Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qcow2: Use worker threads for compression to improve performance of
  'qemu-img convert -W' and compressed backup jobs
- blklogwrites: New filter driver to log write requests to an image in
  the dm-log-writes format
- file-posix: Fix image locking during image creation
- crypto: Fix memory leak in error path
- Error out instead of silently truncating node names

# gpg: Signature made Thu 05 Jul 2018 11:24:33 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  file-posix: Unlock FD after creation
  file-posix: Fix creation locking
  block/blklogwrites: Add an option for the update interval of the log superblock
  block/blklogwrites: Add an option for appending to an old log
  block/blklogwrites: Change log_sector_size from int64_t to uint64_t
  block/crypto: Fix memory leak in create error path
  block: Don't silently truncate node names
  block: Add blklogwrites
  block: Move two block permission constants to the relevant enum
  qcow2: add compress threads
  qcow2: refactor data compression
  qemu-img: allow compressed not-in-order writes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 679 insertions, 33 deletions

diff --git a/block/Makefile.objs b/block/Makefile.objs
index 899bfb5e2c..c8337bf186 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -5,6 +5,7 @@ block-obj-y += qed-check.o
 block-obj-y += vhdx.o vhdx-endian.o vhdx-log.o
 block-obj-y += quorum.o
 block-obj-y += parallels.o blkdebug.o blkverify.o blkreplay.o
+block-obj-y += blklogwrites.o
 block-obj-y += block-backend.o snapshot.o qapi.o
 block-obj-$(CONFIG_WIN32) += file-win32.o win32-aio.o
 block-obj-$(CONFIG_POSIX) += file-posix.o
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
new file mode 100644
index 0000000000..63bf6b34a9
--- /dev/null
+++ b/block/blklogwrites.c
@@ -0,0 +1,547 @@
+/*
+ * Write logging blk driver based on blkverify and blkdebug.
+ *
+ * Copyright (c) 2017 Tuomas Tynkkynen <tuomas@tuxera.com>
+ * Copyright (c) 2018 Aapo Vienamo <aapo@tuxera.com>
+ * Copyright (c) 2018 Ari Sundholm <ari@tuxera.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/sockets.h" /* for EINPROGRESS on Windows */
+#include "block/block_int.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
+#include "qemu/cutils.h"
+#include "qemu/option.h"
+
+/* Disk format stuff - taken from Linux drivers/md/dm-log-writes.c */
+
+#define LOG_FLUSH_FLAG   (1 << 0)
+#define LOG_FUA_FLAG     (1 << 1)
+#define LOG_DISCARD_FLAG (1 << 2)
+#define LOG_MARK_FLAG    (1 << 3)
+#define LOG_FLAG_MASK    (LOG_FLUSH_FLAG \
+                         | LOG_FUA_FLAG \
+                         | LOG_DISCARD_FLAG \
+                         | LOG_MARK_FLAG)
+
+#define WRITE_LOG_VERSION 1ULL
+#define WRITE_LOG_MAGIC 0x6a736677736872ULL
+
+/* All fields are little-endian. */
+struct log_write_super {
+    uint64_t magic;
+    uint64_t version;
+    uint64_t nr_entries;
+    uint32_t sectorsize;
+} QEMU_PACKED;
+
+struct log_write_entry {
+    uint64_t sector;
+    uint64_t nr_sectors;
+    uint64_t flags;
+    uint64_t data_len;
+} QEMU_PACKED;
+
+/* End of disk format structures. */
+
+typedef struct {
+    BdrvChild *log_file;
+    uint32_t sectorsize;
+    uint32_t sectorbits;
+    uint64_t cur_log_sector;
+    uint64_t nr_entries;
+    uint64_t update_interval;
+} BDRVBlkLogWritesState;
+
+static QemuOptsList runtime_opts = {
+    .name = "blklogwrites",
+    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
+    .desc = {
+        {
+            .name = "log-append",
+            .type = QEMU_OPT_BOOL,
+            .help = "Append to an existing log",
+        },
+        {
+            .name = "log-sector-size",
+            .type = QEMU_OPT_SIZE,
+            .help = "Log sector size",
+        },
+        {
+            .name = "log-super-update-interval",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Log superblock update interval (# of write requests)",
+        },
