On Tue, Dec 30, 2008 at 11:15 AM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote: > 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 Got the answer here http://lkml.indiana.edu/hypermail/linux/kernel/0204.1/0440.html Thanks - Manish > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
