cluster/ec: Added erasure code translator

Change-Id: I293917501d5c2ca4cdc6303df30cf0b568cea361
BUG: 1118629
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/7749
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 1764 insertions, 0 deletions

diff --git a/xlators/cluster/ec/src/ec-inode-read.c b/xlators/cluster/ec/src/ec-inode-read.c
new file mode 100644
index 00000000000..b1db9c9fbb7
--- /dev/null
+++ b/xlators/cluster/ec/src/ec-inode-read.c
@@ -0,0 +1,1764 @@
+
+/*
+  Copyright (c) 2012 DataLab, s.l. <http://www.datalab.es>
+
+  This file is part of the cluster/ec translator for GlusterFS.
+
+  The cluster/ec translator for GlusterFS is free software: you can
+  redistribute it and/or modify it under the terms of the GNU General
+  Public License as published by the Free Software Foundation, either
+  version 3 of the License, or (at your option) any later version.
+
+  The cluster/ec translator for GlusterFS is distributed in the hope
+  that it will be useful, but WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+  PURPOSE. See the GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with the cluster/ec translator for GlusterFS. If not, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#include "xlator.h"
+#include "defaults.h"
+
+#include "ec-helpers.h"
+#include "ec-common.h"
+#include "ec-combine.h"
+#include "ec-method.h"
+#include "ec-fops.h"
+
+/* FOP: access */
+
+int32_t ec_access_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                      int32_t op_ret, int32_t op_errno, dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    if (!ec_dispatch_one_retry(fop, idx, op_ret, op_errno))
+    {
+        if (fop->cbks.access != NULL)
+        {
+            fop->cbks.access(fop->req_frame, fop, this, op_ret, op_errno,
+                             xdata);
+        }
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_access(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_access_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->access,
+                      &fop->loc[0], fop->int32, fop->xdata);
+}
+
+int32_t ec_manager_access(ec_fop_data_t * fop, int32_t state)
+{
+    switch (state)
+    {
+        case EC_STATE_INIT:
+        case EC_STATE_DISPATCH:
+            ec_dispatch_one(fop);
+
+            return EC_STATE_PREPARE_ANSWER;
+
+        case -EC_STATE_REPORT:
+            if (fop->cbks.access != NULL)
+            {
+                fop->cbks.access(fop->req_frame, fop, fop->xl, -1, fop->error,
+                                 NULL);
+            }
+
+        case EC_STATE_REPORT:
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_access(call_frame_t * frame, xlator_t * this, uintptr_t target,
+               int32_t minimum, fop_access_cbk_t func, void * data,
+               loc_t * loc, int32_t mask, dict_t * xdata)
+{
+    ec_cbk_t callback = { .access = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(ACCESS) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_ACCESS, 0, target, minimum,
+                               ec_wind_access, ec_manager_access, callback,
+                               data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    fop->int32 = mask;
+
+    if (loc != NULL)
+    {
+        if (loc_copy(&fop->loc[0], loc) != 0)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to copy a location.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL);
+    }
+}
+
+/* FOP: getxattr */
+
+int32_t ec_combine_getxattr(ec_fop_data_t * fop, ec_cbk_data_t * dst,
+                            ec_cbk_data_t * src)
+{
+    if (!ec_dict_compare(dst->dict, src->dict))
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching dictionary in "
+                                             "answers of 'GF_FOP_GETXATTR'");
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int32_t ec_getxattr_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                        int32_t op_ret, int32_t op_errno, dict_t * dict,
+                        dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_GETXATTR, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            if (dict != NULL)
+            {
+                cbk->dict = dict_ref(dict);
+                if (cbk->dict == NULL)
+                {
+                    gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                     "dictionary.");
+
+                    goto out;
+                }