+        { /* end of list */ }
+    },
+};
+
+static inline uint32_t blk_log_writes_log2(uint32_t value)
+{
+    assert(value > 0);
+    return 31 - clz32(value);
+}
+
+static inline bool blk_log_writes_sector_size_valid(uint32_t sector_size)
+{
+    return sector_size < (1ull << 24) && is_power_of_2(sector_size);
+}
+
+static uint64_t blk_log_writes_find_cur_log_sector(BdrvChild *log,
+                                                   uint32_t sector_size,
+                                                   uint64_t nr_entries,
+                                                   Error **errp)
+{
+    uint64_t cur_sector = 1;
+    uint64_t cur_idx = 0;
+    uint32_t sector_bits = blk_log_writes_log2(sector_size);
+    struct log_write_entry cur_entry;
+
+    while (cur_idx < nr_entries) {
+        int read_ret = bdrv_pread(log, cur_sector << sector_bits, &cur_entry,
+                                  sizeof(cur_entry));
+        if (read_ret < 0) {
+            error_setg_errno(errp, -read_ret,
+                             "Failed to read log entry %"PRIu64, cur_idx);
+            return (uint64_t)-1ull;
+        }
+
+        if (cur_entry.flags & ~cpu_to_le64(LOG_FLAG_MASK)) {
+            error_setg(errp, "Invalid flags 0x%"PRIx64" in log entry %"PRIu64,
+                       le64_to_cpu(cur_entry.flags), cur_idx);
+            return (uint64_t)-1ull;
+        }
+
+        /* Account for the sector of the entry itself */
+        ++cur_sector;
+
+        /*
+         * Account for the data of the write.
+         * For discards, this data is not present.
+         */
+        if (!(cur_entry.flags & cpu_to_le64(LOG_DISCARD_FLAG))) {
+            cur_sector += le64_to_cpu(cur_entry.nr_sectors);
+        }
+
+        ++cur_idx;
+    }
+
+    return cur_sector;
+}
+
+static int blk_log_writes_open(BlockDriverState *bs, QDict *options, int flags,
+                               Error **errp)
+{
+    BDRVBlkLogWritesState *s = bs->opaque;
+    QemuOpts *opts;
+    Error *local_err = NULL;
+    int ret;
+    uint64_t log_sector_size;
+    bool log_append;
+
+    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (local_err) {
+        ret = -EINVAL;
+        error_propagate(errp, local_err);
+        goto fail;
+    }
+
+    /* Open the file */
+    bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false,
+                               &local_err);
+    if (local_err) {
+        ret = -EINVAL;
+        error_propagate(errp, local_err);
+        goto fail;
+    }
+
+    /* Open the log file */
+    s->log_file = bdrv_open_child(NULL, options, "log", bs, &child_file, false,
+                                  &local_err);
+    if (local_err) {
+        ret = -EINVAL;
+        error_propagate(errp, local_err);
+        goto fail;
+    }
+
+    log_append = qemu_opt_get_bool(opts, "log-append", false);
+
+    if (log_append) {
+        struct log_write_super log_sb = { 0, 0, 0, 0 };
+
+        if (qemu_opt_find(opts, "log-sector-size")) {
+            ret = -EINVAL;
+            error_setg(errp, "log-append and log-sector-size are mutually "
+                       "exclusive");
+            goto fail_log;
+        }
+
+        /* Read log superblock or fake one for an empty log */
+        if (!bdrv_getlength(s->log_file->bs)) {
+            log_sb.magic      = cpu_to_le64(WRITE_LOG_MAGIC);
+            log_sb.version    = cpu_to_le64(WRITE_LOG_VERSION);
+            log_sb.nr_entries = cpu_to_le64(0);
+            log_sb.sectorsize = cpu_to_le32(BDRV_SECTOR_SIZE);
+        } else {
+            ret = bdrv_pread(s->log_file, 0, &log_sb, sizeof(log_sb));
+            if (ret < 0) {
+                error_setg_errno(errp, -ret, "Could not read log superblock");
+                goto fail_log;
+            }
+        }
+
+        if (log_sb.magic != cpu_to_le64(WRITE_LOG_MAGIC)) {
+            ret = -EINVAL;
+            error_setg(errp, "Invalid log superblock magic");
+            goto fail_log;
