source: mainline/uspace/srv/volsrv/part.c@ ca127f37

/*
 * Copyright (c) 2024 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup volsrv
 * @{
 */
/**
 * @file Partition handling
 * @brief
 */

#include <adt/list.h>
#include <errno.h>
#include <fibril_synch.h>
#include <io/log.h>
#include <loc.h>
#include <stdbool.h>
#include <stdlib.h>
#include <str.h>
#include <str_error.h>
#include <vfs/vfs.h>
#include <vol.h>

#include "empty.h"
#include "mkfs.h"
#include "part.h"
#include "types/part.h"
#include "volume.h"
#include "volsrv.h"

static errno_t vol_part_add_locked(vol_parts_t *, service_id_t);
static void vol_part_remove_locked(vol_part_t *);
static errno_t vol_part_find_by_id_ref_locked(vol_parts_t *, service_id_t,
    vol_part_t **);

struct fsname_type {
        const char *name;
        vol_fstype_t fstype;
};

static struct fsname_type fstab[] = {
        { "ext4fs", fs_ext4 },
        { "cdfs", fs_cdfs },
        { "exfat", fs_exfat },
        { "fat", fs_fat },
        { "mfs", fs_minix },
        { NULL, 0 }
};

static const char *fstype_str(vol_fstype_t fstype)
{
        struct fsname_type *fst;

        fst = &fstab[0];
        while (fst->name != NULL) {
                if (fst->fstype == fstype)
                        return fst->name;
                ++fst;
        }

        assert(false);
        return NULL;
}

/** Check for new and removed partitions */
static errno_t vol_part_check_new(vol_parts_t *parts)
{
        bool already_known;
        bool still_exists;
        category_id_t part_cat;
        service_id_t *svcs;
        size_t count, i;
        link_t *cur, *next;
        vol_part_t *part;
        errno_t rc;

        fibril_mutex_lock(&parts->lock);

        rc = loc_category_get_id("partition", &part_cat, IPC_FLAG_BLOCKING);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed resolving category 'partition'.");
                fibril_mutex_unlock(&parts->lock);
                return ENOENT;
        }

        rc = loc_category_get_svcs(part_cat, &svcs, &count);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed getting list of partition "
                    "devices.");
                fibril_mutex_unlock(&parts->lock);
                return EIO;
        }

        /* Check for new partitions */
        for (i = 0; i < count; i++) {
                already_known = false;

                // XXX Make this faster
                list_foreach(parts->parts, lparts, vol_part_t, part) {
                        if (part->svc_id == svcs[i]) {
                                already_known = true;
                                break;
                        }
                }

                if (!already_known) {
                        log_msg(LOG_DEFAULT, LVL_DEBUG, "Found partition '%lu'",
                            (unsigned long) svcs[i]);
                        rc = vol_part_add_locked(parts, svcs[i]);
                        if (rc != EOK) {
                                log_msg(LOG_DEFAULT, LVL_ERROR, "Could not add "
                                    "partition.");
                        }
                }
        }

        /* Check for removed partitions */
        cur = list_first(&parts->parts);
        while (cur != NULL) {
                next = list_next(cur, &parts->parts);
                part = list_get_instance(cur, vol_part_t, lparts);

                still_exists = false;
                // XXX Make this faster
                for (i = 0; i < count; i++) {
                        if (part->svc_id == svcs[i]) {
                                still_exists = true;
                                break;
                        }
                }

                if (!still_exists) {
                        log_msg(LOG_DEFAULT, LVL_DEBUG, "Partition '%zu' is gone",
                            part->svc_id);
                        vol_part_remove_locked(part);
                }

                cur = next;
        }

        free(svcs);

        fibril_mutex_unlock(&parts->lock);
        return EOK;
}

static vol_part_t *vol_part_new(void)
{
        vol_part_t *part = calloc(1, sizeof(vol_part_t));

        if (part == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed allocating partition "
                    "structure. Out of memory.");
                return NULL;
        }

        refcount_init(&part->refcnt);
        link_initialize(&part->lparts);
        part->parts = NULL;
        part->pcnt = vpc_empty;

        return part;
}

static void vol_part_delete(vol_part_t *part)
{
        log_msg(LOG_DEFAULT, LVL_ERROR, "Freeing partition %p", part);
        if (part == NULL)
                return;

