[XFS] split pagebuf_get into xfs_buf_get_flags and xfs_buf_read_flags.

SGI-PV: 923980
SGI-Modid: xfs-linux:xfs-kern:181653a
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/linux-2.6/xfs_buf.c

@@ -486,7 +486,7 @@ _pagebuf_map_pages(
  *	which may imply that this call will block until those buffers
  *	are unlocked.  No I/O is implied by this call.
  */
-STATIC xfs_buf_t *
+xfs_buf_t *
 _pagebuf_find(				/* find buffer for block	*/
 	xfs_buftarg_t		*target,/* target for block		*/
 	loff_t			ioff,	/* starting offset of range	*/
@@ -578,39 +578,14 @@ _pagebuf_find(				/* find buffer for block	*/
 	return (pb);
 }
 
-
 /*
- *	pagebuf_find
+ *	xfs_buf_get_flags assembles a buffer covering the specified range.
  *
- *	pagebuf_find returns a buffer matching the specified range of
- *	data for the specified target, if any of the relevant blocks
- *	are in memory.  The buffer may have unallocated holes, if
- *	some, but not all, of the blocks are in memory.  Even where
- *	pages are present in the buffer, not all of every page may be
- *	valid.
+ *	Storage in memory for all portions of the buffer will be allocated,
+ *	although backing storage may not be.
  */
 xfs_buf_t *
-pagebuf_find(				/* find buffer for block	*/
-					/* if the block is in memory	*/
-	xfs_buftarg_t		*target,/* target for block		*/
-	loff_t			ioff,	/* starting offset of range	*/
-	size_t			isize,	/* length of range		*/
-	page_buf_flags_t	flags)	/* PBF_TRYLOCK			*/
-{
-	return _pagebuf_find(target, ioff, isize, flags, NULL);
-}
-
-/*
- *	pagebuf_get
- *
- *	pagebuf_get assembles a buffer covering the specified range.
- *	Some or all of the blocks in the range may be valid.  Storage
- *	in memory for all portions of the buffer will be allocated,
- *	although backing storage may not be.  If PBF_READ is set in
- *	flags, pagebuf_iostart is called also.
- */
-xfs_buf_t *
-pagebuf_get(				/* allocate a buffer		*/
+xfs_buf_get_flags(			/* allocate a buffer		*/
 	xfs_buftarg_t		*target,/* target for buffer		*/
 	loff_t			ioff,	/* starting offset of range	*/
 	size_t			isize,	/* length of range		*/
@@ -640,8 +615,8 @@ pagebuf_get(				/* allocate a buffer		*/
 	if (!(pb->pb_flags & PBF_MAPPED)) {
 		error = _pagebuf_map_pages(pb, flags);
 		if (unlikely(error)) {
-			printk(KERN_WARNING
-			       "pagebuf_get: failed to map pages\n");
+			printk(KERN_WARNING "%s: failed to map pages\n",
+					__FUNCTION__);
 			goto no_buffer;
 		}
 	}
@@ -655,30 +630,50 @@ pagebuf_get(				/* allocate a buffer		*/
 	pb->pb_bn = ioff;
 	pb->pb_count_desired = pb->pb_buffer_length;
 
-	if (flags & PBF_READ) {
+	PB_TRACE(pb, "get", (unsigned long)flags);
+	return pb;
+
+ no_buffer:
+	if (flags & (PBF_LOCK | PBF_TRYLOCK))
+		pagebuf_unlock(pb);
+	pagebuf_rele(pb);
+	return NULL;
+}
+
+xfs_buf_t *
+xfs_buf_read_flags(
+	xfs_buftarg_t		*target,
+	loff_t			ioff,
+	size_t			isize,
+	page_buf_flags_t	flags)
+{
+	xfs_buf_t		*pb;
+
+	flags |= PBF_READ;
+
+	pb = xfs_buf_get_flags(target, ioff, isize, flags);
+	if (pb) {
 		if (PBF_NOT_DONE(pb)) {
-			PB_TRACE(pb, "get_read", (unsigned long)flags);
+			PB_TRACE(pb, "read", (unsigned long)flags);
 			XFS_STATS_INC(pb_get_read);
 			pagebuf_iostart(pb, flags);
 		} else if (flags & PBF_ASYNC) {
-			PB_TRACE(pb, "get_read_async", (unsigned long)flags);
+			PB_TRACE(pb, "read_async", (unsigned long)flags);
 			/*
 			 * Read ahead call which is already satisfied,
 			 * drop the buffer
 			 */
 			goto no_buffer;
 		} else {
-			PB_TRACE(pb, "get_read_done", (unsigned long)flags);
+			PB_TRACE(pb, "read_done", (unsigned long)flags);
 			/* We do not want read in the flags */
 			pb->pb_flags &= ~PBF_READ;
 		}
-	} else {
-		PB_TRACE(pb, "get_write", (unsigned long)flags);
 	}
 
 	return pb;
 
