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LU-6684 lfsck: set the lfsck notify as interruptable
[fs/lustre-release.git] / lustre / lfsck / lfsck_lib.c
index 3cf9703..139c95b 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2013, 2014, Intel Corporation.
+ * Copyright (c) 2013, 2015, Intel Corporation.
  */
 /*
  * lustre/lfsck/lfsck_lib.c
@@ -30,6 +30,8 @@
 
 #define DEBUG_SUBSYSTEM S_LFSCK
 
+#include <linux/kthread.h>
+#include <linux/sched.h>
 #include <libcfs/list.h>
 #include <lu_object.h>
 #include <dt_object.h>
@@ -148,7 +150,7 @@ static void lfsck_tgt_descs_fini(struct lfsck_tgt_descs *ltds)
        }
 
        cfs_foreach_bit(ltds->ltd_tgts_bitmap, idx) {
-               ltd = LTD_TGT(ltds, idx);
+               ltd = lfsck_ltd2tgt(ltds, idx);
                if (likely(ltd != NULL)) {
                        LASSERT(list_empty(&ltd->ltd_layout_list));
                        LASSERT(list_empty(&ltd->ltd_layout_phase_list));
@@ -157,7 +159,7 @@ static void lfsck_tgt_descs_fini(struct lfsck_tgt_descs *ltds)
 
                        ltds->ltd_tgtnr--;
                        cfs_bitmap_clear(ltds->ltd_tgts_bitmap, idx);
-                       LTD_TGT(ltds, idx) = NULL;
+                       lfsck_assign_tgt(ltds, NULL, idx);
                        lfsck_tgt_put(ltd);
                }
        }
@@ -229,7 +231,7 @@ static int __lfsck_add_target(const struct lu_env *env,
                        GOTO(unlock, rc = -ENOMEM);
        }
 
-       LTD_TGT(ltds, index) = ltd;
+       lfsck_assign_tgt(ltds, ltd, index);
        cfs_bitmap_set(ltds->ltd_tgts_bitmap, index);
        ltds->ltd_tgtnr++;
 
@@ -361,29 +363,14 @@ int lfsck_fid_alloc(const struct lu_env *env, struct lfsck_instance *lfsck,
        RETURN(rc);
 }
 
-/**
- * Request the specified ibits lock for the given object.
- *
- * Before the LFSCK modifying on the namespace visible object,
- * it needs to acquire related ibits ldlm lock.
- *
- * \param[in] env      pointer to the thread context
- * \param[in] lfsck    pointer to the lfsck instance
- * \param[in] obj      pointer to the dt_object to be locked
- * \param[out] lh      pointer to the lock handle
- * \param[in] ibits    the bits for the ldlm lock to be acquired
- * \param[in] mode     the mode for the ldlm lock to be acquired
- *
- * \retval             0 for success
- * \retval             negative error number on failure
- */
-int lfsck_ibits_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
-                    struct dt_object *obj, struct lustre_handle *lh,
-                    __u64 bits, ldlm_mode_t mode)
+static int __lfsck_ibits_lock(const struct lu_env *env,
+                             struct lfsck_instance *lfsck,
+                             struct dt_object *obj, struct ldlm_res_id *resid,
+                             struct lustre_handle *lh, __u64 bits,
+                             enum ldlm_mode mode)
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
-       ldlm_policy_data_t              *policy = &info->lti_policy;
-       struct ldlm_res_id              *resid  = &info->lti_resid;
+       union ldlm_policy_data          *policy = &info->lti_policy;
        __u64                            flags  = LDLM_FL_ATOMIC_CB;
        int                              rc;
 
@@ -391,7 +378,6 @@ int lfsck_ibits_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
 
        memset(policy, 0, sizeof(*policy));
        policy->l_inodebits.bits = bits;
-       fid_build_reg_res_name(lfsck_dto2fid(obj), resid);
        if (dt_object_remote(obj)) {
                struct ldlm_enqueue_info *einfo = &info->lti_einfo;
 
@@ -422,6 +408,34 @@ int lfsck_ibits_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
 }
 
 /**
+ * Request the specified ibits lock for the given object.
+ *
+ * Before the LFSCK modifying on the namespace visible object,
+ * it needs to acquire related ibits ldlm lock.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] lfsck    pointer to the lfsck instance
+ * \param[in] obj      pointer to the dt_object to be locked
+ * \param[out] lh      pointer to the lock handle
+ * \param[in] bits     the bits for the ldlm lock to be acquired
+ * \param[in] mode     the mode for the ldlm lock to be acquired
+ *
+ * \retval             0 for success
+ * \retval             negative error number on failure
+ */
+int lfsck_ibits_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
+                    struct dt_object *obj, struct lustre_handle *lh,
+                    __u64 bits, enum ldlm_mode mode)
+{
+       struct ldlm_res_id *resid = &lfsck_env_info(env)->lti_resid;
+
+       LASSERT(!lustre_handle_is_used(lh));
+
+       fid_build_reg_res_name(lfsck_dto2fid(obj), resid);
+       return __lfsck_ibits_lock(env, lfsck, obj, resid, lh, bits, mode);
+}
+
+/**
  * Release the the specified ibits lock.
  *
  * If the lock has been acquired before, release it
@@ -430,7 +444,7 @@ int lfsck_ibits_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
  * \param[in] lh       pointer to the lock handle
  * \param[in] mode     the mode for the ldlm lock to be released
  */
-void lfsck_ibits_unlock(struct lustre_handle *lh, ldlm_mode_t mode)
+void lfsck_ibits_unlock(struct lustre_handle *lh, enum ldlm_mode mode)
 {
        if (lustre_handle_is_used(lh)) {
                ldlm_lock_decref(lh, mode);
@@ -438,12 +452,93 @@ void lfsck_ibits_unlock(struct lustre_handle *lh, ldlm_mode_t mode)
        }
 }
 