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        ec_combine(cbk, ec_combine_getxattr);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_getxattr(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_getxattr_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->getxattr,
+                      &fop->loc[0], fop->str[0], fop->xdata);
+}
+
+int32_t ec_manager_getxattr(ec_fop_data_t * fop, int32_t state)
+{
+    ec_cbk_data_t * cbk;
+
+    switch (state)
+    {
+        case EC_STATE_INIT:
+        case EC_STATE_LOCK:
+            ec_lock_inode(fop, &fop->loc[0]);
+
+            return EC_STATE_DISPATCH;
+
+        case EC_STATE_DISPATCH:
+            ec_dispatch_all(fop);
+
+            return EC_STATE_PREPARE_ANSWER;
+
+        case EC_STATE_PREPARE_ANSWER:
+            cbk = fop->answer;
+            if (cbk != NULL)
+            {
+                if (!ec_dict_combine(cbk, EC_COMBINE_XDATA) ||
+                    ((cbk->op_ret >= 0) && !ec_dict_combine(cbk,
+                                                            EC_COMBINE_DICT)))
+                {
+                    if (cbk->op_ret >= 0)
+                    {
+                        cbk->op_ret = -1;
+                        cbk->op_errno = EIO;
+                    }
+                }
+                if (cbk->op_ret < 0)
+                {
+                    ec_fop_set_error(fop, cbk->op_errno);
+                }
+                else
+                {
+                    if (cbk->xdata != NULL)
+                    {
+                        dict_del(cbk->xdata, EC_XATTR_SIZE);
+                        dict_del(cbk->xdata, EC_XATTR_VERSION);
+                    }
+                    if (cbk->dict != NULL)
+                    {
+                        dict_del(cbk->dict, EC_XATTR_SIZE);
+                        dict_del(cbk->dict, EC_XATTR_VERSION);
+                    }
+                }
+            }
+            else
+            {
+                ec_fop_set_error(fop, EIO);
+            }
+
+            return EC_STATE_REPORT;
+
+        case EC_STATE_REPORT:
+            cbk = fop->answer;
+
+            GF_ASSERT(cbk != NULL);
+
+            if (fop->cbks.getxattr != NULL)
+            {
+                fop->cbks.getxattr(fop->req_frame, fop, fop->xl, cbk->op_ret,
+                                   cbk->op_errno, cbk->dict, cbk->xdata);
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_LOCK:
+        case -EC_STATE_DISPATCH:
+        case -EC_STATE_PREPARE_ANSWER:
+        case -EC_STATE_REPORT:
+            GF_ASSERT(fop->error != 0);
+
+            if (fop->cbks.getxattr != NULL)
+            {
+                fop->cbks.getxattr(fop->req_frame, fop, fop->xl, -1,
+                                   fop->error, NULL, NULL);
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_UNLOCK:
+        case EC_STATE_UNLOCK:
+            ec_unlock(fop);
+
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_getxattr(call_frame_t * frame, xlator_t * this, uintptr_t target,
+                 int32_t minimum, fop_getxattr_cbk_t func, void * data,
+                 loc_t * loc, const char * name, dict_t * xdata)
+{
+    ec_cbk_t callback = { .getxattr = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(GETXATTR) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_GETXATTR,
+                               EC_FLAG_UPDATE_LOC_INODE, target, minimum,
+                               ec_wind_getxattr, ec_manager_getxattr, callback,
+                               data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    if (loc != NULL)
+    {
+        if (loc_copy(&fop->loc[0], loc) != 0)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to copy a location.");
+
+            goto out;
+        }
+    }
+    if (name != NULL)
+    {
+        fop->str[0] = gf_strdup(name);
+        if (fop->str[0] == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to duplicate a string.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL);
+    }
+}
+
+/* FOP: fgetxattr */
+
+int32_t ec_fgetxattr_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                         int32_t op_ret, int32_t op_errno, dict_t * dict,
+                         dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_FGETXATTR, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            if (dict != NULL)
+            {
+                cbk->dict = dict_ref(dict);
+                if (cbk->dict == NULL)
+                {
+                    gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                     "dictionary.");
