LU-9771 flr: read support for flr

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

diff --git a/lustre/llite/vvp_io.c b/lustre/llite/vvp_io.c
index 886b816..c9c19b5 100644 (file)
--- a/lustre/llite/vvp_io.c
+++ b/lustre/llite/vvp_io.c
@@ -298,7 +298,9 @@ static void vvp_io_fini(const struct lu_env *env, const struct cl_io_slice *ios)
        struct cl_object *obj = io->ci_obj;
        struct vvp_io    *vio = cl2vvp_io(env, ios);
        struct inode     *inode = vvp_object_inode(obj);
+       __u32             gen = 0;
        int rc;
+       ENTRY;
 
        CLOBINVRNT(env, obj, vvp_object_invariant(obj));
 
@@ -320,18 +322,40 @@ static void vvp_io_fini(const struct lu_env *env, const struct cl_io_slice *ios)
                 * block on layout lock held by the MDT
                 * as MDT will not send new layout in lvb (see LU-3124)
                 * we have to explicitly fetch it, all this will be done
-                * by ll_layout_refresh()
+                * by ll_layout_refresh().
+                * Even if ll_layout_restore() returns zero, it doesn't mean
+                * that restore has been successful. Therefore it sets
+                * ci_verify_layout so that it will check layout at the end
+                * of this function.
                 */
-               if (rc == 0) {
-                       io->ci_restore_needed = 0;
-                       io->ci_need_restart = 1;
-                       io->ci_verify_layout = 1;
-               } else {
+               if (rc) {
                        io->ci_restore_needed = 1;
                        io->ci_need_restart = 0;
                        io->ci_verify_layout = 0;
                        io->ci_result = rc;
+                       GOTO(out, rc);
                }
+
+               io->ci_restore_needed = 0;
+
+               /* Even if ll_layout_restore() returns zero, it doesn't mean
+                * that restore has been successful. Therefore it should verify
+                * if there was layout change and restart I/O correspondingly.
+                */
+               ll_layout_refresh(inode, &gen);
+               io->ci_need_restart = vio->vui_layout_gen != gen;
+               if (io->ci_need_restart) {
+                       CDEBUG(D_VFSTRACE,
+                              DFID" layout changed from %d to %d.\n",
+                              PFID(lu_object_fid(&obj->co_lu)),
+                              vio->vui_layout_gen, gen);
+                       /* today successful restore is the only possible
+                        * case */
+                       /* restore was done, clear restoring state */
+                       ll_file_clear_flag(ll_i2info(vvp_object_inode(obj)),
+                                          LLIF_FILE_RESTORING);
+               }
+               GOTO(out, 0);
        }
 
        /**
@@ -368,11 +392,11 @@ static void vvp_io_fini(const struct lu_env *env, const struct cl_io_slice *ios)
                io->ci_result = rc;
                if (!rc)
                        io->ci_need_restart = 1;
+               GOTO(out, rc);
        }
 
-       if (!io->ci_ignore_layout && io->ci_verify_layout) {
-               __u32 gen = 0;
-
+       if (!io->ci_need_restart &&
+           !io->ci_ignore_layout && io->ci_verify_layout) {
                /* check layout version */
                ll_layout_refresh(inode, &gen);
                io->ci_need_restart = vio->vui_layout_gen != gen;
@@ -381,13 +405,11 @@ static void vvp_io_fini(const struct lu_env *env, const struct cl_io_slice *ios)
                               DFID" layout changed from %d to %d.\n",
                               PFID(lu_object_fid(&obj->co_lu)),
                               vio->vui_layout_gen, gen);
-                       /* today successful restore is the only possible
-                        * case */
-                       /* restore was done, clear restoring state */
-                       ll_file_clear_flag(ll_i2info(vvp_object_inode(obj)),
-                                          LLIF_FILE_RESTORING);
                }
+               GOTO(out, 0);
        }
+out:
+       EXIT;
 }
 
 static void vvp_io_fault_fini(const struct lu_env *env,
@@ -755,6 +777,7 @@ static int vvp_io_read_start(const struct lu_env *env,
        size_t tot = vio->vui_tot_count;
        int exceed = 0;
        int result;
+       ENTRY;
 
        CLOBINVRNT(env, obj, vvp_object_invariant(obj));
 
@@ -766,13 +789,16 @@ static int vvp_io_read_start(const struct lu_env *env,
                down_read(&lli->lli_trunc_sem);
 
        if (!can_populate_pages(env, io, inode))
-               return 0;
+               RETURN(0);
 
-       result = vvp_prep_size(env, obj, io, range->cir_pos, tot, &exceed);
+       /* Unless this is reading a sparse file, otherwise the lock has already
+        * been acquired so vvp_prep_size() is an empty op. */
+       result = vvp_prep_size(env, obj, io, range->cir_pos, range->cir_count,
+                               &exceed);
        if (result != 0)
-               return result;
+               RETURN(result);
        else if (exceed != 0)
-               goto out;
+               GOTO(out, result);
 
        LU_OBJECT_HEADER(D_INODE, env, &obj->co_lu,
                         "Read ino %lu, %lu bytes, offset %lld, size %llu\n",
@@ -815,6 +841,7 @@ static int vvp_io_read_start(const struct lu_env *env,
                CERROR("Wrong IO type %u\n", vio->vui_io_subtype);
                LBUG();
        }
+       GOTO(out, result);
 
 out:
        if (result >= 0) {