diff options
| -rw-r--r-- | fs/qnx4/inode.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c index 7900a813d90f..552e994e3aa1 100644 --- a/fs/qnx4/inode.c +++ b/fs/qnx4/inode.c @@ -66,23 +66,31 @@ static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_h 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 @@ unsigned long qnx4_block_map( struct inode *inode, long iblock ) 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; |