[PATCH 01/15] xfs: fix a double completion for buffers on in-memory targets

[Christoph Hellwig <hch@lst.de>]

__xfs_buf_submit calls xfs_buf_ioend when b_io_remaining hits zero.  For
in-memory buftargs b_io_remaining is never incremented from it's initial
value of 1, so this always happens.  Thus the extra call to xfs_buf_ioend
in _xfs_buf_ioapply causes a double completion.  Fortunately
__xfs_buf_submit is only used for synchronous reads on in-memory buftargs
due to the peculiarities of how they work, so this is mostly harmless and
just causes a little extra work to be done.

Fixes: 5076a6040ca1 ("xfs: support in-memory buffer cache targets")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_buf.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index aa63b8efd782..787caf0c3254 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1656,10 +1656,8 @@ _xfs_buf_ioapply(
 	op |= REQ_META;
 
 	/* in-memory targets are directly mapped, no IO required. */
-	if (xfs_buftarg_is_mem(bp->b_target)) {
-		xfs_buf_ioend(bp);
+	if (xfs_buftarg_is_mem(bp->b_target))
 		return;
-	}
 
 	/*
 	 * Walk all the vectors issuing IO on them. Set up the initial offset
-- 
2.45.2