An example implementation of supporting per-file DAX flag for virtiofsd,
where DAx is enabled for files larger than 1M size.
Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
contrib/virtiofsd/fuse_kernel.h | 4 +++-
contrib/virtiofsd/fuse_lowlevel.c | 3 +++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/contrib/virtiofsd/fuse_kernel.h b/contrib/virtiofsd/fuse_kernel.h
index d2b7ccf96b..9c476b7021 100644
--- a/contrib/virtiofsd/fuse_kernel.h
+++ b/contrib/virtiofsd/fuse_kernel.h
@@ -165,6 +165,8 @@
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
+#define FUSE_ATTR_DAX (1 << 1)
+
/* Make sure all structures are padded to 64bit boundary, so 32bit
userspace works under 64bit kernels */
@@ -184,7 +186,7 @@ struct fuse_attr {
uint32_t gid;
uint32_t rdev;
uint32_t blksize;
- uint32_t padding;
+ uint32_t flags;
};
struct fuse_kstatfs {
diff --git a/contrib/virtiofsd/fuse_lowlevel.c b/contrib/virtiofsd/fuse_lowlevel.c
index 046a1b4a02..d8a3873246 100644
--- a/contrib/virtiofsd/fuse_lowlevel.c
+++ b/contrib/virtiofsd/fuse_lowlevel.c
@@ -60,6 +60,9 @@ static void convert_stat(const struct stat *stbuf, struct fuse_attr *attr)
attr->atimensec = ST_ATIM_NSEC(stbuf);
attr->mtimensec = ST_MTIM_NSEC(stbuf);
attr->ctimensec = ST_CTIM_NSEC(stbuf);
+
+ if (stbuf->st_size >= 1048576)
+ attr->flags |= FUSE_ATTR_DAX;
}
static void convert_attr(const struct fuse_setattr_in *attr, struct stat *stbuf)
--
2.27.0
