Bug 216086

Summary:	btrfs-progs using btrfs-convert aborts with an assert
Product:	File System	Reporter:	torbjorn
Component:	btrfs	Assignee:	BTRFS virtual assignee (fs_btrfs)
Status:	NEW ---
Severity:	normal
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	5.15.35	Subsystem:
Regression:	No	Bisected commit-id:

Description torbjorn 2022-06-06 15:26:03 UTC

Hello.

I tried to run btrfs-convert on one of my ext4 filesystems and all i got was this:

--
btrfs-convert from btrfs-progs v5.16.2

convert/main.c:1162: do_convert: Assertion `cctx.total_bytes != 0` failed, value 0
btrfs-convert(+0xffb0)[0x557defdabfb0]
btrfs-convert(main+0x6c5)[0x557defdaa125]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xea)[0x7f66e1f8bd0a]
btrfs-convert(_start+0x2a)[0x557defdab52a]
Aborted
--

The filesystem is 16TiB using ext4 and it got around 8TiB of data used on it.
The ext4 filesystem contains almost exclusively large files, some of over 1TiB.