diff mbox series

[v2,2/2] block: deprecate the sheepdog block driver

Message ID 20200922161611.2049616-3-berrange@redhat.com
State New
Headers show
Series block: deprecate the sheepdog driver | expand

Commit Message

Daniel P. Berrangé Sept. 22, 2020, 4:16 p.m. UTC
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.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 block/sheepdog.c           | 15 +++++++++++++++
 configure                  |  5 +++--
 docs/system/deprecated.rst |  9 +++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

Comments

Vladimir Sementsov-Ogievskiy Sept. 22, 2020, 5:53 p.m. UTC | #1
22.09.2020 19:16, Daniel P. Berrangé wrote:
> 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.
> 
> Signed-off-by: Daniel P. Berrangé<berrange@redhat.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Markus Armbruster Sept. 23, 2020, 1:50 p.m. UTC | #2
Daniel P. Berrangé <berrange@redhat.com> writes:

> 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..

Drop the extra period.

>
> 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.
>
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  block/sheepdog.c           | 15 +++++++++++++++
>  configure                  |  5 +++--
>  docs/system/deprecated.rst |  9 +++++++++
>  3 files changed, 27 insertions(+), 2 deletions(-)
>
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index cbbebc1aaf..7f68bd6a1a 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -242,6 +242,17 @@ typedef struct SheepdogInode {
>   */
>  #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
>  
> +static void deprecation_warning(void)
> +{
> +    static bool warned = false;

Obey checkpatch :)

> +
> +    if (!warned) {
> +        warn_report("the sheepdog block driver is deprecated and will be "
> +                    "removed in a future release");

Similar warnings elsewhere don't say "will be removed".

Some of them are nice enough to advise what to use instead, but that may
not be practical here.

> +        warned = true;
> +    }
> +}
> +
>  /*
>   * 64 bit Fowler/Noll/Vo FNV-1a hash code
>   */
> @@ -1548,6 +1559,8 @@ 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 +2020,8 @@ 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 7564479008..c6af83f2e6 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=""
> @@ -1941,7 +1941,7 @@ 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
> @@ -7350,6 +7350,7 @@ 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 0cb8b01424..49b9f4b02e 100644
> --- a/docs/system/deprecated.rst
> +++ b/docs/system/deprecated.rst
> @@ -405,6 +405,15 @@ 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
>  --------------------

Preferably with my nits addressed:
Reviewed-by: Markus Armbruster <armbru@redhat.com>
diff mbox series

Patch

diff --git a/block/sheepdog.c b/block/sheepdog.c
index cbbebc1aaf..7f68bd6a1a 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -242,6 +242,17 @@  typedef struct SheepdogInode {
  */
 #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
 
+static void deprecation_warning(void)
+{
+    static bool warned = false;
+
+    if (!warned) {
+        warn_report("the sheepdog block driver is deprecated and will be "
+                    "removed in a future release");
+        warned = true;
+    }
+}
+
 /*
  * 64 bit Fowler/Noll/Vo FNV-1a hash code
  */
@@ -1548,6 +1559,8 @@  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 +2020,8 @@  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 7564479008..c6af83f2e6 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=""
@@ -1941,7 +1941,7 @@  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
@@ -7350,6 +7350,7 @@  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 0cb8b01424..49b9f4b02e 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -405,6 +405,15 @@  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
 --------------------