Re: [GIT PULL] bcachefs

[Jens Axboe <axboe@kernel.dk>]

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