linux-toradex.git/drivers/md/persistent-data/dm-block-manager.c, branch v3.7

dm persistent data: introduce dm_bm_set_read_only

2012-07-27T14:08:15+00:00

Introduce dm_bm_set_read_only to switch the block manager into a
read-only mode.  To be used when dm-thin degrades due to io errors on
the metadata device.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm persistent data: stop using dm_bm_unlock_move when shadowing blocks in tm

2012-07-27T14:08:09+00:00

Stop using dm_bm_unlock_move when shadowing blocks in the transaction
manager as an optimisation and remove the function as it is then no
longer used.

Some code, such as the space maps, keeps using on-disk data structures
from the previous transaction.  It can do this because blocks won't
be reallocated until the subsequent transaction.  Using
dm_bm_unlock_move to copy blocks sounds like a win, but it forces a
synchronous read should the old block be accessed.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm persistent data: tidy transaction manager creation fns

2012-07-27T14:08:09+00:00

Tidy the transaction manager creation functions.

They no longer lock the superblock.  Superblock locking is pulled out to
the caller.

Also export dm_bm_write_lock_zero.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm persistent data: create new dm_block_manager struct

2012-07-27T14:08:08+00:00

This patch introduces a separate struct for the block_manager.
It also uses IS_ERR to check the return value of dm_bufio_client_create
instead of testing incorrectly for NULL.

Prior to this patch a struct dm_block_manager was really an alias for
a struct dm_bufio_client.  We want to add some functionality to the
block manager that will require extra fields, so this one to one
mapping is no longer valid.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm persistent data: always unlock superblock in dm_bm_flush_and_unlock

2012-07-27T14:08:06+00:00

Unlock the superblock even if initial dm_bufio_write_dirty_buffers fails.

Also, remove redundant flush calls.  dm_bm_flush_and_unlock's calls to
dm_bufio_write_dirty_buffers already result in dm_bufio_issue_flush
being called.

This avoids warnings about unflushed dirty buffers from bufio.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm: add persistent data library

2011-10-31T20:19:11+00:00

The persistent-data library offers a re-usable framework for the storage
and management of on-disk metadata in device-mapper targets.

It's used by the thin-provisioning target in the next patch and in an
upcoming hierarchical storage target.

For further information, please read
Documentation/device-mapper/persistent-data.txt

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon