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ia64 warning fixes.
[fs/lustre-release.git] / lustre / llite / rw.c
index 805ac4b..3d62c58 100644 (file)
@@ -1,28 +1,44 @@
 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
  * vim:expandtab:shiftwidth=8:tabstop=8:
  *
- * Lustre Lite I/O page cache routines shared by different kernel revs
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
  *
- *   This file is part of Lustre, http://www.lustre.org.
+ * This program 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 version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
  *
- *   Lustre is free software; you can redistribute it and/or
- *   modify it under the terms of version 2 of the GNU General Public
- *   License as published by the Free Software Foundation.
+ * 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
  *
- *   Lustre 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.
+ * 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.
  *
- *   You should have received a copy of the GNU General Public License
- *   along with Lustre; if not, write to the Free Software
- *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * GPL HEADER END
  */
-#ifndef AUTOCONF_INCLUDED
-#include <linux/config.h>
-#endif
+/*
+ * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/llite/rw.c
+ *
+ * Lustre Lite I/O page cache routines shared by different kernel revs
+ */
+
+#include <linux/autoconf.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/string.h>
@@ -37,9 +53,6 @@
 #include <linux/fs.h>
 #include <linux/stat.h>
 #include <asm/uaccess.h>
-#ifdef HAVE_SEGMENT_H
-# include <asm/segment.h>
-#endif
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
@@ -48,6 +61,7 @@
 
 //#include <lustre_mdc.h>
 #include <lustre_lite.h>
+#include <obd_cksum.h>
 #include "llite_internal.h"
 #include <linux/lustre_compat25.h>
 
@@ -111,6 +125,47 @@ static int ll_brw(int cmd, struct inode *inode, struct obdo *oa,
         RETURN(rc);
 }
 
+int ll_file_punch(struct inode * inode, loff_t new_size, int srvlock)
+{
+        struct ll_inode_info *lli = ll_i2info(inode);
+        struct obd_info oinfo = { { { 0 } } };
+        struct obdo oa;
+        int rc;
+
+        ENTRY;
+        CDEBUG(D_INFO, "calling punch for "LPX64" (new size %Lu=%#Lx)\n",
+               lli->lli_smd->lsm_object_id, i_size_read(inode), i_size_read(inode));
+
+        oinfo.oi_md = lli->lli_smd;
+        oinfo.oi_policy.l_extent.start = new_size;
+        oinfo.oi_policy.l_extent.end = OBD_OBJECT_EOF;
+        oinfo.oi_oa = &oa;
+        oa.o_id = lli->lli_smd->lsm_object_id;
+        oa.o_gr = lli->lli_smd->lsm_object_gr;
+        oa.o_valid = OBD_MD_FLID | OBD_MD_FLGROUP;
+        if (srvlock) {
+                /* set OBD_MD_FLFLAGS in o_valid, only if we
+                 * set OBD_FL_TRUNCLOCK, otherwise ost_punch
+                 * and filter_setattr get confused, see the comment
+                 * in ost_punch */
+                oa.o_flags = OBD_FL_TRUNCLOCK;
+                oa.o_valid |= OBD_MD_FLFLAGS;
+        }
+        obdo_from_inode(&oa, inode, OBD_MD_FLTYPE | OBD_MD_FLMODE |
+                        OBD_MD_FLATIME | OBD_MD_FLMTIME | OBD_MD_FLCTIME |
+                        OBD_MD_FLFID | OBD_MD_FLGENER);
+
+        oinfo.oi_capa = ll_osscapa_get(inode, CAPA_OPC_OSS_TRUNC);
+        rc = obd_punch_rqset(ll_i2dtexp(inode), &oinfo, NULL);
+        ll_truncate_free_capa(oinfo.oi_capa);
+        if (rc)
+                CERROR("obd_truncate fails (%d) ino %lu\n", rc, inode->i_ino);
+        else
+                obdo_to_inode(inode, &oa, OBD_MD_FLSIZE | OBD_MD_FLBLOCKS |
+                              OBD_MD_FLATIME | OBD_MD_FLMTIME | OBD_MD_FLCTIME);
+        RETURN(rc);
+}
+
 /* this isn't where truncate starts.   roughly:
  * sys_truncate->ll_setattr_raw->vmtruncate->ll_truncate. setattr_raw grabs
  * DLM lock on [size, EOF], i_mutex, ->lli_size_sem, and WRITE_I_ALLOC_SEM to
@@ -120,10 +175,8 @@ static int ll_brw(int cmd, struct inode *inode, struct obdo *oa,
 void ll_truncate(struct inode *inode)
 {
         struct ll_inode_info *lli = ll_i2info(inode);
-        struct obd_info oinfo = { { { 0 } } };
-        struct ost_lvb lvb;
-        struct obdo oa;
-        int rc;
+        int srvlock = !!(lli->lli_flags & LLIF_SRVLOCK);
+        loff_t new_size;
         ENTRY;
         CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p) to %Lu=%#Lx\n",inode->i_ino,
                inode->i_generation, inode, i_size_read(inode),
@@ -143,22 +196,27 @@ void ll_truncate(struct inode *inode)
 
         LASSERT(atomic_read(&lli->lli_size_sem.count) <= 0);
 
-        /* XXX I'm pretty sure this is a hack to paper over a more fundamental
-         * race condition. */
-        lov_stripe_lock(lli->lli_smd);
-        inode_init_lvb(inode, &lvb);
-        rc = obd_merge_lvb(ll_i2dtexp(inode), lli->lli_smd, &lvb, 0);
-        if (lvb.lvb_size == i_size_read(inode) && rc == 0) {
-                CDEBUG(D_VFSTRACE, "skipping punch for obj "LPX64", %Lu=%#Lx\n",
-                       lli->lli_smd->lsm_object_id, i_size_read(inode),
-                       i_size_read(inode));
+        if (!srvlock) {
+                struct ost_lvb lvb;
+                int rc;
+
+                /* XXX I'm pretty sure this is a hack to paper
+                 * over a more fundamental race condition. */
+                lov_stripe_lock(lli->lli_smd);
+                inode_init_lvb(inode, &lvb);
+                rc = obd_merge_lvb(ll_i2dtexp(inode), lli->lli_smd, &lvb, 0);
+                if (lvb.lvb_size == i_size_read(inode) && rc == 0) {
+                        CDEBUG(D_VFSTRACE, "skipping punch for obj "LPX64
+                               ",%Lu=%#Lx\n", lli->lli_smd->lsm_object_id,
+                               i_size_read(inode), i_size_read(inode));
+                        lov_stripe_unlock(lli->lli_smd);
+                        GOTO(out_unlock, 0);
+                }
+                obd_adjust_kms(ll_i2dtexp(inode), lli->lli_smd,
+                               i_size_read(inode), 1);
                 lov_stripe_unlock(lli->lli_smd);
-                GOTO(out_unlock, 0);
         }
 
-        obd_adjust_kms(ll_i2dtexp(inode), lli->lli_smd, i_size_read(inode), 1);
-        lov_stripe_unlock(lli->lli_smd);
-
         if (unlikely((ll_i2sbi(inode)->ll_flags & LL_SBI_CHECKSUM) &&
                      (i_size_read(inode) & ~CFS_PAGE_MASK))) {
                 /* If the truncate leaves behind a partial page, update its
@@ -171,38 +229,24 @@ void ll_truncate(struct inode *inode)
                         if (llap != NULL) {
                                 char *kaddr = kmap_atomic(page, KM_USER0);
                                 llap->llap_checksum =
-                                        crc32_le(0, kaddr, CFS_PAGE_SIZE);
+                                        init_checksum(OSC_DEFAULT_CKSUM);
+                                llap->llap_checksum =
+                                        compute_checksum(llap->llap_checksum,
+                                                         kaddr, CFS_PAGE_SIZE,
+                                                         OSC_DEFAULT_CKSUM);
                                 kunmap_atomic(kaddr, KM_USER0);
                         }
                         page_cache_release(page);
                 }
         }
 
-        CDEBUG(D_INFO, "calling punch for "LPX64" (new size %Lu=%#Lx)\n",
-               lli->lli_smd->lsm_object_id, i_size_read(inode), i_size_read(inode));
-
-        oinfo.oi_md = lli->lli_smd;
-        oinfo.oi_policy.l_extent.start = i_size_read(inode);
-        oinfo.oi_policy.l_extent.end = OBD_OBJECT_EOF;
-        oinfo.oi_oa = &oa;
-        oa.o_id = lli->lli_smd->lsm_object_id;
-        oa.o_gr = lli->lli_smd->lsm_object_gr;
-        oa.o_valid = OBD_MD_FLID | OBD_MD_FLGROUP;
-
-        obdo_from_inode(&oa, inode, OBD_MD_FLTYPE | OBD_MD_FLMODE |
-                        OBD_MD_FLATIME | OBD_MD_FLMTIME | OBD_MD_FLCTIME |
-                        OBD_MD_FLFID | OBD_MD_FLGENER);
-
+        new_size = i_size_read(inode);
         ll_inode_size_unlock(inode, 0);
-
-        oinfo.oi_capa = ll_osscapa_get(inode, CAPA_OPC_OSS_TRUNC);
-        rc = obd_punch_rqset(ll_i2dtexp(inode), &oinfo, NULL);
-        ll_truncate_free_capa(oinfo.oi_capa);
-        if (rc)
-                CERROR("obd_truncate fails (%d) ino %lu\n", rc, inode->i_ino);
+        if (!srvlock)
+                ll_file_punch(inode, new_size, 0);
         else
-                obdo_to_inode(inode, &oa, OBD_MD_FLSIZE | OBD_MD_FLBLOCKS |
-                              OBD_MD_FLATIME | OBD_MD_FLMTIME | OBD_MD_FLCTIME);
+                ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_LOCKLESS_TRUNC, 1);
+
         EXIT;
         return;
 
