xref: /qemu/block/qed-table.c (revision b30d1886) 
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 "trace.h"
17 #include "qemu/sockets.h" /* for EINPROGRESS on Windows */
18 #include "qed.h"
19 #include "qemu/bswap.h"
20 
21 typedef struct {
22     GenericCB gencb;
23     BDRVQEDState *s;
24     QEDTable *table;
25 
26     struct iovec iov;
27     QEMUIOVector qiov;
28 } QEDReadTableCB;
29 
30 static void qed_read_table_cb(void *opaque, int ret)
31 {
32     QEDReadTableCB *read_table_cb = opaque;
33     QEDTable *table = read_table_cb->table;
34     BDRVQEDState *s = read_table_cb->s;
35     int noffsets = read_table_cb->qiov.size / sizeof(uint64_t);
36     int i;
37 
38     /* Handle I/O error */
39     if (ret) {
40         goto out;
41     }
42 
43     /* Byteswap offsets */
44     qed_acquire(s);
45     for (i = 0; i < noffsets; i++) {
46         table->offsets[i] = le64_to_cpu(table->offsets[i]);
47     }
48     qed_release(s);
49 
50 out:
51     /* Completion */
52     trace_qed_read_table_cb(s, read_table_cb->table, ret);
53     gencb_complete(&read_table_cb->gencb, ret);
54 }
55 
56 static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
57                            BlockCompletionFunc *cb, void *opaque)
58 {
59     QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb),
60                                                 cb, opaque);
61     QEMUIOVector *qiov = &read_table_cb->qiov;
62 
63     trace_qed_read_table(s, offset, table);
64 
65     read_table_cb->s = s;
66     read_table_cb->table = table;
67     read_table_cb->iov.iov_base = table->offsets,
68     read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size,
69 
70     qemu_iovec_init_external(qiov, &read_table_cb->iov, 1);
71     bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
72                    qiov->size / BDRV_SECTOR_SIZE,
73                    qed_read_table_cb, read_table_cb);
74 }
75 
76 typedef struct {
77     GenericCB gencb;
78     BDRVQEDState *s;
79     QEDTable *orig_table;
80     QEDTable *table;
81     bool flush;             /* flush after write? */
82 
83     struct iovec iov;
84     QEMUIOVector qiov;
85 } QEDWriteTableCB;
86 
87 static void qed_write_table_cb(void *opaque, int ret)
88 {
89     QEDWriteTableCB *write_table_cb = opaque;
90     BDRVQEDState *s = write_table_cb->s;
91 
92     trace_qed_write_table_cb(s,
93                              write_table_cb->orig_table,
94                              write_table_cb->flush,
95                              ret);
96 
97     if (ret) {
98         goto out;
99     }
100 
101     if (write_table_cb->flush) {
102         /* We still need to flush first */
103         write_table_cb->flush = false;
104         qed_acquire(s);
105         bdrv_aio_flush(write_table_cb->s->bs, qed_write_table_cb,
106                        write_table_cb);
107         qed_release(s);
108         return;
109     }
110 
111 out:
112     qemu_vfree(write_table_cb->table);
113     gencb_complete(&write_table_cb->gencb, ret);
114 }
115 
116 /**
117  * Write out an updated part or all of a table
118  *
119  * @s:          QED state
120  * @offset:     Offset of table in image file, in bytes
121  * @table:      Table
122  * @index:      Index of first element
123  * @n:          Number of elements
124  * @flush:      Whether or not to sync to disk
125  * @cb:         Completion function
126  * @opaque:     Argument for completion function
127  */
128 static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
129                             unsigned int index, unsigned int n, bool flush,
130                             BlockCompletionFunc *cb, void *opaque)
131 {
132     QEDWriteTableCB *write_table_cb;
133     unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
134     unsigned int start, end, i;
135     size_t len_bytes;
136 
137     trace_qed_write_table(s, offset, table, index, n);
138 
139     /* Calculate indices of the first and one after last elements */
140     start = index & ~sector_mask;
141     end = (index + n + sector_mask) & ~sector_mask;
142 
143     len_bytes = (end - start) * sizeof(uint64_t);
144 
145     write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque);
146     write_table_cb->s = s;
147     write_table_cb->orig_table = table;
148     write_table_cb->flush = flush;
149     write_table_cb->table = qemu_blockalign(s->bs, len_bytes);
150     write_table_cb->iov.iov_base = write_table_cb->table->offsets;
151     write_table_cb->iov.iov_len = len_bytes;
152     qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1);
153 
154     /* Byteswap table */
155     for (i = start; i < end; i++) {
156         uint64_t le_offset = cpu_to_le64(table->offsets[i]);
