                strcpy(dbase, "block/dev");
                if (load_sys(fname, buf, sizeof(buf))) {
                        /* assume this is a stale reference to a hot
                         * removed device
                         */
                        if (!(options & GET_DEVS_ALL)) {
                                free(dev);
                                continue;
                        }
                } else {
                        sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
                }

                if (!(options & GET_DEVS_ALL)) {
                        /* special case check for block devices that can go 'offline' */
                        strcpy(dbase, "block/device/state");
                        if (load_sys(fname, buf, sizeof(buf)) == 0 &&
                            strncmp(buf, "offline", 7) == 0) {
                                free(dev);
                                continue;
                        }
                }

                /* finally add this disk to the array */
                *devp = dev;
                devp = & dev->next;
                dev->next = NULL;

                if (options & GET_OFFSET) {
                        strcpy(dbase, "offset");
                        if (load_sys(fname, buf, sizeof(buf)))
                                goto abort;
                        dev->data_offset = strtoull(buf, NULL, 0);
                        strcpy(dbase, "new_offset");
                        if (load_sys(fname, buf, sizeof(buf)) == 0)
                                dev->new_data_offset = strtoull(buf, NULL, 0);
                        else
                                dev->new_data_offset = dev->data_offset;
                }
                if (options & GET_SIZE) {
                        strcpy(dbase, "size");
                        if (load_sys(fname, buf, sizeof(buf)))
                                goto abort;
                        dev->component_size = strtoull(buf, NULL, 0) * 2;
                }
                if (options & GET_STATE) {
                        dev->disk.state = 0;
                        strcpy(dbase, "state");
                        if (load_sys(fname, buf, sizeof(buf)))
                                goto abort;
                        if (strstr(buf, "faulty"))
                                dev->disk.state |= (1<<MD_DISK_FAULTY);
                        else {
                                sra->array.working_disks++;
                                if (strstr(buf, "in_sync")) {
                                        dev->disk.state |= (1<<MD_DISK_SYNC);
                                        sra->array.active_disks++;
                                }
                                if (dev->disk.state == 0)
                                        sra->array.spare_disks++;
                        }
                }
                if (options & GET_ERROR) {
                        strcpy(buf, "errors");
                        if (load_sys(fname, buf, sizeof(buf)))
                                goto abort;
                        dev->errors = strtoul(buf, NULL, 0);
                }
        }

        if ((options & GET_STATE) && sra->array.raid_disks)
                sra->array.failed_disks = sra->array.raid_disks -
                        sra->array.active_disks - sra->array.spare_disks;

        closedir(dir);
        return sra;

 abort:
        if (dir)
                closedir(dir);
        sysfs_free(sra);
        return NULL;
}

int sysfs_attr_match(const char *attr, const char *str)
{
        /* See if attr, read from a sysfs file, matches
         * str.  They must either be the same, or attr can
         * have a trailing newline or comma
         */
        while (*attr && *str && *attr == *str) {
                attr++;
                str++;
        }

        if (*str || (*attr && *attr != ',' && *attr != '\n'))
                return 0;
        return 1;
}

int sysfs_match_word(const char *word, char **list)
{
        int n;
        for (n=0; list[n]; n++)
                if (sysfs_attr_match(word, list[n]))
                        break;
        return n;
}

unsigned long long get_component_size(int fd)
{
        /* Find out the component size of the array.
         * We cannot trust GET_ARRAY_INFO ioctl as it's
         * size field is only 32bits.
         * So look in /sys/block/mdXXX/md/component_size
         *
         * This returns in units of sectors.
         */
        struct stat stb;
        char fname[MAX_SYSFS_PATH_LEN];
        int n;
        if (fstat(fd, &stb))
                return 0;
        snprintf(fname, MAX_SYSFS_PATH_LEN,
                 "/sys/block/%s/md/component_size", stat2devnm(&stb));
        fd = open(fname, O_RDONLY);
        if (fd < 0)
                return 0;
        n = read(fd, fname, sizeof(fname));
        close(fd);
        if (n < 0 || n == sizeof(fname))
                return 0;
        fname[n] = 0;
        return strtoull(fname, NULL, 10) * 2;
}

