xref: /openbmc/qemu/fsdev/qemu-fsdev.c (revision ffe98631)
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         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
137             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
138                 break;
139             }
140         }
141 
142         if (i == ARRAY_SIZE(FsDrivers)) {
143             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
144             return -1;
145         }
146     } else {
147         error_setg(errp, "fsdev: No fsdriver specified");
148         return -1;
149     }
150 
151     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
152         return -1;
153     }
154 
155     fsle = g_malloc0(sizeof(*fsle));
156     fsle->fse.fsdev_id = g_strdup(fsdev_id);
157     fsle->fse.ops = FsDrivers[i].ops;
158     if (writeout) {
159         if (!strcmp(writeout, "immediate")) {
160             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
161         }
162     }
163     if (ro) {
164         fsle->fse.export_flags |= V9FS_RDONLY;
165     } else {
166         fsle->fse.export_flags &= ~V9FS_RDONLY;
167     }
168 
169     if (fsle->fse.ops->parse_opts) {
170         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
171             g_free(fsle->fse.fsdev_id);
172             g_free(fsle);
173             return -1;
174         }
175     }
176 
177     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
178     return 0;
179 }
180 
181 FsDriverEntry *get_fsdev_fsentry(char *id)
182 {
183     if (id) {
184         struct FsDriverListEntry *fsle;
185 
186         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
187             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
188                 return &fsle->fse;
189             }
190         }
191     }
192     return NULL;
193 }
194