+/**
+ * Request compound ibits locks for the given <obj, name> pairs.
+ *
+ * Before the LFSCK modifying on the namespace visible object, it needs to
+ * acquire related ibits ldlm lock. Usually, we can use lfsck_ibits_lock for
+ * the lock purpose. But the simple lfsck_ibits_lock for directory-based
+ * modificationis (such as insert name entry to the directory) may be too
+ * coarse-grained and not efficient.
+ *
+ * The lfsck_lock() will request compound ibits locks on the specified
+ * <obj, name> pairs: the PDO (Parallel Directory Operations) ibits (UPDATE)
+ * lock on the directory object, and the regular ibits lock on the name hash.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] lfsck    pointer to the lfsck instance
+ * \param[in] obj      pointer to the dt_object to be locked
+ * \param[in] name     used for building the PDO lock resource
+ * \param[out] llh     pointer to the lfsck_lock_handle
+ * \param[in] bits     the bits for the ldlm lock to be acquired
+ * \param[in] mode     the mode for the ldlm lock to be acquired
+ *
+ * \retval             0 for success
+ * \retval             negative error number on failure
+ */
+int lfsck_lock(const struct lu_env *env, struct lfsck_instance *lfsck,
+              struct dt_object *obj, const char *name,
+              struct lfsck_lock_handle *llh, __u64 bits, enum ldlm_mode mode)
+{
+       struct ldlm_res_id *resid = &lfsck_env_info(env)->lti_resid;
+       int                 rc;
+
+       LASSERT(S_ISDIR(lfsck_object_type(obj)));
+       LASSERT(name != NULL);
+       LASSERT(name[0] != 0);
+       LASSERT(!lustre_handle_is_used(&llh->llh_pdo_lh));
+       LASSERT(!lustre_handle_is_used(&llh->llh_reg_lh));
+
+       switch (mode) {
+       case LCK_EX:
+               llh->llh_pdo_mode = LCK_EX;
+               break;
+       case LCK_PW:
+               llh->llh_pdo_mode = LCK_CW;
+               break;
+       case LCK_PR:
+               llh->llh_pdo_mode = LCK_CR;
+               break;
+       default:
+               CDEBUG(D_LFSCK, "%s: unexpected PDO lock mode %u on the obj "
+                      DFID"\n", lfsck_lfsck2name(lfsck), mode,
+                      PFID(lfsck_dto2fid(obj)));
+               LBUG();
+       }
+
+       fid_build_reg_res_name(lfsck_dto2fid(obj), resid);
+       rc = __lfsck_ibits_lock(env, lfsck, obj, resid, &llh->llh_pdo_lh,
+                               MDS_INODELOCK_UPDATE, llh->llh_pdo_mode);
+       if (rc != 0)
+               return rc;
+
+       llh->llh_reg_mode = mode;
+       resid->name[LUSTRE_RES_ID_HSH_OFF] = full_name_hash(name, strlen(name));
+       LASSERT(resid->name[LUSTRE_RES_ID_HSH_OFF] != 0);
+       rc = __lfsck_ibits_lock(env, lfsck, obj, resid, &llh->llh_reg_lh,
+                               bits, llh->llh_reg_mode);
+       if (rc != 0)
+               lfsck_ibits_unlock(&llh->llh_pdo_lh, llh->llh_pdo_mode);
+
+       return rc;
+}
+
+/**
+ * Release the the compound ibits locks.
+ *
+ * \param[in] llh      pointer to the lfsck_lock_handle to be released
+ */
+void lfsck_unlock(struct lfsck_lock_handle *llh)
+{
+       lfsck_ibits_unlock(&llh->llh_reg_lh, llh->llh_reg_mode);
+       lfsck_ibits_unlock(&llh->llh_pdo_lh, llh->llh_pdo_mode);
+}
+
 int lfsck_find_mdt_idx_by_fid(const struct lu_env *env,
                              struct lfsck_instance *lfsck,
                              const struct lu_fid *fid)
 {
-       struct seq_server_site  *ss     =
-                       lu_site2seq(lfsck->li_bottom->dd_lu_dev.ld_site);
+       struct seq_server_site  *ss     = lfsck_dev_site(lfsck);
        struct lu_seq_range     *range  = &lfsck_env_info(env)->lti_range;
        int                      rc;
 
@@ -479,14 +574,14 @@ static int lfsck_lpf_remove_name_entry(const struct lu_env *env,
                                       const char *name)
 {
        struct dt_object        *parent = lfsck->li_lpf_root_obj;
-       struct dt_device        *dev    = lfsck->li_next;
+       struct dt_device        *dev    = lfsck_obj2dev(parent);
        struct thandle          *th;
-       struct lustre_handle     lh     = { 0 };
+       struct lfsck_lock_handle *llh   = &lfsck_env_info(env)->lti_llh;
        int                      rc;
        ENTRY;
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       rc = lfsck_lock(env, lfsck, parent, name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                RETURN(rc);
 
@@ -502,12 +597,11 @@ static int lfsck_lpf_remove_name_entry(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_delete(env, parent, (const struct dt_key *)name, th,
-                      BYPASS_CAPA);
+       rc = dt_delete(env, parent, (const struct dt_key *)name, th);
        if (rc != 0)
                GOTO(stop, rc);
 
@@ -521,7 +615,7 @@ stop:
        dt_trans_stop(env, dev, th);
 
 unlock:
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       lfsck_unlock(llh);
 
        CDEBUG(D_LFSCK, "%s: remove name entry "DFID"/%s: rc = %d\n",
               lfsck_lfsck2name(lfsck), PFID(lfsck_dto2fid(parent)), name, rc);
@@ -538,7 +632,7 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
 {
        struct dt_insert_rec    *rec    = &lfsck_env_info(env)->lti_dt_rec;
        struct dt_object        *parent = lfsck->li_lpf_root_obj;
-       struct dt_device        *dev    = lfsck->li_bottom;
+       struct dt_device        *dev    = lfsck_obj2dev(child);
        struct lfsck_bookmark   *bk     = &lfsck->li_bookmark_ram;
        struct dt_object        *bk_obj = lfsck->li_bookmark_obj;
        const struct lu_fid     *cfid   = lfsck_dto2fid(child);
@@ -570,12 +664,30 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
+       if (!dt_try_as_dir(env, child))
+               GOTO(stop, rc = -ENOTDIR);
+
        /* 2a. increase child nlink */
        rc = dt_declare_ref_add(env, child, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 3a. insert linkEA for child */
+       /* 3a. insert dot into child dir */
+       rec->rec_type = S_IFDIR;
+       rec->rec_fid = cfid;
+       rc = dt_declare_insert(env, child, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dot, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* 4a. insert dotdot into child dir */
+       rec->rec_fid = &LU_LPF_FID;
+       rc = dt_declare_insert(env, child, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dotdot, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* 5a. insert linkEA for child */
        lfsck_buf_init(&linkea_buf, ldata.ld_buf->lb_buf,
                       ldata.ld_leh->leh_len);
        rc = dt_declare_xattr_set(env, child, &linkea_buf,
@@ -583,7 +695,7 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 4a. insert name into parent dir */
+       /* 6a. insert name into parent dir */
        rec->rec_type = S_IFDIR;
        rec->rec_fid = cfid;
        rc = dt_declare_insert(env, parent, (const struct dt_rec *)rec,
@@ -591,12 +703,12 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 5a. increase parent nlink */
+       /* 7a. increase parent nlink */
        rc = dt_declare_ref_add(env, parent, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 6a. update bookmark */
+       /* 8a. update bookmark */
        rc = dt_declare_record_write(env, bk_obj,
                                     lfsck_buf_get(env, bk, len), 0, th);
        if (rc != 0)
@@ -607,49 +719,46 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
                GOTO(stop, rc);
 
        dt_write_lock(env, child, 0);
-       /* 1b.1. create child */
+       /* 1b. create child */
        rc = dt_create(env, child, la, NULL, dof, th);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       if (unlikely(!dt_try_as_dir(env, child)))
-               GOTO(unlock, rc = -ENOTDIR);
+       /* 2b. increase child nlink */
+       rc = dt_ref_add(env, child, th);
+       if (rc != 0)
+               GOTO(unlock, rc);
 
