--- /dev/null
+/*
+ * QEMU Enhanced Disk Format
+ *
+ * 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 "qemu/timer.h"
+#include "trace.h"
+#include "qed.h"
+#include "qapi/qmp/qerror.h"
+#include "migration/migration.h"
+
+static const AIOCBInfo qed_aiocb_info = {
+ .aiocb_size = sizeof(QEDAIOCB),
+};
+
+static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
+ const char *filename)
+{
+ const QEDHeader *header = (const QEDHeader *)buf;
+
+ if (buf_size < sizeof(*header)) {
+ return 0;
+ }
+ if (le32_to_cpu(header->magic) != QED_MAGIC) {
+ return 0;
+ }
+ return 100;
+}
+
+/**
+ * Check whether an image format is raw
+ *
+ * @fmt: Backing file format, may be NULL
+ */
+static bool qed_fmt_is_raw(const char *fmt)
+{
+ return fmt && strcmp(fmt, "raw") == 0;
+}
+
+static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu)
+{
+ cpu->magic = le32_to_cpu(le->magic);
+ cpu->cluster_size = le32_to_cpu(le->cluster_size);
+ cpu->table_size = le32_to_cpu(le->table_size);
+ cpu->header_size = le32_to_cpu(le->header_size);
+ cpu->features = le64_to_cpu(le->features);
+ cpu->compat_features = le64_to_cpu(le->compat_features);
+ cpu->autoclear_features = le64_to_cpu(le->autoclear_features);
+ cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset);
+ cpu->image_size = le64_to_cpu(le->image_size);
+ cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset);
+ cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size);
+}
+
+static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
+{
+ le->magic = cpu_to_le32(cpu->magic);
+ le->cluster_size = cpu_to_le32(cpu->cluster_size);
+ le->table_size = cpu_to_le32(cpu->table_size);
+ le->header_size = cpu_to_le32(cpu->header_size);
+ le->features = cpu_to_le64(cpu->features);
+ le->compat_features = cpu_to_le64(cpu->compat_features);
+ le->autoclear_features = cpu_to_le64(cpu->autoclear_features);
+ le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset);
+ le->image_size = cpu_to_le64(cpu->image_size);
+ le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset);
+ le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size);
+}
+
+int qed_write_header_sync(BDRVQEDState *s)
+{
+ QEDHeader le;
+ int ret;
+
+ qed_header_cpu_to_le(&s->header, &le);
+ ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le));
+ if (ret != sizeof(le)) {
+ return ret;
+ }
+ return 0;
+}
+
+typedef struct {
+ GenericCB gencb;
+ BDRVQEDState *s;
+ struct iovec iov;
+ QEMUIOVector qiov;
+ int nsectors;
+ uint8_t *buf;
+} QEDWriteHeaderCB;
+
+static void qed_write_header_cb(void *opaque, int ret)
+{
+ QEDWriteHeaderCB *write_header_cb = opaque;
+
+ qemu_vfree(write_header_cb->buf);
+ gencb_complete(write_header_cb, ret);
+}
+
+static void qed_write_header_read_cb(void *opaque, int ret)
+{
+ QEDWriteHeaderCB *write_header_cb = opaque;
+ BDRVQEDState *s = write_header_cb->s;
+
+ if (ret) {
+ qed_write_header_cb(write_header_cb, ret);
+ return;
+ }
+
+ /* Update header */
+ qed_header_cpu_to_le(&s->header, (QEDHeader *)write_header_cb->buf);
+
+ bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov,
+ write_header_cb->nsectors, qed_write_header_cb,
+ write_header_cb);
+}
+
+/**
+ * Update header in-place (does not rewrite backing filename or other strings)
+ *
+ * This function only updates known header fields in-place and does not affect
+ * extra data after the QED header.
+ */
+static void qed_write_header(BDRVQEDState *s, BlockCompletionFunc cb,
+ void *opaque)
+{
+ /* We must write full sectors for O_DIRECT but cannot necessarily generate
+ * the data following the header if an unrecognized compat feature is
+ * active. Therefore, first read the sectors containing the header, update
+ * them, and write back.
+ */
+
+ int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) /
+ BDRV_SECTOR_SIZE;
+ size_t len = nsectors * BDRV_SECTOR_SIZE;
+ QEDWriteHeaderCB *write_header_cb = gencb_alloc(sizeof(*write_header_cb),
+ cb, opaque);
+
+ write_header_cb->s = s;
+ write_header_cb->nsectors = nsectors;
+ write_header_cb->buf = qemu_blockalign(s->bs, len);
+ write_header_cb->iov.iov_base = write_header_cb->buf;
+ write_header_cb->iov.iov_len = len;
+ qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1);
+
+ bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors,
+ qed_write_header_read_cb, write_header_cb);
+}
+
+static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
+{
+ uint64_t table_entries;
+ uint64_t l2_size;
+
+ table_entries = (table_size * cluster_size) / sizeof(uint64_t);
+ l2_size = table_entries * cluster_size;
+
+ return l2_size * table_entries;
+}
+
+static bool qed_is_cluster_size_valid(uint32_t cluster_size)
+{
+ if (cluster_size < QED_MIN_CLUSTER_SIZE ||
+ cluster_size > QED_MAX_CLUSTER_SIZE) {
+ return false;
+ }
+ if (cluster_size & (cluster_size - 1)) {
+ return false; /* not power of 2 */
+ }
+ return true;
+}
+
+static bool qed_is_table_size_valid(uint32_t table_size)
+{
+ if (table_size < QED_MIN_TABLE_SIZE ||
+ table_size > QED_MAX_TABLE_SIZE) {
+ return false;
+ }
+ if (table_size & (table_size - 1)) {
+ return false; /* not power of 2 */
+ }
+ return true;
+}
+
+static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size,
+ uint32_t table_size)
+{
+ if (image_size % BDRV_SECTOR_SIZE != 0) {
+ return false; /* not multiple of sector size */
+ }
+ if (image_size > qed_max_image_size(cluster_size, table_size)) {
+ return false; /* image is too large */
+ }
+ return true;
+}
+
+/**
+ * Read a string of known length from the image file
+ *
+ * @file: Image file
+ * @offset: File offset to start of string, in bytes
+ * @n: String length in bytes
+ * @buf: Destination buffer
+ * @buflen: Destination buffer length in bytes
+ * @ret: 0 on success, -errno on failure
+ *
+ * The string is NUL-terminated.
