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         .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
 105 static 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
 121 int 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         if (strncmp(fsdriver, "proxy", 5) == 0) {
 137             warn_report(
 138                 "'-fsdev proxy' and '-virtfs proxy' are deprecated, use "
 139                 "'local' instead of 'proxy, or consider deploying virtiofsd "
 140                 "as alternative to 9p"
 141             );
 142         }
 143
 144         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
 145             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
 146                 break;
 147             }
 148         }
 149
 150         if (i == ARRAY_SIZE(FsDrivers)) {
 151             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
 152             return -1;
 153         }
 154     } else {
 155         error_setg(errp, "fsdev: No fsdriver specified");
 156         return -1;
 157     }
 158
 159     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
 160         return -1;
 161     }
 162
 163     fsle = g_malloc0(sizeof(*fsle));
 164     fsle->fse.fsdev_id = g_strdup(fsdev_id);
 165     fsle->fse.ops = FsDrivers[i].ops;
 166     if (writeout) {
 167         if (!strcmp(writeout, "immediate")) {
 168             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
 169         }
 170     }
 171     if (ro) {
 172         fsle->fse.export_flags |= V9FS_RDONLY;
 173     } else {
 174         fsle->fse.export_flags &= ~V9FS_RDONLY;
 175     }
 176
 177     if (fsle->fse.ops->parse_opts) {
 178         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
 179             g_free(fsle->fse.fsdev_id);
 180             g_free(fsle);
 181             return -1;
 182         }
 183     }
 184
 185     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
 186     return 0;
 187 }
 188
 189 FsDriverEntry *get_fsdev_fsentry(char *id)
 190 {
 191     if (id) {
 192         struct FsDriverListEntry *fsle;
 193
 194         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
 195             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
 196                 return &fsle->fse;
 197             }
 198         }
 199     }
 200     return NULL;
 201 }