xfs_buf_delwri_pushbuf synchronously writes a buffer that is on a delwri
list already. Instead of doing a complicated dance with the delwri
and wait list, just leave them alone and open code the actual buffer
write.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
fs/xfs/xfs_buf.c | 33 ++++++++-------------------------
1 file changed, 8 insertions(+), 25 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 5abada2b4a4a..fba494b9b9da 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -2384,14 +2384,9 @@ xfs_buf_delwri_submit(
* Push a single buffer on a delwri queue.
*
* The purpose of this function is to submit a single buffer of a delwri queue
- * and return with the buffer still on the original queue. The waiting delwri
- * buffer submission infrastructure guarantees transfer of the delwri queue
- * buffer reference to a temporary wait list. We reuse this infrastructure to
- * transfer the buffer back to the original queue.
+ * and return with the buffer still on the original queue.
*
- * Note the buffer transitions from the queued state, to the submitted and wait
- * listed state and back to the queued state during this call. The buffer
- * locking and queue management logic between _delwri_pushbuf() and
+ * The buffer locking and queue management logic between _delwri_pushbuf() and
* _delwri_queue() guarantee that the buffer cannot be queued to another list
* before returning.
*/
@@ -2400,33 +2395,21 @@ xfs_buf_delwri_pushbuf(
struct xfs_buf *bp,
struct list_head *buffer_list)
{
- LIST_HEAD (submit_list);
int error;
ASSERT(bp->b_flags & _XBF_DELWRI_Q);
trace_xfs_buf_delwri_pushbuf(bp, _RET_IP_);
- /*
- * Isolate the buffer to a new local list so we can submit it for I/O
- * independently from the rest of the original list.
- */
xfs_buf_lock(bp);
- list_move(&bp->b_list, &submit_list);
- xfs_buf_unlock(bp);
-
- /*
- * Delwri submission clears the DELWRI_Q buffer flag and returns with
- * the buffer on the wait list with the original reference. Rather than
- * bounce the buffer from a local wait list back to the original list
- * after I/O completion, reuse the original list as the wait list.
- */
- xfs_buf_delwri_submit_buffers(&submit_list, buffer_list);
+ bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC);
+ bp->b_flags |= XBF_WRITE;
+ xfs_buf_submit(bp);
/*
- * The buffer is now locked, under I/O and wait listed on the original
- * delwri queue. Wait for I/O completion, restore the DELWRI_Q flag and
- * return with the buffer unlocked and on the original queue.
+ * The buffer is now locked, under I/O but still on the original delwri
+ * queue. Wait for I/O completion, restore the DELWRI_Q flag and
+ * return with the buffer unlocked and still on the original queue.
*/
error = xfs_buf_iowait(bp);
bp->b_flags |= _XBF_DELWRI_Q;
--
2.45.2