+ */
+static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n,
+ char *buf, size_t buflen)
+{
+ int ret;
+ if (n >= buflen) {
+ return -EINVAL;
+ }
+ ret = bdrv_pread(file, offset, buf, n);
+ if (ret < 0) {
+ return ret;
+ }
+ buf[n] = '\0';
+ return 0;
+}
+
+/**
+ * Allocate new clusters
+ *
+ * @s: QED state
+ * @n: Number of contiguous clusters to allocate
+ * @ret: Offset of first allocated cluster
+ *
+ * This function only produces the offset where the new clusters should be
+ * written. It updates BDRVQEDState but does not make any changes to the image
+ * file.
+ */
+static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n)
+{
+ uint64_t offset = s->file_size;
+ s->file_size += n * s->header.cluster_size;
+ return offset;
+}
+
+QEDTable *qed_alloc_table(BDRVQEDState *s)
+{
+ /* Honor O_DIRECT memory alignment requirements */
+ return qemu_blockalign(s->bs,
+ s->header.cluster_size * s->header.table_size);
+}
+
+/**
+ * Allocate a new zeroed L2 table
+ */
+static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
+{
+ CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
+
+ l2_table->table = qed_alloc_table(s);
+ l2_table->offset = qed_alloc_clusters(s, s->header.table_size);
+
+ memset(l2_table->table->offsets, 0,
+ s->header.cluster_size * s->header.table_size);
+ return l2_table;
+}
+
+static void qed_aio_next_io(void *opaque, int ret);
+
+static void qed_plug_allocating_write_reqs(BDRVQEDState *s)
+{
+ assert(!s->allocating_write_reqs_plugged);
+
+ s->allocating_write_reqs_plugged = true;
+}
+
+static void qed_unplug_allocating_write_reqs(BDRVQEDState *s)
+{
+ QEDAIOCB *acb;
+
+ assert(s->allocating_write_reqs_plugged);
+
+ s->allocating_write_reqs_plugged = false;
+
+ acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs);
+ if (acb) {
+ qed_aio_next_io(acb, 0);
+ }
+}
+
+static void qed_finish_clear_need_check(void *opaque, int ret)
+{
+ /* Do nothing */
+}
+
+static void qed_flush_after_clear_need_check(void *opaque, int ret)
+{
+ BDRVQEDState *s = opaque;
+
+ bdrv_aio_flush(s->bs, qed_finish_clear_need_check, s);
+
+ /* No need to wait until flush completes */
+ qed_unplug_allocating_write_reqs(s);
+}
+
+static void qed_clear_need_check(void *opaque, int ret)
+{
+ BDRVQEDState *s = opaque;
+
+ if (ret) {
+ qed_unplug_allocating_write_reqs(s);
+ return;
+ }
+
+ s->header.features &= ~QED_F_NEED_CHECK;
+ qed_write_header(s, qed_flush_after_clear_need_check, s);
+}
+
+static void qed_need_check_timer_cb(void *opaque)
+{
+ BDRVQEDState *s = opaque;
+
+ /* The timer should only fire when allocating writes have drained */
+ assert(!QSIMPLEQ_FIRST(&s->allocating_write_reqs));
+
+ trace_qed_need_check_timer_cb(s);
+
+ qed_plug_allocating_write_reqs(s);
+
+ /* Ensure writes are on disk before clearing flag */
+ bdrv_aio_flush(s->bs, qed_clear_need_check, s);
+}
+
+static void qed_start_need_check_timer(BDRVQEDState *s)
+{
+ trace_qed_start_need_check_timer(s);
+
+ /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
+ * migration.
+ */
+ timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
+ get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT);
+}
+
+/* It's okay to call this multiple times or when no timer is started */
+static void qed_cancel_need_check_timer(BDRVQEDState *s)
+{
+ trace_qed_cancel_need_check_timer(s);
+ timer_del(s->need_check_timer);
+}
+
+static void bdrv_qed_rebind(BlockDriverState *bs)
+{
+ BDRVQEDState *s = bs->opaque;
+ s->bs = bs;
+}
+
+static void bdrv_qed_detach_aio_context(BlockDriverState *bs)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ qed_cancel_need_check_timer(s);
+ timer_free(s->need_check_timer);
+}
+
+static void bdrv_qed_attach_aio_context(BlockDriverState *bs,
+ AioContext *new_context)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ s->need_check_timer = aio_timer_new(new_context,
+ QEMU_CLOCK_VIRTUAL, SCALE_NS,
+ qed_need_check_timer_cb, s);
+ if (s->header.features & QED_F_NEED_CHECK) {
+ qed_start_need_check_timer(s);
+ }
+}
+
+static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ BDRVQEDState *s = bs->opaque;
+ QEDHeader le_header;
+ int64_t file_size;
+ int ret;
+
+ s->bs = bs;
+ QSIMPLEQ_INIT(&s->allocating_write_reqs);
+
+ ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header));
+ if (ret < 0) {
+ return ret;
+ }
+ qed_header_le_to_cpu(&le_header, &s->header);
+
+ if (s->header.magic != QED_MAGIC) {
+ error_setg(errp, "Image not in QED format");
+ return -EINVAL;
+ }
+ if (s->header.features & ~QED_FEATURE_MASK) {
+ /* image uses unsupported feature bits */
+ char buf[64];
+ snprintf(buf, sizeof(buf), "%" PRIx64,
+ s->header.features & ~QED_FEATURE_MASK);
+ error_setg(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+ bdrv_get_device_or_node_name(bs), "QED", buf);
+ return -ENOTSUP;
+ }
+ if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
+ return -EINVAL;
+ }
+
+ /* Round down file size to the last cluster */
+ file_size = bdrv_getlength(bs->file);
+ if (file_size < 0) {
+ return file_size;
+ }
+ s->file_size = qed_start_of_cluster(s, file_size);
+
+ if (!qed_is_table_size_valid(s->header.table_size)) {
+ return -EINVAL;
+ }
+ if (!qed_is_image_size_valid(s->header.image_size,
+ s->header.cluster_size,
+ s->header.table_size)) {
+ return -EINVAL;
+ }
+ if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
+ return -EINVAL;
+ }
+
+ s->table_nelems = (s->header.cluster_size * s->header.table_size) /
+ sizeof(uint64_t);
+ s->l2_shift = ctz32(s->header.cluster_size);
+ s->l2_mask = s->table_nelems - 1;
+ s->l1_shift = s->l2_shift + ctz32(s->table_nelems);
+
+ /* Header size calculation must not overflow uint32_t */
+ if (s->header.header_size > UINT32_MAX / s->header.cluster_size) {
+ return -EINVAL;
+ }
+
+ if ((s->header.features & QED_F_BACKING_FILE)) {
+ if ((uint64_t)s->header.backing_filename_offset +
+ s->header.backing_filename_size >
+ s->header.cluster_size * s->header.header_size) {
+ return -EINVAL;
+ }
+
+ ret = qed_read_string(bs->file, s->header.backing_filename_offset,
+ s->header.backing_filename_size, bs->backing_file,
+ sizeof(bs->backing_file));
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
+ pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
+ }
+ }
+
+ /* Reset unknown autoclear feature bits. This is a backwards
+ * compatibility mechanism that allows images to be opened by older
+ * programs, which "knock out" unknown feature bits. When an image is
+ * opened by a newer program again it can detect that the autoclear
+ * feature is no longer valid.
