Whamcloud - gitweb
LU-6434 ofd: object reference leaks in ofd_preprw_write
[fs/lustre-release.git] / lustre / ofd / ofd_io.c
index 7d33fc1..177f58b 100644 (file)
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, 2013, Intel Corporation.
+ * Copyright (c) 2012, 2014 Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  *
  * lustre/ofd/ofd_io.c
  *
- * Author: Alex Tomas <bzzz@whamcloud.com>
+ * This file provides functions to handle IO requests from clients and
+ * also LFSCK routines to check parent file identifier (PFID) consistency.
+ *
+ * Author: Alexey Zhuravlev <alexey.zhuravlev@intel.com>
+ * Author: Fan Yong <fan.yong@intel.com>
  */
 
 #define DEBUG_SUBSYSTEM S_FILTER
 
 #include "ofd_internal.h"
 
+struct ofd_inconsistency_item {
+       struct list_head         oii_list;
+       struct ofd_object       *oii_obj;
+       struct lu_fid            oii_pfid;
+};
+
+/**
+ * Verify single object for parent FID consistency.
+ *
+ * Part of LFSCK processing which checks single object PFID stored in extended
+ * attribute (XATTR) against real FID of MDT parent object received by LFSCK.
+ * This verifies that the OST object is being referenced by only a single MDT
+ * object.
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ * \param[in] oii      object-related local data
+ * \param[in] lr       LFSCK request data
+ */
+static void ofd_inconsistency_verify_one(const struct lu_env *env,
+                                        struct ofd_device *ofd,
+                                        struct ofd_inconsistency_item *oii,
+                                        struct lfsck_request *lr)
+{
+       struct ofd_object       *fo     = oii->oii_obj;
+       struct lu_fid           *pfid   = &fo->ofo_pfid;
+       int                      rc;
+
+       LASSERT(fo->ofo_pfid_checking);
+       LASSERT(!fo->ofo_pfid_verified);
+
+       lr->lr_fid = fo->ofo_header.loh_fid; /* OST-object itself FID. */
+       lr->lr_fid2 = oii->oii_pfid; /* client given PFID. */
+       lr->lr_fid3 = *pfid; /* OST local stored PFID. */
+
+       rc = lfsck_in_notify(env, ofd->ofd_osd, lr, NULL);
+       ofd_write_lock(env, fo);
+       switch (lr->lr_status) {
+       case LPVS_INIT:
+               LASSERT(rc <= 0);
+
+               if (rc < 0)
+                       CDEBUG(D_LFSCK, "%s: fail to verify OST local stored "
+                              "PFID xattr for "DFID", the client given PFID "
+                              DFID", OST local stored PFID "DFID": rc = %d\n",
+                              ofd_name(ofd), PFID(&fo->ofo_header.loh_fid),
+                              PFID(&oii->oii_pfid), PFID(pfid), rc);
+               else
+                       fo->ofo_pfid_verified = 1;
+               break;
+       case LPVS_INCONSISTENT:
+               LASSERT(rc != 0);
+
+               ofd->ofd_inconsistency_self_detected++;
+               if (rc < 0)
+                       CDEBUG(D_LFSCK, "%s: fail to verify the client given "
+                              "PFID for "DFID", the client given PFID "DFID
+                              ", local stored PFID "DFID": rc = %d\n",
+                              ofd_name(ofd), PFID(&fo->ofo_header.loh_fid),
+                              PFID(&oii->oii_pfid), PFID(pfid), rc);
+               else
+                       CDEBUG(D_LFSCK, "%s: both the client given PFID and "
+                              "the OST local stored PFID are stale for the "
+                              "OST-object "DFID", client given PFID is "DFID
+                              ", local stored PFID is "DFID"\n",
+                              ofd_name(ofd), PFID(&fo->ofo_header.loh_fid),
+                              PFID(&oii->oii_pfid), PFID(pfid));
+               break;
+       case LPVS_INCONSISTENT_TOFIX:
+               ofd->ofd_inconsistency_self_detected++;
+               if (rc == 0) {
+                       ofd->ofd_inconsistency_self_repaired++;
+                       CDEBUG(D_LFSCK, "%s: fixed the staled OST PFID xattr "
+                              "for "DFID", with the client given PFID "DFID
+                              ", the old stored PFID "DFID"\n",
+                              ofd_name(ofd), PFID(&fo->ofo_header.loh_fid),
+                              PFID(&oii->oii_pfid), PFID(pfid));
+               } else if (rc < 0) {
+                       CDEBUG(D_LFSCK, "%s: fail to fix the OST PFID xattr "
+                              "for "DFID", client given PFID "DFID", local "
+                              "stored PFID "DFID": rc = %d\n",
+                              ofd_name(ofd), PFID(&fo->ofo_header.loh_fid),
+                              PFID(&oii->oii_pfid), PFID(pfid), rc);
+               }
+               *pfid = oii->oii_pfid;
+               fo->ofo_pfid_verified = 1;
+               break;
+       default:
+               break;
+       }
+       fo->ofo_pfid_checking = 0;
+       ofd_write_unlock(env, fo);
+
+       lu_object_put(env, &fo->ofo_obj.do_lu);
+       OBD_FREE_PTR(oii);
+}
+
+/**
+ * Verification thread to check parent FID consistency.
+ *
+ * Kernel thread to check consistency of parent FID for any
+ * new item added for checking by ofd_add_inconsistency_item().
+ *
+ * \param[in] args     OFD device
+ *
+ * \retval             0 on successful thread termination
