Whamcloud - gitweb
LU-4927 scrub: rebuild stale OST OI mapping
[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_scrub.c
index 75b0b8a..d830e22 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2012, Intel Corporation.
+ * Copyright (c) 2012, 2013, Intel Corporation.
  */
 /*
  * lustre/osd-ldiskfs/osd_scrub.c
  * Author: Fan Yong <yong.fan@whamcloud.com>
  */
 
-#ifndef EXPORT_SYMTAB
-# define EXPORT_SYMTAB
-#endif
 #define DEBUG_SUBSYSTEM S_MDS
 
 #include <lustre/lustre_idl.h>
 #include <lustre_disk.h>
 #include <dt_object.h>
+#include <linux/xattr.h>
 
 #include "osd_internal.h"
 #include "osd_oi.h"
 #include "osd_scrub.h"
 
-#define HALF_SEC       (CFS_HZ >> 1)
+#define HALF_SEC       (HZ >> 1)
 
 #define OSD_OTABLE_MAX_HASH            0x00000000ffffffffULL
 
@@ -60,6 +58,9 @@
 #define SCRUB_NEXT_FATAL       6 /* simulate failure during OI scrub */
 #define SCRUB_NEXT_NOSCRUB     7 /* new created object, no scrub on it */
 #define SCRUB_NEXT_NOLMA       8 /* the inode has no FID-in-LMA */
+#define SCRUB_NEXT_OSTOBJ      9 /* for OST-object */
+#define SCRUB_NEXT_OSTOBJ_OLD  10 /* old OST-object, no LMA or no FID-on-OST
+                                   * flags in LMA */
 
 /* misc functions */
 
@@ -79,46 +80,49 @@ static inline int osd_scrub_has_window(struct osd_scrub *scrub,
        return scrub->os_pos_current < ooc->ooc_pos_preload + SCRUB_WINDOW_SIZE;
 }
 
+/**
+ * update/insert/delete the specified OI mapping (@fid @id) according to the ops
+ *
+ * \retval   1, changed nothing
+ * \retval   0, changed successfully
+ * \retval -ve, on error
+ */
 static int osd_scrub_refresh_mapping(struct osd_thread_info *info,
                                     struct osd_device *dev,
                                     const struct lu_fid *fid,
-                                    const struct osd_inode_id *id, int ops)
+                                    const struct osd_inode_id *id,
+                                    int ops, bool force,
+                                    enum oi_check_flags flags)
 {
-       struct lu_fid         *oi_fid = &info->oti_fid2;
-       struct osd_inode_id   *oi_id  = &info->oti_id2;
-       struct iam_container  *bag;
-       struct iam_path_descr *ipd;
-       handle_t              *jh;
-       int                    rc;
+       handle_t *th;
+       int       rc;
        ENTRY;
 
-       fid_cpu_to_be(oi_fid, fid);
-       osd_id_pack(oi_id, id);
-       jh = ldiskfs_journal_start_sb(osd_sb(dev),
-                                     osd_dto_credits_noquota[ops]);
-       if (IS_ERR(jh)) {
-               rc = PTR_ERR(jh);
-               CERROR("%.16s: fail to start trans for scrub store: rc = %d\n",
-                      LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name, rc);
-               RETURN(rc);
-       }
+       if (dev->od_scrub.os_file.sf_param & SP_DRYRUN && !force)
+               RETURN(0);
 
-       bag = &osd_fid2oi(dev, fid)->oi_dir.od_container;
-       ipd = osd_idx_ipd_get(info->oti_env, bag);
-       if (unlikely(ipd == NULL)) {
-               ldiskfs_journal_stop(jh);
-               CERROR("%.16s: fail to get ipd for scrub store\n",
-                      LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name);
-               RETURN(-ENOMEM);
+       /* DTO_INDEX_INSERT is enough for other two ops:
+        * delete/update, but save stack. */
+       th = ldiskfs_journal_start_sb(osd_sb(dev),
+                               osd_dto_credits_noquota[DTO_INDEX_INSERT]);
+       if (IS_ERR(th)) {
+               rc = PTR_ERR(th);
+               CERROR("%s: fail to start trans for scrub %d: rc = %d\n",
+                      osd_name(dev), ops, rc);
+               RETURN(rc);
        }
 
-       if (ops == DTO_INDEX_UPDATE) {
-               rc = iam_update(jh, bag, (const struct iam_key *)oi_fid,
-                               (struct iam_rec *)oi_id, ipd);
-       } else {
-               rc = iam_insert(jh, bag, (const struct iam_key *)oi_fid,
-                               (struct iam_rec *)oi_id, ipd);
-               if (rc == -EEXIST) {
+       switch (ops) {
+       case DTO_INDEX_UPDATE:
+               rc = osd_oi_update(info, dev, fid, id, th, flags);
+               if (unlikely(rc == -ENOENT)) {
+                       /* Some unlink thread may removed the OI mapping. */
+                       rc = 1;
+               }
+               break;
+       case DTO_INDEX_INSERT:
+               rc = osd_oi_insert(info, dev, fid, id, th, flags);
+               if (unlikely(rc == -EEXIST)) {
                        rc = 1;
                        /* XXX: There are trouble things when adding OI
                         *      mapping for IGIF object, which may cause
@@ -152,10 +156,22 @@ static int osd_scrub_refresh_mapping(struct osd_thread_info *info,
                         *
                         *      Anyway, it is rare, only exists in theory. */
                }
+               break;
+       case DTO_INDEX_DELETE:
+               rc = osd_oi_delete(info, dev, fid, th, flags);
+               if (rc == -ENOENT) {
+                       /* It is normal that the unlink thread has removed the
+                        * OI mapping already. */
+                       rc = 1;
+               }
+               break;
+       default:
+               LASSERTF(0, "Unexpected ops %d\n", ops);
+               break;
        }
-       osd_ipd_put(info->oti_env, bag, ipd);
-       ldiskfs_journal_stop(jh);
-       RETURN(rc);
+
+       ldiskfs_journal_stop(th);
+       return rc;
 }
 
 /* OI_scrub file ops */
@@ -191,6 +207,7 @@ static void osd_scrub_file_to_cpu(struct scrub_file *des,
        des->sf_run_time        = le32_to_cpu(src->sf_run_time);
        des->sf_success_count   = le32_to_cpu(src->sf_success_count);
        des->sf_oi_count        = le16_to_cpu(src->sf_oi_count);
+       des->sf_internal_flags  = le16_to_cpu(src->sf_internal_flags);
        memcpy(des->sf_oi_bitmap, src->sf_oi_bitmap, SCRUB_OI_BITMAP_SIZE);
 }
 
@@ -225,6 +242,7 @@ static void osd_scrub_file_to_le(struct scrub_file *des,
        des->sf_run_time        = cpu_to_le32(src->sf_run_time);
        des->sf_success_count   = cpu_to_le32(src->sf_success_count);
        des->sf_oi_count        = cpu_to_le16(src->sf_oi_count);
+       des->sf_internal_flags  = cpu_to_le16(src->sf_internal_flags);
        memcpy(des->sf_oi_bitmap, src->sf_oi_bitmap, SCRUB_OI_BITMAP_SIZE);
 }
 
@@ -246,7 +264,6 @@ void osd_scrub_file_reset(struct osd_scrub *scrub, __u8 *uuid, __u64 flags)
        memcpy(sf->sf_uuid, uuid, 16);
        sf->sf_status = SS_INIT;
        sf->sf_flags |= flags;
-       sf->sf_param = 0;
        sf->sf_run_time = 0;
        sf->sf_time_latest_start = 0;
        sf->sf_time_last_checkpoint = 0;
@@ -306,7 +323,7 @@ int osd_scrub_file_store(struct osd_scrub *scrub)
        dev = container_of0(scrub, struct osd_device, od_scrub);
        credits = osd_dto_credits_noquota[DTO_WRITE_BASE] +
                  osd_dto_credits_noquota[DTO_WRITE_BLOCK];
-       jh = ldiskfs_journal_start_sb(osd_sb(dev), credits);
+       jh = osd_journal_start_sb(osd_sb(dev), LDISKFS_HT_MISC, credits);
        if (IS_ERR(jh)) {
                rc = PTR_ERR(jh);
                CERROR("%.16s: fail to start trans for scrub store, rc = %d\n",
@@ -329,61 +346,81 @@ int osd_scrub_file_store(struct osd_scrub *scrub)
        return rc;
 }
 
-/* OI scrub APIs */
-
-static int osd_scrub_prep(struct osd_device *dev)
+static int
+osd_scrub_convert_ff(struct osd_thread_info *info, struct osd_device *dev,
+                    struct inode *inode, const struct lu_fid *fid)
 {
-       struct osd_scrub     *scrub  = &dev->od_scrub;
-       struct ptlrpc_thread *thread = &scrub->os_thread;
-       struct scrub_file    *sf     = &scrub->os_file;
-       __u32                 flags  = scrub->os_start_flags;
-       int                   rc;
+       struct filter_fid_old   *ff      = &info->oti_ff;
+       struct dentry           *dentry  = &info->oti_obj_dentry;
+       handle_t                *jh;
+       int                      size    = 0;
+       int                      rc;
+       bool                     removed = false;
+       bool                     reset   = true;
        ENTRY;
 
-       down_write(&scrub->os_rwsem);
-       if (flags & SS_SET_FAILOUT)
-               sf->sf_param |= SP_FAILOUT;
-
-       if (flags & SS_CLEAR_FAILOUT)
-               sf->sf_param &= ~SP_FAILOUT;
-
-       if (flags & SS_RESET)
-               osd_scrub_file_reset(scrub,
-                       LDISKFS_SB(osd_sb(dev))->s_es->s_uuid, 0);
+       if (dev->od_scrub.os_file.sf_param & SP_DRYRUN)
+               RETURN(0);
 