@@ -236,7 +280,7 @@ int ll_prepare_write(struct file *file, struct page *page, unsigned from,
         oa.o_mode = inode->i_mode;
         oa.o_id = lsm->lsm_object_id;
         oa.o_gr = lsm->lsm_object_gr;
-        oa.o_valid = OBD_MD_FLID | OBD_MD_FLMODE | 
+        oa.o_valid = OBD_MD_FLID | OBD_MD_FLMODE |
                      OBD_MD_FLTYPE | OBD_MD_FLGROUP;
         obdo_from_inode(&oa, inode, OBD_MD_FLFID | OBD_MD_FLGENER);
 
@@ -291,6 +335,14 @@ int ll_prepare_write(struct file *file, struct page *page, unsigned from,
         return rc;
 }
 
+/**
+ * make page ready for ASYNC write
+ * \param data - pointer to llap cookie
+ * \param cmd - is OBD_BRW_* macroses
+ *
+ * \retval 0 is page successfully prepared to send
+ * \retval -EAGAIN is page not need to send
+ */
 static int ll_ap_make_ready(void *data, int cmd)
 {
         struct ll_async_page *llap;
@@ -300,14 +352,13 @@ static int ll_ap_make_ready(void *data, int cmd)
         llap = LLAP_FROM_COOKIE(data);
         page = llap->llap_page;
 
-        LASSERTF(!(cmd & OBD_BRW_READ), "cmd %x page %p ino %lu index %lu\n", cmd, page,
-                 page->mapping->host->i_ino, page->index);
-
         /* we're trying to write, but the page is locked.. come back later */
         if (TryLockPage(page))
                 RETURN(-EAGAIN);
 
-        LASSERT(!PageWriteback(page));
+        LASSERTF(!(cmd & OBD_BRW_READ) || !PageWriteback(page),
+                "cmd %x page %p ino %lu index %lu fl %lx\n", cmd, page,
+                 page->mapping->host->i_ino, page->index, page->flags);
 
         /* if we left PageDirty we might get another writepage call
          * in the future.  list walkers are bright enough
@@ -318,7 +369,10 @@ static int ll_ap_make_ready(void *data, int cmd)
          * cli lock */
         LASSERTF(!PageWriteback(page),"cmd %x page %p ino %lu index %lu\n", cmd, page,
                  page->mapping->host->i_ino, page->index);
-        clear_page_dirty_for_io(page);
+        if(!clear_page_dirty_for_io(page)) {
+               unlock_page(page);
+               RETURN(-EAGAIN);
+       }
 
         /* This actually clears the dirty bit in the radix tree.*/
         set_page_writeback(page);
@@ -455,50 +509,36 @@ struct ll_async_page *llap_cast_private(struct page *page)
         return llap;
 }
 
-/* Try to shrink the page cache for the @sbi filesystem by 1/@shrink_fraction.
+/* Try to reap @target pages in the specific @cpu's async page list.
  *
  * There is an llap attached onto every page in lustre, linked off @sbi.
  * We add an llap to the list so we don't lose our place during list walking.
  * If llaps in the list are being moved they will only move to the end
  * of the LRU, and we aren't terribly interested in those pages here (we
- * start at the beginning of the list where the least-used llaps are.
- */
-int llap_shrink_cache(struct ll_sb_info *sbi, int shrink_fraction)
+ * start at the beginning of the list where the least-used llaps are. */
+static inline int llap_shrink_cache_internal(struct ll_sb_info *sbi, 
+        int cpu, int target)
 {
         struct ll_async_page *llap, dummy_llap = { .llap_magic = 0xd11ad11a };
-        unsigned long total, want, count = 0;
-
-        total = sbi->ll_async_page_count;
-
-        /* There can be a large number of llaps (600k or more in a large
-         * memory machine) so the VM 1/6 shrink ratio is likely too much.
-         * Since we are freeing pages also, we don't necessarily want to
-         * shrink so much.  Limit to 40MB of pages + llaps per call. */
-        if (shrink_fraction == 0)
-                want = sbi->ll_async_page_count - sbi->ll_async_page_max + 32;
-        else
-                want = (total + shrink_fraction - 1) / shrink_fraction;
-
-        if (want > 40 << (20 - CFS_PAGE_SHIFT))
-                want = 40 << (20 - CFS_PAGE_SHIFT);
-
-        CDEBUG(D_CACHE, "shrinking %lu of %lu pages (1/%d)\n",
-               want, total, shrink_fraction);
-
-        spin_lock(&sbi->ll_lock);
-        list_add(&dummy_llap.llap_pglist_item, &sbi->ll_pglist);
-
-        while (--total >= 0 && count < want) {
+        struct ll_pglist_data *pd;
+        struct list_head *head;
+        int count = 0;
+
+        pd = ll_pglist_cpu_lock(sbi, cpu);
+        head = &pd->llpd_list;
+        list_add(&dummy_llap.llap_pglist_item, head);
+        while (count < target) {
                 struct page *page;
                 int keep;
 
                 if (unlikely(need_resched())) {
-                        spin_unlock(&sbi->ll_lock);
+                        ll_pglist_cpu_unlock(sbi, cpu);
                         cond_resched();
-                        spin_lock(&sbi->ll_lock);
+                        ll_pglist_cpu_lock(sbi, cpu);
                 }
 
-                llap = llite_pglist_next_llap(sbi,&dummy_llap.llap_pglist_item);
+                llap = llite_pglist_next_llap(head, 
+                        &dummy_llap.llap_pglist_item);
                 list_del_init(&dummy_llap.llap_pglist_item);
                 if (llap == NULL)
                         break;
@@ -534,7 +574,7 @@ int llap_shrink_cache(struct ll_sb_info *sbi, int shrink_fraction)
                 }
 
                 page_cache_get(page);
-                spin_unlock(&sbi->ll_lock);
+                ll_pglist_cpu_unlock(sbi, cpu);
 
                 if (page->mapping != NULL) {
                         ll_teardown_mmaps(page->mapping,
@@ -556,24 +596,158 @@ int llap_shrink_cache(struct ll_sb_info *sbi, int shrink_fraction)
                 unlock_page(page);
                 page_cache_release(page);
 
-                spin_lock(&sbi->ll_lock);
+                ll_pglist_cpu_lock(sbi, cpu);
         }
         list_del(&dummy_llap.llap_pglist_item);
-        spin_unlock(&sbi->ll_lock);
+        ll_pglist_cpu_unlock(sbi, cpu);
+
+        CDEBUG(D_CACHE, "shrank %d, expected %d however. \n", count, target);
+        return count;
+}
+
+
+/* Try to shrink the page cache for the @sbi filesystem by 1/@shrink_fraction.
+ *
+ * At first, this code calculates total pages wanted by @shrink_fraction, then
+ * it deduces how many pages should be reaped from each cpu in proportion as 
+ * their own # of page count(llpd_count).
+ */
+int llap_shrink_cache(struct ll_sb_info *sbi, int shrink_fraction)
+{
+        unsigned long total, want, percpu_want, count = 0;
+        int cpu, nr_cpus;
+
+        total = lcounter_read(&sbi->ll_async_page_count);
+        if (total == 0)
+                return 0;
+
+#ifdef HAVE_SHRINKER_CACHE
+        want = shrink_fraction;
+        if (want == 0)
+                return total;
+#else
+        /* There can be a large number of llaps (600k or more in a large
+         * memory machine) so the VM 1/6 shrink ratio is likely too much.
+         * Since we are freeing pages also, we don't necessarily want to
+         * shrink so much.  Limit to 40MB of pages + llaps per call. */
+        if (shrink_fraction <= 0)
+                want = total - sbi->ll_async_page_max + 32*num_online_cpus();
+        else
+                want = (total + shrink_fraction - 1) / shrink_fraction;
+#endif
+
+        if (want > 40 << (20 - CFS_PAGE_SHIFT))
+                want = 40 << (20 - CFS_PAGE_SHIFT);
+
+        CDEBUG(D_CACHE, "shrinking %lu of %lu pages (1/%d)\n",
+               want, total, shrink_fraction);
+
+        nr_cpus = num_possible_cpus();
+        cpu = sbi->ll_async_page_clock_hand;
+        /* we at most do one round */
+        do {
+                int c;
+
+                cpu = (cpu + 1) % nr_cpus;
+                c = LL_PGLIST_DATA_CPU(sbi, cpu)->llpd_count;
+                if (!cpu_online(cpu))
+                        percpu_want = c;
+                else
+                        percpu_want = want / ((total / (c + 1)) + 1);
+                if (percpu_want == 0)
+                        continue;
+
+                count += llap_shrink_cache_internal(sbi, cpu, percpu_want);
+                if (count >= want)
+                        sbi->ll_async_page_clock_hand = cpu;
+        } while (cpu != sbi->ll_async_page_clock_hand);
 
