[PATCH v3] staging: erofs: support bmap

[Chao Yu]

Add erofs_bmap() to support FIBMAP ioctl on flatmode inode.

Reviewed-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v3:
- use erofs_blk_t instead of unsigned int.
- simply judgment condition.
 drivers/staging/erofs/data.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index cc31c3e5984c..f73e4720cd3e 100644
--- a/drivers/staging/erofs/data.c
+++ b/drivers/staging/erofs/data.c
@@ -392,9 +392,42 @@ static int erofs_raw_access_readpages(struct file *filp,
 	return 0;
 }
 
+static int erofs_get_block(struct inode *inode, sector_t iblock,
+			   struct buffer_head *bh, int create)
+{
+	struct erofs_map_blocks map = {
+		.m_la = iblock << 9,
+	};
+	int err;
+
+	err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+	if (err)
+		return err;
+
+	if (map.m_flags & EROFS_MAP_MAPPED)
+		bh->b_blocknr = erofs_blknr(map.m_pa);
+
+	return err;
+}
+
+static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *inode = mapping->host;
+
+	if (is_inode_flat_inline(inode)) {
+		erofs_blk_t blks = i_size_read(inode) >> LOG_BLOCK_SIZE;
+
+		if (block >> LOG_SECTORS_PER_BLOCK >= blks)
+			return 0;
+	}
+
+	return generic_block_bmap(mapping, block, erofs_get_block);
+}
+
 /* for uncompressed (aligned) files and raw access for other files */
 const struct address_space_operations erofs_raw_access_aops = {
 	.readpage = erofs_raw_access_readpage,
 	.readpages = erofs_raw_access_readpages,
+	.bmap = erofs_bmap,
 };
 
-- 
2.18.0.rc1