-       if (flags & SS_AUTO) {
-               scrub->os_full_speed = 1;
-               sf->sf_flags |= SF_AUTO;
-       } else {
-               scrub->os_full_speed = 0;
+       /* We want the LMA to fit into the 256-byte OST inode, so operate
+        * as following:
+        * 1) read old XATTR_NAME_FID and save the parent FID;
+        * 2) delete the old XATTR_NAME_FID;
+        * 3) make new LMA and add it;
+        * 4) generate new XATTR_NAME_FID with the saved parent FID and add it.
+        *
+        * Making the LMA to fit into the 256-byte OST inode can save time for
+        * normal osd_check_lma() and for other OI scrub scanning in future.
+        * So it is worth to make some slow conversion here. */
+       jh = osd_journal_start_sb(osd_sb(dev), LDISKFS_HT_MISC,
+                               osd_dto_credits_noquota[DTO_XATTR_SET] * 3);
+       if (IS_ERR(jh)) {
+               rc = PTR_ERR(jh);
+               CERROR("%s: fail to start trans for convert ff: "DFID
+                      ": rc = %d\n",
+                      osd_name(dev), PFID(fid), rc);
+               RETURN(rc);
        }
 
-       if (sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT | SF_UPGRADE))
-               scrub->os_full_speed = 1;
+       /* 1) read old XATTR_NAME_FID and save the parent FID */
+       rc = __osd_xattr_get(inode, dentry, XATTR_NAME_FID, ff, sizeof(*ff));
+       if (rc == sizeof(*ff)) {
+               /* 2) delete the old XATTR_NAME_FID */
+               ll_vfs_dq_init(inode);
+               rc = inode->i_op->removexattr(dentry, XATTR_NAME_FID);
+               if (rc != 0)
+                       GOTO(stop, rc);
 
-       scrub->os_in_prior = 0;
-       scrub->os_waiting = 0;
-       scrub->os_paused = 0;
-       scrub->os_new_checked = 0;
-       if (sf->sf_pos_last_checkpoint != 0)
-               sf->sf_pos_latest_start = sf->sf_pos_last_checkpoint + 1;
-       else
-               sf->sf_pos_latest_start = LDISKFS_FIRST_INO(osd_sb(dev)) + 1;
+               removed = true;
+       } else if (unlikely(rc == -ENODATA)) {
+               reset = false;
+       } else if (rc != sizeof(struct filter_fid)) {
+               GOTO(stop, rc = -EINVAL);
+       }
 
-       scrub->os_pos_current = sf->sf_pos_latest_start;
-       sf->sf_status = SS_SCANNING;
-       sf->sf_time_latest_start = cfs_time_current_sec();
-       sf->sf_time_last_checkpoint = sf->sf_time_latest_start;
-       rc = osd_scrub_file_store(scrub);
-       if (rc == 0) {
-               spin_lock(&scrub->os_lock);
-               thread_set_flags(thread, SVC_RUNNING);
-               spin_unlock(&scrub->os_lock);
-               cfs_waitq_broadcast(&thread->t_ctl_waitq);
+       /* 3) make new LMA and add it */
+       rc = osd_ea_fid_set(info, inode, fid, LMAC_FID_ON_OST, 0);
+       if (rc == 0 && reset)
+               size = sizeof(struct filter_fid);
+       else if (rc != 0 && removed)
+               /* If failed, we should try to add the old back. */
+               size = sizeof(struct filter_fid_old);
+
+       /* 4) generate new XATTR_NAME_FID with the saved parent FID and add it*/
+       if (size > 0) {
+               int rc1;
+
+               rc1 = __osd_xattr_set(info, inode, XATTR_NAME_FID, ff, size,
+                                     XATTR_CREATE);
+               if (rc1 != 0 && rc == 0)
+                       rc = rc1;
        }
-       up_write(&scrub->os_rwsem);
 
-       RETURN(rc);
+       GOTO(stop, rc);
+
+stop:
+       ldiskfs_journal_stop(jh);
+       return rc;
 }
 
 static int
@@ -400,6 +437,7 @@ osd_scrub_check_update(struct osd_thread_info *info, struct osd_device *dev,
        int                           ops    = DTO_INDEX_UPDATE;
        int                           idx;
        int                           rc;
+       bool                          converted = false;
        ENTRY;
 
        down_write(&scrub->os_rwsem);
@@ -417,68 +455,112 @@ osd_scrub_check_update(struct osd_thread_info *info, struct osd_device *dev,
        if (fid_is_igif(fid))
                sf->sf_items_igif++;
 
+       if (val == SCRUB_NEXT_OSTOBJ_OLD) {
+               inode = osd_iget(info, dev, lid);
+               if (IS_ERR(inode)) {
+                       rc = PTR_ERR(inode);
+                       /* Someone removed the inode. */
+                       if (rc == -ENOENT || rc == -ESTALE)
+                               rc = 0;
+                       GOTO(out, rc);
+               }
+
+               sf->sf_flags |= SF_UPGRADE;
+               sf->sf_internal_flags &= ~SIF_NO_HANDLE_OLD_FID;
+               dev->od_check_ff = 1;
+               rc = osd_scrub_convert_ff(info, dev, inode, fid);
+               if (rc != 0)
+                       GOTO(out, rc);
+
+               converted = true;
+       }
+
        if ((val == SCRUB_NEXT_NOLMA) &&
-           (!dev->od_handle_nolma || OBD_FAIL_CHECK(OBD_FAIL_FID_NOLMA)))
+           (!scrub->os_convert_igif || OBD_FAIL_CHECK(OBD_FAIL_FID_NOLMA)))
                GOTO(out, rc = 0);
 
        if ((oii != NULL && oii->oii_insert) || (val == SCRUB_NEXT_NOLMA))
                goto iget;
 
-       /* XXX: Currently, no FID-in-LMA for OST object, so osd_oi_lookup()
-        *      without checking FLD is enough.
-        *
-        *      It should be updated if FID-in-LMA for OSD object introduced
-        *      in the future. */
-       rc = osd_oi_lookup(info, dev, fid, lid2, false);
+       rc = osd_oi_lookup(info, dev, fid, lid2,
+               (val == SCRUB_NEXT_OSTOBJ ||
+                val == SCRUB_NEXT_OSTOBJ_OLD) ? OI_KNOWN_ON_OST : 0);
        if (rc != 0) {
-               if (rc != -ENOENT)
+               if (rc != -ENOENT && rc != -ESTALE)
                        GOTO(out, rc);
 
 iget:
-               inode = osd_iget(info, dev, lid);
-               if (IS_ERR(inode)) {
-                       rc = PTR_ERR(inode);
-                       /* Someone removed the inode. */
-                       if (rc == -ENOENT || rc == -ESTALE)
-                               rc = 0;
-                       GOTO(out, rc);
-               }
-
-               /* Prevent the inode to be unlinked during OI scrub. */
-               mutex_lock(&inode->i_mutex);
-               if (unlikely(inode->i_nlink == 0)) {
-                       mutex_unlock(&inode->i_mutex);
-                       iput(inode);
-                       GOTO(out, rc = 0);
+               if (inode == NULL) {
+                       inode = osd_iget(info, dev, lid);
+                       if (IS_ERR(inode)) {
+                               rc = PTR_ERR(inode);
+                               /* Someone removed the inode. */
+                               if (rc == -ENOENT || rc == -ESTALE)
+                                       rc = 0;
+                               GOTO(out, rc);
+                       }
                }
 
+               scrub->os_full_speed = 1;
                ops = DTO_INDEX_INSERT;
                idx = osd_oi_fid2idx(dev, fid);
-               if (val == SCRUB_NEXT_NOLMA) {
+               switch (val) {
+               case SCRUB_NEXT_NOLMA:
                        sf->sf_flags |= SF_UPGRADE;
-                       scrub->os_full_speed = 1;
-                       rc = osd_ea_fid_set(info, inode, fid, 0);
-                       if (rc != 0)
-                               GOTO(out, rc);
-               } else {
-                       sf->sf_flags |= SF_RECREATED | SF_INCONSISTENT;
-                       scrub->os_full_speed = 1;
+                       if (!(sf->sf_param & SP_DRYRUN)) {
+                               rc = osd_ea_fid_set(info, inode, fid, 0, 0);
+                               if (rc != 0)
+                                       GOTO(out, rc);
+                       }
+
+                       if (!(sf->sf_flags & SF_INCONSISTENT))
+                               dev->od_igif_inoi = 0;
+                       break;
+               case SCRUB_NEXT_OSTOBJ:
+                       sf->sf_flags |= SF_INCONSISTENT;
+               case SCRUB_NEXT_OSTOBJ_OLD:
+                       break;
+               default:
+                       sf->sf_flags |= SF_RECREATED;
                        if (unlikely(!ldiskfs_test_bit(idx, sf->sf_oi_bitmap)))
                                ldiskfs_set_bit(idx, sf->sf_oi_bitmap);
+                       break;
                }
        } else if (osd_id_eq(lid, lid2)) {
+               if (converted)
+                       sf->sf_items_updated++;
+
                GOTO(out, rc = 0);
        } else {
-               sf->sf_flags |= SF_INCONSISTENT;
                scrub->os_full_speed = 1;
+               sf->sf_flags |= SF_INCONSISTENT;
+
+               /* XXX: If the device is restored from file-level backup, then
+                *      some IGIFs may have been already in OI files, and some
+                *      may be not yet. Means upgrading from 1.8 may be partly
+                *      processed, but some clients may hold some immobilized
+                *      IGIFs, and use them to access related objects. Under
+                *      such case, OSD does not know whether an given IGIF has
+                *      been processed or to be processed, and it also cannot
+                *      generate local ino#/gen# directly from the immobilized
+                *      IGIF because of the backup/restore. Then force OSD to
+                *      lookup the given IGIF in OI files, and if no entry,
+                *      then ask the client to retry after upgrading completed.
+                *      No better choice. */
+               dev->od_igif_inoi = 1;
        }
 
-       rc = osd_scrub_refresh_mapping(info, dev, fid, lid, ops);
+       rc = osd_scrub_refresh_mapping(info, dev, fid, lid, ops, false,
+                       (val == SCRUB_NEXT_OSTOBJ ||
+                        val == SCRUB_NEXT_OSTOBJ_OLD) ? OI_KNOWN_ON_OST : 0);
        if (rc == 0) {
                if (scrub->os_in_prior)
                        sf->sf_items_updated_prior++;
                else
                        sf->sf_items_updated++;
+
+               /* The target has been changed, need to be re-loaded. */
+               lu_object_purge(info->oti_env, osd2lu_dev(dev), fid);
        }
 
