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, 15 insertions, 4 deletions

diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index f9897d09c693..c4dcd1db57ee 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -375,14 +375,25 @@ int nilfs_mdt_fetch_dirty(struct inode *inode)
 static int
 nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
 {
-	struct inode *inode;
+	struct inode *inode = page->mapping->host;
 	struct super_block *sb;
 	int err = 0;
 
+	if (inode && (inode->i_sb->s_flags & MS_RDONLY)) {
+		/*
+		 * It means that filesystem was remounted in read-only
+		 * mode because of error or metadata corruption. But we
+		 * have dirty pages that try to be flushed in background.
+		 * So, here we simply discard this dirty page.
+		 */
+		nilfs_clear_dirty_page(page, false);
+		unlock_page(page);
+		return -EROFS;
+	}
+
 	redirty_page_for_writepage(wbc, page);
 	unlock_page(page);
 
-	inode = page->mapping->host;
 	if (!inode)
 		return 0;
 
@@ -561,10 +572,10 @@ void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
 	if (mi->mi_palloc_cache)
 		nilfs_palloc_clear_cache(inode);
 
-	nilfs_clear_dirty_pages(inode->i_mapping);
+	nilfs_clear_dirty_pages(inode->i_mapping, true);
 	nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data);
 
-	nilfs_clear_dirty_pages(&ii->i_btnode_cache);
+	nilfs_clear_dirty_pages(&ii->i_btnode_cache, true);
 	nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes);
 
 	nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);