linux-toradex.git/drivers/md/persistent-data, branch v3.6-rc1

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mapping is no longer valid.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: only commit space map if index changed

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

Introduce bitmap_index_changed to track whether or not the index changed
then only commit a space map if it did.

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 persistent data: remove debug space map checker

2012-07-27T14:07:58+00:00

Remove debug space map checker from dm persistent data.

The space map checker is a wrapper for other space maps that double
checks the reference counts are correct.  It holds all these reference
counts in memory rather than on disk, so uses a lot of memory and is
thus restricted to small pools.

As yet, this checker hasn't found any issues, but has caused a few of
its own due to people turning it on by default with larger pools.

Removing.

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

dm persistent data: fix allocation failure in space map checker init

2012-07-03T11:55:37+00:00

If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and memory is fragmented and a
sufficiently-large metadata device is used in a thin pool then the space
map checker will fail to allocate the memory it requires.

Switch from kmalloc to vmalloc to allow larger virtually contiguous
allocations for the space map checker's internal count arrays.

Reported-by: Vivek Goyal 
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Alasdair G Kergon

dm persistent data: handle space map checker creation failure

2012-07-03T11:55:35+00:00

If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create()
fails, dm_tm_create_internal() would still return success even though it
cleaned up all resources it was supposed to have created.  This will
lead to a kernel crash:

general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
...
RIP: 0010:[]  [] dm_bufio_get_block_size+0x9/0x20
Call Trace:
  [] dm_bm_block_size+0xe/0x10
  [] sm_ll_init+0x78/0xd0
  [] sm_ll_new_disk+0x16/0xa0
  [] dm_sm_disk_create+0xfe/0x160
  [] dm_pool_metadata_open+0x16e/0x6a0
  [] pool_ctr+0x3f0/0x900
  [] dm_table_add_target+0x195/0x450
  [] table_load+0xe4/0x330
  [] ctl_ioctl+0x15a/0x2c0
  [] dm_ctl_ioctl+0x13/0x20
  [] do_vfs_ioctl+0x98/0x560
  [] sys_ioctl+0x91/0xa0
  [] system_call_fastpath+0x16/0x1b

Fix the space map checker code to return an appropriate ERR_PTR and have
dm_sm_disk_create() and dm_tm_create_internal() check for it with
IS_ERR.

Reported-by: Vivek Goyal 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon

dm persistent data: fix shadow_info_leak on dm_tm_destroy

2012-07-03T11:55:33+00:00

Cleanup the shadow table before destroying the transaction manager.

Reference: leak was identified with kmemleak when running
test_discard_random_sectors in the thinp-test-suite.

Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon