nilfs2: support contiguous lookup of blocks

Although get_block() callback function can return extent of contiguous
blocks with bh->b_size, nilfs_get_block() function did not support
this feature.

This adds contiguous lookup feature to the block mapping codes of
nilfs, and allows the nilfs_get_blocks() function to return the extent
information by applying the feature.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index f25fd4b..2696d6b 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -43,22 +43,23 @@
  *
  * This function does not issue actual read request of the specified data
  * block. It is done by VFS.
- * Bulk read for direct-io is not supported yet. (should be supported)
  */
 int nilfs_get_block(struct inode *inode, sector_t blkoff,
 		    struct buffer_head *bh_result, int create)
 {
 	struct nilfs_inode_info *ii = NILFS_I(inode);
-	unsigned long blknum = 0;
+	__u64 blknum = 0;
 	int err = 0, ret;
 	struct inode *dat = nilfs_dat_inode(NILFS_I_NILFS(inode));
+	unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
 
-	/* This exclusion control is a workaround; should be revised */
-	down_read(&NILFS_MDT(dat)->mi_sem);	/* XXX */
-	ret = nilfs_bmap_lookup(ii->i_bmap, (unsigned long)blkoff, &blknum);
-	up_read(&NILFS_MDT(dat)->mi_sem);	/* XXX */
-	if (ret == 0) {	/* found */
+	down_read(&NILFS_MDT(dat)->mi_sem);
+	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
+	up_read(&NILFS_MDT(dat)->mi_sem);
+	if (ret >= 0) {	/* found */
 		map_bh(bh_result, inode->i_sb, blknum);
+		if (ret > 0)
+			bh_result->b_size = (ret << inode->i_blkbits);
 		goto out;
 	}
 	/* data block was not found */