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Gentoo's Bugzilla – Attachment 261781 Details for
Bug 354055
kernel - add support / help test raid1 new read_balance code
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raid1.c new source code
raid1.new.c (text/plain), 73.65 KB, created by
Roberto Spadim
on 2011-02-08 03:58:41 UTC
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Description:
raid1.c new source code
Filename:
MIME Type:
Creator:
Roberto Spadim
Created:
2011-02-08 03:58:41 UTC
Size:
73.65 KB
patch
obsolete
>/* > * raid1.c : Multiple Devices driver for Linux > * > * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat > * > * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman > * > * RAID-1 management functions. > * > * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000 > * > * > * New read-balancing modes: > * Near head - default read balance (Mika Kuoppala, 2000) > * Round Robin - Roy Keene (linux-raid@kneene.org, 2010) > * per mirror count by Roberto Spadim (roberto@spadim.com.br, 2011) > * Stripe - Per sector disk selector (like raid0 stripe), based on this_sector, read_balance_stripe_shift and conf->raid_mirrors > * by Roberto Spadim (roberto@spadim.com.br, 2011) > * Time Based - Per mirror I/O time estimator by Roberto Spadim (roberto@spadim.com.br, 2011) > * need some improvement, per mirror queue time estimator isn't used (yet) > * > * > * Fixes to reconstruction by Jakob Ãstergaard" <jakob@ostenfeld.dk> > * Various fixes by Neil Brown <neilb@cse.unsw.edu.au> > * > * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support > * bitmapped intelligence in resync: > * > * - bitmap marked during normal i/o > * - bitmap used to skip nondirty blocks during sync > * > * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology: > * - persistent bitmap code > * > * This program is free software; you can redistribute it and/or modify > * it under the terms of the GNU General Public License as published by > * the Free Software Foundation; either version 2, or (at your option) > * any later version. > * > * You should have received a copy of the GNU General Public License > * (for example /usr/src/linux/COPYING); if not, write to the Free > * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > */ > >#include <linux/slab.h> >#include <linux/delay.h> >#include <linux/blkdev.h> >#include <linux/seq_file.h> >#include "md.h" >#include "raid1.h" >#include "bitmap.h" > >#define DEBUG 0 >#if DEBUG >#define PRINTK(x...) printk(x) >#else >#define PRINTK(x...) >#endif > >/* > * Number of guaranteed r1bios in case of extreme VM load: > */ >#define NR_RAID1_BIOS 256 > > >static void unplug_slaves(mddev_t *mddev); > >static void allow_barrier(conf_t *conf); >static void lower_barrier(conf_t *conf); > >/* begin of - sysfs inteface for read balance options */ >static ssize_t raid1_show_read_balance_config(mddev_t *mddev, char *page) >{ > /* should change this inteface, and make it per mirror like: > * /sys/block/md0/md/dev-sda/head_distance_rate > * /sys/block/md0/md/dev-sda/head_fixed_time > * /sys/block/md0/md/dev-sda/read_sectors_rate > * /sys/block/md0/md/dev-sda/write_sectors_rate > */ > conf_t *conf = mddev->private; > int size=0,i=0; > char b[BDEVNAME_SIZE]; > > if (!conf) { > return(-ENODEV); > } > > size+=sprintf(page, "mirror_index " > "head_distance_rate " > "head_fixed_time " > "head_shift_unit " > "read_sectors_rate " > "read_shift_unit " > "write_sectors_rate " > "write_shift_unit " > "round_robin_max | " > "round_robin_count " > "current_head_position " > "mirror_device_name\n"); > for( i=0; i < conf->raid_disks ; i++){ > size+=sprintf(page, "%s%i %li %li %i %li %i %li %i %li | %li %li %s\n", > page, > i, > (long int)conf->mirrors[i].head_distance_rate, > (long int)conf->mirrors[i].head_fixed_time, > (int) conf->mirrors[i].head_shift_unit, > (long int)conf->mirrors[i].read_sectors_rate, > (int) conf->mirrors[i].read_shift_unit, > (long int)conf->mirrors[i].write_sectors_rate, > (int) conf->mirrors[i].write_shift_unit, > (long int)conf->mirrors[i].round_robin_max, > (long int)conf->mirrors[i].round_robin_count, > (long int)conf->mirrors[i].head_position, > bdevname(conf->mirrors[i].rdev->bdev,b) > ); > if(size>=3000){ /* max size?? */ > break; > } > } > return size; >} >static ssize_t raid1_store_read_balance_config(mddev_t *mddev, const char *page, size_t len) >{ > conf_t *conf = mddev->private; > long int p2,p3,p5,p7,p9; > int p1,p4,p6,p8; > if (!conf) { > return(-ENODEV); > } > > sscanf(page, "%i %li %li %i %li %i %li %i %li", &p1,&p2,&p3,&p4,&p5,&p6,&p7,&p8,&p9); > if(p1<0 || p1>=conf->raid_disks){ > printk(KERN_ERR "raid1_read_balance_config [%i] not found on raid_disks\n",p1); > return -EINVAL; > } > if(p2<0){ > printk(KERN_ERR "raid1_read_balance_config [%li] not allowed for head_distance_rate\n",p2); > return -EINVAL; > } > if(p3<0){ > printk(KERN_ERR "raid1_read_balance_config [%li] not allowed for head_fixed_time\n",p3); > return -EINVAL; > } > if(p4<0){ > printk(KERN_ERR "raid1_read_balance_config [%i] not allowed for head_shift_unit\n",p4); > return -EINVAL; > } > if(p5<0){ > printk(KERN_ERR "raid1_read_balance_config [%li] not allowed for read_sectors_rate\n",p5); > return -EINVAL; > } > if(p6<0){ > printk(KERN_ERR "raid1_read_balance_config [%i] not allowed for read_shift_unit\n",p6); > return -EINVAL; > } > if(p7<0){ > printk(KERN_ERR "raid1_read_balance_config [%li] not allowed for write_sectors_rate\n",p7); > return -EINVAL; > } > if(p8<0){ > printk(KERN_ERR "raid1_read_balance_config [%i] not allowed for write_shift_unit\n",p8); > return -EINVAL; > } > if(p9<=0 || p9>=0xdfffffff){ > printk(KERN_ERR "raid1_read_balance_config [%li] not allowed for round_robin_max\n",p9); > return -EINVAL; > } > conf->mirrors[p1].head_distance_rate =p2; > conf->mirrors[p1].head_fixed_time =p3; > conf->mirrors[p1].head_shift_unit =p4; > conf->mirrors[p1].read_sectors_rate =p5; > conf->mirrors[p1].read_shift_unit =p6; > conf->mirrors[p1].write_sectors_rate =p7; > conf->mirrors[p1].write_shift_unit =p8; > conf->mirrors[p1].round_robin_max =p9; > return(len); > >/* > * example how to calculate time based values , using mixed SSD/HD with diferent rates/access time in same array > *=================================================================================================== > *HD > * sectors =16777216 > * accestime =10ms (access rate: time/sectors) > * read rate =130mb/s (130mb/512b=266240 sector/s) > * > *10ms accesstime= 0,00000000059604644775390625 s/sector (time/ total sectors) > *266240 sec/s read rate= 0,00000375600961538461 s/sector (change mb/s to sector/s, and invert s/sectors) > * > *=================================================================================================== > *SSD > * sectors =16777216 > * fixed accestime =0.1ms (access rate: time/sectors) > * read rate =270mb/s (270mb/512b=552960 sector/s) > * > *fixed access time= 0,0000000000059604644775390625 s/sector (fixed time/ total sectors) > *552960 sec/s read rate= 0,000001808449074074 s/sector (same as hd) > * > *=================================================================================================== > *MIN UNIT OF TIME = 0,0000000000059604644775390625 s/sector (use this time to make disks values) > *=================================================================================================== > *HD) > *HEAD_DISTANCE_RATE = 100 > *HEAD_FIXED_TIME = 0 > *HEAD_SHIFT_UNIT = 0 > *READ_SECTORS_RATE = 630100 (read rate / (accesstime / sectors)) > *READ_SHIFT_UNIT = 0 > * > *=================================================================================================== > *SSD) > *HEAD_DISTANCE_RATE = 0 > *HEAD_FIXED_TIME = 1 > *HEAD_SHIFT_UNIT = 0 > *READ_SECTORS_RATE = 303407 (read rate / (accesstime / sectors)) > *READ_SHIFT_UNIT = 0 > * > *=================================================================================================== > */ > > > >} >static ssize_t raid1_show_read_balance_stripe_shift(mddev_t *mddev, char *page) >{ > conf_t *conf = mddev->private; > if (!conf) { > return(-ENODEV); > } > return sprintf(page, "%i\n",conf->read_balance_stripe_shift); >} >static ssize_t raid1_store_read_balance_stripe_shift(mddev_t *mddev, const char *page, size_t len) >{ > conf_t *conf = mddev->private; > unsigned long tmp_new_value; > if (!conf) { > return(-ENODEV); > } > if(strict_strtoul(page,10,&tmp_new_value)){ > return -EINVAL; > } > if(tmp_new_value<0){ > conf->read_balance_stripe_shift=0; > }else if(tmp_new_value>128){ > conf->read_balance_stripe_shift=128; > }else{ > conf->read_balance_stripe_shift=(int)tmp_new_value; > } > return(len); >} >static ssize_t raid1_show_read_balance_mode(mddev_t *mddev, char *page) >{ > conf_t *conf = mddev->private; > if (!conf) { > return(-ENODEV); > } > if (conf->read_balance_mode==3) > return sprintf(page, "near_head round_robin time_based [stripe]\n"); > else if(conf->read_balance_mode==2) > return sprintf(page, "near_head round_robin [time_based] stripe\n"); > else if(conf->read_balance_mode==1) > return sprintf(page, "near_head [round_robin] time_based stripe\n"); > return sprintf(page, "[near_head] round_robin time_based stripe\n"); >} >static ssize_t raid1_store_read_balance_mode(mddev_t *mddev, const char *page, size_t len) >{ > conf_t *conf = mddev->private; > if (!conf) { > return(-ENODEV); > } > if (strncmp(page,"near_head",16)==0 || strncmp(page,"near_head\n",16)==0){ > conf->read_balance_mode=0; > }else if(strncmp(page,"time_based",16)==0 || strncmp(page,"time_based\n",16)==0){ > conf->read_balance_mode=2; > }else if(strncmp(page,"round_robin",16)==0 || strncmp(page,"round_robin\n",16)==0){ > conf->read_balance_mode=1; > }else if(strncmp(page,"stripe",16)==0 || strncmp(page,"stripe\n",16)==0){ > conf->read_balance_mode=3; > }else{ > printk(KERN_ERR "raid1_read_balance_mode [%s] not found\n",page); > return -EINVAL; > } > return len; >} > >static struct md_sysfs_entry raid1_read_balance_mode = __ATTR( > read_balance_mode, > S_IRUGO | S_IWUSR, raid1_show_read_balance_mode, > raid1_store_read_balance_mode); >static struct md_sysfs_entry raid1_read_balance_stripe_shift = __ATTR( > read_balance_stripe_shift, > S_IRUGO | S_IWUSR, raid1_show_read_balance_stripe_shift, > raid1_store_read_balance_stripe_shift); >static struct md_sysfs_entry raid1_read_balance_config = __ATTR( > read_balance_config, > S_IRUGO | S_IWUSR, raid1_show_read_balance_config, > raid1_store_read_balance_config); >static struct attribute *raid1_attrs[] = { > &raid1_read_balance_mode.attr, > &raid1_read_balance_stripe_shift.attr, > &raid1_read_balance_config.attr, > NULL >}; > >// &raid1_read_balance_stripe_shift.attr, > >static struct attribute_group raid1_attrs_group = { > .name = NULL, > .attrs = raid1_attrs, >}; >/* end of - sysfs inteface for read balance option */ > > >static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) >{ > struct pool_info *pi = data; > r1bio_t *r1_bio; > int size = offsetof(r1bio_t, bios[pi->raid_disks]); > /* allocate a r1bio with room for raid_disks entries in the bios array */ > r1_bio = kzalloc(size, gfp_flags); > if (!r1_bio && pi->mddev) > unplug_slaves(pi->mddev); > > return r1_bio; >} > >static void r1bio_pool_free(void *r1_bio, void *data) >{ > kfree(r1_bio); >} > >#define RESYNC_BLOCK_SIZE (64*1024) >//#define RESYNC_BLOCK_SIZE PAGE_SIZE >#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) >#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) >#define RESYNC_WINDOW (2048*1024) > >static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) >{ > struct pool_info *pi = data; > struct page *page; > r1bio_t *r1_bio; > struct bio *bio; > int i, j; > > r1_bio = r1bio_pool_alloc(gfp_flags, pi); > if (!r1_bio) { > unplug_slaves(pi->mddev); > return NULL; > } > > /* > * Allocate bios : 1 for reading, n-1 for writing > */ > for (j = pi->raid_disks ; j-- ; ) { > bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); > if (!bio) > goto out_free_bio; > r1_bio->bios[j] = bio; > } > /* > * Allocate RESYNC_PAGES data pages and attach them to > * the first bio. > * If this is a user-requested check/repair, allocate > * RESYNC_PAGES for each bio. > */ > if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) > j = pi->raid_disks; > else > j = 1; > while(j--) { > bio = r1_bio->bios[j]; > for (i = 0; i < RESYNC_PAGES; i++) { > page = alloc_page(gfp_flags); > if (unlikely(!page)) > goto out_free_pages; > > bio->bi_io_vec[i].bv_page = page; > bio->bi_vcnt = i+1; > } > } > /* If not user-requests, copy the page pointers to all bios */ > if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { > for (i=0; i<RESYNC_PAGES ; i++) > for (j=1; j<pi->raid_disks; j++) > r1_bio->bios[j]->bi_io_vec[i].bv_page = > r1_bio->bios[0]->bi_io_vec[i].bv_page; > } > > r1_bio->master_bio = NULL; > > return r1_bio; > >out_free_pages: > for (j=0 ; j < pi->raid_disks; j++) > for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++) > put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page); > j = -1; >out_free_bio: > while ( ++j < pi->raid_disks ) > bio_put(r1_bio->bios[j]); > r1bio_pool_free(r1_bio, data); > return NULL; >} > >static void r1buf_pool_free(void *__r1_bio, void *data) >{ > struct pool_info *pi = data; > int i,j; > r1bio_t *r1bio = __r1_bio; > > for (i = 0; i < RESYNC_PAGES; i++) > for (j = pi->raid_disks; j-- ;) { > if (j == 0 || > r1bio->bios[j]->bi_io_vec[i].bv_page != > r1bio->bios[0]->bi_io_vec[i].bv_page) > safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page); > } > for (i=0 ; i < pi->raid_disks; i++) > bio_put(r1bio->bios[i]); > > r1bio_pool_free(r1bio, data); >} > >static void put_all_bios(conf_t *conf, r1bio_t *r1_bio) >{ > int i; > > for (i = 0; i < conf->raid_disks; i++) { > struct bio **bio = r1_bio->bios + i; > if (*bio && *bio != IO_BLOCKED) > bio_put(*bio); > *bio = NULL; > } >} > >static void free_r1bio(r1bio_t *r1_bio) >{ > conf_t *conf = r1_bio->mddev->private; > > /* > * Wake up any possible resync thread that waits for the device > * to go idle. > */ > allow_barrier(conf); > > put_all_bios(conf, r1_bio); > mempool_free(r1_bio, conf->r1bio_pool); >} > >static void put_buf(r1bio_t *r1_bio) >{ > conf_t *conf = r1_bio->mddev->private; > int i; > > for (i=0; i<conf->raid_disks; i++) { > struct bio *bio = r1_bio->bios[i]; > if (bio->bi_end_io) > rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev); > } > > mempool_free(r1_bio, conf->r1buf_pool); > > lower_barrier(conf); >} > >static void reschedule_retry(r1bio_t *r1_bio) >{ > unsigned long flags; > mddev_t *mddev = r1_bio->mddev; > conf_t *conf = mddev->private; > > spin_lock_irqsave(&conf->device_lock, flags); > list_add(&r1_bio->retry_list, &conf->retry_list); > conf->nr_queued ++; > spin_unlock_irqrestore(&conf->device_lock, flags); > > wake_up(&conf->wait_barrier); > md_wakeup_thread(mddev->thread); >} > >/* > * raid_end_bio_io() is called when we have finished servicing a mirrored > * operation and are ready to return a success/failure code to the buffer > * cache layer. > */ >static void raid_end_bio_io(r1bio_t *r1_bio) >{ > struct bio *bio = r1_bio->master_bio; > > /* if nobody has done the final endio yet, do it now */ > if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { > PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n", > (bio_data_dir(bio) == WRITE) ? "write" : "read", > (unsigned long long) bio->bi_sector, > (unsigned long long) bio->bi_sector + > (bio->bi_size >> 9) - 1); > > bio_endio(bio, > test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); > } > free_r1bio(r1_bio); >} > >/* > * Update disk head position estimator based on IRQ completion info. > */ >static inline void update_head_pos(int disk, r1bio_t *r1_bio) >{ > conf_t *conf = r1_bio->mddev->private; > > conf->mirrors[disk].head_position = > r1_bio->sector + (r1_bio->sectors); >} > >static void raid1_end_read_request(struct bio *bio, int error) >{ > int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); > r1bio_t *r1_bio = bio->bi_private; > int mirror; > conf_t *conf = r1_bio->mddev->private; > > mirror = r1_bio->read_disk; > /* > * this branch is our 'one mirror IO has finished' event handler: > */ > update_head_pos(mirror, r1_bio); > > if (uptodate) > set_bit(R1BIO_Uptodate, &r1_bio->state); > else { > /* If all other devices have failed, we want to return > * the error upwards rather than fail the last device. > * Here we redefine "uptodate" to mean "Don't want to retry" > */ > unsigned long flags; > spin_lock_irqsave(&conf->device_lock, flags); > if (r1_bio->mddev->degraded == conf->raid_disks || > (r1_bio->mddev->degraded == conf->raid_disks-1 && > !