+ */
+ if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 &&
+ !bdrv_is_read_only(bs->file) && !(flags & BDRV_O_INCOMING)) {
+ s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK;
+
+ ret = qed_write_header_sync(s);
+ if (ret) {
+ return ret;
+ }
+
+ /* From here on only known autoclear feature bits are valid */
+ bdrv_flush(bs->file);
+ }
+
+ s->l1_table = qed_alloc_table(s);
+ qed_init_l2_cache(&s->l2_cache);
+
+ ret = qed_read_l1_table_sync(s);
+ if (ret) {
+ goto out;
+ }
+
+ /* If image was not closed cleanly, check consistency */
+ if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) {
+ /* Read-only images cannot be fixed. There is no risk of corruption
+ * since write operations are not possible. Therefore, allow
+ * potentially inconsistent images to be opened read-only. This can
+ * aid data recovery from an otherwise inconsistent image.
+ */
+ if (!bdrv_is_read_only(bs->file) &&
+ !(flags & BDRV_O_INCOMING)) {
+ BdrvCheckResult result = {0};
+
+ ret = qed_check(s, &result, true);
+ if (ret) {
+ goto out;
+ }
+ }
+ }
+
+ bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs));
+
+out:
+ if (ret) {
+ qed_free_l2_cache(&s->l2_cache);
+ qemu_vfree(s->l1_table);
+ }
+ return ret;
+}
+
+static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ bs->bl.write_zeroes_alignment = s->header.cluster_size >> BDRV_SECTOR_BITS;
+}
+
+/* We have nothing to do for QED reopen, stubs just return
+ * success */
+static int bdrv_qed_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ return 0;
+}
+
+static void bdrv_qed_close(BlockDriverState *bs)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ bdrv_qed_detach_aio_context(bs);
+
+ /* Ensure writes reach stable storage */
+ bdrv_flush(bs->file);
+
+ /* Clean shutdown, no check required on next open */
+ if (s->header.features & QED_F_NEED_CHECK) {
+ s->header.features &= ~QED_F_NEED_CHECK;
+ qed_write_header_sync(s);
+ }
+
+ qed_free_l2_cache(&s->l2_cache);
+ qemu_vfree(s->l1_table);
+}
+
+static int qed_create(const char *filename, uint32_t cluster_size,
+ uint64_t image_size, uint32_t table_size,
+ const char *backing_file, const char *backing_fmt,
+ QemuOpts *opts, Error **errp)
+{
+ QEDHeader header = {
+ .magic = QED_MAGIC,
+ .cluster_size = cluster_size,
+ .table_size = table_size,
+ .header_size = 1,
+ .features = 0,
+ .compat_features = 0,
+ .l1_table_offset = cluster_size,
+ .image_size = image_size,
+ };
+ QEDHeader le_header;
+ uint8_t *l1_table = NULL;
+ size_t l1_size = header.cluster_size * header.table_size;
+ Error *local_err = NULL;
+ int ret = 0;
+ BlockDriverState *bs;
+
+ ret = bdrv_create_file(filename, opts, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ return ret;
+ }
+
+ bs = NULL;
+ ret = bdrv_open(&bs, filename, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL, NULL,
+ &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ return ret;
+ }
+
+ /* File must start empty and grow, check truncate is supported */
+ ret = bdrv_truncate(bs, 0);
+ if (ret < 0) {
+ goto out;
+ }
+
+ if (backing_file) {
+ header.features |= QED_F_BACKING_FILE;
+ header.backing_filename_offset = sizeof(le_header);
+ header.backing_filename_size = strlen(backing_file);
+
+ if (qed_fmt_is_raw(backing_fmt)) {
+ header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
+ }
+ }
+
+ qed_header_cpu_to_le(&header, &le_header);
+ ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header));
+ if (ret < 0) {
+ goto out;
+ }
+ ret = bdrv_pwrite(bs, sizeof(le_header), backing_file,
+ header.backing_filename_size);
+ if (ret < 0) {
+ goto out;
+ }
+
+ l1_table = g_malloc0(l1_size);
+ ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size);
+ if (ret < 0) {
+ goto out;
+ }
+
+ ret = 0; /* success */
+out:
+ g_free(l1_table);
+ bdrv_unref(bs);
+ return ret;
+}
+
+static int bdrv_qed_create(const char *filename, QemuOpts *opts, Error **errp)
+{
+ uint64_t image_size = 0;
+ uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE;
+ uint32_t table_size = QED_DEFAULT_TABLE_SIZE;
+ char *backing_file = NULL;
+ char *backing_fmt = NULL;
+ int ret;
+
+ image_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+ BDRV_SECTOR_SIZE);
+ backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
+ backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
+ cluster_size = qemu_opt_get_size_del(opts,
+ BLOCK_OPT_CLUSTER_SIZE,
+ QED_DEFAULT_CLUSTER_SIZE);
+ table_size = qemu_opt_get_size_del(opts, BLOCK_OPT_TABLE_SIZE,
+ QED_DEFAULT_TABLE_SIZE);
+
+ if (!qed_is_cluster_size_valid(cluster_size)) {
+ error_setg(errp, "QED cluster size must be within range [%u, %u] "
+ "and power of 2",
+ QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE);
+ ret = -EINVAL;
+ goto finish;
+ }
+ if (!qed_is_table_size_valid(table_size)) {
+ error_setg(errp, "QED table size must be within range [%u, %u] "
+ "and power of 2",
+ QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE);
+ ret = -EINVAL;
+ goto finish;
+ }
+ if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) {
+ error_setg(errp, "QED image size must be a non-zero multiple of "
