Messages in this thread | | | From | Ross Zwisler <> | Subject | [PATCH v3 0/3] Fix DM DAX handling | Date | Tue, 26 Jun 2018 11:59:29 -0600 |
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This series fixes a few issues that I found with DM's handling of DAX devices. Here are some of the issues I found:
* We can create a dm-stripe or dm-linear device which is made up of an fsdax PMEM namespace and a raw PMEM namespace but which can hold a filesystem mounted with the -o dax mount option. DAX operations to the raw PMEM namespace part lack struct page and can fail in interesting/unexpected ways when doing things like fork(), examining memory with gdb, etc.
* We can create a dm-stripe or dm-linear device which is made up of an fsdax PMEM namespace and a BRD ramdisk which can hold a filesystem mounted with the -o dax mount option. All I/O to this filesystem will fail.
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Changes since v2: * Only set QUEUE_FLAG_DAX for fsdax mode PMEM namespaces. (Mike) * Check for QUEUE_FLAG_DAX in __bdev_dax_supported(). (Mike) * Get rid of DM_TYPE_DAX_BIO_BASED reworks. (Mike) * Dropped the first 2 prep patches of v2 since they were merged for v4.18-rc1. (Thanks, Darrick!)
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Mike, can you take this series through your tree?
Personally I think this should be treated as a bug fix and merged in the v4.18-rc* series.
Ross Zwisler (3): pmem: only set QUEUE_FLAG_DAX for fsdax mode dax: bdev_dax_supported() check for QUEUE_FLAG_DAX dm: prevent DAX mounts if not supported
drivers/dax/super.c | 8 ++++++++ drivers/md/dm-ioctl.c | 5 +++++ drivers/md/dm-table.c | 7 +++---- drivers/md/dm.c | 3 +-- drivers/nvdimm/pmem.c | 3 ++- include/linux/device-mapper.h | 5 +++++ 6 files changed, 24 insertions(+), 7 deletions(-)
-- 2.14.4
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