[PATCH 04/24] xfs: mark dquot buffers in cache

[Dave Chinner <david@fromorbit.com>]

dquot buffers always have write IO callbacks, so by marking them
directly we can avoid needing to attach ->b_iodone functions to
them. This avoids an indirect call, and makes future modifications
much simpler.

This is largely a rearrangement of the code at this point - no IO
completion functionality changes at this point, just how the
code is run is modified.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/xfs_buf.c       | 12 +++++++++++-
 fs/xfs/xfs_buf.h       |  2 ++
 fs/xfs/xfs_buf_item.c  | 10 ++++++++++
 fs/xfs/xfs_buf_item.h  |  1 +
 fs/xfs/xfs_dquot.c     |  1 +
 fs/xfs/xfs_trans_buf.c |  1 +
 6 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 6105b97028d6a..77d40eb4a11db 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1204,17 +1204,27 @@ xfs_buf_ioend(
 		bp->b_flags |= XBF_DONE;
 	}
 
+	if (read)
+		goto out_finish;
+
 	/* inodes always have a callback on write */
-	if (!read && (bp->b_flags & _XBF_INODES)) {
+	if (bp->b_flags & _XBF_INODES) {
 		xfs_buf_inode_iodone(bp);
 		return;
 	}
 
+	/* dquots always have a callback on write */
+	if (bp->b_flags & _XBF_DQUOTS) {
+		xfs_buf_dquot_iodone(bp);
+		return;
+	}
+
 	if (bp->b_iodone) {
 		(*(bp->b_iodone))(bp);
 		return;
 	}
 
+out_finish:
 	xfs_buf_ioend_finish(bp);
 }
 
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index b3e5d653d09f1..cbde44ecb3963 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -32,6 +32,7 @@
 
 /* buffer type flags for write callbacks */
 #define _XBF_INODES	 (1 << 16)/* inode buffer */
+#define _XBF_DQUOTS	 (1 << 17)/* dquot buffer */
 
 /* flags used only internally */
 #define _XBF_PAGES	 (1 << 20)/* backed by refcounted pages */
@@ -55,6 +56,7 @@ typedef unsigned int xfs_buf_flags_t;
 	{ XBF_STALE,		"STALE" }, \
 	{ XBF_WRITE_FAIL,	"WRITE_FAIL" }, \
 	{ _XBF_INODES,		"INODES" }, \
+	{ _XBF_DQUOTS,		"DQUOTS" }, \
 	{ _XBF_PAGES,		"PAGES" }, \
 	{ _XBF_KMEM,		"KMEM" }, \
 	{ _XBF_DELWRI_Q,	"DELWRI_Q" }, \
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 8659cf4282a64..a42cdf9ccc47d 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -1210,6 +1210,16 @@ xfs_buf_inode_iodone(
 	xfs_buf_ioend_finish(bp);
 }
 
+/*
+ * Dquot buffer iodone callback function.
+ */
+void
+xfs_buf_dquot_iodone(
+	struct xfs_buf		*bp)
+{
+	xfs_buf_run_callbacks(bp);
+	xfs_buf_ioend_finish(bp);
+}
 
 /*
  * This is the iodone() function for buffers which have been
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index a342933ad9b8d..27d13d29b5bbb 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -60,6 +60,7 @@ void	xfs_buf_attach_iodone(struct xfs_buf *,
 void	xfs_buf_iodone_callbacks(struct xfs_buf *);
 void	xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
 void	xfs_buf_inode_iodone(struct xfs_buf *);
+void	xfs_buf_dquot_iodone(struct xfs_buf *);
 bool	xfs_buf_log_check_iovec(struct xfs_log_iovec *iovec);
 
 extern kmem_zone_t	*xfs_buf_item_zone;
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 55b95d45303b8..25592b701db40 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -1174,6 +1174,7 @@ xfs_qm_dqflush(
 	 * Attach an iodone routine so that we can remove this dquot from the
 	 * AIL and release the flush lock once the dquot is synced to disk.
 	 */
+	bp->b_flags |= _XBF_DQUOTS;
 	xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
 				  &dqp->q_logitem.qli_item);
 
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 552d0869aa0fe..93d62cb864c15 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -788,5 +788,6 @@ xfs_trans_dquot_buf(
 		break;
 	}
 
+	bp->b_flags |= _XBF_DQUOTS;
 	xfs_trans_buf_set_type(tp, bp, type);
 }
-- 
2.26.2.761.g0e0b3e54be