int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
                  char *name, char *val)
{
        char fname[MAX_SYSFS_PATH_LEN];
        int fd;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
                sra->sys_name, dev?dev->sys_name:"", name);
        fd = open(fname, O_WRONLY);
        if (fd < 0)
                return -1;

        if (write_attr(val, fd)) {
                pr_err("failed to write '%s' to '%s' (%s)\n", val, fname, strerror(errno));
                close(fd);
                return -1;
        }

        close(fd);
        return 0;
}

int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
                  char *name, unsigned long long val)
{
        char valstr[50];
        sprintf(valstr, "%llu", val);
        return sysfs_set_str(sra, dev, name, valstr);
}

int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
                         char *name, long long val)
{
        char valstr[50];
        sprintf(valstr, "%lli", val);
        return sysfs_set_str(sra, dev, name, valstr);
}

int sysfs_uevent(struct mdinfo *sra, char *event)
{
        char fname[MAX_SYSFS_PATH_LEN];
        int fd;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/uevent",
                sra->sys_name);
        fd = open(fname, O_WRONLY);
        if (fd < 0)
                return -1;

        if (write_attr(event, fd)) {
                pr_err("failed to write '%s' to '%s' (%s)\n", event, fname, strerror(errno));
                close(fd);
                return -1;
        }

        close(fd);
        return 0;
}

int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
{
        char fname[MAX_SYSFS_PATH_LEN];
        struct stat st;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
                sra->sys_name, dev?dev->sys_name:"", name);

        return stat(fname, &st) == 0;
}

int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
                       char *name)
{
        char fname[MAX_SYSFS_PATH_LEN];
        int fd;

        snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
                sra->sys_name, dev?dev->sys_name:"", name);
        fd = open(fname, O_RDWR);
        if (fd < 0)
                fd = open(fname, O_RDONLY);
        return fd;
}

int sysfs_fd_get_ll(int fd, unsigned long long *val)
{
        char buf[50];
        int n;
        char *ep;

        lseek(fd, 0, 0);
        n = read(fd, buf, sizeof(buf));
        if (n <= 0 || n == sizeof(buf))
                return -2;
        buf[n] = 0;
        *val = strtoull(buf, &ep, 0);
        if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
                return -1;
        return 0;
}

int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
                       char *name, unsigned long long *val)
{
        int n;
        int fd;

        fd = sysfs_get_fd(sra, dev, name);
        if (fd < 0)
                return -1;
        n = sysfs_fd_get_ll(fd, val);
        close(fd);
        return n;
}

int sysfs_fd_get_two(int fd, unsigned long long *v1, unsigned long long *v2)
{
        /* two numbers in this sysfs file, either
         *  NNN (NNN)
         * or
         *  NNN / NNN
         */
        char buf[80];
        int n;
        char *ep, *ep2;

        lseek(fd, 0, 0);
        n = read(fd, buf, sizeof(buf));
        if (n <= 0 || n == sizeof(buf))
                return -2;
        buf[n] = 0;
        *v1 = strtoull(buf, &ep, 0);
        if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
                return -1;
        while (*ep == ' ' || *ep == '/' || *ep == '(')
                ep++;
        *v2 = strtoull(ep, &ep2, 0);
        if (ep2 == ep || (*ep2 != 0 && *ep2 != '\n' && *ep2 != ' ' && *ep2 != ')')) {
                *v2 = *v1;
                return 1;
        }
        return 2;
}

int sysfs_get_two(struct mdinfo *sra, struct mdinfo *dev,
                  char *name, unsigned long long *v1, unsigned long long *v2)
{
        int n;
        int fd;

        fd = sysfs_get_fd(sra, dev, name);
        if (fd < 0)
                return -1;
        n = sysfs_fd_get_two(fd, v1, v2);
        close(fd);
        return n;
}

