bcachefs: Check for backpointer bucket_offset >= bucket size

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

diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c
index 114328a..fadb107 100644 (file)
--- a/fs/bcachefs/backpointers.c
+++ b/fs/bcachefs/backpointers.c
@@ -49,13 +49,15 @@ int bch2_backpointer_invalid(struct bch_fs *c, struct bkey_s_c k,
        if (!bch2_dev_exists2(c, bp.k->p.inode))
                return 0;
 
+       struct bch_dev *ca = bch_dev_bkey_exists(c, bp.k->p.inode);
        struct bpos bucket = bp_pos_to_bucket(c, bp.k->p);
        int ret = 0;
 
-       bkey_fsck_err_on(!bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset)),
+       bkey_fsck_err_on((bp.v->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT) >= ca->mi.bucket_size ||
+                        !bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset)),
                         c, err,
-                        backpointer_pos_wrong,
-                        "backpointer at wrong pos");
+                        backpointer_bucket_offset_wrong,
+                        "backpointer bucket_offset wrong");
 fsck_err:
        return ret;
 }

diff --git a/fs/bcachefs/backpointers.h b/fs/bcachefs/backpointers.h
index da012ca..85949b9 100644 (file)
--- a/fs/bcachefs/backpointers.h
+++ b/fs/bcachefs/backpointers.h
@@ -53,14 +53,11 @@ static inline struct bpos bucket_pos_to_bp(const struct bch_fs *c,
                                           u64 bucket_offset)
 {
        struct bch_dev *ca = bch_dev_bkey_exists(c, bucket.inode);
-       struct bpos ret;
-
-       ret = POS(bucket.inode,
-                 (bucket_to_sector(ca, bucket.offset) <<
-                  MAX_EXTENT_COMPRESS_RATIO_SHIFT) + bucket_offset);
+       struct bpos ret = POS(bucket.inode,
+                             (bucket_to_sector(ca, bucket.offset) <<
+                              MAX_EXTENT_COMPRESS_RATIO_SHIFT) + bucket_offset);
 
        EBUG_ON(!bkey_eq(bucket, bp_pos_to_bucket(c, ret)));
-
        return ret;
 }
 

diff --git a/fs/bcachefs/sb-errors_types.h b/fs/bcachefs/sb-errors_types.h
index 5b600c6..4ca6e7b 100644 (file)
--- a/fs/bcachefs/sb-errors_types.h
+++ b/fs/bcachefs/sb-errors_types.h
@@ -130,7 +130,7 @@
        x(bucket_gens_nonzero_for_invalid_buckets,              122)    \
        x(need_discard_freespace_key_to_invalid_dev_bucket,     123)    \
        x(need_discard_freespace_key_bad,                       124)    \
-       x(backpointer_pos_wrong,                                125)    \
+       x(backpointer_bucket_offset_wrong,                      125)    \
        x(backpointer_to_missing_device,                        126)    \
        x(backpointer_to_missing_alloc,                         127)    \
        x(backpointer_to_missing_ptr,                           128)    \