| tag | 9742af4769c556de83b9c93bf70bf76e396ae7d1 | |
|---|---|---|
| tagger | Dan Williams <dan.j.williams@intel.com> | Sun Sep 20 11:23:06 2020 -0700 |
| object | d4c5da5049ac27c6ef8f6f98548c3a1ade352d25 |
libnvdimm fixes for 5.9-rc6 - Fix an original bug in device-mapper table reference counting when interrogating dax capability in the component device. This bug was hidden by the following bug. - Fix device-mapper to use the proper helper (dax_supported() instead of the leaf helper generic_fsdax_supported()) to determine dax operation of a stacked block device configuration. The original implementation is only valid for one level of dax-capable block device stacking. This bug was discovered while fixing the below regression. - Fix an infinite recursion regression introduced by broken attempts to quiet the generic_fsdax_supported() path and make it bail out before logging "dax capability not found" errors.
| commit | d4c5da5049ac27c6ef8f6f98548c3a1ade352d25 | [log] [tgz] |
|---|---|---|
| author | Adrian Huang <ahuang12@lenovo.com> | Thu Sep 17 19:15:49 2020 +0800 |
| committer | Dan Williams <dan.j.williams@intel.com> | Sun Sep 20 08:57:36 2020 -0700 |
| tree | cc167f186cdc547b3f372c117692a186fe22b016 | |
| parent | e2ec5128254518cae320d5dc631b71b94160f663 [diff] |
dax: Fix stack overflow when mounting fsdax pmem device
When mounting fsdax pmem device, commit 6180bb446ab6 ("dax: fix
detection of dax support for non-persistent memory block devices")
introduces the stack overflow [1][2]. Here is the call path for
mounting ext4 file system:
ext4_fill_super
bdev_dax_supported
__bdev_dax_supported
dax_supported
generic_fsdax_supported
__generic_fsdax_supported
bdev_dax_supported
The call path leads to the infinite calling loop, so we cannot
call bdev_dax_supported() in __generic_fsdax_supported(). The sanity
checking of the variable 'dax_dev' is moved prior to the two
bdev_dax_pgoff() checks [3][4].
[1] https://lore.kernel.org/linux-nvdimm/1420999447.1004543.1600055488770.JavaMail.zimbra@redhat.com/
[2] https://lore.kernel.org/linux-nvdimm/alpine.LRH.2.02.2009141131220.30651@file01.intranet.prod.int.rdu2.redhat.com/
[3] https://lore.kernel.org/linux-nvdimm/CA+RJvhxBHriCuJhm-D8NvJRe3h2MLM+ZMFgjeJjrRPerMRLvdg@mail.gmail.com/
[4] https://lore.kernel.org/linux-nvdimm/20200903160608.GU878166@iweiny-DESK2.sc.intel.com/
Fixes: 6180bb446ab6 ("dax: fix detection of dax support for non-persistent memory block devices")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: Coly Li <colyli@suse.de>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: John Pittman <jpittman@redhat.com>
Link: https://lore.kernel.org/r/20200917111549.6367-1-adrianhuang0701@gmail.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>