Re: [PATCH] btrfs: Convert zlib_decompress_bio() to use kmap_local_page()

[David Sterba]

On Sat, Jun 18, 2022 at 11:19:01AM +0200, Fabio M. De Francesco wrote:
> The use of kmap() is being deprecated in favor of kmap_local_page(). With
> kmap_local_page(), the mapping is per thread, CPU local and not globally
> visible.
> 
> Therefore, use kmap_local_page() / kunmap_local() in zlib_decompress_bio()
> because in this function the mappings are per thread and are not visible
> in other contexts.
> 
> Tested with xfstests on QEMU + KVM 32-bits VM with 4GB of RAM and
> HIGHMEM64G enabled. This patch passes 26/26 tests of group "compress".
> 
> Suggested-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>

Added to the kmap patches, thanks.