From: Kent Overstreet kent.overstreet@linux.dev
commit 447c1c01051251853e851bd77f26546488cbc7b7 upstream.
With the upcoming member seq patch, it's now critical that we don't ever write to a superblock that hasn't been version downgraded - failure to update member seq fields will cause split brain detection to fire erroniously.
Signed-off-by: Kent Overstreet kent.overstreet@linux.dev Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/bcachefs/errcode.h | 1 + fs/bcachefs/super-io.c | 12 ++++++++++++ 2 files changed, 13 insertions(+)
diff --git a/fs/bcachefs/errcode.h b/fs/bcachefs/errcode.h index 9ce29681eec96..ac90faccdcb22 100644 --- a/fs/bcachefs/errcode.h +++ b/fs/bcachefs/errcode.h @@ -224,6 +224,7 @@ x(BCH_ERR_invalid, invalid_bkey) \ x(BCH_ERR_operation_blocked, nocow_lock_blocked) \ x(EIO, btree_node_read_err) \ + x(EIO, sb_not_downgraded) \ x(BCH_ERR_btree_node_read_err, btree_node_read_err_fixable) \ x(BCH_ERR_btree_node_read_err, btree_node_read_err_want_retry) \ x(BCH_ERR_btree_node_read_err, btree_node_read_err_must_retry) \ diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c index 4c98d8cc2a797..6405cc1d651fd 100644 --- a/fs/bcachefs/super-io.c +++ b/fs/bcachefs/super-io.c @@ -966,6 +966,18 @@ int bch2_write_super(struct bch_fs *c) if (!BCH_SB_INITIALIZED(c->disk_sb.sb)) goto out;
+ if (le16_to_cpu(c->disk_sb.sb->version) > bcachefs_metadata_version_current) { + struct printbuf buf = PRINTBUF; + prt_printf(&buf, "attempting to write superblock that wasn't version downgraded ("); + bch2_version_to_text(&buf, le16_to_cpu(c->disk_sb.sb->version)); + prt_str(&buf, " > "); + bch2_version_to_text(&buf, bcachefs_metadata_version_current); + prt_str(&buf, ")"); + bch2_fs_fatal_error(c, "%s", buf.buf); + printbuf_exit(&buf); + return -BCH_ERR_sb_not_downgraded; + } + for_each_online_member(ca, c, i) { __set_bit(ca->dev_idx, sb_written.d); ca->sb_write_error = 0;