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, 17 insertions, 0 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 6b49f14eac8c..cf02f5530713 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -175,6 +175,11 @@ static int nilfs_writepages(struct address_space *mapping,
 	struct inode *inode = mapping->host;
 	int err = 0;
 
+	if (inode->i_sb->s_flags & MS_RDONLY) {
+		nilfs_clear_dirty_pages(mapping, false);
+		return -EROFS;
+	}
+
 	if (wbc->sync_mode == WB_SYNC_ALL)
 		err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 						    wbc->range_start,
@@ -187,6 +192,18 @@ static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 	struct inode *inode = page->mapping->host;
 	int err;
 
+	if (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);