[PATCH v3 0/2] block: deprecate the sheepdog driver

[PATCH v3 0/2] block: deprecate the sheepdog driver

[Daniel P. Berrangé]

2 years back I proposed dropping the sheepdog mailing list from the
MAINTAINERS file, but somehow the patch never got picked up:

  https://lists.gnu.org/archive/html/qemu-block/2018-03/msg01048.html

So here I am with the same patch again.

This time I go further and deprecate the sheepdog driver entirely.
See the rationale in the second patch commit message.

Changes in v3:

 - A few minor text changes
 - Don't initialize static variable to false

Daniel P. Berrangé (2):
  block: drop moderated sheepdog mailing list from MAINTAINERS file
  block: deprecate the sheepdog block driver

 MAINTAINERS                |  1 -
 block/sheepdog.c           | 14 ++++++++++++++
 configure                  |  5 +++--
 docs/system/deprecated.rst |  9 +++++++++
 4 files changed, 26 insertions(+), 3 deletions(-)

-- 
2.26.2

[PATCH v3 1/2] block: drop moderated sheepdog mailing list from MAINTAINERS file

[Daniel P. Berrangé]

The sheepdog mailing list is setup to stop and queue messages from
non-subscribers, pending moderator approval. Unfortunately it seems
that the moderation queue is not actively dealt with. Even when messages
are approved, the sender is never added to the whitelist, so every
future mail from the same sender continues to get stopped for moderation.

MAINTAINERS entries should be responsive and not unneccessarily block
mails from QEMU contributors, so drop the sheepdog mailing list.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 MAINTAINERS | 1 -
 1 file changed, 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index b76fb31861..c7d6601adf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2874,7 +2874,6 @@ F: block/rbd.c
 Sheepdog
 M: Liu Yuan <namei.unix@gmail.com>
 L: qemu-block@nongnu.org
-L: sheepdog@lists.wpkg.org
 S: Odd Fixes
 F: block/sheepdog.c
 
-- 
2.26.2

[PATCH v3 2/2] block: deprecate the sheepdog block driver

[Daniel P. Berrangé]

This thread from a little over a year ago:

  http://lists.wpkg.org/pipermail/sheepdog/2019-March/thread.html

states that sheepdog is no longer actively developed. The only mentioned
users are some companies who are said to have it for legacy reasons with
plans to replace it by Ceph. There is talk about cutting out existing
features to turn it into a simple demo of how to write a distributed
block service. There is no evidence of anyone working on that idea:

  https://github.com/sheepdog/sheepdog/commits/master

No real commits to git since Jan 2018, and before then just some minor
technical debt cleanup.

There is essentially no activity on the mailing list aside from
patches to QEMU that get CC'd due to our MAINTAINERS entry.

Fedora packages for sheepdog failed to build from upstream source
because of the more strict linker that no longer merges duplicate
global symbols. Fedora patches it to add the missing "extern"
annotations and presumably other distros do to, but upstream source
remains broken.

There is only basic compile testing, no functional testing of the
driver.

Since there are no build pre-requisites the sheepdog driver is currently
enabled unconditionally. This would result in configure issuing a
deprecation warning by default for all users. Thus the configure default
is changed to disable it, requiring users to pass --enable-sheepdog to
build the driver.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 block/sheepdog.c           | 14 ++++++++++++++
 configure                  |  5 +++--
 docs/system/deprecated.rst |  9 +++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/block/sheepdog.c b/block/sheepdog.c
index 2f5c0eb376..e270f2022c 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -242,6 +242,16 @@ typedef struct SheepdogInode {
  */
 #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
 
+static void deprecation_warning(void)
+{
+    static bool warned;
+
+    if (!warned) {
+        warn_report("the sheepdog block driver is deprecated");
+        warned = true;
+    }
+}
+
 /*
  * 64 bit Fowler/Noll/Vo FNV-1a hash code
  */
@@ -1548,6 +1558,8 @@ static int sd_open(BlockDriverState *bs, QDict *options, int flags,
     char *buf = NULL;
     QemuOpts *opts;
 
+    deprecation_warning();
+
     s->bs = bs;
     s->aio_context = bdrv_get_aio_context(bs);
 
