Hi,

I was trying to understand the purpose of the below check for
validating rec_len in the function ext2_add_link(). Before reaching
line 515 we call ext2_get_page() which checks for valid entries on the
page and thus validates the rec_len too. And then we call the
lock_page(), so is this check redundant or to avoid cases when
something could have changed on the page between the lines 497 and 501
?

ext2_add_link() {

........        
497            page = ext2_get_page(dir, n, 0);
499                     if (IS_ERR(page))
500                     goto out;
501                 lock_page(page);
.........
515                     if (de->rec_len == 0) {
516                             ext2_error(dir->i_sb, __func__,
517                                     "zero-length directory entry");
518                             err = -EIO;
519                             goto out_unlock;
520                     }

..........
}

Thanks -
Manish

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