        GOTO(out, rc);
@@ -493,12 +575,20 @@ out:
                rc = 0;
        }
 
-       if (ops == DTO_INDEX_INSERT) {
-               mutex_unlock(&inode->i_mutex);
-               iput(inode);
-       }
+       /* There may be conflict unlink during the OI scrub,
+        * if happend, then remove the new added OI mapping. */
+       if (ops == DTO_INDEX_INSERT && inode != NULL && !IS_ERR(inode) &&
+           unlikely(inode->i_nlink == 0))
+               osd_scrub_refresh_mapping(info, dev, fid, lid,
+                               DTO_INDEX_DELETE, false,
+                               (val == SCRUB_NEXT_OSTOBJ ||
+                                val == SCRUB_NEXT_OSTOBJ_OLD) ?
+                               OI_KNOWN_ON_OST : 0);
        up_write(&scrub->os_rwsem);
 
+       if (inode != NULL && !IS_ERR(inode))
+               iput(inode);
+
        if (oii != NULL) {
                LASSERT(!cfs_list_empty(&oii->oii_list));
 
@@ -510,6 +600,78 @@ out:
        RETURN(sf->sf_param & SP_FAILOUT ? rc : 0);
 }
 
+/* OI scrub APIs */
+
+static int osd_scrub_prep(struct osd_device *dev)
+{
+       struct osd_scrub     *scrub  = &dev->od_scrub;
+       struct ptlrpc_thread *thread = &scrub->os_thread;
+       struct scrub_file    *sf     = &scrub->os_file;
+       __u32                 flags  = scrub->os_start_flags;
+       int                   rc;
+       bool                  drop_dryrun = false;
+       ENTRY;
+
+       down_write(&scrub->os_rwsem);
+       if (flags & SS_SET_FAILOUT)
+               sf->sf_param |= SP_FAILOUT;
+
+       if (flags & SS_CLEAR_FAILOUT)
+               sf->sf_param &= ~SP_FAILOUT;
+
+       if (flags & SS_SET_DRYRUN)
+               sf->sf_param |= SP_DRYRUN;
+
+       if (flags & SS_CLEAR_DRYRUN && sf->sf_param & SP_DRYRUN) {
+               sf->sf_param &= ~SP_DRYRUN;
+               drop_dryrun = true;
+       }
+
+       if (flags & SS_RESET)
+               osd_scrub_file_reset(scrub,
+                       LDISKFS_SB(osd_sb(dev))->s_es->s_uuid, 0);
+
+       if (flags & SS_AUTO) {
+               scrub->os_full_speed = 1;
+               sf->sf_flags |= SF_AUTO;
+               /* For the case of OI scrub auto triggered, NOT dryrun. */
+               sf->sf_param &= ~SP_FAILOUT;
+       } else {
+               scrub->os_full_speed = 0;
+       }
+
+       if (sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT | SF_UPGRADE))
+               scrub->os_full_speed = 1;
+
+       scrub->os_in_prior = 0;
+       spin_lock(&scrub->os_lock);
+       scrub->os_waiting = 0;
+       scrub->os_paused = 0;
+       spin_unlock(&scrub->os_lock);
+       scrub->os_new_checked = 0;
+       if (drop_dryrun && sf->sf_pos_first_inconsistent != 0)
+               sf->sf_pos_latest_start = sf->sf_pos_first_inconsistent;
+       else if (sf->sf_pos_last_checkpoint != 0)
+               sf->sf_pos_latest_start = sf->sf_pos_last_checkpoint + 1;
+       else
+               sf->sf_pos_latest_start = LDISKFS_FIRST_INO(osd_sb(dev)) + 1;
+
+       scrub->os_pos_current = sf->sf_pos_latest_start;
+       sf->sf_status = SS_SCANNING;
+       sf->sf_time_latest_start = cfs_time_current_sec();
+       sf->sf_time_last_checkpoint = sf->sf_time_latest_start;
+       rc = osd_scrub_file_store(scrub);
+       if (rc == 0) {
+               spin_lock(&scrub->os_lock);
+               thread_set_flags(thread, SVC_RUNNING);
+               spin_unlock(&scrub->os_lock);
+               wake_up_all(&thread->t_ctl_waitq);
+       }
+       up_write(&scrub->os_rwsem);
+
+       RETURN(rc);
+}
+
 static int osd_scrub_checkpoint(struct osd_scrub *scrub)
 {
        struct scrub_file *sf = &scrub->os_file;
@@ -549,10 +711,17 @@ static void osd_scrub_post(struct osd_scrub *scrub, int result)
        }
        sf->sf_time_last_checkpoint = cfs_time_current_sec();
        if (result > 0) {
+               struct osd_device *dev =
+                       container_of0(scrub, struct osd_device, od_scrub);
+
+               dev->od_igif_inoi = 1;
+               dev->od_check_ff = 0;
                sf->sf_status = SS_COMPLETED;
-               memset(sf->sf_oi_bitmap, 0, SCRUB_OI_BITMAP_SIZE);
-               sf->sf_flags &= ~(SF_RECREATED | SF_INCONSISTENT |
-                                 SF_UPGRADE | SF_AUTO);
+               if (!(sf->sf_param & SP_DRYRUN)) {
+                       memset(sf->sf_oi_bitmap, 0, SCRUB_OI_BITMAP_SIZE);
+                       sf->sf_flags &= ~(SF_RECREATED | SF_INCONSISTENT |
+                                         SF_UPGRADE | SF_AUTO);
+               }
                sf->sf_time_last_complete = sf->sf_time_last_checkpoint;
                sf->sf_success_count++;
        } else if (result == 0) {
@@ -610,13 +779,118 @@ static int osd_iit_next(struct osd_iit_param *param, __u32 *pos)
        }
 }
 
+/**
+ * \retval SCRUB_NEXT_OSTOBJ_OLD: FID-on-OST
+ * \retval 0: FID-on-MDT
+ */
+static int osd_scrub_check_local_fldb(struct osd_thread_info *info,
+                                     struct osd_device *dev,
+                                     struct lu_fid *fid)
+{
+       /* XXX: The initial OI scrub will scan the top level /O to generate
+        *      a small local FLDB according to the <seq>. If the given FID
+        *      is in the local FLDB, then it is FID-on-OST; otherwise it's
+        *      quite possible for FID-on-MDT. */
+       if (dev->od_is_ost)
+               return SCRUB_NEXT_OSTOBJ_OLD;
+       else
+               return 0;
+}
+
+static int osd_scrub_get_fid(struct osd_thread_info *info,
+                            struct osd_device *dev, struct inode *inode,
+                            struct lu_fid *fid, bool scrub)
+{
+       struct lustre_mdt_attrs *lma     = &info->oti_mdt_attrs;
+       int                      rc;
+       bool                     has_lma = false;
+
+       rc = osd_get_lma(info, inode, &info->oti_obj_dentry, lma);
+       if (rc == 0) {
+               has_lma = true;
+               if (lma->lma_compat & LMAC_NOT_IN_OI ||
+                   lma->lma_incompat & LMAI_AGENT)
+                       return SCRUB_NEXT_CONTINUE;
+
+               *fid = lma->lma_self_fid;
+               if (!scrub)
+                       return 0;
+
+               if (lma->lma_compat & LMAC_FID_ON_OST)
+                       return SCRUB_NEXT_OSTOBJ;
+
+               if (fid_is_idif(fid))
+                       return SCRUB_NEXT_OSTOBJ_OLD;
+
+               /* For local object. */
+               if (fid_is_internal(fid))
+                       return 0;
+
+               /* For external visible MDT-object with non-normal FID. */
+               if (fid_is_namespace_visible(fid) && !fid_is_norm(fid))
+                       return 0;
+
+               /* For the object with normal FID, it may be MDT-object,
+                * or may be 2.4 OST-object, need further distinguish.
+                * Fall through to next section. */
+       }
+
+       if (rc == -ENODATA || rc == 0) {
+               rc = osd_get_idif(info, inode, &info->oti_obj_dentry, fid);
+               if (rc == 0) {
+                       if (scrub)
+                               /* It is old 2.x (x <= 3) or 1.8 OST-object. */
+                               rc = SCRUB_NEXT_OSTOBJ_OLD;
+                       return rc;
+               }
+
+               if (rc > 0) {
+                       if (!has_lma)
+                               /* It is FID-on-OST, but we do not know how
+                                * to generate its FID, ignore it directly. */
+                               rc = SCRUB_NEXT_CONTINUE;
+                       else
+                               /* It is 2.4 OST-object. */
+                               rc = SCRUB_NEXT_OSTOBJ_OLD;
+                       return rc;
+               }
+
+               if (rc != -ENODATA)
+                       return rc;
+
+               if (!has_lma) {
+                       if (dev->od_scrub.os_convert_igif) {
+                               lu_igif_build(fid, inode->i_ino,
+                                             inode->i_generation);
+                               if (scrub)
+                                       rc = SCRUB_NEXT_NOLMA;
+                               else
+                                       rc = 0;
+                       } else {
+                               /* It may be FID-on-OST, or may be FID for
+                                * non-MDT0, anyway, we do not know how to
+                                * generate its FID, ignore it directly. */
+                               rc = SCRUB_NEXT_CONTINUE;
+                       }
+                       return rc;
+               }
+
+               /* For OI scrub case only: the object has LMA but has no ff
+                * (or ff crashed). It may be MDT-object, may be OST-object
+                * with crashed ff. The last check is local FLDB. */
+               rc = osd_scrub_check_local_fldb(info, dev, fid);
+       }
+
+       return rc;
+}
+
 static int osd_iit_iget(struct osd_thread_info *info, struct osd_device *dev,
                        struct lu_fid *fid, struct osd_inode_id *lid, __u32 pos,
                        struct super_block *sb, bool scrub)
 {
-       struct lustre_mdt_attrs *lma   = &info->oti_mdt_attrs;
-       struct inode            *inode;
-       int                      rc;
+       struct inode *inode;
+       int           rc;
+       ENTRY;
 
        osd_id_gen(lid, pos, OSD_OII_NOGEN);
        inode = osd_iget(info, dev, lid);
@@ -625,42 +899,25 @@ static int osd_iit_iget(struct osd_thread_info *info, struct osd_device *dev,
                /* The inode may be removed after bitmap searching, or the
                 * file is new created without inode initialized yet. */
                if (rc == -ENOENT || rc == -ESTALE)
-                       return SCRUB_NEXT_CONTINUE;
+                       RETURN(SCRUB_NEXT_CONTINUE);
 
