xfs: refactor xfs_buf_item_format_segment

Add two helpers to make the code more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 39 insertions, 33 deletions

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index a64f67ba25d3..a30c1fb1bec6 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;