diff mbox series

[v3] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

Message ID 20200402123147.18894-1-nborisov@suse.com (mailing list archive)
State New, archived
Headers show
Series [v3] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC | expand

Commit Message

Nikolay Borisov April 2, 2020, 12:31 p.m. UTC 
Kernel has removed support for this feature in 5.7 so let's remove
support from progs as well.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
---
Changelog V3:
 * Deleted unnecessary function documentation (Omar)
 * Decapitalize some words (Omar)

Changelog v2:
 * Removed async mentions in README.md
 * Changed docs in libbtrfsutil/btrfsutil.h to mention async is unused.
 * Removed tests using async_
 * Changed python module's doc to mention the async_ parameter is unused.
 ioctl.h                                     |  4 +--
 libbtrfsutil/README.md                      | 14 ++------
 libbtrfsutil/btrfs.h                        |  4 +--
 libbtrfsutil/btrfsutil.h                    | 23 +++++--------
 libbtrfsutil/python/module.c                |  6 ++--
 libbtrfsutil/python/tests/test_subvolume.py | 12 ++-----
 libbtrfsutil/subvolume.c                    | 38 ++++++---------------
 7 files changed, 29 insertions(+), 72 deletions(-)

--
2.17.1

Comments

David Sterba April 20, 2020, 10:56 p.m. UTC | #1 
On Thu, Apr 02, 2020 at 03:31:47PM +0300, Nikolay Borisov wrote:
> Kernel has removed support for this feature in 5.7 so let's remove
> support from progs as well.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> Reviewed-by: Omar Sandoval <osandov@fb.com>
> ---
> Changelog V3:
>  * Deleted unnecessary function documentation (Omar)
>  * Decapitalize some words (Omar)
> 
> Changelog v2:
>  * Removed async mentions in README.md
>  * Changed docs in libbtrfsutil/btrfsutil.h to mention async is unused.
>  * Removed tests using async_
>  * Changed python module's doc to mention the async_ parameter is unused.
>  ioctl.h                                     |  4 +--
>  libbtrfsutil/README.md                      | 14 ++------
>  libbtrfsutil/btrfs.h                        |  4 +--
>  libbtrfsutil/btrfsutil.h                    | 23 +++++--------
>  libbtrfsutil/python/module.c                |  6 ++--
>  libbtrfsutil/python/tests/test_subvolume.py | 12 ++-----
>  libbtrfsutil/subvolume.c                    | 38 ++++++---------------
>  7 files changed, 29 insertions(+), 72 deletions(-)
> 
> diff --git a/ioctl.h b/ioctl.h
> index ade6dcb91044..b63391f904c4 100644
> --- a/ioctl.h
> +++ b/ioctl.h
> @@ -49,15 +49,13 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);
> 
>  #define BTRFS_DEVICE_PATH_NAME_MAX 1024
> 
> -#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)

