From 31df2f2b750dd714e29cdff9fe48d0c0e4e9cbd8 Mon Sep 17 00:00:00 2001
From: Mike Fleetwood <mike.fleetwood@googlemail.com>
Date: Sun, 17 Mar 2024 08:03:50 +0000
Subject: [PATCH] Add bcachefs growing (!123)

Shrinking a bcachefs file system is not supported.
    # truncate -s $((1*1024*1024*1024)) /tmp/disk.img
    # losetup --find --show /tmp/disk.img
    /dev/loop0
    # bcachefs format /dev/loop0
    ...
    # bcachefs device resize /dev/loop0 $((1*1024*1024*1024 - 512))
    Doing offline resize of /dev/loop0
    mounting version 1.4: member_seq
    initializing new filesystem
    going read-write
    initializing freespace
    Shrinking not supported yet
    # echo $?
    1

Growing a bcachefs file system is supported when unmounted.
    # truncate -s $((2*1024*1024*1024)) /tmp/disk.img
    # losetup --set-capacity /dev/loop0
    # bcachefs device resize /dev/loop0
    Doing offline resize of /dev/loop0
    mounting version 1.6: btree_subvolume_children
    recovering from unclean shutdown
    journal read done, replaying entries 1-1
    alloc_read... done
    stripes_read... done
    snapshots_read... done
    going read-write
    journal_replay... done
    resume_logged_ops... done
    delete_dead_inodes... done
    resizing /dev/loop0 to 16384 buckets
    # echo $?
    0
    # bcachefs show-super /dev/loop0 | egrep 'Device:|Size:'
    Device:                                     0
      Size:                                     2.00 GiB

Growing is also supported when mounted.
    # mount /dev/loop0 /mnt/0
    # truncate -s $((3*1024*1024*1024)) /tmp/disk.img
    # losetup --set-capacity /dev/loop0
    # bcachefs device resize /dev/loop0
    Doing online resize of /dev/loop0
    resizing /dev/loop0 to 24576 buckets
    # echo $?
    0
    # bcachefs show-super /dev/loop0 | egrep 'Device:|Size:'
    Device:                                     0
      Size:                                     3.00 GiB

Closes !123 - Add support for bcachefs, single device file systems only
---
 include/bcachefs.h |  1 +
 src/bcachefs.cc    | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/include/bcachefs.h b/include/bcachefs.h
index 94a4d80f..b04744b9 100644
--- a/include/bcachefs.h
+++ b/include/bcachefs.h
@@ -36,6 +36,7 @@ public:
 	bool create(const Partition& new_partition, OperationDetail& operationdetail);
 	void read_label(Partition& partition);
 	void read_uuid(Partition& partition);
+	bool resize(const Partition& partition_new, OperationDetail& operationdetail, bool fill_partition);
 };
 
 
diff --git a/src/bcachefs.cc b/src/bcachefs.cc
index f8c1f082..1a6514ae 100644
--- a/src/bcachefs.cc
+++ b/src/bcachefs.cc
@@ -45,6 +45,11 @@ FS bcachefs::get_filesystem_support()
 		fs.create_with_label = FS::EXTERNAL;
 		fs.read_label        = FS::EXTERNAL;
 		fs.read_uuid         = FS::EXTERNAL;
+		fs.grow              = FS::EXTERNAL;
+#ifdef ENABLE_ONLINE_RESIZE
+		if (Utils::kernel_version_at_least(3, 6, 0))
+			fs.online_grow = FS::EXTERNAL;
+#endif
 	}
 
 	fs_limits.min_size = 32 * MEBIBYTE;
@@ -131,4 +136,11 @@ void bcachefs::read_uuid(Partition& partition)
 }
 
 
+bool bcachefs::resize(const Partition& partition_new, OperationDetail& operationdetail, bool fill_partition)
+{
+	return ! execute_command("bcachefs device resize " + Glib::shell_quote(partition_new.get_path()),
+	                         operationdetail, EXEC_CHECK_STATUS);
+}
+
+
 } //GParted