[PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[Nikolay Borisov]

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>
---
 ioctl.h                  | 4 +---
 libbtrfsutil/btrfs.h     | 4 +---
 libbtrfsutil/subvolume.c | 4 ----
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/ioctl.h b/ioctl.h
index d3dfd6375de1..93a19a5789b6 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -49,14 +49,12 @@ 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_VOL_ARG_V2_FLAGS_SUPPORTED		\
-			(BTRFS_SUBVOL_CREATE_ASYNC |	\
-			BTRFS_SUBVOL_RDONLY |		\
+			(BTRFS_SUBVOL_RDONLY |		\
 			BTRFS_SUBVOL_QGROUP_INHERIT |	\
 			BTRFS_DEVICE_SPEC_BY_ID)
 
diff --git a/libbtrfsutil/btrfs.h b/libbtrfsutil/btrfs.h
index 944d50132456..03ac58372104 100644
--- a/libbtrfsutil/btrfs.h
+++ b/libbtrfsutil/btrfs.h
@@ -38,8 +38,7 @@ struct btrfs_ioctl_vol_args {
 #define BTRFS_DEVICE_SPEC_BY_ID		(1ULL << 3)
 
 #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)
 
@@ -101,7 +100,6 @@ 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/subvolume.c b/libbtrfsutil/subvolume.c
index 3f8343a245e9..27a6bb8130ed 100644
--- a/libbtrfsutil/subvolume.c
+++ b/libbtrfsutil/subvolume.c
@@ -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;
@@ -1153,8 +1151,6 @@ 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;
-- 
2.17.1

Re: [PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[Omar Sandoval]

On Fri, Mar 13, 2020 at 05:31:43PM +0200, 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>
> ---
>  ioctl.h                  | 4 +---
>  libbtrfsutil/btrfs.h     | 4 +---
>  libbtrfsutil/subvolume.c | 4 ----
>  3 files changed, 2 insertions(+), 10 deletions(-)

We should also update the docs in libbtrfsutil/btrfsutil.h and
libbtrfsutil/python/module.c to note that async_transid/async_ is now
ignored, remove the mentions of asynchronous creation from
libbtrfsutil/README.md, and remove the async_ tests in
libbtrfsutil/python/tests/test_subvolume.py.

> diff --git a/ioctl.h b/ioctl.h
> index d3dfd6375de1..93a19a5789b6 100644
> --- a/ioctl.h
> +++ b/ioctl.h
> @@ -49,14 +49,12 @@ 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_VOL_ARG_V2_FLAGS_SUPPORTED		\
> -			(BTRFS_SUBVOL_CREATE_ASYNC |	\
> -			BTRFS_SUBVOL_RDONLY |		\
> +			(BTRFS_SUBVOL_RDONLY |		\
>  			BTRFS_SUBVOL_QGROUP_INHERIT |	\
>  			BTRFS_DEVICE_SPEC_BY_ID)
>  
> diff --git a/libbtrfsutil/btrfs.h b/libbtrfsutil/btrfs.h
> index 944d50132456..03ac58372104 100644
> --- a/libbtrfsutil/btrfs.h
> +++ b/libbtrfsutil/btrfs.h
> @@ -38,8 +38,7 @@ struct btrfs_ioctl_vol_args {
>  #define BTRFS_DEVICE_SPEC_BY_ID		(1ULL << 3)
>  
>  #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)
>  
> @@ -101,7 +100,6 @@ 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/subvolume.c b/libbtrfsutil/subvolume.c
> index 3f8343a245e9..27a6bb8130ed 100644
> --- a/libbtrfsutil/subvolume.c
> +++ b/libbtrfsutil/subvolume.c
> @@ -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;
> @@ -1153,8 +1151,6 @@ 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;

Please remove all of the handling for async_transid from this file.

[PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[Nikolay Borisov]

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>
---

This has been languishing on my local branch, let's merge it and be done with
it once for all.

 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 5ce47c838b0e..aad3e9772908 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 d9194f5fd842..d20f33980500 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 a31173623249..3388381f36a3 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 ddd2a7b2ae73..fedd9832113f 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 729f76db23f1..2657ee289f6f 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 2620b5c5cfde..690ff107680d 100644
--- a/libbtrfsutil/python/tests/test_subvolume.py
+++ b/libbtrfsutil/python/tests/test_subvolume.py
@@ -245,10 +245,6 @@ 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:
@@ -308,12 +304,8 @@ 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 32086b7fcc7a..deff6de7c84e 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;
 	}
--
2.25.1

Re: [PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[David Sterba]

On Thu, Sep 23, 2021 at 03:41:27PM +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>
> ---
> 
> This has been languishing on my local branch, let's merge it and be done with
> it once for all.
> 
>  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 5ce47c838b0e..aad3e9772908 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 had the problem in kernel, fixed by 34c51814b2b87cb2e, we can't just
remove things from public interfaces.

Re: [PATCH] btrfs-progs: Remove support for BTRFS_SUBVOL_CREATE_ASYNC

[David Sterba]

On Thu, Sep 23, 2021 at 03:41:27PM +0300, Nikolay Borisov wrote:
> Kernel has removed support for this feature in 5.7 so let's remove
> support from progs as well.

For the record, summary of the discussion.  Removing this is from progs
an libbtrfsutil does not seem to be that critical like the kernel patch,
as eg. strace uses the kernel uapi definition and also does conditional
tests if the macro even exists.

If something is using libbtrfs-devel/ioctl.h, then it should switch to
the kernel uapi but I haven't found any such project.

We may still need to keep some placeholder or comment that the value
used to mean something. We could potentially reuse it in the future, but
there must be some deprecation period.