We got the report that removing the symbol breaks compilation, and ioctl.h is
exported to libbtrfs. I'm not aware of any 3rd party tool using this symbol, we
may want to make it more relaxed and keep the definition, but warn if is
used in any of the public interfaces.
Nikolay Borisov April 21, 2020, 9:36 a.m. UTC | #2 
On 21.04.20 г. 1:56 ч., David Sterba wrote:
> On Thu, Apr 02, 2020 at 03:31:47PM +0300, Nikolay Borisov wrote:
>> Kernel has removed support for this feature in 5.7 so let's remove
>> support from progs as well.
>>
>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>> Reviewed-by: Omar Sandoval <osandov@fb.com>
>> ---
>> Changelog V3:
>>  * Deleted unnecessary function documentation (Omar)
>>  * Decapitalize some words (Omar)
>>
>> Changelog v2:
>>  * Removed async mentions in README.md
>>  * Changed docs in libbtrfsutil/btrfsutil.h to mention async is unused.
>>  * Removed tests using async_
>>  * Changed python module's doc to mention the async_ parameter is unused.
>>  ioctl.h                                     |  4 +--
>>  libbtrfsutil/README.md                      | 14 ++------
>>  libbtrfsutil/btrfs.h                        |  4 +--
>>  libbtrfsutil/btrfsutil.h                    | 23 +++++--------
>>  libbtrfsutil/python/module.c                |  6 ++--
>>  libbtrfsutil/python/tests/test_subvolume.py | 12 ++-----
>>  libbtrfsutil/subvolume.c                    | 38 ++++++---------------
>>  7 files changed, 29 insertions(+), 72 deletions(-)
>>
>> diff --git a/ioctl.h b/ioctl.h
>> index ade6dcb91044..b63391f904c4 100644
>> --- a/ioctl.h
>> +++ b/ioctl.h
>> @@ -49,15 +49,13 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);
>>
>>  #define BTRFS_DEVICE_PATH_NAME_MAX 1024
>>
>> -#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
> 
> We got the report that removing the symbol breaks compilation, and ioctl.h is
> exported to libbtrfs. I'm not aware of any 3rd party tool using this symbol, we
> may want to make it more relaxed and keep the definition, but warn if is
> used in any of the public interfaces.

IMO that symbol should really be exposed from only one place - namely
the UAPI headers. So instead of having it defined here we ought to
include the respective UAPI header in libbtrfsutil. Also, I don't see an
include "ioctl.h" in any libbtrfsutil file:

git grep ioctl.h libbtrfsutil/
libbtrfsutil/btrfs.h:#include <linux/ioctl.h>
libbtrfsutil/filesystem.c:#include <sys/ioctl.h>
libbtrfsutil/subvolume.c:#include <sys/ioctl.h>


>
David Sterba April 27, 2020, 5:36 p.m. UTC | #3 
On Tue, Apr 21, 2020 at 12:36:21PM +0300, Nikolay Borisov wrote:
> 
> 
> On 21.04.20 г. 1:56 ч., David Sterba wrote:
> > On Thu, Apr 02, 2020 at 03:31:47PM +0300, Nikolay Borisov wrote:
> >> Kernel has removed support for this feature in 5.7 so let's remove
> >> support from progs as well.
> >>
> >> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> >> Reviewed-by: Omar Sandoval <osandov@fb.com>
> >> ---
> >> Changelog V3:
> >>  * Deleted unnecessary function documentation (Omar)
> >>  * Decapitalize some words (Omar)
> >>
> >> Changelog v2:
> >>  * Removed async mentions in README.md
> >>  * Changed docs in libbtrfsutil/btrfsutil.h to mention async is unused.
> >>  * Removed tests using async_
> >>  * Changed python module's doc to mention the async_ parameter is unused.
> >>  ioctl.h                                     |  4 +--
> >>  libbtrfsutil/README.md                      | 14 ++------
> >>  libbtrfsutil/btrfs.h                        |  4 +--
> >>  libbtrfsutil/btrfsutil.h                    | 23 +++++--------
> >>  libbtrfsutil/python/module.c                |  6 ++--
> >>  libbtrfsutil/python/tests/test_subvolume.py | 12 ++-----
> >>  libbtrfsutil/subvolume.c                    | 38 ++++++---------------
> >>  7 files changed, 29 insertions(+), 72 deletions(-)
> >>
> >> diff --git a/ioctl.h b/ioctl.h
> >> index ade6dcb91044..b63391f904c4 100644
> >> --- a/ioctl.h
> >> +++ b/ioctl.h
> >> @@ -49,15 +49,13 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);
> >>
> >>  #define BTRFS_DEVICE_PATH_NAME_MAX 1024
> >>
> >> -#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
> > 
> > We got the report that removing the symbol breaks compilation, and ioctl.h is
> > exported to libbtrfs. I'm not aware of any 3rd party tool using this symbol, we
> > may want to make it more relaxed and keep the definition, but warn if is
> > used in any of the public interfaces.
> 
> IMO that symbol should really be exposed from only one place - namely
> the UAPI headers.

It has been part of the libbtrfs public API for a long time so we need
to consider the backward compatibility, regardless what should have been
done differently.

> So instead of having it defined here we ought to
> include the respective UAPI header in libbtrfsutil.

No. The point of libbtrfsutil is to be independent and self contained,
and it has it's own copy of all btrfs structures that also happen to be
exported via UAPI.

> Also, I don't see an
> include "ioctl.h" in any libbtrfsutil file:
> 
> git grep ioctl.h libbtrfsutil/
> libbtrfsutil/btrfs.h:#include <linux/ioctl.h>
> libbtrfsutil/filesystem.c:#include <sys/ioctl.h>
> libbtrfsutil/subvolume.c:#include <sys/ioctl.h>

That's exactly right. Libbtrfsutil is library done the right way, unlike
libbtrfs, so the code is not shared.
Nikolay Borisov Aug. 27, 2020, 12:43 p.m. UTC | #4 
On 2.04.20 г. 15:31 ч., Nikolay Borisov wrote:
> Kernel has removed support for this feature in 5.7 so let's remove
> support from progs as well.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> Reviewed-by: Omar Sandoval <osandov@fb.com>
> ---
> Changelog V3:
>  * Deleted unnecessary function documentation (Omar)
>  * Decapitalize some words (Omar)
> 
> Changelog v2:
>  * Removed async mentions in README.md
>  * Changed docs in libbtrfsutil/btrfsutil.h to mention async is unused.
>  * Removed tests using async_
>  * Changed python module's doc to mention the async_ parameter is unused.
>  ioctl.h                                     |  4 +--
>  libbtrfsutil/README.md                      | 14 ++------
>  libbtrfsutil/btrfs.h                        |  4 +--
>  libbtrfsutil/btrfsutil.h                    | 23 +++++--------
>  libbtrfsutil/python/module.c                |  6 ++--
>  libbtrfsutil/python/tests/test_subvolume.py | 12 ++-----
>  libbtrfsutil/subvolume.c                    | 38 ++++++---------------
>  7 files changed, 29 insertions(+), 72 deletions(-)
> 

Ping.
diff mbox series

Patch

diff --git a/ioctl.h b/ioctl.h
index ade6dcb91044..b63391f904c4 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -49,15 +49,13 @@  BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);

 #define BTRFS_DEVICE_PATH_NAME_MAX 1024

-#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
 #define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
 #define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)
 #define BTRFS_DEVICE_SPEC_BY_ID		(1ULL << 3)
 #define BTRFS_SUBVOL_SPEC_BY_ID		(1ULL << 4)

 #define BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED		\
-			(BTRFS_SUBVOL_CREATE_ASYNC |	\
-			BTRFS_SUBVOL_RDONLY |		\
+			(BTRFS_SUBVOL_RDONLY |		\
 			BTRFS_SUBVOL_QGROUP_INHERIT |	\
 			BTRFS_DEVICE_SPEC_BY_ID |	\
 			BTRFS_SUBVOL_SPEC_BY_ID)
diff --git a/libbtrfsutil/README.md b/libbtrfsutil/README.md
index 8abb426d0adf..dcbae6399708 100644
--- a/libbtrfsutil/README.md
+++ b/libbtrfsutil/README.md
@@ -245,8 +245,7 @@  The equivalent `btrfs-progs` command is `btrfs subvolume list`.
 #### Creation

 `btrfs_util_create_subvolume()` creates a new subvolume at the given path. The
-subvolume can be created asynchronously and inherit from quota groups
-(qgroups).
+subvolume can inherit from quota groups (qgroups).

