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             "throttling.bps-total",
  62             "throttling.bps-read",
  63             "throttling.bps-write",
  64             "throttling.iops-total",
  65             "throttling.iops-read",
  66             "throttling.iops-write",
  67             "throttling.bps-total-max",
  68             "throttling.bps-read-max",
  69             "throttling.bps-write-max",
  70             "throttling.iops-total-max",
  71             "throttling.iops-read-max",
  72             "throttling.iops-write-max",
  73             "throttling.bps-total-max-length",
  74             "throttling.bps-read-max-length",
  75             "throttling.bps-write-max-length",
  76             "throttling.iops-total-max-length",
  77             "throttling.iops-read-max-length",
  78             "throttling.iops-write-max-length",
  79             "throttling.iops-size",
  80         },
  81     },
  82     {
  83         .name = "synth",
  84         .ops = &synth_ops,
  85         .opts = (const char * []) {
  86             COMMON_FS_DRIVER_OPTIONS,
  87         },
  88     },
  89     {
  90         .name = "proxy",
  91         .ops = &proxy_ops,
  92         .opts = (const char * []) {
  93             COMMON_FS_DRIVER_OPTIONS,
  94             "socket",
  95             "sock_fd",
  96             "writeout",
  97         },
  98     },
  99 };
 100
 101 static int validate_opt(void *opaque, const char *name, const char *value,
 102                         Error **errp)
 103 {
 104     FsDriverTable *drv = opaque;
 105     const char **opt;
 106
 107     for (opt = drv->opts; *opt; opt++) {
 108         if (!strcmp(*opt, name)) {
 109             return 0;
 110         }
 111     }
 112
 113     error_setg(errp, "'%s' is invalid for fsdriver '%s'", name, drv->name);
 114     return -1;
 115 }
 116
 117 int qemu_fsdev_add(QemuOpts *opts, Error **errp)
 118 {
 119     int i;
 120     struct FsDriverListEntry *fsle;
 121     const char *fsdev_id = qemu_opts_id(opts);
 122     const char *fsdriver = qemu_opt_get(opts, "fsdriver");
 123     const char *writeout = qemu_opt_get(opts, "writeout");
 124     bool ro = qemu_opt_get_bool(opts, "readonly", 0);
 125
 126     if (!fsdev_id) {
 127         error_setg(errp, "fsdev: No id specified");
 128         return -1;
 129     }
 130
 131     if (fsdriver) {
 132         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
 133             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
 134                 break;
 135             }
 136         }
 137
 138         if (i == ARRAY_SIZE(FsDrivers)) {
 139             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
 140             return -1;
 141         }
 142     } else {
 143         error_setg(errp, "fsdev: No fsdriver specified");
 144         return -1;
 145     }
 146
 147     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
 148         return -1;
 149     }
 150
 151     fsle = g_malloc0(sizeof(*fsle));
 152     fsle->fse.fsdev_id = g_strdup(fsdev_id);
 153     fsle->fse.ops = FsDrivers[i].ops;
 154     if (writeout) {
 155         if (!strcmp(writeout, "immediate")) {
 156             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
 157         }
 158     }
 159     if (ro) {
 160         fsle->fse.export_flags |= V9FS_RDONLY;
 161     } else {
 162         fsle->fse.export_flags &= ~V9FS_RDONLY;
 163     }
 164
 165     if (fsle->fse.ops->parse_opts) {
 166         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
 167             g_free(fsle->fse.fsdev_id);
 168             g_free(fsle);
 169             return -1;
 170         }
 171     }
 172
 173     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
 174     return 0;
 175 }
 176
 177 FsDriverEntry *get_fsdev_fsentry(char *id)
 178 {
 179     if (id) {
 180         struct FsDriverListEntry *fsle;
 181
 182         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
 183             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
 184                 return &fsle->fse;
 185             }
 186         }
 187     }
 188     return NULL;
 189 }