[PATCH 1/3] xfs: ensure buffer types are set correctly

[Dave Chinner]

From: Dave Chinner <dchinner at redhat.com>

Jan Kara reported that log recovery was finding buffers with invalid
types in them. This should not happen, and indicates a bug in the
logging of buffers. To catch this, add asserts to the buffer
formatting code to ensure that the buffer type is in range when the
transaction is committed.

We don't set a type on buffers being marked stale - they are not
going to get replayed, the format item exists only for recovery to
be able to prevent replay of the buffer, so the type does not
matter. Hence that needs special casing here.

Reported-by: Jan Kara <jack at suse.cz>
Signed-off-by: Dave Chinner <dchinner at redhat.com>
---
 fs/xfs/xfs_buf_item.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 925ead2..507d96a 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -319,6 +319,10 @@ xfs_buf_item_format(
 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
 	ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
 	       (bip->bli_flags & XFS_BLI_STALE));
+	ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
+	       (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
+	        && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
+
 
 	/*
 	 * If it is an inode buffer, transfer the in-memory state to the
-- 
2.0.0