3 commits

Author	SHA1	Message	Date
Joe Thornber	989f26f5ad	dm era: check for a non-NULL metadata object before closing it ... era_ctr() may call era_destroy() before era->md is initialized so era_destory() must only close the metadata object if it is not NULL. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Naohiro Aota <naota@elisp.net> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.15+	2014-06-03 13:44:08 -04:00
Joe Thornber	5a32083d03	dm: take care to copy the space map roots before locking the superblock ... In theory copying the space map root can fail, but in practice it never does because we're careful to check what size buffer is needed. But make certain we're able to copy the space map roots before locking the superblock. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # drop dm-era and dm-cache changes as needed	2014-03-27 16:56:23 -04:00
Joe Thornber	eec40579d8	dm: add era target ... dm-era is a target that behaves similar to the linear target. In addition it keeps track of which blocks were written within a user defined period of time called an 'era'. Each era target instance maintains the current era as a monotonically increasing 32-bit counter. Use cases include tracking changed blocks for backup software, and partially invalidating the contents of a cache to restore cache coherency after rolling back a vendor snapshot. dm-era is primarily expected to be paired with the dm-cache target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>	2014-03-27 16:56:23 -04:00