diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 6a6d475f8e80..feb64d65fbfb 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 ba6934c3e2c5..a503b95ecbfb 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -20,6 +20,7 @@ #include #include #include +#include #include @@ -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 bad1724d4869..8223671e4901 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);