f2fs: fix remove page failed in invalidate compress pages

Since compress inode not a regular file, generic_error_remove_page in
f2fs_invalidate_compress_pages will always be failed, set compress
inode as a regular file to fix it.

Fixes: 6ce19af ("f2fs: compress: add compress_inode to cache compressed blocks")
Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: Fengnan Chang

fs/f2fs/inode.c

@@ -516,6 +516,11 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
 	} else if (ino == F2FS_COMPRESS_INO(sbi)) {
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 		inode->i_mapping->a_ops = &f2fs_compress_aops;
+		/*
+		 * generic_error_remove_page only truncates pages of regular
+		 * inode
+		 */
+		inode->i_mode |= S_IFREG;
 #endif
 		mapping_set_gfp_mask(inode->i_mapping,
 			GFP_NOFS | __GFP_HIGHMEM | __GFP_MOVABLE);