]> git.baikalelectronics.ru Git - kernel.git/commit
ext2: remove support for DAX PMD faults
authorRoss Zwisler <ross.zwisler@linux.intel.com>
Tue, 8 Nov 2016 00:31:33 +0000 (11:31 +1100)
committerDave Chinner <david@fromorbit.com>
Tue, 8 Nov 2016 00:31:33 +0000 (11:31 +1100)
commit45050261cb14b375c4a27eb3faea5b2d436cdb32
treeeb5a38d99ac247345642582ec726253ab5dee3ae
parent615a157c157fb309ad8c14c1c25531a87d388b70
ext2: remove support for DAX PMD faults

DAX PMD support was added via the following commit:

commit fad2f52b95ec ("ext2: huge page fault support")

I believe this path to be untested as ext2 doesn't reliably provide block
allocations that are aligned to 2MiB.  In my testing I've been unable to
get ext2 to actually fault in a PMD.  It always fails with a "pfn
unaligned" message because the sector returned by ext2_get_block() isn't
aligned.

I've tried various settings for the "stride" and "stripe_width" extended
options to mkfs.ext2, without any luck.

Since we can't reliably get PMDs, remove support so that we don't have an
untested code path that we may someday traverse when we happen to get an
aligned block allocation.  This should also make 4k DAX faults in ext2 a
bit faster since they will no longer have to call the PMD fault handler
only to get a response of VM_FAULT_FALLBACK.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
fs/ext2/file.c