 Qgroups to inherit are specified with a `struct btrfs_util_qgroup_inherit`,
 which is created by `btrfs_util_create_qgroup_inherit()` and freed by
@@ -262,10 +261,6 @@  method and a `groups` member, which is a list of ints.
 ```c
 btrfs_util_create_subvolume("/subvol2", 0, NULL, NULL);

-uint64_t async_transid;
-btrfs_util_create_subvolume("/subvol2", 0, &async_transid, NULL);
-btrfs_util_wait_sync("/", async_transid);
-
 struct btrfs_util_qgroup_inherit *qgroups;
 btrfs_util_create_qgroup_inherit(0, &qgroups);
 btrfs_util_qgroup_inherit_add_group(&qgroups, 256);
@@ -276,9 +271,6 @@  btrfs_util_destroy_qgroup_inherit(qgroups);
 ```python
 btrfsutil.create_subvolume('/subvol2')

-async_transid = btrfsutil.create_subvolume('/subvol2', async_=True)
-btrfsutil.wait_sync('/', async_transid)
-
 qgroups = btrfsutil.QgroupInherit()
 qgroups.add_group(256)
 btrfsutil.create_subvolume('/subvol2', qgroup_inherit=qgroups)
@@ -292,8 +284,8 @@  The equivalent `btrfs-progs` command is `btrfs subvolume create`.
 #### Snapshotting

 Snapshots are created with `btrfs_util_create_snapshot()`, which takes a source
-path, a destination path, and flags. It can also be asynchronous and inherit
-from quota groups; see [subvolume creation](#Creation).
+path, a destination path, and flags. It can also inherit from quota groups;
+see [subvolume creation](#Creation).

 Snapshot creation can be recursive, in which case subvolumes underneath the
 subvolume being snapshotted will also be snapshotted onto the same location in
diff --git a/libbtrfsutil/btrfs.h b/libbtrfsutil/btrfs.h
index 60d51ff65171..4af2c21615f9 100644
--- a/libbtrfsutil/btrfs.h
+++ b/libbtrfsutil/btrfs.h
@@ -39,8 +39,7 @@  struct btrfs_ioctl_vol_args {
 #define BTRFS_SUBVOL_SPEC_BY_ID		(1ULL << 4)

 #define BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED		\
-			(BTRFS_SUBVOL_CREATE_ASYNC |	\
-			BTRFS_SUBVOL_RDONLY |		\
+			(BTRFS_SUBVOL_RDONLY |		\
 			BTRFS_SUBVOL_QGROUP_INHERIT |	\
 			BTRFS_DEVICE_SPEC_BY_ID |	\
 			BTRFS_SUBVOL_SPEC_BY_ID)
@@ -103,7 +102,6 @@  struct btrfs_ioctl_qgroup_limit_args {
  * - BTRFS_IOC_SUBVOL_GETFLAGS
  * - BTRFS_IOC_SUBVOL_SETFLAGS
  */
-#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
 #define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
 #define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)

diff --git a/libbtrfsutil/btrfsutil.h b/libbtrfsutil/btrfsutil.h
index 2c3b2f0e8f81..ff786a895926 100644
--- a/libbtrfsutil/btrfsutil.h
+++ b/libbtrfsutil/btrfsutil.h
@@ -366,16 +366,13 @@  struct btrfs_util_qgroup_inherit;
  * btrfs_util_create_subvolume() - Create a new subvolume.
  * @path: Where to create the subvolume.
  * @flags: Must be zero.
- * @async_transid: If not NULL, create the subvolume asynchronously (i.e.,
- * without waiting for it to commit it to disk) and return the transaction ID
- * that it was created in. This transaction ID can be waited on with
- * btrfs_util_wait_sync().
+ * @unused: No longer used
  * @qgroup_inherit: Qgroups to inherit from, or NULL.
  *
  * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
  */
 enum btrfs_util_error btrfs_util_create_subvolume(const char *path, int flags,
-						  uint64_t *async_transid,
+						  uint64_t *unused,
 						  struct btrfs_util_qgroup_inherit *qgroup_inherit);

 /**
@@ -385,7 +382,7 @@  enum btrfs_util_error btrfs_util_create_subvolume(const char *path, int flags,
  * should be created.
  * @name: Name of the subvolume to create.
  * @flags: See btrfs_util_create_subvolume().
- * @async_transid: See btrfs_util_create_subvolume().
+ * @unused: See btrfs_util_create_subvolume().
  * @qgroup_inherit: See btrfs_util_create_subvolume().
  *
  * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
@@ -393,7 +390,7 @@  enum btrfs_util_error btrfs_util_create_subvolume(const char *path, int flags,
 enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
 						     const char *name,
 						     int flags,
-						     uint64_t *async_transid,
+						     uint64_t *unused,
 						     struct btrfs_util_qgroup_inherit *qgroup_inherit);

 /**
@@ -418,16 +415,14 @@  enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
  * @source: Path of the existing subvolume to snapshot.
  * @path: Where to create the snapshot.
  * @flags: Bitmask of BTRFS_UTIL_CREATE_SNAPSHOT_* flags.
- * @async_transid: See btrfs_util_create_subvolume(). If
- * %BTRFS_UTIL_CREATE_SNAPSHOT_RECURSIVE was in @flags, then this will contain
- * the largest transaction ID of all created subvolumes.
+ * @unused: See btrfs_util_create_subvolume().
  * @qgroup_inherit: See btrfs_util_create_subvolume().
  *
  * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
  */
 enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
 						 const char *path, int flags,
-						 uint64_t *async_transid,
+						 uint64_t *unused,
 						 struct btrfs_util_qgroup_inherit *qgroup_inherit);

 /**
@@ -435,7 +430,7 @@  enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
  */
 enum btrfs_util_error btrfs_util_create_snapshot_fd(int fd, const char *path,
 						    int flags,
-						    uint64_t *async_transid,
+						    uint64_t *unused,
 						    struct btrfs_util_qgroup_inherit *qgroup_inherit);

 /**
@@ -446,13 +441,13 @@  enum btrfs_util_error btrfs_util_create_snapshot_fd(int fd, const char *path,
  * be created.
  * @name: Name of the snapshot to create.
  * @flags: See btrfs_util_create_snapshot().
- * @async_transid: See btrfs_util_create_snapshot().
+ * @unused: See btrfs_util_create_snapshot().
  * @qgroup_inherit: See btrfs_util_create_snapshot().
  */
 enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd, int parent_fd,
 						     const char *name,
 						     int flags,
-						     uint64_t *async_transid,
+						     uint64_t *unused,
 						     struct btrfs_util_qgroup_inherit *qgroup_inherit);

 /**
diff --git a/libbtrfsutil/python/module.c b/libbtrfsutil/python/module.c
index f8260c84ec76..157f1801dee6 100644
--- a/libbtrfsutil/python/module.c
+++ b/libbtrfsutil/python/module.c
@@ -237,8 +237,7 @@  static PyMethodDef btrfsutil_methods[] = {
 	 "Create a new subvolume.\n\n"
 	 "Arguments:\n"
 	 "path -- string, bytes, or path-like object\n"
-	 "async_ -- create the subvolume without waiting for it to commit to\n"
-	 "disk and return the transaction ID\n"
+	 "async_ -- no longer used\n"
 	 "qgroup_inherit -- optional QgroupInherit object of qgroups to\n"
 	 "inherit from"},
 	{"create_snapshot", (PyCFunction)create_snapshot,
@@ -251,8 +250,7 @@  static PyMethodDef btrfsutil_methods[] = {
 	 "path -- string, bytes, or path-like object\n"
 	 "recursive -- also snapshot child subvolumes\n"
 	 "read_only -- create a read-only snapshot\n"
-	 "async_ -- create the subvolume without waiting for it to commit to\n"
-	 "disk and return the transaction ID\n"
+	 "async_ -- no longer used\n"
 	 "qgroup_inherit -- optional QgroupInherit object of qgroups to\n"
 	 "inherit from"},
 	{"delete_subvolume", (PyCFunction)delete_subvolume,
diff --git a/libbtrfsutil/python/tests/test_subvolume.py b/libbtrfsutil/python/tests/test_subvolume.py
index 61055f53f484..0e0ecb20e0f4 100644
--- a/libbtrfsutil/python/tests/test_subvolume.py
+++ b/libbtrfsutil/python/tests/test_subvolume.py
@@ -244,10 +244,6 @@  from tests import (
         btrfsutil.create_subvolume(subvol + '6//')
         self.assertTrue(btrfsutil.is_subvolume(subvol + '6'))

-        transid = btrfsutil.create_subvolume(subvol + '7', async_=True)
-        self.assertTrue(btrfsutil.is_subvolume(subvol + '7'))
-        self.assertGreater(transid, 0)
-
         # Test creating subvolumes under '/' in a chroot.
         pid = os.fork()
         if pid == 0:
@@ -307,12 +303,8 @@  from tests import (
         btrfsutil.create_snapshot(subvol, snapshot + '2', recursive=True)
         self.assertTrue(os.path.exists(os.path.join(snapshot + '2', 'nested/more_nested/nested_dir')))

-        transid = btrfsutil.create_snapshot(subvol, snapshot + '3', recursive=True, async_=True)
-        self.assertTrue(os.path.exists(os.path.join(snapshot + '3', 'nested/more_nested/nested_dir')))
-        self.assertGreater(transid, 0)
-
-        btrfsutil.create_snapshot(subvol, snapshot + '4', read_only=True)
-        self.assertTrue(btrfsutil.get_subvolume_read_only(snapshot + '4'))
+        btrfsutil.create_snapshot(subvol, snapshot + '3', read_only=True)
+        self.assertTrue(btrfsutil.get_subvolume_read_only(snapshot + '3'))

     def test_delete_subvolume(self):
         subvol = os.path.join(self.mountpoint, 'subvol')
diff --git a/libbtrfsutil/subvolume.c b/libbtrfsutil/subvolume.c
index 204a837b0177..d20d32c8e903 100644
--- a/libbtrfsutil/subvolume.c
+++ b/libbtrfsutil/subvolume.c
@@ -683,7 +683,7 @@  static enum btrfs_util_error openat_parent_and_name(int dirfd, const char *path,

 PUBLIC enum btrfs_util_error btrfs_util_create_subvolume(const char *path,
 							 int flags,
-							 uint64_t *async_transid,
+							 uint64_t *unused,
 							 struct btrfs_util_qgroup_inherit *qgroup_inherit)
 {
 	char name[BTRFS_SUBVOL_NAME_MAX + 1];
@@ -696,7 +696,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_subvolume(const char *path,
 		return err;

 	err = btrfs_util_create_subvolume_fd(parent_fd, name, flags,
-					    async_transid, qgroup_inherit);
+					    unused, qgroup_inherit);
 	SAVE_ERRNO_AND_CLOSE(parent_fd);
 	return err;
 }
@@ -704,7 +704,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_subvolume(const char *path,
 PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
 							    const char *name,
 							    int flags,
-							    uint64_t *async_transid,
+							    uint64_t *unused,
 							    struct btrfs_util_qgroup_inherit *qgroup_inherit)
 {
 	struct btrfs_ioctl_vol_args_v2 args = {};
@@ -716,8 +716,6 @@  PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
 		return BTRFS_UTIL_ERROR_INVALID_ARGUMENT;
 	}

-	if (async_transid)
-		args.flags |= BTRFS_SUBVOL_CREATE_ASYNC;
 	if (qgroup_inherit) {
 		args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
 		args.qgroup_inherit = (struct btrfs_qgroup_inherit *)qgroup_inherit;
@@ -738,9 +736,6 @@  PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
 	if (ret == -1)
 		return BTRFS_UTIL_ERROR_SUBVOL_CREATE_FAILED;

-	if (async_transid)
-		*async_transid = args.transid;
-
 	return BTRFS_UTIL_OK;
 }