         CDEBUG(D_CACHE, "shrank %lu/%lu and left %lu unscanned\n",
                count, want, total);
 
+#ifdef HAVE_SHRINKER_CACHE
+        return lcounter_read(&sbi->ll_async_page_count);
+#else
         return count;
+#endif
 }
 
-struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
+/* Rebalance the async page queue len for each cpu. We hope that the cpu
+ * which do much IO job has a relative longer queue len.
+ * This function should be called with preempt disabled.
+ */
+static inline int llap_async_cache_rebalance(struct ll_sb_info *sbi)
+{
+        unsigned long sample = 0, *cpu_sample, bias, slice;
+        struct ll_pglist_data *pd;
+        cpumask_t mask;
+        int cpu, surplus;
+        int w1 = 7, w2 = 3, base = (w1 + w2); /* weight value */
+        atomic_t *pcnt;
+
+        if (!spin_trylock(&sbi->ll_async_page_reblnc_lock)) {
+                /* someone else is doing the job */
+                return 1;
+        }
+
+        pcnt = &LL_PGLIST_DATA(sbi)->llpd_sample_count;
+        if (!atomic_read(pcnt)) {
+                /* rare case, somebody else has gotten this job done */
+                spin_unlock(&sbi->ll_async_page_reblnc_lock);
+                return 1;
+        }
+
+        sbi->ll_async_page_reblnc_count++;
+        cpu_sample = sbi->ll_async_page_sample;
+        memset(cpu_sample, 0, num_possible_cpus() * sizeof(unsigned long));
+        for_each_online_cpu(cpu) {
+                pcnt = &LL_PGLIST_DATA_CPU(sbi, cpu)->llpd_sample_count;
+                cpu_sample[cpu] = atomic_read(pcnt);
+                atomic_set(pcnt, 0);
+                sample += cpu_sample[cpu];
+        }
+
+        cpus_clear(mask);
+        surplus = sbi->ll_async_page_max;
+        slice = surplus / sample + 1;
+        sample /= num_online_cpus();
+        bias = sample >> 4;
+        for_each_online_cpu(cpu) {
+                pd = LL_PGLIST_DATA_CPU(sbi, cpu);
+                if (labs((long int)sample - cpu_sample[cpu]) > bias) {
+                        unsigned long budget = pd->llpd_budget;
+                        /* weighted original queue length and expected queue
+                         * length to avoid thrashing. */
+                        pd->llpd_budget = (budget * w1) / base +
+                                        (slice * cpu_sample[cpu]) * w2 / base;
+                        cpu_set(cpu, mask);
+                }
+                surplus -= pd->llpd_budget;
+        }
+        surplus /= cpus_weight(mask) ?: 1;
+        for_each_cpu_mask(cpu, mask)
+                LL_PGLIST_DATA_CPU(sbi, cpu)->llpd_budget += surplus;
+        spin_unlock(&sbi->ll_async_page_reblnc_lock);
+
+        /* TODO: do we really need to call llap_shrink_cache_internal 
+         * for every cpus with its page_count greater than budget?
+         * for_each_cpu_mask(cpu, mask) 
+         *      ll_shrink_cache_internal(...) 
+         */
+
+        return 0;
+}
+
+static struct ll_async_page *llap_from_page_with_lockh(struct page *page,
+                                                       unsigned origin,
+                                                       struct lustre_handle *lockh)
 {
         struct ll_async_page *llap;
         struct obd_export *exp;
         struct inode *inode = page->mapping->host;
         struct ll_sb_info *sbi;
-        int rc;
+        struct ll_pglist_data *pd;
+        int rc, cpu, target;
         ENTRY;
 
         if (!inode) {
@@ -596,11 +770,30 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
                 /* move to end of LRU list, except when page is just about to
                  * die */
                 if (origin != LLAP_ORIGIN_REMOVEPAGE) {
-                        spin_lock(&sbi->ll_lock);
-                        sbi->ll_pglist_gen++;
-                        list_del_init(&llap->llap_pglist_item);
-                        list_add_tail(&llap->llap_pglist_item, &sbi->ll_pglist);
-                        spin_unlock(&sbi->ll_lock);
+                        int old_cpu = llap->llap_pglist_cpu;
+                        struct ll_pglist_data *old_pd;
+
+                        pd = ll_pglist_double_lock(sbi, old_cpu, &old_pd);
+                        pd->llpd_hit++;
+                        while (old_cpu != llap->llap_pglist_cpu) {
+                                /* rarely case, someone else is touching this
+                                 * page too. */
+                                ll_pglist_double_unlock(sbi, old_cpu);
+                                old_cpu = llap->llap_pglist_cpu;
+                                pd=ll_pglist_double_lock(sbi, old_cpu, &old_pd);
+                        }
+
+                        list_move(&llap->llap_pglist_item,
+                                  &pd->llpd_list);
+                        old_pd->llpd_gen++;
+                        if (pd->llpd_cpu != old_cpu) {
+                                pd->llpd_count++;
+                                old_pd->llpd_count--;
+                                old_pd->llpd_gen++;
+                                llap->llap_pglist_cpu = pd->llpd_cpu;
+                                pd->llpd_cross++;
+                        }
+                        ll_pglist_double_unlock(sbi, old_cpu);
                 }
                 GOTO(out, llap);
         }
@@ -610,8 +803,28 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
                 RETURN(ERR_PTR(-EINVAL));
 
         /* limit the number of lustre-cached pages */
-        if (sbi->ll_async_page_count >= sbi->ll_async_page_max)
-                llap_shrink_cache(sbi, 0);
+        cpu = get_cpu();
+        pd = LL_PGLIST_DATA(sbi);
+        target = pd->llpd_count - pd->llpd_budget;
+        if (target > 0) {
+                rc = 0;
+                atomic_inc(&pd->llpd_sample_count);
+                if (atomic_read(&pd->llpd_sample_count) > 
+                    sbi->ll_async_page_sample_max) {
+                        pd->llpd_reblnc_count++;
+                        rc = llap_async_cache_rebalance(sbi);
+                        if (rc == 0)
+                                target = pd->llpd_count - pd->llpd_budget;
+                }
+                /* if rc equals 1, it means other cpu is doing the rebalance
+                 * job, and our budget # would be modified when we read it. 
+                 * Furthermore, it is much likely being increased because
+                 * we have already reached the rebalance threshold. In this
+                 * case, we skip to shrink cache here. */
+                if ((rc == 0) && target > 0)
+                        llap_shrink_cache_internal(sbi, cpu, target + 32);
+        }
+        put_cpu();
 
         OBD_SLAB_ALLOC(llap, ll_async_page_slab, CFS_ALLOC_STD,
                        ll_async_page_slab_size);
@@ -620,9 +833,14 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
         llap->llap_magic = LLAP_MAGIC;
         llap->llap_cookie = (void *)llap + size_round(sizeof(*llap));
 
+        /* XXX: for bug 11270 - check for lockless origin here! */
+        if (origin == LLAP_ORIGIN_LOCKLESS_IO)
+                llap->llap_nocache = 1;
+
         rc = obd_prep_async_page(exp, ll_i2info(inode)->lli_smd, NULL, page,
                                  (obd_off)page->index << CFS_PAGE_SHIFT,
-                                 &ll_async_page_ops, llap, &llap->llap_cookie);
+                                 &ll_async_page_ops, llap, &llap->llap_cookie,
+                                 llap->llap_nocache, lockh);
         if (rc) {
                 OBD_SLAB_FREE(llap, ll_async_page_slab,
                               ll_async_page_slab_size);
@@ -634,21 +852,28 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
         /* also zeroing the PRIVBITS low order bitflags */
         __set_page_ll_data(page, llap);
         llap->llap_page = page;
-        spin_lock(&sbi->ll_lock);
-        sbi->ll_pglist_gen++;
-        sbi->ll_async_page_count++;
-        list_add_tail(&llap->llap_pglist_item, &sbi->ll_pglist);
+
+        lcounter_inc(&sbi->ll_async_page_count);
+        pd = ll_pglist_lock(sbi);
+        list_add_tail(&llap->llap_pglist_item, &pd->llpd_list);
         INIT_LIST_HEAD(&llap->llap_pending_write);
-        spin_unlock(&sbi->ll_lock);
+        pd->llpd_count++;
+        pd->llpd_gen++;
+        pd->llpd_miss++;
+        llap->llap_pglist_cpu = pd->llpd_cpu;
+        ll_pglist_unlock(sbi);
 
  out:
         if (unlikely(sbi->ll_flags & LL_SBI_CHECKSUM)) {
-                __u32 csum = 0;
+                __u32 csum;
                 char *kaddr = kmap_atomic(page, KM_USER0);
-                csum = crc32_le(csum, kaddr, CFS_PAGE_SIZE);
+                csum = init_checksum(OSC_DEFAULT_CKSUM);
+                csum = compute_checksum(csum, kaddr, CFS_PAGE_SIZE,
+                                        OSC_DEFAULT_CKSUM);
                 kunmap_atomic(kaddr, KM_USER0);
                 if (origin == LLAP_ORIGIN_READAHEAD ||
-                    origin == LLAP_ORIGIN_READPAGE) {
+                    origin == LLAP_ORIGIN_READPAGE ||
+                    origin == LLAP_ORIGIN_LOCKLESS_IO) {
                         llap->llap_checksum = 0;
                 } else if (origin == LLAP_ORIGIN_COMMIT_WRITE ||
                            llap->llap_checksum == 0) {
@@ -669,6 +894,12 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
         RETURN(llap);
 }
 
