Whamcloud - gitweb
LU-5710 all: second batch of corrected typos and grammar errors
[fs/lustre-release.git] / lustre / obdclass / dt_object.c
index 11a8984..b970e11 100644 (file)
@@ -27,7 +27,7 @@
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2012, Whamcloud, Inc.
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -49,7 +49,7 @@
 /* fid_be_to_cpu() */
 #include <lustre_fid.h>
 
-#include <lquota.h>
+#include <lustre_quota.h>
 
 /* context key constructor/destructor: dt_global_key_init, dt_global_key_fini */
 LU_KEY_INIT(dt_global, struct dt_thread_info);
@@ -60,20 +60,19 @@ struct lu_context_key dt_key = {
         .lct_init = dt_global_key_init,
         .lct_fini = dt_global_key_fini
 };
-EXPORT_SYMBOL(dt_key);
 
 /* no lock is necessary to protect the list, because call-backs
  * are added during system startup. Please refer to "struct dt_device".
  */
 void dt_txn_callback_add(struct dt_device *dev, struct dt_txn_callback *cb)
 {
-        cfs_list_add(&cb->dtc_linkage, &dev->dd_txn_callbacks);
+       list_add(&cb->dtc_linkage, &dev->dd_txn_callbacks);
 }
 EXPORT_SYMBOL(dt_txn_callback_add);
 
 void dt_txn_callback_del(struct dt_device *dev, struct dt_txn_callback *cb)
 {
-        cfs_list_del_init(&cb->dtc_linkage);
+       list_del_init(&cb->dtc_linkage);
 }
 EXPORT_SYMBOL(dt_txn_callback_del);
 
@@ -86,7 +85,7 @@ int dt_txn_hook_start(const struct lu_env *env,
         if (th->th_local)
                 return 0;
 
-        cfs_list_for_each_entry(cb, &dev->dd_txn_callbacks, dtc_linkage) {
+       list_for_each_entry(cb, &dev->dd_txn_callbacks, dtc_linkage) {
                 if (cb->dtc_txn_start == NULL ||
                     !(cb->dtc_tag & env->le_ctx.lc_tags))
                         continue;
@@ -107,7 +106,7 @@ int dt_txn_hook_stop(const struct lu_env *env, struct thandle *txn)
         if (txn->th_local)
                 return 0;
 
-        cfs_list_for_each_entry(cb, &dev->dd_txn_callbacks, dtc_linkage) {
+       list_for_each_entry(cb, &dev->dd_txn_callbacks, dtc_linkage) {
                 if (cb->dtc_txn_stop == NULL ||
                     !(cb->dtc_tag & env->le_ctx.lc_tags))
                         continue;
@@ -121,24 +120,23 @@ EXPORT_SYMBOL(dt_txn_hook_stop);
 
 void dt_txn_hook_commit(struct thandle *txn)
 {
-        struct dt_txn_callback *cb;
+       struct dt_txn_callback *cb;
 
-        if (txn->th_local)
-                return;
+       if (txn->th_local)
+               return;
 
-        cfs_list_for_each_entry(cb, &txn->th_dev->dd_txn_callbacks,
-                                dtc_linkage) {
-                if (cb->dtc_txn_commit)
-                        cb->dtc_txn_commit(txn, cb->dtc_cookie);
-        }
+       list_for_each_entry(cb, &txn->th_dev->dd_txn_callbacks,
+                           dtc_linkage) {
+               if (cb->dtc_txn_commit)
+                       cb->dtc_txn_commit(txn, cb->dtc_cookie);
+       }
 }
 EXPORT_SYMBOL(dt_txn_hook_commit);
 
 int dt_device_init(struct dt_device *dev, struct lu_device_type *t)
 {
-
-        CFS_INIT_LIST_HEAD(&dev->dd_txn_callbacks);
-        return lu_device_init(&dev->dd_lu_dev, t);
+       INIT_LIST_HEAD(&dev->dd_txn_callbacks);
+       return lu_device_init(&dev->dd_lu_dev, t);
 }
 EXPORT_SYMBOL(dt_device_init);
 