+ "cluster size and less than %" PRIu64 " bytes",
+ qed_max_image_size(cluster_size, table_size));
+ ret = -EINVAL;
+ goto finish;
+ }
+
+ ret = qed_create(filename, cluster_size, image_size, table_size,
+ backing_file, backing_fmt, opts, errp);
+
+finish:
+ g_free(backing_file);
+ g_free(backing_fmt);
+ return ret;
+}
+
+typedef struct {
+ BlockDriverState *bs;
+ Coroutine *co;
+ uint64_t pos;
+ int64_t status;
+ int *pnum;
+} QEDIsAllocatedCB;
+
+static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len)
+{
+ QEDIsAllocatedCB *cb = opaque;
+ BDRVQEDState *s = cb->bs->opaque;
+ *cb->pnum = len / BDRV_SECTOR_SIZE;
+ switch (ret) {
+ case QED_CLUSTER_FOUND:
+ offset |= qed_offset_into_cluster(s, cb->pos);
+ cb->status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset;
+ break;
+ case QED_CLUSTER_ZERO:
+ cb->status = BDRV_BLOCK_ZERO;
+ break;
+ case QED_CLUSTER_L2:
+ case QED_CLUSTER_L1:
+ cb->status = 0;
+ break;
+ default:
+ assert(ret < 0);
+ cb->status = ret;
+ break;
+ }
+
+ if (cb->co) {
+ qemu_coroutine_enter(cb->co, NULL);
+ }
+}
+
+static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ BDRVQEDState *s = bs->opaque;
+ size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE;
+ QEDIsAllocatedCB cb = {
+ .bs = bs,
+ .pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE,
+ .status = BDRV_BLOCK_OFFSET_MASK,
+ .pnum = pnum,
+ };
+ QEDRequest request = { .l2_table = NULL };
+
+ qed_find_cluster(s, &request, cb.pos, len, qed_is_allocated_cb, &cb);
+
+ /* Now sleep if the callback wasn't invoked immediately */
+ while (cb.status == BDRV_BLOCK_OFFSET_MASK) {
+ cb.co = qemu_coroutine_self();
+ qemu_coroutine_yield();
+ }
+
+ qed_unref_l2_cache_entry(request.l2_table);
+
+ return cb.status;
+}
+
+static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
+{
+ return acb->common.bs->opaque;
+}
+
+/**
+ * Read from the backing file or zero-fill if no backing file
+ *
+ * @s: QED state
+ * @pos: Byte position in device
+ * @qiov: Destination I/O vector
+ * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
+ * @cb: Completion function
+ * @opaque: User data for completion function
+ *
+ * This function reads qiov->size bytes starting at pos from the backing file.
+ * If there is no backing file then zeroes are read.
+ */
+static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
+ QEMUIOVector *qiov,
+ QEMUIOVector **backing_qiov,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ uint64_t backing_length = 0;
+ size_t size;
+
+ /* If there is a backing file, get its length. Treat the absence of a
+ * backing file like a zero length backing file.
+ */
+ if (s->bs->backing_hd) {
+ int64_t l = bdrv_getlength(s->bs->backing_hd);
+ if (l < 0) {
+ cb(opaque, l);
+ return;
+ }
+ backing_length = l;
+ }
+
+ /* Zero all sectors if reading beyond the end of the backing file */
+ if (pos >= backing_length ||
+ pos + qiov->size > backing_length) {
+ qemu_iovec_memset(qiov, 0, 0, qiov->size);
+ }
+
+ /* Complete now if there are no backing file sectors to read */
+ if (pos >= backing_length) {
+ cb(opaque, 0);
+ return;
+ }
+
+ /* If the read straddles the end of the backing file, shorten it */
+ size = MIN((uint64_t)backing_length - pos, qiov->size);
+
+ assert(*backing_qiov == NULL);
+ *backing_qiov = g_new(QEMUIOVector, 1);
+ qemu_iovec_init(*backing_qiov, qiov->niov);
+ qemu_iovec_concat(*backing_qiov, qiov, 0, size);
+
+ BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO);
+ bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE,
+ *backing_qiov, size / BDRV_SECTOR_SIZE, cb, opaque);
+}
+
+typedef struct {
+ GenericCB gencb;
+ BDRVQEDState *s;
+ QEMUIOVector qiov;
+ QEMUIOVector *backing_qiov;
+ struct iovec iov;
+ uint64_t offset;
+} CopyFromBackingFileCB;
+
+static void qed_copy_from_backing_file_cb(void *opaque, int ret)
+{
+ CopyFromBackingFileCB *copy_cb = opaque;
+ qemu_vfree(copy_cb->iov.iov_base);
+ gencb_complete(©_cb->gencb, ret);
+}
+
+static void qed_copy_from_backing_file_write(void *opaque, int ret)
+{
+ CopyFromBackingFileCB *copy_cb = opaque;
+ BDRVQEDState *s = copy_cb->s;
+
+ if (copy_cb->backing_qiov) {
+ qemu_iovec_destroy(copy_cb->backing_qiov);
+ g_free(copy_cb->backing_qiov);
+ copy_cb->backing_qiov = NULL;
+ }
+
+ if (ret) {
+ qed_copy_from_backing_file_cb(copy_cb, ret);
+ return;
+ }
+
+ BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
+ bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE,
+ ©_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE,
+ qed_copy_from_backing_file_cb, copy_cb);
+}
+
+/**
+ * Copy data from backing file into the image
+ *
+ * @s: QED state
+ * @pos: Byte position in device
+ * @len: Number of bytes
+ * @offset: Byte offset in image file
+ * @cb: Completion function
+ * @opaque: User data for completion function
+ */
+static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos,
+ uint64_t len, uint64_t offset,
+ BlockCompletionFunc *cb,
+ void *opaque)
+{
+ CopyFromBackingFileCB *copy_cb;
+
+ /* Skip copy entirely if there is no work to do */
+ if (len == 0) {
