LU-12328 flr: avoid reading unhealthy mirror

[fs/lustre-release.git] / lustre / osc / osc_io.c

diff --git a/lustre/osc/osc_io.c b/lustre/osc/osc_io.c
index b4a196f..03c0e50 100644 (file)
--- a/lustre/osc/osc_io.c
+++ b/lustre/osc/osc_io.c
@@ -368,15 +368,30 @@ int osc_io_commit_async(const struct lu_env *env,
 }
 EXPORT_SYMBOL(osc_io_commit_async);
 
+static bool osc_import_not_healthy(struct obd_import *imp)
+{
+       return imp->imp_invalid || imp->imp_deactive ||
+              !(imp->imp_state == LUSTRE_IMP_FULL ||
+                imp->imp_state == LUSTRE_IMP_IDLE);
+}
+
 int osc_io_iter_init(const struct lu_env *env, const struct cl_io_slice *ios)
 {
        struct osc_object *osc = cl2osc(ios->cis_obj);
        struct obd_import *imp = osc_cli(osc)->cl_import;
        struct osc_io *oio = osc_env_io(env);
        int rc = -EIO;
+       ENTRY;
 
        spin_lock(&imp->imp_lock);
-       if (likely(!imp->imp_invalid)) {
+       /**
+        * check whether this OSC device is available for non-delay read,
+        * fast switching mirror if we haven't tried all mirrors.
+        */
+       if (ios->cis_io->ci_type == CIT_READ && ios->cis_io->ci_ndelay &&
+           !ios->cis_io->ci_tried_all_mirrors && osc_import_not_healthy(imp)) {
+               rc = -EWOULDBLOCK;
+       } else if (likely(!imp->imp_invalid)) {
                atomic_inc(&osc->oo_nr_ios);
                oio->oi_is_active = 1;
                rc = 0;
@@ -386,7 +401,7 @@ int osc_io_iter_init(const struct lu_env *env, const struct cl_io_slice *ios)
        if (cfs_capable(CFS_CAP_SYS_RESOURCE))
                oio->oi_cap_sys_resource = 1;
 
-       return rc;
+       RETURN(rc);
 }
 EXPORT_SYMBOL(osc_io_iter_init);