@@ -171,6 +171,7 @@ struct lo_data {
int allow_direct_io;
int announce_submounts;
int perfile_dax_cap; /* capability of backend fs */
+ bool perfile_dax; /* enable per-file DAX or not */
bool use_statx;
struct lo_inode root;
GHashTable *inodes; /* protected by lo->mutex */
@@ -716,6 +717,10 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn)
if (conn->capable & FUSE_CAP_PERFILE_DAX && lo->perfile_dax_cap ) {
conn->want |= FUSE_CAP_PERFILE_DAX;
+ lo->perfile_dax = 1;
+ }
+ else {
+ lo->perfile_dax = 0;
}
}
@@ -983,6 +988,41 @@ static int do_statx(struct lo_data *lo, int dirfd, const char *pathname,
return 0;
}
+/*
+ * If the file is marked with FS_DAX_FL or FS_XFLAG_DAX, then DAX should be
+ * enabled for this file.
+ */
+static bool lo_should_enable_dax(struct lo_data *lo, struct lo_inode *dir,
+ const char *name)
+{
+ int res, fd;
+ int ret = false;;
+ unsigned int attr;
+ struct fsxattr xattr;
+
+ if (!lo->perfile_dax)
+ return false;
+
+ /* Open file without O_PATH, so that ioctl can be called. */
+ fd = openat(dir->fd, name, O_NOFOLLOW);
+ if (fd == -1)
+ return false;
+
+ if (lo->perfile_dax_cap == DAX_FLAG_FLAGS) {
+ res = ioctl(fd, FS_IOC_GETFLAGS, &attr);
+ if (!res && (attr & FS_DAX_FL))
+ ret = true;
+ }
+ else if (lo->perfile_dax_cap == DAX_FLAG_XATTR) {
+ res = ioctl(fd, FS_IOC_FSGETXATTR, &xattr);
+ if (!res && (xattr.fsx_xflags & FS_XFLAG_DAX))
+ ret = true;
+ }
+
+ close(fd);
+ return ret;
+}
+
/*
* Increments nlookup on the inode on success. unref_inode_lolocked() must be
* called eventually to decrement nlookup again. If inodep is non-NULL, the
@@ -1038,6 +1078,9 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
e->attr_flags |= FUSE_ATTR_SUBMOUNT;
}
+ if (lo_should_enable_dax(lo, dir, name))
+ e->attr_flags |= FUSE_ATTR_DAX;
+
inode = lo_find(lo, &e->attr, mnt_id);
if (inode) {
close(newfd);
For passthrough, when the corresponding virtiofs in guest is mounted with '-o dax=inode', advertise that the file is capable of per-file DAX if the inode in the backend fs is marked with FS_DAX_FL flag. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> --- tools/virtiofsd/passthrough_ll.c | 43 ++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+)