@@ -205,38 +203,41 @@ EXPORT_SYMBOL(dt_mode_to_dft);
 int dt_lookup_dir(const struct lu_env *env, struct dt_object *dir,
                   const char *name, struct lu_fid *fid)
 {
-        if (dt_try_as_dir(env, dir))
-                return dt_lookup(env, dir, (struct dt_rec *)fid,
-                                 (const struct dt_key *)name, BYPASS_CAPA);
-        return -ENOTDIR;
+       if (dt_try_as_dir(env, dir))
+               return dt_lookup(env, dir, (struct dt_rec *)fid,
+                                (const struct dt_key *)name);
+       return -ENOTDIR;
 }
 EXPORT_SYMBOL(dt_lookup_dir);
 
 /* this differs from dt_locate by top_dev as parameter
  * but not one from lu_site */
 struct dt_object *dt_locate_at(const struct lu_env *env,
-                              struct dt_device *dev, const struct lu_fid *fid,
-                              struct lu_device *top_dev)
+                              struct dt_device *dev,
+                              const struct lu_fid *fid,
+                              struct lu_device *top_dev,
+                              const struct lu_object_conf *conf)
 {
-       struct lu_object *lo, *n;
-       ENTRY;
+       struct lu_object *lo;
+       struct lu_object *n;
 
-       lo = lu_object_find_at(env, top_dev, fid, NULL);
+       lo = lu_object_find_at(env, top_dev, fid, conf);
        if (IS_ERR(lo))
-               return (void *)lo;
+               return ERR_PTR(PTR_ERR(lo));
 
        LASSERT(lo != NULL);
 
-       cfs_list_for_each_entry(n, &lo->lo_header->loh_layers, lo_linkage) {
+       list_for_each_entry(n, &lo->lo_header->loh_layers, lo_linkage) {
                if (n->lo_dev == &dev->dd_lu_dev)
                        return container_of0(n, struct dt_object, do_lu);
        }
+
        return ERR_PTR(-ENOENT);
 }
 EXPORT_SYMBOL(dt_locate_at);
 
 /**
- * find a object named \a entry in given \a dfh->dfh_o directory.
+ * find an object named \a entry in given \a dfh->dfh_o directory.
  */
 static int dt_find_entry(const struct lu_env *env, const char *entry, void *data)
 {
@@ -286,30 +287,28 @@ int dt_path_parser(const struct lu_env *env,
         return rc;
 }
 
-static struct dt_object *dt_store_resolve(const struct lu_env *env,
-                                          struct dt_device *dt,
-                                          const char *path,
-                                          struct lu_fid *fid)
+struct dt_object *
+dt_store_resolve(const struct lu_env *env, struct dt_device *dt,
+                const char *path, struct lu_fid *fid)
 {
        struct dt_thread_info *info = dt_info(env);
        struct dt_find_hint   *dfh = &info->dti_dfh;
        struct dt_object      *obj;
-       char                  *local = info->dti_buf;
        int                    result;
 
 
         dfh->dfh_dt = dt;
         dfh->dfh_fid = fid;
 
-        strncpy(local, path, DT_MAX_PATH);
-        local[DT_MAX_PATH - 1] = '\0';
+       strlcpy(info->dti_buf, path, sizeof(info->dti_buf));
 
         result = dt->dd_ops->dt_root_get(env, dt, fid);
         if (result == 0) {
                 obj = dt_locate(env, dt, fid);
                 if (!IS_ERR(obj)) {
                         dfh->dfh_o = obj;
-                        result = dt_path_parser(env, local, dt_find_entry, dfh);
+                       result = dt_path_parser(env, info->dti_buf,
+                                               dt_find_entry, dfh);
                         if (result != 0)
                                 obj = ERR_PTR(result);
                         else
@@ -364,7 +363,6 @@ struct dt_object *dt_store_open(const struct lu_env *env,
         }
         return file;
 }
-EXPORT_SYMBOL(dt_store_open);
 
 struct dt_object *dt_find_or_create(const struct lu_env *env,
                                     struct dt_device *dt,
@@ -450,8 +448,8 @@ void dt_global_fini(void)
 int dt_read(const struct lu_env *env, struct dt_object *dt,
             struct lu_buf *buf, loff_t *pos)
 {
-        LASSERTF(dt != NULL, "dt is NULL when we want to read record\n");
-        return dt->do_body_ops->dbo_read(env, dt, buf, pos, BYPASS_CAPA);
+       LASSERTF(dt != NULL, "dt is NULL when we want to read record\n");
+       return dt->do_body_ops->dbo_read(env, dt, buf, pos);
 }
 EXPORT_SYMBOL(dt_read);
 
@@ -471,35 +469,31 @@ EXPORT_SYMBOL(dt_read);
 int dt_record_read(const struct lu_env *env, struct dt_object *dt,
                    struct lu_buf *buf, loff_t *pos)
 {
-        int rc;
-
-        LASSERTF(dt != NULL, "dt is NULL when we want to read record\n");
+       ssize_t size;
 
-        rc = dt->do_body_ops->dbo_read(env, dt, buf, pos, BYPASS_CAPA);
+       LASSERTF(dt != NULL, "dt is NULL when we want to read record\n");
 
-        if (rc == buf->lb_len)
-                rc = 0;
-        else if (rc >= 0)
-                rc = -EFAULT;
-        return rc;
+       size = dt->do_body_ops->dbo_read(env, dt, buf, pos);
+       if (size < 0)
+               return size;
+       return (size == (ssize_t)buf->lb_len) ? 0 : -EFAULT;
 }
 EXPORT_SYMBOL(dt_record_read);
 
 int dt_record_write(const struct lu_env *env, struct dt_object *dt,
                     const struct lu_buf *buf, loff_t *pos, struct thandle *th)
 {
-        int rc;
+       ssize_t size;
 
-        LASSERTF(dt != NULL, "dt is NULL when we want to write record\n");
-        LASSERT(th != NULL);
-        LASSERT(dt->do_body_ops);
-        LASSERT(dt->do_body_ops->dbo_write);
-        rc = dt->do_body_ops->dbo_write(env, dt, buf, pos, th, BYPASS_CAPA, 1);
-        if (rc == buf->lb_len)
-                rc = 0;
-        else if (rc >= 0)
-                rc = -EFAULT;
-        return rc;
+       LASSERTF(dt != NULL, "dt is NULL when we want to write record\n");
+       LASSERT(th != NULL);
+       LASSERT(dt->do_body_ops);
+       LASSERT(dt->do_body_ops->dbo_write);
+
+       size = dt->do_body_ops->dbo_write(env, dt, buf, pos, th, 1);
+       if (size < 0)
+               return size;
+       return (size == (ssize_t)buf->lb_len) ? 0 : -EFAULT;
 }
 EXPORT_SYMBOL(dt_record_write);
 
@@ -528,7 +522,7 @@ void dt_version_set(const struct lu_env *env, struct dt_object *o,
         vbuf.lb_buf = &version;
         vbuf.lb_len = sizeof(version);
 
-        rc = dt_xattr_set(env, o, &vbuf, xname, 0, th, BYPASS_CAPA);
+       rc = dt_xattr_set(env, o, &vbuf, xname, 0, th);
         if (rc < 0)
                 CDEBUG(D_INODE, "Can't set version, rc %d\n", rc);
         return;
@@ -545,7 +539,7 @@ dt_obj_version_t dt_version_get(const struct lu_env *env, struct dt_object *o)
         LASSERT(o);
         vbuf.lb_buf = &version;
         vbuf.lb_len = sizeof(version);
-        rc = dt_xattr_get(env, o, &vbuf, xname, BYPASS_CAPA);
+       rc = dt_xattr_get(env, o, &vbuf, xname);
         if (rc != sizeof(version)) {
                 CDEBUG(D_INODE, "Can't get version, rc %d\n", rc);
                 version = 0;
@@ -564,6 +558,28 @@ EXPORT_SYMBOL(dt_directory_features);
 const struct dt_index_features dt_otable_features;
 EXPORT_SYMBOL(dt_otable_features);
 
+/* lfsck orphan */
+const struct dt_index_features dt_lfsck_orphan_features = {
+       .dif_flags              = 0,
+       .dif_keysize_min        = sizeof(struct lu_fid),
+       .dif_keysize_max        = sizeof(struct lu_fid),
+       .dif_recsize_min        = sizeof(struct lu_orphan_rec),
+       .dif_recsize_max        = sizeof(struct lu_orphan_rec),
+       .dif_ptrsize            = 4
+};
+EXPORT_SYMBOL(dt_lfsck_orphan_features);
+
+/* lfsck */
+const struct dt_index_features dt_lfsck_features = {
+       .dif_flags              = DT_IND_UPDATE,
+       .dif_keysize_min        = sizeof(struct lu_fid),
+       .dif_keysize_max        = sizeof(struct lu_fid),
+       .dif_recsize_min        = sizeof(__u8),
+       .dif_recsize_max        = sizeof(__u8),
+       .dif_ptrsize            = 4
+};
+EXPORT_SYMBOL(dt_lfsck_features);
+
 /* accounting indexes */
 const struct dt_index_features dt_acct_features = {
        .dif_flags              = DT_IND_UPDATE,
@@ -598,3 +614,435 @@ const struct dt_index_features dt_quota_slv_features = {
        .dif_ptrsize            = 4
 };
 EXPORT_SYMBOL(dt_quota_slv_features);
+
+/* helper function returning what dt_index_features structure should be used
+ * based on the FID sequence. This is used by OBD_IDX_READ RPC */
+static inline const struct dt_index_features *dt_index_feat_select(__u64 seq,
+                                                                  __u32 mode)
+{
+       if (seq == FID_SEQ_QUOTA_GLB) {
+               /* global quota index */
+               if (!S_ISREG(mode))
+                       /* global quota index should be a regular file */
+                       return ERR_PTR(-ENOENT);
+               return &dt_quota_glb_features;
+       } else if (seq == FID_SEQ_QUOTA) {
+               /* quota slave index */
+               if (!S_ISREG(mode))
+                       /* slave index should be a regular file */
+                       return ERR_PTR(-ENOENT);
+               return &dt_quota_slv_features;
+       } else if (seq == FID_SEQ_LAYOUT_RBTREE){
+               return &dt_lfsck_orphan_features;
+       } else if (seq >= FID_SEQ_NORMAL) {
+               /* object is part of the namespace, verify that it is a
+                * directory */
+               if (!S_ISDIR(mode))
+                       /* sorry, we can only deal with directory */
+                       return ERR_PTR(-ENOTDIR);
+               return &dt_directory_features;
+       }
+
+       return ERR_PTR(-EOPNOTSUPP);
+}
+
+/*
+ * Fill a lu_idxpage with key/record pairs read for transfer via OBD_IDX_READ
+ * RPC
+ *
+ * \param env - is the environment passed by the caller
+ * \param lp  - is a pointer to the lu_page to fill
+ * \param nob - is the maximum number of bytes that should be copied
+ * \param iops - is the index operation vector associated with the index object
+ * \param it   - is a pointer to the current iterator
+ * \param attr - is the index attribute to pass to iops->rec()
+ * \param arg  - is a pointer to the idx_info structure
+ */
+static int dt_index_page_build(const struct lu_env *env, union lu_page *lp,
+                              size_t nob, const struct dt_it_ops *iops,
+                              struct dt_it *it, __u32 attr, void *arg)
+{
+       struct idx_info         *ii = (struct idx_info *)arg;
+       struct lu_idxpage       *lip = &lp->lp_idx;
+       char                    *entry;
+       size_t                   size;
+       int                      rc;
+       ENTRY;
+
+       if (nob < LIP_HDR_SIZE)
+               return -EINVAL;
+
+       /* initialize the header of the new container */
+       memset(lip, 0, LIP_HDR_SIZE);
+       lip->lip_magic = LIP_MAGIC;
+       nob           -= LIP_HDR_SIZE;
+
+       /* compute size needed to store a key/record pair */
+       size = ii->ii_recsize + ii->ii_keysize;
