LU-10810 osd: implement lseek method in OSD

[fs/lustre-release.git] / lustre / osd-zfs / osd_io.c

diff --git a/lustre/osd-zfs/osd_io.c b/lustre/osd-zfs/osd_io.c
index b270228..063607f 100644 (file)
--- a/lustre/osd-zfs/osd_io.c
+++ b/lustre/osd-zfs/osd_io.c
@@ -1177,6 +1177,50 @@ static int osd_declare_fallocate(const struct lu_env *env,
        RETURN(rc);
 }
 
+static loff_t osd_lseek(const struct lu_env *env, struct dt_object *dt,
+                       loff_t offset, int whence)
+{
+       struct osd_object *obj = osd_dt_obj(dt);
+       uint64_t size = obj->oo_attr.la_size;
+       uint64_t result = offset;
+       int rc;
+       boolean_t hole = whence == SEEK_HOLE;
+
+       ENTRY;
+
+       LASSERT(dt_object_exists(dt));
+       LASSERT(osd_invariant(obj));
+
+       if (offset < 0 || offset >= size)
+               RETURN(-ENXIO);
+
+#ifdef HAVE_DMU_OFFSET_NEXT
+       rc = dmu_offset_next(osd_obj2dev(obj)->od_os, obj->oo_dn->dn_object,
+                            hole, &result);
+       if (rc == ESRCH)
+               RETURN(-ENXIO);
+#else
+       /*
+        * In absence of dmu_offset_next() just do nothing but
+        * return EBUSY as does dmu_offset_next() and that means
+        * generic approach should be used.
+        */
+       rc = EBUSY;
+#endif
+       /* file was dirty, so fall back to using generic logic */
+       if (rc == EBUSY && hole)
+               RETURN(-ENXIO); /* see comment below */
+
+       /* when result is out of file range then it must be virtual hole
+        * at the end of file, but this is not real file end, so return
+        * just -ENXIO and LOV will translate it properly.
+        */
+       if (result >= size)
+               RETURN(-ENXIO);
+
+       RETURN(result);
+}
+
 struct dt_body_operations osd_body_ops = {
        .dbo_read                       = osd_read,
        .dbo_declare_write              = osd_declare_write,
@@ -1192,6 +1236,7 @@ struct dt_body_operations osd_body_ops = {
        .dbo_ladvise                    = osd_ladvise,
        .dbo_declare_fallocate          = osd_declare_fallocate,
        .dbo_fallocate                  = osd_fallocate,
+       .dbo_lseek                      = osd_lseek,
 };
 
 struct dt_body_operations osd_body_scrub_ops = {