Annotation of qemu/block/qed-table.c, revision 1.1.1.3

1.1       root        1: /*
                      2:  * QEMU Enhanced Disk Format Table I/O
                      3:  *
                      4:  * Copyright IBM, Corp. 2010
                      5:  *
                      6:  * Authors:
                      7:  *  Stefan Hajnoczi   <[email protected]>
                      8:  *  Anthony Liguori   <[email protected]>
                      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 "trace.h"
                     16: #include "qemu_socket.h" /* for EINPROGRESS on Windows */
                     17: #include "qed.h"
                     18: 
                     19: typedef struct {
                     20:     GenericCB gencb;
                     21:     BDRVQEDState *s;
                     22:     QEDTable *table;
                     23: 
                     24:     struct iovec iov;
                     25:     QEMUIOVector qiov;
                     26: } QEDReadTableCB;
                     27: 
                     28: static void qed_read_table_cb(void *opaque, int ret)
                     29: {
                     30:     QEDReadTableCB *read_table_cb = opaque;
                     31:     QEDTable *table = read_table_cb->table;
                     32:     int noffsets = read_table_cb->iov.iov_len / sizeof(uint64_t);
                     33:     int i;
                     34: 
                     35:     /* Handle I/O error */
                     36:     if (ret) {
                     37:         goto out;
                     38:     }
                     39: 
                     40:     /* Byteswap offsets */
                     41:     for (i = 0; i < noffsets; i++) {
                     42:         table->offsets[i] = le64_to_cpu(table->offsets[i]);
                     43:     }
                     44: 
                     45: out:
                     46:     /* Completion */
                     47:     trace_qed_read_table_cb(read_table_cb->s, read_table_cb->table, ret);
                     48:     gencb_complete(&read_table_cb->gencb, ret);
                     49: }
                     50: 
                     51: static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
                     52:                            BlockDriverCompletionFunc *cb, void *opaque)
                     53: {
                     54:     QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb),
                     55:                                                 cb, opaque);
                     56:     QEMUIOVector *qiov = &read_table_cb->qiov;
                     57:     BlockDriverAIOCB *aiocb;
                     58: 
                     59:     trace_qed_read_table(s, offset, table);
                     60: 
                     61:     read_table_cb->s = s;
                     62:     read_table_cb->table = table;
                     63:     read_table_cb->iov.iov_base = table->offsets,
                     64:     read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size,
                     65: 
                     66:     qemu_iovec_init_external(qiov, &read_table_cb->iov, 1);
                     67:     aiocb = bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
                     68:                            read_table_cb->iov.iov_len / BDRV_SECTOR_SIZE,
                     69:                            qed_read_table_cb, read_table_cb);
                     70:     if (!aiocb) {
                     71:         qed_read_table_cb(read_table_cb, -EIO);
                     72:     }
                     73: }
                     74: 
                     75: typedef struct {
                     76:     GenericCB gencb;
                     77:     BDRVQEDState *s;
                     78:     QEDTable *orig_table;
                     79:     QEDTable *table;
                     80:     bool flush;             /* flush after write? */
                     81: 
                     82:     struct iovec iov;
                     83:     QEMUIOVector qiov;
                     84: } QEDWriteTableCB;
                     85: 
                     86: static void qed_write_table_cb(void *opaque, int ret)
                     87: {
                     88:     QEDWriteTableCB *write_table_cb = opaque;
                     89: 
                     90:     trace_qed_write_table_cb(write_table_cb->s,
                     91:                              write_table_cb->orig_table,
                     92:                              write_table_cb->flush,
                     93:                              ret);
                     94: 
                     95:     if (ret) {
                     96:         goto out;
                     97:     }
                     98: 
                     99:     if (write_table_cb->flush) {
                    100:         /* We still need to flush first */
                    101:         write_table_cb->flush = false;
                    102:         bdrv_aio_flush(write_table_cb->s->bs, qed_write_table_cb,
                    103:                        write_table_cb);
                    104:         return;
                    105:     }
                    106: 
                    107: out:
                    108:     qemu_vfree(write_table_cb->table);
                    109:     gencb_complete(&write_table_cb->gencb, ret);
                    110:     return;
                    111: }
                    112: 
                    113: /**
                    114:  * Write out an updated part or all of a table
                    115:  *
                    116:  * @s:          QED state
                    117:  * @offset:     Offset of table in image file, in bytes
                    118:  * @table:      Table
                    119:  * @index:      Index of first element
                    120:  * @n:          Number of elements
                    121:  * @flush:      Whether or not to sync to disk
                    122:  * @cb:         Completion function
                    123:  * @opaque:     Argument for completion function
                    124:  */
                    125: static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
                    126:                             unsigned int index, unsigned int n, bool flush,
                    127:                             BlockDriverCompletionFunc *cb, void *opaque)
                    128: {
                    129:     QEDWriteTableCB *write_table_cb;
                    130:     BlockDriverAIOCB *aiocb;
                    131:     unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
                    132:     unsigned int start, end, i;
                    133:     size_t len_bytes;
                    134: 
                    135:     trace_qed_write_table(s, offset, table, index, n);
                    136: 
                    137:     /* Calculate indices of the first and one after last elements */
                    138:     start = index & ~sector_mask;
                    139:     end = (index + n + sector_mask) & ~sector_mask;
                    140: 
                    141:     len_bytes = (end - start) * sizeof(uint64_t);
                    142: 
                    143:     write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque);
                    144:     write_table_cb->s = s;
                    145:     write_table_cb->orig_table = table;
                    146:     write_table_cb->flush = flush;
                    147:     write_table_cb->table = qemu_blockalign(s->bs, len_bytes);
                    148:     write_table_cb->iov.iov_base = write_table_cb->table->offsets;
                    149:     write_table_cb->iov.iov_len = len_bytes;
                    150:     qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1);
                    151: 
                    152:     /* Byteswap table */
                    153:     for (i = start; i < end; i++) {
                    154:         uint64_t le_offset = cpu_to_le64(table->offsets[i]);