+        }
+
+        if (log_sb.version != cpu_to_le64(WRITE_LOG_VERSION)) {
+            ret = -EINVAL;
+            error_setg(errp, "Unsupported log version %"PRIu64,
+                       le64_to_cpu(log_sb.version));
+            goto fail_log;
+        }
+
+        log_sector_size = le32_to_cpu(log_sb.sectorsize);
+        s->cur_log_sector = 1;
+        s->nr_entries = 0;
+
+        if (blk_log_writes_sector_size_valid(log_sector_size)) {
+            s->cur_log_sector =
+                blk_log_writes_find_cur_log_sector(s->log_file, log_sector_size,
+                                    le64_to_cpu(log_sb.nr_entries), &local_err);
+            if (local_err) {
+                ret = -EINVAL;
+                error_propagate(errp, local_err);
+                goto fail_log;
+            }
+
+            s->nr_entries = le64_to_cpu(log_sb.nr_entries);
+        }
+    } else {
+        log_sector_size = qemu_opt_get_size(opts, "log-sector-size",
+                                            BDRV_SECTOR_SIZE);
+        s->cur_log_sector = 1;
+        s->nr_entries = 0;
+    }
+
+    if (!blk_log_writes_sector_size_valid(log_sector_size)) {
+        ret = -EINVAL;
+        error_setg(errp, "Invalid log sector size %"PRIu64, log_sector_size);
+        goto fail_log;
+    }
+
+    s->sectorsize = log_sector_size;
+    s->sectorbits = blk_log_writes_log2(log_sector_size);
+    s->update_interval = qemu_opt_get_number(opts, "log-super-update-interval",
+                                             4096);
+    if (!s->update_interval) {
+        ret = -EINVAL;
+        error_setg(errp, "Invalid log superblock update interval %"PRIu64,
+                   s->update_interval);
+        goto fail_log;
+    }
+
+    ret = 0;
+fail_log:
+    if (ret < 0) {
+        bdrv_unref_child(bs, s->log_file);
+        s->log_file = NULL;
+    }
+fail:
+    if (ret < 0) {
+        bdrv_unref_child(bs, bs->file);
+        bs->file = NULL;
+    }
+    qemu_opts_del(opts);
+    return ret;
+}
+
+static void blk_log_writes_close(BlockDriverState *bs)
+{
+    BDRVBlkLogWritesState *s = bs->opaque;
+
+    bdrv_unref_child(bs, s->log_file);
+    s->log_file = NULL;
+}
+
+static int64_t blk_log_writes_getlength(BlockDriverState *bs)
+{
+    return bdrv_getlength(bs->file->bs);
+}
+
+static void blk_log_writes_refresh_filename(BlockDriverState *bs,
+                                            QDict *options)
+{
+    BDRVBlkLogWritesState *s = bs->opaque;
+
+    /* bs->file->bs has already been refreshed */
+    bdrv_refresh_filename(s->log_file->bs);
+
+    if (bs->file->bs->full_open_options
+        && s->log_file->bs->full_open_options)
+    {
+        QDict *opts = qdict_new();
+        qdict_put_str(opts, "driver", "blklogwrites");
+
+        qobject_ref(bs->file->bs->full_open_options);
+        qdict_put_obj(opts, "file", QOBJECT(bs->file->bs->full_open_options));
+        qobject_ref(s->log_file->bs->full_open_options);
+        qdict_put_obj(opts, "log",
+                      QOBJECT(s->log_file->bs->full_open_options));
+        qdict_put_int(opts, "log-sector-size", s->sectorsize);
+
+        bs->full_open_options = opts;
+    }
+}
+
+static void blk_log_writes_child_perm(BlockDriverState *bs, BdrvChild *c,
+                                      const BdrvChildRole *role,
+                                      BlockReopenQueue *ro_q,
+                                      uint64_t perm, uint64_t shrd,
+                                      uint64_t *nperm, uint64_t *nshrd)
+{
+    if (!c) {
+        *nperm = perm & DEFAULT_PERM_PASSTHROUGH;
+        *nshrd = (shrd & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
+        return;
+    }
+
+    if (!strcmp(c->name, "log")) {
+        bdrv_format_default_perms(bs, c, role, ro_q, perm, shrd, nperm, nshrd);
+    } else {
+        bdrv_filter_default_perms(bs, c, role, ro_q, perm, shrd, nperm, nshrd);
+    }
+}
+
+static void blk_log_writes_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    BDRVBlkLogWritesState *s = bs->opaque;
+    bs->bl.request_alignment = s->sectorsize;
+}
+
+static int coroutine_fn
+blk_log_writes_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+                         QEMUIOVector *qiov, int flags)
+{
+    return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
+}
+
+typedef struct BlkLogWritesFileReq {
+    BlockDriverState *bs;
+    uint64_t offset;
+    uint64_t bytes;
+    int file_flags;
+    QEMUIOVector *qiov;
+    int (*func)(struct BlkLogWritesFileReq *r);
+    int file_ret;
+} BlkLogWritesFileReq;
+
+typedef struct {
+    BlockDriverState *bs;
+    QEMUIOVector *qiov;
+    struct log_write_entry entry;
+    uint64_t zero_size;
+    int log_ret;
+} BlkLogWritesLogReq;
+
+static void coroutine_fn blk_log_writes_co_do_log(BlkLogWritesLogReq *lr)
+{
+    BDRVBlkLogWritesState *s = lr->bs->opaque;
+    uint64_t cur_log_offset = s->cur_log_sector << s->sectorbits;
+
+    s->nr_entries++;
+    s->cur_log_sector +=
+            ROUND_UP(lr->qiov->size, s->sectorsize) >> s->sectorbits;
+
+    lr->log_ret = bdrv_co_pwritev(s->log_file, cur_log_offset, lr->qiov->size,
+                                  lr->qiov, 0);
+
+    /* Logging for the "write zeroes" operation */
+    if (lr->log_ret == 0 && lr->zero_size) {
+        cur_log_offset = s->cur_log_sector << s->sectorbits;
+        s->cur_log_sector +=
+                ROUND_UP(lr->zero_size, s->sectorsize) >> s->sectorbits;
+
+        lr->log_ret = bdrv_co_pwrite_zeroes(s->log_file, cur_log_offset,
+                                            lr->zero_size, 0);
+    }
+
+    /* Update super block on flush or every update interval */
+    if (lr->log_ret == 0 && ((lr->entry.flags & LOG_FLUSH_FLAG)
+        || (s->nr_entries % s->update_interval == 0)))
+    {
+        struct log_write_super super = {
+            .magic      = cpu_to_le64(WRITE_LOG_MAGIC),
+            .version    = cpu_to_le64(WRITE_LOG_VERSION),
+            .nr_entries = cpu_to_le64(s->nr_entries),
+            .sectorsize = cpu_to_le32(s->sectorsize),
+        };
+        void *zeroes = g_malloc0(s->sectorsize - sizeof(super));
+        QEMUIOVector qiov;
+
+        qemu_iovec_init(&qiov, 2);
+        qemu_iovec_add(&qiov, &super, sizeof(super));
+        qemu_iovec_add(&qiov, zeroes, s->sectorsize - sizeof(super));
+
+        lr->log_ret =
+            bdrv_co_pwritev(s->log_file, 0, s->sectorsize, &qiov, 0);
+        if (lr->log_ret == 0) {
+            lr->log_ret = bdrv_co_flush(s->log_file->bs);
+        }
+        qemu_iovec_destroy(&qiov);
+        g_free(zeroes);
+    }
+}
+
+static void coroutine_fn blk_log_writes_co_do_file(BlkLogWritesFileReq *fr)
+{
+    fr->file_ret = fr->func(fr);
+}
+
+static int coroutine_fn
+blk_log_writes_co_log(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+                      QEMUIOVector *qiov, int flags,
+                      int (*file_func)(BlkLogWritesFileReq *r),
+                      uint64_t entry_flags, bool is_zero_write)
+{
+    QEMUIOVector log_qiov;
+    size_t niov = qiov ? qiov->niov : 0;
+    BDRVBlkLogWritesState *s = bs->opaque;
+    BlkLogWritesFileReq fr = {
+        .bs         = bs,
+        .offset     = offset,
+        .bytes      = bytes,
+        .file_flags = flags,
+        .qiov       = qiov,
+        .func       = file_func,
+    };
+    BlkLogWritesLogReq lr = {
+        .bs             = bs,
+        .qiov           = &log_qiov,
+        .entry = {
+            .sector     = cpu_to_le64(offset >> s->sectorbits),
+            .nr_sectors = cpu_to_le64(bytes >> s->sectorbits),
+            .flags      = cpu_to_le64(entry_flags),
+            .data_len   = 0,
+        },
+        .zero_size = is_zero_write ? bytes : 0,
+    };
+    void *zeroes = g_malloc0(s->sectorsize - sizeof(lr.entry));
+
+    assert((1 << s->sectorbits) == s->sectorsize);
+    assert(bs->bl.request_alignment == s->sectorsize);
