1 files changed, 25 insertions, 10 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c8921589e2f3..b12850b31cb3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3482,15 +3482,21 @@ zeroit:
 void btrfs_add_delayed_iput(struct btrfs_inode *inode)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	unsigned long flags;
 
 	if (atomic_add_unless(&inode->vfs_inode.i_count, -1, 1))
 		return;
 
 	atomic_inc(&fs_info->nr_delayed_iputs);
-	spin_lock(&fs_info->delayed_iput_lock);
+	/*
+	 * Need to be irq safe here because we can be called from either an irq
+	 * context (see bio.c and btrfs_put_ordered_extent()) or a non-irq
+	 * context.
+	 */
+	spin_lock_irqsave(&fs_info->delayed_iput_lock, flags);
 	ASSERT(list_empty(&inode->delayed_iput));
 	list_add_tail(&inode->delayed_iput, &fs_info->delayed_iputs);
-	spin_unlock(&fs_info->delayed_iput_lock);
+	spin_unlock_irqrestore(&fs_info->delayed_iput_lock, flags);
 	if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
 		wake_up_process(fs_info->cleaner_kthread);
 }
@@ -3499,37 +3505,46 @@ static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
 				    struct btrfs_inode *inode)
 {
 	list_del_init(&inode->delayed_iput);
-	spin_unlock(&fs_info->delayed_iput_lock);
+	spin_unlock_irq(&fs_info->delayed_iput_lock);
 	iput(&inode->vfs_inode);
 	if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
 		wake_up(&fs_info->delayed_iputs_wait);
-	spin_lock(&fs_info->delayed_iput_lock);
+	spin_lock_irq(&fs_info->delayed_iput_lock);
 }
 
 static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
 				   struct btrfs_inode *inode)
 {
 	if (!list_empty(&inode->delayed_iput)) {
-		spin_lock(&fs_info->delayed_iput_lock);
+		spin_lock_irq(&fs_info->delayed_iput_lock);
 		if (!list_empty(&inode->delayed_iput))
 			run_delayed_iput_locked(fs_info, inode);
-		spin_unlock(&fs_info->delayed_iput_lock);
+		spin_unlock_irq(&fs_info->delayed_iput_lock);
 	}
 }
 
 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
 {
-
-	spin_lock(&fs_info->delayed_iput_lock);
+	/*
+	 * btrfs_put_ordered_extent() can run in irq context (see bio.c), which
+	 * calls btrfs_add_delayed_iput() and that needs to lock
+	 * fs_info->delayed_iput_lock. So we need to disable irqs here to
+	 * prevent a deadlock.
+	 */
+	spin_lock_irq(&fs_info->delayed_iput_lock);
 	while (!list_empty(&fs_info->delayed_iputs)) {
 		struct btrfs_inode *inode;
 
 		inode = list_first_entry(&fs_info->delayed_iputs,
 				struct btrfs_inode, delayed_iput);
 		run_delayed_iput_locked(fs_info, inode);
-		cond_resched_lock(&fs_info->delayed_iput_lock);
+		if (need_resched()) {
+			spin_unlock_irq(&fs_info->delayed_iput_lock);
+			cond_resched();
+			spin_lock_irq(&fs_info->delayed_iput_lock);
+		}
 	}
-	spin_unlock(&fs_info->delayed_iput_lock);
+	spin_unlock_irq(&fs_info->delayed_iput_lock);
 }
 
 /*