-no_buffer:
+ no_buffer:
 	if (flags & (PBF_LOCK | PBF_TRYLOCK))
 		pagebuf_unlock(pb);
 	pagebuf_rele(pb);
@@ -724,7 +719,7 @@ pagebuf_readahead(
 		return;
 
 	flags |= (PBF_TRYLOCK|PBF_READ|PBF_ASYNC|PBF_READ_AHEAD);
-	pagebuf_get(target, ioff, isize, flags);
+	xfs_buf_get_flags(target, ioff, isize, flags);
 }
 
 xfs_buf_t *

fs/xfs/linux-2.6/xfs_buf.h

@@ -168,20 +168,36 @@ typedef struct xfs_buf {
 
 /* Finding and Reading Buffers */
 
-extern xfs_buf_t *pagebuf_find(	/* find buffer for block if	*/
+extern xfs_buf_t *_pagebuf_find(	/* find buffer for block if	*/
 					/* the block is in memory	*/
 		xfs_buftarg_t *,	/* inode for block		*/
 		loff_t,			/* starting offset of range	*/
 		size_t,			/* length of range		*/
-		page_buf_flags_t);	/* PBF_LOCK			*/
+		page_buf_flags_t,	/* PBF_LOCK			*/
+	        xfs_buf_t *);		/* newly allocated buffer	*/
 
-extern xfs_buf_t *pagebuf_get(		/* allocate a buffer		*/
+#define xfs_incore(buftarg,blkno,len,lockit) \
+	_pagebuf_find(buftarg, blkno ,len, lockit, NULL)
+
+extern xfs_buf_t *xfs_buf_get_flags(	/* allocate a buffer		*/
 		xfs_buftarg_t *,	/* inode for buffer		*/
 		loff_t,			/* starting offset of range     */
 		size_t,			/* length of range              */
 		page_buf_flags_t);	/* PBF_LOCK, PBF_READ,		*/
 					/* PBF_ASYNC			*/
 
+#define xfs_buf_get(target, blkno, len, flags) \
+	xfs_buf_get_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
+
+extern xfs_buf_t *xfs_buf_read_flags(	/* allocate and read a buffer	*/
+		xfs_buftarg_t *,	/* inode for buffer		*/
+		loff_t,			/* starting offset of range	*/
+		size_t,			/* length of range		*/
+		page_buf_flags_t);	/* PBF_LOCK, PBF_ASYNC		*/
+
+#define xfs_buf_read(target, blkno, len, flags) \
+	xfs_buf_read_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
+
 extern xfs_buf_t *pagebuf_lookup(
 		xfs_buftarg_t *,
 		loff_t,			/* starting offset of range	*/
@@ -472,18 +488,6 @@ extern inline xfs_caddr_t xfs_buf_offset(xfs_buf_t *bp, size_t offset)
 #define XFS_BUF_SET_VTYPE(bp, type)
 #define XFS_BUF_SET_REF(bp, ref)
 
-#define xfs_buf_read(target, blkno, len, flags) \
-		pagebuf_get((target), (blkno), (len), \
-			PBF_LOCK | PBF_READ | PBF_MAPPED)
-#define xfs_buf_get(target, blkno, len, flags) \
-		pagebuf_get((target), (blkno), (len), \
-			PBF_LOCK | PBF_MAPPED)
-
-#define xfs_buf_read_flags(target, blkno, len, flags) \
-		pagebuf_get((target), (blkno), (len), PBF_READ | (flags))
-#define xfs_buf_get_flags(target, blkno, len, flags) \
-		pagebuf_get((target), (blkno), (len), (flags))
-
 static inline int	xfs_bawrite(void *mp, xfs_buf_t *bp)
 {
 	bp->pb_fspriv3 = mp;
@@ -508,10 +512,6 @@ static inline void	xfs_buf_relse(xfs_buf_t *bp)
 #define xfs_biodone(pb)		    \
 	    pagebuf_iodone(pb, (pb->pb_flags & PBF_FS_DATAIOD), 0)
 
-#define xfs_incore(buftarg,blkno,len,lockit) \
-	    pagebuf_find(buftarg, blkno ,len, lockit)
-
-
 #define xfs_biomove(pb, off, len, data, rw) \
 	    pagebuf_iomove((pb), (off), (len), (data), \
 		((rw) == XFS_B_WRITE) ? PBRW_WRITE : PBRW_READ)