Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  fs: simplify iget & friends
  fs: pull inode->i_lock up out of writeback_single_inode
  fs: rename inode_lock to inode_hash_lock
  fs: move i_wb_list out from under inode_lock
  fs: move i_sb_list out from under inode_lock
  fs: remove inode_lock from iput_final and prune_icache
  fs: Lock the inode LRU list separately
  fs: factor inode disposal
  fs: protect inode->i_state with inode->i_lock
  autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
  autofs4 - remove autofs4_lock
  autofs4 - fix d_manage() return on rcu-walk
  autofs4 - fix autofs4_expire_indirect() traversal
  autofs4 - fix dentry leak in autofs4_expire_direct()
  autofs4 - reinstate last used update on access
  vfs - check non-mountpoint dentry might block in __follow_mount_rcu()

1 files changed, 25 insertions, 17 deletions

diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 4c29fcf557d1..07ea8d3e6ea2 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -22,13 +22,14 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
-#include <linux/writeback.h> /* for inode_lock */
 
 #include <asm/atomic.h>
 
 #include <linux/fsnotify_backend.h>
 #include "fsnotify.h"
 
+#include "../internal.h"
+
 /*
  * Recalculate the mask of events relevant to a given inode locked.
  */
@@ -237,15 +238,14 @@ out:
  * fsnotify_unmount_inodes - an sb is unmounting.  handle any watched inodes.
  * @list: list of inodes being unmounted (sb->s_inodes)
  *
- * Called with inode_lock held, protecting the unmounting super block's list
- * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
- * We temporarily drop inode_lock, however, and CAN block.
+ * Called during unmount with no locks held, so needs to be safe against
+ * concurrent modifiers. We temporarily drop inode_sb_list_lock and CAN block.
  */
 void fsnotify_unmount_inodes(struct list_head *list)
 {
 	struct inode *inode, *next_i, *need_iput = NULL;
 
-	spin_lock(&inode_lock);
+	spin_lock(&inode_sb_list_lock);
 	list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
 		struct inode *need_iput_tmp;
 
@@ -254,8 +254,11 @@ void fsnotify_unmount_inodes(struct list_head *list)
 		 * I_WILL_FREE, or I_NEW which is fine because by that point
 		 * the inode cannot have any associated watches.
 		 */
-		if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+		spin_lock(&inode->i_lock);
+		if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		/*
 		 * If i_count is zero, the inode cannot have any watches and
@@ -263,8 +266,10 @@ void fsnotify_unmount_inodes(struct list_head *list)
 		 * evict all inodes with zero i_count from icache which is
 		 * unnecessarily violent and may in fact be illegal to do.
 		 */
-		if (!atomic_read(&inode->i_count))
+		if (!atomic_read(&inode->i_count)) {
+			spin_unlock(&inode->i_lock);
 			continue;
+		}
 
 		need_iput_tmp = need_iput;
 		need_iput = NULL;
@@ -274,22 +279,25 @@ void fsnotify_unmount_inodes(struct list_head *list)
 			__iget(inode);
 		else
 			need_iput_tmp = NULL;
+		spin_unlock(&inode->i_lock);
 
 		/* In case the dropping of a reference would nuke next_i. */
 		if ((&next_i->i_sb_list != list) &&
-		    atomic_read(&next_i->i_count) &&
-		    !(next_i->i_state & (I_FREEING | I_WILL_FREE))) {
-			__iget(next_i);
-			need_iput = next_i;
+		    atomic_read(&next_i->i_count)) {
+			spin_lock(&next_i->i_lock);
+			if (!(next_i->i_state & (I_FREEING | I_WILL_FREE))) {
+				__iget(next_i);
+				need_iput = next_i;
+			}
+			spin_unlock(&next_i->i_lock);
 		}
 
 		/*
-		 * We can safely drop inode_lock here because we hold
+		 * We can safely drop inode_sb_list_lock here because we hold
 		 * references on both inode and next_i.  Also no new inodes
-		 * will be added since the umount has begun.  Finally,
-		 * iprune_mutex keeps shrink_icache_memory() away.
+		 * will be added since the umount has begun.
 		 */
-		spin_unlock(&inode_lock);
+		spin_unlock(&inode_sb_list_lock);
 
 		if (need_iput_tmp)
 			iput(need_iput_tmp);
@@ -301,7 +309,7 @@ void fsnotify_unmount_inodes(struct list_head *list)
 
 		iput(inode);
 
-		spin_lock(&inode_lock);
+		spin_lock(&inode_sb_list_lock);
 	}
-	spin_unlock(&inode_lock);
+	spin_unlock(&inode_sb_list_lock);
 }