locks: Added a getxattr interface to clear locks on a given inode.

getxattr returns a summary of no. of inodelks/entrylks cleared.
cmd_structure: trusted.glusterfs.clrlk.t<type>.k<kind>[.{range|basename}]
where,
type = "inode"| "entry"| "posix"
kind = "granted"| "blocked" | "all"
range = off,a-b, where a, b = 'start', 'len' from offset 'off'

Change-Id: I8a771530531030a9d4268643bc6823786ccb51f2
BUG: 789858
Signed-off-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-on: http://review.gluster.com/2551
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

7 files changed, 785 insertions, 36 deletions

diff --git a/libglusterfs/src/glusterfs.h b/libglusterfs/src/glusterfs.h
index 680f0de98f2..8360077ecf7 100644
--- a/libglusterfs/src/glusterfs.h
+++ b/libglusterfs/src/glusterfs.h
@@ -79,6 +79,7 @@
 #define ZR_STRICT_VOLFILE_CHECK "strict-volfile-check"
 #define ZR_DUMP_FUSE            "dump-fuse"
 
+#define GF_XATTR_CLRLK_CMD      "glusterfs.clrlk"
 #define GF_XATTR_PATHINFO_KEY   "trusted.glusterfs.pathinfo"
 #define GF_XATTR_LINKINFO_KEY   "trusted.distribute.linkinfo"
 #define GFID_XATTR_KEY "trusted.gfid"
diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index b0f7b38f3fd..a5dee65f621 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -808,7 +808,6 @@ afr_local_transaction_cleanup (afr_local_t *local, xlator_t *this)
 
         GF_FREE (local->transaction.pre_op);
         GF_FREE (local->transaction.child_errno);
-        GF_FREE (local->child_errno);
         GF_FREE (local->transaction.eager_lock);
 
         GF_FREE (local->transaction.basename);
@@ -845,6 +844,9 @@ afr_local_cleanup (afr_local_t *local, xlator_t *this)
         if (local->child_up)
                 GF_FREE (local->child_up);
 
+        if (local->child_errno)
+                GF_FREE (local->child_errno);
+
         if (local->fresh_children)
                 GF_FREE (local->fresh_children);
 
@@ -3592,8 +3594,8 @@ afr_local_init (afr_local_t *local, afr_private_t *priv, int32_t *op_errno)
         local->op_ret = -1;
         local->op_errno = EUCLEAN;
 
-        local->child_up = GF_CALLOC (sizeof (*local->child_up),
-                                     priv->child_count,
+        local->child_up = GF_CALLOC (priv->child_count,
+                                     sizeof (*local->child_up),
                                      gf_afr_mt_char);
         if (!local->child_up) {
                 if (op_errno)
@@ -3611,6 +3613,16 @@ afr_local_init (afr_local_t *local, afr_private_t *priv, int32_t *op_errno)
                         *op_errno = ENOTCONN;
                 goto out;
         }
+
+        local->child_errno = GF_CALLOC (priv->child_count,
+                                        sizeof (*local->child_errno),
+                                        gf_afr_mt_int32_t);
+        if (!local->child_errno) {
+                if (op_errno)
+                        *op_errno = ENOMEM;
+                goto out;
+        }
+
         ret = 0;
 out:
         return ret;
@@ -3711,12 +3723,6 @@ afr_transaction_local_init (afr_local_t *local, xlator_t *this)
         local->first_up_child = afr_first_up_child (local->child_up,
                                                     priv->child_count);
 
-        local->child_errno = GF_CALLOC (sizeof (*local->child_errno),
-                                        priv->child_count,
-                                        gf_afr_mt_int32_t);
-        if (!local->child_errno)
-                goto out;
-
         local->transaction.eager_lock =
                 GF_CALLOC (sizeof (*local->transaction.eager_lock),
                            priv->child_count,
diff --git a/xlators/cluster/afr/src/afr-inode-read.c b/xlators/cluster/afr/src/afr-inode-read.c
index 0ef0f4f8642..ec0acbd3b0b 100644
--- a/xlators/cluster/afr/src/afr-inode-read.c
+++ b/xlators/cluster/afr/src/afr-inode-read.c
@@ -632,6 +632,101 @@ afr_getxattr_unwind (call_frame_t *frame,
 }
 
 int32_t
+afr_getxattr_clrlk_cbk (call_frame_t *frame, void *cookie,
+                        xlator_t *this, int32_t op_ret, int32_t op_errno,
+                        dict_t *dict)
+{
+        afr_local_t     *local                  = NULL;
+        afr_private_t   *priv                   = NULL;
+        xlator_t        **children              = NULL;
+        dict_t          *xattr                  = NULL;
+        char            *tmp_report             = NULL;
+        char            lk_summary[1024]        = {0,};
+        int             serz_len                = 0;
+        int32_t         callcnt                 = 0;
+        long int        cky                     = 0;
+        int             ret                     = 0;
+
+        priv     = this->private;
+        children = priv->children;
+
+        local = frame->local;
+        cky = (long) cookie;
+
+        LOCK (&frame->lock);
+        {
+                callcnt = --local->call_count;
+
+                if (!local->dict)
+                        local->dict = dict_new ();
+                if (local->dict) {
+                        ret = dict_get_str (dict, local->cont.getxattr.name,
+                                            &tmp_report);
+                        if (ret)
+                                goto unlock;
+                        ret = dict_set_str (local->dict,
+                                            children[cky]->name,
+                                            tmp_report);
+                        if (ret)
+                                goto unlock;
+                }
+                if (op_ret == -1)
+                        local->child_errno[cky] = op_errno;
+        }
+unlock:
+        UNLOCK (&frame->lock);
+
+        if (!callcnt) {
+                xattr = dict_new ();
+                if (!xattr) {
+                        op_ret = -1;
+                        op_errno = ENOMEM;
+                        goto unwind;
+                }
+                ret = dict_serialize_value_with_delim (local->dict,
+                                                       lk_summary,
+                                                       &serz_len, '\n');
+                if (ret) {
+                        op_ret = -1;
+                        op_errno = ENOMEM;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Error serializing dictionary");
+                        goto unwind;
+                }
+                if (serz_len == -1)
+                        snprintf (lk_summary, sizeof (lk_summary),
+                                  "No locks cleared.");
+                ret = dict_set_dynstr (xattr, local->cont.getxattr.name,
+                                       gf_strdup (lk_summary));
+                if (ret) {
+                        op_ret = -1;
+                        op_errno = ENOMEM;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Error setting dictionary");
+                        goto unwind;
+                }
+
+        unwind:
+                // Updating child_errno with more recent 'events'
+                local->child_errno[cky] = op_errno;
+                op_errno = afr_resultant_errno_get (NULL, local->child_errno,
+                                                    priv->child_count);
+                AFR_STACK_UNWIND (getxattr, frame, op_ret, op_errno, xattr);
+
+                if (local->dict)
+                        dict_unref (local->dict);
+
+                if (local->child_errno)
+                        GF_FREE (local->child_errno);
+
+                if (xattr)
+                        dict_unref (xattr);
+        }
+
+        return ret;
+}
+
+int32_t
 afr_getxattr_pathinfo_cbk (call_frame_t *frame, void *cookie,
                            xlator_t *this, int32_t op_ret, int32_t op_errno,
                            dict_t *dict)
@@ -735,20 +830,69 @@ afr_getxattr_pathinfo_cbk (call_frame_t *frame, void *cookie,
         return ret;
 }
 
+static gf_boolean_t
+afr_is_special_xattr (const char *name, fop_getxattr_cbk_t *cbk)
+{
+        gf_boolean_t    is_spl = _gf_true;
+
+        GF_ASSERT (cbk);
+        if (!cbk) {
+                is_spl = _gf_false;
+                goto out;
+        }
+
+        if (!strcmp (name, GF_XATTR_PATHINFO_KEY))
+                *cbk = afr_getxattr_pathinfo_cbk;
+
+        else if (!strcmp (name, GF_XATTR_CLRLK_CMD))
+                *cbk = afr_getxattr_clrlk_cbk;
+        else
+                is_spl = _gf_false;
+
+out:
+        return is_spl;
+}
+
+static void
+afr_getxattr_frm_all_children (xlator_t *this, call_frame_t *frame,
+                               const char *name, loc_t *loc,
+                               fop_getxattr_cbk_t cbk)
+{
+        afr_private_t   *priv           = NULL;
+        afr_local_t     *local          = NULL;
+        xlator_t        **children      = NULL;
+        int             i               = 0;
+
+        priv     = this->private;
+        children = priv->children;
+
+        local = frame->local;
+        local->call_count = priv->child_count;
+
+        for (i = 0; i < priv->child_count; i++) {
+                STACK_WIND_COOKIE (frame, cbk,
+                                   (void *) (long) i,
+                                   children[i], children[i]->fops->getxattr,
+                                   loc, name);
+        }
+        return;
+}
+
 int32_t
 afr_getxattr (call_frame_t *frame, xlator_t *this,
               loc_t *loc, const char *name)
 {
-        afr_private_t   *priv         = NULL;
-        xlator_t        **children    = NULL;
-        int             call_child    = 0;
-        afr_local_t     *local        = NULL;
-        xlator_list_t   *trav         = NULL;
-        xlator_t        **sub_volumes = NULL;
-        int             i             = 0;
-        int32_t         op_errno      = 0;
-        int32_t         read_child    = -1;
-        int             ret           = -1;
+        afr_private_t           *priv         = NULL;
+        xlator_t                **children    = NULL;
+        int                     call_child    = 0;
+        afr_local_t             *local        = NULL;
+        xlator_list_t           *trav         = NULL;
+        xlator_t                **sub_volumes = NULL;
+        int                     i             = 0;
+        int32_t                 op_errno      = 0;
+        int32_t                 read_child    = -1;
+        int                     ret           = -1;
+        fop_getxattr_cbk_t      cbk           = NULL;
 
 
         VALIDATE_OR_GOTO (frame, out);
@@ -814,17 +958,9 @@ afr_getxattr (call_frame_t *frame, xlator_t *this,
                  * if we are doing getxattr with pathinfo as the key then we
                  * collect information from all childs
                  */
-                if (strncmp (name, GF_XATTR_PATHINFO_KEY,
-                             strlen (GF_XATTR_PATHINFO_KEY)) == 0) {
-
-                        local->call_count = priv->child_count;
-                        for (i = 0; i < priv->child_count; i++) {
-                                STACK_WIND_COOKIE (frame, afr_getxattr_pathinfo_cbk,
-                                                   (void *) (long) i,
-                                                   children[i], children[i]->fops->getxattr,
-                                                   loc, name);
-                        }
-
+                if (afr_is_special_xattr (name, &cbk)) {
+                        afr_getxattr_frm_all_children (this, frame, name,
+                                                       loc, cbk);
                         return 0;
                 }
 
diff --git a/xlators/features/locks/src/Makefile.am b/xlators/features/locks/src/Makefile.am
index 53dd3aa5da5..e39676826b4 100644
--- a/xlators/features/locks/src/Makefile.am
+++ b/xlators/features/locks/src/Makefile.am
@@ -3,12 +3,14 @@ xlatordir = $(libdir)/glusterfs/$(PACKAGE_VERSION)/xlator/features
 
 locks_la_LDFLAGS = -module -avoidversion
 
-locks_la_SOURCES = common.c posix.c entrylk.c inodelk.c reservelk.c
-locks_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la 
+locks_la_SOURCES = common.c posix.c entrylk.c inodelk.c reservelk.c \
+		   clear.c
+locks_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la
 
-noinst_HEADERS = locks.h common.h locks-mem-types.h
+noinst_HEADERS = locks.h common.h locks-mem-types.h clear.h
 
-AM_CFLAGS = -fPIC -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -Wall -fno-strict-aliasing -D$(GF_HOST_OS) \
+AM_CFLAGS = -fPIC -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -Wall \
+	-fno-strict-aliasing -D$(GF_HOST_OS) \
 	-I$(top_srcdir)/libglusterfs/src $(GF_CFLAGS) -shared -nostartfiles
 
 CLEANFILES = 
@@ -17,4 +19,4 @@ uninstall-local:
 	rm -f $(DESTDIR)$(xlatordir)/posix-locks.so
 
 install-data-hook:
-	ln -sf locks.so $(DESTDIR)$(xlatordir)/posix-locks.so
\ No newline at end of file
+	ln -sf locks.so $(DESTDIR)$(xlatordir)/posix-locks.so
diff --git a/xlators/features/locks/src/clear.c b/xlators/features/locks/src/clear.c
new file mode 100644
index 00000000000..a7b2455e33c
--- /dev/null
+++ b/xlators/features/locks/src/clear.c
@@ -0,0 +1,409 @@
+/*
+  Copyright (c) 2006-2011 Gluster, Inc. <http://www.gluster.com>
+  This file is part of GlusterFS.
+
+  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.
+
+  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 this program.  If not, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <pthread.h>
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "glusterfs.h"
+#include "compat.h"
+#include "xlator.h"
+#include "inode.h"
+#include "logging.h"
+#include "common-utils.h"
+
+#include "locks.h"
+#include "common.h"
+#include "statedump.h"
+#include "clear.h"
+
+int
+clrlk_get_kind (char *kind)
+{
+        char  *clrlk_kinds[CLRLK_KIND_MAX] = {"dummy", "blocked", "granted",
+                                              "all"};
+        int   ret_kind                     = CLRLK_KIND_MAX;
+        int   i                            = 0;
+
+        for (i = CLRLK_BLOCKED; i < CLRLK_KIND_MAX; i++) {
+                if (!strcmp (clrlk_kinds[i], kind)) {
+                        ret_kind = i;
+                        break;
+                }
+        }
+
+        return ret_kind;
+}
+
+int
+clrlk_get_type (char *type)
+{
+        char    *clrlk_types[CLRLK_TYPE_MAX]    = {"inode", "entry", "posix"};
+        int     ret_type                        = CLRLK_TYPE_MAX;
+        int     i                               = 0;
+
+        for (i = CLRLK_INODE; i < CLRLK_TYPE_MAX; i++) {
+                if (!strcmp (clrlk_types[i], type)) {
+                        ret_type = i;
+                        break;
+                }
+        }
+
+        return ret_type;
+}
+
+int
+clrlk_get_lock_range (char *range_str, struct gf_flock *ulock,
+                      gf_boolean_t *chk_range)
+{
+        int     ret     =       -1;
+
+        if (!chk_range)
+                goto out;
+
+        if (!range_str) {
+                ret = 0;
+                *chk_range = _gf_false;
+                goto out;
+        }
+
+        if (sscanf (range_str, "%hd,%"PRId64"-""%"PRId64, &ulock->l_whence,
+                    &ulock->l_start, &ulock->l_len) != 3) {
+                goto out;
+        }
+
+        ret = 0;
+        *chk_range = _gf_true;
+out:
+        return ret;
+}
+
+int
+clrlk_parse_args (const char* cmd, clrlk_args *args)
+{
+        char            *opts           = NULL;
+        char            *cur            = NULL;
+        char            *tok            = NULL;
+        char            *sptr           = NULL;
+        char            *free_ptr       = NULL;
+        char            kw[KW_MAX]     = {[KW_TYPE]     = 't',
+                                          [KW_KIND]     = 'k',
+                                          };
+        int             ret             = -1;
+        int             i               = 0;
+
+        GF_ASSERT (cmd);
+        free_ptr = opts = GF_CALLOC (1, strlen (cmd), gf_common_mt_char);
+        if (!opts)
+                goto out;
+
+        if (sscanf (cmd, GF_XATTR_CLRLK_CMD".%s", opts) < 1) {
+                ret = -1;
+                goto out;
+        }
+
+        /*clr_lk_prefix.ttype.kkind.args, args - type specific*/
+        cur = opts;
+        for (i = 0; i < KW_MAX && (tok = strtok_r (cur, ".", &sptr));
+             cur = NULL, i++) {
+                if (tok[0] != kw[i]) {
+                        ret = -1;
+                        goto out;
+                }
+                if (i == KW_TYPE)
+                        args->type = clrlk_get_type (tok+1);
+                if (i == KW_KIND)
+                        args->kind = clrlk_get_kind (tok+1);
+        }
+
+        if ((args->type == CLRLK_TYPE_MAX) || (args->kind == CLRLK_KIND_MAX))
+                goto out;
+
+        /*optional args*/
+        tok = strtok_r (NULL, ".", &sptr);
+        if (tok)
+                args->opts = gf_strdup (tok);
+
+        ret = 0;
+out:
+        if (free_ptr)
+                GF_FREE (free_ptr);
+        return ret;
+}
+
+int
+clrlk_clear_posixlk (xlator_t *this, pl_inode_t *pl_inode, clrlk_args *args,
+                     int *blkd, int *granted, int *op_errno)
+{
+        posix_lock_t            *plock          = NULL;
+        posix_lock_t            *tmp            = NULL;
+        struct gf_flock         ulock           = {0, };
+        int                     ret             = -1;
+        int                     bcount          = 0;
+        int                     gcount          = 0;
+        gf_boolean_t            chk_range       = _gf_false;
+
+        if (clrlk_get_lock_range (args->opts, &ulock, &chk_range)) {
+                *op_errno = EINVAL;
+                goto out;
+        }
+
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                list_for_each_entry_safe (plock, tmp, &pl_inode->ext_list,
+                                          list) {
+                        if ((plock->blocked &&
+                             !(args->kind & CLRLK_BLOCKED)) ||
+                            (!plock->blocked &&
+                             !(args->kind & CLRLK_GRANTED)))
+                                continue;
+
+                        if (chk_range &&
+                            (plock->user_flock.l_whence != ulock.l_whence
+                            || plock->user_flock.l_start != ulock.l_start
+                            || plock->user_flock.l_len != ulock.l_len))
+                                continue;
+
+                        list_del_init (&plock->list);
+                        if (plock->blocked) {
+                                bcount++;
+                                pl_trace_out (this, plock->frame, NULL, NULL,
+                                              F_SETLKW, &plock->user_flock,
+                                              -1, EAGAIN, NULL);
+
+                                STACK_UNWIND (plock->frame, -1, EAGAIN,
+                                              &plock->user_flock);
+
+                        } else {
+                                gcount++;
+                        }
+                        GF_FREE (plock);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+        grant_blocked_locks (this, pl_inode);
+out:
+        *blkd    = bcount;
+        *granted = gcount;
+        return ret;
+}
+
+/* Returns 0 on success and -1 on failure */
+int
+clrlk_clear_inodelk (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
+                     clrlk_args *args, int *blkd, int *granted, int *op_errno)
+{
+        pl_inode_lock_t         *ilock          = NULL;
+        pl_inode_lock_t         *tmp            = NULL;
+        struct gf_flock         ulock           = {0, };
+        int                     ret             = -1;
+        int                     bcount          = 0;
+        int                     gcount          = 0;
+        gf_boolean_t            chk_range       = _gf_false;
+
+        if (clrlk_get_lock_range (args->opts, &ulock, &chk_range)) {
+                *op_errno = EINVAL;
+                goto out;
+        }
+
+        if (args->kind & CLRLK_BLOCKED)
+                goto blkd;
+
+        if (args->kind & CLRLK_GRANTED)
+                goto granted;
+
+blkd:
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                list_for_each_entry_safe (ilock, tmp, &dom->blocked_inodelks,
+                                          blocked_locks) {
+                        if (chk_range &&
+                            (ilock->user_flock.l_whence != ulock.l_whence
+                            || ilock->user_flock.l_start != ulock.l_start
+                            || ilock->user_flock.l_len != ulock.l_len))
+                                continue;
+
+                        bcount++;
+                        list_del_init (&ilock->list);
+                        pl_trace_out (this, ilock->frame, NULL, NULL, F_SETLKW,
+                                      &ilock->user_flock, -1, EAGAIN,
+                                      ilock->volume);
+                        STACK_UNWIND_STRICT (inodelk, ilock->frame, -1,
+                                             EAGAIN);
+                        GF_FREE (ilock);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        if (!(args->kind & CLRLK_GRANTED)) {
+                ret = 0;
+                goto out;
+        }
+
+granted:
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                list_for_each_entry_safe (ilock, tmp, &dom->inodelk_list,
+                                          list) {
+                        if (chk_range &&
+                            (ilock->user_flock.l_whence != ulock.l_whence
+                            || ilock->user_flock.l_start != ulock.l_start
+                            || ilock->user_flock.l_len != ulock.l_len))
+                                continue;
+
+                        gcount++;
+                        list_del_init (&ilock->list);
+                        GF_FREE (ilock);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        grant_blocked_inode_locks (this, pl_inode, dom);
+        ret = 0;
+out:
+        *blkd    = bcount;
+        *granted = gcount;
+        return ret;
+}
+
+/* Returns 0 on success and -1 on failure */
+int
+clrlk_clear_entrylk (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
+                     clrlk_args *args, int *blkd, int *granted, int *op_errno)
+{
+        pl_entry_lock_t         *elock          = NULL;
+        pl_entry_lock_t         *tmp            = NULL;
+        struct list_head        removed         = {0};
+        int                     bcount          = 0;
+        int                     gcount          = 0;
+        int                     ret             = -1;
+
+        if (args->kind & CLRLK_BLOCKED)
+                goto blkd;
+
+        if (args->kind & CLRLK_GRANTED)
+                goto granted;
+
+blkd:
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                list_for_each_entry_safe (elock, tmp, &dom->blocked_entrylks,
+                                          blocked_locks) {
+                        if (args->opts &&
+                            strncmp (elock->basename, args->opts,
+                                     strlen (elock->basename)))
+                                continue;
+
+                        bcount++;
+                        list_del_init (&elock->domain_list);
+                        STACK_UNWIND_STRICT (entrylk, elock->frame, -1,
+                                             EAGAIN);
+                        GF_FREE ((char *) elock->basename);
+                        GF_FREE (elock);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        if (!(args->kind & CLRLK_GRANTED)) {
+                ret = 0;
+                goto out;
+        }
+
+granted:
+        INIT_LIST_HEAD (&removed);
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                list_for_each_entry_safe (elock, tmp, &dom->entrylk_list,
+                                          domain_list) {
+                        if (!elock->basename)
+                                continue;
+
+                        if (args->opts &&
+                            strncmp (elock->basename, args->opts,
+                                     strlen (elock->basename)))
+                                continue;
+
+                        gcount++;
+                        list_del_init (&elock->domain_list);
+                        list_add_tail (&elock->domain_list, &removed);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        list_for_each_entry_safe (elock, tmp, &removed, domain_list) {
+                grant_blocked_entry_locks (this, pl_inode, elock, dom);
