Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs pile 1 from Al Viro:
 "Unfortunately, this merge window it'll have a be a lot of small piles -
  my fault, actually, for not keeping #for-next in anything that would
  resemble a sane shape ;-/

  This pile: assorted fixes (the first 3 are -stable fodder, IMO) and
  cleanups + %pd/%pD formats (dentry/file pathname, up to 4 last
  components) + several long-standing patches from various folks.

  There definitely will be a lot more (starting with Miklos'
  check_submount_and_drop() series)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  direct-io: Handle O_(D)SYNC AIO
  direct-io: Implement generic deferred AIO completions
  add formats for dentry/file pathnames
  kvm eventfd: switch to fdget
  powerpc kvm: use fdget
  switch fchmod() to fdget
  switch epoll_ctl() to fdget
  switch copy_module_from_fd() to fdget
  git simplify nilfs check for busy subtree
  ibmasmfs: don't bother passing superblock when not needed
  don't pass superblock to hypfs_{mkdir,create*}
  don't pass superblock to hypfs_diag_create_files
  don't pass superblock to hypfs_vm_create_files()
  oprofile: get rid of pointless forward declarations of struct super_block
  oprofilefs_create_...() do not need superblock argument
  oprofilefs_mkdir() doesn't need superblock argument
  don't bother with passing superblock to oprofile_create_stats_files()
  oprofile: don't bother with passing superblock to ->create_files()
  don't bother passing sb to oprofile_create_files()
  coh901318: don't open-code simple_read_from_buffer()
  ...

lib/vsprintf.c

@@ -26,6 +26,7 @@
 #include <linux/math64.h>
 #include <linux/uaccess.h>
 #include <linux/ioport.h>
+#include <linux/dcache.h>
 #include <net/addrconf.h>
 
 #include <asm/page.h>		/* for PAGE_SIZE */
@@ -532,6 +533,81 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
 	return buf;
 }
 
+static void widen(char *buf, char *end, unsigned len, unsigned spaces)
+{
+	size_t size;
+	if (buf >= end)	/* nowhere to put anything */
+		return;
+	size = end - buf;
+	if (size <= spaces) {
+		memset(buf, ' ', size);
+		return;
+	}
+	if (len) {
+		if (len > size - spaces)
+			len = size - spaces;
+		memmove(buf + spaces, buf, len);
+	}
+	memset(buf, ' ', spaces);
+}
+
+static noinline_for_stack
+char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
+		  const char *fmt)
+{
+	const char *array[4], *s;
+	const struct dentry *p;
+	int depth;
+	int i, n;
+
+	switch (fmt[1]) {
+		case '2': case '3': case '4':
+			depth = fmt[1] - '0';
+			break;
+		default:
+			depth = 1;
+	}
+
+	rcu_read_lock();
+	for (i = 0; i < depth; i++, d = p) {
+		p = ACCESS_ONCE(d->d_parent);
+		array[i] = ACCESS_ONCE(d->d_name.name);
+		if (p == d) {
+			if (i)
+				array[i] = "";
+			i++;
+			break;
+		}
+	}
+	s = array[--i];
+	for (n = 0; n != spec.precision; n++, buf++) {
+		char c = *s++;
+		if (!c) {
+			if (!i)
+				break;
+			c = '/';
+			s = array[--i];
+		}
+		if (buf < end)
+			*buf = c;
+	}
+	rcu_read_unlock();
+	if (n < spec.field_width) {
+		/* we want to pad the sucker */
+		unsigned spaces = spec.field_width - n;
+		if (!(spec.flags & LEFT)) {
+			widen(buf - n, end, n, spaces);
+			return buf + spaces;
+		}
+		while (spaces--) {
+			if (buf < end)
+				*buf = ' ';
+			++buf;
+		}
+	}
+	return buf;
+}
+
 static noinline_for_stack
 char *symbol_string(char *buf, char *end, void *ptr,
 		    struct printf_spec spec, const char *fmt)
@@ -1253,6 +1329,12 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 		spec.base = 16;
 		return number(buf, end,
 			      (unsigned long long) *((phys_addr_t *)ptr), spec);
+	case 'd':
+		return dentry_name(buf, end, ptr, spec, fmt);
+	case 'D':
+		return dentry_name(buf, end,
+				   ((const struct file *)ptr)->f_path.dentry,
+				   spec, fmt);
 	}
 	spec.flags |= SMALL;
 	if (spec.field_width == -1) {