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-rw-r--r--drivers/md/dm-ioctl.c15
-rw-r--r--drivers/md/dm.c62
-rw-r--r--drivers/md/dm.h5
3 files changed, 62 insertions, 20 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 6a6d475..feb64d6 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -274,6 +274,10 @@ retry:
up_write(&_hash_lock);
dm_put(md);
+ if (likely(keep_open_devices))
+ dm_destroy(md);
+ else
+ dm_destroy_immediate(md);
/*
* Some mapped devices may be using other mapped
@@ -644,17 +648,19 @@ static int dev_create(struct dm_ioctl *param, size_t param_size)
return r;
r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
- if (r)
- goto out;
+ if (r) {
+ dm_put(md);
+ dm_destroy(md);
+ return r;
+ }
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
__dev_status(md, param);
-out:
dm_put(md);
- return r;
+ return 0;
}
/*
@@ -748,6 +754,7 @@ static int dev_remove(struct dm_ioctl *param, size_t param_size)
param->flags |= DM_UEVENT_GENERATED_FLAG;
dm_put(md);
+ dm_destroy(md);
return 0;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ba6934c..a503b95 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -20,6 +20,7 @@
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/hdreg.h>
+#include <linux/delay.h>
#include <trace/events/block.h>
@@ -2171,6 +2172,7 @@ void dm_set_mdptr(struct mapped_device *md, void *ptr)
void dm_get(struct mapped_device *md)
{
atomic_inc(&md->holders);
+ BUG_ON(test_bit(DMF_FREEING, &md->flags));
}
const char *dm_device_name(struct mapped_device *md)
@@ -2179,27 +2181,55 @@ const char *dm_device_name(struct mapped_device *md)
}
EXPORT_SYMBOL_GPL(dm_device_name);
-void dm_put(struct mapped_device *md)
+static void __dm_destroy(struct mapped_device *md, bool wait)
{
struct dm_table *map;
- BUG_ON(test_bit(DMF_FREEING, &md->flags));
+ might_sleep();
- if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
- map = dm_get_live_table(md);
- idr_replace(&_minor_idr, MINOR_ALLOCED,
- MINOR(disk_devt(dm_disk(md))));
- set_bit(DMF_FREEING, &md->flags);
- spin_unlock(&_minor_lock);
- if (!dm_suspended_md(md)) {
- dm_table_presuspend_targets(map);
- dm_table_postsuspend_targets(map);
- }
- dm_sysfs_exit(md);
- dm_table_put(map);
- dm_table_destroy(__unbind(md));
- free_dev(md);
+ spin_lock(&_minor_lock);
+ map = dm_get_live_table(md);
+ idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
+ set_bit(DMF_FREEING, &md->flags);
+ spin_unlock(&_minor_lock);
+
+ if (!dm_suspended_md(md)) {
+ dm_table_presuspend_targets(map);
+ dm_table_postsuspend_targets(map);
}
+
+ /*
+ * Rare, but there may be I/O requests still going to complete,
+ * for example. Wait for all references to disappear.
+ * No one should increment the reference count of the mapped_device,
+ * after the mapped_device state becomes DMF_FREEING.
+ */
+ if (wait)
+ while (atomic_read(&md->holders))
+ msleep(1);
+ else if (atomic_read(&md->holders))
+ DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
+ dm_device_name(md), atomic_read(&md->holders));
+
+ dm_sysfs_exit(md);
+ dm_table_put(map);
+ dm_table_destroy(__unbind(md));
+ free_dev(md);
+}
+
+void dm_destroy(struct mapped_device *md)
+{
+ __dm_destroy(md, true);
+}
+
+void dm_destroy_immediate(struct mapped_device *md)
+{
+ __dm_destroy(md, false);
+}
+
+void dm_put(struct mapped_device *md)
+{
+ atomic_dec(&md->holders);
}
EXPORT_SYMBOL_GPL(dm_put);
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index bad1724..8223671 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -122,6 +122,11 @@ void dm_linear_exit(void);
int dm_stripe_init(void);
void dm_stripe_exit(void);
+/*
+ * mapped_device operations
+ */
+void dm_destroy(struct mapped_device *md);
+void dm_destroy_immediate(struct mapped_device *md);
int dm_open_count(struct mapped_device *md);
int dm_lock_for_deletion(struct mapped_device *md);
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