+ cb(opaque, 0);
+ return;
+ }
+
+ copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque);
+ copy_cb->s = s;
+ copy_cb->offset = offset;
+ copy_cb->backing_qiov = NULL;
+ copy_cb->iov.iov_base = qemu_blockalign(s->bs, len);
+ copy_cb->iov.iov_len = len;
+ qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1);
+
+ qed_read_backing_file(s, pos, ©_cb->qiov, ©_cb->backing_qiov,
+ qed_copy_from_backing_file_write, copy_cb);
+}
+
+/**
+ * Link one or more contiguous clusters into a table
+ *
+ * @s: QED state
+ * @table: L2 table
+ * @index: First cluster index
+ * @n: Number of contiguous clusters
+ * @cluster: First cluster offset
+ *
+ * The cluster offset may be an allocated byte offset in the image file, the
+ * zero cluster marker, or the unallocated cluster marker.
+ */
+static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index,
+ unsigned int n, uint64_t cluster)
+{
+ int i;
+ for (i = index; i < index + n; i++) {
+ table->offsets[i] = cluster;
+ if (!qed_offset_is_unalloc_cluster(cluster) &&
+ !qed_offset_is_zero_cluster(cluster)) {
+ cluster += s->header.cluster_size;
+ }
+ }
+}
+
+static void qed_aio_complete_bh(void *opaque)
+{
+ QEDAIOCB *acb = opaque;
+ BlockCompletionFunc *cb = acb->common.cb;
+ void *user_opaque = acb->common.opaque;
+ int ret = acb->bh_ret;
+
+ qemu_bh_delete(acb->bh);
+ qemu_aio_unref(acb);
+
+ /* Invoke callback */
+ cb(user_opaque, ret);
+}
+
+static void qed_aio_complete(QEDAIOCB *acb, int ret)
+{
+ BDRVQEDState *s = acb_to_s(acb);
+
+ trace_qed_aio_complete(s, acb, ret);
+
+ /* Free resources */
+ qemu_iovec_destroy(&acb->cur_qiov);
+ qed_unref_l2_cache_entry(acb->request.l2_table);
+
+ /* Free the buffer we may have allocated for zero writes */
+ if (acb->flags & QED_AIOCB_ZERO) {
+ qemu_vfree(acb->qiov->iov[0].iov_base);
+ acb->qiov->iov[0].iov_base = NULL;
+ }
+
+ /* Arrange for a bh to invoke the completion function */
+ acb->bh_ret = ret;
+ acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs),
+ qed_aio_complete_bh, acb);
+ qemu_bh_schedule(acb->bh);
+
+ /* Start next allocating write request waiting behind this one. Note that
+ * requests enqueue themselves when they first hit an unallocated cluster
+ * but they wait until the entire request is finished before waking up the
+ * next request in the queue. This ensures that we don't cycle through
+ * requests multiple times but rather finish one at a time completely.
+ */
+ if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
+ QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next);
+ acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs);
+ if (acb) {
+ qed_aio_next_io(acb, 0);
+ } else if (s->header.features & QED_F_NEED_CHECK) {
+ qed_start_need_check_timer(s);
+ }
+ }
+}
+
+/**
+ * Commit the current L2 table to the cache
+ */
+static void qed_commit_l2_update(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ CachedL2Table *l2_table = acb->request.l2_table;
+ uint64_t l2_offset = l2_table->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.
+ */
+ acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
+ assert(acb->request.l2_table != NULL);
+
+ qed_aio_next_io(opaque, ret);
+}
+
+/**
+ * Update L1 table with new L2 table offset and write it out
+ */
+static void qed_aio_write_l1_update(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ int index;
+
+ if (ret) {
+ qed_aio_complete(acb, ret);
+ return;
+ }
+
+ index = qed_l1_index(s, acb->cur_pos);
+ s->l1_table->offsets[index] = acb->request.l2_table->offset;
+
+ qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb);
+}
+
+/**
+ * Update L2 table with new cluster offsets and write them out
+ */
+static void qed_aio_write_l2_update(QEDAIOCB *acb, int ret, uint64_t offset)
+{
+ BDRVQEDState *s = acb_to_s(acb);
+ bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1;
+ int index;
+
+ if (ret) {
+ goto err;
+ }
+
+ if (need_alloc) {
+ qed_unref_l2_cache_entry(acb->request.l2_table);
+ acb->request.l2_table = qed_new_l2_table(s);
+ }
+
+ index = qed_l2_index(s, acb->cur_pos);
+ qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters,
+ offset);
+
+ if (need_alloc) {
+ /* Write out the whole new L2 table */
+ qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true,
+ qed_aio_write_l1_update, acb);
+ } else {
+ /* Write out only the updated part of the L2 table */
+ qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false,
+ qed_aio_next_io, acb);
+ }
+ return;
+
+err:
+ qed_aio_complete(acb, ret);
+}
+
+static void qed_aio_write_l2_update_cb(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ qed_aio_write_l2_update(acb, ret, acb->cur_cluster);
+}
+
+/**
+ * Flush new data clusters before updating the L2 table
+ *
+ * This flush is necessary when a backing file is in use. A crash during an
+ * allocating write could result in empty clusters in the image. If the write
+ * only touched a subregion of the cluster, then backing image sectors have
+ * been lost in the untouched region. The solution is to flush after writing a
+ * new data cluster and before updating the L2 table.