                CERROR("%.16s: fail to read inode, ino# = %u, rc = %d\n",
                       LDISKFS_SB(sb)->s_es->s_volume_name, pos, rc);
-               return rc;
-       }
-
-       /* If the inode has no OI mapping, then it is special locally used,
-        * should be invisible to OI scrub or up layer LFSCK. */
-       if (ldiskfs_test_inode_state(inode, LDISKFS_STATE_LUSTRE_NO_OI)) {
-               iput(inode);
-               return SCRUB_NEXT_CONTINUE;
+               RETURN(rc);
        }
 
        if (scrub &&
            ldiskfs_test_inode_state(inode, LDISKFS_STATE_LUSTRE_NOSCRUB)) {
                /* Only skip it for the first OI scrub accessing. */
                ldiskfs_clear_inode_state(inode, LDISKFS_STATE_LUSTRE_NOSCRUB);
-               iput(inode);
-               return SCRUB_NEXT_NOSCRUB;
+               GOTO(put, rc = SCRUB_NEXT_NOSCRUB);
        }
 
-       rc = osd_get_lma(info, inode, &info->oti_obj_dentry, lma);
-       if (rc == 0) {
-               if (fid_is_llog(&lma->lma_self_fid) ||
-                   (!scrub && fid_is_internal(&lma->lma_self_fid)))
-                       rc = SCRUB_NEXT_CONTINUE;
-               else
-                       *fid = lma->lma_self_fid;
-       } else if (rc == -ENODATA) {
-               lu_igif_build(fid, inode->i_ino, inode->i_generation);
-               if (scrub)
-                       rc = SCRUB_NEXT_NOLMA;
-               else
-                       rc = 0;
-       }
+       rc = osd_scrub_get_fid(info, dev, inode, fid, scrub);
+
+       GOTO(put, rc);
+
+put:
        iput(inode);
        return rc;
 }
@@ -812,11 +1069,11 @@ next:
        scrub->os_pos_current = param->gbase + ++(param->offset);
 
 wait:
-       if (it != NULL && it->ooi_waiting &&
+       if (it != NULL && it->ooi_waiting && ooc != NULL &&
            ooc->ooc_pos_preload < scrub->os_pos_current) {
                spin_lock(&scrub->os_lock);
                it->ooi_waiting = 0;
-               cfs_waitq_broadcast(&thread->t_ctl_waitq);
+               wake_up_all(&thread->t_ctl_waitq);
                spin_unlock(&scrub->os_lock);
        }
 
@@ -924,18 +1181,10 @@ static int osd_inode_iteration(struct osd_thread_info *info,
                                brelse(param.bitmap);
                                RETURN(rc);
                        }
-
-                       if (preload && dev->od_otable_it->ooi_stopping) {
-                               brelse(param.bitmap);
-                               RETURN(0);
-                       }
                }
 
 next_group:
                brelse(param.bitmap);
-
-               if (preload && dev->od_otable_it->ooi_stopping)
-                       RETURN(0);
        }
 
        if (*pos > limit)
@@ -962,8 +1211,10 @@ static int osd_otable_it_preload(const struct lu_env *env,
               ooc->ooc_pos_preload, rc);
 
        if (scrub->os_waiting && osd_scrub_has_window(scrub, ooc)) {
+               spin_lock(&scrub->os_lock);
                scrub->os_waiting = 0;
-               cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
+               wake_up_all(&scrub->os_thread.t_ctl_waitq);
+               spin_unlock(&scrub->os_lock);
        }
 
        RETURN(rc < 0 ? rc : ooc->ooc_cached_items);
@@ -979,8 +1230,7 @@ static int osd_scrub_main(void *args)
        int                   rc;
        ENTRY;
 
-       cfs_daemonize("OI_scrub");
-       rc = lu_env_init(&env, LCT_DT_THREAD);
+       rc = lu_env_init(&env, LCT_LOCAL);
        if (rc != 0) {
                CERROR("%.16s: OI scrub, fail to init env, rc = %d\n",
                       LDISKFS_SB(sb)->s_es->s_volume_name, rc);
@@ -1005,7 +1255,6 @@ static int osd_scrub_main(void *args)
                if (unlikely(!thread_is_running(thread)))
                        GOTO(post, rc = 0);
 
-               LASSERT(scrub->os_pos_current >= ooc->ooc_pos_preload);
                scrub->os_pos_current = ooc->ooc_pos_preload;
        }
 
@@ -1036,7 +1285,7 @@ out:
 noenv:
        spin_lock(&scrub->os_lock);
        thread_set_flags(thread, SVC_STOPPED);
-       cfs_waitq_broadcast(&thread->t_ctl_waitq);
+       wake_up_all(&thread->t_ctl_waitq);
        spin_unlock(&scrub->os_lock);
        return rc;
 }
@@ -1048,6 +1297,10 @@ typedef int (*scandir_t)(struct osd_thread_info *, struct osd_device *,
 
 static int osd_ios_varfid_fill(void *buf, const char *name, int namelen,
                               loff_t offset, __u64 ino, unsigned d_type);
+static int osd_ios_lf_fill(void *buf, const char *name, int namelen,
+                          loff_t offset, __u64 ino, unsigned d_type);
+static int osd_ios_dl_fill(void *buf, const char *name, int namelen,
+                          loff_t offset, __u64 ino, unsigned d_type);
 
 static int
 osd_ios_general_scan(struct osd_thread_info *info, struct osd_device *dev,
@@ -1064,6 +1317,7 @@ enum osd_lf_flags {
        OLF_SCAN_SUBITEMS       = 0x0001,
        OLF_HIDE_FID            = 0x0002,
        OLF_SHOW_NAME           = 0x0004,
+       OLF_NO_OI               = 0x0008,
 };
 
 struct osd_lf_map {
@@ -1090,16 +1344,12 @@ static const struct osd_lf_map osd_lf_maps[] = {
                osd_ios_general_scan, osd_ios_varfid_fill },
 
        /* PENDING */
-       { "PENDING", { FID_SEQ_LOCAL_FILE, MDD_ORPHAN_OID, 0 }, 0, NULL, NULL },
+       { "PENDING", { 0, 0, 0 }, 0, NULL, NULL },
 
        /* ROOT */
-       { "ROOT", { FID_SEQ_LOCAL_FILE, MDD_ROOT_INDEX_OID, 0 },
+       { "ROOT", { FID_SEQ_ROOT, 1, 0 },
                OLF_SCAN_SUBITEMS | OLF_HIDE_FID, osd_ios_ROOT_scan, NULL },
 
-       /* capa_keys */
-       { CAPA_KEYS, { FID_SEQ_LOCAL_FILE, MDD_CAPA_KEYS_OID, 0 }, 0,
-               NULL, NULL },
-
        /* changelog_catalog */
        { CHANGELOG_CATALOG, { 0, 0, 0 }, 0, NULL, NULL },
 
@@ -1115,8 +1365,7 @@ static const struct osd_lf_map osd_lf_maps[] = {
                NULL, NULL },
 
        /* lfsck_bookmark */
-       { "lfsck_bookmark", { FID_SEQ_LOCAL_FILE, LFSCK_BOOKMARK_OID, 0 }, 0,
-               NULL, NULL },
+       { "lfsck_bookmark", { 0, 0, 0 }, 0, NULL, NULL },
 
        /* lov_objid */
        { LOV_OBJID, { FID_SEQ_LOCAL_FILE, MDD_LOV_OBJ_OID, 0 }, OLF_SHOW_NAME,
@@ -1134,10 +1383,6 @@ static const struct osd_lf_map osd_lf_maps[] = {
        { QSD_DIR, { 0, 0, 0 }, OLF_SCAN_SUBITEMS,
                osd_ios_general_scan, osd_ios_varfid_fill },
 
-       /* seq-200000003-lastid */
-       { "seq-200000003-lastid", { FID_SEQ_LOCAL_NAME, 1, 0 }, 0,
-               NULL, NULL },
-
        /* seq_ctl */
        { "seq_ctl", { FID_SEQ_LOCAL_FILE, FID_SEQ_CTL_OID, 0 },
                OLF_SHOW_NAME, NULL, NULL },
@@ -1146,17 +1391,12 @@ static const struct osd_lf_map osd_lf_maps[] = {
        { "seq_srv", { FID_SEQ_LOCAL_FILE, FID_SEQ_SRV_OID, 0 },
                OLF_SHOW_NAME, NULL, NULL },
 
-       /* LAST_GROUP */
-       { "LAST_GROUP", { FID_SEQ_LOCAL_FILE, OFD_LAST_GROUP_OID, 0 },
-               OLF_SHOW_NAME, NULL, NULL },
-
        /* health_check */
        { HEALTH_CHECK, { FID_SEQ_LOCAL_FILE, OFD_HEALTH_CHECK_OID, 0 },
                OLF_SHOW_NAME, NULL, NULL },
 
        /* lfsck_namespace */
-       { "lfsck_namespace", { FID_SEQ_LOCAL_FILE, LFSCK_NAMESPACE_OID, 0 }, 0,
-               NULL, NULL },
+       { "lfsck_namespace", { 0, 0, 0 }, 0, NULL, NULL },
 
        /* OBJECTS, upgrade from old device */
        { OBJECTS, { 0, 0, 0 }, OLF_SCAN_SUBITEMS, osd_ios_OBJECTS_scan, NULL },
@@ -1167,6 +1407,31 @@ static const struct osd_lf_map osd_lf_maps[] = {
        /* lquota_v2.group, upgrade from old device */
        { "lquota_v2.group", { 0, 0, 0 }, 0, NULL, NULL },
 