+    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
+    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
+
+    qemu_iovec_init(&log_qiov, niov + 2);
+    qemu_iovec_add(&log_qiov, &lr.entry, sizeof(lr.entry));
+    qemu_iovec_add(&log_qiov, zeroes, s->sectorsize - sizeof(lr.entry));
+    if (qiov) {
+        qemu_iovec_concat(&log_qiov, qiov, 0, qiov->size);
+    }
+
+    blk_log_writes_co_do_file(&fr);
+    blk_log_writes_co_do_log(&lr);
+
+    qemu_iovec_destroy(&log_qiov);
+    g_free(zeroes);
+
+    if (lr.log_ret < 0) {
+        return lr.log_ret;
+    }
+
+    return fr.file_ret;
+}
+
+static int coroutine_fn
+blk_log_writes_co_do_file_pwritev(BlkLogWritesFileReq *fr)
+{
+    return bdrv_co_pwritev(fr->bs->file, fr->offset, fr->bytes,
+                           fr->qiov, fr->file_flags);
+}
+
+static int coroutine_fn
+blk_log_writes_co_do_file_pwrite_zeroes(BlkLogWritesFileReq *fr)
+{
+    return bdrv_co_pwrite_zeroes(fr->bs->file, fr->offset, fr->bytes,
+                                 fr->file_flags);
+}
+
+static int coroutine_fn blk_log_writes_co_do_file_flush(BlkLogWritesFileReq *fr)
+{
+    return bdrv_co_flush(fr->bs->file->bs);
+}
+
+static int coroutine_fn
+blk_log_writes_co_do_file_pdiscard(BlkLogWritesFileReq *fr)
+{
+    return bdrv_co_pdiscard(fr->bs->file->bs, fr->offset, fr->bytes);
+}
+
+static int coroutine_fn
+blk_log_writes_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
+                          QEMUIOVector *qiov, int flags)
+{
+    return blk_log_writes_co_log(bs, offset, bytes, qiov, flags,
+                                 blk_log_writes_co_do_file_pwritev, 0, false);
+}
+
+static int coroutine_fn
+blk_log_writes_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
+                                BdrvRequestFlags flags)
+{
+    return blk_log_writes_co_log(bs, offset, bytes, NULL, flags,
+                                 blk_log_writes_co_do_file_pwrite_zeroes, 0,
+                                 true);
+}
+
+static int coroutine_fn blk_log_writes_co_flush_to_disk(BlockDriverState *bs)
+{
+    return blk_log_writes_co_log(bs, 0, 0, NULL, 0,
+                                 blk_log_writes_co_do_file_flush,
+                                 LOG_FLUSH_FLAG, false);
+}
+
+static int coroutine_fn
+blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
+{
+    return blk_log_writes_co_log(bs, offset, count, NULL, 0,
+                                 blk_log_writes_co_do_file_pdiscard,
+                                 LOG_DISCARD_FLAG, false);
+}
+
+static BlockDriver bdrv_blk_log_writes = {
+    .format_name            = "blklogwrites",
+    .instance_size          = sizeof(BDRVBlkLogWritesState),
+
+    .bdrv_open              = blk_log_writes_open,
+    .bdrv_close             = blk_log_writes_close,
+    .bdrv_getlength         = blk_log_writes_getlength,
+    .bdrv_refresh_filename  = blk_log_writes_refresh_filename,
+    .bdrv_child_perm        = blk_log_writes_child_perm,
+    .bdrv_refresh_limits    = blk_log_writes_refresh_limits,
+
+    .bdrv_co_preadv         = blk_log_writes_co_preadv,
+    .bdrv_co_pwritev        = blk_log_writes_co_pwritev,
+    .bdrv_co_pwrite_zeroes  = blk_log_writes_co_pwrite_zeroes,
+    .bdrv_co_flush_to_disk  = blk_log_writes_co_flush_to_disk,
+    .bdrv_co_pdiscard       = blk_log_writes_co_pdiscard,
+    .bdrv_co_block_status   = bdrv_co_block_status_from_file,
+
+    .is_filter              = true,
+};
+
+static void bdrv_blk_log_writes_init(void)
+{
+    bdrv_register(&bdrv_blk_log_writes);
+}
+
+block_init(bdrv_blk_log_writes_init);
diff --git a/block/crypto.c b/block/crypto.c
index 994172a3de..146d81c90a 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -551,7 +551,7 @@ static int coroutine_fn block_crypto_co_create_opts_luks(const char *filename,
     /* Create protocol layer */
     ret = bdrv_create_file(filename, opts, errp);
     if (ret < 0) {
-        return ret;
+        goto fail;
     }
 
