+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
- * Copyright (c) 2002, 2003 Cluster File Systems, Inc.
- *
- * This file is part of Lustre, http://www.lustre.org.
- *
- * 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.
- *
- * 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.
- *
- * 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.
- *
- * Copyright (C) 2002, 2003 Cluster File Systems, Inc
- *
- * this started as an implementation of an io daemon that woke regularly
- * to force writeback.. the throttling in prepare_write and kupdate's usual
- * writeback pressure got rid of our thread, but the file name remains.
- */
-
-#include <linux/version.h>
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/stat.h>
-#include <linux/sched.h>
-#include <linux/smp_lock.h>
-#include <linux/kmod.h>
-#include <linux/pagemap.h>
-#include <linux/mm.h>
-#include <linux/rbtree.h>
-#include <linux/seq_file.h>
-#include <linux/time.h>
-#include <linux/wait.h>
-
-/* PG_inactive_clean is shorthand for rmap, we want free_high/low here.. */
-#ifdef PG_inactive_clean
-#include <linux/mm_inline.h>
-#endif
-
-#define DEBUG_SUBSYSTEM S_LLITE
-#include <linux/lustre_lite.h>
-#include "llite_internal.h"
-
-#ifndef list_for_each_prev_safe
-#define list_for_each_prev_safe(pos, n, head) \
- for (pos = (head)->prev, n = pos->prev; pos != (head); \
- pos = n, n = pos->prev )
-#endif
-
-extern spinlock_t inode_lock;
-
-/*
- * check to see if we're racing with truncate and put the page in
- * the brw_page array. returns 0 if there is more room and 1
- * if the array is full.
- */
-static int llwp_consume_page(struct ll_writeback_pages *llwp,
- struct inode *inode, struct page *page)
-{
- obd_off off = ((obd_off)page->index) << PAGE_SHIFT;
- struct brw_page *pg;
-
- /* we raced with truncate? */
- if ( off >= inode->i_size ) {
- ll_end_writeback(inode, page);
- return 0;
- }
-
- page_cache_get(page);
- pg = &llwp->pga[llwp->npgs];
- llwp->npgs++;
- LASSERT(llwp->npgs <= llwp->max);
-
- pg->pg = page;
- pg->off = off;
- pg->flag = OBD_BRW_CREATE|OBD_BRW_FROM_GRANT;
- pg->count = PAGE_CACHE_SIZE;
-
- /* catch partial writes for files that end mid-page */
- if (pg->off + pg->count > inode->i_size)
- pg->count = inode->i_size & ~PAGE_CACHE_MASK;
-
- /*
- * matches ptlrpc_bulk_get assert that trickles down
- * from a 0 page length going through niobuf and into
- * the buffer regions being posted
- */
- LASSERT(pg->count >= 0);
-
- CDEBUG(D_CACHE, "brw_page %p: off "LPU64" cnt %d, page %p: ind %ld"
- " i_size: %llu\n", pg, pg->off, pg->count, page,
- page->index, inode->i_size);
-
- return llwp->npgs == llwp->max;
-}
-
-/*
- * returns the number of pages that it added to the pgs array
- *
- * this duplicates filemap_fdatasync and gives us an opportunity to grab lots
- * of dirty pages..
- */
-static void ll_get_dirty_pages(struct inode *inode,
- struct ll_writeback_pages *llwp)
-{
- struct address_space *mapping = inode->i_mapping;
- struct page *page;
- struct list_head *pos, *n;
- ENTRY;
-
- ll_pgcache_lock(mapping);
-
- list_for_each_prev_safe(pos, n, &mapping->dirty_pages) {
- page = list_entry(pos, struct page, list);
-
- if (TryLockPage(page))
- continue;
-
- list_del(&page->list);
- list_add(&page->list, &mapping->locked_pages);
-
- if (!PageDirty(page)) {
- unlock_page(page);
- continue;
- }
- ClearPageDirty(page);
-
- if (llwp_consume_page(llwp, inode, page) != 0)
- break;
- }
-
- ll_pgcache_unlock(mapping);
- EXIT;
-}
-
-static void ll_writeback(struct inode *inode, struct obdo *oa,
- struct ll_writeback_pages *llwp)
-{
- struct ptlrpc_request_set *set;
- int rc, i;
- ENTRY;
-
- CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p),bytes=%u\n",
- inode->i_ino, inode->i_generation, inode,
- ((llwp->npgs-1) << PAGE_SHIFT) + llwp->pga[llwp->npgs-1].count);
-
- SIGNAL_MASK_ASSERT(); /* XXX BUG 1511 */
- set = ptlrpc_prep_set();
- if (set == NULL) {
- CERROR ("Can't create request set\n");
- rc = -ENOMEM;
- } else {
- rc = obd_brw_async(OBD_BRW_WRITE, ll_i2obdconn(inode), oa,
- ll_i2info(inode)->lli_smd, llwp->npgs,
- llwp->pga, set, NULL);
- if (rc == 0)
- rc = ptlrpc_set_wait(set);
- if (rc == 0) {
- /* bug 1598: don't clobber blksize */
- oa->o_valid &= ~(OBD_MD_FLSIZE | OBD_MD_FLBLKSZ);
- obdo_refresh_inode(inode, oa, oa->o_valid);
- }
- ptlrpc_set_destroy(set);
- }
- /*
- * b=1038, we need to pass _brw errors up so that writeback
- * doesn't get stuck in recovery leaving processes stuck in
- * D waiting for pages
- */
- if (rc) {
- CERROR("error from obd_brw_async: rc = %d\n", rc);
- lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
- LPROC_LL_WB_FAIL, llwp->npgs);
- } else {
- lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
- LPROC_LL_WB_OK, (llwp->npgs));
- }
-
- for (i = 0 ; i < llwp->npgs ; i++) {
- struct page *page = llwp->pga[i].pg;
-
- ll_end_writeback(inode, page);
- page_cache_release(page); /* to match llwp_consume_page */
- }
-
- EXIT;
-}
-
-static struct ll_writeback_pages *llwp_alloc(struct inode *inode)
-{
- struct ll_writeback_pages *llwp;
- int size, max = (inode->i_blksize >> PAGE_CACHE_SHIFT);
-
- if (max == 0) {
- CERROR("forcing llwp->max to 1. blksize: %lu\n",
- inode->i_blksize);
- max = 1;
- }
- size = sizeof(*llwp) + (max * sizeof(struct brw_page));
-
- OBD_ALLOC(llwp, size);
- if (llwp == NULL)
- RETURN(ERR_PTR(-ENOMEM));
- llwp->max = max;
-/* XXX don't worry, this will be gone before you know it.. */
-#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
- llwp->inode = inode;
-#endif
-
- RETURN(llwp);
-}
-
-void llwp_free(struct ll_writeback_pages *llwp)
-{
- int size = sizeof(*llwp) + (llwp->max * sizeof(struct brw_page));
- OBD_FREE(llwp, size);
-}
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
-
-/* 2.4 doesn't give us a way to find out how many pages we have cached 'cause
- * we're not using buffer_heads. we are very conservative here and flush the
- * superblock of all dirty data when the vm (rmap or stock) thinks that it is
- * running low and kswapd would have done work. kupdated isn't good enough
- * because writers (dbench) can dirty _very quickly_, and we allocate under
- * writepage..
- */
-#ifdef PG_inactive_clean /* 2.4 rmap */
-
-static int should_writeback(void)
-{
- if (free_high(ALL_ZONES) > 0 || free_low(ANY_ZONE) > 0)
- return 1;
- return 0;
-}
-
-# else /* stock 2.4 -aa zone vm */
-
-#ifdef CONFIG_DISCONTIGMEM
-#error "sorry, we don't support DISCONTIGMEM"
-#endif
-/*
- * __alloc_pages marks a zone as needing balancing if an allocation is
- * performed when the zone has fewer free pages than its 'low' water
- * mark. its cleared when try_to_free_pages makes progress.
