-/*
- * This allows us to do IO even on the odd last sectors
- * of a device, even if the block size is some multiple
- * of the physical sector size.
- *
- * We'll just truncate the bio to the size of the device,
- * and clear the end of the buffer head manually.
- *
- * Truly out-of-range accesses will turn into actual IO
- * errors, this only handles the "we need to be able to
- * do IO at the final sector" case.
- */
-void guard_bio_eod(struct bio *bio)
-{
- sector_t maxsector;
- struct hd_struct *part;
-
- rcu_read_lock();
- part = __disk_get_part(bio->bi_disk, bio->bi_partno);
- if (part)
- maxsector = part_nr_sects_read(part);
- else
- maxsector = get_capacity(bio->bi_disk);
- rcu_read_unlock();
-
- if (!maxsector)
- return;
-
- /*
- * If the *whole* IO is past the end of the device,
- * let it through, and the IO layer will turn it into
- * an EIO.
- */
- if (unlikely(bio->bi_iter.bi_sector >= maxsector))
- return;
-
- maxsector -= bio->bi_iter.bi_sector;
- if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
- return;
-
- bio_truncate(bio, maxsector << 9);
-}
-