LU-9771 flr: read support for flr

[fs/lustre-release.git] / lustre / llite / file.c

diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index 7f43784..542a026 100644 (file)
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -1126,6 +1126,10 @@ static void ll_io_init(struct cl_io *io, struct file *file, enum cl_io_type iot)
                io->ci_pio = !io->u.ci_rw.rw_append;
        else
                io->ci_pio = 0;
+
+       /* FLR: only use non-delay I/O for read as there is only one
+        * avaliable mirror for write. */
+       io->ci_ndelay = !(iot == CIT_WRITE);
 }
 
 static int ll_file_io_ptask(struct cfs_ptask *ptask)
@@ -1139,16 +1143,15 @@ static int ll_file_io_ptask(struct cfs_ptask *ptask)
        __u16 refcheck;
        ENTRY;
 
-       env = cl_env_get(&refcheck);
-       if (IS_ERR(env))
-               RETURN(PTR_ERR(env));
-
        CDEBUG(D_VFSTRACE, "%s: %s range: [%llu, %llu)\n",
                file_dentry(file)->d_name.name,
                pt->cip_iot == CIT_READ ? "read" : "write",
                pos, pos + pt->cip_count);
 
-restart:
+       env = cl_env_get(&refcheck);
+       if (IS_ERR(env))
+               RETURN(PTR_ERR(env));
+
        io = vvp_env_thread_io(env);
        ll_io_init(io, file, pt->cip_iot);
        io->u.ci_rw.rw_iter = pt->cip_iter;
@@ -1190,25 +1193,15 @@ restart:
        }
 
        cl_io_fini(env, io);
+       cl_env_put(env, &refcheck);
 
-       if ((rc == 0 || rc == -ENODATA) &&
-           pt->cip_result < pt->cip_count &&
-           io->ci_need_restart) {
-               CDEBUG(D_VFSTRACE,
-                       "%s: restart %s range: [%llu, %llu) ret: %zd, rc: %d\n",
-                       file_dentry(file)->d_name.name,
-                       pt->cip_iot == CIT_READ ? "read" : "write",
-                       pos, pos + pt->cip_count - pt->cip_result,
-                       pt->cip_result, rc);
-               goto restart;
-       }
+       pt->cip_need_restart = io->ci_need_restart;
 
        CDEBUG(D_VFSTRACE, "%s: %s ret: %zd, rc: %d\n",
                file_dentry(file)->d_name.name,
                pt->cip_iot == CIT_READ ? "read" : "write",
                pt->cip_result, rc);
 
-       cl_env_put(env, &refcheck);
        RETURN(pt->cip_result > 0 ? 0 : rc);
 }
 
@@ -1226,6 +1219,8 @@ ll_file_io_generic(const struct lu_env *env, struct vvp_io_args *args,
        loff_t                  pos = *ppos;
        ssize_t                 result = 0;
        int                     rc = 0;
+       unsigned                retried = 0;
+       bool                    restarted = false;
 
        ENTRY;
 
@@ -1239,9 +1234,10 @@ restart:
        if (args->via_io_subtype == IO_NORMAL) {
                io->u.ci_rw.rw_iter = *args->u.normal.via_iter;
                io->u.ci_rw.rw_iocb = *args->u.normal.via_iocb;
-       } else {
-               io->ci_pio = 0;
        }
+       if (args->via_io_subtype != IO_NORMAL || restarted)
+               io->ci_pio = 0;
+       io->ci_ndelay_tried = retried;
 
        if (cl_io_rw_init(env, io, iot, pos, count) == 0) {
                bool range_locked = false;
@@ -1324,12 +1320,20 @@ restart:
 out:
        cl_io_fini(env, io);
 
+       CDEBUG(D_VFSTRACE,
+              "%s: %d io complete with rc: %d, result: %zd, restart: %d\n",
+              file->f_path.dentry->d_name.name,
+              iot, rc, result, io->ci_need_restart);
+
        if ((rc == 0 || rc == -ENODATA) && count > 0 && io->ci_need_restart) {
                CDEBUG(D_VFSTRACE,
                        "%s: restart %s range: [%llu, %llu) ret: %zd, rc: %d\n",
                        file_dentry(file)->d_name.name,
                        iot == CIT_READ ? "read" : "write",
                        pos, pos + count, result, rc);
+               /* preserve the tried count for FLR */
+               retried = io->ci_ndelay_tried;
+               restarted = true;
                goto restart;
        }