block: Introduce new bio_split()
The new bio_split() can split arbitrary bios - it's not restricted to
single page bios, like the old bio_split() (previously renamed to
bio_pair_split()). It also has different semantics - it doesn't allocate
a struct bio_pair, leaving it up to the caller to handle completions.
Then convert the existing bio_pair_split() users to the new bio_split()
- and also nvme, which was open coding bio splitting.
(We have to take that BUG_ON() out of bio_integrity_trim() because this
bio_split() needs to use it, and there's no reason it has to be used on
bios marked as cloned; BIO_CLONED doesn't seem to have clearly
documented semantics anyways.)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Neil Brown <neilb@suse.de>
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index e9b53e9..56f534b 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -288,65 +288,65 @@
static void linear_make_request(struct mddev *mddev, struct bio *bio)
{
+ char b[BDEVNAME_SIZE];
struct dev_info *tmp_dev;
- sector_t start_sector;
+ struct bio *split;
+ sector_t start_sector, end_sector, data_offset;
if (unlikely(bio->bi_rw & REQ_FLUSH)) {
md_flush_request(mddev, bio);
return;
}
- rcu_read_lock();
- tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector);
- start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+ do {
+ rcu_read_lock();
-
- if (unlikely(bio->bi_iter.bi_sector >= (tmp_dev->end_sector)
- || (bio->bi_iter.bi_sector < start_sector))) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_ERR
- "md/linear:%s: make_request: Sector %llu out of bounds on "
- "dev %s: %llu sectors, offset %llu\n",
- mdname(mddev),
- (unsigned long long)bio->bi_iter.bi_sector,
- bdevname(tmp_dev->rdev->bdev, b),
- (unsigned long long)tmp_dev->rdev->sectors,
- (unsigned long long)start_sector);
- rcu_read_unlock();
- bio_io_error(bio);
- return;
- }
- if (unlikely(bio_end_sector(bio) > tmp_dev->end_sector)) {
- /* This bio crosses a device boundary, so we have to
- * split it.
- */
- struct bio_pair *bp;
- sector_t end_sector = tmp_dev->end_sector;
+ tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector);
+ start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+ end_sector = tmp_dev->end_sector;
+ data_offset = tmp_dev->rdev->data_offset;
+ bio->bi_bdev = tmp_dev->rdev->bdev;
rcu_read_unlock();
- bp = bio_pair_split(bio, end_sector - bio->bi_iter.bi_sector);
+ if (unlikely(bio->bi_iter.bi_sector >= end_sector ||
+ bio->bi_iter.bi_sector < start_sector))
+ goto out_of_bounds;
- linear_make_request(mddev, &bp->bio1);
- linear_make_request(mddev, &bp->bio2);
- bio_pair_release(bp);
- return;
- }
-
- bio->bi_bdev = tmp_dev->rdev->bdev;
- bio->bi_iter.bi_sector = bio->bi_iter.bi_sector - start_sector
- + tmp_dev->rdev->data_offset;
- rcu_read_unlock();
+ if (unlikely(bio_end_sector(bio) > end_sector)) {
+ /* This bio crosses a device boundary, so we have to
+ * split it.
+ */
+ split = bio_split(bio, end_sector -
+ bio->bi_iter.bi_sector,
+ GFP_NOIO, fs_bio_set);
+ bio_chain(split, bio);
+ } else {
+ split = bio;
+ }
- if (unlikely((bio->bi_rw & REQ_DISCARD) &&
- !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) {
- /* Just ignore it */
- bio_endio(bio, 0);
- return;
- }
+ split->bi_iter.bi_sector = split->bi_iter.bi_sector -
+ start_sector + data_offset;
- generic_make_request(bio);
+ if (unlikely((split->bi_rw & REQ_DISCARD) &&
+ !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) {
+ /* Just ignore it */
+ bio_endio(split, 0);
+ } else
+ generic_make_request(split);
+ } while (split != bio);
+ return;
+
+out_of_bounds:
+ printk(KERN_ERR
+ "md/linear:%s: make_request: Sector %llu out of bounds on "
+ "dev %s: %llu sectors, offset %llu\n",
+ mdname(mddev),
+ (unsigned long long)bio->bi_iter.bi_sector,
+ bdevname(tmp_dev->rdev->bdev, b),
+ (unsigned long long)tmp_dev->rdev->sectors,
+ (unsigned long long)start_sector);
+ bio_io_error(bio);
}
static void linear_status (struct seq_file *seq, struct mddev *mddev)