Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - a few misc things

 - ocfs2 updates

 - the v9fs maintainers have been missing for a long time. I've taken
   over v9fs patch slinging.

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (116 commits)
  mm,oom_reaper: check for MMF_OOM_SKIP before complaining
  mm/ksm: fix interaction with THP
  mm/memblock.c: cast constant ULLONG_MAX to phys_addr_t
  headers: untangle kmemleak.h from mm.h
  include/linux/mmdebug.h: make VM_WARN* non-rvals
  mm/page_isolation.c: make start_isolate_page_range() fail if already isolated
  mm: change return type to vm_fault_t
  mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes
  mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory
  kernel/fork.c: detect early free of a live mm
  mm: make counting of list_lru_one::nr_items lockless
  mm/swap_state.c: make bool enable_vma_readahead and swap_vma_readahead() static
  block_invalidatepage(): only release page if the full page was invalidated
  mm: kernel-doc: add missing parameter descriptions
  mm/swap.c: remove @cold parameter description for release_pages()
  mm/nommu: remove description of alloc_vm_area
  zram: drop max_zpage_size and use zs_huge_class_size()
  zsmalloc: introduce zs_huge_class_size()
  mm: fix races between swapoff and flush dcache
  fs/direct-io.c: minor cleanups in do_blockdev_direct_IO
  ...

3 files changed, 30 insertions, 5 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 8fb89ddc6cc7..e622f0f10502 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -292,6 +292,10 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 #ifdef CONFIG_9P_FSCACHE
 			kfree(v9ses->cachetag);
 			v9ses->cachetag = match_strdup(&args[0]);
+			if (!v9ses->cachetag) {
+				ret = -ENOMEM;
+				goto free_and_return;
+			}
 #endif
 			break;
 		case Opt_cache:
@@ -471,6 +475,9 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	return fid;
 
 err_clnt:
+#ifdef CONFIG_9P_FSCACHE
+	kfree(v9ses->cachetag);
+#endif
 	p9_client_destroy(v9ses->clnt);
 err_names:
 	kfree(v9ses->uname);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index bdabb2765d1b..9ee534159cc6 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -579,6 +579,24 @@ static int v9fs_at_to_dotl_flags(int flags)
 }
 
 /**
+ * v9fs_dec_count - helper functon to drop i_nlink.
+ *
+ * If a directory had nlink <= 2 (including . and ..), then we should not drop
+ * the link count, which indicates the underlying exported fs doesn't maintain
+ * nlink accurately. e.g.
+ * - overlayfs sets nlink to 1 for merged dir
+ * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
+ *   than EXT4_LINK_MAX (65000) links.
+ *
+ * @inode: inode whose nlink is being dropped
+ */
+static void v9fs_dec_count(struct inode *inode)
+{
+	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
+		drop_nlink(inode);
+}
+
+/**
  * v9fs_remove - helper function to remove files and directories
  * @dir: directory inode that is being deleted
  * @dentry:  dentry that is being deleted
@@ -621,9 +639,9 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 		 */
 		if (flags & AT_REMOVEDIR) {
 			clear_nlink(inode);
-			drop_nlink(dir);
+			v9fs_dec_count(dir);
 		} else
-			drop_nlink(inode);
+			v9fs_dec_count(inode);
 
 		v9fs_invalidate_inode_attr(inode);
 		v9fs_invalidate_inode_attr(dir);
@@ -1024,12 +1042,12 @@ clunk_newdir:
 			if (S_ISDIR(new_inode->i_mode))
 				clear_nlink(new_inode);
 			else
-				drop_nlink(new_inode);
+				v9fs_dec_count(new_inode);
 		}
 		if (S_ISDIR(old_inode->i_mode)) {
 			if (!new_inode)
 				inc_nlink(new_dir);
-			drop_nlink(old_dir);
+			v9fs_dec_count(old_dir);
 		}
 		v9fs_invalidate_inode_attr(old_inode);
 		v9fs_invalidate_inode_attr(old_dir);
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index af03c2a901eb..48ce50484e80 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -94,7 +94,7 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 	if (v9ses->cache)
 		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE;
 
-	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME;
+	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)
 		sb->s_flags |= SB_SYNCHRONOUS;