> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > On Tue, Sep 07, 2010 at 12:33:31PM -0700, David Cross wrote: > > This patch adds the mpage_cleardirty function to the cachefiles implementation in the kernel. > > The purpose behind this patch is to allow for file based DMA through an external DMA engine > > without the data ever going through the process. The procedure for the usage of this function > > is as follows: > > 1) User space allocates and maps a file > > 2) external DMA device transfers the data to non-volatile storage directly without it going through > > the processor > > 3) the "dirty" pages must be cleared and invalidated as they do not contain correct information. > > > > I believe that David is the correct maintainer and am hoping that he is willing to ACK this change. Please let me know > > if there are any issues or concerns with this patch or if I should be > > asking a different maintainer to ack. > > Thanks, > > David > > > > Signed-off-by: David Cross <david.cross@xxxxxxxxxxx> > > > > diff -uprN -X linux-next-vanilla/Documentation/dontdiff linux-next-vanilla/fs/mpage.c linux-next-incl-sdk/fs/mpage.c > > --- linux-next-vanilla/fs/mpage.c 2010-08-31 19:32:51.000000000 -0700 > > +++ linux-next-incl-sdk/fs/mpage.c 2010-09-07 11:52:39.000000000 -0700 > > @@ -716,3 +716,50 @@ int mpage_writepage(struct page *page, g > > return ret; > > } > > EXPORT_SYMBOL(mpage_writepage); > > + > > +int mpage_cleardirty(struct address_space *mapping, int num_pages) > > +{ > > + int ret = 0; > > + int nr_pages; > > + struct pagevec pvec; > > + pgoff_t index = 0; > > + pgoff_t end; > > + > > + pagevec_init(&pvec, 0); > > + index = mapping->writeback_index; > > + end = index + num_pages; > > + > > + while ((index <= end) && > > + (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, > > + PAGECACHE_TAG_DIRTY, min(end - index, > > + (pgoff_t)PAGEVEC_SIZE-1) + 1))) { > > + unsigned i; > > + > > + for (i = 0; i < nr_pages; i++) { > > + struct page *page = pvec.pages[i]; > > + > > + lock_page(page); > > + ret = clear_page_dirty_for_io(page); > > + if (page_has_private(page)) > > + do_invalidatepage(page, 0); > > + > > + cancel_dirty_page(page, PAGE_CACHE_SIZE); > > + > > + remove_from_page_cache(page); > > + ClearPageMappedToDisk(page); > > + page_cache_release(page); /* pagecache ref */ > > + unlock_page(page); > > + > > + if (!ret) { > > + printk(KERN_INFO "mpage_cleardirty: " > > + "clear_page_dirty_for_io returned %d\n", ret); > > + return ret; > > + } > > + } > > + pagevec_release(&pvec); > > + cond_resched(); > > + } > > + > > + return ret; > > +} > > +EXPORT_SYMBOL(mpage_cleardirty); > EXPORT_SYMBOL_GPL()? Sure, but do I need to submit a new patch for this as well? thanks, david --------------------------------------------------------------- This message and any attachments may contain Cypress (or its subsidiaries) confidential information. If it has been received in error, please advise the sender and immediately delete this message. --------------------------------------------------------------- -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs
