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path: root/drivers/md/dm-thin.c
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Diffstat (limited to 'drivers/md/dm-thin.c')
-rw-r--r--drivers/md/dm-thin.c165
1 files changed, 75 insertions, 90 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 92237b6fa..fc803d50f 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -322,56 +322,6 @@ struct thin_c {
/*----------------------------------------------------------------*/
-/**
- * __blkdev_issue_discard_async - queue a discard with async completion
- * @bdev: blockdev to issue discard for
- * @sector: start sector
- * @nr_sects: number of sectors to discard
- * @gfp_mask: memory allocation flags (for bio_alloc)
- * @flags: BLKDEV_IFL_* flags to control behaviour
- * @parent_bio: parent discard bio that all sub discards get chained to
- *
- * Description:
- * Asynchronously issue a discard request for the sectors in question.
- */
-static int __blkdev_issue_discard_async(struct block_device *bdev, sector_t sector,
- sector_t nr_sects, gfp_t gfp_mask, unsigned long flags,
- struct bio *parent_bio)
-{
- struct request_queue *q = bdev_get_queue(bdev);
- int type = REQ_WRITE | REQ_DISCARD;
- struct bio *bio;
-
- if (!q || !nr_sects)
- return -ENXIO;
-
- if (!blk_queue_discard(q))
- return -EOPNOTSUPP;
-
- if (flags & BLKDEV_DISCARD_SECURE) {
- if (!blk_queue_secdiscard(q))
- return -EOPNOTSUPP;
- type |= REQ_SECURE;
- }
-
- /*
- * Required bio_put occurs in bio_endio thanks to bio_chain below
- */
- bio = bio_alloc(gfp_mask, 1);
- if (!bio)
- return -ENOMEM;
-
- bio_chain(bio, parent_bio);
-
- bio->bi_iter.bi_sector = sector;
- bio->bi_bdev = bdev;
- bio->bi_iter.bi_size = nr_sects << 9;
-
- submit_bio(type, bio);
-
- return 0;
-}
-
static bool block_size_is_power_of_two(struct pool *pool)
{
return pool->sectors_per_block_shift >= 0;
@@ -384,14 +334,55 @@ static sector_t block_to_sectors(struct pool *pool, dm_block_t b)
(b * pool->sectors_per_block);
}
-static int issue_discard(struct thin_c *tc, dm_block_t data_b, dm_block_t data_e,
- struct bio *parent_bio)
+/*----------------------------------------------------------------*/
+
+struct discard_op {
+ struct thin_c *tc;
+ struct blk_plug plug;
+ struct bio *parent_bio;
+ struct bio *bio;
+};
+
+static void begin_discard(struct discard_op *op, struct thin_c *tc, struct bio *parent)
+{
+ BUG_ON(!parent);
+
+ op->tc = tc;
+ blk_start_plug(&op->plug);
+ op->parent_bio = parent;
+ op->bio = NULL;
+}
+
+static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e)
{
+ struct thin_c *tc = op->tc;
sector_t s = block_to_sectors(tc->pool, data_b);
sector_t len = block_to_sectors(tc->pool, data_e - data_b);
- return __blkdev_issue_discard_async(tc->pool_dev->bdev, s, len,
- GFP_NOWAIT, 0, parent_bio);
+ return __blkdev_issue_discard(tc->pool_dev->bdev, s, len,
+ GFP_NOWAIT, REQ_WRITE | REQ_DISCARD, &op->bio);
+}
+
+static void end_discard(struct discard_op *op, int r)
+{
+ if (op->bio) {
+ /*
+ * Even if one of the calls to issue_discard failed, we
+ * need to wait for the chain to complete.
+ */
+ bio_chain(op->bio, op->parent_bio);
+ submit_bio(REQ_WRITE | REQ_DISCARD, op->bio);
+ }
+
+ blk_finish_plug(&op->plug);
+
+ /*
+ * Even if r is set, there could be sub discards in flight that we
+ * need to wait for.
