1 files changed, 60 insertions, 4 deletions

diff --git a/fs/inode.c b/fs/inode.c
index deb72f6c2b4f..c474c1d7062b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -486,7 +486,7 @@ void __remove_inode_hash(struct inode *inode)
 }
 EXPORT_SYMBOL(__remove_inode_hash);
 
-void end_writeback(struct inode *inode)
+void clear_inode(struct inode *inode)
 {
 	might_sleep();
 	/*
@@ -500,11 +500,10 @@ void end_writeback(struct inode *inode)
 	BUG_ON(!list_empty(&inode->i_data.private_list));
 	BUG_ON(!(inode->i_state & I_FREEING));
 	BUG_ON(inode->i_state & I_CLEAR);
-	inode_sync_wait(inode);
 	/* don't need i_lock here, no concurrent mods to i_state */
 	inode->i_state = I_FREEING | I_CLEAR;
 }
-EXPORT_SYMBOL(end_writeback);
+EXPORT_SYMBOL(clear_inode);
 
 /*
  * Free the inode passed in, removing it from the lists it is still connected
@@ -531,12 +530,20 @@ static void evict(struct inode *inode)
 
 	inode_sb_list_del(inode);
 
+	/*
+	 * Wait for flusher thread to be done with the inode so that filesystem
+	 * does not start destroying it while writeback is still running. Since
+	 * the inode has I_FREEING set, flusher thread won't start new work on
+	 * the inode.  We just have to wait for running writeback to finish.
+	 */
+	inode_wait_for_writeback(inode);
+
 	if (op->evict_inode) {
 		op->evict_inode(inode);
 	} else {
 		if (inode->i_data.nrpages)
 			truncate_inode_pages(&inode->i_data, 0);
-		end_writeback(inode);
+		clear_inode(inode);
 	}
 	if (S_ISBLK(inode->i_mode) && inode->i_bdev)
 		bd_forget(inode);
@@ -1647,6 +1654,7 @@ void __init inode_init_early(void)
 					HASH_EARLY,
 					&i_hash_shift,
 					&i_hash_mask,
+					0,
 					0);
 
 	for (loop = 0; loop < (1U << i_hash_shift); loop++)
@@ -1677,6 +1685,7 @@ void __init inode_init(void)
 					0,
 					&i_hash_shift,
 					&i_hash_mask,
+					0,
 					0);
 
 	for (loop = 0; loop < (1U << i_hash_shift); loop++)
@@ -1739,3 +1748,50 @@ bool inode_owner_or_capable(const struct inode *inode)
 	return false;
 }
 EXPORT_SYMBOL(inode_owner_or_capable);
+
+/*
+ * Direct i/o helper functions
+ */
+static void __inode_dio_wait(struct inode *inode)
+{
+	wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_DIO_WAKEUP);
+	DEFINE_WAIT_BIT(q, &inode->i_state, __I_DIO_WAKEUP);
+
+	do {
+		prepare_to_wait(wq, &q.wait, TASK_UNINTERRUPTIBLE);
+		if (atomic_read(&inode->i_dio_count))
+			schedule();
+	} while (atomic_read(&inode->i_dio_count));
+	finish_wait(wq, &q.wait);
+}
+
+/**
+ * inode_dio_wait - wait for outstanding DIO requests to finish
+ * @inode: inode to wait for
+ *
+ * Waits for all pending direct I/O requests to finish so that we can
+ * proceed with a truncate or equivalent operation.
+ *
+ * Must be called under a lock that serializes taking new references
+ * to i_dio_count, usually by inode->i_mutex.
+ */
+void inode_dio_wait(struct inode *inode)
+{
+	if (atomic_read(&inode->i_dio_count))
+		__inode_dio_wait(inode);
+}
+EXPORT_SYMBOL(inode_dio_wait);
+
+/*
+ * inode_dio_done - signal finish of a direct I/O requests
+ * @inode: inode the direct I/O happens on
+ *
+ * This is called once we've finished processing a direct I/O request,
+ * and is used to wake up callers waiting for direct I/O to be quiesced.
+ */
+void inode_dio_done(struct inode *inode)
+{
+	if (atomic_dec_and_test(&inode->i_dio_count))
+		wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
+}
+EXPORT_SYMBOL(inode_dio_done);