kill xfs_buf_iostart

xfs_buf_iostart is a "shared" helper for xfs_buf_read_flags,
xfs_bawrite, and xfs_bdwrite - except that there isn't much shared
code but rather special cases for each caller.

So remove this function and move the functionality to the caller.
xfs_bawrite and xfs_bdwrite are now big enough to be moved out of
line and the xfs_buf_read_flags is moved into a new helper called
_xfs_buf_read.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

2 files changed, 50 insertions, 56 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 36d5fcd3f593..cd89c56715a5 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -630,6 +630,29 @@ xfs_buf_get_flags(
         return NULL;
 }
 
+STATIC int
+_xfs_buf_read(
+        xfs_buf_t               *bp,
+        xfs_buf_flags_t         flags)
+{
+        int                     status;
+
+        XB_TRACE(bp, "_xfs_buf_read", (unsigned long)flags);
+
+        ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE)));
+        ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
+
+        bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \
+                        XBF_READ_AHEAD | _XBF_RUN_QUEUES);
+        bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \
+                        XBF_READ_AHEAD | _XBF_RUN_QUEUES);
+
+        status = xfs_buf_iorequest(bp);
+        if (!status && !(flags & XBF_ASYNC))
+                status = xfs_buf_iowait(bp);
+        return status;
+}
+
 xfs_buf_t *
 xfs_buf_read_flags(
         xfs_buftarg_t           *target,
@@ -646,7 +669,7 @@ xfs_buf_read_flags(
                 if (!XFS_BUF_ISDONE(bp)) {
                         XB_TRACE(bp, "read", (unsigned long)flags);
                         XFS_STATS_INC(xb_get_read);
-                        xfs_buf_iostart(bp, flags);
+                        _xfs_buf_read(bp, flags);
                 } else if (flags & XBF_ASYNC) {
                         XB_TRACE(bp, "read_async", (unsigned long)flags);
                         /*
@@ -1048,50 +1071,39 @@ xfs_buf_ioerror(
         XB_TRACE(bp, "ioerror", (unsigned long)error);
 }
 
-/*
- *      Initiate I/O on a buffer, based on the flags supplied.
- *      The b_iodone routine in the buffer supplied will only be called
- *      when all of the subsidiary I/O requests, if any, have been completed.
- */
 int
-xfs_buf_iostart(
-        xfs_buf_t               *bp,
-        xfs_buf_flags_t         flags)
+xfs_bawrite(
+        void                    *mp,
+        struct xfs_buf          *bp)
 {
-        int                     status = 0;
+        XB_TRACE(bp, "bawrite", 0);
 
-        XB_TRACE(bp, "iostart", (unsigned long)flags);
+        ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
 
-        if (flags & XBF_DELWRI) {
-                bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC);
-                bp->b_flags |= flags & (XBF_DELWRI | XBF_ASYNC);
-                xfs_buf_delwri_queue(bp, 1);
-                return 0;
-        }
+        xfs_buf_delwri_dequeue(bp);
 
-        bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \
-                        XBF_READ_AHEAD | _XBF_RUN_QUEUES);
-        bp->b_flags |= flags & (XBF_READ | XBF_WRITE | XBF_ASYNC | \
-                        XBF_READ_AHEAD | _XBF_RUN_QUEUES);
+        bp->b_flags &= ~(XBF_READ | XBF_DELWRI | XBF_READ_AHEAD);
+        bp->b_flags |= (XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES);
+
+        bp->b_fspriv3 = mp;
+        bp->b_strat = xfs_bdstrat_cb;
+        return xfs_bdstrat_cb(bp);
+}
 
-        BUG_ON(bp->b_bn == XFS_BUF_DADDR_NULL);
+void
+xfs_bdwrite(
+        void                    *mp,
+        struct xfs_buf          *bp)
+{
+        XB_TRACE(bp, "bdwrite", 0);
 
-        /* For writes allow an alternate strategy routine to precede
-         * the actual I/O request (which may not be issued at all in
-         * a shutdown situation, for example).
-         */
-        status = (flags & XBF_WRITE) ?
-                xfs_buf_iostrategy(bp) : xfs_buf_iorequest(bp);
+        bp->b_strat = xfs_bdstrat_cb;
+        bp->b_fspriv3 = mp;
 
-        /* Wait for I/O if we are not an async request.
-         * Note: async I/O request completion will release the buffer,
-         * and that can already be done by this point.  So using the
-         * buffer pointer from here on, after async I/O, is invalid.
-         */
-        if (!status && !(flags & XBF_ASYNC))
-                status = xfs_buf_iowait(bp);
+        bp->b_flags &= ~XBF_READ;
+        bp->b_flags |= (XBF_DELWRI | XBF_ASYNC);
 
-        return status;
+        xfs_buf_delwri_queue(bp, 1);
 }
 
 STATIC_INLINE void
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 456519a088c7..0e2aa16f5e41 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -214,9 +214,10 @@ extern void xfs_buf_lock(xfs_buf_t *);
 extern void xfs_buf_unlock(xfs_buf_t *);
 
 /* Buffer Read and Write Routines */
+extern int xfs_bawrite(void *mp, xfs_buf_t *bp);
+extern void xfs_bdwrite(void *mp, xfs_buf_t *bp);
 extern void xfs_buf_ioend(xfs_buf_t *,  int);
 extern void xfs_buf_ioerror(xfs_buf_t *, int);
-extern int xfs_buf_iostart(xfs_buf_t *, xfs_buf_flags_t);
 extern int xfs_buf_iorequest(xfs_buf_t *);
 extern int xfs_buf_iowait(xfs_buf_t *);
 extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, xfs_caddr_t,
@@ -366,14 +367,6 @@ extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *);
 #define XFS_BUF_TARGET(bp)              ((bp)->b_target)
 #define XFS_BUFTARG_NAME(target)        xfs_buf_target_name(target)
 
-static inline int xfs_bawrite(void *mp, xfs_buf_t *bp)
-{
-        bp->b_fspriv3 = mp;
-        bp->b_strat = xfs_bdstrat_cb;
-        xfs_buf_delwri_dequeue(bp);
-        return xfs_buf_iostart(bp, XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES);
-}
-
 static inline void xfs_buf_relse(xfs_buf_t *bp)
 {
         if (!bp->b_relse)
@@ -414,17 +407,6 @@ static inline int XFS_bwrite(xfs_buf_t *bp)
         return error;
 }
 
-/*
- * No error can be returned from xfs_buf_iostart for delwri
- * buffers as they are queued and no I/O is issued.
- */
-static inline void xfs_bdwrite(void *mp, xfs_buf_t *bp)
-{
-        bp->b_strat = xfs_bdstrat_cb;
-        bp->b_fspriv3 = mp;
-        (void)xfs_buf_iostart(bp, XBF_DELWRI | XBF_ASYNC);
-}
-
 #define XFS_bdstrat(bp) xfs_buf_iorequest(bp)
 
 #define xfs_iowait(bp)  xfs_buf_iowait(bp)