+struct ll_async_page *llap_from_page(struct page *page,
+                                     unsigned origin)
+{
+        return llap_from_page_with_lockh(page, origin, NULL);
+}
+
 static int queue_or_sync_write(struct obd_export *exp, struct inode *inode,
                                struct ll_async_page *llap,
                                unsigned to, obd_flag async_flags)
@@ -692,7 +923,7 @@ static int queue_or_sync_write(struct obd_export *exp, struct inode *inode,
         llap->llap_write_queued = 0;
         /* Do not pass llap here as it is sync write. */
         llap_write_pending(inode, NULL);
-        
+
         rc = oig_init(&oig);
         if (rc)
                 GOTO(out, rc);
@@ -715,10 +946,12 @@ static int queue_or_sync_write(struct obd_export *exp, struct inode *inode,
         /* compare the checksum once before the page leaves llite */
         if (unlikely((sbi->ll_flags & LL_SBI_CHECKSUM) &&
                      llap->llap_checksum != 0)) {
-                __u32 csum = 0;
+                __u32 csum;
                 struct page *page = llap->llap_page;
                 char *kaddr = kmap_atomic(page, KM_USER0);
-                csum = crc32_le(csum, kaddr, CFS_PAGE_SIZE);
+                csum = init_checksum(OSC_DEFAULT_CKSUM);
+                csum = compute_checksum(csum, kaddr, CFS_PAGE_SIZE,
+                                        OSC_DEFAULT_CKSUM);
                 kunmap_atomic(kaddr, KM_USER0);
                 if (llap->llap_checksum == csum) {
                         CDEBUG(D_PAGE, "page %p cksum %x confirmed\n",
@@ -744,9 +977,8 @@ static int queue_or_sync_write(struct obd_export *exp, struct inode *inode,
 
         if (!rc && async_flags & ASYNC_READY) {
                 unlock_page(llap->llap_page);
-                if (PageWriteback(llap->llap_page)) {
+                if (PageWriteback(llap->llap_page))
                         end_page_writeback(llap->llap_page);
-                }
         }
 
         if (rc == 0 && llap_write_complete(inode, llap))
@@ -768,12 +1000,14 @@ out:
 int ll_commit_write(struct file *file, struct page *page, unsigned from,
                     unsigned to)
 {
+        struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
         struct inode *inode = page->mapping->host;
         struct ll_inode_info *lli = ll_i2info(inode);
         struct lov_stripe_md *lsm = lli->lli_smd;
         struct obd_export *exp;
         struct ll_async_page *llap;
         loff_t size;
+        struct lustre_handle *lockh = NULL;
         int rc = 0;
         ENTRY;
 
@@ -784,7 +1018,10 @@ int ll_commit_write(struct file *file, struct page *page, unsigned from,
         CDEBUG(D_INODE, "inode %p is writing page %p from %d to %d at %lu\n",
                inode, page, from, to, page->index);
 
-        llap = llap_from_page(page, LLAP_ORIGIN_COMMIT_WRITE);
+        if (fd->fd_flags & LL_FILE_GROUP_LOCKED)
+                lockh = &fd->fd_cwlockh;
+
+        llap = llap_from_page_with_lockh(page, LLAP_ORIGIN_COMMIT_WRITE, lockh);
         if (IS_ERR(llap))
                 RETURN(PTR_ERR(llap));
 
@@ -850,28 +1087,40 @@ out:
         RETURN(rc);
 }
 
+static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which);
+
+/* WARNING: This algorithm is used to reduce the contention on 
+ * sbi->ll_lock. It should work well if the ra_max_pages is much 
+ * greater than the single file's read-ahead window.
+ *
+ * TODO: There may exist a `global sync problem' in this implementation. 
+ * Considering the global ra window is 100M, and each file's ra window is 10M,
+ * there are over 10 files trying to get its ra budget and reach 
+ * ll_ra_count_get at the exactly same time. All of them will get a zero ra
+ * window, although the global window is 100M. -jay
+ */
 static unsigned long ll_ra_count_get(struct ll_sb_info *sbi, unsigned long len)
 {
         struct ll_ra_info *ra = &sbi->ll_ra_info;
         unsigned long ret;
         ENTRY;
 
-        spin_lock(&sbi->ll_lock);
-        ret = min(ra->ra_max_pages - ra->ra_cur_pages, len);
-        ra->ra_cur_pages += ret;
-        spin_unlock(&sbi->ll_lock);
+        ret = min(ra->ra_max_pages - atomic_read(&ra->ra_cur_pages), len);
+        if ((int)ret < 0)
+                GOTO(out, ret = 0);
 
+        if (atomic_add_return(ret, &ra->ra_cur_pages) > ra->ra_max_pages) {
+                atomic_sub(ret, &ra->ra_cur_pages);
+                ret = 0;
+        }
+out:
         RETURN(ret);
 }
 
 static void ll_ra_count_put(struct ll_sb_info *sbi, unsigned long len)
 {
         struct ll_ra_info *ra = &sbi->ll_ra_info;
-        spin_lock(&sbi->ll_lock);
-        LASSERTF(ra->ra_cur_pages >= len, "r_c_p %lu len %lu\n",
-                 ra->ra_cur_pages, len);
-        ra->ra_cur_pages -= len;
-        spin_unlock(&sbi->ll_lock);
+        atomic_sub(len, &ra->ra_cur_pages);
 }
 
 /* called for each page in a completed rpc.*/
@@ -886,7 +1135,7 @@ int ll_ap_completion(void *data, int cmd, struct obdo *oa, int rc)
         page = llap->llap_page;
         LASSERT(PageLocked(page));
         LASSERT(CheckWriteback(page,cmd));
-        
+
         LL_CDEBUG_PAGE(D_PAGE, page, "completing cmd %d with %d\n", cmd, rc);
 
         if (cmd & OBD_BRW_READ && llap->llap_defer_uptodate)
@@ -911,48 +1160,39 @@ int ll_ap_completion(void *data, int cmd, struct obdo *oa, int rc)
                         set_bit(AS_EIO, &page->mapping->flags);
         }
 
+        /* be carefull about clear WB.
+         * if WB will cleared after page lock is released - paralel IO can be
+         * started before ap_make_ready is finished - so we will be have page
+         * with PG_Writeback set from ->writepage() and completed READ which
+         * clear this flag */
+        if ((cmd & OBD_BRW_WRITE) && PageWriteback(page))
+                end_page_writeback(page);
+
         unlock_page(page);
 
         if (cmd & OBD_BRW_WRITE) {
                 /* Only rc == 0, write succeed, then this page could be deleted
-                 * from the pending_writing list 
+                 * from the pending_writing list
                  */
                 if (rc == 0 && llap_write_complete(page->mapping->host, llap))
                         ll_queue_done_writing(page->mapping->host, 0);
         }
 
-        if (PageWriteback(page)) {
-                end_page_writeback(page);
-        }
         page_cache_release(page);
 
         RETURN(ret);
 }
 
-/* the kernel calls us here when a page is unhashed from the page cache.
- * the page will be locked and the kernel is holding a spinlock, so
- * we need to be careful.  we're just tearing down our book-keeping
- * here. */
-void ll_removepage(struct page *page)
+static void __ll_put_llap(struct page *page)
 {
         struct inode *inode = page->mapping->host;
         struct obd_export *exp;
         struct ll_async_page *llap;
         struct ll_sb_info *sbi = ll_i2sbi(inode);
-        int rc;
+        struct ll_pglist_data *pd;
+        int rc, cpu;
         ENTRY;
 