+        }
+
+        ret = 0;
+out:
+        *blkd    = bcount;
+        *granted = gcount;
+        return ret;
+}
+
+int
+clrlk_clear_lks_in_all_domains (xlator_t *this, pl_inode_t *pl_inode,
+                          clrlk_args *args, int *blkd, int *granted,
+                          int *op_errno)
+{
+        pl_dom_list_t   *dom            = NULL;
+        int             ret             = -1;
+        int             tmp_bcount      = 0;
+        int             tmp_gcount      = 0;
+
+        if (list_empty (&pl_inode->dom_list)) {
+                ret = 0;
+                goto out;
+        }
+
+        list_for_each_entry (dom, &pl_inode->dom_list, inode_list) {
+                tmp_bcount = tmp_gcount = 0;
+
+                switch (args->type)
+                {
+                case CLRLK_INODE:
+                        ret = clrlk_clear_inodelk (this, pl_inode, dom, args,
+                                             &tmp_bcount, &tmp_gcount,
+                                             op_errno);
+                        if (ret)
+                                goto out;
+                        break;
+                case CLRLK_ENTRY:
+                        ret = clrlk_clear_entrylk (this, pl_inode, dom, args,
+                                             &tmp_bcount, &tmp_gcount,
+                                             op_errno);
+                        if (ret)
+                                goto out;
+                        break;
+                }
+
+                *blkd    += tmp_bcount;
+                *granted += tmp_gcount;
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
diff --git a/xlators/features/locks/src/clear.h b/xlators/features/locks/src/clear.h
new file mode 100644
index 00000000000..95572a9710e
--- /dev/null
+++ b/xlators/features/locks/src/clear.h
@@ -0,0 +1,86 @@
+/*
+  Copyright (c) 2006-2011 Gluster, Inc. <http://www.gluster.com>
+  This file is part of GlusterFS.
+
+  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.
+
+  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 this program.  If not, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CLEAR_H__
+#define __CLEAR_H__
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "compat-errno.h"
+#include "stack.h"
+#include "call-stub.h"
+#include "locks.h"
+
+typedef enum {
+        CLRLK_INODE,
+        CLRLK_ENTRY,
+        CLRLK_POSIX,
+        CLRLK_TYPE_MAX
+} clrlk_type;
+
+typedef enum {
+        CLRLK_BLOCKED = 1,
+        CLRLK_GRANTED,
+        CLRLK_ALL,
+        CLRLK_KIND_MAX
+} clrlk_kind;
+
+typedef enum {
+        KW_TYPE,
+        KW_KIND,
+        /*add new keywords here*/
+        KW_MAX
+} clrlk_opts;
+
+struct _clrlk_args;
+typedef struct _clrlk_args clrlk_args;
+
+struct _clrlk_args {
+        int type;
+        int kind;
+        char *opts;
+};
+
+int
+clrlk_get__kind (char *kind);
+int
+clrlk_get_type (char *type);
+int
+clrlk_get_lock_range (char *range_str, struct gf_flock *ulock,
+                      gf_boolean_t *chk_range);
+int
+clrlk_parse_args (const char* cmd, clrlk_args *args);
+
+int
+clrlk_clear_posixlk (xlator_t *this, pl_inode_t *pl_inode, clrlk_args *args,
+                     int *blkd, int *granted, int *op_errno);
+int
+clrlk_clear_inodelk (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
+                     clrlk_args *args, int *blkd, int *granted, int *op_errno);
+int
+clrlk_clear_entrylk (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom,
+                     clrlk_args *args, int *blkd, int *granted, int *op_errno);
+int
+clrlk_clear_lks_in_all_domains (xlator_t *this, pl_inode_t *pl_inode,
+                                clrlk_args *args, int *blkd, int *granted,
+                                int *op_errno);
+#endif /* __CLEAR_H__ */
diff --git a/xlators/features/locks/src/posix.c b/xlators/features/locks/src/posix.c
index 7ce4ec942be..bd30ca4937d 100644
--- a/xlators/features/locks/src/posix.c
+++ b/xlators/features/locks/src/posix.c
@@ -37,6 +37,7 @@
 #include "locks.h"
 #include "common.h"
 #include "statedump.h"
+#include "clear.h"
 
