staging: erofs: support bmap

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

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190716093256.108791-1-yuchao0@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index cc31c3e5984c90081c428439e6ce7bc76bc1acfd..f73e4720cd3e54802161d14d2ec4a27e014f70af 100644 (file)
--- 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,
 };