- */
-static int should_writeback(void) /* aka zones_need_balancing */
-{
- pg_data_t * pgdat;
- zone_t *zone;
- int i;
-
- for ( pgdat = pgdat_list ; pgdat != NULL ; pgdat = pgdat->node_next ) {
- for ( i = pgdat->nr_zones-1 ; i >= 0 ; i-- ) {
- zone = &pgdat->node_zones[i];
-
- if ( zone->need_balance )
- return 1;
- }
- }
- return 0;
-}
-#endif /* PG_inactive_clean detection of rmap vs stock */
-
-int ll_check_dirty(struct super_block *sb)
-{
- unsigned long old_flags; /* hack? */
- int making_progress;
- struct inode *inode;
- struct obdo oa;
- int rc = 0;
- ENTRY;
-
- if (!should_writeback())
- return 0;
-
- old_flags = current->flags;
- current->flags |= PF_MEMALLOC;
-
- spin_lock(&inode_lock);
- /*
- * we're trying to use a very awkward hammer to throttle lustre's
- * dirty data here. as long as the vm thinks we're "low" we're
- * finding dirty inodes and writing out all their data. the
- * second while loop is waiting for other threads who are doing
- * the same thing.. we ran into livelocks if one thread was able
- * to blow through here not finding dirty inodes because another
- * thread was busy writing them back..
- *
- * XXX this is all goofy because low memory can stop it from
- * working properly. someday we'll be pre-allocating io context
- * in prepare_write/commit_write.
- */
- do {
- struct ll_writeback_pages *llwp;
- struct list_head *pos;
- inode = NULL;
- making_progress = 0;
-
- list_for_each_prev(pos, &sb->s_dirty) {
- inode = list_entry(pos, struct inode, i_list);
-
- if (!(inode->i_state & I_DIRTY_PAGES)) {
- inode = NULL;
- continue;
- }
- break;
- }
-
- if (inode == NULL)
- break;
-
- /* lock the inode while we work on it, which duplicates
- * __sync_one */
- list_del(&inode->i_list);
- list_add(&inode->i_list, &inode->i_sb->s_locked_inodes);
- inode->i_state |= I_LOCK;
- inode->i_state &= ~I_DIRTY_PAGES;
-
- spin_unlock(&inode_lock);
- llwp = llwp_alloc(inode);
- spin_lock(&inode_lock);
-
- if (IS_ERR(llwp)) /* making_progress == 0 will break the loop */
- goto unlock_inode;
-
- spin_unlock(&inode_lock);
-
- do {
- llwp->npgs = 0;
- ll_get_dirty_pages(inode, llwp);
- if (llwp->npgs) {
- oa.o_id =
- ll_i2info(inode)->lli_smd->lsm_object_id;
- oa.o_valid = OBD_MD_FLID;
- obdo_from_inode(&oa, inode,
- OBD_MD_FLTYPE|OBD_MD_FLATIME|
- OBD_MD_FLMTIME|OBD_MD_FLCTIME);
-
- lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
- LPROC_LL_WB_PRESSURE,
- llwp->npgs);
- ll_writeback(inode, &oa, llwp);
- rc += llwp->npgs;
- making_progress = 1;
- }
- } while (llwp->npgs && should_writeback());
-
- llwp_free(llwp);
-
- spin_lock(&inode_lock);
-
-unlock_inode:
- if (!list_empty(&inode->i_mapping->dirty_pages))
- inode->i_state |= I_DIRTY_PAGES;
-
- inode->i_state &= ~I_LOCK;
- /*
- * we are sneaky and leave the inode on the dirty list,
- * even though it might not still be..
