mm/fs: add hooks to support cleancache

fs/buffer.c

@@ -41,6 +41,7 @@
 #include <linux/bitops.h>
 #include <linux/mpage.h>
 #include <linux/bit_spinlock.h>
+#include <linux/cleancache.h>
 
 static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
 
@@ -276,6 +277,10 @@ void invalidate_bdev(struct block_device *bdev)
 
 	invalidate_bh_lrus();
 	invalidate_mapping_pages(mapping, 0, -1);
+    /* 99% of the time, we don't need to flush the cleancache on the bdev.
+    * But, for the strange corners, lets be cautious
+    */
+    cleancache_flush_inode(mapping);	
 }
 EXPORT_SYMBOL(invalidate_bdev);
 

fs/mpage.c

@@ -26,6 +26,7 @@
 #include <linux/writeback.h>
 #include <linux/backing-dev.h>
 #include <linux/pagevec.h>
+#include <linux/cleancache.h>
 
 /*
  * I/O completion handler for multipage BIOs.
@@ -284,6 +285,12 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
 	} else if (fully_mapped) {
 		SetPageMappedToDisk(page);
 	}
+	
+    if (fully_mapped && blocks_per_page == 1 && !PageUptodate(page) &&
+       cleancache_get_page(page) == 0) {
+           SetPageUptodate(page);
+           goto confused;
+    }
 
 	/*
 	 * This page will go to BIO.  Do we need to send this BIO off first?

fs/super.c

@@ -38,6 +38,7 @@
 #include <linux/mutex.h>
 #include <linux/file.h>
 #include <asm/uaccess.h>
+#include <linux/cleancache.h>
 #include "internal.h"
 
 
@@ -104,6 +105,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
 		s->s_qcop = sb_quotactl_ops;
 		s->s_op = &default_op;
 		s->s_time_gran = 1000000000;
+		s->cleancache_poolid = -1;
 	}
 out:
 	return s;
@@ -219,6 +221,7 @@ void deactivate_locked_super(struct super_block *s)
 		s->s_count -= S_BIAS-1;
 		spin_unlock(&sb_lock);
 		vfs_dq_off(s, 0);
+		cleancache_flush_fs(s);
 		fs->kill_sb(s);
 		put_filesystem(fs);
 		put_super(s);

mm/filemap.c

@@ -34,6 +34,7 @@
 #include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
 #include <linux/memcontrol.h>
 #include <linux/mm_inline.h> /* for page_is_file_cache() */
+#include <linux/cleancache.h>
 #include "internal.h"
 
 /*
@@ -119,6 +120,16 @@ void __remove_from_page_cache(struct page *page)
 {
 	struct address_space *mapping = page->mapping;
 
+   /*
+    * if we're uptodate, flush out into the cleancache, otherwise
+    * invalidate any existing cleancache entries.  We can't leave
+    * stale data around in the cleancache once our page is gone
+    */
+   if (PageUptodate(page) && PageMappedToDisk(page))
+       cleancache_put_page(page);
+   else
+       cleancache_flush_page(mapping, page);
+
 	radix_tree_delete(&mapping->page_tree, page->index);
 	page->mapping = NULL;
 	mapping->nrpages--;

mm/truncate.c

@@ -18,6 +18,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/buffer_head.h>	/* grr. try_to_release_page,
 				   do_invalidatepage */
+#include <linux/cleancache.h>
 #include "internal.h"
 
 
@@ -50,6 +51,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
 	zero_user_segment(page, partial, PAGE_CACHE_SIZE);
+	cleancache_flush_page(page->mapping, page);
 	if (page_has_private(page))
 		do_invalidatepage(page, partial);
 }
@@ -213,7 +215,8 @@ void truncate_inode_pages_range(struct address_space *mapping,
 	struct pagevec pvec;
 	pgoff_t next;
 	int i;
-
+	
+    cleancache_flush_inode(mapping);
 	if (mapping->nrpages == 0)
 		return;
 
@@ -287,6 +290,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 		}
 		pagevec_release(&pvec);
 	}
+	cleancache_flush_inode(mapping);
 }
 EXPORT_SYMBOL(truncate_inode_pages_range);
 
@@ -423,6 +427,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 	int did_range_unmap = 0;
 	int wrapped = 0;
 
+    cleancache_flush_inode(mapping);
 	pagevec_init(&pvec, 0);
 	next = start;
 	while (next <= end && !wrapped &&
@@ -479,6 +484,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 		pagevec_release(&pvec);
 		cond_resched();
 	}
+	cleancache_flush_inode(mapping);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);