qnx4: new helper - try_extent()
checking if an extent is the one we are looking for is done twice
in qnx4_block_map(); gather that code into a helper function.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index 7900a81..552e994 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -66,23 +66,31 @@
return 0;
}
+static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset)
+{
+ u32 size = le32_to_cpu(extent->xtnt_size);
+ if (*offset < size)
+ return le32_to_cpu(extent->xtnt_blk) + *offset - 1;
+ *offset -= size;
+ return 0;
+}
+
unsigned long qnx4_block_map( struct inode *inode, long iblock )
{
int ix;
- long offset, i_xblk;
- unsigned long block = 0;
+ long i_xblk;
struct buffer_head *bh = NULL;
struct qnx4_xblk *xblk = NULL;
struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);
u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);
+ u32 offset = iblock;
+ u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);
- if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) {
+ if (block) {
// iblock is in the first extent. This is easy.
- block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1;
} else {
// iblock is beyond first extent. We have to follow the extent chain.
i_xblk = le32_to_cpu(qnx4_inode->di_xblk);
- offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size);
ix = 0;
while ( --nxtnt > 0 ) {
if ( ix == 0 ) {
@@ -98,12 +106,11 @@
return -EIO;
}
}
- if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) {
+ block = try_extent(&xblk->xblk_xtnts[ix], &offset);
+ if (block) {
// got it!
- block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1;
break;
}
- offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size);
if ( ++ix >= xblk->xblk_num_xtnts ) {
i_xblk = le32_to_cpu(xblk->xblk_next_xblk);
ix = 0;