From: Eric Blake <eblake@redhat.com>
To: libguestfs@redhat.com
Cc: nsoffer@redhat.com, vsementsov@virtuozzo.com,
qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: [RFC libnbd PATCH] info: Add support for new qemu:joint-allocation
Date: Wed, 9 Jun 2021 16:31:54 -0500 [thread overview]
Message-ID: <20210609213154.1012848-1-eblake@redhat.com> (raw)
In-Reply-To: <20210609180118.1003774-1-eblake@redhat.com>
Qemu is adding qemu:joint-allocation as a single context combining the
two bits of base:allocation and a compression of qemu:allocation-depth
into two bits [1]. Decoding the bits makes it easier for humans to
see the result of that context.
[1] https://lists.gnu.org/archive/html/qemu-devel/2021-06/msg02446.html
---
Obviously, this libnbd patch should only go in if the qemu RFC is
accepted favorably. With this patch applied, the example listed in my
qemu patch 2/2 commit message [2] becomes
$ ~/libnbd/run nbdinfo --map=qemu:joint-allocation nbd://localhost
0 65536 3 hole,zero,unallocated
65536 65536 4 allocated,local
131072 65536 7 hole,zero,local
196608 65536 3 hole,zero,unallocated
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-06/msg02448.html
For what it's worth, you can also play with the qemu+libnbd patches at:
https://repo.or.cz/qemu/ericb.git/ master
https://repo.or.cz/libnbd/ericb.git/ master
(I sometimes rewind those branches, but they'll be stable for at least
a few days after this email)
info/map.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/info/map.c b/info/map.c
index ae6d4fe..21e8657 100644
--- a/info/map.c
+++ b/info/map.c
@@ -226,6 +226,27 @@ extent_description (const char *metacontext, uint32_t type)
return ret;
}
}
+ else if (strcmp (metacontext, "qemu:joint-allocation") == 0) {
+ /* Combo of base:allocation and stripped-down qemu:allocation-depth */
+ const char *base, *depth;
+ switch (type & 3) {
+ case 0: base = "allocated"; break;
+ case 1: base = "hole"; break;
+ case 2: base = "zero"; break;
+ case 3: base = "hole,zero"; break;
+ }
+ switch (type & 0xc) {
+ case 0: depth = "unallocated"; break;
+ case 4: depth = "local"; break;
+ case 8: depth = "backing"; break;
+ case 12: depth = "<unexpected depth>"; break;
+ }
+ if (asprintf (&ret, "%s,%s", base, depth) == -1) {
+ perror ("asprintf");
+ exit (EXIT_FAILURE);
+ }
+ return ret;
+ }
return NULL; /* Don't know - description field will be omitted. */
}
--
2.31.1
next prev parent reply other threads:[~2021-06-09 21:32 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 18:01 [RFC PATCH 0/2] New NBD metacontext Eric Blake
2021-06-09 18:01 ` [PATCH 1/2] iotests: Improve and rename test 309 to nbd-qemu-allocation Eric Blake
2021-06-10 12:14 ` Vladimir Sementsov-Ogievskiy
2021-06-09 18:01 ` [PATCH 2/2] nbd: Add new qemu:joint-allocation metadata context Eric Blake
2021-06-09 23:52 ` Nir Soffer
2021-06-10 12:30 ` Vladimir Sementsov-Ogievskiy
2021-06-10 13:47 ` Eric Blake
2021-06-10 14:10 ` Vladimir Sementsov-Ogievskiy
2021-06-10 13:16 ` Nir Soffer
2021-06-10 14:04 ` Eric Blake
2021-06-10 14:43 ` Vladimir Sementsov-Ogievskiy
2021-06-10 13:31 ` Eric Blake
2021-06-11 23:39 ` Nir Soffer
2021-06-14 13:56 ` Eric Blake
2021-06-14 14:06 ` Nir Soffer
2021-06-09 21:31 ` Eric Blake [this message]
2021-06-09 22:20 ` [RFC libnbd PATCH] info: Add support for new qemu:joint-allocation Nir Soffer
2021-06-10 13:06 ` Eric Blake
2021-06-10 13:19 ` Nir Soffer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210609213154.1012848-1-eblake@redhat.com \
--to=eblake@redhat.com \
--cc=libguestfs@redhat.com \
--cc=nsoffer@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=vsementsov@virtuozzo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).