+       if ((ii->ii_flags & II_FL_NOHASH) == 0)
+               /* add hash if the client wants it */
+               size += sizeof(__u64);
+
+       entry = lip->lip_entries;
+       do {
+               char            *tmp_entry = entry;
+               struct dt_key   *key;
+               __u64           hash;
+               __u16           keysize;
+               __u16           recsize;
+
+               /* fetch 64-bit hash value */
+               hash = iops->store(env, it);
+               ii->ii_hash_end = hash;
+
+               if (OBD_FAIL_CHECK(OBD_FAIL_OBD_IDX_READ_BREAK)) {
+                       if (lip->lip_nr != 0)
+                               GOTO(out, rc = 0);
+               }
+
+               if (nob < size) {
+                       if (lip->lip_nr == 0)
+                               GOTO(out, rc = -EINVAL);
+                       GOTO(out, rc = 0);
+               }
+
+               if (!(ii->ii_flags & II_FL_NOHASH)) {
+                       /* client wants to the 64-bit hash value associated with
+                        * each record */
+                       memcpy(tmp_entry, &hash, sizeof(hash));
+                       tmp_entry += sizeof(hash);
+               }
+
+               if (ii->ii_flags & II_FL_VARKEY)
+                       keysize = iops->key_size(env, it);
+               else
+                       keysize = ii->ii_keysize;
+
+               if (!(ii->ii_flags & II_FL_NOKEY)) {
+                       /* then the key value */
+                       key = iops->key(env, it);
+                       memcpy(tmp_entry, key, keysize);
+                       tmp_entry += keysize;
+               }
+
+               /* and finally the record */
+               rc = iops->rec(env, it, (struct dt_rec *)tmp_entry, attr);
+               if (rc != -ESTALE) {
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       /* hash/key/record successfully copied! */
+                       lip->lip_nr++;
+                       if (unlikely(lip->lip_nr == 1 && ii->ii_count == 0))
+                               ii->ii_hash_start = hash;
+
+                       if (ii->ii_flags & II_FL_VARREC)
+                               recsize = iops->rec_size(env, it, attr);
+                       else
+                               recsize = ii->ii_recsize;
+
+                       entry = tmp_entry + recsize;
+                       nob -= size;
+               }
+
+               /* move on to the next record */
+               do {
+                       rc = iops->next(env, it);
+               } while (rc == -ESTALE);
+
+       } while (rc == 0);
+
+       GOTO(out, rc);
+out:
+       if (rc >= 0 && lip->lip_nr > 0)
+               /* one more container */
+               ii->ii_count++;
+       if (rc > 0)
+               /* no more entries */
+               ii->ii_hash_end = II_END_OFF;
+       return rc;
+}
+
+
+/*
+ * Walk index and fill lu_page containers with key/record pairs
+ *
+ * \param env - is the environment passed by the caller
+ * \param obj - is the index object to parse
+ * \param rdpg - is the lu_rdpg descriptor associated with the transfer
+ * \param filler - is the callback function responsible for filling a lu_page
+ *                 with key/record pairs in the format wanted by the caller
+ * \param arg    - is an opaq argument passed to the filler function
+ *
+ * \retval sum (in bytes) of all filled lu_pages
+ * \retval -ve errno on failure
+ */
+int dt_index_walk(const struct lu_env *env, struct dt_object *obj,
+                 const struct lu_rdpg *rdpg, dt_index_page_build_t filler,
+                 void *arg)
+{
+       struct dt_it            *it;
+       const struct dt_it_ops  *iops;
+       size_t                   pageidx, nob, nlupgs = 0;
+       int                      rc;
+       ENTRY;
+
+       LASSERT(rdpg->rp_pages != NULL);
