X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=mm%2Fshmem.c;h=51b3d6ccddab75ba33b7fded5ffaf75700770ccd;hb=3ba5619f06300cd0944150901ed20de87483ad8c;hp=404e53bb212764f8a6ab7f5bf688c54d4d4c9d06;hpb=39655164405940d4818224a085e35420e2f97aed;p=linux-2.6-omap-h63xx.git

diff --git a/mm/shmem.c b/mm/shmem.c
index 404e53bb212..51b3d6ccdda 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -915,6 +915,21 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
 	struct inode *inode;
 
 	BUG_ON(!PageLocked(page));
+	/*
+	 * shmem_backing_dev_info's capabilities prevent regular writeback or
+	 * sync from ever calling shmem_writepage; but a stacking filesystem
+	 * may use the ->writepage of its underlying filesystem, in which case
+	 * we want to do nothing when that underlying filesystem is tmpfs
+	 * (writing out to swap is useful as a response to memory pressure, but
+	 * of no use to stabilize the data) - just redirty the page, unlock it
+	 * and claim success in this case.  AOP_WRITEPAGE_ACTIVATE, and the
+	 * page_mapped check below, must be avoided unless we're in reclaim.
+	 */
+	if (!wbc->for_reclaim) {
+		set_page_dirty(page);
+		unlock_page(page);
+		return 0;
+	}
 	BUG_ON(page_mapped(page));
 
 	mapping = page->mapping;
@@ -1057,7 +1072,7 @@ shmem_alloc_page(gfp_t gfp, struct shmem_inode_info *info,
 	pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
 	pvma.vm_pgoff = idx;
 	pvma.vm_end = PAGE_SIZE;
-	page = alloc_page_vma(gfp | __GFP_ZERO, &pvma, 0);
+	page = alloc_page_vma(gfp, &pvma, 0);
 	mpol_free(pvma.vm_policy);
 	return page;
 }
@@ -1078,7 +1093,7 @@ shmem_swapin(struct shmem_inode_info *info,swp_entry_t entry,unsigned long idx)
 static inline struct page *
 shmem_alloc_page(gfp_t gfp,struct shmem_inode_info *info, unsigned long idx)
 {
-	return alloc_page(gfp | __GFP_ZERO);
+	return alloc_page(gfp);
 }
 #endif
 
@@ -1291,6 +1306,7 @@ repeat:
 
 		info->alloced++;
 		spin_unlock(&info->lock);
+		clear_highpage(filepage);
 		flush_dcache_page(filepage);
 		SetPageUptodate(filepage);
 	}