+
+                    goto out;
+                }
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        ec_combine(cbk, ec_combine_getxattr);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_fgetxattr(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_fgetxattr_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->fgetxattr,
+                      fop->fd, fop->str[0], fop->xdata);
+}
+
+void ec_fgetxattr(call_frame_t * frame, xlator_t * this, uintptr_t target,
+                  int32_t minimum, fop_fgetxattr_cbk_t func, void * data,
+                  fd_t * fd, const char * name, dict_t * xdata)
+{
+    ec_cbk_t callback = { .fgetxattr = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(FGETXATTR) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_FGETXATTR,
+                               EC_FLAG_UPDATE_FD_INODE, target, minimum,
+                               ec_wind_fgetxattr, ec_manager_getxattr,
+                               callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    if (fd != NULL)
+    {
+        fop->fd = fd_ref(fd);
+        if (fop->fd == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "file descriptor.");
+
+            goto out;
+        }
+    }
+    if (name != NULL)
+    {
+        fop->str[0] = gf_strdup(name);
+        if (fop->str[0] == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to duplicate a string.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL);
+    }
+}
+
+/* FOP: open */
+
+int32_t ec_combine_open(ec_fop_data_t * fop, ec_cbk_data_t * dst,
+                        ec_cbk_data_t * src)
+{
+    if (dst->fd != src->fd)
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching fd in answers "
+                                             "of 'GF_FOP_OPEN': %p <-> %p",
+               dst->fd, src->fd);
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int32_t ec_open_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                    int32_t op_ret, int32_t op_errno, fd_t * fd,
+                    dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_OPEN, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            if (fd != NULL)
+            {
+                cbk->fd = fd_ref(fd);
+                if (cbk->fd == NULL)
+                {
+                    gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                     "file descriptor.");
+
+                    goto out;
+                }
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        ec_combine(cbk, ec_combine_open);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_open(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_open_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->open,
+                      &fop->loc[0], fop->int32, fop->fd, fop->xdata);
+}
+
+int32_t ec_manager_open(ec_fop_data_t * fop, int32_t state)
+{
+    ec_cbk_data_t * cbk;
+    ec_fd_t * ctx;
+
+    switch (state)
+    {
+        case EC_STATE_INIT:
+            LOCK(&fop->fd->lock);
+
+            ctx = __ec_fd_get(fop->fd, fop->xl);
+            if ((ctx == NULL) || !ec_loc_from_loc(fop->xl, &ctx->loc,
+                &fop->loc[0]))
+            {
+                UNLOCK(&fop->fd->lock);
+
+                fop->error = EIO;
+
+                return EC_STATE_REPORT;
+            }
+
+            if (ctx->flags == 0)
+            {
+                ctx->flags = fop->int32;
+            }
+
+            UNLOCK(&fop->fd->lock);
+
+            if ((fop->int32 & O_ACCMODE) == O_WRONLY)
+            {
+                fop->int32 &= ~O_ACCMODE;
+                fop->int32 |= O_RDWR;
+            }
+
+        case EC_STATE_DISPATCH:
+            ec_dispatch_all(fop);
+
+            return EC_STATE_PREPARE_ANSWER;
+
+        case EC_STATE_PREPARE_ANSWER:
+            cbk = fop->answer;
+            if (cbk != NULL)
+            {
+                if (!ec_dict_combine(cbk, EC_COMBINE_XDATA))
+                {
+                    if (cbk->op_ret >= 0)
+                    {
+                        cbk->op_ret = -1;
+                        cbk->op_errno = EIO;
+                    }
+                }
+                if (cbk->op_ret < 0)
+                {
+                    ec_fop_set_error(fop, cbk->op_errno);
+                }
+                else
+                {
+                    ec_loc_prepare(fop->xl, &fop->loc[0], cbk->fd->inode,
+                                   NULL);
+
+                    LOCK(&fop->fd->lock);
+
+                    ctx = __ec_fd_get(fop->fd, fop->xl);
+                    if (ctx != NULL)
+                    {
+                        ctx->open |= cbk->mask;
+                    }
+
+                    UNLOCK(&fop->fd->lock);
+                }
+            }
+            else
+            {
+                ec_fop_set_error(fop, EIO);
+            }
+
+            return EC_STATE_REPORT;
+
+        case EC_STATE_REPORT:
+            cbk = fop->answer;
+
+            GF_ASSERT(cbk != NULL);
+
+            if (fop->cbks.open != NULL)
+            {
+                fop->cbks.open(fop->req_frame, fop, fop->xl, cbk->op_ret,
+                               cbk->op_errno, cbk->fd, cbk->xdata);
+            }
+
+            return EC_STATE_END;
+
+        case -EC_STATE_DISPATCH:
+        case -EC_STATE_PREPARE_ANSWER:
+        case -EC_STATE_REPORT:
+            GF_ASSERT(fop->error != 0);
+
+            if (fop->cbks.open != NULL)
+            {
+                fop->cbks.open(fop->req_frame, fop, fop->xl, -1, fop->error,
+                               NULL, NULL);
+            }
+
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_open(call_frame_t * frame, xlator_t * this, uintptr_t target,
+             int32_t minimum, fop_open_cbk_t func, void * data, loc_t * loc,
+             int32_t flags, fd_t * fd, dict_t * xdata)
+{
+    ec_cbk_t callback = { .open = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(OPEN) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_OPEN, EC_FLAG_UPDATE_FD,
+                               target, minimum, ec_wind_open, ec_manager_open,
+                               callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    fop->int32 = flags;
+
+    if (loc != NULL)
+    {
+        if (loc_copy(&fop->loc[0], loc) != 0)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to copy a location.");
+
+            goto out;
+        }
+    }
+    if (fd != NULL)
+    {
+        fop->fd = fd_ref(fd);
+        if (fop->fd == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "file descriptor.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL);
+    }
+}
+
+/* FOP: readlink */
+
+int32_t ec_combine_readlink(ec_fop_data_t * fop, ec_cbk_data_t * dst,
+                            ec_cbk_data_t * src)
+{
+    if (!ec_iatt_combine(dst->iatt, src->iatt, 1))
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching iatt in "
+                                             "answers of 'GF_FOP_READLINK'");
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int32_t ec_readlink_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                        int32_t op_ret, int32_t op_errno, const char * path,
+                        struct iatt * buf, dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    if (op_ret > 0)
+    {
+        ec_iatt_rebuild(fop->xl->private, buf, 1, 1);
+    }
+
+    if (!ec_dispatch_one_retry(fop, idx, op_ret, op_errno))
+    {
+        if (fop->cbks.readlink != NULL)
+        {
+            fop->cbks.readlink(fop->req_frame, fop, this, op_ret, op_errno,
+                               path, buf, xdata);
+        }
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_readlink(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_readlink_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->readlink,
+                      &fop->loc[0], fop->size, fop->xdata);
+}
+
+int32_t ec_manager_readlink(ec_fop_data_t * fop, int32_t state)
+{
+    switch (state)
+    {
+        case EC_STATE_INIT:
+        case EC_STATE_DISPATCH:
+            ec_dispatch_one(fop);
+
+            return EC_STATE_REPORT;
+
+        case -EC_STATE_REPORT:
+            if (fop->cbks.readlink != NULL)
+            {
+                fop->cbks.readlink(fop->req_frame, fop, fop->xl, -1,
+                                   fop->error, NULL, NULL, NULL);
+            }
+
+        case EC_STATE_REPORT:
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_readlink(call_frame_t * frame, xlator_t * this, uintptr_t target,
+                 int32_t minimum, fop_readlink_cbk_t func, void * data,
+                 loc_t * loc, size_t size, dict_t * xdata)
+{
+    ec_cbk_t callback = { .readlink = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(READLINK) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_READLINK, 0, target,
+                               minimum, ec_wind_readlink, ec_manager_readlink,
+                               callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    fop->size = size;