        if (part->volume != NULL)
                vol_volume_del_ref(part->volume);

        free(part->cur_mp);
        free(part->svc_name);
        free(part);
}

static errno_t vol_part_probe(vol_part_t *part)
{
        bool empty;
        vfs_fs_probe_info_t info;
        struct fsname_type *fst;
        char *label;
        vol_volume_t *volume;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Probe partition %s", part->svc_name);

        assert(fibril_mutex_is_locked(&part->parts->lock));

        fst = &fstab[0];
        while (fst->name != NULL) {
                rc = vfs_fsprobe(fst->name, part->svc_id, &info);
                if (rc == EOK)
                        break;
                ++fst;
        }

        if (fst->name != NULL) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Found %s, label '%s'",
                    fst->name, info.label);
                label = str_dup(info.label);
                if (label == NULL) {
                        rc = ENOMEM;
                        goto error;
                }

                part->pcnt = vpc_fs;
                part->fstype = fst->fstype;
                part->label = label;
        } else {
                log_msg(LOG_DEFAULT, LVL_NOTE, "Partition does not contain "
                    "a recognized file system.");

                rc = volsrv_part_is_empty(part->svc_id, &empty);
                if (rc != EOK) {
                        log_msg(LOG_DEFAULT, LVL_ERROR, "Failed determining if "
                            "partition is empty.");
                        rc = EIO;
                        goto error;
                }

                label = str_dup("");
                if (label == NULL) {
                        rc = ENOMEM;
                        goto error;
                }

                part->pcnt = empty ? vpc_empty : vpc_unknown;
                part->label = label;
        }

        /* Look up new or existing volume. */
        rc = vol_volume_lookup_ref(part->parts->volumes, part->label, &volume);
        if (rc != EOK)
                goto error;

        part->volume = volume;
        return EOK;

error:
        return rc;
}

/** Determine if partition is allowed to be mounted by default.
 *
 * @param part Partition
 * @return @c true iff partition is allowed to be mounted by default
 */
static bool vol_part_allow_mount_by_def(vol_part_t *part)
{
        /* CDFS is safe to mount (after all, it is read-only) */
        if (part->pcnt == vpc_fs && part->fstype == fs_cdfs)
                return true;

        /* For other file systems disallow mounting from ATA hard drive */
        if (str_str(part->svc_name, "\\ata-c") != NULL)
                return false;

        /* Allow otherwise (e.g. USB mass storage) */
        return true;
}

/** Determine the default mount point for a partition.
 *
 * @param part Partition
 * @return Pointer to the constant string "Auto" or "None"
 */
static const char *vol_part_def_mountp(vol_part_t *part)
{
        return vol_part_allow_mount_by_def(part) ? "Auto" : "None";
}

/** Determine actual mount path to be used for a partition.
 *
 * @param part Partition
 * @param rpath Place to store pointer to newly allocated string or @c NULL
 *              if volume should not be mounted
 * @param rauto Place to store boolean flag whether mount point is automatic
 *
 * @return EOK on success, ENOMEM if out of memory
 */
static errno_t vol_part_determine_mount_path(vol_part_t *part, char **rpath,
    bool *rauto)
{
        const char *cfg_mp;
        char *mp;
        bool mp_auto;
        int err;

        /* Get configured mount point */
        if (str_size(part->volume->mountp) > 0) {
                cfg_mp = part->volume->mountp;
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Configured mount point '%s'",
                    cfg_mp);
        } else {
                cfg_mp = vol_part_def_mountp(part);
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Default mount point '%s'",
                    cfg_mp);
        }

        if (str_cmp(cfg_mp, "Auto") == 0 || str_cmp(cfg_mp, "auto") == 0) {

                if (str_size(part->label) < 1) {
                        /* Don't mount nameless volumes */
                        *rpath = NULL;
                        *rauto = false;
                        return EOK;
                }

                log_msg(LOG_DEFAULT, LVL_DEBUG, "Determine MP label='%s'", part->label);
                err = asprintf(&mp, "/vol/%s", part->label);
                if (err < 0) {
                        log_msg(LOG_DEFAULT, LVL_ERROR, "Out of memory");
                        return ENOMEM;
                }

                mp_auto = true;
        } else if (str_cmp(cfg_mp, "None") == 0 || str_cmp(cfg_mp, "none") == 0) {
                mp = NULL;
                mp_auto = false;
        } else {
                mp = str_dup(cfg_mp);
                mp_auto = false;
        }

