On 6/28/23 8:58?AM, Jens Axboe wrote: > I should have something later today, don't feel like I fully understand > all of it just yet. Might indeed be delayed_fput, just the flush is a bit broken in that it races with the worker doing the flush. In any case, with testing that, I hit this before I got an umount failure on loop 6 of generic/388: External UUID: 724c7f1e-fed4-46e8-888a-2d5b170365b7 Internal UUID: 4c356134-e573-4aa4-a7b6-c22ab260e0ff Device index: 0 Label: Version: snapshot_trees Oldest version on disk: snapshot_trees Created: Wed Jun 28 09:16:47 2023 Sequence number: 0 Superblock size: 816 Clean: 0 Devices: 1 Sections: members Features: new_siphash,new_extent_overwrite,btree_ptr_v2,extents_above_btree_updates,btree_updates_journalled,new_varint,journal_no_flush,alloc_v2,extents_across_btree_nodes Compat features: Options: block_size: 512 B btree_node_size: 256 KiB errors: continue [ro] panic metadata_replicas: 1 data_replicas: 1 metadata_replicas_required: 1 data_replicas_required: 1 encoded_extent_max: 64.0 KiB metadata_checksum: none [crc32c] crc64 xxhash data_checksum: none [crc32c] crc64 xxhash compression: [none] lz4 gzip zstd background_compression: [none] lz4 gzip zstd str_hash: crc32c crc64 [siphash] metadata_target: none foreground_target: none background_target: none promote_target: none erasure_code: 0 inodes_32bit: 1 shard_inode_numbers: 1 inodes_use_key_cache: 1 gc_reserve_percent: 8 gc_reserve_bytes: 0 B root_reserve_percent: 0 wide_macs: 0 acl: 1 usrquota: 0 grpquota: 0 prjquota: 0 journal_flush_delay: 1000 journal_flush_disabled: 0 journal_reclaim_delay: 100 journal_transaction_names: 1 nocow: 0 members (size 64): Device: 0 UUID: dea79b51-ed22-4f11-9cb9-2117240419df Size: 20.0 GiB Bucket size: 256 KiB First bucket: 0 Buckets: 81920 Last mount: (never) State: rw Label: (none) Data allowed: journal,btree,user Has data: (none) Discard: 0 Freespace initialized: 0 initializing new filesystem going read-write initializing freespace mounted version=snapshot_trees seed = 1687442369 seed = 1687347478 seed = 1687934778 seed = 1687706987 seed = 1687173946 seed = 1687488122 seed = 1687828133 seed = 1687316163 seed = 1687511704 seed = 1687772088 seed = 1688057713 seed = 1687321139 seed = 1687166901 seed = 1687602318 seed = 1687659981 seed = 1687457702 seed = 1688000542 seed = 1687221947 seed = 1687740111 seed = 1688083754 seed = 1687314115 seed = 1687189436 seed = 1687664679 seed = 1687631074 seed = 1687691080 seed = 1688089920 seed = 1687962494 seed = 1687646206 seed = 1687636790 seed = 1687442248 seed = 1687532669 seed = 1687436103 seed = 1687626640 seed = 1687594091 seed = 1687235023 seed = 1687525509 seed = 1687766818 seed = 1688040782 seed = 1687293628 seed = 1687468804 seed = 1688129968 seed = 1687176698 seed = 1687603782 seed = 1687642709 seed = 1687844382 seed = 1687696290 seed = 1688169221 _check_generic_filesystem: filesystem on /dev/nvme0n1 is inconsistent *** fsck.bcachefs output *** fsck from util-linux 2.38.1 recovering from clean shutdown, journal seq 14642 journal read done, replaying entries 14642-14642 checking allocations starting journal replay, 0 keys checking need_discard and freespace btrees checking lrus checking backpointers to alloc keys checking backpointers to extents backpointer for missing extent u64s 9 type backpointer 0:7950303232:0 len 0 ver 0: bucket=0:15164:0 btree=extents l=0 offset=0:0 len=88 pos=1342182431:5745:U32_MAX, not fixing checking extents to backpointers checking alloc to lru refs starting fsck going read-write mounted version=snapshot_trees opts=degraded,fsck,fix_errors,nochanges 0xaaaafeb6b580g: still has errors *** end fsck.bcachefs output *** mount output *** /dev/vda2 on / type ext4 (rw,relatime,errors=remount-ro) devtmpfs on /dev type devtmpfs (rw,relatime,size=8174296k,nr_inodes=2043574,mode=755) proc on /proc type proc (rw,nosuid,nodev,noexec,relatime) sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime) securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime) tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev) devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000) tmpfs on /run type tmpfs (rw,nosuid,nodev,size=3276876k,nr_inodes=819200,mode=755) tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k) cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot) pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime) hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M) mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime) debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime) configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime) fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime) ramfs on /run/credentials/systemd-sysctl.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700) ramfs on /run/credentials/systemd-sysusers.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700) ramfs on /run/credentials/systemd-tmpfiles-setup-dev.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700) /dev/vda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) ramfs on /run/credentials/systemd-tmpfiles-setup.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700) *** end mount output -- Jens Axboe