/* * 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_socket.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); return; } /** * 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; }