-       /* 1b.2. insert dot into child dir */
+       /* 3b. insert dot into child dir */
        rec->rec_fid = cfid;
        rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                      (const struct dt_key *)dot, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)dot, th, 1);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       /* 1b.3. insert dotdot into child dir */
+       /* 4b. insert dotdot into child dir */
        rec->rec_fid = &LU_LPF_FID;
        rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                      (const struct dt_key *)dotdot, th, BYPASS_CAPA, 1);
-       if (rc != 0)
-               GOTO(unlock, rc);
-
-       /* 2b. increase child nlink */
-       rc = dt_ref_add(env, child, th);
+                      (const struct dt_key *)dotdot, th, 1);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       /* 3b. insert linkEA for child. */
+       /* 5b. insert linkEA for child. */
        rc = dt_xattr_set(env, child, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+                         XATTR_NAME_LINK, 0, th);
        dt_write_unlock(env, child);
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 4b. insert name into parent dir */
+       /* 6b. insert name into parent dir */
        rec->rec_fid = cfid;
        rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                      (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)name, th, 1);
        if (rc != 0)
                GOTO(stop, rc);
 
        dt_write_lock(env, parent, 0);
-       /* 5b. increase parent nlink */
+       /* 7b. increase parent nlink */
        rc = dt_ref_add(env, parent, th);
        dt_write_unlock(env, parent);
        if (rc != 0)
@@ -658,7 +767,7 @@ static int lfsck_create_lpf_local(const struct lu_env *env,
        bk->lb_lpf_fid = *cfid;
        lfsck_bookmark_cpu_to_le(&lfsck->li_bookmark_disk, bk);
 
-       /* 6b. update bookmark */
+       /* 8b. update bookmark */
        rc = dt_record_write(env, bk_obj,
                             lfsck_buf_get(env, bk, len), &pos, th);
 
@@ -727,7 +836,7 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
 
        /* Transaction I: locally */
 
-       dev = lfsck->li_bottom;
+       dev = lfsck_obj2dev(child);
        th = dt_trans_create(env, dev);
        if (IS_ERR(th))
                RETURN(PTR_ERR(th));
@@ -737,12 +846,30 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
+       if (!dt_try_as_dir(env, child))
+               GOTO(stop, rc = -ENOTDIR);
+
        /* 2a. increase child nlink */
        rc = dt_declare_ref_add(env, child, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 3a. insert linkEA for child */
+       /* 3a. insert dot into child dir */
+       rec->rec_type = S_IFDIR;
+       rec->rec_fid = cfid;
+       rc = dt_declare_insert(env, child, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dot, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* 4a. insert dotdot into child dir */
+       rec->rec_fid = &LU_LPF_FID;
+       rc = dt_declare_insert(env, child, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dotdot, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* 5a. insert linkEA for child */
        lfsck_buf_init(&linkea_buf, ldata.ld_buf->lb_buf,
                       ldata.ld_leh->leh_len);
        rc = dt_declare_xattr_set(env, child, &linkea_buf,
@@ -750,7 +877,7 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       /* 4a. update bookmark */
+       /* 6a. update bookmark */
        rc = dt_declare_record_write(env, bk_obj,
                                     lfsck_buf_get(env, bk, len), 0, th);
        if (rc != 0)
@@ -761,44 +888,41 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
                GOTO(stop, rc);
 
        dt_write_lock(env, child, 0);
-       /* 1b.1. create child */
+       /* 1b. create child */
        rc = dt_create(env, child, la, NULL, dof, th);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       if (unlikely(!dt_try_as_dir(env, child)))
-               GOTO(unlock, rc = -ENOTDIR);
+       /* 2b. increase child nlink */
+       rc = dt_ref_add(env, child, th);
+       if (rc != 0)
+               GOTO(unlock, rc);
 
-       /* 1b.2. insert dot into child dir */
+       /* 3b. insert dot into child dir */
        rec->rec_type = S_IFDIR;
        rec->rec_fid = cfid;
        rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                      (const struct dt_key *)dot, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)dot, th, 1);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       /* 1b.3. insert dotdot into child dir */
+       /* 4b. insert dotdot into child dir */
        rec->rec_fid = &LU_LPF_FID;
        rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                      (const struct dt_key *)dotdot, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)dotdot, th, 1);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       /* 2b. increase child nlink */
-       rc = dt_ref_add(env, child, th);
-       if (rc != 0)
-               GOTO(unlock, rc);
-
-       /* 3b. insert linkEA for child */
+       /* 5b. insert linkEA for child */
        rc = dt_xattr_set(env, child, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+                         XATTR_NAME_LINK, 0, th);
        if (rc != 0)
                GOTO(unlock, rc);
 
        bk->lb_lpf_fid = *cfid;
        lfsck_bookmark_cpu_to_le(&lfsck->li_bookmark_disk, bk);
 
-       /* 4b. update bookmark */
+       /* 6b. update bookmark */
        rc = dt_record_write(env, bk_obj,
                             lfsck_buf_get(env, bk, len), &pos, th);
 
@@ -809,11 +933,12 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
 
        /* Transaction II: remotely */
 
-       dev = lfsck->li_next;
+       dev = lfsck_obj2dev(parent);
        th = dt_trans_create(env, dev);
        if (IS_ERR(th))
                RETURN(PTR_ERR(th));
 
+       th->th_sync = 1;
        /* 5a. insert name into parent dir */
        rec->rec_fid = cfid;
        rc = dt_declare_insert(env, parent, (const struct dt_rec *)rec,
@@ -826,13 +951,13 @@ static int lfsck_create_lpf_remote(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
        /* 5b. insert name into parent dir */
        rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                      (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)name, th, 1);
        if (rc != 0)
                GOTO(stop, rc);
 
@@ -848,7 +973,7 @@ unlock:
 stop:
        dt_trans_stop(env, dev, th);
 
-       if (rc != 0 && dev == lfsck->li_next)
+       if (rc != 0 && dev == lfsck_obj2dev(parent))
                CDEBUG(D_LFSCK, "%s: partially created the object "DFID
                       "for orphans, but failed to insert the name %s "
                       "to the .lustre/lost+found/. Such inconsistency "
@@ -882,9 +1007,9 @@ static int lfsck_create_lpf(const struct lu_env *env,
        struct dt_object_format  *dof   = &info->lti_dof;
        struct dt_object         *parent = lfsck->li_lpf_root_obj;
        struct dt_object         *child = NULL;
-       struct lustre_handle      lh    = { 0 };
+       struct lfsck_lock_handle *llh   = &info->lti_llh;
        char                      name[8];
-       int                       node  = lfsck_dev_idx(lfsck->li_bottom);
+       int                       node  = lfsck_dev_idx(lfsck);
        int                       rc    = 0;
        ENTRY;
 
