From f2add7d5955770318824c3eee774bec2dd850936 Mon Sep 17 00:00:00 2001

From: Eric Blake <eblake@redhat.com>

Date: Tue, 2 Jun 2020 02:34:19 +0100

Subject: [PATCH 14/26] qemu-img: Add convert --bitmaps option

RH-Author: Eric Blake <eblake@redhat.com>

Message-id: <20200602023420.2133649-12-eblake@redhat.com>

Patchwork-id: 97076

O-Subject: [RHEL-AV-8.2.1 qemu-kvm PATCH 11/12] qemu-img: Add convert --bitmaps option

Bugzilla: 1779893 1779904

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Max Reitz <mreitz@redhat.com>

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

Make it easier to copy all the persistent bitmaps of (the top layer

of) a source image along with its guest-visible contents, by adding a

boolean flag for use with qemu-img convert.  This is basically

shorthand, as the same effect could be accomplished with a series of

'qemu-img bitmap --add' and 'qemu-img bitmap --merge -b source'

commands, or by their corresponding QMP commands.

Note that this command will fail in the same scenarios where 'qemu-img

measure' omits a 'bitmaps size:' line, namely, when either the source

or the destination lacks persistent bitmap support altogether.

See also https://bugzilla.redhat.com/show_bug.cgi?id=1779893

While touching this, clean up a couple coding issues spotted in the

same function: an extra blank line, and merging back-to-back 'if

(!skip_create)' blocks.

Signed-off-by: Eric Blake <eblake@redhat.com>

Message-Id: <20200521192137.1120211-5-eblake@redhat.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

(cherry picked from commit 15e39ad95078d528dfb9a75417453cab60332b77)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

Conflicts:

	docs/tools/qemu-img.rst - qemu-img.texi instead

	qemu-img.c - context: no --target-is-zero

	qemu-img-cmds.hx - context: texi instead of rst

Signed-off-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 qemu-img-cmds.hx |  4 ++--

 qemu-img.c       | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++---

 qemu-img.texi    |  4 +++-

 3 files changed, 72 insertions(+), 6 deletions(-)

diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx

index 1a6a8e9..48144aa 100644

--- a/qemu-img-cmds.hx

+++ b/qemu-img-cmds.hx

@@ -50,9 +50,9 @@ STEXI

 ETEXI

 DEF("convert", img_convert,

-    "convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")

+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")

 STEXI

-@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] [--salvage] @var{filename} [@var{filename2} [...]] @var{output_filename}

+@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] [--salvage] @var{filename} [@var{filename2} [...]] @var{output_filename}

 ETEXI

 DEF("create", img_create,

diff --git a/qemu-img.c b/qemu-img.c

index 39e1586..6dc881b 100644

--- a/qemu-img.c

+++ b/qemu-img.c

@@ -77,6 +77,7 @@ enum {

     OPTION_ENABLE = 272,

     OPTION_DISABLE = 273,

     OPTION_MERGE = 274,

+    OPTION_BITMAPS = 275,

 };

 typedef enum OutputFormat {

@@ -190,6 +191,7 @@ static void QEMU_NORETURN help(void)

            "       hiding corruption that has already occurred.\n"

            "\n"

            "Parameters to convert subcommand:\n"

+           "  '--bitmaps' copies all top-level persistent bitmaps to destination\n"

            "  '-m' specifies how many coroutines work in parallel during the convert\n"

            "       process (defaults to 8)\n"

            "  '-W' allow to write to the target out of order rather than sequential\n"

@@ -2084,6 +2086,39 @@ static int convert_do_copy(ImgConvertState *s)

     return s->ret;

 }

+static int convert_copy_bitmaps(BlockDriverState *src, BlockDriverState *dst)

+{

+    BdrvDirtyBitmap *bm;

+    Error *err = NULL;

+

+    FOR_EACH_DIRTY_BITMAP(src, bm) {

+        const char *name;

+

+        if (!bdrv_dirty_bitmap_get_persistence(bm)) {

+            continue;

+        }

+        name = bdrv_dirty_bitmap_name(bm);

+        qmp_block_dirty_bitmap_add(dst->node_name, name,

+                                   true, bdrv_dirty_bitmap_granularity(bm),

+                                   true, true,

+                                   true, !bdrv_dirty_bitmap_enabled(bm),

+                                   &err;;

+        if (err) {

+            error_reportf_err(err, "Failed to create bitmap %s: ", name);

+            return -1;

+        }

+

+        do_dirty_bitmap_merge(dst->node_name, name, src->node_name, name,

+                              &err;;

+        if (err) {

+            error_reportf_err(err, "Failed to populate bitmap %s: ", name);

+            return -1;

+        }

+    }

+

+    return 0;

+}

+

 #define MAX_BUF_SECTORS 32768

 static int img_convert(int argc, char **argv)

@@ -2105,6 +2140,7 @@ static int img_convert(int argc, char **argv)

     int64_t ret = -EINVAL;

     bool force_share = false;

     bool explict_min_sparse = false;

+    bool bitmaps = false;

     ImgConvertState s = (ImgConvertState) {

         /* Need at least 4k of zeros for sparse detection */

@@ -2123,6 +2159,7 @@ static int img_convert(int argc, char **argv)

             {"force-share", no_argument, 0, 'U'},

             {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},

             {"salvage", no_argument, 0, OPTION_SALVAGE},

+            {"bitmaps", no_argument, 0, OPTION_BITMAPS},

             {0, 0, 0, 0}

         };

         c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WU",

@@ -2248,6 +2285,9 @@ static int img_convert(int argc, char **argv)

         case OPTION_TARGET_IMAGE_OPTS:

             tgt_image_opts = true;

             break;

+        case OPTION_BITMAPS:

+            bitmaps = true;

+            break;

         }

     }

@@ -2304,7 +2344,6 @@ static int img_convert(int argc, char **argv)

         goto fail_getopt;

     }

-

     /* ret is still -EINVAL until here */

     ret = bdrv_parse_cache_mode(src_cache, &src_flags, &src_writethrough);

     if (ret < 0) {

@@ -2458,6 +2497,20 @@ static int img_convert(int argc, char **argv)

         }

     }

+    /* Determine if bitmaps need copying */

+    if (bitmaps) {

+        if (s.src_num > 1) {

+            error_report("Copying bitmaps only possible with single source");

+            ret = -1;

+            goto out;

+        }

+        if (!bdrv_supports_persistent_dirty_bitmap(blk_bs(s.src[0]))) {

+            error_report("Source lacks bitmap support");

+            ret = -1;

+            goto out;

+        }

+    }

+

     /*

      * The later open call will need any decryption secrets, and

      * bdrv_create() will purge "opts", so extract them now before

@@ -2466,9 +2519,7 @@ static int img_convert(int argc, char **argv)

     if (!skip_create) {

         open_opts = qdict_new();

         qemu_opt_foreach(opts, img_add_key_secrets, open_opts, &error_abort);

-    }

-    if (!skip_create) {

         /* Create the new image */

         ret = bdrv_create(drv, out_filename, opts, &local_err);

         if (ret < 0) {

@@ -2506,6 +2557,13 @@ static int img_convert(int argc, char **argv)

     }

     out_bs = blk_bs(s.target);

+    if (bitmaps && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {

+        error_report("Format driver '%s' does not support bitmaps",

+                     out_bs->drv->format_name);

+        ret = -1;

+        goto out;

+    }

+

     if (s.compressed && !block_driver_can_compress(out_bs->drv)) {

         error_report("Compression not supported for this file format");

         ret = -1;

@@ -2565,6 +2623,12 @@ static int img_convert(int argc, char **argv)

     }

     ret = convert_do_copy(&s);

+

+    /* Now copy the bitmaps */

+    if (bitmaps && ret == 0) {

+        ret = convert_copy_bitmaps(blk_bs(s.src[0]), out_bs);

+    }

+

 out:

     if (!ret) {

         qemu_progress_print(100, 0);

diff --git a/qemu-img.texi b/qemu-img.texi

index 3670b96..b95d019 100644

--- a/qemu-img.texi

+++ b/qemu-img.texi

@@ -161,6 +161,8 @@ Parameters to convert subcommand:

 @table @option

+@item --bitmaps

+Additionally copy all persistent bitmaps from the top layer of the source

 @item -n

 Skip the creation of the target volume

 @item -m

@@ -357,7 +359,7 @@ Error on reading data

 @end table

-@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}

+@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}

 Convert the disk image @var{filename} or a snapshot @var{snapshot_param}

 to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c}

-- 

1.8.3.1