+       /* LAST_GROUP, upgrade from old device */
+       { "LAST_GROUP", { FID_SEQ_LOCAL_FILE, OFD_LAST_GROUP_OID, 0 },
+               OLF_SHOW_NAME, NULL, NULL },
+
+       /* SLAVE_LOG, llog for destroy slave stripes of striped dir */
+       { "SLAVE_LOG", { FID_SEQ_LOCAL_FILE, SLAVE_LLOG_CATALOGS_OID, 0 },
+              OLF_SHOW_NAME, NULL, NULL },
+
+       /* lost+found */
+       { "lost+found", { 0, 0, 0 }, OLF_SCAN_SUBITEMS | OLF_NO_OI,
+               osd_ios_general_scan, osd_ios_lf_fill },
+
+       { NULL, { 0, 0, 0 }, 0, NULL, NULL }
+};
+
+/* Add the new introduced files under .lustre/ in the list in the future. */
+static const struct osd_lf_map osd_dl_maps[] = {
+       /* .lustre/fid */
+       { "fid", { FID_SEQ_DOT_LUSTRE, FID_OID_DOT_LUSTRE_OBF, 0 }, 0,
+               NULL, NULL },
+
+       /* .lustre/lost+found */
+       { "lost+found", { FID_SEQ_DOT_LUSTRE, FID_OID_DOT_LUSTRE_LPF, 0 }, 0,
+               NULL, NULL },
+
        { NULL, { 0, 0, 0 }, 0, NULL, NULL }
 };
 
@@ -1178,6 +1443,10 @@ struct osd_ios_item {
 };
 
 struct osd_ios_filldir_buf {
+#ifdef HAVE_DIR_CONTEXT
+       /* please keep it as first member */
+       struct dir_context       ctx;
+#endif
        struct osd_thread_info  *oifb_info;
        struct osd_device       *oifb_dev;
        struct dentry           *oifb_dentry;
@@ -1188,6 +1457,9 @@ osd_ios_lookup_one_len(const char *name, struct dentry *parent, int namelen)
 {
        struct dentry *dentry;
 
+       CDEBUG(D_LFSCK, "init lookup one: parent = %.*s, name = %.*s\n",
+              parent->d_name.len, parent->d_name.name, namelen, name);
+
        dentry = ll_lookup_one_len(name, parent, namelen);
        if (!IS_ERR(dentry) && dentry->d_inode == NULL) {
                dput(dentry);
@@ -1197,48 +1469,24 @@ osd_ios_lookup_one_len(const char *name, struct dentry *parent, int namelen)
        return dentry;
 }
 
-static inline void
-osd_ios_llogname2fid(struct lu_fid *fid, const char *name, int namelen)
-{
-       obd_id id = 0;
-       int    i  = 0;
-
-       fid->f_seq = FID_SEQ_LLOG;
-       while (i < namelen)
-               id = id * 10 + name[i++] - '0';
-
-       fid->f_oid = id & 0x00000000ffffffffULL;
-       fid->f_ver = id >> 32;
-}
-
-static inline void
-osd_ios_Oname2fid(struct lu_fid *fid, const char *name, int namelen)
-{
-       __u64 seq = 0;
-       int   i   = 0;
-
-       while (i < namelen)
-               seq = seq * 10 + name[i++] - '0';
-
-       lu_last_id_fid(fid, seq);
-}
-
 static int
 osd_ios_new_item(struct osd_device *dev, struct dentry *dentry,
                 scandir_t scandir, filldir_t filldir)
 {
        struct osd_ios_item *item;
+       ENTRY;
 
        OBD_ALLOC_PTR(item);
        if (item == NULL)
-               return -ENOMEM;
+               RETURN(-ENOMEM);
 
        CFS_INIT_LIST_HEAD(&item->oii_list);
        item->oii_dentry = dget(dentry);
        item->oii_scandir = scandir;
        item->oii_filldir = filldir;
        cfs_list_add_tail(&item->oii_list, &dev->od_ios_list);
-       return 0;
+
+       RETURN(0);
 }
 
 /**
@@ -1261,6 +1509,8 @@ osd_ios_scan_one(struct osd_thread_info *info, struct osd_device *dev,
        int                      rc;
        ENTRY;
 
+       CDEBUG(D_LFSCK, "init scan one: ino = %ld\n", inode->i_ino);
+
        rc = osd_get_lma(info, inode, &info->oti_obj_dentry, lma);
        if (rc != 0 && rc != -ENODATA)
                RETURN(rc);
@@ -1271,20 +1521,26 @@ osd_ios_scan_one(struct osd_thread_info *info, struct osd_device *dev,
                        lu_igif_build(&tfid, inode->i_ino, inode->i_generation);
                else
                        tfid = *fid;
-               rc = osd_ea_fid_set(info, inode, &tfid, 0);
+               rc = osd_ea_fid_set(info, inode, &tfid, 0, 0);
                if (rc != 0)
                        RETURN(rc);
        } else {
+               if (lma->lma_compat & LMAC_NOT_IN_OI)
+                       RETURN(0);
+
                tfid = lma->lma_self_fid;
        }
 
-       rc = __osd_oi_lookup(info, dev, &tfid, id2);
+       rc = osd_oi_lookup(info, dev, &tfid, id2, 0);
        if (rc != 0) {
                if (rc != -ENOENT)
                        RETURN(rc);
 
                rc = osd_scrub_refresh_mapping(info, dev, &tfid, id,
-                                              DTO_INDEX_INSERT);
+                                              DTO_INDEX_INSERT, true, 0);
+               if (rc > 0)
+                       rc = 0;
+
                RETURN(rc);
        }
 
@@ -1300,11 +1556,85 @@ osd_ios_scan_one(struct osd_thread_info *info, struct osd_device *dev,
                        RETURN(rc);
        }
 
-       rc = osd_scrub_refresh_mapping(info, dev, &tfid, id, DTO_INDEX_UPDATE);
+       rc = osd_scrub_refresh_mapping(info, dev, &tfid, id,
+                                      DTO_INDEX_UPDATE, true, 0);
+       if (rc > 0)
+               rc = 0;
 
        RETURN(rc);
 }
 
+/**
+ * It scans the /lost+found, and for the OST-object (with filter_fid
+ * or filter_fid_old), move them back to its proper /O/<seq>/d<x>.
+ */
+static int osd_ios_lf_fill(void *buf, const char *name, int namelen,
+                          loff_t offset, __u64 ino, unsigned d_type)
+{
+       struct osd_ios_filldir_buf *fill_buf = buf;
+       struct osd_thread_info     *info     = fill_buf->oifb_info;
+       struct osd_device          *dev      = fill_buf->oifb_dev;
+       struct lu_fid              *fid      = &info->oti_fid;
+       struct osd_scrub           *scrub    = &dev->od_scrub;
+       struct dentry              *parent   = fill_buf->oifb_dentry;
+       struct dentry              *child;
+       struct inode               *dir      = parent->d_inode;
+       struct inode               *inode;
+       int                         rc;
+       ENTRY;
+
+       /* skip any '.' started names */
+       if (name[0] == '.')
+               RETURN(0);
+
+       scrub->os_lf_scanned++;
+       child = osd_ios_lookup_one_len(name, parent, namelen);
+       if (IS_ERR(child)) {
+               CWARN("%s: cannot lookup child '%.*s': rc = %d\n",
+                     osd_name(dev), namelen, name, (int)PTR_ERR(child));
+               RETURN(0);
+       }
+
+       inode = child->d_inode;
+       if (S_ISDIR(inode->i_mode)) {
+               rc = osd_ios_new_item(dev, child, osd_ios_general_scan,
+                                     osd_ios_lf_fill);
+               if (rc != 0)
+                       CWARN("%s: cannot add child '%.*s': rc = %d\n",
+                             osd_name(dev), namelen, name, rc);
+               GOTO(put, rc);
+       }
+
+       if (!S_ISREG(inode->i_mode))
+               GOTO(put, rc = 0);
+
+       rc = osd_scrub_get_fid(info, dev, inode, fid, true);
+       if (rc == SCRUB_NEXT_OSTOBJ || rc == SCRUB_NEXT_OSTOBJ_OLD) {
+               rc = osd_obj_map_recover(info, dev, dir, child, fid);
+               if (rc == 0) {
+                       CDEBUG(D_LFSCK, "recovered '%.*s' ["DFID"] from "
+                              "/lost+found.\n", namelen, name, PFID(fid));
+                       scrub->os_lf_repaired++;
+               } else {
+                       CWARN("%s: cannot rename for '%.*s' "DFID": rc = %d\n",
+                             osd_name(dev), namelen, name, PFID(fid), rc);
+               }
+       }
+
+       /* XXX: For MDT-objects, we can move them from /lost+found to namespace
+        *      visible place, such as the /ROOT/.lustre/lost+found, then LFSCK
+        *      can process them in furtuer. */
+
+       GOTO(put, rc);
+
+put:
+       if (rc < 0)
+               scrub->os_lf_failed++;
+       dput(child);
+       /* skip the failure to make the scanning to continue. */
+       return 0;
+}
+
 static int osd_ios_varfid_fill(void *buf, const char *name, int namelen,
                               loff_t offset, __u64 ino, unsigned d_type)
 {
@@ -1332,6 +1662,42 @@ static int osd_ios_varfid_fill(void *buf, const char *name, int namelen,
        RETURN(rc);
 }
 
+static int osd_ios_dl_fill(void *buf, const char *name, int namelen,
+                          loff_t offset, __u64 ino, unsigned d_type)
+{
+       struct osd_ios_filldir_buf *fill_buf = buf;
+       struct osd_device          *dev      = fill_buf->oifb_dev;
+       const struct osd_lf_map    *map;
+       struct dentry              *child;
+       int                         rc       = 0;
+       ENTRY;
+
+       /* skip any '.' started names */
+       if (name[0] == '.')
+               RETURN(0);
+
+       for (map = osd_dl_maps; map->olm_name != NULL; map++) {
+               if (strlen(map->olm_name) != namelen)
+                       continue;
+
+               if (strncmp(map->olm_name, name, namelen) == 0)
+                       break;
+       }
+
+       if (map->olm_name == NULL)
+               RETURN(0);
+
+       child = osd_ios_lookup_one_len(name, fill_buf->oifb_dentry, namelen);
+       if (IS_ERR(child))
+               RETURN(PTR_ERR(child));
+
+       rc = osd_ios_scan_one(fill_buf->oifb_info, dev, child->d_inode,
+                             &map->olm_fid, map->olm_flags);
+       dput(child);
+
+       RETURN(rc);
+}
+
 static int osd_ios_root_fill(void *buf, const char *name, int namelen,
                             loff_t offset, __u64 ino, unsigned d_type)
 {
@@ -1361,8 +1727,9 @@ static int osd_ios_root_fill(void *buf, const char *name, int namelen,
        if (IS_ERR(child))
                RETURN(PTR_ERR(child));
 
