virtiofs-beegfs.diff

diff --git a/fs/dax.c b/fs/dax.c
index 435f5b6..3a3be7d 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -976,8 +976,10 @@ int dax_writeback_mapping_range(struct address_space *mapping,
 	int ret = 0;
 	unsigned int scanned = 0;
 
-	if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
+	/*if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
+		printk("WARN_ON_ONCE() %i %i", inode->i_blkbits, PAGE_SHIFT);
 		return -EIO;
+	*/
 
 	if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
 		return 0;
 
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 794c551..f5ba426 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2722,9 +2722,13 @@ static int fuse_dax_writepages(struct address_space *mapping,
 
 	struct inode *inode = mapping->host;
 	struct fuse_conn *fc = get_fuse_conn(inode);
+        int ret = 0;
 
-	return dax_writeback_mapping_range(mapping,
+	ret = dax_writeback_mapping_range(mapping,
 		NULL, fc->dax_dev, wbc);
+	if (ret)
+		printk("dax_writeback_mapping_range() failed. err=%d", ret);
+	return ret;
 }
 
 static int fuse_writepages(struct address_space *mapping,
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 4871933..a63a8dd 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1032,7 +1032,7 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 					max_t(unsigned int, arg->max_pages, 1));
 			}
 			if ((arg->flags & FUSE_MAP_ALIGNMENT) &&
-			    (FUSE_DAX_MEM_RANGE_SZ % arg->map_alignment)) {
+			    (FUSE_DAX_MEM_RANGE_SZ % (1UL << arg->map_alignment))) {
 				printk(KERN_ERR "FUSE: map_alignment %u incompatible with dax mem range size %u\n",
 				       arg->map_alignment,
 				       FUSE_DAX_MEM_RANGE_SZ);
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index ac23f57..dd6a382 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -274,7 +274,7 @@ struct fuse_file_lock {
  * FUSE_CACHE_SYMLINKS: cache READLINK responses
  * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
  * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
- * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains byte alignment for
+ * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
  *		       foffset and moffset fields in struct
  *		       fuse_setupmapping_out and fuse_removemapping_one.
  */
@@ -658,9 +658,8 @@ struct fuse_init_out {
 	uint32_t	max_write;
 	uint32_t	time_gran;
 	uint16_t	max_pages;
-	uint16_t	padding;
-	uint32_t	map_alignment;
-	uint32_t	unused[7];
+	uint16_t        map_alignment;
+	uint32_t        unused[8];
 };
 
 #define CUSE_INIT_INFO_MAX 4096