[PATCH 02/10] xfs: refactor xfs_buf_item_format_segment

Christoph Hellwig
2013-11-29T08:40:05Z

[-- Attachment #1: 0002-xfs-refactor-xfs_buf_item_format_segment.patch --]
[-- Type: text/plain, Size: 3829 bytes --]

Add two helpers to make the code more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_buf_item.c | 72 ++++++++++++++++++++++++++-----------------------
1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index a64f67b..a30c1fb 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -182,6 +182,34 @@ xfs_buf_item_size(
trace_xfs_buf_item_size(bip);
}

+static inline struct xfs_log_iovec *
+xfs_buf_item_copy_iovec(
+ struct xfs_log_iovec *vecp,
+ struct xfs_buf *bp,
+ uint offset,
+ int first_bit,
+ uint nbits)
+{
+ offset += first_bit * XFS_BLF_CHUNK;
+
+ vecp->i_type = XLOG_REG_TYPE_BCHUNK;
+ vecp->i_addr = xfs_buf_offset(bp, offset);
+ vecp->i_len = nbits * XFS_BLF_CHUNK;
+ return vecp + 1;
+}
+
+static inline bool
+xfs_buf_item_straddle(
+ struct xfs_buf *bp,
+ uint offset,
+ int next_bit,
+ int last_bit)
+{
+ return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) !=
+ (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) +
+ XFS_BLF_CHUNK);
+}
+
static struct xfs_log_iovec *
xfs_buf_item_format_segment(
struct xfs_buf_log_item *bip,
@@ -196,7 +224,6 @@ xfs_buf_item_format_segment(
int last_bit;
int next_bit;
uint nbits;
- uint buffer_offset;

/* copy the flags across from the base format item */
blfp->blf_flags = bip->__bli_format.blf_flags;
@@ -239,7 +266,6 @@ xfs_buf_item_format_segment(
/*
* Fill in an iovec for each set of contiguous chunks.
*/
-
last_bit = first_bit;
nbits = 1;
for (;;) {
@@ -252,42 +278,22 @@ xfs_buf_item_format_segment(
next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
(uint)last_bit + 1);
/*
- * If we run out of bits fill in the last iovec and get
- * out of the loop.
- * Else if we start a new set of bits then fill in the
- * iovec for the series we were looking at and start
- * counting the bits in the new one.
- * Else we're still in the same set of bits so just
- * keep counting and scanning.
+ * If we run out of bits fill in the last iovec and get out of
+ * the loop. Else if we start a new set of bits then fill in
+ * the iovec for the series we were looking at and start
+ * counting the bits in the new one. Else we're still in the
+ * same set of bits so just keep counting and scanning.
*/
if (next_bit == -1) {
- buffer_offset = offset + first_bit * XFS_BLF_CHUNK;
- vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLF_CHUNK;
- vecp->i_type = XLOG_REG_TYPE_BCHUNK;
+ xfs_buf_item_copy_iovec(vecp, bp, offset,
+ first_bit, nbits);
nvecs++;
break;
- } else if (next_bit != last_bit + 1) {
- buffer_offset = offset + first_bit * XFS_BLF_CHUNK;
- vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLF_CHUNK;
- vecp->i_type = XLOG_REG_TYPE_BCHUNK;
- nvecs++;
- vecp++;
- first_bit = next_bit;
- last_bit = next_bit;
- nbits = 1;
- } else if (xfs_buf_offset(bp, offset +
- (next_bit << XFS_BLF_SHIFT)) !=
- (xfs_buf_offset(bp, offset +
- (last_bit << XFS_BLF_SHIFT)) +
- XFS_BLF_CHUNK)) {
- buffer_offset = offset + first_bit * XFS_BLF_CHUNK;
- vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLF_CHUNK;
- vecp->i_type = XLOG_REG_TYPE_BCHUNK;
+ } else if (next_bit != last_bit + 1 ||
+ xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) {
+ vecp = xfs_buf_item_copy_iovec(vecp, bp, offset,
+ first_bit, nbits);
nvecs++;
- vecp++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
--
1.7.10.4