/* -*- 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>
//#include <lustre_mdc.h>
#include <lustre_lite.h>
+#include <obd_cksum.h>
#include "llite_internal.h"
#include <linux/lustre_compat25.h>
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
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),
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
}
}
- 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;
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;
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
* 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);
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;
}
page_cache_get(page);
- spin_unlock(&sbi->ll_lock);
+ ll_pglist_cpu_unlock(sbi, cpu);
if (page->mapping != NULL) {
ll_teardown_mmaps(page->mapping,
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) {
/* 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);
}
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);
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);
/* 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)) {
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) {
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)
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))
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;
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));
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.*/
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) {
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);
* 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,
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)
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;
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) {
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);
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
* 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;
* 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
RAS_CDEBUG(ras);
ras->ras_request_index++;
spin_unlock(&ras->ras_lock);
- spin_unlock(&sbi->ll_lock);
return;
}
if (IS_ERR(llap))
GOTO(out, rc = PTR_ERR(llap));
+ LASSERT(!llap->llap_nocache);
LASSERT(!PageWriteback(page));
set_page_writeback(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);
struct obd_export *exp;
struct ll_async_page *llap;
struct obd_io_group *oig = NULL;
+ struct lustre_handle *lockh = NULL;
int rc;
ENTRY;
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,
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);
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);
+}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff