btrfs: WARN_ON(data_sinfo->bytes_may_use < bytes);

Just hit this while running trinity.

WARNING: CPU: 3 PID: 9612 at fs/btrfs/extent-tree.c:3799 btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]()
Modules linked in: rfcomm hidp bnep af_key llc2 scsi_transport_iscsi nfnetlink sctp libcrc32c can_raw can_bcm nfc caif_socket caif af_802154 ieee802154 phonet af_rxrpc bluetooth can pppoe pppox ppp_generic slhc irda crc_ccitt rds rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 cfg80211 rfkill btrfs xor coretemp hwmon x86_pkg_temp_thermal kvm_intel snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic kvm crct10dif_pclmul crc32c_intel ghash_clmulni_intel raid6_pq snd_hda_intel microcode snd_hda_controller pcspkr snd_hda_codec serio_raw snd_hwdep snd_seq snd_seq_device usb_debug snd_pcm e1000e ptp shpchp pps_core snd_timer snd soundcore
CPU: 3 PID: 9612 Comm: trinity-c85 Not tainted 3.18.0-rc1+ #74
 0000000000000009 000000009989d5b8 ffff88018a337ba8 ffffffffaf86cc97
 0000000000000000 0000000000000000 ffff88018a337be8 ffffffffaf07f301
 ffff88022ddf8d40 ffff88023f799148 000000007fbbf000 ffff88009c2b59c8
Call Trace:
 [<ffffffffaf86cc97>] dump_stack+0x4f/0x7c
 [<ffffffffaf07f301>] warn_slowpath_common+0x81/0xa0
 [<ffffffffaf07f41a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffc045b831>] btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]
 [<ffffffffc045d0b2>] btrfs_delalloc_release_space+0x22/0x30 [btrfs]
 [<ffffffffc047994b>] btrfs_direct_IO+0x33b/0x350 [btrfs]
 [<ffffffffc0487400>] ? btrfs_page_exists_in_range+0x2c0/0x2c0 [btrfs]

 [<ffffffffc047b2b0>] ? btrfs_real_readdir+0x5e0/0x5e0 [btrfs]
 [<ffffffffaf1adbb4>] generic_file_direct_write+0xc4/0x1a0
 [<ffffffffc048b246>] btrfs_file_write_iter+0x186/0x560 [btrfs]
 [<ffffffffaf22abde>] new_sync_write+0x8e/0xd0
 [<ffffffffaf22b5ca>] vfs_write+0xba/0x1f0
 [<ffffffffaf24fbce>] ? __fget_light+0xbe/0xe0
 [<ffffffffaf22c2d2>] SyS_pwrite64+0x92/0xc0
 [<ffffffffaf877d49>] tracesys_phase2+0xd4/0xd9

Quoted 16 lines · Dave Jones

Just hit this while running trinity.

WARNING: CPU: 3 PID: 9612 at fs/btrfs/extent-tree.c:3799 btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]()
Modules linked in: rfcomm hidp bnep af_key llc2 scsi_transport_iscsi nfnetlink sctp libcrc32c can_raw can_bcm nfc caif_socket caif af_802154 ieee802154 phonet af_rxrpc bluetooth can pppoe pppox ppp_generic slhc irda crc_ccitt rds rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 cfg80211 rfkill btrfs xor coretemp hwmon x86_pkg_temp_thermal kvm_intel snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic kvm crct10dif_pclmul crc32c_intel ghash_clmulni_intel raid6_pq snd_hda_intel microcode snd_hda_controller pcspkr snd_hda_codec serio_raw snd_hwdep snd_seq snd_seq_device usb_debug snd_pcm e1000e ptp shpchp pps_core snd_timer snd soundcore
CPU: 3 PID: 9612 Comm: trinity-c85 Not tainted 3.18.0-rc1+ #74
 0000000000000009 000000009989d5b8 ffff88018a337ba8 ffffffffaf86cc97
 0000000000000000 0000000000000000 ffff88018a337be8 ffffffffaf07f301
 ffff88022ddf8d40 ffff88023f799148 000000007fbbf000 ffff88009c2b59c8
Call Trace:
 [<ffffffffaf86cc97>] dump_stack+0x4f/0x7c
 [<ffffffffaf07f301>] warn_slowpath_common+0x81/0xa0
 [<ffffffffaf07f41a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffc045b831>] btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]
 [<ffffffffc045d0b2>] btrfs_delalloc_release_space+0x22/0x30 [btrfs]
 [<ffffffffc047994b>] btrfs_direct_IO+0x33b/0x350 [btrfs]
 [<ffffffffc0487400>] ? btrfs_page_exists_in_range+0x2c0/0x2c0 [btrfs]

Quoted 8 lines

 [<ffffffffc047b2b0>] ? btrfs_real_readdir+0x5e0/0x5e0 [btrfs]
 [<ffffffffaf1adbb4>] generic_file_direct_write+0xc4/0x1a0
 [<ffffffffc048b246>] btrfs_file_write_iter+0x186/0x560 [btrfs]
 [<ffffffffaf22abde>] new_sync_write+0x8e/0xd0
 [<ffffffffaf22b5ca>] vfs_write+0xba/0x1f0
 [<ffffffffaf24fbce>] ? __fget_light+0xbe/0xe0
 [<ffffffffaf22c2d2>] SyS_pwrite64+0x92/0xc0
 [<ffffffffaf877d49>] tracesys_phase2+0xd4/0xd9

I also see this WARN_ON being hit from the sync path..

WARNING: CPU: 2 PID: 11166 at fs/btrfs/extent-tree.c:3799 btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]()
CPU: 2 PID: 11166 Comm: trinity-c61 Tainted: G        W      3.18.0-rc1+ #74
 0000000000000009 00000000aee2e4e2 ffff8801b0dfbcc8 ffffffff8d86cc97
 0000000000000000 0000000000000000 ffff8801b0dfbd08 ffffffff8d07f301
 ffff88023f328000 ffff88023953d668 0000000000040000 ffff880239358548
Call Trace:
 [<ffffffff8d86cc97>] dump_stack+0x4f/0x7c
 [<ffffffff8d07f301>] warn_slowpath_common+0x81/0xa0
 [<ffffffff8d07f41a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffc0253831>] btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]
 [<ffffffffc025ca63>] btrfs_write_dirty_block_groups+0x6f3/0x740 [btrfs]
 [<ffffffffc02f7a41>] commit_cowonly_roots+0x17a/0x234 [btrfs]
 [<ffffffffc026e60b>] btrfs_commit_transaction+0x45b/0xc10 [btrfs]
 [<ffffffffc023a09b>] btrfs_sync_fs+0x8b/0x270 [btrfs]
 [<ffffffff8d266ad0>] ? do_fsync+0x80/0x80
 [<ffffffff8d266af0>] sync_fs_one_sb+0x20/0x30
 [<ffffffff8d22f2f2>] iterate_supers+0xb2/0x110
 [<ffffffff8d266c24>] sys_sync+0x64/0xb0
 [<ffffffff8d877d49>] tracesys_phase2+0xd4/0xd9

After rebooting, and restarting the fuzzer, it happened again very quickly.

Quoted 22 lines

I also see this WARN_ON being hit from the sync path..

WARNING: CPU: 2 PID: 11166 at fs/btrfs/extent-tree.c:3799 btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]()
CPU: 2 PID: 11166 Comm: trinity-c61 Tainted: G        W      3.18.0-rc1+ #74
 0000000000000009 00000000aee2e4e2 ffff8801b0dfbcc8 ffffffff8d86cc97
 0000000000000000 0000000000000000 ffff8801b0dfbd08 ffffffff8d07f301
 ffff88023f328000 ffff88023953d668 0000000000040000 ffff880239358548
Call Trace:
 [<ffffffff8d86cc97>] dump_stack+0x4f/0x7c
 [<ffffffff8d07f301>] warn_slowpath_common+0x81/0xa0
 [<ffffffff8d07f41a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffc0253831>] btrfs_free_reserved_data_space+0x1d1/0x280 [btrfs]
 [<ffffffffc025ca63>] btrfs_write_dirty_block_groups+0x6f3/0x740 [btrfs]
 [<ffffffffc02f7a41>] commit_cowonly_roots+0x17a/0x234 [btrfs]
 [<ffffffffc026e60b>] btrfs_commit_transaction+0x45b/0xc10 [btrfs]
 [<ffffffffc023a09b>] btrfs_sync_fs+0x8b/0x270 [btrfs]
 [<ffffffff8d266ad0>] ? do_fsync+0x80/0x80
 [<ffffffff8d266af0>] sync_fs_one_sb+0x20/0x30
 [<ffffffff8d22f2f2>] iterate_supers+0xb2/0x110
 [<ffffffff8d266c24>] sys_sync+0x64/0xb0
 [<ffffffff8d877d49>] tracesys_phase2+0xd4/0xd9

Quoted 1 line

After rebooting, and restarting the fuzzer, it happened again very quickly.

Could you please show us the trinity options you're using?

I also see this WARNing from other reports, but still try to reproduce..