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-rw-r--r--drivers/md/dm-table.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index cb8380c9767f..451c3bb176d2 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -362,6 +362,7 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
+ struct request_queue *q;
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
sector_t dev_size =
@@ -370,6 +371,22 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
limits->logical_block_size >> SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
+ /*
+ * Some devices exist without request functions,
+ * such as loop devices not yet bound to backing files.
+ * Forbid the use of such devices.
+ */
+ q = bdev_get_queue(bdev);
+ if (!q || !q->make_request_fn) {
+ DMWARN("%s: %s is not yet initialised: "
+ "start=%llu, len=%llu, dev_size=%llu",
+ dm_device_name(ti->table->md), bdevname(bdev, b),
+ (unsigned long long)start,
+ (unsigned long long)len,
+ (unsigned long long)dev_size);
+ return 1;
+ }
+
if (!dev_size)
return 0;
@@ -1346,7 +1363,8 @@ bool dm_table_supports_discards(struct dm_table *t)
return 0;
/*
- * Ensure that at least one underlying device supports discards.
+ * Unless any target used by the table set discards_supported,
+ * require at least one underlying device to support discards.
* t->devices includes internal dm devices such as mirror logs
* so we need to use iterate_devices here, which targets
* supporting discard must provide.
@@ -1354,6 +1372,9 @@ bool dm_table_supports_discards(struct dm_table *t)
while (i < dm_table_get_num_targets(t)) {
ti = dm_table_get_target(t, i++);
+ if (ti->discards_supported)
+ return 1;
+
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, device_discard_capable, NULL))
return 1;
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