 #ifndef LLONG_MAX
 #define LLONG_MAX LONG_LONG_MAX /* compat with old gcc */
@@ -352,6 +353,114 @@ __delete_locks_of_owner (pl_inode_t *pl_inode,
         return;
 }
 
+
+int32_t
+pl_getxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                 int32_t op_ret, int32_t op_errno, dict_t *dict)
+{
+        STACK_UNWIND_STRICT (getxattr, frame, op_ret, op_errno, dict);
+        return 0;
+
+}
+
+int32_t
+pl_getxattr (call_frame_t *frame, xlator_t *this, loc_t *loc,
+             const char *name)
+{
+        int                     op_errno        = EINVAL;
+        int                     op_ret          = -1;
+        int32_t                 bcount          = 0;
+        int32_t                 gcount          = 0;
+        char                    key[PATH_MAX]   = {0, };
+        char                    *lk_summary     = NULL;
+        pl_inode_t              *pl_inode       = NULL;
+        dict_t                  *dict           = NULL;
+        clrlk_args              args           = {0,};
+
+        if (!name)
+                goto usual;
+
+        if (strncmp (name, GF_XATTR_CLRLK_CMD, strlen (GF_XATTR_CLRLK_CMD)))
+                goto usual;
+
+        if (clrlk_parse_args (name, &args)) {
+                op_errno = EINVAL;
+                goto out;
+        }
+
+        dict = dict_new ();
+        if (!dict) {
+                op_errno = ENOMEM;
+                goto out;
+        }
+
+        pl_inode = pl_inode_get (this, loc->inode);
+        if (!pl_inode) {
+                op_errno = ENOMEM;
+                goto out;
+        }
+
+        switch (args.type) {
+                case CLRLK_INODE:
+                case CLRLK_ENTRY:
+                        op_ret = clrlk_clear_lks_in_all_domains (this, pl_inode,
+                                                                 &args, &bcount,
+                                                                 &gcount,
+                                                                 &op_errno);
+                        if (op_ret)
+                                goto out;
+                        break;
+                case CLRLK_POSIX:
+                        op_ret = clrlk_clear_posixlk (this, pl_inode, &args,
+                                                      &bcount, &gcount,
+                                                      &op_errno);
+                        if (op_ret)
+                                goto out;
+                        break;
+                case CLRLK_TYPE_MAX:
+                        op_errno = EINVAL;
+                        goto out;
+        }
+
+        if (!gcount && !bcount) {
+                if (gf_asprintf (&lk_summary, "No locks cleared.") == -1) {
+                        op_errno = ENOMEM;
+                        goto out;
+                }
+        } else if (gf_asprintf (&lk_summary, "%s: %s blocked locks=%d "
+                                "granted locks=%d", this->name,
+                                (args.type == CLRLK_INODE)? "inode":
+                                (args.type == CLRLK_ENTRY)? "entry":
+                                (args.type == CLRLK_POSIX)? "posix": " ",
+                                bcount, gcount) == -1) {
+                op_errno = ENOMEM;
+                goto out;
+        }
+
+        strncpy (key, name, strlen (name));
+        if (dict_set_dynstr (dict, key, lk_summary)) {
+                op_errno = ENOMEM;
+                goto out;
+        }
+
+        op_ret = 0;
+out:
+        STACK_UNWIND_STRICT (getxattr, frame, op_ret, op_errno, dict);
+
+        if (args.opts)
+                GF_FREE (args.opts);
+        if (op_ret && lk_summary)
+                GF_FREE (lk_summary);
+        if (dict)
+                dict_unref (dict);
+        return 0;
+
+usual:
+        STACK_WIND (frame, pl_getxattr_cbk, FIRST_CHILD(this),
+                    FIRST_CHILD(this)->fops->getxattr, loc, name);
+        return 0;
+}
+
 int32_t
 pl_opendir_cbk (call_frame_t *frame,
                      void *cookie,
@@ -1980,8 +2089,8 @@ struct xlator_fops fops = {
         .fentrylk    = pl_fentrylk,
         .flush       = pl_flush,
         .opendir     = pl_opendir,
-
         .readdirp    = pl_readdirp,
+        .getxattr    = pl_getxattr,
 };
 
 struct xlator_dumpops dumpops = {