Commit 92c7789a authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Validate bch_sb.offset field 



This was missed - but it needs to be correct for the superblock recovery
tool that scans the start and end of the device for backup superblocks:
we don't want to pick up superblocks that belong to a different
partition that starts at a different offset.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 8bd875ae

fs/bcachefs/errcode.h

+1 −0
Original line number Diff line number Diff line
@@ -231,6 +231,7 @@ 
	x(BCH_ERR_invalid_sb,		invalid_sb_csum)			\

	x(BCH_ERR_invalid_sb,		invalid_sb_block_size)			\

	x(BCH_ERR_invalid_sb,		invalid_sb_uuid)			\

	x(BCH_ERR_invalid_sb,		invalid_sb_offset)			\

	x(BCH_ERR_invalid_sb,		invalid_sb_too_many_members)		\

	x(BCH_ERR_invalid_sb,		invalid_sb_dev_idx)			\

	x(BCH_ERR_invalid_sb,		invalid_sb_time_precision)		\

fs/bcachefs/super-io.c

+11 −3
Original line number Diff line number Diff line
@@ -365,7 +365,8 @@ static int bch2_sb_compatible(struct bch_sb *sb, struct printbuf *out) 
	return 0;

}



int bch2_sb_validate(struct bch_sb *sb, enum bch_validate_flags flags, struct printbuf *out)

int bch2_sb_validate(struct bch_sb *sb, u64 read_offset,

		     enum bch_validate_flags flags, struct printbuf *out)

{

	struct bch_sb_field_members_v1 *mi;

	enum bch_opt_id opt_id;
@@ -409,6 +410,13 @@ int bch2_sb_validate(struct bch_sb *sb, enum bch_validate_flags flags, struct pr 
		return -BCH_ERR_invalid_sb_uuid;

	}



	if (!(flags & BCH_VALIDATE_write) &&

	    le64_to_cpu(sb->offset) != read_offset) {

		prt_printf(out, "Bad sb offset (got %llu, read from %llu)",

			   le64_to_cpu(sb->offset), read_offset);

		return -BCH_ERR_invalid_sb_offset;

	}



	if (!sb->nr_devices ||

	    sb->nr_devices > BCH_SB_MEMBERS_MAX) {

		prt_printf(out, "Bad number of member devices %u (max %u)",
@@ -888,7 +896,7 @@ static int __bch2_read_super(const char *path, struct bch_opts *opts, 


	sb->have_layout = true;



	ret = bch2_sb_validate(sb->sb, 0, &err);

	ret = bch2_sb_validate(sb->sb, offset, 0, &err);

	if (ret) {

		bch2_print_opts(opts, KERN_ERR "bcachefs (%s): error validating superblock: %s\n",

				path, err.buf);
@@ -1045,7 +1053,7 @@ int bch2_write_super(struct bch_fs *c) 
	darray_for_each(online_devices, ca) {

		printbuf_reset(&err);



		ret = bch2_sb_validate((*ca)->disk_sb.sb, BCH_VALIDATE_write, &err);

		ret = bch2_sb_validate((*ca)->disk_sb.sb, 0, BCH_VALIDATE_write, &err);

		if (ret) {

			bch2_fs_inconsistent(c, "sb invalid before write: %s", err.buf);

			goto out;

fs/bcachefs/super-io.h

+1 −1
Original line number Diff line number Diff line
@@ -92,7 +92,7 @@ int bch2_sb_from_fs(struct bch_fs *, struct bch_dev *); 
void bch2_free_super(struct bch_sb_handle *);

int bch2_sb_realloc(struct bch_sb_handle *, unsigned);



int bch2_sb_validate(struct bch_sb *, enum bch_validate_flags, struct printbuf *);

int bch2_sb_validate(struct bch_sb *, u64, enum bch_validate_flags, struct printbuf *);



int bch2_read_super(const char *, struct bch_opts *, struct bch_sb_handle *);

int bch2_read_super_silent(const char *, struct bch_opts *, struct bch_sb_handle *);