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>
---
docs/tools/qemu-img.rst | 6 +++-
qemu-img.c | 78 +++++++++++++++++++++++++++++++++++++++--
qemu-img-cmds.hx | 4 +--
3 files changed, 82 insertions(+), 6 deletions(-)
diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
index 320cb52b9f61..69cd9a30373a 100644
--- a/docs/tools/qemu-img.rst
+++ b/docs/tools/qemu-img.rst
@@ -162,6 +162,10 @@ Parameters to convert subcommand:
.. program:: qemu-img-convert
+.. option:: --bitmaps
+
+ Additionally copy all persistent bitmaps from the top layer of the source
+
.. option:: -n
Skip the creation of the target volume
@@ -397,7 +401,7 @@ Command description:
4
Error on reading data
-.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [-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] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
+.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--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] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
Convert the disk image *FILENAME* or a snapshot *SNAPSHOT_PARAM*
to disk image *OUTPUT_FILENAME* using format *OUTPUT_FMT*. It can
diff --git a/qemu-img.c b/qemu-img.c
index 0778d8f56614..8ecebe178890 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -78,6 +78,7 @@ enum {
OPTION_ENABLE = 272,
OPTION_DISABLE = 273,
OPTION_MERGE = 274,
+ OPTION_BITMAPS = 275,
};
typedef enum OutputFormat {
@@ -191,6 +192,7 @@ 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"
@@ -2139,6 +2141,39 @@ 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)
@@ -2160,6 +2195,8 @@ static int img_convert(int argc, char **argv)
int64_t ret = -EINVAL;
bool force_share = false;
bool explict_min_sparse = false;
+ bool bitmaps = false;
+ size_t nbitmaps = 0;
ImgConvertState s = (ImgConvertState) {
/* Need at least 4k of zeros for sparse detection */
@@ -2179,6 +2216,7 @@ static int img_convert(int argc, char **argv)
{"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
{"salvage", no_argument, 0, OPTION_SALVAGE},
{"target-is-zero", no_argument, 0, OPTION_TARGET_IS_ZERO},
+ {"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",
@@ -2304,6 +2342,9 @@ static int img_convert(int argc, char **argv)
*/
s.has_zero_init = true;
break;
+ case OPTION_BITMAPS:
+ bitmaps = true;
+ break;
}
}
@@ -2365,7 +2406,6 @@ 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) {
@@ -2525,6 +2565,27 @@ static int img_convert(int argc, char **argv)
}
}
+ /* Determine how many bitmaps need copying */
+ if (bitmaps) {
+ BdrvDirtyBitmap *bm;
+
+ 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;
+ }
+ FOR_EACH_DIRTY_BITMAP(blk_bs(s.src[0]), bm) {
+ if (bdrv_dirty_bitmap_get_persistence(bm)) {
+ nbitmaps++;
+ }
+ }
+ }
+
/*
* The later open call will need any decryption secrets, and
* bdrv_create() will purge "opts", so extract them now before
@@ -2533,9 +2594,7 @@ 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) {
@@ -2573,6 +2632,13 @@ static int img_convert(int argc, char **argv)
}
out_bs = blk_bs(s.target);
+ if (nbitmaps > 0 && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
+ error_report("Format driver '%s' does not support bitmaps",
+ out_fmt);
+ 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;
@@ -2632,6 +2698,12 @@ static int img_convert(int argc, char **argv)
}
ret = convert_do_copy(&s);
+
+ /* Now copy the bitmaps */
+ if (nbitmaps > 0 && 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-cmds.hx b/qemu-img-cmds.hx
index a87d3cb264ce..10b910b67cf8 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -46,9 +46,9 @@ SRST
ERST
DEF("convert", img_convert,
- "convert [--object objectdef] [--image-opts] [--target-image-opts] [--target-is-zero] [-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] [--target-is-zero] [--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")
SRST
-.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [-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
+.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--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
ERST
DEF("create", img_create,
--
2.26.2
21.05.2020 22:21, Eric Blake wrote:
> 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>
> ---
[..]
> diff --git a/qemu-img.c b/qemu-img.c
> index 0778d8f56614..8ecebe178890 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -78,6 +78,7 @@ enum {
> OPTION_ENABLE = 272,
> OPTION_DISABLE = 273,
> OPTION_MERGE = 274,
[..]