-       rc = osd_ios_scan_one(fill_buf->oifb_info, dev, child->d_inode,
-                             &map->olm_fid, map->olm_flags);
+       if (!(map->olm_flags & OLF_NO_OI))
+               rc = osd_ios_scan_one(fill_buf->oifb_info, dev, child->d_inode,
+                                     &map->olm_fid, map->olm_flags);
        if (rc == 0 && map->olm_flags & OLF_SCAN_SUBITEMS)
                rc = osd_ios_new_item(dev, child, map->olm_scandir,
                                      map->olm_filldir);
@@ -1375,7 +1742,13 @@ static int
 osd_ios_general_scan(struct osd_thread_info *info, struct osd_device *dev,
                     struct dentry *dentry, filldir_t filldir)
 {
-       struct osd_ios_filldir_buf    buf   = { info, dev, dentry };
+       struct osd_ios_filldir_buf    buf   = {
+#ifdef HAVE_DIR_CONTEXT
+                                               .ctx.actor = filldir,
+#endif
+                                               .oifb_info = info,
+                                               .oifb_dev = dev,
+                                               .oifb_dentry = dentry };
        struct file                  *filp  = &info->oti_it_ea.oie_file;
        struct inode                 *inode = dentry->d_inode;
        const struct file_operations *fops  = inode->i_fop;
@@ -1390,8 +1763,15 @@ osd_ios_general_scan(struct osd_thread_info *info, struct osd_device *dev,
        filp->f_mapping = inode->i_mapping;
        filp->f_op = fops;
        filp->private_data = NULL;
+       set_file_inode(filp, inode);
 
+#ifdef HAVE_DIR_CONTEXT
+       buf.ctx.pos = filp->f_pos;
+       rc = fops->iterate(filp, &buf.ctx);
+       filp->f_pos = buf.ctx.pos;
+#else
        rc = fops->readdir(filp, &buf, filldir);
+#endif
        fops->release(inode, filp);
 
        RETURN(rc);
@@ -1407,8 +1787,20 @@ osd_ios_ROOT_scan(struct osd_thread_info *info, struct osd_device *dev,
        int                rc;
        ENTRY;
 
-       /* It is existing MDT device. */
-       dev->od_handle_nolma = 1;
+       /* It is existing MDT0 device. We only allow the case of object without
+        * LMA to happen on the MDT0, which is usually for old 1.8 MDT. Then we
+        * can generate IGIF mode FID for the object and related OI mapping. If
+        * it is on other MDTs, then becuase file-level backup/restore, related
+        * OI mapping may be invalid already, we do not know which is the right
+        * FID for the object. We only allow IGIF objects to reside on the MDT0.
+        *
+        * XXX: For the case of object on non-MDT0 device with neither LMA nor
+        *      "fid" xattr, then something crashed. We cannot re-generate the
+        *      FID directly, instead, the OI scrub will scan the OI structure
+        *      and try to re-generate the LMA from the OI mapping. But if the
+        *      OI mapping crashed or lost also, then we have to give up under
+        *      double failure cases. */
+       scrub->os_convert_igif = 1;
        child = osd_ios_lookup_one_len(dot_lustre_name, dentry,
                                       strlen(dot_lustre_name));
        if (IS_ERR(child)) {
@@ -1419,13 +1811,41 @@ osd_ios_ROOT_scan(struct osd_thread_info *info, struct osd_device *dev,
                                osd_scrub_file_reset(scrub,
                                        LDISKFS_SB(osd_sb(dev))->s_es->s_uuid,
                                        SF_UPGRADE);
+                               sf->sf_internal_flags &= ~SIF_NO_HANDLE_OLD_FID;
                                rc = osd_scrub_file_store(scrub);
                        } else {
                                rc = 0;
                        }
                }
        } else {
-               rc = osd_ios_scan_one(info, dev, child->d_inode, NULL, 0);
+               /* For lustre-2.x (x <= 3), the ".lustre" has NO FID-in-LMA,
+                * so the client will get IGIF for the ".lustre" object when
+                * the MDT restart.
+                *
+                * From the OI scrub view, when the MDT upgrade to Lustre-2.4,
+                * it does not know whether there are some old clients cached
+                * the ".lustre" IGIF during the upgrading. Two choices:
+                *
+                * 1) Generate IGIF-in-LMA and IGIF-in-OI for the ".lustre".
+                *    It will allow the old connected clients to access the
+                *    ".lustre" with cached IGIF. But it will cause others
+                *    on the MDT failed to check "fid_is_dot_lustre()".
+                *
+                * 2) Use fixed FID {FID_SEQ_DOT_LUSTRE, FID_OID_DOT_LUSTRE, 0}
+                *    for ".lustre" in spite of whether there are some clients
+                *    cached the ".lustre" IGIF or not. It enables the check
+                *    "fid_is_dot_lustre()" on the MDT, although it will cause
+                *    that the old connected clients cannot access the ".lustre"
+                *    with the cached IGIF.
+                *
+                * Usually, it is rare case for the old connected clients
+                * to access the ".lustre" with cached IGIF. So we prefer
+                * to the solution 2). */
+               rc = osd_ios_scan_one(info, dev, child->d_inode,
+                                     &LU_DOT_LUSTRE_FID, 0);
+               if (rc == 0)
+                       rc = osd_ios_new_item(dev, child, osd_ios_general_scan,
+                                             osd_ios_dl_fill);
                dput(child);
        }
 
@@ -1436,10 +1856,19 @@ static int
 osd_ios_OBJECTS_scan(struct osd_thread_info *info, struct osd_device *dev,
                     struct dentry *dentry, filldir_t filldir)
 {
-       struct dentry *child;
-       int            rc;
+       struct osd_scrub  *scrub  = &dev->od_scrub;
+       struct scrub_file *sf     = &scrub->os_file;
+       struct dentry     *child;
+       int                rc;
        ENTRY;
 
+       if (unlikely(sf->sf_internal_flags & SIF_NO_HANDLE_OLD_FID)) {
+               sf->sf_internal_flags &= ~SIF_NO_HANDLE_OLD_FID;
+               rc = osd_scrub_file_store(scrub);
+               if (rc != 0)
+                       RETURN(rc);
+       }
+
        child = osd_ios_lookup_one_len(ADMIN_USR, dentry, strlen(ADMIN_USR));
        if (!IS_ERR(child)) {
                rc = osd_ios_scan_one(info, dev, child->d_inode, NULL, 0);
@@ -1468,13 +1897,17 @@ osd_ios_OBJECTS_scan(struct osd_thread_info *info, struct osd_device *dev,
 static int osd_initial_OI_scrub(struct osd_thread_info *info,
                                struct osd_device *dev)
 {
-       struct osd_ios_item *item    = NULL;
-       scandir_t            scandir = osd_ios_general_scan;
-       filldir_t            filldir = osd_ios_root_fill;
-       struct dentry       *dentry  = osd_sb(dev)->s_root;
-       int                  rc;
+       struct osd_ios_item     *item    = NULL;
+       scandir_t                scandir = osd_ios_general_scan;
+       filldir_t                filldir = osd_ios_root_fill;
+       struct dentry           *dentry  = osd_sb(dev)->s_root;
+       const struct osd_lf_map *map     = osd_lf_maps;
+       int                      rc;
        ENTRY;
 
+       /* Lookup IGIF in OI by force for initial OI scrub. */
+       dev->od_igif_inoi = 1;
+
        while (1) {
                rc = scandir(info, dev, dentry, filldir);
                if (item != NULL) {
@@ -1506,7 +1939,33 @@ static int osd_initial_OI_scrub(struct osd_thread_info *info,
                OBD_FREE_PTR(item);
        }
 
-       RETURN(rc);
+       if (rc != 0)
+               RETURN(rc);
+
+       /* There maybe the case that the object has been removed, but its OI
+        * mapping is still in the OI file, such as the "CATALOGS" after MDT
+        * file-level backup/restore. So here cleanup the stale OI mappings. */
+       while (map->olm_name != NULL) {
+               struct dentry *child;
+
+               if (fid_is_zero(&map->olm_fid)) {
+                       map++;
+                       continue;
+               }
+
+               child = osd_ios_lookup_one_len(map->olm_name,
+                                              osd_sb(dev)->s_root,
+                                              strlen(map->olm_name));
+               if (!IS_ERR(child))
+                       dput(child);
+               else if (PTR_ERR(child) == -ENOENT)
+                       osd_scrub_refresh_mapping(info, dev, &map->olm_fid,
+                                                 NULL, DTO_INDEX_DELETE,
+                                                 true, 0);
+               map++;
+       }
+
+       RETURN(0);
 }
 
 char *osd_lf_fid2name(const struct lu_fid *fid)
@@ -1535,6 +1994,7 @@ static int do_osd_scrub_start(struct osd_device *dev, __u32 flags)
        struct osd_scrub     *scrub  = &dev->od_scrub;
        struct ptlrpc_thread *thread = &scrub->os_thread;
        struct l_wait_info    lwi    = { 0 };
+       struct task_struct   *task;
        int                   rc;
        ENTRY;
 
