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See http://www.infradead.org/rpr.html X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-loop: dm-devel@redhat.com Cc: linux-arch@vger.kernel.org, linux-block@vger.kernel.org, Thomas Bogendoerfer , Mike Snitzer , Geoff Levand , linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, Dongsheng Yang , linux-kernel@vger.kernel.org, "James E.J. Bottomley" , dm-devel@redhat.com, Ilya Dryomov , Ira Weiny , ceph-devel@vger.kernel.org Subject: [dm-devel] [PATCH 01/18] mm: add a kunmap_local_dirty helper X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Add a helper that calls flush_kernel_dcache_page before unmapping the local mapping. flush_kernel_dcache_page is required for all pages potentially mapped into userspace that were written to using kmap*, so having a helper that does the right thing can be very convenient. Signed-off-by: Christoph Hellwig --- include/linux/highmem-internal.h | 7 +++++++ include/linux/highmem.h | 4 ++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h index 7902c7d8b55f..bd37706db147 100644 --- a/include/linux/highmem-internal.h +++ b/include/linux/highmem-internal.h @@ -224,4 +224,11 @@ do { \ __kunmap_local(__addr); \ } while (0) +#define kunmap_local_dirty(__page, __addr) \ +do { \ + if (!PageSlab(__page)) \ + flush_kernel_dcache_page(__page); \ + kunmap_local(__addr); \ +} while (0) + #endif diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 832b49b50c7b..65f548db4f2d 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -93,6 +93,10 @@ static inline void kmap_flush_unused(void); * On HIGHMEM enabled systems mapping a highmem page has the side effect of * disabling migration in order to keep the virtual address stable across * preemption. No caller of kmap_local_page() can rely on this side effect. + * + * If data is written to the returned kernel mapping, the callers needs to + * unmap the mapping using kunmap_local_dirty(), else kunmap_local() should + * be used. */ static inline void *kmap_local_page(struct page *page); -- 2.30.2 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel