bcachefs: Put erasure coding behind an EXPERIMENTAL kconfig option

We still have disk space accounting changes coming for erasure coding,
and the changes won't be as strictly backwards compatible as they'd
ought to be - specifically, we need to start accounting striped data
under a separate counter in bch_alloc (which describes buckets).

A fsck will suffice for upgrading/downgrading, but since erasure coding
is the most incomplete major feature of bcachefs it still makes sense to
put behind a separate kconfig option, so that users are fully aware.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/Kconfig b/fs/bcachefs/Kconfig
index c08c2c7d6fbbab79e34b0321b7bdc300fd575dfb..fddc7be580223a54357deb7647b9fa41748679e3 100644 (file)
--- a/fs/bcachefs/Kconfig
+++ b/fs/bcachefs/Kconfig
@@ -33,6 +33,18 @@ config BCACHEFS_QUOTA
        depends on BCACHEFS_FS
        select QUOTACTL
 
+config BCACHEFS_ERASURE_CODING
+       bool "bcachefs erasure coding (RAID5/6) support (EXPERIMENTAL)"
+       depends on BCACHEFS_FS
+       select QUOTACTL
+       help
+       This enables the "erasure_code" filesysystem and inode option, which
+       organizes data into reed-solomon stripes instead of ordinary
+       replication.
+
+       WARNING: this feature is still undergoing on disk format changes, and
+       should only be enabled for testing purposes.
+
 config BCACHEFS_POSIX_ACL
        bool "bcachefs POSIX ACL support"
        depends on BCACHEFS_FS

diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index b85c7765272f6e4ae5e8aceb5a4bbaa89c535912..5042858719c087969d9eacc55dc337a8123a269b 100644 (file)
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -1321,6 +1321,9 @@ int bch2_alloc_sectors_start_trans(struct btree_trans *trans,
        int ret;
        int i;
 
+       if (!IS_ENABLED(CONFIG_BCACHEFS_ERASURE_CODING))
+               erasure_code = false;
+
        BUG_ON(flags & BCH_WRITE_ONLY_SPECIFIED_DEVS);
 
        BUG_ON(!nr_replicas || !nr_replicas_required);