xref: /openbmc/qemu/fsdev/qemu-fsdev.c (revision e6e03dcf)
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 }
191