+ */
+static void qed_aio_write_flush_before_l2_update(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+
+ if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update_cb, opaque)) {
+ qed_aio_complete(acb, -EIO);
+ }
+}
+
+/**
+ * Write data to the image file
+ */
+static void qed_aio_write_main(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ uint64_t offset = acb->cur_cluster +
+ qed_offset_into_cluster(s, acb->cur_pos);
+ BlockCompletionFunc *next_fn;
+
+ trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size);
+
+ if (ret) {
+ qed_aio_complete(acb, ret);
+ return;
+ }
+
+ if (acb->find_cluster_ret == QED_CLUSTER_FOUND) {
+ next_fn = qed_aio_next_io;
+ } else {
+ if (s->bs->backing_hd) {
+ next_fn = qed_aio_write_flush_before_l2_update;
+ } else {
+ next_fn = qed_aio_write_l2_update_cb;
+ }
+ }
+
+ BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);
+ bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
+ &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE,
+ next_fn, acb);
+}
+
+/**
+ * Populate back untouched region of new data cluster
+ */
+static void qed_aio_write_postfill(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ uint64_t start = acb->cur_pos + acb->cur_qiov.size;
+ uint64_t len =
+ qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start;
+ uint64_t offset = acb->cur_cluster +
+ qed_offset_into_cluster(s, acb->cur_pos) +
+ acb->cur_qiov.size;
+
+ if (ret) {
+ qed_aio_complete(acb, ret);
+ return;
+ }
+
+ trace_qed_aio_write_postfill(s, acb, start, len, offset);
+ qed_copy_from_backing_file(s, start, len, offset,
+ qed_aio_write_main, acb);
+}
+
+/**
+ * Populate front untouched region of new data cluster
+ */
+static void qed_aio_write_prefill(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ uint64_t start = qed_start_of_cluster(s, acb->cur_pos);
+ uint64_t len = qed_offset_into_cluster(s, acb->cur_pos);
+
+ trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster);
+ qed_copy_from_backing_file(s, start, len, acb->cur_cluster,
+ qed_aio_write_postfill, acb);
+}
+
+/**
+ * Check if the QED_F_NEED_CHECK bit should be set during allocating write
+ */
+static bool qed_should_set_need_check(BDRVQEDState *s)
+{
+ /* The flush before L2 update path ensures consistency */
+ if (s->bs->backing_hd) {
+ return false;
+ }
+
+ return !(s->header.features & QED_F_NEED_CHECK);
+}
+
+static void qed_aio_write_zero_cluster(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+
+ if (ret) {
+ qed_aio_complete(acb, ret);
+ return;
+ }
+
+ qed_aio_write_l2_update(acb, 0, 1);
+}
+
+/**
+ * Write new data cluster
+ *
+ * @acb: Write request
+ * @len: Length in bytes
+ *
+ * This path is taken when writing to previously unallocated clusters.
+ */
+static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
+{
+ BDRVQEDState *s = acb_to_s(acb);
+ BlockCompletionFunc *cb;
+
+ /* Cancel timer when the first allocating request comes in */
+ if (QSIMPLEQ_EMPTY(&s->allocating_write_reqs)) {
+ qed_cancel_need_check_timer(s);
+ }
+
+ /* Freeze this request if another allocating write is in progress */
+ if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) {
+ QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next);
+ }
+ if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) ||
+ s->allocating_write_reqs_plugged) {
+ return; /* wait for existing request to finish */
+ }
+
+ acb->cur_nclusters = qed_bytes_to_clusters(s,
+ qed_offset_into_cluster(s, acb->cur_pos) + len);
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+
+ if (acb->flags & QED_AIOCB_ZERO) {
+ /* Skip ahead if the clusters are already zero */
+ if (acb->find_cluster_ret == QED_CLUSTER_ZERO) {
+ qed_aio_next_io(acb, 0);
+ return;
+ }
+
+ cb = qed_aio_write_zero_cluster;
+ } else {
+ cb = qed_aio_write_prefill;
+ acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);
+ }
+
+ if (qed_should_set_need_check(s)) {
+ s->header.features |= QED_F_NEED_CHECK;
+ qed_write_header(s, cb, acb);
+ } else {
+ cb(acb, 0);
+ }
+}
+
+/**
+ * Write data cluster in place
+ *
+ * @acb: Write request
+ * @offset: Cluster offset in bytes
+ * @len: Length in bytes
+ *
+ * This path is taken when writing to already allocated clusters.
+ */
+static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len)
+{
+ /* Allocate buffer for zero writes */
+ if (acb->flags & QED_AIOCB_ZERO) {
+ struct iovec *iov = acb->qiov->iov;
+
+ if (!iov->iov_base) {
+ iov->iov_base = qemu_try_blockalign(acb->common.bs, iov->iov_len);
+ if (iov->iov_base == NULL) {
+ qed_aio_complete(acb, -ENOMEM);
+ return;
+ }
+ memset(iov->iov_base, 0, iov->iov_len);
+ }
+ }
+
+ /* Calculate the I/O vector */
+ acb->cur_cluster = offset;
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+
+ /* Do the actual write */
+ qed_aio_write_main(acb, 0);
+}
+
+/**
+ * Write data cluster
+ *
+ * @opaque: Write request
+ * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
+ * or -errno
+ * @offset: Cluster offset in bytes
+ * @len: Length in bytes
+ *
+ * Callback from qed_find_cluster().
