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  */
  34 typedef struct FsDriverTable {
  35     const char *name;
  36     FileOperations *ops;
  37     const char **opts;
  38 } FsDriverTable;
  39
  40 typedef struct FsDriverListEntry {
  41     FsDriverEntry fse;
  42     QTAILQ_ENTRY(FsDriverListEntry) next;
  43 } FsDriverListEntry;
  44
  45 static QTAILQ_HEAD(, FsDriverListEntry) fsdriver_entries =
  46     QTAILQ_HEAD_INITIALIZER(fsdriver_entries);
  47
  48 #define COMMON_FS_DRIVER_OPTIONS "id", "fsdriver", "readonly"
  49
  50 static 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
  94 static int validate_opt(void *opaque, const char *name, const char *value,
  95                         Error **errp)
  96 {
  97     FsDriverTable *drv = opaque;
  98     const char **opt;
  99
 100     for (opt = drv->opts; *opt; opt++) {
 101         if (!strcmp(*opt, name)) {
 102             return 0;
 103         }
 104     }
 105
 106     error_setg(errp, "'%s' is invalid for fsdriver '%s'", name, drv->name);
 107     return -1;
 108 }
 109
 110 int qemu_fsdev_add(QemuOpts *opts, Error **errp)
 111 {
 112     int i;
 113     struct FsDriverListEntry *fsle;
 114     const char *fsdev_id = qemu_opts_id(opts);
 115     const char *fsdriver = qemu_opt_get(opts, "fsdriver");
 116     const char *writeout = qemu_opt_get(opts, "writeout");
 117     bool ro = qemu_opt_get_bool(opts, "readonly", 0);
 118
 119     if (!fsdev_id) {
 120         error_setg(errp, "fsdev: No id specified");
 121         return -1;
 122     }
 123
 124     if (fsdriver) {
 125         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
 126             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
 127                 break;
 128             }
 129         }
 130
 131         if (i == ARRAY_SIZE(FsDrivers)) {
 132             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
 133             return -1;
 134         }
 135     } else {
 136         error_setg(errp, "fsdev: No fsdriver specified");
 137         return -1;
 138     }
 139
 140     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
 141         return -1;
 142     }
 143
 144     fsle = g_malloc0(sizeof(*fsle));
 145     fsle->fse.fsdev_id = g_strdup(fsdev_id);
 146     fsle->fse.ops = FsDrivers[i].ops;
 147     if (writeout) {
 148         if (!strcmp(writeout, "immediate")) {
 149             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
 150         }
 151     }
 152     if (ro) {
 153         fsle->fse.export_flags |= V9FS_RDONLY;
 154     } else {
 155         fsle->fse.export_flags &= ~V9FS_RDONLY;
 156     }
 157
 158     if (fsle->fse.ops->parse_opts) {
 159         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
 160             g_free(fsle->fse.fsdev_id);
 161             g_free(fsle);
 162             return -1;
 163         }
 164     }
 165
 166     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
 167     return 0;
 168 }
 169
 170 FsDriverEntry *get_fsdev_fsentry(char *id)
 171 {
 172     if (id) {
 173         struct FsDriverListEntry *fsle;
 174
 175         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
 176             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
 177                 return &fsle->fse;
 178             }
 179         }
 180     }
 181     return NULL;
 182 }