Merge branch 'akpm' (incoming from Andrew)

Merge third batch of fixes from Andrew Morton:
 "Most of the rest.  I still have two large patchsets against AIO and
  IPC, but they're a bit stuck behind other trees and I'm about to
  vanish for six days.

   - random fixlets
   - inotify
   - more of the MM queue
   - show_stack() cleanups
   - DMI update
   - kthread/workqueue things
   - compat cleanups
   - epoll udpates
   - binfmt updates
   - nilfs2
   - hfs
   - hfsplus
   - ptrace
   - kmod
   - coredump
   - kexec
   - rbtree
   - pids
   - pidns
   - pps
   - semaphore tweaks
   - some w1 patches
   - relay updates
   - core Kconfig changes
   - sysrq tweaks"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  Documentation/sysrq: fix inconstistent help message of sysrq key
  ethernet/emac/sysrq: fix inconstistent help message of sysrq key
  sparc/sysrq: fix inconstistent help message of sysrq key
  powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
  ARM/etm/sysrq: fix inconstistent help message of sysrq key
  power/sysrq: fix inconstistent help message of sysrq key
  kgdb/sysrq: fix inconstistent help message of sysrq key
  lib/decompress.c: fix initconst
  notifier-error-inject: fix module names in Kconfig
  kernel/sys.c: make prctl(PR_SET_MM) generally available
  UAPI: remove empty Kbuild files
  menuconfig: print more info for symbol without prompts
  init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
  kconfig menu: move Virtualization drivers near other virtualization options
  Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
  relay: use macro PAGE_ALIGN instead of FIX_SIZE
  kernel/relay.c: move FIX_SIZE macro into relay.c
  kernel/relay.c: remove unused function argument actor
  drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
  drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
  ...

1 files changed, 52 insertions, 18 deletions

diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index 07f76db04ec7..0ba679866e50 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -370,7 +370,12 @@ repeat:
 	goto repeat;
 }
 
-void nilfs_clear_dirty_pages(struct address_space *mapping)
+/**
+ * nilfs_clear_dirty_pages - discard dirty pages in address space
+ * @mapping: address space with dirty pages for discarding
+ * @silent: suppress [true] or print [false] warning messages
+ */
+void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent)
 {
 	struct pagevec pvec;
 	unsigned int i;
@@ -382,25 +387,9 @@ void nilfs_clear_dirty_pages(struct address_space *mapping)
 				  PAGEVEC_SIZE)) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
-			struct buffer_head *bh, *head;
 
 			lock_page(page);
-			ClearPageUptodate(page);
-			ClearPageMappedToDisk(page);
-			bh = head = page_buffers(page);
-			do {
-				lock_buffer(bh);
-				clear_buffer_dirty(bh);
-				clear_buffer_nilfs_volatile(bh);
-				clear_buffer_nilfs_checked(bh);
-				clear_buffer_nilfs_redirected(bh);
-				clear_buffer_uptodate(bh);
-				clear_buffer_mapped(bh);
-				unlock_buffer(bh);
-				bh = bh->b_this_page;
-			} while (bh != head);
-
-			__nilfs_clear_page_dirty(page);
+			nilfs_clear_dirty_page(page, silent);
 			unlock_page(page);
 		}
 		pagevec_release(&pvec);
@@ -408,6 +397,51 @@ void nilfs_clear_dirty_pages(struct address_space *mapping)
 	}
 }
 
+/**
+ * nilfs_clear_dirty_page - discard dirty page
+ * @page: dirty page that will be discarded
+ * @silent: suppress [true] or print [false] warning messages
+ */
+void nilfs_clear_dirty_page(struct page *page, bool silent)
+{
+	struct inode *inode = page->mapping->host;
+	struct super_block *sb = inode->i_sb;
+
+	BUG_ON(!PageLocked(page));
+
+	if (!silent) {
+		nilfs_warning(sb, __func__,
+				"discard page: offset %lld, ino %lu",
+				page_offset(page), inode->i_ino);
+	}
+
+	ClearPageUptodate(page);
+	ClearPageMappedToDisk(page);
+
+	if (page_has_buffers(page)) {
+		struct buffer_head *bh, *head;
+
+		bh = head = page_buffers(page);
+		do {
+			lock_buffer(bh);
+			if (!silent) {
+				nilfs_warning(sb, __func__,
+					"discard block %llu, size %zu",
+					(u64)bh->b_blocknr, bh->b_size);
+			}
+			clear_buffer_dirty(bh);
+			clear_buffer_nilfs_volatile(bh);
+			clear_buffer_nilfs_checked(bh);
+			clear_buffer_nilfs_redirected(bh);
+			clear_buffer_uptodate(bh);
+			clear_buffer_mapped(bh);
+			unlock_buffer(bh);
+		} while (bh = bh->b_this_page, bh != head);
+	}
+
+	__nilfs_clear_page_dirty(page);
+}
+
 unsigned nilfs_page_count_clean_buffers(struct page *page,
 					unsigned from, unsigned to)
 {