@@ -1558,9 +2018,10 @@ again:
 
        scrub->os_start_flags = flags;
        thread_set_flags(thread, 0);
-       rc = cfs_create_thread(osd_scrub_main, dev, 0);
-       if (rc < 0) {
-               CERROR("%.16s: cannot start iteration thread, rc = %d\n",
+       task = kthread_run(osd_scrub_main, dev, "OI_scrub");
+       if (IS_ERR(task)) {
+               rc = PTR_ERR(task);
+               CERROR("%.16s: cannot start iteration thread: rc = %d\n",
                       LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name, rc);
                RETURN(rc);
        }
@@ -1595,7 +2056,7 @@ static void do_osd_scrub_stop(struct osd_scrub *scrub)
        if (!thread_is_init(thread) && !thread_is_stopped(thread)) {
                thread_set_flags(thread, SVC_STOPPING);
                spin_unlock(&scrub->os_lock);
-               cfs_waitq_broadcast(&thread->t_ctl_waitq);
+               wake_up_all(&thread->t_ctl_waitq);
                l_wait_event(thread->t_ctl_waitq,
                             thread_is_stopped(thread),
                             &lwi);
@@ -1629,6 +2090,8 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
        struct ldiskfs_super_block *es     = LDISKFS_SB(sb)->s_es;
        struct lvfs_run_ctxt        saved;
        struct file                *filp;
+       struct inode               *inode;
+       struct lu_fid              *fid    = &info->oti_fid;
        int                         dirty  = 0;
        int                         rc     = 0;
        ENTRY;
@@ -1639,25 +2102,50 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
        ctxt->pwd = dev->od_mnt->mnt_root;
        ctxt->fs = get_ds();
 
-       cfs_waitq_init(&scrub->os_thread.t_ctl_waitq);
+       init_waitqueue_head(&scrub->os_thread.t_ctl_waitq);
        init_rwsem(&scrub->os_rwsem);
        spin_lock_init(&scrub->os_lock);
        CFS_INIT_LIST_HEAD(&scrub->os_inconsistent_items);
 
-       push_ctxt(&saved, ctxt, NULL);
+       push_ctxt(&saved, ctxt);
        filp = filp_open(osd_scrub_name, O_RDWR | O_CREAT, 0644);
-       if (IS_ERR(filp))
+       if (IS_ERR(filp)) {
+               pop_ctxt(&saved, ctxt);
                RETURN(PTR_ERR(filp));
+       }
 
-       scrub->os_inode = igrab(filp->f_dentry->d_inode);
+       inode = filp->f_dentry->d_inode;
+       /* 'What the @fid is' is not imporatant, because the object
+        * has no OI mapping, and only is visible inside the OSD.*/
+       lu_igif_build(fid, inode->i_ino, inode->i_generation);
+       rc = osd_ea_fid_set(info, inode, fid, LMAC_NOT_IN_OI, 0);
+       if (rc != 0) {
+               filp_close(filp, 0);
+               pop_ctxt(&saved, ctxt);
+               RETURN(rc);
+       }
+
+       scrub->os_inode = igrab(inode);
        filp_close(filp, 0);
-       pop_ctxt(&saved, ctxt, NULL);
-       ldiskfs_set_inode_state(scrub->os_inode,
-                               LDISKFS_STATE_LUSTRE_NO_OI);
+       pop_ctxt(&saved, ctxt);
 
        rc = osd_scrub_file_load(scrub);
        if (rc == -ENOENT) {
                osd_scrub_file_init(scrub, es->s_uuid);
+               /* If the "/O" dir does not exist when mount (indicated by
+                * osd_device::od_maybe_new), neither for the "/OI_scrub",
+                * then it is quite probably that the device is a new one,
+                * under such case, mark it as SIF_NO_HANDLE_OLD_FID.
+                *
+                * For the rare case that "/O" and "OI_scrub" both lost on
+                * an old device, it can be found and cleared later.
+                *
+                * For the system with "SIF_NO_HANDLE_OLD_FID", we do not
+                * need to check "filter_fid_old" and to convert it to
+                * "filter_fid" for each object, and all the IGIF should
+                * have their FID mapping in OI files already. */
+               if (dev->od_maybe_new)
+                       sf->sf_internal_flags = SIF_NO_HANDLE_OLD_FID;
                dirty = 1;
        } else if (rc != 0) {
                RETURN(rc);
@@ -1688,14 +2176,45 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
                RETURN(rc);
 
        rc = osd_initial_OI_scrub(info, dev);
-       if (rc == 0 && !dev->od_noscrub &&
-           ((sf->sf_status == SS_PAUSED) ||
-            (sf->sf_status == SS_CRASHED &&
-             sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT | SF_UPGRADE |
-                             SF_AUTO)) ||
-            (sf->sf_status == SS_INIT &&
-             sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT | SF_UPGRADE))))
-               rc = osd_scrub_start(dev);
+       if (rc == 0) {
+               if (sf->sf_flags & SF_UPGRADE ||
+                   !(sf->sf_internal_flags & SIF_NO_HANDLE_OLD_FID ||
+                     sf->sf_success_count > 0)) {
+                       dev->od_igif_inoi = 0;
+                       dev->od_check_ff = dev->od_is_ost;
+               } else {
+                       dev->od_igif_inoi = 1;
+                       dev->od_check_ff = 0;
+               }
+
+               if (sf->sf_flags & SF_INCONSISTENT)
+                       /* The 'od_igif_inoi' will be set under the
+                        * following cases:
+                        * 1) new created system, or
+                        * 2) restored from file-level backup, or
+                        * 3) the upgrading completed.
+                        *
+                        * The 'od_igif_inoi' may be cleared by OI scrub
+                        * later if found that the system is upgrading. */
+                       dev->od_igif_inoi = 1;
+
+               if (!dev->od_noscrub &&
+                   ((sf->sf_status == SS_PAUSED) ||
+                    (sf->sf_status == SS_CRASHED &&
+                     sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT |
+                                     SF_UPGRADE | SF_AUTO)) ||
+                    (sf->sf_status == SS_INIT &&
+                     sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT |
+                                     SF_UPGRADE))))
+                       rc = osd_scrub_start(dev);
+       }
+
+       /* it is possible that dcache entries may keep objects after they are
+        * deleted by OSD. While it looks safe this can cause object data to
+        * stay until umount causing failures in tests calculating free space,
+        * e.g. replay-ost-single. Since those dcache entries are not used
+        * anymore let's just free them after use here */
+       shrink_dcache_sb(sb);
 
        RETURN(rc);
 }
@@ -1741,7 +2260,6 @@ static struct dt_it *osd_otable_it_init(const struct lu_env *env,
 
        dev->od_otable_it = it;
        it->ooi_dev = dev;
-       it->ooi_pid = cfs_curproc_pid();
        it->ooi_cache.ooc_consumer_idx = -1;
        if (flags & DOIF_OUTUSED)
                it->ooi_used_outside = 1;
@@ -1756,6 +2274,13 @@ static struct dt_it *osd_otable_it_init(const struct lu_env *env,
                        start |= SS_CLEAR_FAILOUT;
        }
 
+       if (valid & DOIV_DRYRUN) {
+               if (flags & DOIF_DRYRUN)
+                       start |= SS_SET_DRYRUN;
+               else
+                       start |= SS_CLEAR_DRYRUN;
+       }
+
        rc = do_osd_scrub_start(dev, start);
        if (rc < 0 && rc != -EALREADY) {
                dev->od_otable_it = NULL;
@@ -1793,30 +2318,8 @@ static int osd_otable_it_get(const struct lu_env *env,
        return 0;
 }
 
-/**
- * It is hack here:
- *
- * Sometimes the otable-based iteration driver (LFSCK) may be blocked in OSD
- * layer when someone wants to stop/pause the iteration. Under such case, we
- * need some mechanism to notify the event and wakeup the blocker.
- */
 static void osd_otable_it_put(const struct lu_env *env, struct dt_it *di)
 {
-       struct osd_otable_it *it  = (struct osd_otable_it *)di;
-       struct osd_device    *dev = it->ooi_dev;
-
-       /* od_otable_mutex: prevent curcurrent init/fini */
-       mutex_lock(&dev->od_otable_mutex);
-       if (it->ooi_pid == cfs_curproc_pid()) {
-               dev->od_scrub.os_paused = 1;
-       } else {
-               struct ptlrpc_thread *thread = &dev->od_scrub.os_thread;
-
-               it->ooi_stopping = 1;
-               if (it->ooi_waiting)
-                       cfs_waitq_broadcast(&thread->t_ctl_waitq);
-       }
-       mutex_unlock(&dev->od_otable_mutex);
 }
 
 static inline int
@@ -1824,7 +2327,7 @@ osd_otable_it_wakeup(struct osd_scrub *scrub, struct osd_otable_it *it)
 {
        spin_lock(&scrub->os_lock);
        if (it->ooi_cache.ooc_pos_preload < scrub->os_pos_current ||
-           scrub->os_waiting || it->ooi_stopping ||
+           scrub->os_waiting ||
            !thread_is_running(&scrub->os_thread))
                it->ooi_waiting = 0;
        else
@@ -1868,7 +2371,7 @@ again:
        if (scrub->os_waiting && osd_scrub_has_window(scrub, ooc)) {
                spin_lock(&scrub->os_lock);
                scrub->os_waiting = 0;
-               cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
+               wake_up_all(&scrub->os_thread.t_ctl_waitq);
                spin_unlock(&scrub->os_lock);
        }
 
@@ -1880,9 +2383,6 @@ again:
        if (!thread_is_running(thread) && !it->ooi_used_outside)
                RETURN(1);
 
-       if (it->ooi_stopping)
-               RETURN(0);
-
        rc = osd_otable_it_preload(env, it);
        if (rc >= 0)
                goto again;
@@ -1926,12 +2426,10 @@ static __u64 osd_otable_it_store(const struct lu_env *env,
        struct osd_otable_cache *ooc = &it->ooi_cache;
        __u64                    hash;
 
-       if (it->ooi_user_ready)
-               hash = ooc->ooc_pos_preload;
-       else if (likely(ooc->ooc_consumer_idx != -1))
+       if (it->ooi_user_ready && ooc->ooc_consumer_idx != -1)
                hash = ooc->ooc_cache[ooc->ooc_consumer_idx].oic_lid.oii_ino;
        else
-               hash = 0;
+               hash = ooc->ooc_pos_preload;
        return hash;
 }
 
@@ -1955,16 +2453,13 @@ static int osd_otable_it_load(const struct lu_env *env,
        if (hash > OSD_OTABLE_MAX_HASH)
                hash = OSD_OTABLE_MAX_HASH;
 