@@ -892,19 +1017,19 @@ static int lfsck_create_lpf(const struct lu_env *env,
        LASSERT(parent != NULL);
        LASSERT(lfsck->li_lpf_obj == NULL);
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       snprintf(name, 8, "MDT%04x", node);
+       rc = lfsck_lock(env, lfsck, parent, name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                RETURN(rc);
 
-       snprintf(name, 8, "MDT%04x", node);
        if (fid_is_zero(&bk->lb_lpf_fid)) {
                /* There is corner case that: in former LFSCK scanning we have
                 * created the .lustre/lost+found/MDTxxxx but failed to update
                 * the lfsck_bookmark::lb_lpf_fid successfully. So need lookup
                 * it from MDT0 firstly. */
                rc = dt_lookup(env, parent, (struct dt_rec *)cfid,
-                              (const struct dt_key *)name, BYPASS_CAPA);
+                              (const struct dt_key *)name);
                if (rc != 0 && rc != -ENOENT)
                        GOTO(unlock, rc);
 
@@ -920,7 +1045,7 @@ static int lfsck_create_lpf(const struct lu_env *env,
                *cfid = bk->lb_lpf_fid;
        }
 
-       child = lfsck_object_find_by_dev(env, lfsck->li_bottom, cfid);
+       child = lfsck_object_find_bottom(env, lfsck, cfid);
        if (IS_ERR(child))
                GOTO(unlock, rc = PTR_ERR(child));
 
@@ -951,9 +1076,9 @@ static int lfsck_create_lpf(const struct lu_env *env,
        GOTO(unlock, rc);
 
 unlock:
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       lfsck_unlock(llh);
        if (rc != 0 && child != NULL && !IS_ERR(child))
-               lu_object_put(env, &child->do_lu);
+               lfsck_object_put(env, child);
 
        return rc;
 }
@@ -982,7 +1107,7 @@ static int lfsck_scan_lpf_bad_entries(const struct lu_env *env,
        int                      rc;
        ENTRY;
 
-       it = iops->init(env, parent, LUDA_64BITHASH, BYPASS_CAPA);
+       it = iops->init(env, parent, LUDA_64BITHASH);
        if (IS_ERR(it))
                RETURN(PTR_ERR(it));
 
@@ -1113,7 +1238,7 @@ static int lfsck_verify_lpf_pairs(const struct lu_env *env,
 
        fid_zero(fid);
        rc = dt_lookup(env, child, (struct dt_rec *)fid,
-                      (const struct dt_key *)dotdot, BYPASS_CAPA);
+                      (const struct dt_key *)dotdot);
        if (rc != 0)
                GOTO(linkea, rc);
 
@@ -1129,8 +1254,7 @@ static int lfsck_verify_lpf_pairs(const struct lu_env *env,
                }
 
                cname = lfsck_name_get_const(env, name, strlen(name));
-               rc = lfsck_verify_linkea(env, lfsck->li_bottom, child, cname,
-                                        &LU_LPF_FID);
+               rc = lfsck_verify_linkea(env, child, cname, &LU_LPF_FID);
                if (rc == 0)
                        rc = lfsck_update_lpf_entry(env, lfsck, parent, child,
                                                    name, type);
@@ -1138,18 +1262,18 @@ static int lfsck_verify_lpf_pairs(const struct lu_env *env,
                GOTO(out_done, rc);
        }
 
-       parent2 = lfsck_object_find_by_dev(env, lfsck->li_next, fid);
+       parent2 = lfsck_object_find_bottom(env, lfsck, fid);
        if (IS_ERR(parent2))
                GOTO(linkea, parent2);
 
        if (!dt_object_exists(parent2)) {
-               lu_object_put(env, &parent2->do_lu);
+               lfsck_object_put(env, parent2);
 
                GOTO(linkea, parent2 = ERR_PTR(-ENOENT));
        }
 
        if (!dt_try_as_dir(env, parent2)) {
-               lu_object_put(env, &parent2->do_lu);
+               lfsck_object_put(env, parent2);
 
                GOTO(linkea, parent2 = ERR_PTR(-ENOTDIR));
        }
@@ -1200,7 +1324,7 @@ linkea:
        }
 
        rc = dt_lookup(env, parent2, (struct dt_rec *)fid,
-                      (const struct dt_key *)name2, BYPASS_CAPA);
+                      (const struct dt_key *)name2);
        dt_read_unlock(env, child);
        lfsck_ibits_unlock(&lh, LCK_PR);
        if (rc != 0 && rc != -ENOENT)
@@ -1234,7 +1358,7 @@ linkea:
 
 out_put:
        if (parent2 != NULL && !IS_ERR(parent2))
-               lu_object_put(env, &parent2->do_lu);
+               lfsck_object_put(env, parent2);
 
 out_done:
        return rc;
@@ -1266,10 +1390,9 @@ int lfsck_verify_lpf(const struct lu_env *env, struct lfsck_instance *lfsck)
        struct dt_object         *child1 = NULL;
        /* child2's FID is in the name entry MDTxxxx. */
        struct dt_object         *child2 = NULL;
-       struct dt_device         *dev    = lfsck->li_bottom;
        const struct lu_name     *cname;
        char                      name[8];
-       int                       node   = lfsck_dev_idx(dev);
+       int                       node   = lfsck_dev_idx(lfsck);
        int                       rc     = 0;
        ENTRY;
 
@@ -1279,7 +1402,8 @@ int lfsck_verify_lpf(const struct lu_env *env, struct lfsck_instance *lfsck)
                RETURN(0);
 
        if (node == 0) {
-               parent = lfsck_object_find_by_dev(env, dev, &LU_LPF_FID);
+               parent = lfsck_object_find_by_dev(env, lfsck->li_bottom,
+                                                 &LU_LPF_FID);
        } else {
                struct lfsck_tgt_desc *ltd;
 
@@ -1298,7 +1422,7 @@ int lfsck_verify_lpf(const struct lu_env *env, struct lfsck_instance *lfsck)
        LASSERT(dt_object_exists(parent));
 
        if (unlikely(!dt_try_as_dir(env, parent))) {
-               lu_object_put(env, &parent->do_lu);
+               lfsck_object_put(env, parent);
 
                GOTO(put, rc = -ENOTDIR);
        }
@@ -1312,61 +1436,13 @@ int lfsck_verify_lpf(const struct lu_env *env, struct lfsck_instance *lfsck)
                               lfsck_lfsck2name(lfsck), rc);
        }
 
