On Sat, Oct 26, 2024 at 12:15:49AM +0000, Piotr Zalewski wrote: > Initialize freespace_initialized bits to 0 in member's flags and update > member's cached version for each device in bch2_fs_initialize. > > It's possible for the bits to be set to 1 before fs is initialized and if > call to bch2_trans_mark_dev_sbs (just before bch2_fs_freespace_init) fails > bits remain to be 1 which can later indirectly trigger BUG condition in > bch2_bucket_alloc_freelist during shutdown. > > Reported-by: syzbot+2b6a17991a6af64f9...@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=2b6a17991a6af64f9489 > Fixes: bbe682c76789 ("bcachefs: Ensure devices are always correctly > initialized") > Suggested-by: Kent Overstreet <kent.overstr...@linux.dev> > Signed-off-by: Piotr Zalewski <pz010001011...@proton.me> > --- > > Notes: > changes in v3: > - v2 rebased > > changes in v2: > - unconditionally set freespace initialized bits to false at > the top of bch2_fs_initialized instead of only if > bch2_trans_mark_dev_sbs fails > > Link to v2: > https://lore.kernel.org/linux-bcachefs/20241021174151.37692-2-pz010001011...@proton.me/ > Link to v1: > https://lore.kernel.org/linux-bcachefs/20241020170708.67044-2-pz010001011...@proton.me/ > > fs/bcachefs/recovery.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c > index fdf2aa2ffc13..8d4c93a1f5aa 100644 > --- a/fs/bcachefs/recovery.c > +++ b/fs/bcachefs/recovery.c > @@ -1029,6 +1029,7 @@ int bch2_fs_initialize(struct bch_fs *c) > struct bch_inode_unpacked root_inode, lostfound_inode; > struct bkey_inode_buf packed_inode; > struct qstr lostfound = QSTR("lost+found"); > + struct bch_member *m; > int ret; > > bch_notice(c, "initializing new filesystem"); > @@ -1045,6 +1046,13 @@ int bch2_fs_initialize(struct bch_fs *c) > SET_BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb, > bcachefs_metadata_version_current); > bch2_write_super(c); > } > + > + for_each_member_device(c, ca) { > + m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx); > + SET_BCH_MEMBER_FREESPACE_INITIALIZED(m, false); > + ca->mi = bch2_mi_to_cpu(m); > + } > +
I'm also adding a write_super() call here: that's what updates ca->mi.freespace_initialized which the freespace init path will later check. > mutex_unlock(&c->sb_lock); > > c->curr_recovery_pass = BCH_RECOVERY_PASS_NR; > -- > 2.47.0 > >