>
> static int img_convert(int argc, char **argv)
> @@ -2160,6 +2195,8 @@ static int img_convert(int argc, char **argv)
> int64_t ret = -EINVAL;
> bool force_share = false;
> bool explict_min_sparse = false;
> + bool bitmaps = false;
> + size_t nbitmaps = 0;
>
> ImgConvertState s = (ImgConvertState) {
> /* Need at least 4k of zeros for sparse detection */
> @@ -2179,6 +2216,7 @@ static int img_convert(int argc, char **argv)
> {"target-image-opts", no_argument, 0, OPTION_TARGET_IMAGE_OPTS},
> {"salvage", no_argument, 0, OPTION_SALVAGE},
> {"target-is-zero", no_argument, 0, OPTION_TARGET_IS_ZERO},
> + {"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",
> @@ -2304,6 +2342,9 @@ static int img_convert(int argc, char **argv)
> */
> s.has_zero_init = true;
> break;
> + case OPTION_BITMAPS:
> + bitmaps = true;
> + break;
> }
> }
>
> @@ -2365,7 +2406,6 @@ 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) {
> @@ -2525,6 +2565,27 @@ static int img_convert(int argc, char **argv)
> }
> }
>
> + /* Determine how many bitmaps need copying */
> + if (bitmaps) {
> + BdrvDirtyBitmap *bm;
> +
> + 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;
> + }
> + FOR_EACH_DIRTY_BITMAP(blk_bs(s.src[0]), bm) {
> + if (bdrv_dirty_bitmap_get_persistence(bm)) {
> + nbitmaps++;
> + }
> + }
> + }
> +
> /*
> * The later open call will need any decryption secrets, and
> * bdrv_create() will purge "opts", so extract them now before
> @@ -2533,9 +2594,7 @@ 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) {
> @@ -2573,6 +2632,13 @@ static int img_convert(int argc, char **argv)
> }
> out_bs = blk_bs(s.target);
>
> + if (nbitmaps > 0 && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
We will not fail, if target doesn't support bitmaps, source supports them but has no bitmaps? Doesn't seem to be a problem, but a bit less strict than you write in commit message.
So, maybe, s/nbitmaps > 0/bitmaps/
> + error_report("Format driver '%s' does not support bitmaps",
> + out_fmt);
Hmm seems, out_fmt may be NULL at this point, consider the path:
const char *out_fmt = NULL
...
[no -O option]
--target-image-opts, so out_fmt doesn't default to "raw" but remains NULL
...
So, with s/out_fmt/out_bs->drv->format_name/ (and with or without s/nbitmaps > 0/bitmaps/):
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
--
Best regards,
Vladimir
On 5/25/20 2:51 AM, Vladimir Sementsov-Ogievskiy wrote:
> 21.05.2020 22:21, Eric Blake wrote:
>> 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>
>> ---
>
>> @@ -2573,6 +2632,13 @@ static int img_convert(int argc, char **argv)
>> }
>> out_bs = blk_bs(s.target);
>>
>> + if (nbitmaps > 0 &&
>> !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
>
> We will not fail, if target doesn't support bitmaps, source supports
> them but has no bitmaps? Doesn't seem to be a problem, but a bit less
> strict than you write in commit message.
>
> So, maybe, s/nbitmaps > 0/bitmaps/
In fact, nbitmaps is not needed at all (it was useful in earlier
iterations, but as the series has morphed, it is no longer buying me
anything useful).
>
>> + error_report("Format driver '%s' does not support bitmaps",
>> + out_fmt);
>
> Hmm seems, out_fmt may be NULL at this point, consider the path:
> const char *out_fmt = NULL
> ...
> [no -O option]
> --target-image-opts, so out_fmt doesn't default to "raw" but remains NULL
> ...
>
> So, with s/out_fmt/out_bs->drv->format_name/ (and with or without
> s/nbitmaps > 0/bitmaps/):
>
>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Okay, I'm squashing this in, and adding your R-b. Pull request coming
shortly.
diff --git i/qemu-img.c w/qemu-img.c
index 8ecebe178890..d7e846e60742 100644
--- i/qemu-img.c
+++ w/qemu-img.c
@@ -2196,7 +2196,6 @@ static int img_convert(int argc, char **argv)
bool force_share = false;
bool explict_min_sparse = false;
bool bitmaps = false;
- size_t nbitmaps = 0;
ImgConvertState s = (ImgConvertState) {
/* Need at least 4k of zeros for sparse detection */
@@ -2565,10 +2564,8 @@ static int img_convert(int argc, char **argv)
}
}
- /* Determine how many bitmaps need copying */
+ /* Determine if bitmaps need copying */
if (bitmaps) {
- BdrvDirtyBitmap *bm;
-
if (s.src_num > 1) {
error_report("Copying bitmaps only possible with single
source");
ret = -1;
@@ -2579,11 +2576,6 @@ static int img_convert(int argc, char **argv)
ret = -1;
goto out;
}
- FOR_EACH_DIRTY_BITMAP(blk_bs(s.src[0]), bm) {
- if (bdrv_dirty_bitmap_get_persistence(bm)) {
- nbitmaps++;
- }
- }
}
/*
@@ -2632,9 +2624,9 @@ static int img_convert(int argc, char **argv)
}
out_bs = blk_bs(s.target);
- if (nbitmaps > 0 && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
+ if (bitmaps && !bdrv_supports_persistent_dirty_bitmap(out_bs)) {
error_report("Format driver '%s' does not support bitmaps",
- out_fmt);
+ out_bs->drv->format_name);
ret = -1;
goto out;
}
@@ -2700,7 +2692,7 @@ static int img_convert(int argc, char **argv)
ret = convert_do_copy(&s);
/* Now copy the bitmaps */
- if (nbitmaps > 0 && ret == 0) {
+ if (bitmaps && ret == 0) {
ret = convert_copy_bitmaps(blk_bs(s.src[0]), out_bs);
}
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
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