xref: /openbmc/qemu/include/block/block_int-io.h (revision 87417811)
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_INT_IO_H
25 #define BLOCK_INT_IO_H
26 
27 #include "block/block_int-common.h"
28 #include "qemu/hbitmap.h"
29 #include "qemu/main-loop.h"
30 
31 /*
32  * I/O API functions. These functions are thread-safe.
33  *
34  * See include/block/block-io.h for more information about
35  * the I/O API.
36  */
37 
38 int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv_snapshot(BdrvChild *child,
39     int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset);
40 int coroutine_fn GRAPH_RDLOCK bdrv_co_snapshot_block_status(
41     BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes,
42     int64_t *pnum, int64_t *map, BlockDriverState **file);
43 int coroutine_fn GRAPH_RDLOCK bdrv_co_pdiscard_snapshot(BlockDriverState *bs,
44     int64_t offset, int64_t bytes);
45 
46 
47 int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv(BdrvChild *child,
48     int64_t offset, int64_t bytes, QEMUIOVector *qiov,
49     BdrvRequestFlags flags);
50 int coroutine_fn GRAPH_RDLOCK bdrv_co_preadv_part(BdrvChild *child,
51     int64_t offset, int64_t bytes,
52     QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
53 int coroutine_fn GRAPH_RDLOCK bdrv_co_pwritev(BdrvChild *child,
54     int64_t offset, int64_t bytes, QEMUIOVector *qiov,
55     BdrvRequestFlags flags);
56 int coroutine_fn GRAPH_RDLOCK bdrv_co_pwritev_part(BdrvChild *child,
57     int64_t offset, int64_t bytes,
58     QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
59 
60 static inline int coroutine_fn GRAPH_RDLOCK bdrv_co_pread(BdrvChild *child,
61     int64_t offset, int64_t bytes, void *buf, BdrvRequestFlags flags)
62 {
63     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
64     IO_CODE();
65     assert_bdrv_graph_readable();
66 
67     return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
68 }
69 
70 static inline int coroutine_fn GRAPH_RDLOCK bdrv_co_pwrite(BdrvChild *child,
71     int64_t offset, int64_t bytes, const void *buf, BdrvRequestFlags flags)
72 {
73     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
74     IO_CODE();
75     assert_bdrv_graph_readable();
76 
77     return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
78 }
79 
80 void coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
81                                                 uint64_t align);
82 BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
83 
84 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
85                             const char *filename);
86 
87 /**
88  * bdrv_wakeup:
89  * @bs: The BlockDriverState for which an I/O operation has been completed.
90  *
91  * Wake up the main thread if it is waiting on BDRV_POLL_WHILE.  During
92  * synchronous I/O on a BlockDriverState that is attached to another
93  * I/O thread, the main thread lets the I/O thread's event loop run,
94  * waiting for the I/O operation to complete.  A bdrv_wakeup will wake
95  * up the main thread if necessary.
96  *
97  * Manual calls to bdrv_wakeup are rarely necessary, because
98  * bdrv_dec_in_flight already calls it.
99  */
100 void bdrv_wakeup(BlockDriverState *bs);
101 
102 const char * GRAPH_RDLOCK bdrv_get_parent_name(const BlockDriverState *bs);
103 bool blk_dev_has_tray(BlockBackend *blk);
104 bool blk_dev_is_tray_open(BlockBackend *blk);
105 
106 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
107 
108 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
109 void bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
110                                       const BdrvDirtyBitmap *src,
111                                       HBitmap **backup, bool lock);
112 
113 void bdrv_inc_in_flight(BlockDriverState *bs);
114 void bdrv_dec_in_flight(BlockDriverState *bs);
115 
116 int coroutine_fn GRAPH_RDLOCK
117 bdrv_co_copy_range_from(BdrvChild *src, int64_t src_offset,
118                         BdrvChild *dst, int64_t dst_offset,
119                         int64_t bytes, BdrvRequestFlags read_flags,
120                         BdrvRequestFlags write_flags);
121 int coroutine_fn GRAPH_RDLOCK
122 bdrv_co_copy_range_to(BdrvChild *src, int64_t src_offset,
123                       BdrvChild *dst, int64_t dst_offset,
124                       int64_t bytes, BdrvRequestFlags read_flags,
125                       BdrvRequestFlags write_flags);
126 
127 int coroutine_fn GRAPH_RDLOCK
128 bdrv_co_refresh_total_sectors(BlockDriverState *bs, int64_t hint);
129 
130 int co_wrapper_mixed_bdrv_rdlock
131 bdrv_refresh_total_sectors(BlockDriverState *bs, int64_t hint);
132 
133 BdrvChild *bdrv_cow_child(BlockDriverState *bs);
134 BdrvChild *bdrv_filter_child(BlockDriverState *bs);
135 BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs);
136 BdrvChild * GRAPH_RDLOCK bdrv_primary_child(BlockDriverState *bs);
137 BlockDriverState *bdrv_skip_filters(BlockDriverState *bs);
138 BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs);
139 
140 static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs)
141 {
142     IO_CODE();
143     return child_bs(bdrv_cow_child(bs));
144 }
145 
146 static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs)
147 {
148     IO_CODE();
149     return child_bs(bdrv_filter_child(bs));
150 }
151 
152 static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs)
153 {
154     IO_CODE();
155     return child_bs(bdrv_filter_or_cow_child(bs));
156 }
157 
158 static inline BlockDriverState * GRAPH_RDLOCK
159 bdrv_primary_bs(BlockDriverState *bs)
160 {
161     IO_CODE();
162     return child_bs(bdrv_primary_child(bs));
163 }
164 
165 /**
166  * Check whether the given offset is in the cached block-status data
167  * region.
168  *
169  * If it is, and @pnum is not NULL, *pnum is set to
170  * `bsc.data_end - offset`, i.e. how many bytes, starting from
171  * @offset, are data (according to the cache).
172  * Otherwise, *pnum is not touched.
173  */
174 bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum);
175 
176 /**
177  * If [offset, offset + bytes) overlaps with the currently cached
178  * block-status region, invalidate the cache.
179  *
180  * (To be used by I/O paths that cause data regions to be zero or
181  * holes.)
182  */
183 void bdrv_bsc_invalidate_range(BlockDriverState *bs,
184                                int64_t offset, int64_t bytes);
185 
186 /**
187  * Mark the range [offset, offset + bytes) as a data region.
188  */
189 void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes);
190 
191 #endif /* BLOCK_INT_IO_H */
192