Two fixes for 4.4-rc1's DM ioctl changes that introduced the potential
for infinite recursion on ioctl (with DM multipath).
And four stable fixes:
- A DM thin-provisioning fix to restore 'error_if_no_space' setting when
a thin-pool is made writable again (after having been out of space).
- A DM thin-provisioning fix to properly advertise discard support for
thin volumes that are stacked on a thin-pool whose underlying data
device doesn't support discards.
- A DM ioctl fix to allow ctrl-c to break out of an ioctl retry loop
when DM multipath is configured to 'queue_if_no_path'.
- A DM crypt fix for a possible hang on dm-crypt device removal.
dm thin: fix regression in advertised discard limits
When establishing a thin device's discard limits we cannot rely on the
underlying thin-pool device's discard capabilities (which are inherited
from the thin-pool's underlying data device) given that DM thin devices
must provide discard support even when the thin-pool's underlying data
device doesn't support discards.
Users were exposed to this thin device discard limits regression if
their thin-pool's underlying data device does _not_ support discards.
This regression caused all upper-layers that called the
blkdev_issue_discard() interface to not be able to issue discards to
thin devices (because discard_granularity was 0). This regression
wasn't caught earlier because the device-mapper-test-suite's extensive
'thin-provisioning' discard tests are only ever performed against
thin-pool's with data devices that support discards.
Fix is to have thin_io_hints() test the pool's 'discard_enabled' feature
rather than inferring whether or not a thin device's discard support
should be enabled by looking at the thin-pool's discard_granularity.
Fixes: 216076705 ("dm thin: disable discard support for thin devices if pool's is disabled")
Reported-by: Mike Gerber <mike@sprachgewalt.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.1+
1 file changed