-       if (!fid_is_zero(&bk->lb_lpf_fid)) {
-               if (unlikely(!fid_is_norm(&bk->lb_lpf_fid))) {
-                       struct lu_fid tfid = bk->lb_lpf_fid;
-
-                       /* Invalid FID record in the bookmark file, reset it. */
-                       fid_zero(&bk->lb_lpf_fid);
-                       rc = lfsck_bookmark_store(env, lfsck);
-
-                       CDEBUG(D_LFSCK, "%s: reset invalid LPF fid "DFID
-                              " in the bookmark file: rc = %d\n",
-                              lfsck_lfsck2name(lfsck), PFID(&tfid), rc);
-
-                       if (rc != 0)
-                               GOTO(put, rc);
-               } else {
-                       child1 = lfsck_object_find_by_dev(env, dev,
-                                                         &bk->lb_lpf_fid);
-                       if (IS_ERR(child1)) {
-                               child1 = NULL;
-                               goto find_child2;
-                       }
-
-                       if (unlikely(!dt_object_exists(child1) ||
-                                    dt_object_remote(child1)) ||
-                                    !S_ISDIR(lfsck_object_type(child1))) {
-                               /* Invalid FID record in the bookmark file,
-                                * reset it. */
-                               fid_zero(&bk->lb_lpf_fid);
-                               rc = lfsck_bookmark_store(env, lfsck);
-
-                               CDEBUG(D_LFSCK, "%s: reset invalid LPF fid "DFID
-                                      " in the bookmark file: rc = %d\n",
-                                      lfsck_lfsck2name(lfsck),
-                                      PFID(lfsck_dto2fid(child1)), rc);
-
-                               if (rc != 0)
-                                       GOTO(put, rc);
-
-                               lu_object_put(env, &child1->do_lu);
-                               child1 = NULL;
-                       } else if (unlikely(!dt_try_as_dir(env, child1))) {
-                               GOTO(put, rc = -ENOTDIR);
-                       }
-               }
-       }
-
-find_child2:
+       /* child2 */
        snprintf(name, 8, "MDT%04x", node);
        rc = dt_lookup(env, parent, (struct dt_rec *)cfid,
-                      (const struct dt_key *)name, BYPASS_CAPA);
+                      (const struct dt_key *)name);
        if (rc == -ENOENT) {
-               if (!fid_is_zero(&bk->lb_lpf_fid))
-                       goto check_child1;
-
-               GOTO(put, rc = 0);
+               rc = 0;
+               goto find_child1;
        }
 
        if (rc != 0)
@@ -1378,10 +1454,10 @@ find_child2:
                if (rc != 0)
                        GOTO(put, rc);
 
-               goto check_child1;
+               goto find_child1;
        }
 
-       child2 = lfsck_object_find_by_dev(env, dev, cfid);
+       child2 = lfsck_object_find_bottom(env, lfsck, cfid);
        if (IS_ERR(child2))
                GOTO(put, rc = PTR_ERR(child2));
 
@@ -1392,45 +1468,97 @@ find_child2:
                if (rc != 0)
                        GOTO(put, rc);
 
-               goto check_child1;
+               goto find_child1;
        }
 
-       if (unlikely(!dt_try_as_dir(env, child2)))
-               GOTO(put, rc = -ENOTDIR);
+       if (unlikely(!dt_try_as_dir(env, child2))) {
+               lfsck_object_put(env, child2);
+               child2 = NULL;
+               rc = -ENOTDIR;
+       }
 
-       if (child1 == NULL) {
-               rc = lfsck_verify_lpf_pairs(env, lfsck, child2, name,
-                                           pfid, LVLT_BY_NAMEENTRY);
-       } else if (!lu_fid_eq(cfid, &bk->lb_lpf_fid)) {
-               rc = lfsck_verify_lpf_pairs(env, lfsck, child1, name,
-                                           pfid, LVLT_BY_BOOKMARK);
-               if (!lu_fid_eq(pfid, &LU_LPF_FID))
-                       rc = lfsck_verify_lpf_pairs(env, lfsck, child2,
-                                                   name, pfid,
-                                                   LVLT_BY_NAMEENTRY);
-       } else {
+find_child1:
+       if (fid_is_zero(&bk->lb_lpf_fid))
+               goto check_child2;
+
+       if (likely(lu_fid_eq(cfid, &bk->lb_lpf_fid))) {
                if (lfsck->li_lpf_obj == NULL) {
                        lu_object_get(&child2->do_lu);
                        lfsck->li_lpf_obj = child2;
                }
 
                cname = lfsck_name_get_const(env, name, strlen(name));
-               rc = lfsck_verify_linkea(env, dev, child2, cname, &LU_LPF_FID);
+               rc = lfsck_verify_linkea(env, child2, cname, &LU_LPF_FID);
+
+               GOTO(put, rc);
        }
 
-       GOTO(put, rc);
+       if (unlikely(!fid_is_norm(&bk->lb_lpf_fid))) {
+               struct lu_fid tfid = bk->lb_lpf_fid;
+
+               /* Invalid FID record in the bookmark file, reset it. */
+               fid_zero(&bk->lb_lpf_fid);
+               rc = lfsck_bookmark_store(env, lfsck);
+
+               CDEBUG(D_LFSCK, "%s: reset invalid LPF fid "DFID
+                      " in the bookmark file: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(&tfid), rc);
+
+               if (rc != 0)
+                       GOTO(put, rc);
+
+               goto check_child2;
+       }
+
+       child1 = lfsck_object_find_bottom(env, lfsck, &bk->lb_lpf_fid);
+       if (IS_ERR(child1)) {
+               child1 = NULL;
+               goto check_child2;
+       }
+
+       if (unlikely(!dt_object_exists(child1) ||
+                    dt_object_remote(child1)) ||
+                    !S_ISDIR(lfsck_object_type(child1))) {
+               /* Invalid FID record in the bookmark file, reset it. */
+               fid_zero(&bk->lb_lpf_fid);
+               rc = lfsck_bookmark_store(env, lfsck);
+
+               CDEBUG(D_LFSCK, "%s: reset invalid LPF fid "DFID
+                      " in the bookmark file: rc = %d\n",
+                      lfsck_lfsck2name(lfsck),
+                      PFID(lfsck_dto2fid(child1)), rc);
 
-check_child1:
-       if (child1 != NULL)
-               rc = lfsck_verify_lpf_pairs(env, lfsck, child1, name,
-                                           pfid, LVLT_BY_BOOKMARK);
+               if (rc != 0)
+                       GOTO(put, rc);
+
+               lfsck_object_put(env, child1);
+               child1 = NULL;
+               goto check_child2;
+       }
+
+       if (unlikely(!dt_try_as_dir(env, child1))) {
+               lfsck_object_put(env, child1);
+               child1 = NULL;
+               rc = -ENOTDIR;
+               goto check_child2;
+       }
+
+       rc = lfsck_verify_lpf_pairs(env, lfsck, child1, name, pfid,
+                                   LVLT_BY_BOOKMARK);
+       if (lu_fid_eq(pfid, &LU_LPF_FID))
+               GOTO(put, rc);
+
+check_child2:
+       if (child2 != NULL)
+               rc = lfsck_verify_lpf_pairs(env, lfsck, child2, name,
+                                           pfid, LVLT_BY_NAMEENTRY);
 
