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dm: remove useless loop in __split_and_process_bio 

Remove useless "while" loop. If the condition ci.sector_count && !error is
true, we go to a branch that ends with "break". If this condition is
false, the "while" loop will not be executed again. So, the loop can't be
executed more than once.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mikulas Patocka 2021-03-01 04:58:43 -05:00 committed by Mike Snitzer
parent c40819f267
commit 8615cb65bd
1 changed files with 27 additions and 30 deletions
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57
drivers/md/dm.c
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@ -1641,38 +1641,35 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
} else {
ci.bio = bio;
ci.sector_count = bio_sectors(bio);
while (ci.sector_count && !error) {
error = __split_and_process_non_flush(&ci);
if (ci.sector_count && !error) {
/*
* Remainder must be passed to submit_bio_noacct()
* so that it gets handled *after* bios already submitted
* have been completely processed.
* We take a clone of the original to store in
* ci.io->orig_bio to be used by end_io_acct() and
* for dec_pending to use for completion handling.
*/
struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,
GFP_NOIO, &md->queue->bio_split);
ci.io->orig_bio = b;
error = __split_and_process_non_flush(&ci);
if (ci.sector_count && !error) {
/*
* Remainder must be passed to submit_bio_noacct()
* so that it gets handled *after* bios already submitted
* have been completely processed.
* We take a clone of the original to store in
* ci.io->orig_bio to be used by end_io_acct() and
* for dec_pending to use for completion handling.
*/
struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,
GFP_NOIO, &md->queue->bio_split);
ci.io->orig_bio = b;
/*
* Adjust IO stats for each split, otherwise upon queue
* reentry there will be redundant IO accounting.
* NOTE: this is a stop-gap fix, a proper fix involves
* significant refactoring of DM core's bio splitting
* (by eliminating DM's splitting and just using bio_split)
*/
part_stat_lock();
__dm_part_stat_sub(dm_disk(md)->part0,
sectors[op_stat_group(bio_op(bio))], ci.sector_count);
part_stat_unlock();
/*
* Adjust IO stats for each split, otherwise upon queue
* reentry there will be redundant IO accounting.
* NOTE: this is a stop-gap fix, a proper fix involves
* significant refactoring of DM core's bio splitting
* (by eliminating DM's splitting and just using bio_split)
*/
part_stat_lock();
__dm_part_stat_sub(dm_disk(md)->part0,
sectors[op_stat_group(bio_op(bio))], ci.sector_count);
part_stat_unlock();
bio_chain(b, bio);
trace_block_split(b, bio->bi_iter.bi_sector);
ret = submit_bio_noacct(bio);
break;
}
bio_chain(b, bio);
trace_block_split(b, bio->bi_iter.bi_sector);
ret = submit_bio_noacct(bio);
}
}