-        LASSERT(!in_interrupt());
-
-        /* sync pages or failed read pages can leave pages in the page
-         * cache that don't have our data associated with them anymore */
-        if (page_private(page) == 0) {
-                EXIT;
-                return;
-        }
-
-        LL_CDEBUG_PAGE(D_PAGE, page, "being evicted\n");
-
         exp = ll_i2dtexp(inode);
         if (exp == NULL) {
                 CERROR("page %p ind %lu gave null export\n", page, page->index);
@@ -980,38 +1220,41 @@ void ll_removepage(struct page *page)
          * is providing exclusivity to memory pressure/truncate/writeback..*/
         __clear_page_ll_data(page);
 
-        spin_lock(&sbi->ll_lock);
+        lcounter_dec(&sbi->ll_async_page_count);
+        cpu = llap->llap_pglist_cpu;
+        pd = ll_pglist_cpu_lock(sbi, cpu);
+        pd->llpd_gen++;
+        pd->llpd_count--;
         if (!list_empty(&llap->llap_pglist_item))
                 list_del_init(&llap->llap_pglist_item);
-        sbi->ll_pglist_gen++;
-        sbi->ll_async_page_count--;
-        spin_unlock(&sbi->ll_lock);
+        ll_pglist_cpu_unlock(sbi, cpu);
         OBD_SLAB_FREE(llap, ll_async_page_slab, ll_async_page_slab_size);
         EXIT;
 }
 
-static int ll_page_matches(struct page *page, int fd_flags)
+/* the kernel calls us here when a page is unhashed from the page cache.
+ * the page will be locked and the kernel is holding a spinlock, so
+ * we need to be careful.  we're just tearing down our book-keeping
+ * here. */
+void ll_removepage(struct page *page)
 {
-        struct lustre_handle match_lockh = {0};
-        struct inode *inode = page->mapping->host;
-        ldlm_policy_data_t page_extent;
-        int flags, matches;
+        struct ll_async_page *llap = llap_cast_private(page);
         ENTRY;
 
-        if (unlikely(fd_flags & LL_FILE_GROUP_LOCKED))
-                RETURN(1);
-
-        page_extent.l_extent.start = (__u64)page->index << CFS_PAGE_SHIFT;
-        page_extent.l_extent.end =
-                page_extent.l_extent.start + CFS_PAGE_SIZE - 1;
-        flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED;
-        if (!(fd_flags & LL_FILE_READAHEAD))
-                flags |= LDLM_FL_CBPENDING;
-        matches = obd_match(ll_i2sbi(inode)->ll_dt_exp,
-                            ll_i2info(inode)->lli_smd, LDLM_EXTENT,
-                            &page_extent, LCK_PR | LCK_PW, &flags, inode,
-                            &match_lockh);
-        RETURN(matches);
+        LASSERT(!in_interrupt());
+
+        /* sync pages or failed read pages can leave pages in the page
+         * cache that don't have our data associated with them anymore */
+        if (page_private(page) == 0) {
+                EXIT;
+                return;
+        }
+
+        LASSERT(!llap->llap_lockless_io_page);
+        LASSERT(!llap->llap_nocache);
+        LL_CDEBUG_PAGE(D_PAGE, page, "being evicted\n");
+        __ll_put_llap(page);
+        EXIT;
 }
 
 static int ll_issue_page_read(struct obd_export *exp,
@@ -1035,20 +1278,16 @@ static int ll_issue_page_read(struct obd_export *exp,
         RETURN(rc);
 }
 
-static void ll_ra_stats_inc_unlocked(struct ll_ra_info *ra, enum ra_stat which)
+static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which)
 {
         LASSERTF(which >= 0 && which < _NR_RA_STAT, "which: %u\n", which);
-        ra->ra_stats[which]++;
+        lprocfs_counter_incr(sbi->ll_ra_stats, which);
 }
 
 static void ll_ra_stats_inc(struct address_space *mapping, enum ra_stat which)
 {
         struct ll_sb_info *sbi = ll_i2sbi(mapping->host);
-        struct ll_ra_info *ra = &ll_i2sbi(mapping->host)->ll_ra_info;
-
-        spin_lock(&sbi->ll_lock);
-        ll_ra_stats_inc_unlocked(ra, which);
-        spin_unlock(&sbi->ll_lock);
+        ll_ra_stats_inc_sbi(sbi, which);
 }
 
 void ll_ra_accounting(struct ll_async_page *llap, struct address_space *mapping)
@@ -1142,14 +1381,14 @@ struct ll_ra_read *ll_ra_read_get(struct file *f)
         return bead;
 }
 
-static int ll_read_ahead_page(struct obd_export *exp, struct obd_io_group *oig, 
+static int ll_read_ahead_page(struct obd_export *exp, struct obd_io_group *oig,
                               int index, struct address_space *mapping)
 {
         struct ll_async_page *llap;
         struct page *page;
         unsigned int gfp_mask = 0;
-        int rc = 0;       
+        int rc = 0;
+
         gfp_mask = GFP_HIGHUSER & ~__GFP_WAIT;
 #ifdef __GFP_NOWARN
         gfp_mask |= __GFP_NOWARN;
@@ -1187,7 +1426,7 @@ static int ll_read_ahead_page(struct obd_export *exp, struct obd_io_group *oig,
         /* skip completed pages */
         if (Page_Uptodate(page))
                 GOTO(unlock_page, rc = 0);     
-        
+
         /* bail out when we hit the end of the lock. */
         rc = ll_issue_page_read(exp, llap, oig, 1);
         if (rc == 0) {
@@ -1202,21 +1441,21 @@ unlock_page:
         return rc;
 }
 
-/* ra_io_arg will be filled in the beginning of ll_readahead with 
- * ras_lock, then the following ll_read_ahead_pages will read RA 
+/* ra_io_arg will be filled in the beginning of ll_readahead with
+ * ras_lock, then the following ll_read_ahead_pages will read RA
  * pages according to this arg, all the items in this structure are
  * counted by page index.
  */
 struct ra_io_arg {
         unsigned long ria_start;  /* start offset of read-ahead*/
-        unsigned long ria_end;    /* end offset of read-ahead*/ 
+        unsigned long ria_end;    /* end offset of read-ahead*/
         /* If stride read pattern is detected, ria_stoff means where
          * stride read is started. Note: for normal read-ahead, the
-         * value here is meaningless, and also it will not be accessed*/ 
+         * value here is meaningless, and also it will not be accessed*/
         pgoff_t ria_stoff;
         /* ria_length and ria_pages are the length and pages length in the
          * stride I/O mode. And they will also be used to check whether
-         * it is stride I/O read-ahead in the read-ahead pages*/ 
+         * it is stride I/O read-ahead in the read-ahead pages*/
         unsigned long ria_length;
         unsigned long ria_pages;
 };
@@ -1230,20 +1469,20 @@ struct ra_io_arg {
 
 static inline int stride_io_mode(struct ll_readahead_state *ras)
 {
-        return ras->ras_consecutive_stride_requests > 1; 
+        return ras->ras_consecutive_stride_requests > 1;
 }
 
-/* The function calculates how much pages will be read in 
+/* The function calculates how much pages will be read in
  * [off, off + length], which will be read by stride I/O mode,
- * stride_offset = st_off, stride_lengh = st_len, 
+ * stride_offset = st_off, stride_lengh = st_len,
  * stride_pages = st_pgs
- */  
+ */
 static unsigned long
-stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs, 
+stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs,
                 unsigned long off, unsigned length)
 {
         unsigned long cont_len = st_off > off ?  st_off - off : 0;
-        unsigned long stride_len = length + off > st_off ?
+        __u64 stride_len = length + off > st_off ?
                            length + off + 1 - st_off : 0;
         unsigned long left, pg_count;
 
@@ -1258,17 +1497,17 @@ stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs,
         LASSERT(pg_count >= left);
 
         CDEBUG(D_READA, "st_off %lu, st_len %lu st_pgs %lu off %lu length %u"
-               "pgcount %lu\n", st_off, st_len, st_pgs, off, length, pg_count); 
+               "pgcount %lu\n", st_off, st_len, st_pgs, off, length, pg_count);
 
         return pg_count;
 }
 
 static int ria_page_count(struct ra_io_arg *ria)
 {
-        __u64 length = ria->ria_end >= ria->ria_start ? 
+        __u64 length = ria->ria_end >= ria->ria_start ?
                        ria->ria_end - ria->ria_start + 1 : 0;
 
-        return stride_pg_count(ria->ria_stoff, ria->ria_length, 
+        return stride_pg_count(ria->ria_stoff, ria->ria_length,
                                ria->ria_pages, ria->ria_start,
                                length);
 }
@@ -1277,10 +1516,10 @@ static int ria_page_count(struct ra_io_arg *ria)
 static int ras_inside_ra_window(unsigned long idx, struct ra_io_arg *ria)
 {
         /* If ria_length == ria_pages, it means non-stride I/O mode,
-         * idx should always inside read-ahead window in this case 
+         * idx should always inside read-ahead window in this case
          * For stride I/O mode, just check whether the idx is inside
          * the ria_pages. */
-        return ria->ria_length == 0 || ria->ria_length == ria->ria_pages || 
+        return ria->ria_length == 0 || ria->ria_length == ria->ria_pages ||
                (idx - ria->ria_stoff) % ria->ria_length < ria->ria_pages;
 }
 
@@ -1296,7 +1535,7 @@ static int ll_read_ahead_pages(struct obd_export *exp,
 
         LASSERT(ria != NULL);
         RIA_DEBUG(ria);
-      
+
         stride_ria = ria->ria_length > ria->ria_pages && ria->ria_pages > 0;
         for (page_idx = ria->ria_start; page_idx <= ria->ria_end &&
                         *reserved_pages > 0; page_idx++) {
@@ -1309,22 +1548,22 @@ static int ll_read_ahead_pages(struct obd_export *exp,
                        } else if (rc == -ENOLCK)
                                break;
                 } else if (stride_ria) {
-                        /* If it is not in the read-ahead window, and it is 
+                        /* If it is not in the read-ahead window, and it is
                          * read-ahead mode, then check whether it should skip
-                         * the stride gap */  
+                         * the stride gap */
                        pgoff_t offset;
-                        /* FIXME: This assertion only is valid when it is for 
-                         * forward read-ahead, it will be fixed when backward 
+                        /* FIXME: This assertion only is valid when it is for
+                         * forward read-ahead, it will be fixed when backward
                          * read-ahead is implemented */
                         LASSERTF(page_idx > ria->ria_stoff, "since %lu in the"
                                 " gap of ra window,it should bigger than stride"
                                 " offset %lu \n", page_idx, ria->ria_stoff);
-                        
+
                         offset = page_idx - ria->ria_stoff;
                        offset = offset % (ria->ria_length);
                        if (offset > ria->ria_pages) {
                                page_idx += ria->ria_length - offset;
-                                CDEBUG(D_READA, "i %lu skip %lu \n", page_idx, 
+                                CDEBUG(D_READA, "i %lu skip %lu \n", page_idx,
                                        ria->ria_length - offset);
                                 continue;
                         }
@@ -1339,13 +1578,13 @@ static int ll_readahead(struct ll_readahead_state *ras,
                          struct obd_io_group *oig, int flags)
 {
         unsigned long start = 0, end = 0, reserved;
-        unsigned long ra_end, len; 
+        unsigned long ra_end, len;
         struct inode *inode;
         struct lov_stripe_md *lsm;
         struct ll_ra_read *bead;
         struct ost_lvb lvb;
-        struct ra_io_arg ria = { 0 }; 
-        int ret = 0; 
+        struct ra_io_arg ria = { 0 };
+        int ret = 0;
         __u64 kms;
         ENTRY;
 
@@ -1381,26 +1620,27 @@ static int ll_readahead(struct ll_readahead_state *ras,
                 ras->ras_next_readahead = max(end, end + 1);
                 RAS_CDEBUG(ras);
         }
-       ria.ria_start = start;
-       ria.ria_end = end;
-       /* If stride I/O mode is detected, get stride window*/
-       if (stride_io_mode(ras)) {
-               ria.ria_length = ras->ras_stride_length; 
-               ria.ria_pages = ras->ras_stride_pages;
-       }
+        ria.ria_start = start;
+        ria.ria_end = end;
+        /* If stride I/O mode is detected, get stride window*/
+        if (stride_io_mode(ras)) {
+                ria.ria_stoff = ras->ras_stride_offset;
+                ria.ria_length = ras->ras_stride_length;
+                ria.ria_pages = ras->ras_stride_pages;
+        }
         spin_unlock(&ras->ras_lock);
 
         if (end == 0) {
                 ll_ra_stats_inc(mapping, RA_STAT_ZERO_WINDOW);
                 RETURN(0);
         }
-        len = ria_page_count(&ria); 
+        len = ria_page_count(&ria);
         if (len == 0)
                 RETURN(0);
+
         reserved = ll_ra_count_get(ll_i2sbi(inode), len);
 
-        if (reserved < end - start + 1)
+        if (reserved < len)
                 ll_ra_stats_inc(mapping, RA_STAT_MAX_IN_FLIGHT);
 
         CDEBUG(D_READA, "reserved page %lu \n", reserved);
@@ -1424,9 +1664,9 @@ static int ll_readahead(struct ll_readahead_state *ras,
 
         if (ra_end != (end + 1)) {
                 spin_lock(&ras->ras_lock);
-                if (ra_end < ras->ras_next_readahead && 
-                    index_in_window(ra_end, ras->ras_window_start, 0, 
-                                    ras->ras_window_len)) { 
+                if (ra_end < ras->ras_next_readahead &&
+                    index_in_window(ra_end, ras->ras_window_start, 0,
+                                    ras->ras_window_len)) {
                        ras->ras_next_readahead = ra_end;
                                RAS_CDEBUG(ras);
                 }
@@ -1471,16 +1711,16 @@ void ll_readahead_init(struct inode *inode, struct ll_readahead_state *ras)
 
 /* Check whether the read request is in the stride window.
  * If it is in the stride window, return 1, otherwise return 0.
- * and also update stride_gap and stride_pages. 
+ * and also update stride_gap and stride_pages.
  */
-static int index_in_stride_window(unsigned long index, 
+static int index_in_stride_window(unsigned long index,
                                   struct ll_readahead_state *ras,
                                   struct inode *inode)
 {
         int stride_gap = index - ras->ras_last_readpage - 1;
-        
+
         LASSERT(stride_gap != 0);
-        
+
         if (ras->ras_consecutive_pages == 0)
                 return 0;
 
@@ -1490,18 +1730,18 @@ static int index_in_stride_window(unsigned long index,
                 return 1;
 
         if (stride_gap >= 0) {
-                /* 
-                 * only set stride_pages, stride_length if 
+                /*
+                 * only set stride_pages, stride_length if
                  * it is forward reading ( stride_gap > 0)
                  */
                 ras->ras_stride_pages = ras->ras_consecutive_pages;
-                ras->ras_stride_length = stride_gap + ras->ras_consecutive_pages; 
+                ras->ras_stride_length = stride_gap + ras->ras_consecutive_pages;
         } else {
-                /* 
+                /*
                  * If stride_gap < 0,(back_forward reading),
-                 * reset the stride_pages/length. 
+                 * reset the stride_pages/length.
                  * FIXME:back_ward stride I/O read.
-                 * 
+                 *
                  */
                 ras->ras_stride_pages = 0;
                 ras->ras_stride_length = 0;
@@ -1521,7 +1761,7 @@ stride_page_count(struct ll_readahead_state *ras, unsigned long len)
 
 /* Stride Read-ahead window will be increased inc_len according to
  * stride I/O pattern */
-static void ras_stride_increase_window(struct ll_readahead_state *ras, 
+static void ras_stride_increase_window(struct ll_readahead_state *ras,
                                        struct ll_ra_info *ra,
                                        unsigned long inc_len)
 {
@@ -1533,18 +1773,18 @@ static void ras_stride_increase_window(struct ll_readahead_state *ras,
         stride_len = ras->ras_window_start + ras->ras_window_len -
                      ras->ras_stride_offset;
 
-        LASSERTF(stride_len > 0, "window_start %lu, window_len %lu"
-                "stride_offset %lu\n", ras->ras_window_start,
+        LASSERTF(stride_len >= 0, "window_start %lu, window_len %lu"
+                 " stride_offset %lu\n", ras->ras_window_start,
                  ras->ras_window_len, ras->ras_stride_offset);
 
         left = stride_len % ras->ras_stride_length;
 
         window_len = ras->ras_window_len - left;
-        
+
         if (left < ras->ras_stride_pages)
                 left += inc_len;
         else
-                left = ras->ras_stride_pages + inc_len; 
+                left = ras->ras_stride_pages + inc_len;
 
         LASSERT(ras->ras_stride_pages != 0);
 
@@ -1562,14 +1802,14 @@ static void ras_stride_increase_window(struct ll_readahead_state *ras,
 /* Set stride I/O read-ahead window start offset */
 static void ras_set_stride_offset(struct ll_readahead_state *ras)
 {
-        unsigned long window_len = ras->ras_next_readahead - 
+        unsigned long window_len = ras->ras_next_readahead -
                                    ras->ras_window_start;
-        unsigned long left;       
+        unsigned long left;
+
         LASSERT(ras->ras_stride_length != 0);
-       
+
         left = window_len % ras->ras_stride_length;
+
         ras->ras_stride_offset = ras->ras_next_readahead - left;
 
         RAS_CDEBUG(ras);
@@ -1583,10 +1823,9 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
         int zero = 0, stride_zero = 0, stride_detect = 0, ra_miss = 0;
         ENTRY;
 
-        spin_lock(&sbi->ll_lock);
         spin_lock(&ras->ras_lock);
 
-        ll_ra_stats_inc_unlocked(ra, hit ? RA_STAT_HIT : RA_STAT_MISS);
+        ll_ra_stats_inc_sbi(sbi, hit ? RA_STAT_HIT : RA_STAT_MISS);
 
         /* reset the read-ahead window in two cases.  First when the app seeks
          * or reads to some other part of the file.  Secondly if we get a
@@ -1595,7 +1834,7 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
          * reclaiming it before we get to it. */
         if (!index_in_window(index, ras->ras_last_readpage, 8, 8)) {
                 zero = 1;
-                ll_ra_stats_inc_unlocked(ra, RA_STAT_DISTANT_READPAGE);
+                ll_ra_stats_inc_sbi(sbi, RA_STAT_DISTANT_READPAGE);
                /* check whether it is in stride I/O mode*/
                 if (!index_in_stride_window(index, ras, inode))
                         stride_zero = 1;
@@ -1605,12 +1844,12 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
                                    ras->ras_window_len)) {
                 zero = 1;
                ra_miss = 1;
-                /* If it hits read-ahead miss and the stride I/O is still 
+                /* If it hits read-ahead miss and the stride I/O is still
                  * not detected, reset stride stuff to re-detect the whole
                  * stride I/O mode to avoid complication */
                 if (!stride_io_mode(ras))
                         stride_zero = 1;
-                ll_ra_stats_inc_unlocked(ra, RA_STAT_MISS_IN_WINDOW);
+                ll_ra_stats_inc_sbi(sbi, RA_STAT_MISS_IN_WINDOW);
         }
 
         /* On the second access to a file smaller than the tunable
@@ -1640,7 +1879,7 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
         }
 
         if (zero) {
-                /* If it is discontinuous read, check 
+                /* If it is discontinuous read, check
                  * whether it is stride I/O mode*/
                 if (stride_zero) {
                         ras_reset(ras, index);
@@ -1650,25 +1889,25 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
                         GOTO(out_unlock, 0);
                 } else {
                         /* The read is still in stride window or
-                        * it hits read-ahead miss */ 
+                        * it hits read-ahead miss */
 
-                        /* If ra-window miss is hitted, which probably means VM 
+                        /* If ra-window miss is hitted, which probably means VM
                          * pressure, and some read-ahead pages were reclaimed.So
-                         * the length of ra-window will not increased, but also  
-                         * not reset to avoid redetecting the stride I/O mode.*/ 
+                         * the length of ra-window will not increased, but also
+                         * not reset to avoid redetecting the stride I/O mode.*/
                        ras->ras_consecutive_requests = 0;
                         if (!ra_miss) {
                                 ras->ras_consecutive_pages = 0;
-                                if (++ras->ras_consecutive_stride_requests > 1) 
+                                if (++ras->ras_consecutive_stride_requests > 1)
                                         stride_detect = 1;
                         }
                         RAS_CDEBUG(ras);
                 }
         } else if (ras->ras_consecutive_stride_requests > 1) {
-                /* If this is contiguous read but in stride I/O mode 
+                /* If this is contiguous read but in stride I/O mode
                  * currently, check whether stride step still is valid,
                  * if invalid, it will reset the stride ra window*/    
-                if (ras->ras_consecutive_pages + 1 > ras->ras_stride_pages) 
+                if (ras->ras_consecutive_pages + 1 > ras->ras_stride_pages)
                         ras_stride_reset(ras);
         }
 
@@ -1693,13 +1932,13 @@ static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
         /* The initial ras_window_len is set to the request size.  To avoid
          * uselessly reading and discarding pages for random IO the window is
          * only increased once per consecutive request received. */
-        if ((ras->ras_consecutive_requests > 1 && 
+        if ((ras->ras_consecutive_requests > 1 &&
             !ras->ras_request_index) || stride_detect) {
                 if (stride_io_mode(ras))
-                        ras_stride_increase_window(ras, ra, RAS_INCREASE_STEP); 
-                else 
+                        ras_stride_increase_window(ras, ra, RAS_INCREASE_STEP);
+                else
                         ras->ras_window_len = min(ras->ras_window_len +
-                                                  RAS_INCREASE_STEP, 
+                                                  RAS_INCREASE_STEP,
                                                   ra->ra_max_pages);
         }
         EXIT;
@@ -1707,7 +1946,6 @@ out_unlock:
         RAS_CDEBUG(ras);
         ras->ras_request_index++;
         spin_unlock(&ras->ras_lock);
-        spin_unlock(&sbi->ll_lock);
         return;
 }
 
@@ -1730,6 +1968,7 @@ int ll_writepage(struct page *page)
         if (IS_ERR(llap))
                 GOTO(out, rc = PTR_ERR(llap));
 
+        LASSERT(!llap->llap_nocache);
         LASSERT(!PageWriteback(page));
         set_page_writeback(page);
 
@@ -1743,19 +1982,22 @@ int ll_writepage(struct page *page)
                 rc = queue_or_sync_write(exp, inode, llap, CFS_PAGE_SIZE,
                                          ASYNC_READY | ASYNC_URGENT);
         }
-        if (rc)
-                page_cache_release(page);
-out:
         if (rc) {
-                if (!lli->lli_async_rc)
-                        lli->lli_async_rc = rc;
                 /* re-dirty page on error so it retries write */
-                if (PageWriteback(page)) {
+                if (PageWriteback(page))
                         end_page_writeback(page);
-                }
+
                 /* resend page only for not started IO*/
                 if (!PageError(page))
                         ll_redirty_page(page);
+
+                page_cache_release(page);
+        }
+out:
+        if (rc) {
+                if (!lli->lli_async_rc)
+                        lli->lli_async_rc = rc;
+                /* resend page only for not started IO*/
                 unlock_page(page);
         }
         RETURN(rc);
@@ -1777,6 +2019,7 @@ int ll_readpage(struct file *filp, struct page *page)
         struct obd_export *exp;
         struct ll_async_page *llap;
         struct obd_io_group *oig = NULL;
+        struct lustre_handle *lockh = NULL;
         int rc;
         ENTRY;
 
@@ -1808,9 +2051,19 @@ int ll_readpage(struct file *filp, struct page *page)
         if (exp == NULL)
                 GOTO(out, rc = -EINVAL);
 
-        llap = llap_from_page(page, LLAP_ORIGIN_READPAGE);
-        if (IS_ERR(llap))
+        if (fd->fd_flags & LL_FILE_GROUP_LOCKED)
+                lockh = &fd->fd_cwlockh;
+
+        llap = llap_from_page_with_lockh(page, LLAP_ORIGIN_READPAGE, lockh);
+        if (IS_ERR(llap)) {
+                if (PTR_ERR(llap) == -ENOLCK) {
+                        CWARN("ino %lu page %lu (%llu) not covered by "
+                              "a lock (mmap?).  check debug logs.\n",
+                              inode->i_ino, page->index,
+                              (long long)page->index << PAGE_CACHE_SHIFT);
+                }
                 GOTO(out, rc = PTR_ERR(llap));
+        }
 
         if (ll_i2sbi(inode)->ll_ra_info.ra_max_pages)
                 ras_update(ll_i2sbi(inode), inode, &fd->fd_ras, page->index,
@@ -1831,22 +2084,6 @@ int ll_readpage(struct file *filp, struct page *page)
                 GOTO(out_oig, rc = 0);
         }
 
-        if (likely((fd->fd_flags & LL_FILE_IGNORE_LOCK) == 0)) {
-                rc = ll_page_matches(page, fd->fd_flags);
-                if (rc < 0) {
-                        LL_CDEBUG_PAGE(D_ERROR, page,
-                                       "lock match failed: rc %d\n", rc);
-                        GOTO(out, rc);
-                }
-
-                if (rc == 0) {
-                        CWARN("ino %lu page %lu (%llu) not covered by "
-                              "a lock (mmap?).  check debug logs.\n",
-                              inode->i_ino, page->index,
-                              (long long)page->index << CFS_PAGE_SHIFT);
-                }
-        }
-
         rc = ll_issue_page_read(exp, llap, oig, 0);
         if (rc)
                 GOTO(out, rc);
@@ -1868,3 +2105,274 @@ out_oig:
                 oig_release(oig);
         RETURN(rc);
 }
+
+static void ll_file_put_pages(struct page **pages, int numpages)
+{
+        int i;
+        struct page **pp;
+        ENTRY;
+
+        for (i = 0, pp = pages; i < numpages; i++, pp++) {
+                if (*pp) {
+                        LL_CDEBUG_PAGE(D_PAGE, (*pp), "free\n");
+                        __ll_put_llap(*pp);
+                        if (page_private(*pp))
+                                CERROR("the llap wasn't freed\n");
+                        (*pp)->mapping = NULL;
+                        if (page_count(*pp) != 1)
+                                CERROR("page %p, flags %#lx, count %i, private %p\n",
+                                (*pp), (unsigned long)(*pp)->flags, page_count(*pp),
+                                (void*)page_private(*pp));
+                        __free_pages(*pp, 0);
+                }
+        }
+        OBD_FREE(pages, numpages * sizeof(struct page*));
+        EXIT;
+}
+
+static struct page **ll_file_prepare_pages(int numpages, struct inode *inode,
+                                           unsigned long first)
+{
+        struct page **pages;
+        int i;
+        int rc = 0;
+        ENTRY;
+
+        OBD_ALLOC(pages, sizeof(struct page *) * numpages);
+        if (pages == NULL)
+                RETURN(ERR_PTR(-ENOMEM));
+        for (i = 0; i < numpages; i++) {
+                struct page *page;
+                struct ll_async_page *llap;
+
+                page = alloc_pages(GFP_HIGHUSER, 0);
+                if (page == NULL)
+                        GOTO(err, rc = -ENOMEM);
+                pages[i] = page;
+                /* llap_from_page needs page index and mapping to be set */
+                page->index = first++;
+                page->mapping = inode->i_mapping;
+                llap = llap_from_page(page, LLAP_ORIGIN_LOCKLESS_IO);
+                if (IS_ERR(llap))
+                        GOTO(err, rc = PTR_ERR(llap));
+                llap->llap_lockless_io_page = 1;
+        }
+        RETURN(pages);
+err:
+        ll_file_put_pages(pages, numpages);
+        RETURN(ERR_PTR(rc));
+ }
+
+static ssize_t ll_file_copy_pages(struct page **pages, int numpages,
+                                  char *buf, loff_t pos, size_t count, int rw)
+{
+        ssize_t amount = 0;
+        int i;
+        int updatechecksum = ll_i2sbi(pages[0]->mapping->host)->ll_flags &
+                             LL_SBI_CHECKSUM;
+        ENTRY;
+
+        for (i = 0; i < numpages; i++) {
+                unsigned offset, bytes, left;
+                char *vaddr;
+
+                vaddr = kmap(pages[i]);
+                offset = pos & (CFS_PAGE_SIZE - 1);
+                bytes = min_t(unsigned, CFS_PAGE_SIZE - offset, count);
+                LL_CDEBUG_PAGE(D_PAGE, pages[i], "op = %s, addr = %p, "
+                               "buf = %p, bytes = %u\n",
+                               (rw == WRITE) ? "CFU" : "CTU",
+                               vaddr + offset, buf, bytes);
+                if (rw == WRITE) {
+                        left = copy_from_user(vaddr + offset, buf, bytes);
+                        if (updatechecksum) {
+                                struct ll_async_page *llap;
+
+                                llap = llap_cast_private(pages[i]);
+                                llap->llap_checksum = crc32_le(0, vaddr,
+                                                               CFS_PAGE_SIZE);
+                        }
+                } else {
+                        left = copy_to_user(buf, vaddr + offset, bytes);
+                }
+                kunmap(pages[i]);
+                amount += bytes;
+                if (left) {
+                        amount -= left;
+                        break;
+                }
+                buf += bytes;
+                count -= bytes;
+                pos += bytes;
+        }
+        if (amount == 0)
+                RETURN(-EFAULT);
+        RETURN(amount);
+}
+
+static int ll_file_oig_pages(struct inode * inode, struct page **pages,
+                             int numpages, loff_t pos, size_t count, int rw)
+{
+        struct obd_io_group *oig;
+        struct ll_inode_info *lli = ll_i2info(inode);
+        struct obd_export *exp;
+        loff_t org_pos = pos;
+        obd_flag brw_flags;
+        int rc;
+        int i;
+        ENTRY;
+
+        exp = ll_i2dtexp(inode);
+        if (exp == NULL)
+                RETURN(-EINVAL);
+        rc = oig_init(&oig);
+        if (rc)
+                RETURN(rc);
+        brw_flags = OBD_BRW_SRVLOCK;
+        if (capable(CAP_SYS_RESOURCE))
+                brw_flags |= OBD_BRW_NOQUOTA;
+
+        for (i = 0; i < numpages; i++) {
+                struct ll_async_page *llap;
+                unsigned from, bytes;
+
+                from = pos & (CFS_PAGE_SIZE - 1);
+                bytes = min_t(unsigned, CFS_PAGE_SIZE - from,
+                              count - pos + org_pos);
+                llap = llap_cast_private(pages[i]);
+                LASSERT(llap);
+
+                lock_page(pages[i]);
+
+                LL_CDEBUG_PAGE(D_PAGE, pages[i], "offset "LPU64","
+                               " from %u, bytes = %u\n",
+                               (__u64)pos, from, bytes);
+                LASSERTF(pos >> CFS_PAGE_SHIFT == pages[i]->index,
+                         "wrong page index %lu (%lu)\n",
+                         pages[i]->index,
+                         (unsigned long)(pos >> CFS_PAGE_SHIFT));
+                rc = obd_queue_group_io(exp, lli->lli_smd, NULL, oig,
+                                        llap->llap_cookie,
+                                        (rw == WRITE) ?
+                                        OBD_BRW_WRITE:OBD_BRW_READ,
+                                        from, bytes, brw_flags,
+                                        ASYNC_READY | ASYNC_URGENT |
+                                        ASYNC_COUNT_STABLE | ASYNC_GROUP_SYNC);
+                if (rc) {
+                        i++;
+                        GOTO(out, rc);
+                }
+                pos += bytes;
+        }
+        rc = obd_trigger_group_io(exp, lli->lli_smd, NULL, oig);
+        if (rc)
+                GOTO(out, rc);
+        rc = oig_wait(oig);
+out:
+        while(--i >= 0)
+                unlock_page(pages[i]);
+        oig_release(oig);
+        RETURN(rc);
+}
+
+ssize_t ll_file_lockless_io(struct file *file, char *buf, size_t count,
+                                   loff_t *ppos, int rw)
+{
+        loff_t pos;
+        struct inode *inode = file->f_dentry->d_inode;
+        ssize_t rc = 0;
+        int max_pages;
+        size_t amount = 0;
+        unsigned long first, last;
+        ENTRY;
+
+        if (rw == READ) {
+                loff_t isize;
+
+                ll_inode_size_lock(inode, 0);
+                isize = i_size_read(inode);
+                ll_inode_size_unlock(inode, 0);
+                if (*ppos >= isize)
+                        GOTO(out, rc = 0);
+                if (*ppos + count >= isize)
+                        count -= *ppos + count - isize;
+                if (count == 0)
+                        GOTO(out, rc);
+        } else {
+                rc = generic_write_checks(file, ppos, &count, 0);
+                if (rc)
+                        GOTO(out, rc);
+                rc = ll_remove_suid(file->f_dentry, file->f_vfsmnt);
+                if (rc)
+                        GOTO(out, rc);
+        }
+        pos = *ppos;
+        first = pos >> CFS_PAGE_SHIFT;
+        last = (pos + count - 1) >> CFS_PAGE_SHIFT;
+        max_pages = PTLRPC_MAX_BRW_PAGES *
+                ll_i2info(inode)->lli_smd->lsm_stripe_count;
+        CDEBUG(D_INFO, "%u, stripe_count = %u\n",
+               PTLRPC_MAX_BRW_PAGES /* max_pages_per_rpc */,
+               ll_i2info(inode)->lli_smd->lsm_stripe_count);
+
+        while (first <= last && rc >= 0) {
+                int pages_for_io;
+                struct page **pages;
+                size_t bytes = count - amount;
+
+                pages_for_io = min_t(int, last - first + 1, max_pages);
+                pages = ll_file_prepare_pages(pages_for_io, inode, first);
+                if (IS_ERR(pages)) {
+                        rc = PTR_ERR(pages);
+                        break;
+                }
+                if (rw == WRITE) {
+                        rc = ll_file_copy_pages(pages, pages_for_io, buf,
+                                                pos + amount, bytes, rw);
+                        if (rc < 0)
+                                GOTO(put_pages, rc);
+                        bytes = rc;
+                }
+                rc = ll_file_oig_pages(inode, pages, pages_for_io,
+                                       pos + amount, bytes, rw);
+                if (rc)
+                        GOTO(put_pages, rc);
+                if (rw == READ) {
+                        rc = ll_file_copy_pages(pages, pages_for_io, buf,
+                                                pos + amount, bytes, rw);
+                        if (rc < 0)
+                                GOTO(put_pages, rc);
+                        bytes = rc;
+                }
+                amount += bytes;
+                buf += bytes;
+put_pages:
+                ll_file_put_pages(pages, pages_for_io);
+                first += pages_for_io;
+                /* a short read/write check */
+                if (pos + amount < ((loff_t)first << CFS_PAGE_SHIFT))
+                        break;
+        }
+        /* NOTE: don't update i_size and KMS in absence of LDLM locks even
+         * write makes the file large */
+        file_accessed(file);
+        if (rw == READ && amount < count && rc == 0) {
+                unsigned long not_cleared;
+
+                not_cleared = clear_user(buf, count - amount);
+                amount = count - not_cleared;
+                if (not_cleared)
+                        rc = -EFAULT;
+        }
+        if (amount > 0) {
+                lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
+                                    (rw == WRITE) ?
+                                    LPROC_LL_LOCKLESS_WRITE :
+                                    LPROC_LL_LOCKLESS_READ,
+                                    (long)amount);
+                *ppos += amount;
+                RETURN(amount);
+        }
+out:
+        RETURN(rc);
+}