        GOTO(put, rc);
 
 put:
        if (lfsck->li_lpf_obj != NULL) {
                if (unlikely(!dt_try_as_dir(env, lfsck->li_lpf_obj))) {
-                       lu_object_put(env, &lfsck->li_lpf_obj->do_lu);
+                       lfsck_object_put(env, lfsck->li_lpf_obj);
                        lfsck->li_lpf_obj = NULL;
                        rc = -ENOTDIR;
                }
@@ -1439,9 +1567,9 @@ put:
        }
 
        if (child2 != NULL && !IS_ERR(child2))
-               lu_object_put(env, &child2->do_lu);
+               lfsck_object_put(env, child2);
        if (child1 != NULL && !IS_ERR(child1))
-               lu_object_put(env, &child1->do_lu);
+               lfsck_object_put(env, child1);
 
        return rc;
 }
@@ -1449,12 +1577,11 @@ put:
 static int lfsck_fid_init(struct lfsck_instance *lfsck)
 {
        struct lfsck_bookmark   *bk     = &lfsck->li_bookmark_ram;
-       struct seq_server_site  *ss;
+       struct seq_server_site  *ss     = lfsck_dev_site(lfsck);
        char                    *prefix;
        int                      rc     = 0;
        ENTRY;
 
-       ss = lu_site2seq(lfsck->li_bottom->dd_lu_dev.ld_site);
        if (unlikely(ss == NULL))
                RETURN(-ENXIO);
 
@@ -1509,7 +1636,7 @@ void lfsck_instance_cleanup(const struct lu_env *env,
        LASSERT(thread_is_init(thread) || thread_is_stopped(thread));
 
        if (lfsck->li_obj_oit != NULL) {
-               lu_object_put_nocache(env, &lfsck->li_obj_oit->do_lu);
+               lfsck_object_put(env, lfsck->li_obj_oit);
                lfsck->li_obj_oit = NULL;
        }
 
@@ -1545,22 +1672,22 @@ void lfsck_instance_cleanup(const struct lu_env *env,
        lfsck_tgt_descs_fini(&lfsck->li_mdt_descs);
 
        if (lfsck->li_lfsck_dir != NULL) {
-               lu_object_put_nocache(env, &lfsck->li_lfsck_dir->do_lu);
+               lfsck_object_put(env, lfsck->li_lfsck_dir);
                lfsck->li_lfsck_dir = NULL;
        }
 
        if (lfsck->li_bookmark_obj != NULL) {
-               lu_object_put_nocache(env, &lfsck->li_bookmark_obj->do_lu);
+               lfsck_object_put(env, lfsck->li_bookmark_obj);
                lfsck->li_bookmark_obj = NULL;
        }
 
        if (lfsck->li_lpf_obj != NULL) {
-               lu_object_put(env, &lfsck->li_lpf_obj->do_lu);
+               lfsck_object_put(env, lfsck->li_lpf_obj);
                lfsck->li_lpf_obj = NULL;
        }
 
        if (lfsck->li_lpf_root_obj != NULL) {
-               lu_object_put(env, &lfsck->li_lpf_root_obj->do_lu);
+               lfsck_object_put(env, lfsck->li_lpf_root_obj);
                lfsck->li_lpf_root_obj = NULL;
        }
 
@@ -1628,8 +1755,11 @@ int lfsck_bits_dump(struct seq_file *m, int bits, const char *names[],
        int flag;
        int i;
        bool newline = (bits != 0 ? false : true);
+       int rc;
 
-       seq_printf(m, "%s:%c", prefix, bits != 0 ? ' ' : '\n');
+       rc = seq_printf(m, "%s:%c", prefix, bits != 0 ? ' ' : '\n');
+       if (rc < 0)
+               return rc;
 
        for (i = 0, flag = 1; bits != 0; i++, flag = 1 << i) {
                if (flag & bits) {
@@ -1638,25 +1768,38 @@ int lfsck_bits_dump(struct seq_file *m, int bits, const char *names[],
                                if (bits == 0)
                                        newline = true;
 
-                               seq_printf(m, "%s%c", names[i],
-                                          newline ? '\n' : ',');
+                               rc = seq_printf(m, "%s%c", names[i],
+                                               newline ? '\n' : ',');
+                               if (rc < 0)
+                                       return rc;
                        }
                }
        }
 
        if (!newline)
-               seq_printf(m, "\n");
-       return 0;
+               rc = seq_printf(m, "\n");
+
+       return rc;
 }
 
-int lfsck_time_dump(struct seq_file *m, __u64 time, const char *prefix)
+int lfsck_time_dump(struct seq_file *m, __u64 time, const char *name)
 {
-       if (time != 0)
-               seq_printf(m, "%s: "LPU64" seconds\n", prefix,
-                         cfs_time_current_sec() - time);
-       else
-               seq_printf(m, "%s: N/A\n", prefix);
-       return 0;
+       int rc;
+
+       if (time == 0) {
+               rc = seq_printf(m, "%s_time: N/A\n", name);
+               if (rc == 0)
+                       rc = seq_printf(m, "time_since_%s: N/A\n", name);
+
+               return rc;
+       }
+
+       rc = seq_printf(m, "%s_time: "LPU64"\n", name, time);
+       if (rc == 0)
+               rc = seq_printf(m, "time_since_%s: "LPU64" seconds\n",
+                               name, cfs_time_current_sec() - time);
+
+       return rc;
 }
 
 int lfsck_pos_dump(struct seq_file *m, struct lfsck_position *pos,
@@ -1664,17 +1807,15 @@ int lfsck_pos_dump(struct seq_file *m, struct lfsck_position *pos,
 {
        if (fid_is_zero(&pos->lp_dir_parent)) {
                if (pos->lp_oit_cookie == 0)
-                       seq_printf(m, "%s: N/A, N/A, N/A\n",
-                                  prefix);
-               else
-                       seq_printf(m, "%s: "LPU64", N/A, N/A\n",
-                                  prefix, pos->lp_oit_cookie);
-       } else {
-               seq_printf(m, "%s: "LPU64", "DFID", "LPX64"\n",
-                          prefix, pos->lp_oit_cookie,
-                          PFID(&pos->lp_dir_parent), pos->lp_dir_cookie);
+                       return seq_printf(m, "%s: N/A, N/A, N/A\n", prefix);
+
+               return seq_printf(m, "%s: "LPU64", N/A, N/A\n",
+                                 prefix, pos->lp_oit_cookie);
        }
-       return 0;
+
+       return seq_printf(m, "%s: "LPU64", "DFID", "LPX64"\n",
+                         prefix, pos->lp_oit_cookie,
+                         PFID(&pos->lp_dir_parent), pos->lp_dir_cookie);
 }
 
 void lfsck_pos_fill(const struct lu_env *env, struct lfsck_instance *lfsck,
@@ -1839,6 +1980,56 @@ lfsck_assistant_data_init(struct lfsck_assistant_operations *lao,
        return lad;
 }
 