+
+    if (loc != NULL)
+    {
+        if (loc_copy(&fop->loc[0], loc) != 0)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to copy a location.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL, NULL);
+    }
+}
+
+/* FOP: readv */
+
+int32_t ec_readv_rebuild(ec_t * ec, ec_fop_data_t * fop, ec_cbk_data_t * cbk)
+{
+    ec_cbk_data_t * ans = NULL;
+    struct iobuf_pool * pool = NULL;
+    struct iobref * iobref = NULL;
+    struct iobuf * iobuf = NULL;
+    uint8_t * ptr = NULL, * buff = NULL;
+    size_t fsize = 0, size = 0, max = 0, slice = 0;
+    int32_t i = 0;
+
+    if (cbk->op_ret < 0)
+    {
+        goto out;
+    }
+
+    cbk->iatt[0].ia_size = fop->pre_size;
+
+    if (cbk->op_ret > 0)
+    {
+        struct iovec vector[cbk->int32 * cbk->count];
+        uint8_t * blocks[cbk->count];
+        uint32_t values[cbk->count];
+
+        fsize = cbk->op_ret;
+        size = fsize * ec->fragments;
+        ptr = GF_MALLOC(size + EC_BUFFER_ALIGN_SIZE - 1, gf_common_mt_char);
+        if (ptr == NULL)
+        {
+            goto out;
+        }
+        buff = GF_ALIGN_BUF(ptr, EC_BUFFER_ALIGN_SIZE);
+
+        iobref = iobref_new();
+        if (iobref == NULL)
+        {
+            goto out;
+        }
+
+        for (i = 0, ans = cbk; ans != NULL; i++, ans = ans->next)
+        {
+            values[i] = ans->idx;
+            blocks[i] = buff;
+            buff += ec_iov_copy_to(buff, ans->vector, ans->int32, 0, fsize);
+        }
+
+        pool = fop->xl->ctx->iobuf_pool;
+        max = iobpool_default_pagesize(pool) / ec->stripe_size;
+        max *= ec->fragment_size;
+        i = 0;
+        do
+        {
+            iobuf = iobuf_get(pool);
+            if (iobuf == NULL)
+            {
+                goto out;
+            }
+            if (iobref_add(iobref, iobuf) != 0)
+            {
+                goto out;
+            }
+
+            slice = fsize;
+            if (slice > max)
+            {
+                slice = max;
+            }
+            fsize -= slice;
+
+            vector[i].iov_base = iobuf->ptr;
+            vector[i].iov_len = ec_method_decode(slice, ec->fragments, values,
+                                                 blocks, iobuf->ptr);
+            i++;
+
+            iobuf_unref(iobuf);
+        } while (fsize > 0);
+
+        GF_FREE(ptr);
+        ptr = NULL;
+
+        vector[0].iov_base += fop->head;
+        vector[0].iov_len -= fop->head;
+
+        max = fop->offset * ec->fragments + size;
+        if (max > cbk->iatt[0].ia_size)
+        {
+            max = cbk->iatt[0].ia_size;
+        }
+        max -= fop->offset * ec->fragments + fop->head;
+        if (max > fop->user_size)
+        {
+            max = fop->user_size;
+        }
+        size -= fop->head;
+        while (size > max)
+        {
+            if (size - max >= vector[i - 1].iov_len)
+            {
+                size -= vector[--i].iov_len;
+            }
+            else
+            {
+                vector[i - 1].iov_len -= size - max;
+                size = max;
+            }
+        }
+
+        cbk->op_ret = size;
+        cbk->int32 = i;
+
+        iobref_unref(cbk->buffers);
+        cbk->buffers = iobref;
+
+        GF_FREE(cbk->vector);
+        cbk->vector = iov_dup(vector, i);
+        if (cbk->vector == NULL)
+        {
+            cbk->op_ret = -1;
+            cbk->op_errno = EIO;
+
+            return 0;
+        }
+    }
+
+    return 1;
+
+out:
+    if (iobuf != NULL)
+    {
+        iobuf_unref(iobuf);
+    }
+    if (iobref != NULL)
+    {
+        iobref_unref(iobref);
+    }
+    GF_FREE(ptr);
+
+    return 0;
+}
+
+int32_t ec_combine_readv(ec_fop_data_t * fop, ec_cbk_data_t * dst,
+                         ec_cbk_data_t * src)
+{
+    if (!ec_vector_compare(dst->vector, dst->int32, src->vector, src->int32))
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching vector in "
+                                             "answers of 'GF_FOP_READ'");
+
+        return 0;
+    }
+
+    if (!ec_iatt_combine(dst->iatt, src->iatt, 1))
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching iatt in "
+                                             "answers of 'GF_FOP_READ'");
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int32_t ec_readv_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                     int32_t op_ret, int32_t op_errno, struct iovec * vector,
+                     int32_t count, struct iatt * stbuf,
