Revision 6583e3c7 block/qcow2-cluster.c
| b/block/qcow2-cluster.c | ||
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} |
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/* |
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* Writes one sector of the L1 table to the disk (can't update single entries |
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* and we really don't want bdrv_pread to perform a read-modify-write) |
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*/ |
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#define L1_ENTRIES_PER_SECTOR (512 / 8) |
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static int write_l1_entry(BDRVQcowState *s, int l1_index) |
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{
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uint64_t buf[L1_ENTRIES_PER_SECTOR]; |
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int l1_start_index; |
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int i; |
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l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); |
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for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) {
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buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); |
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} |
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if (bdrv_pwrite(s->hd, s->l1_table_offset + 8 * l1_start_index, |
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buf, sizeof(buf)) != sizeof(buf)) |
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{
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return -1; |
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} |
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return 0; |
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} |
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/* |
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* l2_allocate |
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* |
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* Allocate a new l2 entry in the file. If l1_index points to an already |
| ... | ... | |
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{
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BDRVQcowState *s = bs->opaque; |
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int min_index; |
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uint64_t old_l2_offset, tmp;
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uint64_t old_l2_offset; |
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uint64_t *l2_table, l2_offset; |
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old_l2_offset = s->l1_table[l1_index]; |
| ... | ... | |
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/* update the L1 entry */ |
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s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
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tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
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if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
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&tmp, sizeof(tmp)) != sizeof(tmp)) |
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if (write_l1_entry(s, l1_index) < 0) {
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return NULL; |
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} |
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/* allocate a new entry in the l2 cache */ |
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