LU-16713 llite: writeback/commit pages under memory pressure

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

diff --git a/lustre/osc/osc_io.c b/lustre/osc/osc_io.c
index 516037c..5030427 100644 (file)
--- a/lustre/osc/osc_io.c
+++ b/lustre/osc/osc_io.c
@@ -957,15 +957,26 @@ EXPORT_SYMBOL(osc_fsync_ost);
 static int osc_io_fsync_start(const struct lu_env *env,
                              const struct cl_io_slice *slice)
 {
-       struct cl_io       *io  = slice->cis_io;
+       struct cl_io *io = slice->cis_io;
        struct cl_fsync_io *fio = &io->u.ci_fsync;
-       struct cl_object   *obj = slice->cis_obj;
-       struct osc_object  *osc = cl2osc(obj);
-       pgoff_t start  = fio->fi_start >> PAGE_SHIFT;
-       pgoff_t end    = fio->fi_end >> PAGE_SHIFT;
-       int     result = 0;
+       struct cl_object *obj = slice->cis_obj;
+       struct osc_object *osc = cl2osc(obj);
+       pgoff_t start = fio->fi_start >> PAGE_SHIFT;
+       pgoff_t end = fio->fi_end >> PAGE_SHIFT;
+       int result = 0;
+
        ENTRY;
 
+       if (fio->fi_mode == CL_FSYNC_RECLAIM) {
+               struct client_obd *cli = osc_cli(osc);
+
+               if (!atomic_long_read(&cli->cl_unstable_count)) {
+                       /* Stop flush when there are no unstable pages? */
+                       CDEBUG(D_CACHE, "unstable count is zero\n");
+                       RETURN(0);
+               }
+       }
+
        if (fio->fi_end == OBD_OBJECT_EOF)
                end = CL_PAGE_EOF;
 
@@ -982,20 +993,30 @@ static int osc_io_fsync_start(const struct lu_env *env,
                fio->fi_nr_written += result;
                result = 0;
        }
-       if (fio->fi_mode == CL_FSYNC_ALL) {
+       if (fio->fi_mode == CL_FSYNC_ALL || fio->fi_mode == CL_FSYNC_RECLAIM) {
+               struct osc_io *oio = cl2osc_io(env, slice);
+               struct osc_async_cbargs *cbargs = &oio->oi_cbarg;
                int rc;
 
                /* we have to wait for writeback to finish before we can
                 * send OST_SYNC RPC. This is bad because it causes extents
                 * to be written osc by osc. However, we usually start
                 * writeback before CL_FSYNC_ALL so this won't have any real
-                * problem. */
-               rc = osc_cache_wait_range(env, osc, start, end);
-               if (result == 0)
-                       result = rc;
+                * problem.
+                * We do not have to wait for waitback to finish in the memory
+                * reclaim environment.
+                */
+               if (fio->fi_mode == CL_FSYNC_ALL) {
+                       rc = osc_cache_wait_range(env, osc, start, end);
+                       if (result == 0)
+                               result = rc;
+               }
+
                rc = osc_fsync_ost(env, osc, fio);
-               if (result == 0)
+               if (result == 0) {
+                       cbargs->opc_rpc_sent = 1;
                        result = rc;
+               }
        }
 
        RETURN(result);
@@ -1005,16 +1026,17 @@ void osc_io_fsync_end(const struct lu_env *env,
                      const struct cl_io_slice *slice)
 {
        struct cl_fsync_io *fio = &slice->cis_io->u.ci_fsync;
-       struct cl_object   *obj = slice->cis_obj;
+       struct cl_object *obj = slice->cis_obj;
+       struct osc_io *oio = cl2osc_io(env, slice);
+       struct osc_async_cbargs *cbargs = &oio->oi_cbarg;
        pgoff_t start = fio->fi_start >> PAGE_SHIFT;
        pgoff_t end   = fio->fi_end >> PAGE_SHIFT;
        int result = 0;
 
        if (fio->fi_mode == CL_FSYNC_LOCAL) {
                result = osc_cache_wait_range(env, cl2osc(obj), start, end);
-       } else if (fio->fi_mode == CL_FSYNC_ALL) {
-               struct osc_io           *oio    = cl2osc_io(env, slice);
-               struct osc_async_cbargs *cbargs = &oio->oi_cbarg;
+       } else if (cbargs->opc_rpc_sent && (fio->fi_mode == CL_FSYNC_ALL ||
+                                           fio->fi_mode == CL_FSYNC_RECLAIM)) {
 
                wait_for_completion(&cbargs->opc_sync);
                if (result == 0)