        *rpath = mp;
        *rauto = mp_auto;
        return EOK;
}

/** Mount partition.
 *
 * @param part Partition
 */
static errno_t vol_part_mount(vol_part_t *part)
{
        char *mp;
        bool mp_auto;
        errno_t rc;

        rc = vol_part_determine_mount_path(part, &mp, &mp_auto);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Error determining mount point.\n");
                return rc;
        }

        if (mp == NULL) {
                log_msg(LOG_DEFAULT, LVL_NOTE, "Not mounting volume.");
                return EOK;
        }

        if (mp_auto) {
                /* Create directory for automatic mount point */
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Create mount point '%s'", mp);
                rc = vfs_link_path(mp, KIND_DIRECTORY, NULL);
                if (rc != EOK) {
                        log_msg(LOG_DEFAULT, LVL_ERROR, "Error creating mount point '%s'",
                            mp);
                        free(mp);
                        return EIO;
                }
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Call vfs_mount_path mp='%s' fstype='%s' svc_name='%s'",
            mp, fstype_str(part->fstype), part->svc_name);
        rc = vfs_mount_path(mp, fstype_str(part->fstype),
            part->svc_name, "", 0, 0);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed mounting %s at %s to %s",
                    fstype_str(part->fstype), part->svc_name, mp);
        } else {
                log_msg(LOG_DEFAULT, LVL_NOTE, "Mounted %s at %s to %s\n",
                    fstype_str(part->fstype), part->svc_name, mp);
        }

        part->cur_mp = mp;
        part->cur_mp_auto = mp_auto;

        if (str_cmp(mp, "/w") == 0) {
                log_msg(LOG_DEFAULT, LVL_NOTE, "Mounted system volume - "
                    "loading additional configuration.");
                rc = vol_volumes_merge_to(part->parts->volumes,
                    vol_cfg_file);
                if (rc != EOK) {
                        log_msg(LOG_DEFAULT, LVL_ERROR, "Error loading "
                            "additional configuration.");
                        return rc;
                }
        }

        return rc;
}

static errno_t vol_part_add_locked(vol_parts_t *parts, service_id_t sid)
{
        vol_part_t *part;
        errno_t rc;

        assert(fibril_mutex_is_locked(&parts->lock));
        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_add_locked(%zu)", sid);

        /* Check for duplicates */
        rc = vol_part_find_by_id_ref_locked(parts, sid, &part);
        if (rc == EOK) {
                vol_part_del_ref(part);
                return EEXIST;
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "partition %zu is new", sid);

        part = vol_part_new();
        if (part == NULL)
                return ENOMEM;

        part->svc_id = sid;
        part->parts = parts;

        rc = loc_service_get_name(sid, &part->svc_name);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed getting service name.");
                goto error;
        }

        rc = vol_part_probe(part);
        if (rc != EOK)
                goto error;

        rc = vol_part_mount(part);
        if (rc != EOK)
                goto error;

        list_append(&part->lparts, &parts->parts);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Added partition %zu", part->svc_id);

        return EOK;

error:
        vol_part_delete(part);
        return rc;
}

static void vol_part_remove_locked(vol_part_t *part)
{
        assert(fibril_mutex_is_locked(&part->parts->lock));
        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_remove_locked(%zu)",
            part->svc_id);

        list_remove(&part->lparts);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "Removed partition.");
        vol_part_del_ref(part);
}

errno_t vol_part_add_part(vol_parts_t *parts, service_id_t sid)
{
        errno_t rc;

        fibril_mutex_lock(&parts->lock);
        rc = vol_part_add_locked(parts, sid);
        fibril_mutex_unlock(&parts->lock);

        return rc;
}

static void vol_part_cat_change_cb(void *arg)
{
        vol_parts_t *parts = (vol_parts_t *) arg;

        (void) vol_part_check_new(parts);
}

errno_t vol_parts_create(vol_volumes_t *volumes, vol_parts_t **rparts)
{
        vol_parts_t *parts;

        parts = calloc(1, sizeof(vol_parts_t));
        if (parts == NULL)
                return ENOMEM;

        fibril_mutex_initialize(&parts->lock);
        list_initialize(&parts->parts);
        parts->volumes = volumes;

