diff options
author | Christoph Hellwig <hch@lst.de> | 2020-03-25 18:48:40 +0300 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2020-03-25 18:50:08 +0300 |
commit | 29125ed624eeb3ac2eb7bca313a8de29c1c84dcd (patch) | |
tree | 1d728350d5aef28aa3ac2a343d8768292427d066 /block | |
parent | 1b4d4dbdaeb7087122a39d3fb9ae32487e001b6c (diff) |
block: move guard_bio_eod to bio.c
This is bio layer functionality and not related to buffer heads.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r-- | block/bio.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c index bc9152977bf0..11e6aac35092 100644 --- a/block/bio.c +++ b/block/bio.c @@ -589,6 +589,49 @@ void bio_truncate(struct bio *bio, unsigned new_size) } /** + * guard_bio_eod - truncate a BIO to fit the block device + * @bio: bio to truncate + * + * 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 + * I/O errors, this only handles the "we need to be able to do I/O 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); +} + +/** * bio_put - release a reference to a bio * @bio: bio to release reference to * |