@@ -2007,6 +2019,8 @@ static int sd_co_create(BlockdevCreateOptions *options, Error **errp)
 
     assert(options->driver == BLOCKDEV_DRIVER_SHEEPDOG);
 
+    deprecation_warning();
+
     s = g_new0(BDRVSheepdogState, 1);
 
     /* Steal SocketAddress from QAPI, set NULL to prevent double free */
diff --git a/configure b/configure
index ca9b458ea0..c5971fe560 100755
--- a/configure
+++ b/configure
@@ -533,7 +533,7 @@ vdi="yes"
 vvfat="yes"
 qed="yes"
 parallels="yes"
-sheepdog="yes"
+sheepdog="no"
 libxml2=""
 debug_mutex="no"
 libpmem=""
@@ -1940,7 +1940,7 @@ disabled with --disable-FEATURE, default is enabled if available:
   vvfat           vvfat image format support
   qed             qed image format support
   parallels       parallels image format support
-  sheepdog        sheepdog block driver support
+  sheepdog        sheepdog block driver support (deprecated)
   crypto-afalg    Linux AF_ALG crypto backend driver
   capstone        capstone disassembler support
   debug-mutex     mutex debugging support
@@ -7200,6 +7200,7 @@ if test "$parallels" = "yes" ; then
   echo "CONFIG_PARALLELS=y" >> $config_host_mak
 fi
 if test "$sheepdog" = "yes" ; then
+  add_to deprecated_features "sheepdog"
   echo "CONFIG_SHEEPDOG=y" >> $config_host_mak
 fi
 if test "$pty_h" = "yes" ; then
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index da862201ba..fbc67b189b 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -376,6 +376,15 @@ The above, converted to the current supported format::
 
   json:{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"}
 
+``sheepdog`` driver (since 5.2.0)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The ``sheepdog`` block device driver is deprecated. The corresponding upstream
+server project is no longer actively maintained. Users are recommended to switch
+to an alternative distributed block device driver such as RBD. The
+``qemu-img convert`` command can be used to liberate existing data by moving
+it out of sheepdog volumes into an alternative storage backend.
+
 linux-user mode CPUs
 --------------------
 
-- 
2.26.2

Re: [PATCH v3 0/2] block: deprecate the sheepdog driver

[Neal Gompa]

On Fri, Oct 2, 2020 at 7:34 AM Daniel P. Berrangé <berrange@redhat.com> wrote:
>
> 2 years back I proposed dropping the sheepdog mailing list from the
> MAINTAINERS file, but somehow the patch never got picked up:
>
>   https://lists.gnu.org/archive/html/qemu-block/2018-03/msg01048.html
>
> So here I am with the same patch again.
>
> This time I go further and deprecate the sheepdog driver entirely.
> See the rationale in the second patch commit message.
>
> Changes in v3:
>
>  - A few minor text changes
>  - Don't initialize static variable to false
>
> Daniel P. Berrangé (2):
>   block: drop moderated sheepdog mailing list from MAINTAINERS file
>   block: deprecate the sheepdog block driver
>
>  MAINTAINERS                |  1 -
>  block/sheepdog.c           | 14 ++++++++++++++
>  configure                  |  5 +++--
>  docs/system/deprecated.rst |  9 +++++++++
>  4 files changed, 26 insertions(+), 3 deletions(-)
>
> --
> 2.26.2
>

Series looks good to me.

Reviewed-by: Neal Gompa <ngompa13@gmail.com>


--
真実はいつも一つ！/ Always, there's only one truth!

Re: [PATCH v3 0/2] block: deprecate the sheepdog driver

[Kevin Wolf]

Am 02.10.2020 um 13:32 hat Daniel P. Berrangé geschrieben:
> 2 years back I proposed dropping the sheepdog mailing list from the
> MAINTAINERS file, but somehow the patch never got picked up:
> 
>   https://lists.gnu.org/archive/html/qemu-block/2018-03/msg01048.html
> 
> So here I am with the same patch again.
> 
> This time I go further and deprecate the sheepdog driver entirely.
> See the rationale in the second patch commit message.

Thanks, applied to the block branch.

Kevin