On Fri, Jan 06, 2012 at 03:01:09PM -0800, Linus Torvalds wrote: > On Thu, Jan 5, 2012 at 4:18 PM, Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote: > > > > In linux-next, fs/fs-writeback.c no longer #includes <linux/buffer_head.h>, > > which #included <linux/pagemap.h>, so add that latter header file to > > <linux/writeback.h> to fix the build error: > > > > fs/fs-writeback.c:510:11: error: 'PAGE_CACHE_SHIFT' undeclared (first use in this function) > > I would actually suggest: > > - move the whole MIN_WRITEBACK_PAGES #define from the header file to > fs/writeback.c Done. > (why expose such a random #define to outside users that > have nothing to do with it?) Yeah, there were some early patches that reference MIN_WRITEBACK_PAGES from other files, which are dropped later.. > - make sure that fs/fs-writeback.c has that pagemap.h #include. Done. (otherwise it won't compile) > There's no reason why <linux/writeback.h> should include filemap.h per > se, and there is no reason why it should expose some internal chunking > #define to anybody else. Good point. I'll queue this patch to writeback-for-next: Subject: writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c Date: Sat Jan 07 20:41:55 CST 2012 Fix compile error fs/fs-writeback.c:515:33: error: ‘PAGE_CACHE_SHIFT’ undeclared (first use in this function) Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxx> Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> --- fs/fs-writeback.c | 6 ++++++ include/linux/writeback.h | 5 ----- 2 files changed, 6 insertions(+), 5 deletions(-) --- next.orig/fs/fs-writeback.c 2012-01-07 21:01:34.552000061 +0800 +++ next/fs/fs-writeback.c 2012-01-07 21:22:45.504000051 +0800 @@ -20,6 +20,7 @@ #include <linux/sched.h> #include <linux/fs.h> #include <linux/mm.h> +#include <linux/pagemap.h> #include <linux/kthread.h> #include <linux/freezer.h> #include <linux/writeback.h> @@ -29,6 +30,11 @@ #include "internal.h" /* + * 4MB minimal write chunk size + */ +#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10)) + +/* * Passed into wb_writeback(), essentially a subset of writeback_control */ struct wb_writeback_work { --- next.orig/include/linux/writeback.h 2012-01-07 21:01:34.544000059 +0800 +++ next/include/linux/writeback.h 2012-01-07 21:13:09.008000026 +0800 @@ -25,11 +25,6 @@ DECLARE_PER_CPU(int, dirty_throttle_leak #define DIRTY_SCOPE 8 #define DIRTY_FULL_SCOPE (DIRTY_SCOPE / 2) -/* - * 4MB minimal write chunk size - */ -#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10)) - struct backing_dev_info; /* -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html