Must call blk_queue_split() otherwise queue_limits for abnormal requests
(e.g. discard, writesame, etc) won't be imposed.
In addition, add dm_queue_split() to simplify DM specific splitting that
is needed for targets that impose ti->max_io_len.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm.c | 93 ++++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 66 insertions(+), 27 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 515e6af9bed2..7a774fcd0194 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1533,6 +1533,22 @@ static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)
return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti), false);
}
+static bool is_abnormal_io(struct bio *bio)
+{
+ bool r = false;
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_SAME:
+ case REQ_OP_WRITE_ZEROES:
+ r = true;
+ break;
+ }
+
+ return r;
+}
+
static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti,
int *result)
{
@@ -1565,7 +1581,7 @@ static int __split_and_process_non_flush(struct clone_info *ci)
if (!dm_target_is_valid(ti))
return -EIO;
- if (unlikely(__process_abnormal_io(ci, ti, &r)))
+ if (__process_abnormal_io(ci, ti, &r))
return r;
len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
@@ -1601,13 +1617,6 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
blk_qc_t ret = BLK_QC_T_NONE;
int error = 0;
- if (unlikely(!map)) {
- bio_io_error(bio);
- return ret;
- }
-
- blk_queue_split(md->queue, &bio);
-
init_clone_info(&ci, md, map, bio);
if (bio->bi_opf & REQ_PREFLUSH) {
@@ -1675,18 +1684,13 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
* Optimized variant of __split_and_process_bio that leverages the
* fact that targets that use it do _not_ have a need to split bios.
*/
-static blk_qc_t __process_bio(struct mapped_device *md,
- struct dm_table *map, struct bio *bio)
+static blk_qc_t __process_bio(struct mapped_device *md, struct dm_table *map,
+ struct bio *bio, struct dm_target *ti)
{
struct clone_info ci;
blk_qc_t ret = BLK_QC_T_NONE;
int error = 0;
- if (unlikely(!map)) {
- bio_io_error(bio);
- return ret;
- }
-
init_clone_info(&ci, md, map, bio);
if (bio->bi_opf & REQ_PREFLUSH) {
@@ -1704,21 +1708,11 @@ static blk_qc_t __process_bio(struct mapped_device *md,
error = __send_empty_flush(&ci);
/* dec_pending submits any data associated with flush */
} else {
- struct dm_target *ti = md->immutable_target;
struct dm_target_io *tio;
- /*
- * Defend against IO still getting in during teardown
- * - as was seen for a time with nvme-fcloop
- */
- if (WARN_ON_ONCE(!ti || !dm_target_is_valid(ti))) {
- error = -EIO;
- goto out;
- }
-
ci.bio = bio;
ci.sector_count = bio_sectors(bio);
- if (unlikely(__process_abnormal_io(&ci, ti, &error)))
+ if (__process_abnormal_io(&ci, ti, &error))
goto out;
tio = alloc_tio(&ci, ti, 0, GFP_NOIO);
@@ -1730,11 +1724,56 @@ static blk_qc_t __process_bio(struct mapped_device *md,
return ret;
}
+static void dm_queue_split(struct mapped_device *md, struct dm_target *ti, struct bio **bio)
+{
+ unsigned len, sector_count;
+
+ sector_count = bio_sectors(*bio);
+ len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count);
+
+ if (sector_count > len) {
+ struct bio *split = bio_split(*bio, len, GFP_NOIO, &md->queue->bio_split);
+
+ bio_chain(split, *bio);
+ trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector);
+ generic_make_request(*bio);
+ *bio = split;
+ }
+}
+
static blk_qc_t dm_process_bio(struct mapped_device *md,
struct dm_table *map, struct bio *bio)
{
+ blk_qc_t ret = BLK_QC_T_NONE;
+ struct dm_target *ti = md->immutable_target;
+
+ if (unlikely(!map)) {
+ bio_io_error(bio);
+ return ret;
+ }
+
+ if (!ti) {
+ ti = dm_table_find_target(map, bio->bi_iter.bi_sector);
+ if (unlikely(!ti || !dm_target_is_valid(ti))) {
+ bio_io_error(bio);
+ return ret;
+ }
+ }
+
+ /*
+ * If in ->make_request_fn we need to use blk_queue_split(), otherwise
+ * queue_limits for abnormal requests (e.g. discard, writesame, etc)
+ * won't be imposed.
+ */
+ if (current->bio_list) {
+ if (is_abnormal_io(bio))
+ blk_queue_split(md->queue, &bio);
+ else
+ dm_queue_split(md, ti, &bio);
+ }
+
if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
- return __process_bio(md, map, bio);
+ return __process_bio(md, map, bio, ti);
else
return __split_and_process_bio(md, map, bio);
}
--
2.15.0
--
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