diff options
Diffstat (limited to 'contrib/qemu/block/qed-table.c')
| -rw-r--r-- | contrib/qemu/block/qed-table.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/contrib/qemu/block/qed-table.c b/contrib/qemu/block/qed-table.c new file mode 100644 index 00000000000..76d2dcccf81 --- /dev/null +++ b/contrib/qemu/block/qed-table.c @@ -0,0 +1,296 @@ +/* + * QEMU Enhanced Disk Format Table I/O + * + * Copyright IBM, Corp. 2010 + * + * Authors: + * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> + * Anthony Liguori <aliguori@us.ibm.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "trace.h" +#include "qemu/sockets.h" /* for EINPROGRESS on Windows */ +#include "qed.h" + +typedef struct { + GenericCB gencb; + BDRVQEDState *s; + QEDTable *table; + + struct iovec iov; + QEMUIOVector qiov; +} QEDReadTableCB; + +static void qed_read_table_cb(void *opaque, int ret) +{ + QEDReadTableCB *read_table_cb = opaque; + QEDTable *table = read_table_cb->table; + int noffsets = read_table_cb->qiov.size / sizeof(uint64_t); + int i; + + /* Handle I/O error */ + if (ret) { + goto out; + } + + /* Byteswap offsets */ + for (i = 0; i < noffsets; i++) { + table->offsets[i] = le64_to_cpu(table->offsets[i]); + } + +out: + /* Completion */ + trace_qed_read_table_cb(read_table_cb->s, read_table_cb->table, ret); + gencb_complete(&read_table_cb->gencb, ret); +} + +static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, + BlockDriverCompletionFunc *cb, void *opaque) +{ + QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb), + cb, opaque); + QEMUIOVector *qiov = &read_table_cb->qiov; + + trace_qed_read_table(s, offset, table); + + read_table_cb->s = s; + read_table_cb->table = table; + read_table_cb->iov.iov_base = table->offsets, + read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size, + + qemu_iovec_init_external(qiov, &read_table_cb->iov, 1); + bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov, + qiov->size / BDRV_SECTOR_SIZE, + qed_read_table_cb, read_table_cb); +} + +typedef struct { + GenericCB gencb; + BDRVQEDState *s; + QEDTable *orig_table; + QEDTable *table; + bool flush; /* flush after write? */ + + struct iovec iov; + QEMUIOVector qiov; +} QEDWriteTableCB; + +static void qed_write_table_cb(void *opaque, int ret) +{ + QEDWriteTableCB *write_table_cb = opaque; + + trace_qed_write_table_cb(write_table_cb->s, + write_table_cb->orig_table, + write_table_cb->flush, + ret); + + if (ret) { + goto out; + } + + if (write_table_cb->flush) { + /* We still need to flush first */ + write_table_cb->flush = false; + bdrv_aio_flush(write_table_cb->s->bs, qed_write_table_cb, + write_table_cb); + return; + } + +out: + qemu_vfree(write_table_cb->table); + gencb_complete(&write_table_cb->gencb, ret); +} + +/** + * Write out an updated part or all of a table + * + * @s: QED state + * @offset: Offset of table in image file, in bytes + * @table: Table + * @index: Index of first element + * @n: Number of elements + * @flush: Whether or not to sync to disk + * @cb: Completion function + * @opaque: Argument for completion function + */ +static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table, + unsigned int index, unsigned int n, bool flush, + BlockDriverCompletionFunc *cb, void *opaque) +{ + QEDWriteTableCB *write_table_cb; + unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1; + unsigned int start, end, i; + size_t len_bytes; + + trace_qed_write_table(s, offset, table, index, n); + + /* Calculate indices of the first and one after last elements */ + start = index & ~sector_mask; + end = (index + n + sector_mask) & ~sector_mask; + + len_bytes = (end - start) * sizeof(uint64_t); + + write_table_cb = gencb_alloc(sizeof(*write_table_cb), cb, opaque); + write_table_cb->s = s; + write_table_cb->orig_table = table; + write_table_cb->flush = flush; + write_table_cb->table = qemu_blockalign(s->bs, len_bytes); + write_table_cb->iov.iov_base = write_table_cb->table->offsets; + write_table_cb->iov.iov_len = len_bytes; + qemu_iovec_init_external(&write_table_cb->qiov, &write_table_cb->iov, 1); + + /* Byteswap table */ + for (i = start; i < end; i++) { + uint64_t le_offset = cpu_to_le64(table->offsets[i]); + write_table_cb->table->offsets[i - start] = le_offset; + } + + /* Adjust for offset into table */ + offset += start * sizeof(uint64_t); + + bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, + &write_table_cb->qiov, + write_table_cb->qiov.size / BDRV_SECTOR_SIZE, + qed_write_table_cb, write_table_cb); +} + +/** + * Propagate return value from async callback + */ +static void qed_sync_cb(void *opaque, int ret) +{ + *(int *)opaque = ret; +} + +int qed_read_l1_table_sync(BDRVQEDState *s) +{ + int ret = -EINPROGRESS; + + qed_read_table(s, s->header.l1_table_offset, + s->l1_table, qed_sync_cb, &ret); + while (ret == -EINPROGRESS) { + qemu_aio_wait(); + } + + return ret; +} + +void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE); + qed_write_table(s, s->header.l1_table_offset, + s->l1_table, index, n, false, cb, opaque); +} + +int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index, + unsigned int n) +{ + int ret = -EINPROGRESS; + + qed_write_l1_table(s, index, n, qed_sync_cb, &ret); + while (ret == -EINPROGRESS) { + qemu_aio_wait(); + } + + return ret; +} + +typedef struct { + GenericCB gencb; + BDRVQEDState *s; + uint64_t l2_offset; + QEDRequest *request; +} QEDReadL2TableCB; + +static void qed_read_l2_table_cb(void *opaque, int ret) +{ + QEDReadL2TableCB *read_l2_table_cb = opaque; + QEDRequest *request = read_l2_table_cb->request; + BDRVQEDState *s = read_l2_table_cb->s; + CachedL2Table *l2_table = request->l2_table; + uint64_t l2_offset = read_l2_table_cb->l2_offset; + + if (ret) { + /* can't trust loaded L2 table anymore */ + qed_unref_l2_cache_entry(l2_table); + request->l2_table = NULL; + } else { + l2_table->offset = l2_offset; + + qed_commit_l2_cache_entry(&s->l2_cache, l2_table); + + /* This is guaranteed to succeed because we just committed the entry + * to the cache. + */ + request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); + assert(request->l2_table != NULL); + } + + gencb_complete(&read_l2_table_cb->gencb, ret); +} + +void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset, + BlockDriverCompletionFunc *cb, void *opaque) +{ + QEDReadL2TableCB *read_l2_table_cb; + + qed_unref_l2_cache_entry(request->l2_table); + + /* Check for cached L2 entry */ + request->l2_table = qed_find_l2_cache_entry(&s->l2_cache, offset); + if (request->l2_table) { + cb(opaque, 0); + return; + } + + request->l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); + request->l2_table->table = qed_alloc_table(s); + + read_l2_table_cb = gencb_alloc(sizeof(*read_l2_table_cb), cb, opaque); + read_l2_table_cb->s = s; + read_l2_table_cb->l2_offset = offset; + read_l2_table_cb->request = request; + + BLKDBG_EVENT(s->bs->file, BLKDBG_L2_LOAD); + qed_read_table(s, offset, request->l2_table->table, + qed_read_l2_table_cb, read_l2_table_cb); +} + +int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset) +{ + int ret = -EINPROGRESS; + + qed_read_l2_table(s, request, offset, qed_sync_cb, &ret); + while (ret == -EINPROGRESS) { + qemu_aio_wait(); + } + + return ret; +} + +void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request, + unsigned int index, unsigned int n, bool flush, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BLKDBG_EVENT(s->bs->file, BLKDBG_L2_UPDATE); + qed_write_table(s, request->l2_table->offset, + request->l2_table->table, index, n, flush, cb, opaque); +} + +int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request, + unsigned int index, unsigned int n, bool flush) +{ + int ret = -EINPROGRESS; + + qed_write_l2_table(s, request, index, n, flush, qed_sync_cb, &ret); + while (ret == -EINPROGRESS) { + qemu_aio_wait(); + } + + return ret; +} |