+                     struct iobref * iobref, dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    ec_t * ec = this->private;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_READ, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            cbk->int32 = count;
+
+            if (count > 0)
+            {
+                cbk->vector = iov_dup(vector, count);
+                if (cbk->vector == NULL)
+                {
+                    gf_log(this->name, GF_LOG_ERROR, "Failed to duplicate a "
+                                                     "vector list.");
+
+                    goto out;
+                }
+                cbk->int32 = count;
+            }
+            if (stbuf != NULL)
+            {
+                cbk->iatt[0] = *stbuf;
+            }
+            if (iobref != NULL)
+            {
+                cbk->buffers = iobref_ref(iobref);
+                if (cbk->buffers == NULL)
+                {
+                    gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                     "buffer.");
+
+                    goto out;
+                }
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        if ((op_ret > 0) && ((op_ret % ec->fragment_size) != 0))
+        {
+            cbk->op_ret = -1;
+            cbk->op_errno = EIO;
+        }
+
+        ec_combine(cbk, ec_combine_readv);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_readv(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_readv_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->readv, fop->fd,
+                      fop->size, fop->offset, fop->uint32, fop->xdata);
+}
+
+int32_t ec_manager_readv(ec_fop_data_t * fop, int32_t state)
+{
+    ec_cbk_data_t * cbk;
+
+    switch (state)
+    {
+        case EC_STATE_INIT:
+            fop->user_size = fop->size;
+            fop->head = ec_adjust_offset(fop->xl->private, &fop->offset, 1);
+            fop->size = ec_adjust_size(fop->xl->private, fop->size + fop->head,
+                                       1);
+
+        case EC_STATE_LOCK:
+            ec_lock_fd(fop, fop->fd);
+
+            return EC_STATE_GET_SIZE_AND_VERSION;
+
+        case EC_STATE_GET_SIZE_AND_VERSION:
+            ec_get_size_version(fop);
+
+            return EC_STATE_DISPATCH;
+
+        case EC_STATE_DISPATCH:
+            ec_dispatch_min(fop);
+
+            return EC_STATE_PREPARE_ANSWER;
+
+        case EC_STATE_PREPARE_ANSWER:
+            cbk = fop->answer;
+            if (cbk != NULL)
+            {
+                if (!ec_dict_combine(cbk, EC_COMBINE_XDATA))
+                {
+                    if (cbk->op_ret >= 0)
+                    {
+                        cbk->op_ret = -1;
+                        cbk->op_errno = EIO;
+                    }
+                }
+                if (cbk->op_ret < 0)
+                {
+                    ec_fop_set_error(fop, cbk->op_errno);
+                }
+                else
+                {
+                    ec_iatt_rebuild(fop->xl->private, cbk->iatt, 1,
+                                    cbk->count);
+
+                    if (!ec_readv_rebuild(fop->xl->private, fop, cbk))
+                    {
+                        ec_fop_set_error(fop, EIO);
+                    }
+                }
+            }
+            else
+            {
+                ec_fop_set_error(fop, EIO);
+            }
+
+            return EC_STATE_REPORT;
+
+        case EC_STATE_REPORT:
+            cbk = fop->answer;
+
+            GF_ASSERT(cbk != NULL);
+
+            if (fop->cbks.readv != NULL)
+            {
+                fop->cbks.readv(fop->req_frame, fop, fop->xl, cbk->op_ret,
+                                cbk->op_errno, cbk->vector, cbk->int32,
+                                &cbk->iatt[0], cbk->buffers, cbk->xdata);
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_LOCK:
+        case -EC_STATE_GET_SIZE_AND_VERSION:
+        case -EC_STATE_DISPATCH:
+        case -EC_STATE_PREPARE_ANSWER:
+        case -EC_STATE_REPORT:
+            GF_ASSERT(fop->error != 0);
+
+            if (fop->cbks.readv != NULL)
+            {
+                fop->cbks.readv(fop->req_frame, fop, fop->xl, -1, fop->error,
+                                NULL, 0, NULL, NULL, NULL);
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_UNLOCK:
+        case EC_STATE_UNLOCK:
+            ec_unlock(fop);
+
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_readv(call_frame_t * frame, xlator_t * this, uintptr_t target,