     bs = bdrv_open(filename, NULL, NULL,
diff --git a/block/file-posix.c b/block/file-posix.c
index 829ee538d8..98987b80f1 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2111,8 +2111,9 @@ static int coroutine_fn
 raw_co_create(BlockdevCreateOptions *options, Error **errp)
 {
     BlockdevCreateOptionsFile *file_opts;
+    Error *local_err = NULL;
     int fd;
-    int perm, shared;
+    uint64_t perm, shared;
     int result = 0;
 
     /* Validate options and set default values */
@@ -2148,7 +2149,7 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
     shared = BLK_PERM_ALL & ~BLK_PERM_RESIZE;
 
     /* Step one: Take locks */
-    result = raw_apply_lock_bytes(fd, perm, shared, false, errp);
+    result = raw_apply_lock_bytes(fd, perm, ~shared, false, errp);
     if (result < 0) {
         goto out_close;
     }
@@ -2156,13 +2157,13 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
     /* Step two: Check that nobody else has taken conflicting locks */
     result = raw_check_lock_bytes(fd, perm, shared, errp);
     if (result < 0) {
-        goto out_close;
+        goto out_unlock;
     }
 
     /* Clear the file by truncating it to 0 */
     result = raw_regular_truncate(NULL, fd, 0, PREALLOC_MODE_OFF, errp);
     if (result < 0) {
-        goto out_close;
+        goto out_unlock;
     }
 
     if (file_opts->nocow) {
@@ -2185,7 +2186,17 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
     result = raw_regular_truncate(NULL, fd, file_opts->size,
                                   file_opts->preallocation, errp);
     if (result < 0) {
-        goto out_close;
+        goto out_unlock;
+    }
+
+out_unlock:
+    raw_apply_lock_bytes(fd, 0, 0, true, &local_err);
+    if (local_err) {
+        /* The above call should not fail, and if it does, that does
+         * not mean the whole creation operation has failed.  So
+         * report it the user for their convenience, but do not report
+         * it to the caller. */
+        error_report_err(local_err);
     }
 
 out_close:
diff --git a/block/qcow2.c b/block/qcow2.c
index 2f9e58e0c4..33b61b7480 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -23,11 +23,14 @@
  */
 
 #include "qemu/osdep.h"
+
+#define ZLIB_CONST
+#include <zlib.h>
+
 #include "block/block_int.h"
 #include "block/qdict.h"
 #include "sysemu/block-backend.h"
 #include "qemu/module.h"
-#include <zlib.h>
 #include "qcow2.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
@@ -41,6 +44,7 @@
 #include "qapi/qobject-input-visitor.h"
 #include "qapi/qapi-visit-block-core.h"
 #include "crypto.h"
+#include "block/thread-pool.h"
 
 /*
   Differences with QCOW:
@@ -1541,6 +1545,9 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
         qcow2_check_refcounts(bs, &result, 0);
     }
 #endif
+
+    qemu_co_queue_init(&s->compress_wait_queue);
+
     return ret;
 
