xref: /openbmc/qemu/fsdev/qemu-fsdev.c (revision 2e1cacfb)
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 
94 static int validate_opt(void *opaque, const char *name, const char *value,
95                         Error **errp)
96 {
97     FsDriverTable *drv = opaque;
98     const char **opt;
99 
100     for (opt = drv->opts; *opt; opt++) {
101         if (!strcmp(*opt, name)) {
102             return 0;
103         }
104     }
105 
106     error_setg(errp, "'%s' is invalid for fsdriver '%s'", name, drv->name);
107     return -1;
108 }
109 
110 int qemu_fsdev_add(QemuOpts *opts, Error **errp)
111 {
112     int i;
113     struct FsDriverListEntry *fsle;
114     const char *fsdev_id = qemu_opts_id(opts);
115     const char *fsdriver = qemu_opt_get(opts, "fsdriver");
116     const char *writeout = qemu_opt_get(opts, "writeout");
117     bool ro = qemu_opt_get_bool(opts, "readonly", 0);
118 
119     if (!fsdev_id) {
120         error_setg(errp, "fsdev: No id specified");
121         return -1;
122     }
123 
124     if (fsdriver) {
125         for (i = 0; i < ARRAY_SIZE(FsDrivers); i++) {
126             if (strcmp(FsDrivers[i].name, fsdriver) == 0) {
127                 break;
128             }
129         }
130 
131         if (i == ARRAY_SIZE(FsDrivers)) {
132             error_setg(errp, "fsdev: fsdriver %s not found", fsdriver);
133             return -1;
134         }
135     } else {
136         error_setg(errp, "fsdev: No fsdriver specified");
137         return -1;
138     }
139 
140     if (qemu_opt_foreach(opts, validate_opt, &FsDrivers[i], errp)) {
141         return -1;
142     }
143 
144     fsle = g_malloc0(sizeof(*fsle));
145     fsle->fse.fsdev_id = g_strdup(fsdev_id);
146     fsle->fse.ops = FsDrivers[i].ops;
147     if (writeout) {
148         if (!strcmp(writeout, "immediate")) {
149             fsle->fse.export_flags |= V9FS_IMMEDIATE_WRITEOUT;
150         }
151     }
152     if (ro) {
153         fsle->fse.export_flags |= V9FS_RDONLY;
154     } else {
155         fsle->fse.export_flags &= ~V9FS_RDONLY;
156     }
157 
158     if (fsle->fse.ops->parse_opts) {
159         if (fsle->fse.ops->parse_opts(opts, &fsle->fse, errp)) {
160             g_free(fsle->fse.fsdev_id);
161             g_free(fsle);
162             return -1;
163         }
164     }
165 
166     QTAILQ_INSERT_TAIL(&fsdriver_entries, fsle, next);
167     return 0;
168 }
169 
170 FsDriverEntry *get_fsdev_fsentry(char *id)
171 {
172     if (id) {
173         struct FsDriverListEntry *fsle;
174 
175         QTAILQ_FOREACH(fsle, &fsdriver_entries, next) {
176             if (strcmp(fsle->fse.fsdev_id, id) == 0) {
177                 return &fsle->fse;
178             }
179         }
180     }
181     return NULL;
182 }
183