Commit 4a4f9b5c authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Don't set BCH_FEATURE_incompat_version_field unless requested 



We shouldn't be setting incompatible bits or the incompatible version
field unless explicitly request or allowed - otherwise we break mounting
with old kernels or userspace.

Reported-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent eb54d269

fs/bcachefs/super-io.c

+16 −8
Original line number Diff line number Diff line
@@ -69,16 +69,22 @@ enum bcachefs_metadata_version bch2_latest_compatible_version(enum bcachefs_meta 
	return v;

}



void bch2_set_version_incompat(struct bch_fs *c, enum bcachefs_metadata_version version)

bool bch2_set_version_incompat(struct bch_fs *c, enum bcachefs_metadata_version version)

{

	bool ret = (c->sb.features & BIT_ULL(BCH_FEATURE_incompat_version_field)) &&

		   version <= c->sb.version_incompat_allowed;



	if (ret) {

		mutex_lock(&c->sb_lock);

		SET_BCH_SB_VERSION_INCOMPAT(c->disk_sb.sb,

			max(BCH_SB_VERSION_INCOMPAT(c->disk_sb.sb), version));

	c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_FEATURE_incompat_version_field);

		bch2_write_super(c);

		mutex_unlock(&c->sb_lock);

	}



	return ret;

}



const char * const bch2_sb_fields[] = {

#define x(name, nr)	#name,

	BCH_SB_FIELDS()
@@ -1219,9 +1225,11 @@ void bch2_sb_upgrade(struct bch_fs *c, unsigned new_version, bool incompat) 
	c->disk_sb.sb->version = cpu_to_le16(new_version);

	c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_SB_FEATURES_ALL);



	if (incompat)

	if (incompat) {

		SET_BCH_SB_VERSION_INCOMPAT_ALLOWED(c->disk_sb.sb,

			max(BCH_SB_VERSION_INCOMPAT_ALLOWED(c->disk_sb.sb), new_version));

		c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_FEATURE_incompat_version_field);

	}

}



static int bch2_sb_ext_validate(struct bch_sb *sb, struct bch_sb_field *f,

fs/bcachefs/super-io.h

+4 −7
Original line number Diff line number Diff line
@@ -21,17 +21,14 @@ static inline bool bch2_version_compatible(u16 version) 
void bch2_version_to_text(struct printbuf *, enum bcachefs_metadata_version);

enum bcachefs_metadata_version bch2_latest_compatible_version(enum bcachefs_metadata_version);



void bch2_set_version_incompat(struct bch_fs *, enum bcachefs_metadata_version);

bool bch2_set_version_incompat(struct bch_fs *, enum bcachefs_metadata_version);



static inline bool bch2_request_incompat_feature(struct bch_fs *c,

						 enum bcachefs_metadata_version version)

{

	if (unlikely(version > c->sb.version_incompat)) {

		if (version > c->sb.version_incompat_allowed)

			return false;

		bch2_set_version_incompat(c, version);

	}

	return true;

	return likely(version <= c->sb.version_incompat)

		? true

		: bch2_set_version_incompat(c, version);

}



static inline size_t bch2_sb_field_bytes(struct bch_sb_field *f)