This is a note to let you know that I've just added the patch titled
bcachefs: check for failure to downgrade
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bcachefs-check-for-failure-to-downgrade.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e50786c7bbb73fb754564802882c7b52511716ed Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Date: Fri, 22 Dec 2023 21:58:43 -0500
Subject: bcachefs: check for failure to downgrade
From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/bcachefs/errcode.h | 1 +
fs/bcachefs/super-io.c | 12 ++++++++++++
2 files changed, 13 insertions(+)
--- 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) \
--- 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;
Patches currently in stable-queue which might be from kent.overstreet@xxxxxxxxx are
queue-6.7/bcachefs-check-for-failure-to-downgrade.patch
queue-6.7/bcachefs-install-fd-later-to-avoid-race-with-close.patch
queue-6.7/bcachefs-fix-simulateously-upgrading-downgrading.patch
queue-6.7/bcachefs-fix-btree_iter_filter_snapshots-on-inodes-btree.patch
queue-6.7/bcachefs-fix-build-on-parisc-by-avoiding-__multi3.patch