+ * \retval             negative value if thread can't start
+ */
+static int ofd_inconsistency_verification_main(void *args)
+{
+       struct lu_env                  env;
+       struct ofd_device             *ofd    = args;
+       struct ptlrpc_thread          *thread = &ofd->ofd_inconsistency_thread;
+       struct ofd_inconsistency_item *oii;
+       struct lfsck_request          *lr     = NULL;
+       struct l_wait_info             lwi    = { 0 };
+       int                            rc;
+       ENTRY;
+
+       rc = lu_env_init(&env, LCT_DT_THREAD);
+       spin_lock(&ofd->ofd_inconsistency_lock);
+       thread_set_flags(thread, rc != 0 ? SVC_STOPPED : SVC_RUNNING);
+       wake_up_all(&thread->t_ctl_waitq);
+       spin_unlock(&ofd->ofd_inconsistency_lock);
+       if (rc != 0)
+               RETURN(rc);
+
+       OBD_ALLOC_PTR(lr);
+       if (unlikely(lr == NULL))
+               GOTO(out, rc = -ENOMEM);
+
+       lr->lr_event = LE_PAIRS_VERIFY;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
+
+       spin_lock(&ofd->ofd_inconsistency_lock);
+       while (1) {
+               if (unlikely(!thread_is_running(thread)))
+                       break;
+
+               while (!list_empty(&ofd->ofd_inconsistency_list)) {
+                       oii = list_entry(ofd->ofd_inconsistency_list.next,
+                                        struct ofd_inconsistency_item,
+                                        oii_list);
+                       list_del_init(&oii->oii_list);
+                       spin_unlock(&ofd->ofd_inconsistency_lock);
+                       ofd_inconsistency_verify_one(&env, ofd, oii, lr);
+                       spin_lock(&ofd->ofd_inconsistency_lock);
+               }
+
+               spin_unlock(&ofd->ofd_inconsistency_lock);
+               l_wait_event(thread->t_ctl_waitq,
+                            !list_empty(&ofd->ofd_inconsistency_list) ||
+                            !thread_is_running(thread),
+                            &lwi);
+               spin_lock(&ofd->ofd_inconsistency_lock);
+       }
+
+       while (!list_empty(&ofd->ofd_inconsistency_list)) {
+               struct ofd_object *fo;
+
+               oii = list_entry(ofd->ofd_inconsistency_list.next,
+                                struct ofd_inconsistency_item,
+                                oii_list);
+               list_del_init(&oii->oii_list);
+               fo = oii->oii_obj;
+               spin_unlock(&ofd->ofd_inconsistency_lock);
+
+               ofd_write_lock(&env, fo);
+               fo->ofo_pfid_checking = 0;
+               ofd_write_unlock(&env, fo);
+
+               lu_object_put(&env, &fo->ofo_obj.do_lu);
+               OBD_FREE_PTR(oii);
+               spin_lock(&ofd->ofd_inconsistency_lock);
+       }
+
+       OBD_FREE_PTR(lr);
+
+       GOTO(out, rc = 0);
+
+out:
+       thread_set_flags(thread, SVC_STOPPED);
+       wake_up_all(&thread->t_ctl_waitq);
+       spin_unlock(&ofd->ofd_inconsistency_lock);
+       lu_env_fini(&env);
+
+       return rc;
+}
+
+/**
+ * Start parent FID verification thread.
+ *
+ * See ofd_inconsistency_verification_main().
+ *
+ * \param[in] ofd      OFD device
+ *
+ * \retval             0 on successful start of thread
+ * \retval             negative value on error
+ */
+int ofd_start_inconsistency_verification_thread(struct ofd_device *ofd)
+{
+       struct ptlrpc_thread    *thread = &ofd->ofd_inconsistency_thread;
+       struct l_wait_info       lwi    = { 0 };
+       struct task_struct      *task;
+       int                      rc;
+
+       spin_lock(&ofd->ofd_inconsistency_lock);
+       if (unlikely(thread_is_running(thread))) {
+               spin_unlock(&ofd->ofd_inconsistency_lock);
+
+               return -EALREADY;
+       }
+
+       thread_set_flags(thread, 0);
+       spin_unlock(&ofd->ofd_inconsistency_lock);
+       task = kthread_run(ofd_inconsistency_verification_main, ofd,
+                          "inconsistency_verification");
+       if (IS_ERR(task)) {
+               rc = PTR_ERR(task);
+               CERROR("%s: cannot start self_repair thread: rc = %d\n",
+                      ofd_name(ofd), rc);
+       } else {
+               rc = 0;
+               l_wait_event(thread->t_ctl_waitq,
+                            thread_is_running(thread) ||
+                            thread_is_stopped(thread),
+                            &lwi);
+       }
+
+       return rc;
+}
+
+/**
+ * Stop parent FID verification thread.
+ *
+ * \param[in] ofd      OFD device
+ *
+ * \retval             0 on successful start of thread
+ * \retval             -EALREADY if thread is already stopped
+ */
+int ofd_stop_inconsistency_verification_thread(struct ofd_device *ofd)
+{
+       struct ptlrpc_thread    *thread = &ofd->ofd_inconsistency_thread;
+       struct l_wait_info       lwi    = { 0 };
+
+       spin_lock(&ofd->ofd_inconsistency_lock);
+       if (thread_is_init(thread) || thread_is_stopped(thread)) {
+               spin_unlock(&ofd->ofd_inconsistency_lock);
+
+               return -EALREADY;
+       }
+
+       thread_set_flags(thread, SVC_STOPPING);
+       spin_unlock(&ofd->ofd_inconsistency_lock);
+       wake_up_all(&thread->t_ctl_waitq);
+       l_wait_event(thread->t_ctl_waitq,
+                    thread_is_stopped(thread),
+                    &lwi);
+
+       return 0;
+}
+
+/**
+ * Add new item for parent FID verification.
+ *
+ * Prepare new verification item and pass it to the dedicated
+ * verification thread for further processing.
+ *
+ * \param[in] env      execution environment
+ * \param[in] fo       OFD object
+ * \param[in] oa       OBDO structure with PFID
+ */
+static void ofd_add_inconsistency_item(const struct lu_env *env,
+                                      struct ofd_object *fo, struct obdo *oa)
+{
+       struct ofd_device               *ofd    = ofd_obj2dev(fo);
+       struct ofd_inconsistency_item   *oii;
+       bool                             wakeup = false;
+
+       OBD_ALLOC_PTR(oii);
+       if (oii == NULL)
+               return;
+
+       INIT_LIST_HEAD(&oii->oii_list);
+       lu_object_get(&fo->ofo_obj.do_lu);
+       oii->oii_obj = fo;
+       oii->oii_pfid.f_seq = oa->o_parent_seq;
+       oii->oii_pfid.f_oid = oa->o_parent_oid;
+       oii->oii_pfid.f_stripe_idx = oa->o_stripe_idx;
+
+       spin_lock(&ofd->ofd_inconsistency_lock);
+       if (fo->ofo_pfid_checking || fo->ofo_pfid_verified) {
+               spin_unlock(&ofd->ofd_inconsistency_lock);
+               OBD_FREE_PTR(oii);
+
+               return;
+       }
+
+       fo->ofo_pfid_checking = 1;
+       if (list_empty(&ofd->ofd_inconsistency_list))
+               wakeup = true;
+       list_add_tail(&oii->oii_list, &ofd->ofd_inconsistency_list);
+       spin_unlock(&ofd->ofd_inconsistency_lock);
+       if (wakeup)
+               wake_up_all(&ofd->ofd_inconsistency_thread.t_ctl_waitq);
+
+       /* XXX: When the found inconsistency exceeds some threshold,
+        *      we can trigger the LFSCK to scan part of the system
+        *      or the whole system, which depends on how to define
+        *      the threshold, a simple way maybe like that: define
+        *      the absolute value of how many inconsisteny allowed
+        *      to be repaired via self detect/repair mechanism, if
+        *      exceeded, then trigger the LFSCK to scan the layout
+        *      inconsistency within the whole system. */
+}
+
+/**
+ * Verify parent FID of an object.
+ *
+ * Check the parent FID is sane and start extended
+ * verification procedure otherwise.
+ *
+ * \param[in] env      execution environment
+ * \param[in] fo       OFD object
+ * \param[in] oa       OBDO structure with PFID
+ *
+ * \retval             0 on successful verification
+ * \retval             -EINPROGRESS if PFID is being repaired
+ * \retval             -EPERM if PFID was verified but still insane
+ */
+int ofd_verify_ff(const struct lu_env *env, struct ofd_object *fo,
+                 struct obdo *oa)
+{
+       struct lu_fid   *pfid   = &fo->ofo_pfid;
+       int              rc     = 0;
+       ENTRY;
+
+       if (fid_is_sane(pfid)) {
+               if (likely(oa->o_parent_seq == pfid->f_seq &&
+                          oa->o_parent_oid == pfid->f_oid &&
+                          oa->o_stripe_idx == pfid->f_stripe_idx))
+                       RETURN(0);
+
+               if (fo->ofo_pfid_verified)
+                       RETURN(-EPERM);
+       }
+
+       /* The OST-object may be inconsistent, and we need further verification.
+        * To avoid block the RPC service thread, return -EINPROGRESS to client
+        * and make it retry later. */
+       if (fo->ofo_pfid_checking)
+               RETURN(-EINPROGRESS);
+
+       rc = ofd_object_ff_load(env, fo);
+       if (rc == -ENODATA)
+               RETURN(0);
+
+       if (rc < 0)
+               RETURN(rc);
+
+       if (likely(oa->o_parent_seq == pfid->f_seq &&
+                  oa->o_parent_oid == pfid->f_oid &&
+                  oa->o_stripe_idx == pfid->f_stripe_idx))
+               RETURN(0);
+
+       /* Push it to the dedicated thread for further verification. */
+       ofd_add_inconsistency_item(env, fo, oa);
+
+       RETURN(-EINPROGRESS);
+}
+
+/**
+ * Prepare buffers for read request processing.
+ *
+ * This function converts remote buffers from client to local buffers
+ * and prepares the latter.
+ *
+ * \param[in] env      execution environment
+ * \param[in] exp      OBD export of client
+ * \param[in] ofd      OFD device
+ * \param[in] fid      FID of object
+ * \param[in] la       object attributes
+ * \param[in] oa       OBDO structure from client
+ * \param[in] niocount number of remote buffers
+ * \param[in] rnb      remote buffers
+ * \param[in] nr_local number of local buffers
+ * \param[in] lnb      local buffers
+ * \param[in] jobid    job ID name
+ *
+ * \retval             0 on successful prepare
+ * \retval             negative value on error
+ */
 static int ofd_preprw_read(const struct lu_env *env, struct obd_export *exp,
                           struct ofd_device *ofd, const struct lu_fid *fid,
-                          struct lu_attr *la, int niocount,
+                          struct lu_attr *la, struct obdo *oa, int niocount,
                           struct niobuf_remote *rnb, int *nr_local,
                           struct niobuf_local *lnb, char *jobid)
 {
@@ -63,11 +455,16 @@ static int ofd_preprw_read(const struct lu_env *env, struct obd_export *exp,
        if (!ofd_object_exists(fo))
                GOTO(unlock, rc = -ENOENT);
 
-       /* parse remote buffers to local buffers and prepare the latter */
+       if (ofd->ofd_lfsck_verify_pfid && oa->o_valid & OBD_MD_FLFID) {
+               rc = ofd_verify_ff(env, fo, oa);
+               if (rc != 0)
+                       GOTO(unlock, rc);
+       }
+
        *nr_local = 0;
        for (i = 0, j = 0; i < niocount; i++) {
                rc = dt_bufs_get(env, ofd_object_child(fo), rnb + i,
-                                lnb + j, 0, ofd_object_capa(env, fo));
+                                lnb + j, 0);
                if (unlikely(rc < 0))
                        GOTO(buf_put, rc);
                LASSERT(rc <= PTLRPC_MAX_BRW_PAGES);
@@ -79,8 +476,7 @@ static int ofd_preprw_read(const struct lu_env *env, struct obd_export *exp,
        }
 
        LASSERT(*nr_local > 0 && *nr_local <= PTLRPC_MAX_BRW_PAGES);
-       rc = dt_attr_get(env, ofd_object_child(fo), la,
-                        ofd_object_capa(env, fo));
+       rc = dt_attr_get(env, ofd_object_child(fo), la);
        if (unlikely(rc))
                GOTO(buf_put, rc);
 
@@ -99,6 +495,29 @@ unlock:
        return rc;
 }
 
+/**
+ * Prepare buffers for write request processing.
+ *
+ * This function converts remote buffers from client to local buffers
+ * and prepares the latter. If there is recovery in progress and required
+ * object is missing then it can be re-created before write.
+ *
+ * \param[in] env      execution environment
+ * \param[in] exp      OBD export of client
+ * \param[in] ofd      OFD device
+ * \param[in] fid      FID of object
+ * \param[in] la       object attributes
+ * \param[in] oa       OBDO structure from client
+ * \param[in] objcount always 1
+ * \param[in] obj      object data
+ * \param[in] rnb      remote buffers
+ * \param[in] nr_local number of local buffers
+ * \param[in] lnb      local buffers
+ * \param[in] jobid    job ID name
+ *
+ * \retval             0 on successful prepare
+ * \retval             negative value on error
+ */
 static int ofd_preprw_write(const struct lu_env *env, struct obd_export *exp,
                            struct ofd_device *ofd, const struct lu_fid *fid,
                            struct lu_attr *la, struct obdo *oa,
@@ -114,27 +533,62 @@ static int ofd_preprw_write(const struct lu_env *env, struct obd_export *exp,
        LASSERT(objcount == 1);
 
        if (unlikely(exp->exp_obd->obd_recovering)) {
-               struct ofd_thread_info *info = ofd_info(env);
-
-               /* copied from ofd_precreate_object */
-               /* XXX this should be consolidated to use the same code
-                *     instead of a copy, due to the ongoing risk of bugs. */
-               memset(&info->fti_attr, 0, sizeof(info->fti_attr));
-               info->fti_attr.la_valid = LA_TYPE | LA_MODE;
-               info->fti_attr.la_mode = S_IFREG | S_ISUID | S_ISGID | 0666;
-               info->fti_attr.la_valid |= LA_ATIME | LA_MTIME | LA_CTIME;
-               /* Initialize a/c/m time so any client timestamp will always
-                * be newer and update the inode. ctime = 0 is also handled
-                * specially in osd_inode_setattr().  See LU-221, LU-1042 */
-               info->fti_attr.la_atime = 0;
-               info->fti_attr.la_mtime = 0;
-               info->fti_attr.la_ctime = 0;
-
-               fo = ofd_object_find_or_create(env, ofd, fid, &info->fti_attr);
-       } else {
-               fo = ofd_object_find(env, ofd, fid);
+               u64 seq = fid_seq(fid);
+               u64 oid = fid_oid(fid);
+               struct ofd_seq *oseq;
+
+               oseq = ofd_seq_load(env, ofd, seq);
+               if (IS_ERR(oseq)) {
+                       CERROR("%s: Can't find FID Sequence "LPX64": rc = %d\n",
+                              ofd_name(ofd), seq, (int)PTR_ERR(oseq));
+                       GOTO(out, rc = -EINVAL);
+               }
+
+               if (oid > ofd_seq_last_oid(oseq)) {
+                       int sync = 0;
+                       int diff;
+
+                       mutex_lock(&oseq->os_create_lock);
+                       diff = oid - ofd_seq_last_oid(oseq);
+
+                       /* Do sync create if the seq is about to used up */
+                       if (fid_seq_is_idif(seq) || fid_seq_is_mdt0(seq)) {
+                               if (unlikely(oid >= IDIF_MAX_OID - 1))
+                                       sync = 1;
+                       } else if (fid_seq_is_norm(seq)) {
+                               if (unlikely(oid >=
+                                            LUSTRE_DATA_SEQ_MAX_WIDTH - 1))
+                                       sync = 1;
+                       } else {
+                               CERROR("%s : invalid o_seq "DOSTID"\n",
+                                      ofd_name(ofd), POSTID(&oa->o_oi));
+                               mutex_unlock(&oseq->os_create_lock);
+                               ofd_seq_put(env, oseq);
+                               GOTO(out, rc = -EINVAL);
+                       }
+
+                       while (diff > 0) {
+                               u64 next_id = ofd_seq_last_oid(oseq) + 1;
+                               int count = ofd_precreate_batch(ofd, diff);
+
+                               rc = ofd_precreate_objects(env, ofd, next_id,
+                                                          oseq, count, sync);
+                               if (rc < 0) {
+                                       mutex_unlock(&oseq->os_create_lock);
+                                       ofd_seq_put(env, oseq);
+                                       GOTO(out, rc);
+                               }
+
+                               diff -= rc;
+                       }
+
+                       mutex_unlock(&oseq->os_create_lock);
+               }
+
+               ofd_seq_put(env, oseq);
        }
 
+       fo = ofd_object_find(env, ofd, fid);
        if (IS_ERR(fo))
                GOTO(out, rc = PTR_ERR(fo));
        LASSERT(fo != NULL);
@@ -148,6 +602,15 @@ static int ofd_preprw_write(const struct lu_env *env, struct obd_export *exp,
                GOTO(out, rc = -ENOENT);
        }
 
+       if (ofd->ofd_lfsck_verify_pfid && oa->o_valid & OBD_MD_FLFID) {
+               rc = ofd_verify_ff(env, fo, oa);
+               if (rc != 0) {
+                       ofd_read_unlock(env, fo);
+                       ofd_object_put(env, fo);
+                       GOTO(out, rc);
+               }
+       }
+
        /* Process incoming grant info, set OBD_BRW_GRANTED flag and grant some
         * space back if possible */
        ofd_grant_prepare_write(env, exp, oa, rnb, obj->ioo_bufcnt);
@@ -156,8 +619,7 @@ static int ofd_preprw_write(const struct lu_env *env, struct obd_export *exp,
        *nr_local = 0;
        for (i = 0, j = 0; i < obj->ioo_bufcnt; i++) {
                rc = dt_bufs_get(env, ofd_object_child(fo),
-                                rnb + i, lnb + j, 1,
-                                ofd_object_capa(env, fo));
+                                rnb + i, lnb + j, 1);
                if (unlikely(rc < 0))
                        GOTO(err, rc);
                LASSERT(rc <= PTLRPC_MAX_BRW_PAGES);
@@ -187,6 +649,7 @@ static int ofd_preprw_write(const struct lu_env *env, struct obd_export *exp,
 err:
        dt_bufs_put(env, ofd_object_child(fo), lnb, *nr_local);
        ofd_read_unlock(env, fo);
+       ofd_object_put(env, fo);
        /* ofd_grant_prepare_write() was called, so we must commit */
        ofd_grant_commit(env, exp, rc);
 out:
@@ -197,11 +660,30 @@ out:
        return rc;
 }
 
+/**
+ * Prepare bulk IO requests for processing.
+ *
+ * This function does initial checks of IO and calls corresponding
+ * functions for read/write processing.
+ *
+ * \param[in] env      execution environment
+ * \param[in] cmd      IO type (read/write)
+ * \param[in] exp      OBD export of client
+ * \param[in] oa       OBDO structure from request
+ * \param[in] objcount always 1
+ * \param[in] obj      object data
+ * \param[in] rnb      remote buffers
+ * \param[in] nr_local number of local buffers
+ * \param[in] lnb      local buffers
+ * \param[in] oti      request data from OST
+ *
+ * \retval             0 on successful prepare
+ * \retval             negative value on error
+ */
 int ofd_preprw(const struct lu_env *env, int cmd, struct obd_export *exp,
               struct obdo *oa, int objcount, struct obd_ioobj *obj,
               struct niobuf_remote *rnb, int *nr_local,
-              struct niobuf_local *lnb, struct obd_trans_info *oti,
-              struct lustre_capa *capa)
+              struct niobuf_local *lnb, struct obd_trans_info *oti)
 {
        struct tgt_session_info *tsi = tgt_ses_info(env);
        struct ofd_device       *ofd = ofd_exp(exp);
@@ -221,7 +703,7 @@ int ofd_preprw(const struct lu_env *env, int cmd, struct obd_export *exp,
                LASSERT(oti != NULL);
                info = ofd_info_init(env, exp);
                ofd_oti2info(info, oti);
-               jobid = oti->oti_jobid;
+               jobid = NULL;
        } else {
                info = tsi2ofd_info(tsi);
                jobid = tsi->tsi_jobid;
@@ -254,24 +736,15 @@ int ofd_preprw(const struct lu_env *env, int cmd, struct obd_export *exp,
        LASSERT(obj->ioo_bufcnt > 0);
 
        if (cmd == OBD_BRW_WRITE) {
-               rc = ofd_auth_capa(exp, fid, ostid_seq(&oa->o_oi),
-                                  capa, CAPA_OPC_OSS_WRITE);
-               if (rc == 0) {
-                       la_from_obdo(&info->fti_attr, oa, OBD_MD_FLGETATTR);
-                       rc = ofd_preprw_write(env, exp, ofd, fid,
-                                             &info->fti_attr, oa, objcount,
-                                             obj, rnb, nr_local, lnb, jobid);
-               }
+               la_from_obdo(&info->fti_attr, oa, OBD_MD_FLGETATTR);
+               rc = ofd_preprw_write(env, exp, ofd, fid, &info->fti_attr, oa,
+                                     objcount, obj, rnb, nr_local, lnb, jobid);
        } else if (cmd == OBD_BRW_READ) {
-               rc = ofd_auth_capa(exp, fid, ostid_seq(&oa->o_oi),
-                                  capa, CAPA_OPC_OSS_READ);
-               if (rc == 0) {
-                       ofd_grant_prepare_read(env, exp, oa);
-                       rc = ofd_preprw_read(env, exp, ofd, fid,
-                                            &info->fti_attr, obj->ioo_bufcnt,
-                                            rnb, nr_local, lnb, jobid);
-                       obdo_from_la(oa, &info->fti_attr, LA_ATIME);
-               }
+               ofd_grant_prepare_read(env, exp, oa);
+               rc = ofd_preprw_read(env, exp, ofd, fid, &info->fti_attr, oa,
+                                    obj->ioo_bufcnt, rnb, nr_local, lnb,
+                                    jobid);
+               obdo_from_la(oa, &info->fti_attr, LA_ATIME);
        } else {
                CERROR("%s: wrong cmd %d received!\n",
                       exp->exp_obd->obd_name, cmd);
@@ -280,6 +753,21 @@ int ofd_preprw(const struct lu_env *env, int cmd, struct obd_export *exp,
        RETURN(rc);
 }
 