+ */
+static void qed_aio_write_data(void *opaque, int ret,
+ uint64_t offset, size_t len)
+{
+ QEDAIOCB *acb = opaque;
+
+ trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len);
+
+ acb->find_cluster_ret = ret;
+
+ switch (ret) {
+ case QED_CLUSTER_FOUND:
+ qed_aio_write_inplace(acb, offset, len);
+ break;
+
+ case QED_CLUSTER_L2:
+ case QED_CLUSTER_L1:
+ case QED_CLUSTER_ZERO:
+ qed_aio_write_alloc(acb, len);
+ break;
+
+ default:
+ qed_aio_complete(acb, ret);
+ break;
+ }
+}
+
+/**
+ * Read data cluster
+ *
+ * @opaque: Read request
+ * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1,
+ * or -errno
+ * @offset: Cluster offset in bytes
+ * @len: Length in bytes
+ *
+ * Callback from qed_find_cluster().
+ */
+static void qed_aio_read_data(void *opaque, int ret,
+ uint64_t offset, size_t len)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ BlockDriverState *bs = acb->common.bs;
+
+ /* Adjust offset into cluster */
+ offset += qed_offset_into_cluster(s, acb->cur_pos);
+
+ trace_qed_aio_read_data(s, acb, ret, offset, len);
+
+ if (ret < 0) {
+ goto err;
+ }
+
+ qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
+
+ /* Handle zero cluster and backing file reads */
+ if (ret == QED_CLUSTER_ZERO) {
+ qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size);
+ qed_aio_next_io(acb, 0);
+ return;
+ } else if (ret != QED_CLUSTER_FOUND) {
+ qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov,
+ &acb->backing_qiov, qed_aio_next_io, acb);
+ return;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE,
+ &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE,
+ qed_aio_next_io, acb);
+ return;
+
+err:
+ qed_aio_complete(acb, ret);
+}
+
+/**
+ * Begin next I/O or complete the request
+ */
+static void qed_aio_next_io(void *opaque, int ret)
+{
+ QEDAIOCB *acb = opaque;
+ BDRVQEDState *s = acb_to_s(acb);
+ QEDFindClusterFunc *io_fn = (acb->flags & QED_AIOCB_WRITE) ?
+ qed_aio_write_data : qed_aio_read_data;
+
+ trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size);
+
+ if (acb->backing_qiov) {
+ qemu_iovec_destroy(acb->backing_qiov);
+ g_free(acb->backing_qiov);
+ acb->backing_qiov = NULL;
+ }
+
+ /* Handle I/O error */
+ if (ret) {
+ qed_aio_complete(acb, ret);
+ return;
+ }
+
+ acb->qiov_offset += acb->cur_qiov.size;
+ acb->cur_pos += acb->cur_qiov.size;
+ qemu_iovec_reset(&acb->cur_qiov);
+
+ /* Complete request */
+ if (acb->cur_pos >= acb->end_pos) {
+ qed_aio_complete(acb, 0);
+ return;
+ }
+
+ /* Find next cluster and start I/O */
+ qed_find_cluster(s, &acb->request,
+ acb->cur_pos, acb->end_pos - acb->cur_pos,
+ io_fn, acb);
+}
+
+static BlockAIOCB *qed_aio_setup(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb,
+ void *opaque, int flags)
+{
+ QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque);
+
+ trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors,
+ opaque, flags);
+
+ acb->flags = flags;
+ acb->qiov = qiov;
+ acb->qiov_offset = 0;
+ acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE;
+ acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE;
+ acb->backing_qiov = NULL;
+ acb->request.l2_table = NULL;
+ qemu_iovec_init(&acb->cur_qiov, qiov->niov);
+
+ /* Start request */
+ qed_aio_next_io(acb, 0);
+ return &acb->common;
+}
+
+static BlockAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb,
+ void *opaque)
+{
+ return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+}
+
+static BlockAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors,
+ BlockCompletionFunc *cb,
+ void *opaque)
+{
+ return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb,
+ opaque, QED_AIOCB_WRITE);
+}
+
+typedef struct {
+ Coroutine *co;
+ int ret;
+ bool done;
+} QEDWriteZeroesCB;
+
+static void coroutine_fn qed_co_write_zeroes_cb(void *opaque, int ret)
+{
+ QEDWriteZeroesCB *cb = opaque;
+
+ cb->done = true;
+ cb->ret = ret;
+ if (cb->co) {
+ qemu_coroutine_enter(cb->co, NULL);
+ }
+}
+
+static int coroutine_fn bdrv_qed_co_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors,
+ BdrvRequestFlags flags)
+{
+ BlockAIOCB *blockacb;
+ BDRVQEDState *s = bs->opaque;
+ QEDWriteZeroesCB cb = { .done = false };
+ QEMUIOVector qiov;
+ struct iovec iov;
+
+ /* Refuse if there are untouched backing file sectors */
+ if (bs->backing_hd) {
+ if (qed_offset_into_cluster(s, sector_num * BDRV_SECTOR_SIZE) != 0) {
+ return -ENOTSUP;
+ }
+ if (qed_offset_into_cluster(s, nb_sectors * BDRV_SECTOR_SIZE) != 0) {
+ return -ENOTSUP;
+ }
+ }
+
+ /* Zero writes start without an I/O buffer. If a buffer becomes necessary
+ * then it will be allocated during request processing.
+ */
+ iov.iov_base = NULL,
+ iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE,
+
+ qemu_iovec_init_external(&qiov, &iov, 1);
+ blockacb = qed_aio_setup(bs, sector_num, &qiov, nb_sectors,
+ qed_co_write_zeroes_cb, &cb,
+ QED_AIOCB_WRITE | QED_AIOCB_ZERO);
+ if (!blockacb) {
+ return -EIO;
+ }
+ if (!cb.done) {
+ cb.co = qemu_coroutine_self();
+ qemu_coroutine_yield();
+ }
+ assert(cb.done);
+ return cb.ret;
+}
+
+static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset)
+{
+ BDRVQEDState *s = bs->opaque;
+ uint64_t old_image_size;
+ int ret;
+
+ if (!qed_is_image_size_valid(offset, s->header.cluster_size,
+ s->header.table_size)) {
+ return -EINVAL;
+ }
+
+ /* Shrinking is currently not supported */
+ if ((uint64_t)offset < s->header.image_size) {
+ return -ENOTSUP;
+ }
+
+ old_image_size = s->header.image_size;
+ s->header.image_size = offset;
+ ret = qed_write_header_sync(s);
+ if (ret < 0) {
+ s->header.image_size = old_image_size;
+ }
+ return ret;
+}
+
+static int64_t bdrv_qed_getlength(BlockDriverState *bs)
+{
+ BDRVQEDState *s = bs->opaque;
+ return s->header.image_size;
+}
+
+static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ memset(bdi, 0, sizeof(*bdi));
+ bdi->cluster_size = s->header.cluster_size;
+ bdi->is_dirty = s->header.features & QED_F_NEED_CHECK;
+ bdi->unallocated_blocks_are_zero = true;
+ bdi->can_write_zeroes_with_unmap = true;
+ return 0;
+}
+
+static int bdrv_qed_change_backing_file(BlockDriverState *bs,
+ const char *backing_file,
+ const char *backing_fmt)
+{
+ BDRVQEDState *s = bs->opaque;
+ QEDHeader new_header, le_header;
+ void *buffer;
+ size_t buffer_len, backing_file_len;
+ int ret;
+
+ /* Refuse to set backing filename if unknown compat feature bits are
+ * active. If the image uses an unknown compat feature then we may not
+ * know the layout of data following the header structure and cannot safely
+ * add a new string.
+ */
+ if (backing_file && (s->header.compat_features &
+ ~QED_COMPAT_FEATURE_MASK)) {
+ return -ENOTSUP;
+ }
+
+ memcpy(&new_header, &s->header, sizeof(new_header));
+
+ new_header.features &= ~(QED_F_BACKING_FILE |
+ QED_F_BACKING_FORMAT_NO_PROBE);
+
+ /* Adjust feature flags */
+ if (backing_file) {
+ new_header.features |= QED_F_BACKING_FILE;
+
+ if (qed_fmt_is_raw(backing_fmt)) {
+ new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
+ }
+ }
+
+ /* Calculate new header size */
+ backing_file_len = 0;
+
+ if (backing_file) {
+ backing_file_len = strlen(backing_file);
+ }
+
+ buffer_len = sizeof(new_header);
+ new_header.backing_filename_offset = buffer_len;
+ new_header.backing_filename_size = backing_file_len;
+ buffer_len += backing_file_len;
+
+ /* Make sure we can rewrite header without failing */
+ if (buffer_len > new_header.header_size * new_header.cluster_size) {
+ return -ENOSPC;
+ }
+
+ /* Prepare new header */
+ buffer = g_malloc(buffer_len);
+
+ qed_header_cpu_to_le(&new_header, &le_header);
+ memcpy(buffer, &le_header, sizeof(le_header));
+ buffer_len = sizeof(le_header);
+
+ if (backing_file) {
+ memcpy(buffer + buffer_len, backing_file, backing_file_len);
+ buffer_len += backing_file_len;
+ }
+
+ /* Write new header */
+ ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
+ g_free(buffer);
+ if (ret == 0) {
+ memcpy(&s->header, &new_header, sizeof(new_header));
+ }
+ return ret;
+}
+
+static void bdrv_qed_invalidate_cache(BlockDriverState *bs, Error **errp)
+{
+ BDRVQEDState *s = bs->opaque;
+ Error *local_err = NULL;
+ int ret;
+
+ bdrv_qed_close(bs);
+
+ bdrv_invalidate_cache(bs->file, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ memset(s, 0, sizeof(BDRVQEDState));
+ ret = bdrv_qed_open(bs, NULL, bs->open_flags, &local_err);
+ if (local_err) {
+ error_setg(errp, "Could not reopen qed layer: %s",
+ error_get_pretty(local_err));
+ error_free(local_err);
+ return;
+ } else if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not reopen qed layer");
+ return;
+ }
+}
+
+static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result,
+ BdrvCheckMode fix)
+{
+ BDRVQEDState *s = bs->opaque;
+
+ return qed_check(s, result, !!fix);
+}
+
+static QemuOptsList qed_create_opts = {
+ .name = "qed-create-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head),
+ .desc = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FILE,
+ .type = QEMU_OPT_STRING,
+ .help = "File name of a base image"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FMT,
+ .type = QEMU_OPT_STRING,
+ .help = "Image format of the base image"
+ },
+ {
+ .name = BLOCK_OPT_CLUSTER_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Cluster size (in bytes)",
+ .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE)
+ },
+ {
+ .name = BLOCK_OPT_TABLE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "L1/L2 table size (in clusters)"
+ },
+ { /* end of list */ }
+ }
+};
+
+static BlockDriver bdrv_qed = {
+ .format_name = "qed",
+ .instance_size = sizeof(BDRVQEDState),
+ .create_opts = &qed_create_opts,
+ .supports_backing = true,
+
+ .bdrv_probe = bdrv_qed_probe,
+ .bdrv_rebind = bdrv_qed_rebind,
+ .bdrv_open = bdrv_qed_open,
+ .bdrv_close = bdrv_qed_close,
+ .bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
+ .bdrv_create = bdrv_qed_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
+ .bdrv_co_get_block_status = bdrv_qed_co_get_block_status,
+ .bdrv_aio_readv = bdrv_qed_aio_readv,
+ .bdrv_aio_writev = bdrv_qed_aio_writev,
+ .bdrv_co_write_zeroes = bdrv_qed_co_write_zeroes,
+ .bdrv_truncate = bdrv_qed_truncate,
+ .bdrv_getlength = bdrv_qed_getlength,
+ .bdrv_get_info = bdrv_qed_get_info,
+ .bdrv_refresh_limits = bdrv_qed_refresh_limits,
+ .bdrv_change_backing_file = bdrv_qed_change_backing_file,
+ .bdrv_invalidate_cache = bdrv_qed_invalidate_cache,
+ .bdrv_check = bdrv_qed_check,
+ .bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
+ .bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
+};
+
+static void bdrv_qed_init(void)
+{
+ bdrv_register(&bdrv_qed);
+}
+
+block_init(bdrv_qed_init);
Code Review / kvmfornfv.git / blobdiff