Linux C ext2fs_write_inode_full failing to write

Question

after successfully reading the file inode with this:

retval = ext2fs_read_inode_full(current_fs, inode, inode_buf, EXT2_INODE_SIZE(current_fs->super));
if (retval) {
    fprintf(stderr, "Failed to read inode\n");
    free(fs);
    free(inode_buf);
    return retval;
}

(At this point I have verified the inode contains the correct data of the file in question)

I immediately attempt to write it back with this :

  retval = ext2fs_write_inode_full(current_fs, inode, inode_buf, EXT2_INODE_SIZE(current_fs->super));
  if (retval) {
      fprintf(stderr, "Failed to write inode %d\n", retval);
  }

(Of course it's my intention to change some date values in the inode before writing back)

But ext2fs_write_inode_full returns an error value 2133571349.

The program executes with root privileged!

Answer 1

The issue turned out to be the way crtime was opening the FS with ext2fs_open.

I needed to pass the EXT2_FLAG_RW flag otherwise the open is by default read only.