                    155:         write_table_cb->table->offsets[i - start] = le_offset;
                    156:     }
                    157: 
                    158:     /* Adjust for offset into table */
                    159:     offset += start * sizeof(uint64_t);
                    160: 
                    161:     aiocb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
                    162:                             &write_table_cb->qiov,
                    163:                             write_table_cb->iov.iov_len / BDRV_SECTOR_SIZE,
                    164:                             qed_write_table_cb, write_table_cb);
                    165:     if (!aiocb) {
                    166:         qed_write_table_cb(write_table_cb, -EIO);
                    167:     }
                    168: }
                    169: 
                    170: /**
                    171:  * Propagate return value from async callback
                    172:  */
                    173: static void qed_sync_cb(void *opaque, int ret)
                    174: {
                    175:     *(int *)opaque = ret;
                    176: }
                    177: 
                    178: int qed_read_l1_table_sync(BDRVQEDState *s)
                    179: {
                    180:     int ret = -EINPROGRESS;
                    181: 
                    182:     qed_read_table(s, s->header.l1_table_offset,
                    183:                    s->l1_table, qed_sync_cb, &ret);
                    184:     while (ret == -EINPROGRESS) {
                    185:         qemu_aio_wait();
                    186:     }
                    187: 
                    188:     return ret;
                    189: }
                    190: 
                    191: void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
                    192:                         BlockDriverCompletionFunc *cb, void *opaque)
                    193: {
                    194:     BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
                    195:     qed_write_table(s, s->header.l1_table_offset,
                    196:                     s->l1_table, index, n, false, cb, opaque);
                    197: }
                    198: 
                    199: int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
                    200:                             unsigned int n)
                    201: {
                    202:     int ret = -EINPROGRESS;
                    203: 
                    204:     qed_write_l1_table(s, index, n, qed_sync_cb, &ret);
                    205:     while (ret == -EINPROGRESS) {
                    206:         qemu_aio_wait();
                    207:     }
                    208: 
                    209:     return ret;
                    210: }
                    211: 
                    212: typedef struct {
                    213:     GenericCB gencb;
                    214:     BDRVQEDState *s;
                    215:     uint64_t l2_offset;
                    216:     QEDRequest *request;
                    217: } QEDReadL2TableCB;
                    218: 
                    219: static void qed_read_l2_table_cb(void *opaque, int ret)
                    220: {
                    221:     QEDReadL2TableCB *read_l2_table_cb = opaque;
                    222:     QEDRequest *request = read_l2_table_cb->request;
                    223:     BDRVQEDState *s = read_l2_table_cb->s;
                    224:     CachedL2Table *l2_table = request->l2_table;
1.1.1.2   root      225:     uint64_t l2_offset = read_l2_table_cb->l2_offset;
1.1       root      226: 
                    227:     if (ret) {
                    228:         /* can't trust loaded L2 table anymore */
                    229:         qed_unref_l2_cache_entry(l2_table);
                    230:         request->l2_table = NULL;
                    231:     } else {
1.1.1.2   root      232:         l2_table->offset = l2_offset;
1.1       root      233: 
                    234:         qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
                    235: 
                    236:         /* This is guaranteed to succeed because we just committed the entry
                    237:          * to the cache.
                    238:          */
1.1.1.2   root      239:         request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
1.1       root      240:         assert(request->l2_table != NULL);
                    241:     }
                    242: 
                    243:     gencb_complete(&read_l2_table_cb->gencb, ret);
                    244: }
                    245: 
                    246: void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
                    247:                        BlockDriverCompletionFunc *cb, void *opaque)
                    248: {
                    249:     QEDReadL2TableCB *read_l2_table_cb;
                    250: 
                    251:     qed_unref_l2_cache_entry(request->l2_table);
                    252: 
                    253:     /* Check for cached L2 entry */
                    254:     request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset);
                    255:     if (request->l2_table) {
                    256:         cb(opaque, 0);
                    257:         return;
                    258:     }
                    259: 
                    260:     request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
                    261:     request->l2_table->table = qed_alloc_table(s);
                    262: 
                    263:     read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque);
                    264:     read_l2_table_cb->s = s;
                    265:     read_l2_table_cb->l2_offset = offset;
                    266:     read_l2_table_cb->request = request;
                    267: 
                    268:     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD);
                    269:     qed_read_table(s, offset, request->l2_table->table,
                    270:                    qed_read_l2_table_cb, read_l2_table_cb);
                    271: }
                    272: 
                    273: int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
                    274: {
                    275:     int ret = -EINPROGRESS;
                    276: 
                    277:     qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
                    278:     while (ret == -EINPROGRESS) {
                    279:         qemu_aio_wait();
                    280:     }
                    281: 
                    282:     return ret;
                    283: }
                    284: 
                    285: void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
                    286:                         unsigned int index, unsigned int n, bool flush,
                    287:                         BlockDriverCompletionFunc *cb, void *opaque)
                    288: {
                    289:     BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE);
                    290:     qed_write_table(s, request->l2_table->offset,
                    291:                     request->l2_table->table, index, n, flush, cb, opaque);
                    292: }
                    293: 
                    294: int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
                    295:                             unsigned int index, unsigned int n, bool flush)
                    296: {
                    297:     int ret = -EINPROGRESS;
                    298: 
                    299:     qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret);
                    300:     while (ret == -EINPROGRESS) {
                    301:         qemu_aio_wait();
                    302:     }
                    303: 
                    304:     return ret;
                    305: }

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