- */
- if (!(inode->i_state & I_FREEING)) {
- list_del(&inode->i_list);
- list_add(&inode->i_list, &inode->i_sb->s_dirty);
- }
- wake_up(&inode->i_wait);
- } while (making_progress && should_writeback());
-
- /*
- * and if that didn't work, we sleep on any data that might
- * be under writeback..
- */
- while (should_writeback()) {
- if (list_empty(&sb->s_locked_inodes))
- break;
-
- inode = list_entry(sb->s_locked_inodes.next, struct inode,
- i_list);
-
- atomic_inc(&inode->i_count); /* XXX hack? */
- spin_unlock(&inode_lock);
- wait_event(inode->i_wait, !(inode->i_state & I_LOCK));
- iput(inode);
- spin_lock(&inode_lock);
- }
-
- spin_unlock(&inode_lock);
-
- current->flags = old_flags;
- RETURN(rc);
-}
-
-/* called from writepage and allows us to also try and write out other
- * pages. only called from 2.4 because 2.5 has ->writepages() */
-int ll_batch_writepage(struct inode *inode, struct obdo *oa, struct page *page)
-{
- unsigned long old_flags; /* hack? */
- struct ll_writeback_pages *llwp;
- int rc = 0;
- ENTRY;
-
- SIGNAL_MASK_ASSERT(); /* XXX BUG 1511 */
- old_flags = current->flags;
- current->flags |= PF_MEMALLOC;
- llwp = llwp_alloc(inode);
- if (IS_ERR(llwp))
- GOTO(restore_flags, PTR_ERR(llwp));
-
- if (llwp_consume_page(llwp, inode, page) == 0)
- ll_get_dirty_pages(inode, llwp);
-
- if (llwp->npgs) {
- lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
- LPROC_LL_WB_WRITEPAGE, llwp->npgs);
- ll_writeback(inode, oa, llwp);
- }
- llwp_free(llwp);
-
-restore_flags:
- current->flags = old_flags;
- RETURN(rc);
-}
-#endif
-
-#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
-/* we use a singly linked list of page->private to pass pages between
- * readpage/writepage and our worker threads without allocating things
- * and while maintaining fifo order.. */
-void plist_init(struct plist *plist) {
- plist->pl_head = NULL;
- plist->pl_tail = NULL;
- plist->pl_num = 0;
-}
-struct page *plist_get_page(struct plist *plist) {
- struct page *page = plist->pl_head;
-
- if (page == NULL)
- return NULL;
-
- plist->pl_head = (struct page *)page->private;
- if (page == plist->pl_tail)
- plist->pl_tail = NULL;
- plist->pl_num--;
- page->private = 0;
-
- return page;
-}
-void plist_move(struct plist *to, struct plist *from)
-{
- if (to->pl_head == NULL)
- *to = *from;
- else {
- to->pl_tail->private = (unsigned long)from->pl_head;
- to->pl_tail = from->pl_tail;
- to->pl_num += from->pl_num;
- }
- plist_init(from);
-}
-void plist_add_page(struct plist *plist, struct page *page)
-{
- LASSERT(page->private == 0);
- if (plist->pl_tail) {
- plist->pl_tail->private = (unsigned long)page;
- plist->pl_tail = page;
- } else {
- plist->pl_head = page;
- plist->pl_tail = page;
- }
- plist->pl_num++;
-}
-
-void lliod_wakeup(struct inode *inode)
-{
- struct lliod_ctl *lc = &ll_i2sbi(inode)->ll_lc;
- wake_up(&lc->lc_waitq);
- lc->lc_new_arrival = 1;
-}
-
