diff options
Diffstat (limited to 'qemu/block/qed.c')
| -rw-r--r-- | qemu/block/qed.c | 1693 |
1 files changed, 1693 insertions, 0 deletions
diff --git a/qemu/block/qed.c b/qemu/block/qed.c new file mode 100644 index 000000000..954ed007c --- /dev/null +++ b/qemu/block/qed.c @@ -0,0 +1,1693 @@ +/* + * 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); |