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Coly Li authored
When calling __generic_fsdax_supported(), a dax-unsupported device may not have dax_dev as NULL, e.g. the dax related code block is not enabled by Kconfig. Therefore in __generic_fsdax_supported(), to check whether a device supports DAX or not, the following order of operations should be performed: - If dax_dev pointer is NULL, it means the device driver explicitly announce it doesn't support DAX. Then it is OK to directly return false from __generic_fsdax_supported(). - If dax_dev pointer is NOT NULL, it might be because the driver doesn't support DAX and not explicitly initialize related data structure. Then bdev_dax_supported() should be called for further check. If device driver desn't explicitly set its dax_dev pointer to NULL, this is not a bug. Calling bdev_dax_supported() makes sure they can be recognized as dax-unsupported eventually. Fixes: c2affe92 ("dax: do not print error message for non-persistent memory block device") Cc: Jan Kara <jack@suse.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Reviewed-and-tested-by:
Adrian Huang <ahuang12@lenovo.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Reviewed-by:
Mike Snitzer <snitzer@redhat.com> Reviewed-by:
Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by:
Coly Li <colyli@suse.de> Signed-off-by:
Vishal Verma <vishal.l.verma@intel.com> Link: https://lore.kernel.org/r/20200903161625.19524-1-colyli@suse.de
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