-/* wake_lliod can be skipped if the path knows that more lliod_give_s will
- * be coming before the path waits on the pages.. it must be called before
- * waiting so that new_arrival is set and lliod comes out of its l_wait */
-void lliod_give_plist(struct inode *inode, struct plist *plist, int rw)
-{
- struct ll_inode_info *lli = ll_i2info(inode);
- struct lliod_ctl *lc = &ll_i2sbi(inode)->ll_lc;
-
- CDEBUG(D_CACHE, "rw: %d plist %p num %d\n", rw, plist,
- plist ? plist->pl_num : 0);
-
- if (plist)
- LASSERT(rw == OBD_BRW_READ || rw == OBD_BRW_WRITE);
-
- spin_lock(&lc->lc_lock);
- if (list_empty(&lli->lli_lc_item))
- list_add_tail(&lli->lli_lc_item, &lc->lc_lli_list);
-
- if (plist) {
- if (rw == OBD_BRW_WRITE)
- plist_move(&lli->lli_pl_write, plist);
- else
- plist_move(&lli->lli_pl_read, plist);
- }
- spin_unlock(&lc->lc_lock);
-}
-
-void lliod_give_page(struct inode *inode, struct page *page, int rw)
-{
- struct plist plist;
-
- plist_init(&plist);
- plist_add_page(&plist, page);
- lliod_give_plist(inode, &plist, rw);
-}
-
-/* XXX should so something smart with the 'rc' depending on the failover
- * configuration */
-void lliod_complete_llwp(struct inode *inode, struct ll_writeback_pages *llwp,
- int rc)
-{
- struct page *page;
- int i;
-
- CDEBUG(D_CACHE, "inode: %p rw: %d rc: %d\n", inode, llwp->rw, rc);
-
- for (i = 0 ; i < llwp->npgs ; i++) {
- page = llwp->pga[i].pg;
-
- CDEBUG(D_CACHE, "page: %p index: %lu\n", page, page->index);
- if (llwp->rw == OBD_BRW_WRITE)
- ll_end_writeback(inode, page);
- else {
- SetPageUptodate(page);
- unlock_page(page);
- }
-
- page_cache_release(page); /* to match llwp_consume_page */
- }
-}
-
-/* ok, the clump thing wasn't so hot, lets just do brws as writepage hands
- * us pages. to avoid inter-inode or read/write starvation we take the
- * pages off the lli and then consume them all, first reads then writes */
-int lliod_brw(struct lliod_ctl *lc)
-{
- struct inode *inode = NULL;
- struct ll_inode_info *lli = NULL;
- struct ll_writeback_pages *llwp;
- struct ptlrpc_request_set *set = NULL;
- struct page *page;
- struct plist plist_read, plist_write, *plist;
- int rc = 0, rw, tmp;
- ENTRY;
-
- plist_init(&plist_read);
- plist_init(&plist_write);
-
- spin_lock(&lc->lc_lock);
- if (list_empty(&lc->lc_lli_list)) {
- spin_unlock(&lc->lc_lock);
- RETURN(0);
- }
-
- lli = list_entry(lc->lc_lli_list.next, struct ll_inode_info,
- lli_lc_item);
- inode = ll_info2i(lli);
- list_del_init(&lli->lli_lc_item);
-
- plist_move(&plist_read, &lli->lli_pl_read);
- plist_move(&plist_write, &lli->lli_pl_write);
-
- spin_unlock(&lc->lc_lock);
-
- llwp = llwp_alloc(inode);
- if (IS_ERR(llwp)) {
- rc = -ENOMEM;
- goto out;
- }
-
- if (plist_read.pl_num) {
- plist = &plist_read;
- rw = OBD_BRW_READ;
- } else {
- plist = &plist_write;
- rw = OBD_BRW_WRITE;
- }
-
- CDEBUG(D_CACHE, "inode %p #r: %d #w: %d\n", inode, plist_read.pl_num,
- plist_write.pl_num);
-