int sysfs_fd_get_str(int fd, char *val, int size)
{
        int n;

        lseek(fd, 0, 0);
        n = read(fd, val, size);
        if (n <= 0 || n == size)
                return -1;
        val[n] = 0;
        return n;
}

int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
                       char *name, char *val, int size)
{
        int n;
        int fd;

        fd = sysfs_get_fd(sra, dev, name);
        if (fd < 0)
                return -1;
        n = sysfs_fd_get_str(fd, val, size);
        close(fd);
        return n;
}

int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
{
        unsigned long sec;
        unsigned long msec;
        char delay[30];

        sec = ms / 1000;
        msec = ms % 1000;

        sprintf(delay, "%ld.%03ld\n", sec, msec);
        /*             this '\n' ^ needed for kernels older than 2.6.28 */
        return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
}

int sysfs_set_array(struct mdinfo *info)
{
        int rv = 0;
        char ver[100];
        int raid_disks = info->array.raid_disks;

        ver[0] = 0;
        if (info->array.major_version == -1 &&
            info->array.minor_version == -2) {
                char buf[SYSFS_MAX_BUF_SIZE];

                strcat(strcpy(ver, "external:"), info->text_version);

                /* meta version might already be set if we are setting
                 * new geometry for a reshape.  In that case we don't
                 * want to over-write the 'readonly' flag that is
                 * stored in the metadata version.  So read the current
                 * version first, and preserve the flag
                 */
                if (sysfs_get_str(info, NULL, "metadata_version",
                                  buf, sizeof(buf)) > 0)
                        if (strlen(buf) >= 9 && buf[9] == '-')
                                ver[9] = '-';

                if (sysfs_set_str(info, NULL, "metadata_version", ver) < 0) {
                        pr_err("This kernel does not support external metadata.\n");
                        return 1;
                }
        }
        if (info->array.level < 0)
                return 0; /* FIXME */
        rv |= sysfs_set_str(info, NULL, "level",
                            map_num_s(pers, info->array.level));
        if (info->reshape_active && info->delta_disks != UnSet)
                raid_disks -= info->delta_disks;
        rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
        rv |= sysfs_set_num(info, NULL, "chunk_size", info->array.chunk_size);
        rv |= sysfs_set_num(info, NULL, "layout", info->array.layout);
        rv |= sysfs_set_num(info, NULL, "component_size", info->component_size/2);
        if (info->custom_array_size) {
                int rc;

                rc = sysfs_set_num(info, NULL, "array_size",
                                   info->custom_array_size/2);
                if (rc && errno == ENOENT) {
                        pr_err("This kernel does not have the md/array_size attribute, the array may be larger than expected\n");
                        rc = 0;
                }
                rv |= rc;
        }

        if (info->array.level > 0)
                rv |= sysfs_set_num(info, NULL, "resync_start", info->resync_start);

        if (info->reshape_active) {
                rv |= sysfs_set_num(info, NULL, "reshape_position",
                                    info->reshape_progress);
                rv |= sysfs_set_num(info, NULL, "chunk_size", info->new_chunk);
                rv |= sysfs_set_num(info, NULL, "layout", info->new_layout);
                rv |= sysfs_set_num(info, NULL, "raid_disks",
                                    info->array.raid_disks);
                /* We don't set 'new_level' here.  That can only happen
                 * once the reshape completes.
                 */
        }

        if (info->consistency_policy == CONSISTENCY_POLICY_PPL) {
                char *policy = map_num_s(consistency_policies,
                                            info->consistency_policy);

                if (sysfs_set_str(info, NULL, "consistency_policy", policy)) {
                        pr_err("This kernel does not support PPL. Falling back to consistency-policy=resync.\n");
                        info->consistency_policy = CONSISTENCY_POLICY_RESYNC;
                }
        }

        return rv;
}

int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
{
        char dv[PATH_MAX];
        char nm[PATH_MAX];
        char *dname;
        int rv;
        int i;

        sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
        rv = sysfs_set_str(sra, NULL, "new_dev", dv);
        if (rv)
                return rv;

        memset(nm, 0, sizeof(nm));
        dname = devid2kname(makedev(sd->disk.major, sd->disk.minor));

        snprintf(sd->sys_name, sizeof(sd->sys_name), "dev-%s", dname);

        /* test write to see if 'recovery_start' is available */
        if (resume && sd->recovery_start < MaxSector &&
            sysfs_set_num(sra, sd, "recovery_start", 0)) {
                sysfs_set_str(sra, sd, "state", "remove");
                return -1;
        }

        rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
        rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
        if (!is_container(sra->array.level)) {
                if (sra->consistency_policy == CONSISTENCY_POLICY_PPL) {
                        rv |= sysfs_set_num(sra, sd, "ppl_sector", sd->ppl_sector);
                        rv |= sysfs_set_num(sra, sd, "ppl_size", sd->ppl_size);
                }
                if (sd->recovery_start == MaxSector)
                        /* This can correctly fail if array isn't started,
                         * yet, so just ignore status for now.
                         */
                        sysfs_set_str(sra, sd, "state", "insync");
                if (sd->disk.raid_disk >= 0)
                        rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
                if (resume)
                        sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
        }
        if (sd->bb.supported) {
                if (sysfs_set_str(sra, sd, "state", "external_bbl")) {
                        /*
                         * backward compatibility - if kernel doesn't support
                         * bad blocks for external metadata, let it continue
                         * as long as there are none known so far
                         */
                        if (sd->bb.count) {
                                pr_err("The kernel has no support for bad blocks in external metadata\n");
                                return -1;
                        }
                }

                for (i = 0; i < sd->bb.count; i++) {
                        char s[30];
                        const struct md_bb_entry *entry = &sd->bb.entries[i];

                        snprintf(s, sizeof(s) - 1, "%llu %d\n", entry->sector,
                                 entry->length);
                        rv |= sysfs_set_str(sra, sd, "bad_blocks", s);
                }
        }
        return rv;
}

int sysfs_disk_to_scsi_id(int fd, __u32 *id)
{
        /* from an open block device, try to retrieve it scsi_id */
        struct stat st;
        char path[256];
        DIR *dir;
        struct dirent *de;
        int host, bus, target, lun;

        if (fstat(fd, &st))
                return 1;

        snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device/scsi_device",
                 major(st.st_rdev), minor(st.st_rdev));

        dir = opendir(path);
        if (!dir)
                return 1;

        for (de = readdir(dir); de; de = readdir(dir)) {
                int count;

                if (de->d_type != DT_DIR)
                        continue;

                count = sscanf(de->d_name, "%d:%d:%d:%d", &host, &bus, &target, &lun);
                if (count == 4)
                        break;
        }
        closedir(dir);

        if (!de)
                return 1;

        *id = (host << 24) | (bus << 16) | (target << 8) | (lun << 0);
        return 0;
}

int sysfs_unique_holder(char *devnm, long rdev)
{
        /* Check that devnm is a holder of rdev,
         * and is the only holder.
         * we should be locked against races by
         * an O_EXCL on devnm
         * Return values:
         *  0 - not unique, not even a holder
         *  1 - unique, this is the only holder.
         *  2/3 - not unique, there is another holder
         * -1 - error, cannot find the holders
         */
        DIR *dir;
        struct dirent *de;
        char dirname[100];
        char l;
        int ret = 0;
        sprintf(dirname, "/sys/dev/block/%d:%d/holders",
                major(rdev), minor(rdev));
        dir = opendir(dirname);
        if (!dir)
                return -1;
        l = strlen(dirname);
        while ((de = readdir(dir)) != NULL) {
                char buf[100];
                char *sl;
                int n;

                if (de->d_ino == 0)
                        continue;
                if (de->d_name[0] == '.')
                        continue;
                strcpy(dirname+l, "/");
                strcat(dirname+l, de->d_name);
                n = readlink(dirname, buf, sizeof(buf)-1);
                if (n <= 0)
                        continue;
                buf[n] = 0;
                sl = strrchr(buf, '/');
                if (!sl)
                        continue;
                sl++;

                if (strcmp(devnm, sl) == 0)
                        ret |= 1;
                else
                        ret |= 2;
        }
        closedir(dir);
        return ret;
}

int sysfs_freeze_array(struct mdinfo *sra)
{
        /* Try to freeze resync/rebuild on this array/container.
         * Return -1 if the array is busy,
         * return 0 if this kernel doesn't support 'frozen'
         * return 1 if it worked.
         */
        char buf[SYSFS_MAX_BUF_SIZE];

        if (!sysfs_attribute_available(sra, NULL, "sync_action"))
                return 1; /* no sync_action == frozen */
        if (sysfs_get_str(sra, NULL, "sync_action", buf, sizeof(buf)) <= 0)
                return 0;
        if (strcmp(buf, "frozen\n") == 0)
                /* Already frozen */
                return 0;
        if (strcmp(buf, "idle\n") != 0 && strcmp(buf, "recover\n") != 0)
                return -1;
        if (sysfs_set_str(sra, NULL, "sync_action", "frozen") < 0)
                return 0;
        return 1;
}

int sysfs_wait(int fd, int *msec)
{
        /* Wait up to '*msec' for fd to have an exception condition.
         * if msec == NULL, wait indefinitely.
         */
        fd_set fds;
        int n;
        FD_ZERO(&fds);
        FD_SET(fd, &fds);
        if (msec == NULL)
                n = select(fd+1, NULL, NULL, &fds, NULL);
        else if (*msec < 0)
                n = 0;
        else {
                struct timeval start, end, tv;
                gettimeofday(&start, NULL);
                if (*msec < 1000) {
                        tv.tv_sec = 0;
                        tv.tv_usec = (*msec)*1000;
                } else {
                        tv.tv_sec = (*msec)/1000;
                        tv.tv_usec = 0;
                }
                n = select(fd+1, NULL, NULL, &fds, &tv);
                gettimeofday(&end, NULL);
                end.tv_sec -= start.tv_sec;
                *msec -= (end.tv_sec * 1000 + end.tv_usec/1000
                          - start.tv_usec/1000) + 1;
        }
        return n;
}

int sysfs_rules_apply_check(const struct mdinfo *sra,
                            const struct sysfs_entry *ent)
{
        /* Check whether parameter is regular file,
         * exists and is under specified directory.
         */
        char fname[MAX_SYSFS_PATH_LEN];
        char dname[MAX_SYSFS_PATH_LEN];
        char resolved_path[PATH_MAX];
        char resolved_dir[PATH_MAX];
        int result;

        if (sra == NULL || ent == NULL)
                return -1;

        result = snprintf(dname, MAX_SYSFS_PATH_LEN,
                          "/sys/block/%s/md/", sra->sys_name);
        if (result < 0 || result >= MAX_SYSFS_PATH_LEN)
                return -1;

        result = snprintf(fname, MAX_SYSFS_PATH_LEN,
                          "%s/%s", dname, ent->name);
        if (result < 0 || result >= MAX_SYSFS_PATH_LEN)
                return -1;

        if (realpath(fname, resolved_path) == NULL ||
            realpath(dname, resolved_dir) == NULL)
                return -1;

        if (strncmp(resolved_dir, resolved_path,
                    strnlen(resolved_dir, PATH_MAX)) != 0)
                return -1;

        return 0;
}

static struct dev_sysfs_rule *sysfs_rules;

void sysfs_rules_apply(char *devnm, struct mdinfo *dev)
{
        struct dev_sysfs_rule *rules = sysfs_rules;

        while (rules) {
                struct sysfs_entry *ent = rules->entry;
                int match  = 0;