+/**
+ * Drop reference on local buffers for read bulk IO.
+ *
+ * This will free all local buffers use by this read request.
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ * \param[in] fid      object FID
+ * \param[in] objcount always 1
+ * \param[in] niocount number of local buffers
+ * \param[in] lnb      local buffers
+ *
+ * \retval             0 on successful execution
+ * \retval             negative value on error
+ */
 static int
 ofd_commitrw_read(const struct lu_env *env, struct ofd_device *ofd,
                  const struct lu_fid *fid, int objcount, int niocount,
@@ -306,6 +794,21 @@ ofd_commitrw_read(const struct lu_env *env, struct ofd_device *ofd,
        RETURN(0);
 }
 
+/**
+ * Set attributes of object during write bulk IO processing.
+ *
+ * Change object attributes and write parent FID into extended
+ * attributes when needed.
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ * \param[in] ofd_obj  OFD object
+ * \param[in] la       object attributes
+ * \param[in] ff       parent FID
+ *
+ * \retval             0 on successful attributes update
+ * \retval             negative value on error
+ */
 static int
 ofd_write_attr_set(const struct lu_env *env, struct ofd_device *ofd,
                   struct ofd_object *ofd_obj, struct lu_attr *la,
@@ -332,7 +835,7 @@ ofd_write_attr_set(const struct lu_env *env, struct ofd_device *ofd,
                GOTO(out, rc);
 
        if (ff != NULL) {
-               rc = ofd_object_ff_check(env, ofd_obj);
+               rc = ofd_object_ff_load(env, ofd_obj);
                if (rc == -ENODATA)
                        ff_needed = 1;
                else if (rc < 0)
@@ -376,8 +879,7 @@ ofd_write_attr_set(const struct lu_env *env, struct ofd_device *ofd,
 
        /* set uid/gid */
        if (la->la_valid) {
-               rc = dt_attr_set(env, dt_obj, la, th,
-                                ofd_object_capa(env, ofd_obj));
+               rc = dt_attr_set(env, dt_obj, la, th);
                if (rc)
                        GOTO(out_tx, rc);
        }
@@ -388,12 +890,21 @@ ofd_write_attr_set(const struct lu_env *env, struct ofd_device *ofd,
                        GOTO(out_tx, rc);
 
                rc = dt_xattr_set(env, dt_obj, &info->fti_buf, XATTR_NAME_FID,
-                                 0, th, BYPASS_CAPA);
-               if (rc)
-                       GOTO(out_tx, rc);
+                                 0, th);
+               if (rc == 0) {
+                       ofd_obj->ofo_pfid.f_seq = le64_to_cpu(ff->ff_parent.f_seq);
+                       ofd_obj->ofo_pfid.f_oid = le32_to_cpu(ff->ff_parent.f_oid);
+                       /* Currently, the filter_fid::ff_parent::f_ver is not
+                        * the real parent MDT-object's FID::f_ver, instead it
+                        * is the OST-object index in its parent MDT-object's
+                        * layout EA. */
+                       ofd_obj->ofo_pfid.f_stripe_idx =
+                                       le32_to_cpu(ff->ff_parent.f_stripe_idx);
+               }
        }
 
-       EXIT;
+       GOTO(out_tx, rc);
+
 out_tx:
        dt_trans_stop(env, ofd->ofd_osd, th);
 out:
@@ -406,6 +917,17 @@ struct ofd_soft_sync_callback {
        struct obd_export       *ossc_exp;
 };
 
+/**
+ * Callback function for "soft sync" update.
+ *
+ * Reset fed_soft_sync_count upon committing the "soft_sync" update.
+ * See ofd_soft_sync_cb_add() below for more details on soft sync.
+ *
+ * \param[in] env      execution environment
+ * \param[in] th       transaction handle
+ * \param[in] cb       callback data
+ * \param[in] err      error code
+ */
 static void ofd_cb_soft_sync(struct lu_env *env, struct thandle *th,
                             struct dt_txn_commit_cb *cb, int err)
 {
@@ -420,6 +942,22 @@ static void ofd_cb_soft_sync(struct lu_env *env, struct thandle *th,
        OBD_FREE_PTR(ossc);
 }
 
