kernel_samsung_sm7125

jenna

History

Joe Thornber a9d45396f5 dm transaction manager: fix corruption due to non-atomic transaction commit The persistent-data library used by dm-thin, dm-cache, etc is transactional. If anything goes wrong, such as an io error when writing new metadata or a power failure, then we roll back to the last transaction. Atomicity when committing a transaction is achieved by: a) Never overwriting data from the previous transaction. b) Writing the superblock last, after all other metadata has hit the disk. This commit and the following commit ("dm: take care to copy the space map roots before locking the superblock") fix a bug associated with (b). When committing it was possible for the superblock to still be written in spite of an io error occurring during the preceeding metadata flush. With these commits we're careful not to take the write lock out on the superblock until after the metadata flush has completed. Change the transaction manager's semantics for dm_tm_commit() to assume all data has been flushed _before_ the single superblock that is passed in. As a prerequisite, split the block manager's block unlocking and flushing by simplifying dm_bm_flush_and_unlock() to dm_bm_flush(). Now the unlocking must be done separately. This issue was discovered by forcing io errors at the crucial time using dm-flakey. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org		11 years ago
..
Kconfig	dm: fix Kconfig indentation	11 years ago
Makefile	…
dm-array.c	…
dm-array.h	…
dm-bitset.c	dm bitset: only flush the current word if it has been dirtied	11 years ago
dm-bitset.h	dm bitset: only flush the current word if it has been dirtied	11 years ago
dm-block-manager.c	dm transaction manager: fix corruption due to non-atomic transaction commit	11 years ago
dm-block-manager.h	dm transaction manager: fix corruption due to non-atomic transaction commit	11 years ago
dm-btree-internal.h	…
dm-btree-remove.c	…
dm-btree-spine.c	…
dm-btree.c	dm btree: add dm_btree_find_lowest_key	11 years ago
dm-btree.h	dm btree: add dm_btree_find_lowest_key	11 years ago
dm-persistent-data-internal.h	…
dm-space-map-common.c	…
dm-space-map-common.h	…
dm-space-map-disk.c	…
dm-space-map-disk.h	…
dm-space-map-metadata.c	dm space map metadata: fix refcount decrement below 0 which caused corruption	11 years ago
dm-space-map-metadata.h	dm thin: allow metadata space larger than supported to go unused	11 years ago
dm-space-map.h	…
dm-transaction-manager.c	dm transaction manager: fix corruption due to non-atomic transaction commit	11 years ago
dm-transaction-manager.h	dm transaction manager: fix corruption due to non-atomic transaction commit	11 years ago