We log warning if root::orphan_cleanup_state is not set to ORPHAN_CLEANUP_DONE in btrfs_ioctl_send(). However if the filesystem is mounted as readonly we skip the orphan items cleanup during the lookup and root::orphan_cleanup_state remains at the init state 0 instead of ORPHAN_CLEANUP_DONE (2). WARNING: CPU: 0 PID: 2616 at /Volumes/ws/btrfs-devel/fs/btrfs/send.c:7090 btrfs_ioctl_send+0xb2f/0x18c0 [btrfs] :: RIP: 0010:btrfs_ioctl_send+0xb2f/0x18c0 [btrfs] :: Call Trace: :: _btrfs_ioctl_send+0x7b/0x110 [btrfs] btrfs_ioctl+0x150a/0x2b00 [btrfs] :: do_vfs_ioctl+0xa9/0x620 ? __fget+0xac/0xe0 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x49/0x130 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reproducer: mkfs.btrfs -fq /dev/sdb && mount /dev/sdb /btrfs btrfs subvolume create /btrfs/sv1 btrfs subvolume snapshot -r /btrfs/sv1 /btrfs/ss1 umount /btrfs && mount -o ro /dev/sdb /btrfs btrfs send /btrfs/ss1 -f /tmp/f Fix this by checking for the expected ORPHAN_CLEANUP_DONE only if the filesystem is in writable state. Reported-by: Christoph Anton Mitterer <calestyo@xxxxxxxxxxxx> Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx> --- fs/btrfs/send.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index ae2db5eb1549..e3acec8aa8de 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -7085,9 +7085,11 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) /* * This is done when we lookup the root, it should already be complete - * by the time we get here. + * by the time we get here, unless the filesystem is readonly where the + * orphan_cleanup_state is never started. */ - WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE); + if (!sb_rdonly(file_inode(mnt_file)->i_sb)) + WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE); /* * Userspace tools do the checks and warn the user if it's -- 2.23.0
