Prepare for full barrier implementation - remove the simple one
Signed-off-by: Milan Broz <mbroz@xxxxxxxxxx>
---
drivers/md/dm-linear.c | 1 -
drivers/md/dm-table.c | 19 -------------------
drivers/md/dm.c | 15 ++++++++++-----
drivers/md/dm.h | 1 -
include/linux/device-mapper.h | 1 -
5 files changed, 10 insertions(+), 27 deletions(-)
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index bfa107f..79fb53e 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -142,7 +142,6 @@ static struct target_type linear_target = {
.status = linear_status,
.ioctl = linear_ioctl,
.merge = linear_merge,
- .features = DM_TARGET_SUPPORTS_BARRIERS,
};
int __init dm_linear_init(void)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 2fd66c3..d599143 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -52,8 +52,6 @@ struct dm_table {
sector_t *highs;
struct dm_target *targets;
- unsigned barriers_supported:1;
-
/*
* Indicates the rw permissions for the new logical
* device. This should be a combination of FMODE_READ
@@ -243,7 +241,6 @@ int dm_table_create(struct dm_table **result, fmode_t mode,
INIT_LIST_HEAD(&t->devices);
atomic_set(&t->holders, 0);
- t->barriers_supported = 1;
if (!num_targets)
num_targets = KEYS_PER_NODE;
@@ -749,10 +746,6 @@ int dm_table_add_target(struct dm_table *t, const char *type,
/* FIXME: the plan is to combine high here and then have
* the merge fn apply the target level restrictions. */
combine_restrictions_low(&t->limits, &tgt->limits);
-
- if (!(tgt->type->features & DM_TARGET_SUPPORTS_BARRIERS))
- t->barriers_supported = 0;
-
return 0;
bad:
@@ -797,12 +790,6 @@ int dm_table_complete(struct dm_table *t)
check_for_valid_limits(&t->limits);
- /*
- * We only support barriers if there is exactly one underlying device.
- */
- if (!list_is_singular(&t->devices))
- t->barriers_supported = 0;
-
/* how many indexes will the btree have ? */
leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
@@ -1017,12 +1004,6 @@ struct mapped_device *dm_table_get_md(struct dm_table *t)
return t->md;
}
-int dm_table_barrier_ok(struct dm_table *t)
-{
- return t->barriers_supported;
-}
-EXPORT_SYMBOL(dm_table_barrier_ok);
-
EXPORT_SYMBOL(dm_vcalloc);
EXPORT_SYMBOL(dm_get_device);
EXPORT_SYMBOL(dm_put_device);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 51ba1db..a9aa699 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -838,11 +838,7 @@ static int __split_bio(struct mapped_device *md, struct bio *bio)
ci.map = dm_get_table(md);
if (unlikely(!ci.map))
return -EIO;
- if (unlikely(bio_barrier(bio) && !dm_table_barrier_ok(ci.map))) {
- dm_table_put(ci.map);
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
+
ci.md = md;
ci.bio = bio;
ci.io = alloc_io(md);
@@ -926,6 +922,15 @@ static int dm_request(struct request_queue *q, struct bio *bio)
struct mapped_device *md = q->queuedata;
int cpu;
+ /*
+ * There is no use in forwarding any barrier request since we can't
+ * guarantee it is (or can be) handled by the targets correctly.
+ */
+ if (unlikely(bio_barrier(bio))) {
+ bio_endio(bio, -EOPNOTSUPP);
+ return 0;
+ }
+
down_read(&md->io_lock);
cpu = part_stat_lock();
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 20194e0..7e1af9b 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -52,7 +52,6 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits);
* To check the return value from dm_table_find_target().
*/
#define dm_target_is_valid(t) ((t)->table)
-int dm_table_barrier_ok(struct dm_table *t);
/*-----------------------------------------------------------------
* A registry of target types.
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 8209e08..27dfba2 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -116,7 +116,6 @@ void dm_put_device(struct dm_target *ti, struct dm_dev *d);
/*
* Target features
*/
-#define DM_TARGET_SUPPORTS_BARRIERS 0x00000001
struct target_type {
uint64_t features;
--
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