+       LASSERT(obj->do_index_ops != NULL);
+
+       nob = rdpg->rp_count;
+       if (nob == 0)
+               RETURN(-EFAULT);
+
+       /* Iterate through index and fill containers from @rdpg */
+       iops = &obj->do_index_ops->dio_it;
+       LASSERT(iops != NULL);
+       it = iops->init(env, obj, rdpg->rp_attrs);
+       if (IS_ERR(it))
+               RETURN(PTR_ERR(it));
+
+       rc = iops->load(env, it, rdpg->rp_hash);
+       if (rc == 0) {
+               /*
+                * Iterator didn't find record with exactly the key requested.
+                *
+                * It is currently either
+                *
+                *     - positioned above record with key less than
+                *     requested---skip it.
+                *     - or not positioned at all (is in IAM_IT_SKEWED
+                *     state)---position it on the next item.
+                */
+               rc = iops->next(env, it);
+       } else if (rc > 0) {
+               rc = 0;
+       } else {
+               if (rc == -ENODATA)
+                       rc = 0;
+               GOTO(out, rc);
+       }
+
+       /* Fill containers one after the other. There might be multiple
+        * containers per physical page.
+        *
+        * At this point and across for-loop:
+        *  rc == 0 -> ok, proceed.
+        *  rc >  0 -> end of index.
+        *  rc <  0 -> error. */
+       for (pageidx = 0; rc == 0 && nob > 0; pageidx++) {
+               union lu_page   *lp;
+               int              i;
+
+               LASSERT(pageidx < rdpg->rp_npages);
+               lp = kmap(rdpg->rp_pages[pageidx]);
+
+               /* fill lu pages */
+               for (i = 0; i < LU_PAGE_COUNT; i++, lp++, nob -= LU_PAGE_SIZE) {
+                       rc = filler(env, lp, min_t(size_t, nob, LU_PAGE_SIZE),
+                                   iops, it, rdpg->rp_attrs, arg);
+                       if (rc < 0)
+                               break;
+                       /* one more lu_page */
+                       nlupgs++;
+                       if (rc > 0)
+                               /* end of index */
+                               break;
+               }
+               kunmap(rdpg->rp_pages[i]);
+       }
+
+out:
+       iops->put(env, it);
+       iops->fini(env, it);
+
+       if (rc >= 0)
+               rc = min_t(size_t, nlupgs * LU_PAGE_SIZE, rdpg->rp_count);
+
+       RETURN(rc);
+}
+EXPORT_SYMBOL(dt_index_walk);
+
+/**
+ * Walk key/record pairs of an index and copy them into 4KB containers to be
+ * transferred over the network. This is the common handler for OBD_IDX_READ
+ * RPC processing.
+ *
+ * \param env - is the environment passed by the caller
+ * \param dev - is the dt_device storing the index
+ * \param ii  - is the idx_info structure packed by the client in the
+ *              OBD_IDX_READ request
+ * \param rdpg - is the lu_rdpg descriptor
+ *
+ * \retval on success, return sum (in bytes) of all filled containers
+ * \retval appropriate error otherwise.
+ */
+int dt_index_read(const struct lu_env *env, struct dt_device *dev,
+                 struct idx_info *ii, const struct lu_rdpg *rdpg)
+{
+       const struct dt_index_features  *feat;
+       struct dt_object                *obj;
+       int                              rc;
+       ENTRY;
+
+       /* rp_count shouldn't be null and should be a multiple of the container
+        * size */
+       if (rdpg->rp_count == 0 || (rdpg->rp_count & (LU_PAGE_SIZE - 1)) != 0)
+               RETURN(-EFAULT);
+
+       if (!fid_is_quota(&ii->ii_fid) && !fid_is_layout_rbtree(&ii->ii_fid) &&
+           !fid_is_norm(&ii->ii_fid))
+               RETURN(-EOPNOTSUPP);
+
+       /* lookup index object subject to the transfer */
+       obj = dt_locate(env, dev, &ii->ii_fid);
+       if (IS_ERR(obj))
+               RETURN(PTR_ERR(obj));