        *rparts = parts;
        return EOK;
}

void vol_parts_destroy(vol_parts_t *parts)
{
        if (parts == NULL)
                return;

        assert(list_empty(&parts->parts));
        free(parts);
}

errno_t vol_part_discovery_start(vol_parts_t *parts)
{
        errno_t rc;

        rc = loc_register_cat_change_cb(vol_part_cat_change_cb, parts);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering callback "
                    "for partition discovery: %s.", str_error(rc));
                return rc;
        }

        return vol_part_check_new(parts);
}

/** Get list of partitions as array of service IDs. */
errno_t vol_part_get_ids(vol_parts_t *parts, service_id_t *id_buf,
    size_t buf_size, size_t *act_size)
{
        size_t act_cnt;
        size_t buf_cnt;

        fibril_mutex_lock(&parts->lock);

        buf_cnt = buf_size / sizeof(service_id_t);

        act_cnt = list_count(&parts->parts);
        *act_size = act_cnt * sizeof(service_id_t);

        if (buf_size % sizeof(service_id_t) != 0) {
                fibril_mutex_unlock(&parts->lock);
                return EINVAL;
        }

        size_t pos = 0;
        list_foreach(parts->parts, lparts, vol_part_t, part) {
                if (pos < buf_cnt)
                        id_buf[pos] = part->svc_id;
                pos++;
        }

        fibril_mutex_unlock(&parts->lock);
        return EOK;
}

static errno_t vol_part_find_by_id_ref_locked(vol_parts_t *parts,
    service_id_t sid, vol_part_t **rpart)
{
        assert(fibril_mutex_is_locked(&parts->lock));

        list_foreach(parts->parts, lparts, vol_part_t, part) {
                if (part->svc_id == sid) {
                        /* Add reference */
                        refcount_up(&part->refcnt);
                        *rpart = part;
                        return EOK;
                }
        }

        return ENOENT;
}

errno_t vol_part_find_by_id_ref(vol_parts_t *parts, service_id_t sid,
    vol_part_t **rpart)
{
        errno_t rc;

        fibril_mutex_lock(&parts->lock);
        rc = vol_part_find_by_id_ref_locked(parts, sid, rpart);
        fibril_mutex_unlock(&parts->lock);

        return rc;
}

/** Find partition by filesystem path.
 *
 * @param parts Partitions
 * @param path Filesystem path
 * @param rpart Place to store pointer to partition
 * @return EOK on success, ENOENT if not found, ENOMEM if out of memory
 */
errno_t vol_part_find_by_path_ref(vol_parts_t *parts, const char *path,
    vol_part_t **rpart)
{
        errno_t rc;
        char *mpath;
        bool mauto;

        fibril_mutex_lock(&parts->lock);

        list_foreach(parts->parts, lparts, vol_part_t, part) {
                rc = vol_part_determine_mount_path(part, &mpath, &mauto);
                if (rc != EOK) {
                        fibril_mutex_unlock(&parts->lock);
                        return ENOMEM;
                }

                if (mpath != NULL && str_cmp(mpath, path) == 0) {
                        /* Add reference */
                        refcount_up(&part->refcnt);
                        fibril_mutex_unlock(&parts->lock);
                        free(mpath);
                        *rpart = part;
                        return EOK;
                }

                if (mpath != NULL)
                        free(mpath);
        }

        fibril_mutex_unlock(&parts->lock);
        return ENOENT;
}

void vol_part_del_ref(vol_part_t *part)
{
        if (refcount_down(&part->refcnt))
                vol_part_delete(part);
}

errno_t vol_part_eject_part(vol_part_t *part)
{
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_eject_part()");

        if (part->cur_mp == NULL) {
                /* Partition is not mounted, nothing to do. */
                log_msg(LOG_DEFAULT, LVL_DEBUG, "Partition not mounted, "
                    "nothing to do.");
                goto done;
        }

        rc = vfs_unmount_path(part->cur_mp);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed unmounting partition "
                    "from %s", part->cur_mp);
                return rc;
        }

        if (part->cur_mp_auto) {
                rc = vfs_unlink_path(part->cur_mp);
                if (rc != EOK) {
                        log_msg(LOG_DEFAULT, LVL_ERROR, "Failed deleting "
                            "mount directory %s.", part->cur_mp);
                }
        }

