From 2c140a246dc0bc085b98eddde978060fcec1080c Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 1 Nov 2013 18:27:41 -0400 Subject: dm: allow remove to be deferred This patch allows the removal of an open device to be deferred until it is closed. (Previously such a removal attempt would fail.) The deferred remove functionality is enabled by setting the flag DM_DEFERRED_REMOVE in the ioctl structure on DM_DEV_REMOVE or DM_REMOVE_ALL ioctl. On return from DM_DEV_REMOVE, the flag DM_DEFERRED_REMOVE indicates if the device was removed immediately or flagged to be removed on close - if the flag is clear, the device was removed. On return from DM_DEV_STATUS and other ioctls, the flag DM_DEFERRED_REMOVE is set if the device is scheduled to be removed on closure. A device that is scheduled to be deleted can be revived using the message "@cancel_deferred_remove". This message clears the DMF_DEFERRED_REMOVE flag so that the device won't be deleted on close. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Signed-off-by: Mike Snitzer --- drivers/md/dm.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/md/dm.h') diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 1d1ad7b7e527..c57ba550f69e 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -128,6 +128,16 @@ int dm_deleting_md(struct mapped_device *md); */ int dm_suspended_md(struct mapped_device *md); +/* + * Test if the device is scheduled for deferred remove. + */ +int dm_test_deferred_remove_flag(struct mapped_device *md); + +/* + * Try to remove devices marked for deferred removal. + */ +void dm_deferred_remove(void); + /* * The device-mapper can be driven through one of two interfaces; * ioctl or filesystem, depending which patch you have applied. @@ -158,7 +168,8 @@ void dm_stripe_exit(void); 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); +int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred); +int dm_cancel_deferred_remove(struct mapped_device *md); int dm_request_based(struct mapped_device *md); sector_t dm_get_size(struct mapped_device *md); struct dm_stats *dm_get_stats(struct mapped_device *md); -- cgit v1.2.3