[patch 06/22] kill xfs_buf_iostart

Christoph Hellwig
2008-12-02T16:12:22Z

[-- Attachment #1: xfs-bdwrite_cleanup --]
[-- Type: text/plain, Size: 5726 bytes --]

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.

(First sent on August 2nd)

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: xfs-master/fs/xfs/linux-2.6/xfs_buf.c
===================================================================
--- xfs-master.orig/fs/xfs/linux-2.6/xfs_buf.c 2008-12-01 19:26:04.000000000 +0100
+++ xfs-master/fs/xfs/linux-2.6/xfs_buf.c 2008-12-01 19:27:31.000000000 +0100
@@ -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
Index: xfs-master/fs/xfs/linux-2.6/xfs_buf.h
===================================================================
--- xfs-master.orig/fs/xfs/linux-2.6/xfs_buf.h 2008-12-01 19:26:04.000000000 +0100
+++ xfs-master/fs/xfs/linux-2.6/xfs_buf.h 2008-12-01 19:27:31.000000000 +0100
@@ -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 *, c
#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 *
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)