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 <vgoyal@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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:[<ffffffff81593659>] [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20
Call Trace:
[<ffffffff81599bae>] dm_bm_block_size+0xe/0x10
[<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0
[<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0
[<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160
[<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0
[<ffffffff815aa010>] pool_ctr+0x3f0/0x900
[<ffffffff8158d565>] dm_table_add_target+0x195/0x450
[<ffffffff815904c4>] table_load+0xe4/0x330
[<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0
[<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20
[<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560
[<ffffffff8116aa51>] sys_ioctl+0x91/0xa0
[<ffffffff81869f52>] 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 <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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 <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mike Snitzer
Stephen Rothwell
Joe Thornber