LXR qemu/fsdev/qemu-fsdev.c

   1/*
   2 * 9p
   3 *
   4 * Copyright IBM, Corp. 2010
   5 *
   6 * Authors:
   7 *  Gautham R Shenoy <ego@in.ibm.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 */
  12
  13#include "qemu/osdep.h"
  14#include "qapi/error.h"
  15#include "qemu-fsdev.h"
  16#include "qemu/queue.h"
  17#include "qemu/config-file.h"
  18#include "qemu/error-report.h"
  19#include "qemu/option.h"
  20
  21/*
  22 * A table to store the various file systems and their callback operations.
  23 * -----------------
  24 * fstype | ops
  25 * -----------------
  26 *  local | local_ops
  27 *  .     |
  28 *  .     |
  29 *  .     |
  30 *  .     |
  31 * -----------------
  32 *  etc
  33 */
  34typedef struct FsDriverTable {
  35    const char *name;
  36    FileOperations *ops;
  37    const char **opts;
  38} FsDriverTable;
  39
  40typedef struct FsDriverListEntry {
  41    FsDriverEntry fse;
  42    QTAILQ_ENTRY(FsDriverListEntry) next;
  43} FsDriverListEntry;
  44
  45static QTAILQ_HEAD(, FsDriverListEntry) fsdriver_entries =
  46    QTAILQ_HEAD_INITIALIZER(fsdriver_entries);
  47
  48#define COMMON_FS_DRIVER_OPTIONS "id", "fsdriver", "readonly"
  49
  50static FsDriverTable FsDrivers[] = {
  51    {
  52        .name = "local",
  53        .ops = &local_ops,
  54        .opts = (const char * []) {
  55            COMMON_FS_DRIVER_OPTIONS,
  56            "security_model",
  57            "path",
  58            "writeout",
  59            "fmode",
  60            "dmode",
  61            "multidevs",
  62            "throttling.bps-total",
  63            "throttling.bps-read",
  64            "throttling.bps-write",
  65            "throttling.iops-total",
  66            "throttling.iops-read",
  67            "throttling.iops-write",
  68            "throttling.bps-total-max",
  69            "throttling.bps-read-max",
  70            "throttling.bps-write-max",
  71            "throttling.iops-total-max",
  72            "throttling.iops-read-max",
  73            "throttling.iops-write-max",
  74            "throttling.bps-total-max-length",
  75            "throttling.bps-read-max-length",
  76            "throttling.bps-write-max-length",
  77            "throttling.iops-total-max-length",
  78            "throttling.iops-read-max-length",
  79            "throttling.iops-write-max-length",
  80            "throttling.iops-size",
  81            NULL
  82        },
  83    },
  84    {
  85        .name = "synth",
  86        .ops = &synth_ops,
  87        .opts = (const char * []) {
  88            COMMON_FS_DRIVER_OPTIONS,
  89            NULL
  90        },
  91    },
  92    {
  93        .name = "proxy",
  94        .ops = &proxy_ops,
  95        .opts = (const char * []) {
  96            COMMON_FS_DRIVER_OPTIONS,
  97            "socket",
  98            "sock_fd",
  99            "writeout",
 100            NULL
 101        },
 102    },
 103};
 104
 105static int validate_opt(void *opaque, const char *name, const char *value,
 106                        Error **errp)
 107{
 108    FsDriverTable *drv = opaque;
 109    const char **opt;
 110
 111    for (opt = drv->opts; *opt; opt++) {
 112        if (!strcmp(*opt, name)) {
 113            return 0;
 114        }
 115    }
 116
 117    error_setg(errp, "'%s' is invalid for fsdriver '%s'", name, drv->name);
 118    return -1;
 119}
 120
 121int qemu_fsdev_add(QemuOpts *opts, Error **errp)
 122{
 123    int i;
 124    struct FsDriverListEntry *fsle;
 125    const char *fsdev_id = qemu_opts_id(opts);
 126    const char *fsdriver = qemu_opt_get(opts, "fsdriver");
 127    const char *writeout = qemu_opt_get(opts, "writeout");
 128    bool ro = qemu_opt_get_bool(opts, "readonly", 0);
 129
 130    if (!fsdev_id) {
 131        error_setg(errp, "fsdev: No id specified");
 132        return -1;
 133    }
 134
 135    if (fsdriver) {
 136        for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
 137            if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
 138                break;
 139            }
 140        }
 141
 142        if (i == ARRAY_SIZE(FsDrivers)) {
 143            error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
 144            return -1;
 145        }
 146    } else {
 147        error_setg(errp, "fsdev: No fsdriver specified");
 148        return -1;
 149    }
 150
 151    if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
 152        return -1;
 153    }
 154
 155    fsle = g_malloc0(sizeof(*fsle));
 156    fsle->fse.fsdev_id = g_strdup(fsdev_id);
 157    fsle->fse.ops = FsDrivers[i].ops;
 158    if (writeout) {
 159        if (!strcmp(writeout, "immediate")) {
 160            fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
 161        }
 162    }
 163    if (ro) {
 164        fsle->fse.export_flags |= V9FS_RDONLY;
 165    } else {
 166        fsle->fse.export_flags &= ~V9FS_RDONLY;
 167    }
 168
 169    if (fsle->fse.ops->parse_opts) {
 170        if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
 171            g_free(fsle->fse.fsdev_id);
 172            g_free(fsle);
 173            return -1;
 174        }
 175    }
 176
 177    QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
 178    return 0;
 179}
 180
 181FsDriverEntry *get_fsdev_fsentry(char *id)
 182{
 183    if (id) {
 184        struct FsDriverListEntry *fsle;
 185
 186        QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
 187            if (strcmp(fsle->fse.fsdev_id, id) == 0) {
 188                return &fsle->fse;
 189            }
 190        }
 191    }
 192    return NULL;
 193}
 194