                if (!rules->uuid_set) {
                        if (rules->devname)
                                match = strcmp(devnm, rules->devname) == 0;
                } else {
                        match = memcmp(dev->uuid, rules->uuid,
                                       sizeof(int[4])) == 0;
                }

                while (match && ent) {
                        if (sysfs_rules_apply_check(dev, ent) < 0)
                                pr_err("SYSFS: failed to write '%s' to '%s'\n",
                                        ent->value, ent->name);
                        else
                                sysfs_set_str(dev, NULL, ent->name, ent->value);
                        ent = ent->next;
                }
                rules = rules->next;
        }
}

static void sysfs_rule_free(struct dev_sysfs_rule *rule)
{
        struct sysfs_entry *entry;

        while (rule) {
                struct dev_sysfs_rule *tmp = rule->next;

                entry = rule->entry;
                while (entry) {
                        struct sysfs_entry *tmp = entry->next;

                        free(entry->name);
                        free(entry->value);
                        free(entry);
                        entry = tmp;
                }

                if (rule->devname)
                        free(rule->devname);
                free(rule);
                rule = tmp;
        }
}

void sysfsline(char *line)
{
        struct dev_sysfs_rule *sr;
        char *w;

        sr = xcalloc(1, sizeof(*sr));
        for (w = dl_next(line); w != line ; w = dl_next(w)) {
                if (strncasecmp(w, "name=", 5) == 0) {
                        char *devname = w + 5;

                        if (strncmp(devname, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0) {
                                if (sr->devname)
                                        pr_err("Only give one device per SYSFS line: %s\n",
                                                devname);
                                else
                                        sr->devname = xstrdup(devname);
                        } else {
                                pr_err("%s is an invalid name for an md device - ignored.\n",
                                       devname);
                        }
                } else if (strncasecmp(w, "uuid=", 5) == 0) {
                        char *uuid = w + 5;

                        if (sr->uuid_set) {
                                pr_err("Only give one uuid per SYSFS line: %s\n",
                                        uuid);
                        } else {
                                if (parse_uuid(w + 5, sr->uuid) &&
                                    memcmp(sr->uuid, uuid_zero,
                                           sizeof(int[4])) != 0)
                                        sr->uuid_set = 1;
                                else
                                        pr_err("Invalid uuid: %s\n", uuid);
                        }
                } else {
                        struct sysfs_entry *prop;

                        char *sep = strchr(w, '=');

                        if (sep == NULL || *(sep + 1) == 0) {
                                pr_err("Cannot parse \"%s\" - ignoring.\n", w);
                                continue;
                        }

                        prop = xmalloc(sizeof(*prop));
                        prop->value = xstrdup(sep + 1);
                        *sep = 0;
                        prop->name = xstrdup(w);
                        prop->next = sr->entry;
                        sr->entry = prop;
                }
        }

        if (!sr->devname && !sr->uuid_set) {
                pr_err("Device name not found in sysfs config entry - ignoring.\n");
                sysfs_rule_free(sr);
                return;
        }

        sr->next = sysfs_rules;
        sysfs_rules = sr;
}

/**
 * sysfs_is_libata_allow_tpm_enabled() - check if libata allow_tmp is enabled.
 * @verbose: verbose flag.
 *
 * Check if libata allow_tmp flag is set, this is required for SATA Opal Security commands to work.
 *
 * Return: true if allow_tpm enable, false otherwise.
 */
bool sysfs_is_libata_allow_tpm_enabled(const int verbose)
{
        const char *path = "/sys/module/libata/parameters/allow_tpm";
        const char *expected_value = "1";
        int fd = open(path, O_RDONLY);
        char buf[3];

        if (!is_fd_valid(fd)) {
                pr_vrb("Failed open file descriptor to %s. Cannot check libata allow_tpm param.\n",
                       path);
                return false;
        }

        sysfs_fd_get_str(fd, buf, sizeof(buf));
        close(fd);

        if (strncmp(buf, expected_value, 1) == 0)
                return true;
        return false;
}