+       if (dt_object_exists(obj) == 0)
+               GOTO(out, rc = -ENOENT);
+
+       /* fetch index features associated with index object */
+       feat = dt_index_feat_select(fid_seq(&ii->ii_fid),
+                                   lu_object_attr(&obj->do_lu));
+       if (IS_ERR(feat))
+               GOTO(out, rc = PTR_ERR(feat));
+
+       /* load index feature if not done already */
+       if (obj->do_index_ops == NULL) {
+               rc = obj->do_ops->do_index_try(env, obj, feat);
+               if (rc)
+                       GOTO(out, rc);
+       }
+
+       /* fill ii_flags with supported index features */
+       ii->ii_flags &= (II_FL_NOHASH | II_FL_NOKEY | II_FL_VARKEY |
+                        II_FL_VARREC);
+
+       if (!(feat->dif_flags & DT_IND_VARKEY))
+               ii->ii_keysize = feat->dif_keysize_max;
+
+       if (!(feat->dif_flags & DT_IND_VARREC))
+               ii->ii_recsize = feat->dif_recsize_max;
+
+       if (feat->dif_flags & DT_IND_NONUNQ)
+               /* key isn't necessarily unique */
+               ii->ii_flags |= II_FL_NONUNQ;
+
+       if (!fid_is_layout_rbtree(&ii->ii_fid)) {
+               dt_read_lock(env, obj, 0);
+               /* fetch object version before walking the index */
+               ii->ii_version = dt_version_get(env, obj);
+       }
+
+       /* walk the index and fill lu_idxpages with key/record pairs */
+       rc = dt_index_walk(env, obj, rdpg, dt_index_page_build, ii);
+       if (!fid_is_layout_rbtree(&ii->ii_fid))
+               dt_read_unlock(env, obj);
+
+       if (rc == 0) {
+               /* index is empty */
+               LASSERT(ii->ii_count == 0);
+               ii->ii_hash_end = II_END_OFF;
+       }
+
+       GOTO(out, rc);
+out:
+       lu_object_put(env, &obj->do_lu);
+       return rc;
+}
+EXPORT_SYMBOL(dt_index_read);
+
+#ifdef CONFIG_PROC_FS
+int lprocfs_dt_blksize_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0)
+               seq_printf(m, "%u\n", (unsigned) osfs.os_bsize);
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_blksize_seq_show);
+
+int lprocfs_dt_kbytestotal_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0) {
+               __u32 blk_size = osfs.os_bsize >> 10;
+               __u64 result = osfs.os_blocks;
+
+               while (blk_size >>= 1)
+                       result <<= 1;
+
+               seq_printf(m, LPU64"\n", result);
+       }
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_kbytestotal_seq_show);
+
+int lprocfs_dt_kbytesfree_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0) {
+               __u32 blk_size = osfs.os_bsize >> 10;
+               __u64 result = osfs.os_bfree;
+
+               while (blk_size >>= 1)
+                       result <<= 1;
+
+               seq_printf(m, LPU64"\n", result);
+       }
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_kbytesfree_seq_show);
+
+int lprocfs_dt_kbytesavail_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0) {
+               __u32 blk_size = osfs.os_bsize >> 10;
+               __u64 result = osfs.os_bavail;
+
+               while (blk_size >>= 1)
+                       result <<= 1;
+
+               seq_printf(m, LPU64"\n", result);
+       }
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_kbytesavail_seq_show);
+
+int lprocfs_dt_filestotal_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0)
+               seq_printf(m, LPU64"\n", osfs.os_files);
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_filestotal_seq_show);
+
+int lprocfs_dt_filesfree_seq_show(struct seq_file *m, void *v)
+{
+       struct dt_device *dt = m->private;
+       struct obd_statfs osfs;
+
+       int rc = dt_statfs(NULL, dt, &osfs);
+       if (rc == 0)
+               seq_printf(m, LPU64"\n", osfs.os_ffree);
+       return rc;
+}
+EXPORT_SYMBOL(lprocfs_dt_filesfree_seq_show);
+
+#endif /* CONFIG_PROC_FS */