Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 286a287..b5b3a78 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -10,11 +10,9 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
-#include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_buf_item.h"
 #include "xfs_trans_priv.h"
-#include "xfs_error.h"
 #include "xfs_trace.h"
 
 /*
@@ -174,8 +172,7 @@
 xfs_buf_t *
 xfs_trans_getsb(
 	xfs_trans_t		*tp,
-	struct xfs_mount	*mp,
-	int			flags)
+	struct xfs_mount	*mp)
 {
 	xfs_buf_t		*bp;
 	struct xfs_buf_log_item	*bip;
@@ -185,7 +182,7 @@
 	 * if tp is NULL.
 	 */
 	if (tp == NULL)
-		return xfs_getsb(mp, flags);
+		return xfs_getsb(mp);
 
 	/*
 	 * If the superblock buffer already has this transaction
@@ -203,7 +200,7 @@
 		return bp;
 	}
 
-	bp = xfs_getsb(mp, flags);
+	bp = xfs_getsb(mp);
 	if (bp == NULL)
 		return NULL;
 
@@ -264,11 +261,39 @@
 			return -EIO;
 		}
 
+		/*
+		 * Check if the caller is trying to read a buffer that is
+		 * already attached to the transaction yet has no buffer ops
+		 * assigned.  Ops are usually attached when the buffer is
+		 * attached to the transaction, or by the read caller if
+		 * special circumstances.  That didn't happen, which is not
+		 * how this is supposed to go.
+		 *
+		 * If the buffer passes verification we'll let this go, but if
+		 * not we have to shut down.  Let the transaction cleanup code
+		 * release this buffer when it kills the tranaction.
+		 */
+		ASSERT(bp->b_ops != NULL);
+		error = xfs_buf_reverify(bp, ops);
+		if (error) {
+			xfs_buf_ioerror_alert(bp, __func__);
+
+			if (tp->t_flags & XFS_TRANS_DIRTY)
+				xfs_force_shutdown(tp->t_mountp,
+						SHUTDOWN_META_IO_ERROR);
+
+			/* bad CRC means corrupted metadata */
+			if (error == -EFSBADCRC)
+				error = -EFSCORRUPTED;
+			return error;
+		}
+
 		bip = bp->b_log_item;
 		bip->bli_recur++;
 
 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
 		trace_xfs_trans_read_buf_recur(bip);
+		ASSERT(bp->b_ops != NULL || ops == NULL);
 		*bpp = bp;
 		return 0;
 	}
@@ -316,11 +341,25 @@
 		_xfs_trans_bjoin(tp, bp, 1);
 		trace_xfs_trans_read_buf(bp->b_log_item);
 	}
+	ASSERT(bp->b_ops != NULL || ops == NULL);
 	*bpp = bp;
 	return 0;
 
 }
 
+/* Has this buffer been dirtied by anyone? */
+bool
+xfs_trans_buf_is_dirty(
+	struct xfs_buf		*bp)
+{
+	struct xfs_buf_log_item	*bip = bp->b_log_item;
+
+	if (!bip)
+		return false;
+	ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
+	return test_bit(XFS_LI_DIRTY, &bip->bli_item.li_flags);
+}
+
 /*
  * Release a buffer previously joined to the transaction. If the buffer is
  * modified within this transaction, decrement the recursion count but do not
@@ -386,7 +425,7 @@
 
 /*
  * Mark the buffer as not needing to be unlocked when the buf item's
- * iop_unlock() routine is called.  The buffer must already be locked
+ * iop_committing() routine is called.  The buffer must already be locked
  * and associated with the given transaction.
  */
 /* ARGSUSED */