f2fs: introduce f2fs_bmap_compress()

to support bmap() on compressed inode: if queried block locates in
non-compressed cluster, return its physical block address.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b79d643..ff8a92d 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3666,6 +3666,37 @@ static int f2fs_set_data_page_dirty(struct page *page)
        return 0;
 }
 
+
+static sector_t f2fs_bmap_compress(struct inode *inode, sector_t block)
+{
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+       struct dnode_of_data dn;
+       sector_t start_idx, blknr = 0;
+       int ret;
+
+       start_idx = round_down(block, F2FS_I(inode)->i_cluster_size);
+
+       set_new_dnode(&dn, inode, NULL, NULL, 0);
+       ret = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
+       if (ret)
+               return 0;
+
+       if (dn.data_blkaddr != COMPRESS_ADDR) {
+               dn.ofs_in_node += block - start_idx;
+               blknr = f2fs_data_blkaddr(&dn);
+               if (!__is_valid_data_blkaddr(blknr))
+                       blknr = 0;
+       }
+
+       f2fs_put_dnode(&dn);
+
+       return blknr;
+#else
+       return -EOPNOTSUPP;
+#endif
+}
+
+
 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
 {
        struct inode *inode = mapping->host;
@@ -3677,6 +3708,9 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
        if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
                filemap_write_and_wait(mapping);
 
+       if (f2fs_compressed_file(inode))
+               return f2fs_bmap_compress(inode, block);
+
        return generic_block_bmap(mapping, block, get_data_block_bmap);
 }