On error path 'tree_root' is treed in 'free_fs_info()'.
No need to free it explicitely. Noticed by SLUB in debug mode:
Complete reproducer under usermode linux (discovered on real
machine):
bdev=/dev/ubda
btr_root=/btr
/mkfs.btrfs $bdev
mount $bdev $btr_root
mkdir $btr_root/subvols/
cd $btr_root/subvols/
/btrfs su cr foo
/btrfs su cr bar
mount $bdev -osubvol=subvols/foo $btr_root/subvols/bar
umount $btr_root/subvols/bar
which gives
device fsid 4d55aa28-45b1-474b-b4ec-da912322195e devid 1 transid 7 /dev/ubda
=============================================================================
BUG kmalloc-2048: Object already free
-----------------------------------------------------------------------------
INFO: Allocated in btrfs_mount+0x389/0x7f0 age=0 cpu=0 pid=277
INFO: Freed in btrfs_mount+0x51c/0x7f0 age=0 cpu=0 pid=277
INFO: Slab 0x0000000062886200 objects=15 used=9 fp=0x0000000070b4d2d0 flags=0x4081
INFO: Object 0x0000000070b4d2d0 @offset=21200 fp=0x0000000070b4a968
...
Call Trace:
70b31948: [<6008c522>] print_trailer+0xe2/0x130
70b31978: [<6008c5aa>] object_err+0x3a/0x50
70b319a8: [<6008e242>] free_debug_processing+0x142/0x2a0
70b319e0: [<600ebf6f>] btrfs_mount+0x55f/0x7f0
70b319f8: [<6008e5c1>] __slab_free+0x221/0x2d0
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Arne Jansen <sensille@gmx.net>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
45ea6095c8