bcachefs: Revert directory i_size

This turned out to have several bugs, which were missed because the fsck
code wasn't properly reporting errors - whoops.

Kicking it out for now, hopefully it can make 6.15.

Cc: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/dirent.h

@@ -31,11 +31,6 @@ static inline unsigned dirent_val_u64s(unsigned len)
 			    sizeof(u64));
 }
 
-static inline unsigned int dirent_occupied_size(const struct qstr *name)
-{
-	return (BKEY_U64s + dirent_val_u64s(name->len)) * sizeof(u64);
-}
-
 int bch2_dirent_read_target(struct btree_trans *, subvol_inum,
 			    struct bkey_s_c_dirent, subvol_inum *);
 

fs/bcachefs/fs-common.c

@@ -152,7 +152,6 @@ int bch2_create_trans(struct btree_trans *trans,
 		if (is_subdir_for_nlink(new_inode))
 			dir_u->bi_nlink++;
 		dir_u->bi_mtime = dir_u->bi_ctime = now;
-		dir_u->bi_size += dirent_occupied_size(name);
 
 		ret = bch2_inode_write(trans, &dir_iter, dir_u);
 		if (ret)
@@ -221,7 +220,6 @@ int bch2_link_trans(struct btree_trans *trans,
 	}
 
 	dir_u->bi_mtime = dir_u->bi_ctime = now;
-	dir_u->bi_size += dirent_occupied_size(name);
 
 	dir_hash = bch2_hash_info_init(c, dir_u);
 
@@ -324,7 +322,6 @@ int bch2_unlink_trans(struct btree_trans *trans,
 
 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
-	dir_u->bi_size	-= dirent_occupied_size(name);
 
 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
 				    &dir_hash, &dirent_iter,
@@ -463,14 +460,6 @@ int bch2_rename_trans(struct btree_trans *trans,
 		goto err;
 	}
 
-	if (mode == BCH_RENAME) {
-		src_dir_u->bi_size -= dirent_occupied_size(src_name);
-		dst_dir_u->bi_size += dirent_occupied_size(dst_name);
-	}
-
-	if (mode == BCH_RENAME_OVERWRITE)
-		src_dir_u->bi_size -= dirent_occupied_size(src_name);
-
 	if (src_inode_u->bi_parent_subvol)
 		src_inode_u->bi_parent_subvol = dst_dir.subvol;
 

fs/bcachefs/fsck.c

@@ -1978,31 +1978,10 @@ static int check_subdir_count_notnested(struct btree_trans *trans, struct inode_
 	return ret;
 }
 
-static int check_dir_i_size_notnested(struct btree_trans *trans, struct inode_walker *w)
-{
-	struct bch_fs *c = trans->c;
-	int ret = 0;
-
-	darray_for_each(w->inodes, i)
-		if (fsck_err_on(i->inode.bi_size != i->i_size,
-				trans, inode_dir_wrong_nlink,
-				"directory %llu:%u with wrong i_size: got %llu, should be %llu",
-				w->last_pos.inode, i->snapshot, i->inode.bi_size, i->i_size)) {
-			i->inode.bi_size = i->i_size;
-			ret = bch2_fsck_write_inode(trans, &i->inode);
-			if (ret)
-				break;
-		}
-fsck_err:
-	bch_err_fn(c, ret);
-	return ret;
-}
-
 static int check_subdir_dirents_count(struct btree_trans *trans, struct inode_walker *w)
 {
 	u32 restart_count = trans->restart_count;
 	return check_subdir_count_notnested(trans, w) ?:
-		check_dir_i_size_notnested(trans, w) ?:
 		trans_was_restarted(trans, restart_count);
 }
 

fs/bcachefs/sb-downgrade.c

@@ -90,10 +90,7 @@
 	  BIT_ULL(BCH_RECOVERY_PASS_check_allocations),		\
 	  BCH_FSCK_ERR_accounting_mismatch,			\
 	  BCH_FSCK_ERR_accounting_key_replicas_nr_devs_0,	\
-	  BCH_FSCK_ERR_accounting_key_junk_at_end)		\
-	x(directory_size,					\
-	  BIT_ULL(BCH_RECOVERY_PASS_check_dirents),		\
-	  BCH_FSCK_ERR_directory_size_mismatch)			\
+	  BCH_FSCK_ERR_accounting_key_junk_at_end)
 
 #define DOWNGRADE_TABLE()					\
 	x(bucket_stripe_sectors,				\