@@ -1022,8 +1017,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd,
 }

 static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd,
-							 const char *name,
-							 uint64_t *async_transid)
+							 const char *name)
 {
 	struct btrfs_util_subvolume_iterator *iter;
 	enum btrfs_util_error err;
@@ -1041,7 +1035,6 @@  static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd,
 		char child_name[BTRFS_SUBVOL_NAME_MAX + 1];
 		char *child_path;
 		int child_fd, new_parent_fd;
-		uint64_t tmp_transid;

 		err = btrfs_util_subvolume_iterator_next(iter, &child_path,
 							 NULL);
@@ -1076,14 +1069,11 @@  static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd,

 		err = btrfs_util_create_snapshot_fd2(child_fd, new_parent_fd,
 						     child_name, 0,
-						     async_transid ? &tmp_transid : NULL,
-						     NULL);
+						     NULL, NULL);
 		SAVE_ERRNO_AND_CLOSE(child_fd);
 		SAVE_ERRNO_AND_CLOSE(new_parent_fd);
 		if (err)
 			break;
-		if (async_transid && tmp_transid > *async_transid)
-			*async_transid = tmp_transid;
 	}

 	btrfs_util_destroy_subvolume_iterator(iter);
@@ -1095,7 +1085,7 @@  static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd,
 PUBLIC enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
 							const char *path,
 							int flags,
-							uint64_t *async_transid,
+							uint64_t *unused,
 							struct btrfs_util_qgroup_inherit *qgroup_inherit)
 {
 	enum btrfs_util_error err;
@@ -1105,7 +1095,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
 	if (fd == -1)
 		return BTRFS_UTIL_ERROR_OPEN_FAILED;

-	err = btrfs_util_create_snapshot_fd(fd, path, flags, async_transid,
+	err = btrfs_util_create_snapshot_fd(fd, path, flags, unused,
 					    qgroup_inherit);
 	SAVE_ERRNO_AND_CLOSE(fd);
 	return err;
@@ -1114,7 +1104,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
 PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd(int fd,
 							   const char *path,
 							   int flags,
-							   uint64_t *async_transid,
+							   uint64_t *unused,
 							   struct btrfs_util_qgroup_inherit *qgroup_inherit)
 {
 	char name[BTRFS_SUBVOL_NAME_MAX + 1];
@@ -1127,7 +1117,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd(int fd,
 		return err;

 	err = btrfs_util_create_snapshot_fd2(fd, parent_fd, name, flags,
-					     async_transid, qgroup_inherit);
+					     unused, qgroup_inherit);
 	SAVE_ERRNO_AND_CLOSE(parent_fd);
 	return err;
 }
@@ -1136,7 +1126,7 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd,
 							    int parent_fd,
 							    const char *name,
 							    int flags,
-							    uint64_t *async_transid,
+							    uint64_t *unused,
 							    struct btrfs_util_qgroup_inherit *qgroup_inherit)
 {
 	struct btrfs_ioctl_vol_args_v2 args = {.fd = fd};
@@ -1153,8 +1143,6 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd,

 	if (flags & BTRFS_UTIL_CREATE_SNAPSHOT_READ_ONLY)
 		args.flags |= BTRFS_SUBVOL_RDONLY;
-	if (async_transid)
-		args.flags |= BTRFS_SUBVOL_CREATE_ASYNC;
 	if (qgroup_inherit) {
 		args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
 		args.qgroup_inherit = (struct btrfs_qgroup_inherit *)qgroup_inherit;
@@ -1175,12 +1163,8 @@  PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd,
 	if (ret == -1)
 		return BTRFS_UTIL_ERROR_SUBVOL_CREATE_FAILED;

-	if (async_transid)
-		*async_transid = args.transid;
-
 	if (flags & BTRFS_UTIL_CREATE_SNAPSHOT_RECURSIVE) {
-		err = snapshot_subvolume_children(fd, parent_fd, name,
-						  async_transid);
+		err = snapshot_subvolume_children(fd, parent_fd, name);
 		if (err)
 			return err;
 	}