btrfs: Remove BTRFS_SUBVOL_CREATE_ASYNC support

This functionality was deprecated in kernel 5.4. Since no one has
complained of the impending removal it's time we did so.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ioctl.c

@@ -1818,8 +1818,6 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 {
 	struct btrfs_ioctl_vol_args_v2 *vol_args;
 	int ret;
-	u64 transid = 0;
-	u64 *ptr = NULL;
 	bool readonly = false;
 	struct btrfs_qgroup_inherit *inherit = NULL;
 
@@ -1836,15 +1834,6 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 		goto free_args;
 	}
 
-	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) {
-		struct inode *inode = file_inode(file);
-		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-
-		btrfs_warn(fs_info,
-"SNAP_CREATE_V2 ioctl with CREATE_ASYNC is deprecated and will be removed in kernel 5.7");
-
-		ptr = &transid;
-	}
 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
 		readonly = true;
 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
@@ -1860,17 +1849,10 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 	}
 
 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
-					      vol_args->fd, subvol, ptr,
+					      vol_args->fd, subvol, NULL,
 					      readonly, inherit);
 	if (ret)
 		goto free_inherit;
-
-	if (ptr && copy_to_user(arg +
-				offsetof(struct btrfs_ioctl_vol_args_v2,
-					transid),
-				ptr, sizeof(*ptr)))
-		ret = -EFAULT;
-
 free_inherit:
 	kfree(inherit);
 free_args:
@@ -1929,11 +1911,6 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
 		goto out_drop_write;
 	}
 
-	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
-		ret = -EINVAL;
-		goto out_drop_write;
-	}
-
 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
 		ret = -EOPNOTSUPP;
 		goto out_drop_write;

include/uapi/linux/btrfs.h

@@ -36,7 +36,12 @@ struct btrfs_ioctl_vol_args {
 #define BTRFS_DEVICE_PATH_NAME_MAX	1024
 #define BTRFS_SUBVOL_NAME_MAX 		4039
 
-#define BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
+/*
+ * Deprecated since 5.7:
+ *
+ * BTRFS_SUBVOL_CREATE_ASYNC	(1ULL << 0)
+ */
+
 #define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
 #define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)
 
@@ -45,8 +50,7 @@ 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)
@@ -116,8 +120,7 @@ struct btrfs_ioctl_qgroup_limit_args {
 
 /* Supported flags for BTRFS_IOC_SNAP_CREATE_V2 and BTRFS_IOC_SUBVOL_CREATE_V2 */
 #define BTRFS_SUBVOL_CREATE_ARGS_MASK					\
-	(BTRFS_SUBVOL_CREATE_ASYNC |					\
-	 BTRFS_SUBVOL_RDONLY |						\
+	 (BTRFS_SUBVOL_RDONLY |						\
 	 BTRFS_SUBVOL_QGROUP_INHERIT)
 
 /* Supported flags for BTRFS_IOC_SNAP_DESTROY_V2 */