Merge tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg Kroah-Hartman:
 "Here's the driver core, and other driver subsystems, pull request for
  the 3.5-rc1 merge window.

  Outside of a few minor driver core changes, we ended up with the
  following different subsystem and core changes as well, due to
  interdependancies on the driver core:
   - hyperv driver updates
   - drivers/memory being created and some drivers moved into it
   - extcon driver subsystem created out of the old Android staging
     switch driver code
   - dynamic debug updates
   - printk rework, and /dev/kmsg changes

  All of this has been tested in the linux-next releases for a few weeks
  with no reported problems.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fix up conflicts in drivers/extcon/extcon-max8997.c where git noticed
that a patch to the deleted drivers/misc/max8997-muic.c driver needs to
be applied to this one.

* tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (90 commits)
  uio_pdrv_genirq: get irq through platform resource if not set otherwise
  memory: tegra{20,30}-mc: Remove empty *_remove()
  printk() - isolate KERN_CONT users from ordinary complete lines
  sysfs: get rid of some lockdep false positives
  Drivers: hv: util: Properly handle version negotiations.
  Drivers: hv: Get rid of an unnecessary check in vmbus_prep_negotiate_resp()
  memory: tegra{20,30}-mc: Use dev_err_ratelimited()
  driver core: Add dev_*_ratelimited() family
  Driver Core: don't oops with unregistered driver in driver_find_device()
  printk() - restore prefix/timestamp printing for multi-newline strings
  printk: add stub for prepend_timestamp()
  ARM: tegra30: Make MC optional in Kconfig
  ARM: tegra20: Make MC optional in Kconfig
  ARM: tegra30: MC: Remove unnecessary BUG*()
  ARM: tegra20: MC: Remove unnecessary BUG*()
  printk: correctly align __log_buf
  ARM: tegra30: Add Tegra Memory Controller(MC) driver
  ARM: tegra20: Add Tegra Memory Controller(MC) driver
  printk() - restore timestamp printing at console output
  printk() - do not merge continuation lines of different threads
  ...

1 files changed, 28 insertions, 9 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 35a36d39fa2c..e6bb9b2a4cbe 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -132,6 +132,24 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
 	rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+/* Test for attributes that want to ignore lockdep for read-locking */
+static bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+	return sysfs_type(sd) == SYSFS_KOBJ_ATTR &&
+			sd->s_attr.attr->ignore_lockdep;
+}
+
+#else
+
+static inline bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+	return true;
+}
+
+#endif
+
 /**
  *	sysfs_get_active - get an active reference to sysfs_dirent
  *	@sd: sysfs_dirent to get an active reference to
@@ -155,15 +173,17 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
 			return NULL;
 
 		t = atomic_cmpxchg(&sd->s_active, v, v + 1);
-		if (likely(t == v)) {
-			rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
-			return sd;
-		}
+		if (likely(t == v))
+			break;
 		if (t < 0)
 			return NULL;
 
 		cpu_relax();
 	}
+
+	if (likely(!ignore_lockdep(sd)))
+		rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
+	return sd;
 }
 
 /**
@@ -180,7 +200,8 @@ void sysfs_put_active(struct sysfs_dirent *sd)
 	if (unlikely(!sd))
 		return;
 
-	rwsem_release(&sd->dep_map, 1, _RET_IP_);
+	if (likely(!ignore_lockdep(sd)))
+		rwsem_release(&sd->dep_map, 1, _RET_IP_);
 	v = atomic_dec_return(&sd->s_active);
 	if (likely(v != SD_DEACTIVATED_BIAS))
 		return;
@@ -858,7 +879,6 @@ int sysfs_rename(struct sysfs_dirent *sd,
 	struct sysfs_dirent *new_parent_sd, const void *new_ns,
 	const char *new_name)
 {
-	const char *dup_name = NULL;
 	int error;
 
 	mutex_lock(&sysfs_mutex);
@@ -875,11 +895,11 @@ int sysfs_rename(struct sysfs_dirent *sd,
 	/* rename sysfs_dirent */
 	if (strcmp(sd->s_name, new_name) != 0) {
 		error = -ENOMEM;
-		new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+		new_name = kstrdup(new_name, GFP_KERNEL);
 		if (!new_name)
 			goto out;
 
-		dup_name = sd->s_name;
+		kfree(sd->s_name);
 		sd->s_name = new_name;
 	}
 
@@ -895,7 +915,6 @@ int sysfs_rename(struct sysfs_dirent *sd,
 	error = 0;
  out:
 	mutex_unlock(&sysfs_mutex);
-	kfree(dup_name);
 	return error;
 }