  fail:
@@ -3650,6 +3657,104 @@ fail:
     return ret;
 }
 
+/*
+ * qcow2_compress()
+ *
+ * @dest - destination buffer, at least of @size-1 bytes
+ * @src - source buffer, @size bytes
+ *
+ * Returns: compressed size on success
+ *          -1 if compression is inefficient
+ *          -2 on any other error
+ */
+static ssize_t qcow2_compress(void *dest, const void *src, size_t size)
+{
+    ssize_t ret;
+    z_stream strm;
+
+    /* best compression, small window, no zlib header */
+    memset(&strm, 0, sizeof(strm));
+    ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+                       -12, 9, Z_DEFAULT_STRATEGY);
+    if (ret != 0) {
+        return -2;
+    }
+
+    /* strm.next_in is not const in old zlib versions, such as those used on
+     * OpenBSD/NetBSD, so cast the const away */
+    strm.avail_in = size;
+    strm.next_in = (void *) src;
+    strm.avail_out = size - 1;
+    strm.next_out = dest;
+
+    ret = deflate(&strm, Z_FINISH);
+    if (ret == Z_STREAM_END) {
+        ret = size - 1 - strm.avail_out;
+    } else {
+        ret = (ret == Z_OK ? -1 : -2);
+    }
+
+    deflateEnd(&strm);
+
+    return ret;
+}
+
+#define MAX_COMPRESS_THREADS 4
+
+typedef struct Qcow2CompressData {
+    void *dest;
+    const void *src;
+    size_t size;
+    ssize_t ret;
+} Qcow2CompressData;
+
+static int qcow2_compress_pool_func(void *opaque)
+{
+    Qcow2CompressData *data = opaque;
+
+    data->ret = qcow2_compress(data->dest, data->src, data->size);
+
+    return 0;
+}
+
+static void qcow2_compress_complete(void *opaque, int ret)
+{
+    qemu_coroutine_enter(opaque);
+}
+
+/* See qcow2_compress definition for parameters description */
+static ssize_t qcow2_co_compress(BlockDriverState *bs,
+                                 void *dest, const void *src, size_t size)
+{
+    BDRVQcow2State *s = bs->opaque;
+    BlockAIOCB *acb;
+    ThreadPool *pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
+    Qcow2CompressData arg = {
+        .dest = dest,
+        .src = src,
+        .size = size,
+    };
+
+    while (s->nb_compress_threads >= MAX_COMPRESS_THREADS) {
+        qemu_co_queue_wait(&s->compress_wait_queue, NULL);
+    }
+
+    s->nb_compress_threads++;
+    acb = thread_pool_submit_aio(pool, qcow2_compress_pool_func, &arg,
+                                 qcow2_compress_complete,
+                                 qemu_coroutine_self());
+
+    if (!acb) {
+        s->nb_compress_threads--;
+        return -EINVAL;
+    }
+    qemu_coroutine_yield();
+    s->nb_compress_threads--;
+    qemu_co_queue_next(&s->compress_wait_queue);
+
+    return arg.ret;
+}
+
 /* XXX: put compressed sectors first, then all the cluster aligned
    tables to avoid losing bytes in alignment */
 static coroutine_fn int
@@ -3659,8 +3764,8 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     BDRVQcow2State *s = bs->opaque;
     QEMUIOVector hd_qiov;
     struct iovec iov;
-    z_stream strm;
-    int ret, out_len;
+    int ret;
+    size_t out_len;
     uint8_t *buf, *out_buf;
     int64_t cluster_offset;
 
@@ -3694,32 +3799,11 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
 
     out_buf = g_malloc(s->cluster_size);
 
-    /* best compression, small window, no zlib header */
-    memset(&strm, 0, sizeof(strm));
-    ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
-                       Z_DEFLATED, -12,
-                       9, Z_DEFAULT_STRATEGY);
-    if (ret != 0) {
+    out_len = qcow2_co_compress(bs, out_buf, buf, s->cluster_size);
+    if (out_len == -2) {
         ret = -EINVAL;
         goto fail;
-    }
-
-    strm.avail_in = s->cluster_size;
-    strm.next_in = (uint8_t *)buf;
-    strm.avail_out = s->cluster_size;
-    strm.next_out = out_buf;
-
-    ret = deflate(&strm, Z_FINISH);
-    if (ret != Z_STREAM_END && ret != Z_OK) {
-        deflateEnd(&strm);
-        ret = -EINVAL;
-        goto fail;
-    }
-    out_len = strm.next_out - out_buf;
-
-    deflateEnd(&strm);
-
-    if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
+    } else if (out_len == -1) {
         /* could not compress: write normal cluster */
         ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0);
         if (ret < 0) {
diff --git a/block/qcow2.h b/block/qcow2.h
index 1c9c0d3631..d6aca687d6 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -326,6 +326,9 @@ typedef struct BDRVQcow2State {
      * override) */
     char *image_backing_file;
     char *image_backing_format;
+
+    CoQueue compress_wait_queue;
+    int nb_compress_threads;
 } BDRVQcow2State;
 
 typedef struct Qcow2COWRegion {