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         },
  82     },
  83     {
  84         .name = "synth",
  85         .ops = &synth_ops,
  86         .opts = (const char * []) {
  87             COMMON_FS_DRIVER_OPTIONS,
  88         },
  89     },
  90     {
  91         .name = "proxy",
  92         .ops = &proxy_ops,
  93         .opts = (const char * []) {
  94             COMMON_FS_DRIVER_OPTIONS,
  95             "socket",
  96             "sock_fd",
  97             "writeout",
  98         },
  99     },
 100 };
 101
 102 static int validate_opt(void *opaque, const char *name, const char *value,
 103                         Error **errp)
 104 {
 105     FsDriverTable *drv = opaque;
 106     const char **opt;
 107
 108     for (opt = drv->opts; *opt; opt++) {
 109         if (!strcmp(*opt, name)) {
 110             return 0;
 111         }
 112     }
 113
 114     error_setg(errp, "'%s' is invalid for fsdriver '%s'", name, drv->name);
 115     return -1;
 116 }
 117
 118 int qemu_fsdev_add(QemuOpts *opts, Error **errp)
 119 {
 120     int i;
 121     struct FsDriverListEntry *fsle;
 122     const char *fsdev_id = qemu_opts_id(opts);
 123     const char *fsdriver = qemu_opt_get(opts, "fsdriver");
 124     const char *writeout = qemu_opt_get(opts, "writeout");
 125     bool ro = qemu_opt_get_bool(opts, "readonly", 0);
 126
 127     if (!fsdev_id) {
 128         error_setg(errp, "fsdev: No id specified");
 129         return -1;
 130     }
 131
 132     if (fsdriver) {
 133         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
 134             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
 135                 break;
 136             }
 137         }
 138
 139         if (i == ARRAY_SIZE(FsDrivers)) {
 140             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
 141             return -1;
 142         }
 143     } else {
 144         error_setg(errp, "fsdev: No fsdriver specified");
 145         return -1;
 146     }
 147
 148     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
 149         return -1;
 150     }
 151
 152     fsle = g_malloc0(sizeof(*fsle));
 153     fsle->fse.fsdev_id = g_strdup(fsdev_id);
 154     fsle->fse.ops = FsDrivers[i].ops;
 155     if (writeout) {
 156         if (!strcmp(writeout, "immediate")) {
 157             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
 158         }
 159     }
 160     if (ro) {
 161         fsle->fse.export_flags |= V9FS_RDONLY;
 162     } else {
 163         fsle->fse.export_flags &= ~V9FS_RDONLY;
 164     }
 165
 166     if (fsle->fse.ops->parse_opts) {
 167         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
 168             g_free(fsle->fse.fsdev_id);
 169             g_free(fsle);
 170             return -1;
 171         }
 172     }
 173
 174     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
 175     return 0;
 176 }
 177
 178 FsDriverEntry *get_fsdev_fsentry(char *id)
 179 {
 180     if (id) {
 181         struct FsDriverListEntry *fsle;
 182
 183         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
 184             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
 185                 return &fsle->fse;
 186             }
 187         }
 188     }
 189     return NULL;
 190 }