1 /*
2  * QEMU System Emulator block driver
3  *
4  * Copyright (c) 2003 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #ifndef BLOCK_GLOBAL_STATE_H
25 #define BLOCK_GLOBAL_STATE_H
26 
27 #include "block-common.h"
28 
29 /*
30  * Global state (GS) API. These functions run under the BQL.
31  *
32  * If a function modifies the graph, it also uses drain and/or
33  * aio_context_acquire/release to be sure it has unique access.
34  * aio_context locking is needed together with BQL because of
35  * the thread-safe I/O API that concurrently runs and accesses
36  * the graph without the BQL.
37  *
38  * It is important to note that not all of these functions are
39  * necessarily limited to running under the BQL, but they would
40  * require additional auditing and many small thread-safety changes
41  * to move them into the I/O API. Often it's not worth doing that
42  * work since the APIs are only used with the BQL held at the
43  * moment, so they have been placed in the GS API (for now).
44  *
45  * These functions can call any function from this and other categories
46  * (I/O, "I/O or GS", Common), but must be invoked only by other GS APIs.
47  *
48  * All functions in this header must use the macro
49  * GLOBAL_STATE_CODE();
50  * to catch when they are accidentally called without the BQL.
51  */
52 
53 void bdrv_init(void);
54 BlockDriver *bdrv_find_protocol(const char *filename,
55                                 bool allow_protocol_prefix,
56                                 Error **errp);
57 BlockDriver *bdrv_find_format(const char *format_name);
58 
59 int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
60                                 QemuOpts *opts, Error **errp);
61 int co_wrapper bdrv_create(BlockDriver *drv, const char *filename,
62                            QemuOpts *opts, Error **errp);
63 
64 int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts,
65                                      Error **errp);
66 
67 BlockDriverState *bdrv_new(void);
68 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
69                 Error **errp);
70 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
71                       Error **errp);
72 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
73                           Error **errp);
74 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
75                                    int flags, Error **errp);
76 int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
77 
78 BdrvChild *bdrv_open_child(const char *filename,
79                            QDict *options, const char *bdref_key,
80                            BlockDriverState *parent,
81                            const BdrvChildClass *child_class,
82                            BdrvChildRole child_role,
83                            bool allow_none, Error **errp);
84 int bdrv_open_file_child(const char *filename,
85                          QDict *options, const char *bdref_key,
86                          BlockDriverState *parent, Error **errp);
87 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
88 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
89                         Error **errp);
90 int bdrv_set_backing_hd_drained(BlockDriverState *bs,
91                                 BlockDriverState *backing_hd,
92                                 Error **errp);
93 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
94                            const char *bdref_key, Error **errp);
95 BlockDriverState *bdrv_open(const char *filename, const char *reference,
96                             QDict *options, int flags, Error **errp);
97 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
98                                             const char *node_name,
99                                             QDict *options, int flags,
100                                             Error **errp);
101 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
102                                        int flags, Error **errp);
103 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
104                                     BlockDriverState *bs, QDict *options,
105                                     bool keep_old_opts);
106 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
107 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
108 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
109                 Error **errp);
110 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
111                               Error **errp);
112 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
113                                           const char *backing_file);
114 void bdrv_refresh_filename(BlockDriverState *bs);
115 void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
116 int bdrv_commit(BlockDriverState *bs);
117 int bdrv_make_empty(BdrvChild *c, Error **errp);
118 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
119                              const char *backing_fmt, bool warn);
120 void bdrv_register(BlockDriver *bdrv);
121 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
122                            const char *backing_file_str);
123 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
124                                     BlockDriverState *bs);
125 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
126 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
127                                   Error **errp);
128 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
129                               Error **errp);
130 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
131 
132 /*
133  * The units of offset and total_work_size may be chosen arbitrarily by the
134  * block driver; total_work_size may change during the course of the amendment
135  * operation
136  */
137 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
138                                       int64_t total_work_size, void *opaque);
139 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
140                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
141                        bool force,
142                        Error **errp);
143 
144 /* check if a named node can be replaced when doing drive-mirror */
145 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
146                                         const char *node_name, Error **errp);
147 
148 int bdrv_activate(BlockDriverState *bs, Error **errp);
149 void bdrv_activate_all(Error **errp);
150 int bdrv_inactivate_all(void);
151 
152 int bdrv_flush_all(void);
153 void bdrv_close_all(void);
154 void bdrv_drain_all_begin(void);
155 void bdrv_drain_all_begin_nopoll(void);
156 void bdrv_drain_all_end(void);
157 void bdrv_drain_all(void);
158 
159 int bdrv_has_zero_init_1(BlockDriverState *bs);
160 int bdrv_has_zero_init(BlockDriverState *bs);
161 BlockDriverState *bdrv_find_node(const char *node_name);
162 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
163 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
164 BlockDriverState *bdrv_lookup_bs(const char *device,
165                                  const char *node_name,
166                                  Error **errp);
167 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
168 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
169 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
170 
171 typedef struct BdrvNextIterator {
172     enum {
173         BDRV_NEXT_BACKEND_ROOTS,
174         BDRV_NEXT_MONITOR_OWNED,
175     } phase;
176     BlockBackend *blk;
177     BlockDriverState *bs;
178 } BdrvNextIterator;
179 
180 BlockDriverState *bdrv_first(BdrvNextIterator *it);
181 BlockDriverState *bdrv_next(BdrvNextIterator *it);
182 void bdrv_next_cleanup(BdrvNextIterator *it);
183 
184 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
185 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
186                          void *opaque, bool read_only);
187 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
188 char *bdrv_dirname(BlockDriverState *bs, Error **errp);
189 
190 void bdrv_img_create(const char *filename, const char *fmt,
191                      const char *base_filename, const char *base_fmt,
192                      char *options, uint64_t img_size, int flags,
193                      bool quiet, Error **errp);
194 
195 void bdrv_ref(BlockDriverState *bs);
196 void bdrv_unref(BlockDriverState *bs);
197 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
198 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
199                              BlockDriverState *child_bs,
200                              const char *child_name,
201                              const BdrvChildClass *child_class,
202                              BdrvChildRole child_role,
203                              Error **errp);
204 
205 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
206 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
207 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
208 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
209 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
210 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
211 
212 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
213                            const char *tag);
214 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
215 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
216 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
217 
218 /**
219  * Locks the AioContext of @bs if it's not the current AioContext. This avoids
220  * double locking which could lead to deadlocks: This is a coroutine_fn, so we
221  * know we already own the lock of the current AioContext.
222  *
223  * May only be called in the main thread.
224  */
225 void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
226 
227 /**
228  * Unlocks the AioContext of @bs if it's not the current AioContext.
229  */
230 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
231 
232 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
233                                    GHashTable *visited, Transaction *tran,
234                                    Error **errp);
235 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
236                                 BdrvChild *ignore_child, Error **errp);
237 
238 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
239 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
240 
241 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
242                     Error **errp);
243 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
244 
245 /**
246  *
247  * bdrv_register_buf/bdrv_unregister_buf:
248  *
249  * Register/unregister a buffer for I/O. For example, VFIO drivers are
250  * interested to know the memory areas that would later be used for I/O, so
251  * that they can prepare IOMMU mapping etc., to get better performance.
252  *
253  * Buffers must not overlap and they must be unregistered with the same <host,
254  * size> values that they were registered with.
255  *
256  * Returns: true on success, false on failure
257  */
258 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
259                        Error **errp);
260 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
261 
262 void bdrv_cancel_in_flight(BlockDriverState *bs);
263 
264 #endif /* BLOCK_GLOBAL_STATE_H */
265