        free(part->cur_mp);
        part->cur_mp = NULL;
        part->cur_mp_auto = false;
done:
        return EOK;
}

errno_t vol_part_empty_part(vol_part_t *part)
{
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_empty_part()");

        rc = volsrv_part_empty(part->svc_id);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_empty_part() - failed %s",
                    str_error(rc));
                return rc;
        }

        part->pcnt = vpc_empty;
        return EOK;
}

/** Insert volume.
 *
 * Re-mount the volume in the partition, if applicable.
 *
 * @param part Partition
 */
errno_t vol_part_insert_part(vol_part_t *part)
{
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_insert_part()");

        fibril_mutex_lock(&part->parts->lock);

        if (part->cur_mp != NULL) {
                fibril_mutex_unlock(&part->parts->lock);
                return EOK;
        }

        rc = vol_part_probe(part);
        if (rc != EOK)
                goto error;

        rc = vol_part_mount(part);
        if (rc != EOK)
                goto error;

        fibril_mutex_unlock(&part->parts->lock);

        return EOK;
error:
        return rc;
}

/** Set mount point.
 *
 * Verify and set a mount point. If the value of the mount point is
 * the same as the default value, we will actually unset the mount point
 * value (therefore effectively changing it to use the default).
 *
 * @return EOK on success, error code otherwise
 */
static errno_t vol_part_mountp_set(vol_part_t *part, const char *mountp)
{
        errno_t rc;
        const char *def_mp;
        const char *mp;

        rc = vol_mountp_validate(mountp);
        if (rc != EOK)
                return rc;

        def_mp = vol_part_def_mountp(part);

        /* If the value is the same as default, set to empty string. */
        if (str_cmp(def_mp, mountp) == 0)
                mp = "";
        else
                mp = mountp;

        rc = vol_volume_set_mountp(part->volume, mp);
        if (rc != EOK)
                return rc;

        return EOK;
}

errno_t vol_part_mkfs_part(vol_part_t *part, vol_fstype_t fstype,
    const char *label, const char *mountp)
{
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_mkfs_part()");

        fibril_mutex_lock(&part->parts->lock);

        rc = volsrv_part_mkfs(part->svc_id, fstype, label);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "vol_part_mkfs_part() - failed %s",
                    str_error(rc));
                fibril_mutex_unlock(&part->parts->lock);
                return rc;
        }

        /*
         * Re-probe the partition to update information. This is needed since
         * the FS can make conversions of the volume label (e.g. make it
         * uppercase).
         */
        rc = vol_part_probe(part);
        if (rc != EOK) {
                fibril_mutex_unlock(&part->parts->lock);
                return rc;
        }

        rc = vol_part_mountp_set(part, mountp);
        if (rc != EOK) {
                fibril_mutex_unlock(&part->parts->lock);
                return rc;
        }

        rc = vol_part_mount(part);
        if (rc != EOK) {
                fibril_mutex_unlock(&part->parts->lock);
                return rc;
        }

        fibril_mutex_unlock(&part->parts->lock);
        return EOK;
}

/** Set partition mount point.
 *
 * Set the partition mount point, (un-, re-)mounting the partition as necessary.
 *
 * @param part Partition
 * @param mountp
 *
 * @return EOK on success or error code
 */
errno_t vol_part_set_mountp_part(vol_part_t *part, const char *mountp)
{
        errno_t rc;

        if (part->cur_mp != NULL) {
                rc = vol_part_eject_part(part);
                if (rc != EOK)
                        return rc;
        }

        rc = vol_part_mountp_set(part, mountp);
        if (rc != EOK)
                return rc;

        rc = vol_part_mount(part);
        if (rc != EOK)
                return rc;

        return EOK;
}

errno_t vol_part_get_info(vol_part_t *part, vol_part_info_t *pinfo)
{
        memset(pinfo, 0, sizeof(*pinfo));

        pinfo->pcnt = part->pcnt;
        pinfo->fstype = part->fstype;
        str_cpy(pinfo->label, sizeof(pinfo->label), part->label);
        if (part->cur_mp != NULL)
                str_cpy(pinfo->cur_mp, sizeof(pinfo->cur_mp), part->cur_mp);
        pinfo->cur_mp_auto = part->cur_mp_auto;
        return EOK;
}

/** @}
 */