+/**
+ * Add callback for "soft sync" processing.
+ *
+ * The "soft sync" mechanism does asynchronous commit when OBD_BRW_SOFT_SYNC
+ * flag is set in client buffers. The intention is for this operation to
+ * commit pages belonging to a client which has "too many" outstanding
+ * unstable pages in its cache. See LU-2139 for details.
+ *
+ * This function adds callback to be called when commit is done.
+ *
+ * \param[in] th       transaction handle
+ * \param[in] exp      OBD export of client
+ *
+ * \retval             0 on successful callback adding
+ * \retval             negative value on error
+ */
 static int ofd_soft_sync_cb_add(struct thandle *th, struct obd_export *exp)
 {
        struct ofd_soft_sync_callback           *ossc;
@@ -434,9 +972,8 @@ static int ofd_soft_sync_cb_add(struct thandle *th, struct obd_export *exp)
 
        dcb = &ossc->ossc_cb;
        dcb->dcb_func = ofd_cb_soft_sync;
-       CFS_INIT_LIST_HEAD(&dcb->dcb_linkage);
-       strncpy(dcb->dcb_name, "ofd_cb_soft_sync", MAX_COMMIT_CB_STR_LEN);
-       dcb->dcb_name[MAX_COMMIT_CB_STR_LEN - 1] = '\0';
+       INIT_LIST_HEAD(&dcb->dcb_linkage);
+       strlcpy(dcb->dcb_name, "ofd_cb_soft_sync", sizeof(dcb->dcb_name));
 
        rc = dt_trans_cb_add(th, dcb);
        if (rc) {
@@ -447,6 +984,26 @@ static int ofd_soft_sync_cb_add(struct thandle *th, struct obd_export *exp)
        return rc;
 }
 
+/**
+ * Commit bulk IO buffers to the storage.
+ *
+ * This function finalizes write IO processing by writing data to the disk.
+ * That write can be synchronous or asynchronous depending on buffers flags.
+ *
+ * \param[in] env      execution environment
+ * \param[in] exp      OBD export of client
+ * \param[in] ofd      OFD device
+ * \param[in] fid      FID of object
+ * \param[in] la       object attributes
+ * \param[in] ff       parent FID of object
+ * \param[in] objcount always 1
+ * \param[in] niocount number of local buffers
+ * \param[in] lnb      local buffers
+ * \param[in] old_rc   result of processing at this point
+ *
+ * \retval             0 on successful commit
+ * \retval             negative value on error
+ */
 static int
 ofd_commitrw_write(const struct lu_env *env, struct obd_export *exp,
                   struct ofd_device *ofd, const struct lu_fid *fid,
@@ -530,13 +1087,13 @@ retry:
                GOTO(out_stop, rc);
 
        if (la->la_valid) {
-               rc = dt_attr_set(env, o, la, th, ofd_object_capa(env, fo));
+               rc = dt_attr_set(env, o, la, th);
                if (rc)
                        GOTO(out_stop, rc);
        }
 
        /* get attr to return */
-       rc = dt_attr_get(env, o, la, ofd_object_capa(env, fo));
+       rc = dt_attr_get(env, o, la);
 
 out_stop:
        /* Force commit to make the just-deleted blocks
@@ -574,6 +1131,29 @@ out:
        RETURN(rc);
 }
 
+/**
+ * Commit bulk IO to the storage.
+ *
+ * This is companion function to the ofd_preprw(). It finishes bulk IO
+ * request processing by committing buffers to the storage (WRITE) and/or
+ * freeing those buffers (read/write). See ofd_commitrw_read() and
+ * ofd_commitrw_write() for details about each type of IO.
+ *
+ * \param[in] env      execution environment
+ * \param[in] cmd      IO type (READ/WRITE)
+ * \param[in] exp      OBD export of client
+ * \param[in] oa       OBDO structure from client
+ * \param[in] objcount always 1
+ * \param[in] obj      object data
+ * \param[in] rnb      remote buffers
+ * \param[in] npages   number of local buffers
+ * \param[in] lnb      local buffers
+ * \param[in] oti      request data from OST
+ * \param[in] old_rc   result of processing at this point
+ *
+ * \retval             0 on successful commit
+ * \retval             negative value on error
+ */
 int ofd_commitrw(const struct lu_env *env, int cmd, struct obd_export *exp,
                 struct obdo *oa, int objcount, struct obd_ioobj *obj,
                 struct niobuf_remote *rnb, int npages,
@@ -652,8 +1232,8 @@ int ofd_commitrw(const struct lu_env *env, int cmd, struct obd_export *exp,
                        ost_fid_build_resid(fid, &info->fti_resid);
                        rs = ldlm_resource_get(ns, NULL, &info->fti_resid,
                                               LDLM_EXTENT, 0);
-                       if (rs != NULL) {
-                               ns->ns_lvbo->lvbo_update(rs, NULL, 1);
+                       if (!IS_ERR(rs)) {
+                               ldlm_res_lvbo_update(rs, NULL, 1);
                                ldlm_resource_putref(rs);
                        }
                }