From 692d0eb9e02cf81fb387ff891f53840db2f3110a Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 9 Apr 2009 00:27:13 +0100 Subject: dm: remove limited barrier support Prepare for full barrier implementation: first remove the restricted support. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- 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 bfa107f59d9..79fb53e51c7 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 02d0b489fad..429b50b975d 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; @@ -751,10 +748,6 @@ 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: @@ -799,12 +792,6 @@ 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); @@ -1059,12 +1046,6 @@ 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 25d86e2c01f..ab3b5d84df6 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -851,11 +851,7 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) bio_io_error(bio); return; } - if (unlikely(bio_barrier(bio) && !dm_table_barrier_ok(ci.map))) { - dm_table_put(ci.map); - bio_endio(bio, -EOPNOTSUPP); - return; - } + ci.md = md; ci.bio = bio; ci.io = alloc_io(md); @@ -937,6 +933,15 @@ 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 b48397c0abb..a31506d93e9 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 66ec05a5795..ded2d7c4266 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; -- cgit v1.2.3