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1 | /* | |
2 | * QEMU Enhanced Disk Format Table I/O | |
3 | * | |
4 | * Copyright IBM, Corp. 2010 | |
5 | * | |
6 | * Authors: | |
7 | * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | |
8 | * Anthony Liguori <aliguori@us.ibm.com> | |
9 | * | |
10 | * This work is licensed under the terms of the GNU LGPL, version 2 or later. | |
11 | * See the COPYING.LIB file in the top-level directory. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include "qemu/osdep.h" | |
16 | #include "block/block-io.h" | |
17 | #include "trace.h" | |
18 | #include "qemu/sockets.h" /* for EINPROGRESS on Windows */ | |
19 | #include "qed.h" | |
20 | #include "qemu/bswap.h" | |
21 | #include "qemu/memalign.h" | |
22 | ||
23 | /* Called with table_lock held. */ | |
24 | static int coroutine_fn GRAPH_RDLOCK | |
25 | qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table) | |
26 | { | |
27 | unsigned int bytes = s->header.cluster_size * s->header.table_size; | |
28 | ||
29 | int noffsets; | |
30 | int i, ret; | |
31 | ||
32 | trace_qed_read_table(s, offset, table); | |
33 | ||
34 | qemu_co_mutex_unlock(&s->table_lock); | |
35 | ret = bdrv_co_pread(s->bs->file, offset, bytes, table->offsets, 0); | |
36 | qemu_co_mutex_lock(&s->table_lock); | |
37 | if (ret < 0) { | |
38 | goto out; | |
39 | } | |
40 | ||
41 | /* Byteswap offsets */ | |
42 | noffsets = bytes / sizeof(uint64_t); | |
43 | for (i = 0; i < noffsets; i++) { | |
44 | table->offsets[i] = le64_to_cpu(table->offsets[i]); | |
45 | } | |
46 | ||
47 | ret = 0; | |
48 | out: | |
49 | /* Completion */ | |
50 | trace_qed_read_table_cb(s, table, ret); | |
51 | return ret; | |
52 | } | |
53 | ||
54 | /** | |
55 | * Write out an updated part or all of a table | |
56 | * | |
57 | * @s: QED state | |
58 | * @offset: Offset of table in image file, in bytes | |
59 | * @table: Table | |
60 | * @index: Index of first element | |
61 | * @n: Number of elements | |
62 | * @flush: Whether or not to sync to disk | |
63 | * | |
64 | * Called with table_lock held. | |
65 | */ | |
66 | static int coroutine_fn GRAPH_RDLOCK | |
67 | qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, | |
68 | unsigned int index, unsigned int n, bool flush) | |
69 | { | |
70 | unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1; | |
71 | unsigned int start, end, i; | |
72 | QEDTable *new_table; | |
73 | size_t len_bytes; | |
74 | int ret; | |
75 | ||
76 | trace_qed_write_table(s, offset, table, index, n); | |
77 | ||
78 | /* Calculate indices of the first and one after last elements */ | |
79 | start = index & ~sector_mask; | |
80 | end = (index + n + sector_mask) & ~sector_mask; | |
81 | ||
82 | len_bytes = (end - start) * sizeof(uint64_t); | |
83 | ||
84 | new_table = qemu_blockalign(s->bs, len_bytes); | |
85 | ||
86 | /* Byteswap table */ | |
87 | for (i = start; i < end; i++) { | |
88 | uint64_t le_offset = cpu_to_le64(table->offsets[i]); | |
89 | new_table->offsets[i - start] = le_offset; | |
90 | } | |
91 | ||
92 | /* Adjust for offset into table */ | |
93 | offset += start * sizeof(uint64_t); | |
94 | ||
95 | qemu_co_mutex_unlock(&s->table_lock); | |
96 | ret = bdrv_co_pwrite(s->bs->file, offset, len_bytes, new_table->offsets, 0); | |
97 | qemu_co_mutex_lock(&s->table_lock); | |
98 | trace_qed_write_table_cb(s, table, flush, ret); | |
99 | if (ret < 0) { | |
100 | goto out; | |
101 | } | |
102 | ||
103 | if (flush) { | |
104 | ret = bdrv_co_flush(s->bs); | |
105 | if (ret < 0) { | |
106 | goto out; | |
107 | } | |
108 | } | |
109 | ||
110 | ret = 0; | |
111 | out: | |
112 | qemu_vfree(new_table); | |
113 | return ret; | |
114 | } | |
115 | ||
116 | int coroutine_fn qed_read_l1_table_sync(BDRVQEDState *s) | |
117 | { | |
118 | return qed_read_table(s, s->header.l1_table_offset, s->l1_table); | |
119 | } | |
120 | ||
121 | /* Called with table_lock held. */ | |
122 | int coroutine_fn qed_write_l1_table(BDRVQEDState *s, unsigned int index, | |
123 | unsigned int n) | |
124 | { | |
125 | BLKDBG_CO_EVENT(s->bs->file, BLKDBG_L1_UPDATE); | |
126 | return qed_write_table(s, s->header.l1_table_offset, | |
127 | s->l1_table, index, n, false); | |
128 | } | |
129 | ||
130 | int coroutine_fn qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index, | |
131 | unsigned int n) | |
132 | { | |
133 | return qed_write_l1_table(s, index, n); | |
134 | } | |
135 | ||
136 | /* Called with table_lock held. */ | |
137 | int coroutine_fn qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, | |
138 | uint64_t offset) | |
139 | { | |
140 | int ret; | |
141 | ||
142 | qed_unref_l2_cache_entry(request->l2_table); | |
143 | ||
144 | /* Check for cached L2 entry */ | |
145 | request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset); | |
146 | if (request->l2_table) { | |
147 | return 0; | |
148 | } | |
149 | ||
150 | request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); | |
151 | request->l2_table->table = qed_alloc_table(s); | |
152 | ||
153 | BLKDBG_CO_EVENT(s->bs->file, BLKDBG_L2_LOAD); | |
154 | ret = qed_read_table(s, offset, request->l2_table->table); | |
155 | ||
156 | if (ret) { | |
157 | /* can't trust loaded L2 table anymore */ | |
158 | qed_unref_l2_cache_entry(request->l2_table); | |
159 | request->l2_table = NULL; | |
160 | } else { | |
161 | request->l2_table->offset = offset; | |
162 | ||
163 | qed_commit_l2_cache_entry(&s->l2_cache, request->l2_table); | |
164 | ||
165 | /* This is guaranteed to succeed because we just committed the entry | |
166 | * to the cache. | |
167 | */ | |
168 | request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset); | |
169 | assert(request->l2_table != NULL); | |
170 | } | |
171 | ||
172 | return ret; | |
173 | } | |
174 | ||
175 | int coroutine_fn qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, | |
176 | uint64_t offset) | |
177 | { | |
178 | return qed_read_l2_table(s, request, offset); | |
179 | } | |
180 | ||
181 | /* Called with table_lock held. */ | |
182 | int coroutine_fn qed_write_l2_table(BDRVQEDState *s, QEDRequest *request, | |
183 | unsigned int index, unsigned int n, | |
184 | bool flush) | |
185 | { | |
186 | BLKDBG_CO_EVENT(s->bs->file, BLKDBG_L2_UPDATE); | |
187 | return qed_write_table(s, request->l2_table->offset, | |
188 | request->l2_table->table, index, n, flush); | |
189 | } | |
190 | ||
191 | int coroutine_fn qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request, | |
192 | unsigned int index, unsigned int n, | |
193 | bool flush) | |
194 | { | |
195 | return qed_write_l2_table(s, request, index, n, flush); | |
196 | } |