-       /* Skip the one that has been processed last time. */
-       if (ooc->ooc_pos_preload > hash)
-               ooc->ooc_pos_preload = hash;
-
+       ooc->ooc_pos_preload = hash;
        if (ooc->ooc_pos_preload <= LDISKFS_FIRST_INO(osd_sb(dev)))
                ooc->ooc_pos_preload = LDISKFS_FIRST_INO(osd_sb(dev)) + 1;
 
        it->ooi_user_ready = 1;
        if (!scrub->os_full_speed)
-               cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
+               wake_up_all(&scrub->os_thread.t_ctl_waitq);
 
        /* Unplug OSD layer iteration by the first next() call. */
        rc = osd_otable_it_next(env, (struct dt_it *)it);
@@ -2026,7 +2521,7 @@ int osd_oii_insert(struct osd_device *dev, struct osd_idmap_cache *oic,
        spin_unlock(&scrub->os_lock);
 
        if (wakeup != 0)
-               cfs_waitq_broadcast(&thread->t_ctl_waitq);
+               wake_up_all(&thread->t_ctl_waitq);
 
        RETURN(0);
 }
@@ -2074,137 +2569,116 @@ static const char *scrub_flags_names[] = {
 
 static const char *scrub_param_names[] = {
        "failout",
+       "dryrun",
        NULL
 };
 
-static int scrub_bits_dump(char **buf, int *len, int bits, const char *names[],
+static int scrub_bits_dump(struct seq_file *m, int bits, const char *names[],
                           const char *prefix)
 {
-       int save = *len;
        int flag;
        int rc;
        int i;
 
-       rc = snprintf(*buf, *len, "%s:%c", prefix, bits != 0 ? ' ' : '\n');
-       if (rc <= 0)
-               return -ENOSPC;
+       rc = seq_printf(m, "%s:%c", prefix, bits != 0 ? ' ' : '\n');
+       if (rc < 0)
+               return rc;
 
-       *buf += rc;
-       *len -= rc;
        for (i = 0, flag = 1; bits != 0; i++, flag = 1 << i) {
                if (flag & bits) {
                        bits &= ~flag;
-                       rc = snprintf(*buf, *len, "%s%c", names[i],
-                                     bits != 0 ? ',' : '\n');
-                       if (rc <= 0)
-                               return -ENOSPC;
-
-                       *buf += rc;
-                       *len -= rc;
+                       rc = seq_printf(m, "%s%c", names[i],
+                                       bits != 0 ? ',' : '\n');
+                       if (rc < 0)
+                               return rc;
                }
        }
-       return save - *len;
+       return 0;
 }
 
-static int scrub_time_dump(char **buf, int *len, __u64 time, const char *prefix)
+static int scrub_time_dump(struct seq_file *m, __u64 time, const char *prefix)
 {
        int rc;
 
        if (time != 0)
-               rc = snprintf(*buf, *len, "%s: "LPU64" seconds\n", prefix,
+               rc = seq_printf(m, "%s: "LPU64" seconds\n", prefix,
                              cfs_time_current_sec() - time);
        else
-               rc = snprintf(*buf, *len, "%s: N/A\n", prefix);
-       if (rc <= 0)
-               return -ENOSPC;
-
-       *buf += rc;
-       *len -= rc;
+               rc = seq_printf(m, "%s: N/A\n", prefix);
        return rc;
 }
 
-static int scrub_pos_dump(char **buf, int *len, __u64 pos, const char *prefix)
+static int scrub_pos_dump(struct seq_file *m, __u64 pos, const char *prefix)
 {
        int rc;
 
        if (pos != 0)
-               rc = snprintf(*buf, *len, "%s: "LPU64"\n", prefix, pos);
+               rc = seq_printf(m, "%s: "LPU64"\n", prefix, pos);
        else
-               rc = snprintf(*buf, *len, "%s: N/A\n", prefix);
-       if (rc <= 0)
-               return -ENOSPC;
-
-       *buf += rc;
-       *len -= rc;
+               rc = seq_printf(m, "%s: N/A\n", prefix);
        return rc;
 }
 
-int osd_scrub_dump(struct osd_device *dev, char *buf, int len)
+int osd_scrub_dump(struct seq_file *m, struct osd_device *dev)
 {
        struct osd_scrub  *scrub   = &dev->od_scrub;
        struct scrub_file *sf      = &scrub->os_file;
        __u64              checked;
        __u64              speed;
-       int                save    = len;
-       int                ret     = -ENOSPC;
        int                rc;
 
        down_read(&scrub->os_rwsem);
-       rc = snprintf(buf, len,
-                     "name: OI_scrub\n"
-                     "magic: 0x%x\n"
-                     "oi_files: %d\n"
-                     "status: %s\n",
-                     sf->sf_magic, (int)sf->sf_oi_count,
-                     scrub_status_names[sf->sf_status]);
-       if (rc <= 0)
+       rc = seq_printf(m, "name: OI_scrub\n"
+                       "magic: 0x%x\n"
+                       "oi_files: %d\n"
+                       "status: %s\n",
+                       sf->sf_magic, (int)sf->sf_oi_count,
+                       scrub_status_names[sf->sf_status]);
+       if (rc < 0)
                goto out;
 
-       buf += rc;
-       len -= rc;
-       rc = scrub_bits_dump(&buf, &len, sf->sf_flags, scrub_flags_names,
+       rc = scrub_bits_dump(m, sf->sf_flags, scrub_flags_names,
                             "flags");
        if (rc < 0)
                goto out;
 
-       rc = scrub_bits_dump(&buf, &len, sf->sf_param, scrub_param_names,
+       rc = scrub_bits_dump(m, sf->sf_param, scrub_param_names,
                             "param");
        if (rc < 0)
                goto out;
 
-       rc = scrub_time_dump(&buf, &len, sf->sf_time_last_complete,
+       rc = scrub_time_dump(m, sf->sf_time_last_complete,
                             "time_since_last_completed");
        if (rc < 0)
                goto out;
 
-       rc = scrub_time_dump(&buf, &len, sf->sf_time_latest_start,
+       rc = scrub_time_dump(m, sf->sf_time_latest_start,
                             "time_since_latest_start");
        if (rc < 0)
                goto out;
 
-       rc = scrub_time_dump(&buf, &len, sf->sf_time_last_checkpoint,
+       rc = scrub_time_dump(m, sf->sf_time_last_checkpoint,
                             "time_since_last_checkpoint");
        if (rc < 0)
                goto out;
 
-       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_latest_start,
+       rc = scrub_pos_dump(m, sf->sf_pos_latest_start,
                            "latest_start_position");
        if (rc < 0)
                goto out;
 
-       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_last_checkpoint,
+       rc = scrub_pos_dump(m, sf->sf_pos_last_checkpoint,
                            "last_checkpoint_position");
        if (rc < 0)
                goto out;
 
-       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_first_inconsistent,
+       rc = scrub_pos_dump(m, sf->sf_pos_first_inconsistent,
                            "first_failure_position");
        if (rc < 0)
                goto out;
 
        checked = sf->sf_items_checked + scrub->os_new_checked;
-       rc = snprintf(buf, len,
-                     "checked: "LPU64"\n"
+       rc = seq_printf(m, "checked: "LPU64"\n"
                      "updated: "LPU64"\n"
                      "failed: "LPU64"\n"
                      "prior_updated: "LPU64"\n"
@@ -2214,16 +2688,14 @@ int osd_scrub_dump(struct osd_device *dev, char *buf, int len)
                      checked, sf->sf_items_updated, sf->sf_items_failed,
                      sf->sf_items_updated_prior, sf->sf_items_noscrub,
                      sf->sf_items_igif, sf->sf_success_count);
-       if (rc <= 0)
+       if (rc < 0)
                goto out;
 
-       buf += rc;
-       len -= rc;
        speed = checked;
        if (thread_is_running(&scrub->os_thread)) {
                cfs_duration_t duration = cfs_time_current() -
                                          scrub->os_time_last_checkpoint;
-               __u64 new_checked = scrub->os_new_checked * CFS_HZ;
+               __u64 new_checked = scrub->os_new_checked * HZ;
                __u32 rtime = sf->sf_run_time +
                              cfs_duration_sec(duration + HALF_SEC);
 
@@ -2231,30 +2703,31 @@ int osd_scrub_dump(struct osd_device *dev, char *buf, int len)
                        do_div(new_checked, duration);
                if (rtime != 0)
                        do_div(speed, rtime);
-               rc = snprintf(buf, len,
-                             "run_time: %u seconds\n"
+               rc = seq_printf(m, "run_time: %u seconds\n"
                              "average_speed: "LPU64" objects/sec\n"
                              "real-time_speed: "LPU64" objects/sec\n"
-                             "current_position: %u\n",
-                             rtime, speed, new_checked, scrub->os_pos_current);
+                             "current_position: %u\n"
+                             "lf_scanned: "LPU64"\n"
+                             "lf_reparied: "LPU64"\n"
+                             "lf_failed: "LPU64"\n",
+                             rtime, speed, new_checked, scrub->os_pos_current,
+                             scrub->os_lf_scanned, scrub->os_lf_repaired,
+                             scrub->os_lf_failed);
        } else {
                if (sf->sf_run_time != 0)
                        do_div(speed, sf->sf_run_time);
-               rc = snprintf(buf, len,
-                             "run_time: %u seconds\n"
+               rc = seq_printf(m, "run_time: %u seconds\n"
                              "average_speed: "LPU64" objects/sec\n"
                              "real-time_speed: N/A\n"
-                             "current_position: N/A\n",
-                             sf->sf_run_time, speed);
+                             "current_position: N/A\n"
+                             "lf_scanned: "LPU64"\n"
+                             "lf_reparied: "LPU64"\n"
+                             "lf_failed: "LPU64"\n",
+                             sf->sf_run_time, speed, scrub->os_lf_scanned,
+                             scrub->os_lf_repaired, scrub->os_lf_failed);
        }
-       if (rc <= 0)
-               goto out;
-
-       buf += rc;
-       len -= rc;
-       ret = save - len;
 
 out:
        up_read(&scrub->os_rwsem);
-       return ret;
+       return (rc < 0 ? -ENOSPC : 0);
 }