btrfs-calc-size show following warning:
# btrfs-calc-size /dev/sda6
Calculating size of root tree
...
extent_io.c:582: free_extent_buffer: Assertion `eb->refs < 0` failed.
./btrfs-calc-size[0x41d642]
./btrfs-calc-size(free_extent_buffer+0x70)[0x41e1c1]
./btrfs-calc-size(btrfs_free_fs_root+0x11)[0x40e1e8]
./btrfs-calc-size[0x40e215]
./btrfs-calc-size(rb_free_nodes+0x1d)[0x4326fe]
./btrfs-calc-size(close_ctree+0x3f3)[0x40f9ea]
./btrfs-calc-size(main+0x200)[0x431b4e]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x3858621d65]
./btrfs-calc-size[0x407009]
Reason:
path in calc_root_size() is only used to save node data,
it don't hold ref_cnt for each eb in.
Using btrfs_free_path() to free path will reduce these eb
again, and cause many problems, as negative ref_cnt or
invalid memory access.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
free(seek);
}
- btrfs_free_path(path);
+ /*
+ * We only use path to save node data in iterating,
+ * without holding eb's ref_cnt in path.
+ * Don't use btrfs_free_path() here, it will free these
+ * eb again, and cause many problems, as negative ref_cnt
+ * or invalid memory access.
+ */
+ free(path);
return ret;
}