- while (plist->pl_num > 0) {
- struct obdo oa;
-
- set = ptlrpc_prep_set();
- if (set == NULL) {
- rc = -ENOMEM;
- break;
- }
-
- llwp->npgs = 0;
- llwp->rw = rw;
- llwp->inode = inode;
- while ((page = plist_get_page(plist))) {
- tmp = llwp_consume_page(llwp, inode, page);
- page_cache_release(page); /* from writepage */
- if (tmp)
- break;
- }
- oa.o_id = lli->lli_smd->lsm_object_id;
- oa.o_valid = OBD_MD_FLID;
- obdo_from_inode(&oa, inode, OBD_MD_FLTYPE | OBD_MD_FLATIME |
- OBD_MD_FLMTIME | OBD_MD_FLCTIME);
- tmp = obd_brw_async(rw, ll_i2obdconn(inode), &oa,
- ll_i2info(inode)->lli_smd,
- llwp->npgs, llwp->pga, set, NULL);
- if (tmp == 0)
- tmp = ptlrpc_set_wait(set);
-
- ptlrpc_set_destroy(set);
- lliod_complete_llwp(inode, llwp, tmp);
-
- if (plist->pl_num == 0 && rw == OBD_BRW_READ) {
- plist = &plist_write;
- rw = OBD_BRW_WRITE;
- }
- }
-
- llwp_free(llwp);
-out:
- if (rc) {
- lliod_give_plist(inode, &plist_read, OBD_BRW_READ);
- lliod_give_plist(inode, &plist_write, OBD_BRW_WRITE);
- }
-
- RETURN(rc);
-}
-
-static int lliod(void *arg)
-{
- struct lliod_ctl *lc = arg;
- ENTRY;
-
- kportal_daemonize("liod_writeback");
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
- sigfillset(¤t->blocked);
- recalc_sigpending();
-#else
- spin_lock_irqsave(¤t->sigmask_lock, flags);
- sigfillset(¤t->blocked);
- recalc_sigpending(current);
- spin_unlock_irqrestore(¤t->sigmask_lock, flags);
-#endif
-
- complete(&lc->lc_starting);
-
- /* like kswapd */
- current->flags |= PF_MEMALLOC;
-
- while (1) {
-
- /* XXX re-using the clu waitq for now; its harmless..
- * we'll update the path depending on clu's fate */
- wait_event_interruptible(lc->lc_waitq,
- ( test_bit(LIOD_STOP, &lc->lc_flags) ||
- (!list_empty(&lc->lc_lli_list)) ) );
-
- if (test_bit(LIOD_STOP, &lc->lc_flags))
- break;
-
- /* sleep for a short amount of time if we get -ENOMEM,
- * maybe giving the world a chance to free some memory
- * for us */
- if (lliod_brw(lc)) {
- set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(HZ/100);
- }
-
- }
- /* XXX should be making sure we don't have inodes/
- * pages still in flight */
- complete(&lc->lc_finishing);
- return 0;
-}
-
-int lliod_start(struct ll_sb_info *sbi, struct inode *inode)
-{
- struct lliod_ctl *lc = &sbi->ll_lc;
- ENTRY;
-
- init_completion(&lc->lc_starting);
- init_completion(&lc->lc_finishing);
- INIT_LIST_HEAD(&lc->lc_lli_list);
- init_waitqueue_head(&lc->lc_waitq);
- lc->lc_flags = 0;
- lc->lc_new_arrival = 0;
- spin_lock_init(&lc->lc_lock);
-
- if (kernel_thread(lliod, &sbi->ll_lc, 0) < 0)
- RETURN(-ECHILD);
-
- wait_for_completion(&lc->lc_starting);
- RETURN(0);
-}
-
-void lliod_stop(struct ll_sb_info *sbi)
-{
- struct lliod_ctl *lc = &sbi->ll_lc;
-
- set_bit(LIOD_STOP, &lc->lc_flags);
- wake_up(&lc->lc_waitq);
- wait_for_completion(&lc->lc_finishing);
-}
-#endif /* 2.5 check.. */
git://git.whamcloud.com / fs / lustre-release.git / commitdiff