+struct lfsck_assistant_object *
+lfsck_assistant_object_init(const struct lu_env *env, const struct lu_fid *fid,
+                           const struct lu_attr *attr, __u64 cookie,
+                           bool is_dir)
+{
+       struct lfsck_assistant_object   *lso;
+
+       OBD_ALLOC_PTR(lso);
+       if (lso == NULL)
+               return ERR_PTR(-ENOMEM);
+
+       lso->lso_fid = *fid;
+       if (attr != NULL)
+               lso->lso_attr = *attr;
+
+       atomic_set(&lso->lso_ref, 1);
+       lso->lso_oit_cookie = cookie;
+       if (is_dir)
+               lso->lso_is_dir = 1;
+
+       return lso;
+}
+
+struct dt_object *
+lfsck_assistant_object_load(const struct lu_env *env,
+                           struct lfsck_instance *lfsck,
+                           struct lfsck_assistant_object *lso)
+{
+       struct dt_object *obj;
+
+       obj = lfsck_object_find_bottom(env, lfsck, &lso->lso_fid);
+       if (IS_ERR(obj))
+               return obj;
+
+       if (unlikely(!dt_object_exists(obj) || lfsck_is_dead_obj(obj))) {
+               lso->lso_dead = 1;
+               lfsck_object_put(env, obj);
+
+               return ERR_PTR(-ENOENT);
+       }
+
+       if (lso->lso_is_dir && unlikely(!dt_try_as_dir(env, obj))) {
+               lfsck_object_put(env, obj);
+
+               return ERR_PTR(-ENOTDIR);
+       }
+
+       return obj;
+}
+
 /**
  * Generic LFSCK asynchronous communication interpretor function.
  * The LFSCK RPC reply for both the event notification and status
@@ -2125,7 +2316,7 @@ static int lfsck_stop_notify(const struct lu_env *env,
                spin_unlock(&ltds->ltd_lock);
 
                memset(lr, 0, sizeof(*lr));
-               lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
+               lr->lr_index = lfsck_dev_idx(lfsck);
                lr->lr_event = LE_PEER_EXIT;
                lr->lr_active = type;
                lr->lr_status = LS_CO_PAUSED;
@@ -2222,6 +2413,7 @@ int lfsck_async_request(const struct lu_env *env, struct obd_export *exp,
        if (laia->laia_com != NULL)
                lfsck_component_get(laia->laia_com);
        req->rq_interpret_reply = interpreter;
+       req->rq_allow_intr = 1;
        ptlrpc_set_add_req(set, req);
 
        return 0;
@@ -2245,6 +2437,7 @@ int lfsck_start_assistant(const struct lu_env *env, struct lfsck_component *com,
        lad->lad_to_double_scan = 0;
        lad->lad_in_double_scan = 0;
        lad->lad_exit = 0;
+       lad->lad_advance_lock = false;
        thread_set_flags(athread, 0);
 
        lta = lfsck_thread_args_init(lfsck, com, lsp);
@@ -2281,9 +2474,6 @@ int lfsck_checkpoint_generic(const struct lu_env *env,
        struct ptlrpc_thread            *athread = &lad->lad_thread;
        struct l_wait_info               lwi     = { 0 };
 
-       if (com->lc_new_checked == 0)
-               return LFSCK_CHECKPOINT_SKIP;
-
        l_wait_event(mthread->t_ctl_waitq,
                     list_empty(&lad->lad_req_list) ||
                     !thread_is_running(mthread) ||
@@ -2309,6 +2499,9 @@ void lfsck_post_generic(const struct lu_env *env,
                lad->lad_exit = 1;
        lad->lad_to_post = 1;
 
+       CDEBUG(D_LFSCK, "%s: waiting for assistant to do %s post, rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), lad->lad_name, *result);
+
        wake_up_all(&athread->t_ctl_waitq);
        l_wait_event(mthread->t_ctl_waitq,
                     (*result > 0 && list_empty(&lad->lad_req_list)) ||
@@ -2317,6 +2510,9 @@ void lfsck_post_generic(const struct lu_env *env,
 
        if (lad->lad_assistant_status < 0)
                *result = lad->lad_assistant_status;
+
+       CDEBUG(D_LFSCK, "%s: the assistant has done %s post, rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), lad->lad_name, *result);
 }
 
 int lfsck_double_scan_generic(const struct lu_env *env,
@@ -2332,12 +2528,20 @@ int lfsck_double_scan_generic(const struct lu_env *env,
        else
                lad->lad_to_double_scan = 1;
 
+       CDEBUG(D_LFSCK, "%s: waiting for assistant to do %s double_scan, "
+              "status %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), lad->lad_name, status);
+
        wake_up_all(&athread->t_ctl_waitq);
        l_wait_event(mthread->t_ctl_waitq,
                     lad->lad_in_double_scan ||
                     thread_is_stopped(athread),
                     &lwi);
 
+       CDEBUG(D_LFSCK, "%s: the assistant has done %s double_scan, "
+              "status %d\n", lfsck_lfsck2name(com->lc_lfsck), lad->lad_name,
+              lad->lad_assistant_status);
+
        if (lad->lad_assistant_status < 0)
                return lad->lad_assistant_status;
 
@@ -2453,12 +2657,10 @@ int lfsck_set_windows(struct dt_device *key, int val)
 
        lfsck = lfsck_instance_find(key, true, false);
        if (likely(lfsck != NULL)) {
-               if (val > LFSCK_ASYNC_WIN_MAX) {
-                       CWARN("%s: Too large async window size, which "
-                             "may cause memory issues. The valid range "
-                             "is [0 - %u]. If you do not want to restrict "
-                             "the window size for async requests pipeline, "
-                             "just set it as 0.\n",
+               if (val < 1 || val > LFSCK_ASYNC_WIN_MAX) {
+                       CWARN("%s: invalid async windows size that may "
+                             "cause memory issues. The valid range is "
+                             "[1 - %u].\n",
                              lfsck_lfsck2name(lfsck), LFSCK_ASYNC_WIN_MAX);
                        rc = -EINVAL;
                } else if (lfsck->li_bookmark_ram.lb_async_windows != val) {
@@ -2535,7 +2737,7 @@ static int lfsck_stop_all(const struct lu_env *env,
 
        memset(lr, 0, sizeof(*lr));
        lr->lr_event = LE_STOP;
-       lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
+       lr->lr_index = lfsck_dev_idx(lfsck);
        lr->lr_status = stop->ls_status;
        lr->lr_version = bk->lb_version;
        lr->lr_active = LFSCK_TYPES_ALL;
@@ -2605,7 +2807,7 @@ static int lfsck_start_all(const struct lu_env *env,
 
        memset(lr, 0, sizeof(*lr));
        lr->lr_event = LE_START;
-       lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
+       lr->lr_index = lfsck_dev_idx(lfsck);
        lr->lr_speed = bk->lb_speed_limit;
        lr->lr_version = bk->lb_version;
        lr->lr_active = start->ls_active;
@@ -2629,6 +2831,7 @@ static int lfsck_start_all(const struct lu_env *env,
                laia->laia_ltd = ltd;
                ltd->ltd_layout_done = 0;
                ltd->ltd_namespace_done = 0;
+               ltd->ltd_synced_failures = 0;
                rc = lfsck_async_request(env, ltd->ltd_exp, lr, set,
                                         lfsck_async_interpret, laia,
                                         LFSCK_NOTIFY);
@@ -2956,6 +3159,28 @@ int lfsck_stop(const struct lu_env *env, struct dt_device *key,
        }
 
        thread_set_flags(thread, SVC_STOPPING);
+
+       if (lfsck->li_master) {
+               struct lfsck_component *com;
+               struct lfsck_assistant_data *lad;
+
+               list_for_each_entry(com, &lfsck->li_list_scan, lc_link) {
+                       lad = com->lc_data;
+                       spin_lock(&lad->lad_lock);
+                       if (lad->lad_task != NULL)
+                               force_sig(SIGINT, lad->lad_task);
+                       spin_unlock(&lad->lad_lock);
+               }
+
+               list_for_each_entry(com, &lfsck->li_list_double_scan, lc_link) {
+                       lad = com->lc_data;
+                       spin_lock(&lad->lad_lock);
+                       if (lad->lad_task != NULL)
+                               force_sig(SIGINT, lad->lad_task);
+                       spin_unlock(&lad->lad_lock);
+               }
+       }
+
        spin_unlock(&lfsck->li_lock);
 
        wake_up_all(&thread->t_ctl_waitq);
@@ -3148,13 +3373,13 @@ int lfsck_register(const struct lu_env *env, struct dt_device *key,
        lfsck->li_local_root_fid = *fid;
        if (master) {
                lfsck->li_master = 1;
-               if (lfsck_dev_idx(key) == 0) {
+               if (lfsck_dev_idx(lfsck) == 0) {
                        struct lu_fid *pfid = &lfsck_env_info(env)->lti_fid2;
                        const struct lu_name *cname;
 
                        rc = dt_lookup(env, root,
                                (struct dt_rec *)(&lfsck->li_global_root_fid),
-                               (const struct dt_key *)"ROOT", BYPASS_CAPA);
+                               (const struct dt_key *)"ROOT");
                        if (rc != 0)
                                GOTO(out, rc);
 
@@ -3166,18 +3391,18 @@ int lfsck_register(const struct lu_env *env, struct dt_device *key,
                                GOTO(out, rc = -ENOTDIR);
 
                        rc = dt_lookup(env, obj, (struct dt_rec *)fid,
-                               (const struct dt_key *)dotlustre, BYPASS_CAPA);
+                               (const struct dt_key *)dotlustre);
                        if (rc != 0)
                                GOTO(out, rc);
 
-                       lu_object_put(env, &obj->do_lu);
+                       lfsck_object_put(env, obj);
                        obj = dt_locate(env, key, fid);
                        if (IS_ERR(obj))
                                GOTO(out, rc = PTR_ERR(obj));
 
                        cname = lfsck_name_get_const(env, dotlustre,
                                                     strlen(dotlustre));
-                       rc = lfsck_verify_linkea(env, key, obj, cname,
+                       rc = lfsck_verify_linkea(env, obj, cname,
                                                 &lfsck->li_global_root_fid);
                        if (rc != 0)
                                GOTO(out, rc);
@@ -3187,23 +3412,22 @@ int lfsck_register(const struct lu_env *env, struct dt_device *key,
 
                        *pfid = *fid;
                        rc = dt_lookup(env, obj, (struct dt_rec *)fid,
-                                      (const struct dt_key *)lostfound,
-                                      BYPASS_CAPA);
+                                      (const struct dt_key *)lostfound);
                        if (rc != 0)
                                GOTO(out, rc);
 
-                       lu_object_put(env, &obj->do_lu);
+                       lfsck_object_put(env, obj);
                        obj = dt_locate(env, key, fid);
                        if (IS_ERR(obj))
                                GOTO(out, rc = PTR_ERR(obj));
 
                        cname = lfsck_name_get_const(env, lostfound,
                                                     strlen(lostfound));
-                       rc = lfsck_verify_linkea(env, key, obj, cname, pfid);
+                       rc = lfsck_verify_linkea(env, obj, cname, pfid);
                        if (rc != 0)
                                GOTO(out, rc);
 
-                       lu_object_put(env, &obj->do_lu);
+                       lfsck_object_put(env, obj);
                        obj = NULL;
                }
        }
@@ -3252,9 +3476,9 @@ int lfsck_register(const struct lu_env *env, struct dt_device *key,
                rc = lfsck_add_target_from_orphan(env, lfsck);
 out:
        if (obj != NULL && !IS_ERR(obj))
-               lu_object_put(env, &obj->do_lu);
+               lfsck_object_put(env, obj);
        if (root != NULL && !IS_ERR(root))
-               lu_object_put(env, &root->do_lu);
+               lfsck_object_put(env, root);
        if (rc != 0)
                lfsck_instance_cleanup(env, lfsck);
        return rc;
@@ -3361,7 +3585,7 @@ void lfsck_del_target(const struct lu_env *env, struct dt_device *key,
        if (unlikely(index >= ltds->ltd_tgts_bitmap->size))
                goto unlock;
 
-       ltd = LTD_TGT(ltds, index);
+       ltd = lfsck_ltd2tgt(ltds, index);
        if (unlikely(ltd == NULL))
                goto unlock;
 
@@ -3369,7 +3593,7 @@ void lfsck_del_target(const struct lu_env *env, struct dt_device *key,
 
        ltds->ltd_tgtnr--;
        cfs_bitmap_clear(ltds->ltd_tgts_bitmap, index);
-       LTD_TGT(ltds, index) = NULL;
+       lfsck_assign_tgt(ltds, NULL, index);
 
 unlock:
        if (ltd == NULL) {
@@ -3439,8 +3663,10 @@ static void __exit lfsck_exit(void)
        lu_context_key_degister(&lfsck_thread_key);
 }
 
-MODULE_AUTHOR("Intel Corporation <http://www.intel.com/>");
-MODULE_DESCRIPTION("LFSCK");
+MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
+MODULE_DESCRIPTION("Lustre File System Checker");
+MODULE_VERSION(LUSTRE_VERSION_STRING);
 MODULE_LICENSE("GPL");
 
-cfs_module(lfsck, LUSTRE_VERSION_STRING, lfsck_init, lfsck_exit);
+module_init(lfsck_init);
+module_exit(lfsck_exit);