+              int32_t minimum, fop_readv_cbk_t func, void * data, fd_t * fd,
+              size_t size, off_t offset, uint32_t flags, dict_t * xdata)
+{
+    ec_cbk_t callback = { .readv = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(READ) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_READ, EC_FLAG_UPDATE_FD,
+                               target, minimum, ec_wind_readv,
+                               ec_manager_readv, callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    fop->size = size;
+    fop->offset = offset;
+    fop->uint32 = flags;
+
+    if (fd != NULL)
+    {
+        fop->fd = fd_ref(fd);
+        if (fop->fd == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "file descriptor.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, 0, NULL, NULL, NULL);
+    }
+}
+
+/* FOP: stat */
+
+int32_t ec_combine_stat(ec_fop_data_t * fop, ec_cbk_data_t * dst,
+                        ec_cbk_data_t * src)
+{
+    if (!ec_iatt_combine(dst->iatt, src->iatt, 1))
+    {
+        gf_log(fop->xl->name, GF_LOG_NOTICE, "Mismatching iatt in "
+                                             "answers of 'GF_FOP_STAT'");
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int32_t ec_stat_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                    int32_t op_ret, int32_t op_errno, struct iatt * buf,
+                    dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_STAT, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            if (buf != NULL)
+            {
+                cbk->iatt[0] = *buf;
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        ec_combine(cbk, ec_combine_stat);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_stat(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_stat_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->stat,
+                      &fop->loc[0], fop->xdata);
+}
+
+int32_t ec_manager_stat(ec_fop_data_t * fop, int32_t state)
+{
+    ec_cbk_data_t * cbk;
+
+    switch (state)
+    {
+        case EC_STATE_INIT:
+        case EC_STATE_LOCK:
+            ec_lock_inode(fop, &fop->loc[0]);
+
+            return EC_STATE_GET_SIZE_AND_VERSION;
+
+        case EC_STATE_GET_SIZE_AND_VERSION:
+            ec_get_size_version(fop);
+
+            return EC_STATE_DISPATCH;
+
+        case EC_STATE_DISPATCH:
+            ec_dispatch_all(fop);
+
+            return EC_STATE_PREPARE_ANSWER;
+
+        case EC_STATE_PREPARE_ANSWER:
+            cbk = fop->answer;
+            if (cbk != NULL)
+            {
+                if (!ec_dict_combine(cbk, EC_COMBINE_XDATA))
+                {
+                    if (cbk->op_ret >= 0)
+                    {
+                        cbk->op_ret = -1;
+                        cbk->op_errno = EIO;
+                    }
+                }
+                if (cbk->op_ret < 0)
+                {
+                    ec_fop_set_error(fop, cbk->op_errno);
+                }
+                else
+                {
+                    ec_iatt_rebuild(fop->xl->private, cbk->iatt, 1,
+                                    cbk->count);
+
+                    cbk->iatt[0].ia_size = fop->pre_size;
+                }
+            }
+            else
+            {
+                ec_fop_set_error(fop, EIO);
+            }
+
+            return EC_STATE_REPORT;
+
+        case EC_STATE_REPORT:
+            cbk = fop->answer;
+
+            GF_ASSERT(cbk != NULL);
+
+            if (fop->fd == NULL)
+            {
+                if (fop->cbks.stat != NULL)
+                {
+                    fop->cbks.stat(fop->req_frame, fop, fop->xl, cbk->op_ret,
+                                   cbk->op_errno, &cbk->iatt[0], cbk->xdata);
+                }
+            }
+            else
+            {
+                if (fop->cbks.fstat != NULL)
+                {
+                    fop->cbks.fstat(fop->req_frame, fop, fop->xl, cbk->op_ret,
+                                    cbk->op_errno, &cbk->iatt[0], cbk->xdata);
+                }
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_LOCK:
+        case -EC_STATE_GET_SIZE_AND_VERSION:
+        case -EC_STATE_DISPATCH:
+        case -EC_STATE_PREPARE_ANSWER:
+        case -EC_STATE_REPORT:
+            GF_ASSERT(fop->error != 0);
+
+            if (fop->fd == NULL)
+            {
+                if (fop->cbks.stat != NULL)
+                {
+                    fop->cbks.stat(fop->req_frame, fop, fop->xl, -1,
+                                   fop->error, NULL, NULL);
+                }
+            }
+            else
+            {
+                if (fop->cbks.fstat != NULL)
+                {
+                    fop->cbks.fstat(fop->req_frame, fop, fop->xl, -1,
+                                    fop->error, NULL, NULL);
+                }
+            }
+
+            return EC_STATE_UNLOCK;
+
+        case -EC_STATE_UNLOCK:
+        case EC_STATE_UNLOCK:
+            ec_unlock(fop);
+
+            return EC_STATE_END;
+
+        default:
+            gf_log(fop->xl->name, GF_LOG_ERROR, "Unhandled state %d for %s",
+                   state, ec_fop_name(fop->id));
+
+            return EC_STATE_END;
+    }
+}
+
+void ec_stat(call_frame_t * frame, xlator_t * this, uintptr_t target,
+             int32_t minimum, fop_stat_cbk_t func, void * data, loc_t * loc,
+             dict_t * xdata)
+{
+    ec_cbk_t callback = { .stat = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(STAT) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_STAT,
+                               EC_FLAG_UPDATE_LOC_INODE, target, minimum,
+                               ec_wind_stat, ec_manager_stat, callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    if (loc != NULL)
+    {
+        if (loc_copy(&fop->loc[0], loc) != 0)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to copy a location.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL);
+    }
+}
+
+/* FOP: fstat */
+
+int32_t ec_fstat_cbk(call_frame_t * frame, void * cookie, xlator_t * this,
+                     int32_t op_ret, int32_t op_errno, struct iatt * buf,
+                     dict_t * xdata)
+{
+    ec_fop_data_t * fop = NULL;
+    ec_cbk_data_t * cbk = NULL;
+    int32_t idx = (int32_t)(uintptr_t)cookie;
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame->local, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = frame->local;
+
+    ec_trace("CBK", fop, "idx=%d, frame=%p, op_ret=%d, op_errno=%d", idx,
+             frame, op_ret, op_errno);
+
+    cbk = ec_cbk_data_allocate(frame, this, fop, GF_FOP_FSTAT, idx, op_ret,
+                               op_errno);
+    if (cbk != NULL)
+    {
+        if (op_ret >= 0)
+        {
+            if (buf != NULL)
+            {
+                cbk->iatt[0] = *buf;
+            }
+        }
+        if (xdata != NULL)
+        {
+            cbk->xdata = dict_ref(xdata);
+            if (cbk->xdata == NULL)
+            {
+                gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                                 "dictionary.");
+
+                goto out;
+            }
+        }
+
+        ec_combine(cbk, ec_combine_stat);
+    }
+
+out:
+    if (fop != NULL)
+    {
+        ec_complete(fop);
+    }
+
+    return 0;
+}
+
+void ec_wind_fstat(ec_t * ec, ec_fop_data_t * fop, int32_t idx)
+{
+    ec_trace("WIND", fop, "idx=%d", idx);
+
+    STACK_WIND_COOKIE(fop->frame, ec_fstat_cbk, (void *)(uintptr_t)idx,
+                      ec->xl_list[idx], ec->xl_list[idx]->fops->fstat, fop->fd,
+                      fop->xdata);
+}
+
+void ec_fstat(call_frame_t * frame, xlator_t * this, uintptr_t target,
+              int32_t minimum, fop_fstat_cbk_t func, void * data, fd_t * fd,
+              dict_t * xdata)
+{
+    ec_cbk_t callback = { .fstat = func };
+    ec_fop_data_t * fop = NULL;
+    int32_t error = EIO;
+
+    gf_log("ec", GF_LOG_TRACE, "EC(FSTAT) %p", frame);
+
+    VALIDATE_OR_GOTO(this, out);
+    GF_VALIDATE_OR_GOTO(this->name, frame, out);
+    GF_VALIDATE_OR_GOTO(this->name, this->private, out);
+
+    fop = ec_fop_data_allocate(frame, this, GF_FOP_FSTAT,
+                               EC_FLAG_UPDATE_FD_INODE, target, minimum,
+                               ec_wind_fstat, ec_manager_stat, callback, data);
+    if (fop == NULL)
+    {
+        goto out;
+    }
+
+    if (fd != NULL)
+    {
+        fop->fd = fd_ref(fd);
+        if (fop->fd == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "file descriptor.");
+
+            goto out;
+        }
+    }
+    if (xdata != NULL)
+    {
+        fop->xdata = dict_ref(xdata);
+        if (fop->xdata == NULL)
+        {
+            gf_log(this->name, GF_LOG_ERROR, "Failed to reference a "
+                                             "dictionary.");
+
+            goto out;
+        }
+    }
+
+    error = 0;
+
+out:
+    if (fop != NULL)
+    {
+        ec_manager(fop, error);
+    }
+    else
+    {
+        func(frame, NULL, this, -1, EIO, NULL, NULL);
+    }
+}