Merge branch 'linux-3.18.y' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into linux-linaro-lsk-v3.18lsk-v3.18-15.05

* 'linux-3.18.y' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (222 commits)
  Linux 3.18.14
  Drivers: hv: vmbus: Don't wait after requesting offers
  hfsplus: don't store special "osx" xattr prefix on-disk
  drm/radeon: check new address before removing old one
  drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5
  drm/radeon: adjust pll when audio is not enabled
  3w-sas: fix command completion race
  3w-9xxx: fix command completion race
  3w-xxxx: fix command completion race
  ext4: move check under lock scope to close a race.
  ext4: fix data corruption caused by unwritten and delayed extents
  uas: Set max_sectors_240 quirk for ASM1053 devices
  uas: Add US_FL_MAX_SECTORS_240 flag
  uas: Allow uas_use_uas_driver to return usb-storage flags
  rbd: end I/O the entire obj_request on error
  tty/serial: at91: maxburst was missing for dma transfers
  ACPI / SBS: Enable battery manager when present
  btrfs: unlock i_mutex after attempting to delete subvolume during send
  ASoC: rt5677: fixed wrong DMIC ref clock
  ASoC: dapm: Enable autodisable on SOC_DAPM_SINGLE_TLV_AUTODISABLE
  ...

1 files changed, 16 insertions, 15 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index bbde14719655..07ba424181a5 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1322,14 +1322,15 @@ static inline void namespace_lock(void)
 	down_write(&namespace_sem);
 }
 
+enum umount_tree_flags {
+	UMOUNT_SYNC = 1,
+	UMOUNT_PROPAGATE = 2,
+};
 /*
  * mount_lock must be held
  * namespace_sem must be held for write
- * how = 0 => just this tree, don't propagate
- * how = 1 => propagate; we know that nobody else has reference to any victims
- * how = 2 => lazy umount
  */
-void umount_tree(struct mount *mnt, int how)
+static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
 {
 	HLIST_HEAD(tmp_list);
 	struct mount *p;
@@ -1343,7 +1344,7 @@ void umount_tree(struct mount *mnt, int how)
 	hlist_for_each_entry(p, &tmp_list, mnt_hash)
 		list_del_init(&p->mnt_child);
 
-	if (how)
+	if (how & UMOUNT_PROPAGATE)
 		propagate_umount(&tmp_list);
 
 	hlist_for_each_entry(p, &tmp_list, mnt_hash) {
@@ -1351,7 +1352,7 @@ void umount_tree(struct mount *mnt, int how)
 		list_del_init(&p->mnt_list);
 		__touch_mnt_namespace(p->mnt_ns);
 		p->mnt_ns = NULL;
-		if (how < 2)
+		if (how & UMOUNT_SYNC)
 			p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
 		if (mnt_has_parent(p)) {
 			hlist_del_init(&p->mnt_mp_list);
@@ -1456,14 +1457,14 @@ static int do_umount(struct mount *mnt, int flags)
 
 	if (flags & MNT_DETACH) {
 		if (!list_empty(&mnt->mnt_list))
-			umount_tree(mnt, 2);
+			umount_tree(mnt, UMOUNT_PROPAGATE);
 		retval = 0;
 	} else {
 		shrink_submounts(mnt);
 		retval = -EBUSY;
 		if (!propagate_mount_busy(mnt, 2)) {
 			if (!list_empty(&mnt->mnt_list))
-				umount_tree(mnt, 1);
+				umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 			retval = 0;
 		}
 	}
@@ -1495,7 +1496,7 @@ void __detach_mounts(struct dentry *dentry)
 	lock_mount_hash();
 	while (!hlist_empty(&mp->m_list)) {
 		mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
-		umount_tree(mnt, 2);
+		umount_tree(mnt, 0);
 	}
 	unlock_mount_hash();
 	put_mountpoint(mp);
@@ -1662,7 +1663,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
 out:
 	if (res) {
 		lock_mount_hash();
-		umount_tree(res, 0);
+		umount_tree(res, UMOUNT_SYNC);
 		unlock_mount_hash();
 	}
 	return q;
@@ -1686,7 +1687,7 @@ void drop_collected_mounts(struct vfsmount *mnt)
 {
 	namespace_lock();
 	lock_mount_hash();
-	umount_tree(real_mount(mnt), 0);
+	umount_tree(real_mount(mnt), UMOUNT_SYNC);
 	unlock_mount_hash();
 	namespace_unlock();
 }
@@ -1869,7 +1870,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
  out_cleanup_ids:
 	while (!hlist_empty(&tree_list)) {
 		child = hlist_entry(tree_list.first, struct mount, mnt_hash);
-		umount_tree(child, 0);
+		umount_tree(child, UMOUNT_SYNC);
 	}
 	unlock_mount_hash();
 	cleanup_group_ids(source_mnt, NULL);
@@ -2046,7 +2047,7 @@ static int do_loopback(struct path *path, const char *old_name,
 	err = graft_tree(mnt, parent, mp);
 	if (err) {
 		lock_mount_hash();
-		umount_tree(mnt, 0);
+		umount_tree(mnt, UMOUNT_SYNC);
 		unlock_mount_hash();
 	}
 out2:
@@ -2417,7 +2418,7 @@ void mark_mounts_for_expiry(struct list_head *mounts)
 	while (!list_empty(&graveyard)) {
 		mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
 		touch_mnt_namespace(mnt->mnt_ns);
-		umount_tree(mnt, 1);
+		umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 	}
 	unlock_mount_hash();
 	namespace_unlock();
@@ -2488,7 +2489,7 @@ static void shrink_submounts(struct mount *mnt)
 			m = list_first_entry(&graveyard, struct mount,
 						mnt_expire);
 			touch_mnt_namespace(m->mnt_ns);
-			umount_tree(m, 1);
+			umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 		}
 	}
 }