157         write_table_cb->table->offsets[i - start] = le_offset;
158     }
159 
160     /* Adjust for offset into table */
161     offset += start * sizeof(uint64_t);
162 
163     bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
164                     &write_table_cb->qiov,
165                     write_table_cb->qiov.size / BDRV_SECTOR_SIZE,
166                     qed_write_table_cb, write_table_cb);
167 }
168 
169 /**
170  * Propagate return value from async callback
171  */
172 static void qed_sync_cb(void *opaque, int ret)
173 {
174     *(int *)opaque = ret;
175 }
176 
177 int qed_read_l1_table_sync(BDRVQEDState *s)
178 {
179     int ret = -EINPROGRESS;
180 
181     qed_read_table(s, s->header.l1_table_offset,
182                    s->l1_table, qed_sync_cb, &ret);
183     BDRV_POLL_WHILE(s->bs, ret == -EINPROGRESS);
184 
185     return ret;
186 }
187 
188 void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
189                         BlockCompletionFunc *cb, void *opaque)
190 {
191     BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
192     qed_write_table(s, s->header.l1_table_offset,
193                     s->l1_table, index, n, false, cb, opaque);
194 }
195 
196 int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
197                             unsigned int n)
198 {
199     int ret = -EINPROGRESS;
200 
201     qed_write_l1_table(s, index, n, qed_sync_cb, &ret);
202     BDRV_POLL_WHILE(s->bs, ret == -EINPROGRESS);
203 
204     return ret;
205 }
206 
207 typedef struct {
208     GenericCB gencb;
209     BDRVQEDState *s;
210     uint64_t l2_offset;
211     QEDRequest *request;
212 } QEDReadL2TableCB;
213 
214 static void qed_read_l2_table_cb(void *opaque, int ret)
215 {
216     QEDReadL2TableCB *read_l2_table_cb = opaque;
217     QEDRequest *request = read_l2_table_cb->request;
218     BDRVQEDState *s = read_l2_table_cb->s;
219     CachedL2Table *l2_table = request->l2_table;
220     uint64_t l2_offset = read_l2_table_cb->l2_offset;
221 
222     qed_acquire(s);
223     if (ret) {
224         /* can't trust loaded L2 table anymore */
225         qed_unref_l2_cache_entry(l2_table);
226         request->l2_table = NULL;
227     } else {
228         l2_table->offset = l2_offset;
229 
230         qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
231 
232         /* This is guaranteed to succeed because we just committed the entry
233          * to the cache.
234          */
235         request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
236         assert(request->l2_table != NULL);
237     }
238     qed_release(s);
239 
240     gencb_complete(&read_l2_table_cb->gencb, ret);
241 }
242 
243 void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
244                        BlockCompletionFunc *cb, void *opaque)
245 {
246     QEDReadL2TableCB *read_l2_table_cb;
247 
248     qed_unref_l2_cache_entry(request->l2_table);
249 
250     /* Check for cached L2 entry */
251     request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
252     if (request->l2_table) {
253         cb(opaque, 0);
254         return;
255     }
256 
257     request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
258     request->l2_table->table = qed_alloc_table(s);
259 
260     read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque);
261     read_l2_table_cb->s = s;
262     read_l2_table_cb->l2_offset = offset;
263     read_l2_table_cb->request = request;
264 
265     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
266     qed_read_table(s, offset, request->l2_table->table,
267                    qed_read_l2_table_cb, read_l2_table_cb);
268 }
269 
270 int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
271 {
272     int ret = -EINPROGRESS;
273 
274     qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
275     BDRV_POLL_WHILE(s->bs, ret == -EINPROGRESS);
276 
277     return ret;
278 }
279 
280 void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
281                         unsigned int index, unsigned int n, bool flush,
282                         BlockCompletionFunc *cb, void *opaque)
283 {
284     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE);
285     qed_write_table(s, request->l2_table->offset,
286                     request->l2_table->table, index, n, flush, cb, opaque);
287 }
288 
289 int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
290                             unsigned int index, unsigned int n, bool flush)
291 {
292     int ret = -EINPROGRESS;
293 
294     qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret);
295     BDRV_POLL_WHILE(s->bs, ret == -EINPROGRESS);
296 
297     return ret;
298 }
299