+ */
+ if (r && !op->parent_bio->bi_error)
+ op->parent_bio->bi_error = r;
+ bio_endio(op->parent_bio);
}
/*----------------------------------------------------------------*/
@@ -632,7 +623,7 @@ static void error_retry_list(struct pool *pool)
{
int error = get_pool_io_error_code(pool);
- return error_retry_list_with_code(pool, error);
+ error_retry_list_with_code(pool, error);
}
/*
@@ -1006,24 +997,28 @@ static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping *m)
mempool_free(m, tc->pool->mapping_pool);
}
-static int passdown_double_checking_shared_status(struct dm_thin_new_mapping *m)
+/*----------------------------------------------------------------*/
+
+static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m)
{
/*
* We've already unmapped this range of blocks, but before we
* passdown we have to check that these blocks are now unused.
*/
- int r;
+ int r = 0;
bool used = true;
struct thin_c *tc = m->tc;
struct pool *pool = tc->pool;
dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin;
+ struct discard_op op;
+ begin_discard(&op, tc, m->bio);
while (b != end) {
/* find start of unmapped run */
for (; b < end; b++) {
r = dm_pool_block_is_used(pool->pmd, b, &used);
if (r)
- return r;
+ goto out;
if (!used)
break;
@@ -1036,20 +1031,20 @@ static int passdown_double_checking_shared_status(struct dm_thin_new_mapping *m)
for (e = b + 1; e != end; e++) {
r = dm_pool_block_is_used(pool->pmd, e, &used);
if (r)
- return r;
+ goto out;
if (used)
break;
}
- r = issue_discard(tc, b, e, m->bio);
+ r = issue_discard(&op, b, e);
if (r)
- return r;
+ goto out;
b = e;
}
-
- return 0;
+out:
+ end_discard(&op, r);
}
static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
@@ -1059,20 +1054,21 @@ static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
struct pool *pool = tc->pool;
r = dm_thin_remove_range(tc->td, m->virt_begin, m->virt_end);
- if (r)
+ if (r) {
metadata_operation_failed(pool, "dm_thin_remove_range", r);
+ bio_io_error(m->bio);
- else if (m->maybe_shared)
- r = passdown_double_checking_shared_status(m);
- else
- r = issue_discard(tc, m->data_block, m->data_block + (m->virt_end - m->virt_begin), m->bio);
+ } else if (m->maybe_shared) {
+ passdown_double_checking_shared_status(m);
+
+ } else {
+ struct discard_op op;
+ begin_discard(&op, tc, m->bio);
+ r = issue_discard(&op, m->data_block,
+ m->data_block + (m->virt_end - m->virt_begin));
+ end_discard(&op, r);
+ }
- /*
- * Even if r is set, there could be sub discards in flight that we
- * need to wait for.
- */
- m->bio->bi_error = r;
- bio_endio(m->bio);
cell_defer_no_holder(tc, m->cell);
mempool_free(m, pool->mapping_pool);
}
@@ -1494,17 +1490,6 @@ static void process_discard_cell_no_passdown(struct thin_c *tc,
pool->process_prepared_discard(m);
}
-/*
- * __bio_inc_remaining() is used to defer parent bios's end_io until
- * we _know_ all chained sub range discard bios have completed.
- */
-static inline void __bio_inc_remaining(struct bio *bio)
-{
- bio->bi_flags |= (1 << BIO_CHAIN);
- smp_mb__before_atomic();
- atomic_inc(&bio->__bi_remaining);
-}
-
static void break_up_discard_bio(struct thin_c *tc, dm_block_t begin, dm_block_t end,
struct bio *bio)
{
@@ -1554,13 +1539,13 @@ static void break_up_discard_bio(struct thin_c *tc, dm_block_t begin, dm_block_t
/*
* The parent bio must not complete before sub discard bios are
- * chained to it (see __blkdev_issue_discard_async's bio_chain)!
+ * chained to it (see end_discard's bio_chain)!
*
* This per-mapping bi_remaining increment is paired with
* the implicit decrement that occurs via bio_endio() in
- * process_prepared_discard_{passdown,no_passdown}.
+ * end_discard().
*/
- __bio_inc_remaining(bio);
+ bio_inc_remaining(bio);
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list))
pool->process_prepared_discard(m);
@@ -3899,7 +3884,7 @@ static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
- .version = {1, 18, 0},
+ .version = {1, 19, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
@@ -4273,7 +4258,7 @@ static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type thin_target = {
.name = "thin",
- .version = {1, 18, 0},
+ .version = {1, 19, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,