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))) > uptodate = 1; > spin_unlock_irqrestore(&conf->device_lock, flags); > } > > if (uptodate) > raid_end_bio_io(r1_bio); > else { > /* > * oops, read error: > */ > char b[BDEVNAME_SIZE]; > if (printk_ratelimit()) > printk(KERN_ERR "md/raid1:%s: %s: rescheduling sector %llu\n", > mdname(conf->mddev), > bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector); > reschedule_retry(r1_bio); > } > > rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); >} > >static void r1_bio_write_done(r1bio_t *r1_bio, int vcnt, struct bio_vec *bv, > int behind) >{ > if (atomic_dec_and_test(&r1_bio->remaining)) > { > /* it really is the end of this request */ > if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { > /* free extra copy of the data pages */ > int i = vcnt; > while (i--) > safe_put_page(bv[i].bv_page); > } > /* clear the bitmap if all writes complete successfully */ > bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, > r1_bio->sectors, > !test_bit(R1BIO_Degraded, &r1_bio->state), > behind); > md_write_end(r1_bio->mddev); > raid_end_bio_io(r1_bio); > } >} > >static void raid1_end_write_request(struct bio *bio, int error) >{ > int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); > r1bio_t *r1_bio = bio->bi_private; > int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state); > conf_t *conf = r1_bio->mddev->private; > struct bio *to_put = NULL; > > > for (mirror = 0; mirror < conf->raid_disks; mirror++) > if (r1_bio->bios[mirror] == bio) > break; > > /* > * 'one mirror IO has finished' event handler: > */ > r1_bio->bios[mirror] = NULL; > to_put = bio; > if (!uptodate) { > md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); > /* an I/O failed, we can't clear the bitmap */ > set_bit(R1BIO_Degraded, &r1_bio->state); > } else > /* > * Set R1BIO_Uptodate in our master bio, so that we > * will return a good error code for to the higher > * levels even if IO on some other mirrored buffer > * fails. > * > * The 'master' represents the composite IO operation > * to user-side. So if something waits for IO, then it > * will wait for the 'master' bio. > */ > set_bit(R1BIO_Uptodate, &r1_bio->state); > > update_head_pos(mirror, r1_bio); > > if (behind) { > if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) > atomic_dec(&r1_bio->behind_remaining); > > /* > * In behind mode, we ACK the master bio once the I/O > * has safely reached all non-writemostly > * disks. Setting the Returned bit ensures that this > * gets done only once -- we don't ever want to return > * -EIO here, instead we'll wait > */ > if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && > test_bit(R1BIO_Uptodate, &r1_bio->state)) { > /* Maybe we can return now */ > if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { > struct bio *mbio = r1_bio->master_bio; > PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", > (unsigned long long) mbio->bi_sector, > (unsigned long long) mbio->bi_sector + > (mbio->bi_size >> 9) - 1); > bio_endio(mbio, 0); > } > } > } > rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); > > /* > * Let's see if all mirrored write operations have finished > * already. > */ > r1_bio_write_done(r1_bio, bio->bi_vcnt, bio->bi_io_vec, behind); > > if (to_put) > bio_put(to_put); >} > > >/* > * This routine returns the disk from which the requested read should > * be done. There is a per-array 'next expected sequential IO' sector > * number - if this matches on the next IO then we use the last disk. > * There is also a per-disk 'last know head position' sector that is > * maintained from IRQ contexts, both the normal and the resync IO > * completion handlers update this position correctly. If there is no > * perfect sequential match then we pick the disk whose head is closest. > * > * If there are 2 mirrors in the same 2 devices, performance degrades > * because position is mirror, not device based. > * > * The rdev for the device selected will have nr_pending incremented. > */ >static int read_balance(conf_t *conf, r1bio_t *r1_bio) >{ > const sector_t this_sector = r1_bio->sector; > const int sectors = r1_bio->sectors; > int new_disk = -1; > int start_disk; > int i; > sector_t new_distance, current_distance; > mdk_rdev_t *rdev; > int choose_first; > > int time_based_best_disk=-1; > long long int time_based_min_time; > long long int time_based_current_access_time; > long long int time_based_current_read_time; > long long int time_based_current_queue_time; > long long int time_based_current_time; > > rcu_read_lock(); > /* > * Check if we can balance. We can balance on the whole > * device if no resync is going on, or below the resync window. > * We take the first readable disk when above the resync window. > */ > > /* time based, select start best operational disk, if it fail we will use near head read balance */ > if(conf->read_balance_mode==2){ > time_based_min_time =-1; > /* this operation cost cpu and ram (long int based) */ > /* based on distance, read_rate, i/o */ > for (i = 0 ; i < conf->raid_disks ; i++) { > rdev = rcu_dereference(conf->mirrors[i].rdev); > /* just work with good disks */ > if (r1_bio->bios[i] == IO_BLOCKED > || rdev == NULL > || !test_bit(In_sync, &rdev->flags)) > continue; > time_based_current_access_time =0; > time_based_current_read_time =0; > time_based_current_queue_time =0; > time_based_current_time =0; > > /* access time: */ > if(conf->mirrors[i].head_distance_rate>0){ > if(this_sector>=conf->mirrors[i].head_position) > current_distance = this_sector - conf->mirrors[i].head_position; > else > current_distance = conf->mirrors[i].head_position - this_sector; > if(current_distance>=0xdfffffff) // >= 30bit, change to 30bit (too high number) > current_distance=0xdfffffff; > time_based_current_access_time =current_distance * conf->mirrors[i].head_distance_rate; > } > if(conf->mirrors[i].head_fixed_time>0) > time_based_current_access_time +=conf->mirrors[i].head_fixed_time; > if(conf->mirrors[i].head_shift_unit>0) > time_based_current_access_time =time_based_current_access_time>>conf->mirrors[i].head_shift_unit; > > /* read time: */ > if(conf->mirrors[i].read_sectors_rate>0){ > time_based_current_read_time =sectors * conf->mirrors[i].read_sectors_rate; > if(conf->mirrors[i].read_shift_unit>0) > time_based_current_read_time =time_based_current_read_time>>conf->mirrors[i].read_shift_unit; > } > > /* queue time: */ > time_based_current_queue_time =0; /* > * maybe a function (per elevator?) that return: > * total numbers of write sectors, > * total number of read sectors, > * first and last sector position (head movement) > * time = > * total number of write * write time / write_div + > * total number of read * read time / read_div + > * (distance * head_distance_rate + head_fixed_time) / head_div; > */ > time_based_current_time=time_based_current_queue_time+ > time_based_current_read_time+ > time_based_current_access_time; > if(time_based_min_time<0 && > (time_based_current_time>=0 && > time_based_current_time<time_based_min_time)){ > time_based_best_disk =i; > time_based_min_time =time_based_current_time; > } > } > if(time_based_best_disk>=0){ > new_disk = time_based_best_disk; > // avoid a lot of cpu/memory use > goto rb_out; > } > } > > > retry: > if (conf->mddev->recovery_cp < MaxSector && > (this_sector + sectors >= conf->next_resync)) { > choose_first = 1; > start_disk = 0; > } else { > choose_first = 0; > /* near head */ > start_disk = conf->last_used; > if(conf->read_balance_mode==2 && time_based_best_disk>=0){ /* time based best disk */ > start_disk=time_based_best_disk; > }else if(conf->read_balance_mode==3){ /* stripe mode*/ > if(conf->read_balance_stripe_shift>0){ /* avoid 64 bit operation */ > start_disk=(this_sector >> conf->read_balance_stripe_shift) & 0x0fff; > }else{ > start_disk=(this_sector & 0x0fff); > } > if(start_disk<0) /* avoid problem with this_sector(u64) convertion to int */ > start_disk=-start_disk; > start_disk=start_disk % conf->raid_disks; > }else if(conf->read_balance_mode==1){ /* round-robin mode*/ > if(conf->mirrors[start_disk].round_robin_count>= > conf->mirrors[start_disk].round_robin_max){ > /* next disk */ > conf->mirrors[start_disk].round_robin_count=0; > start_disk=(start_disk+1) % conf->raid_disks; > }else{ > conf->mirrors[start_disk].round_robin_count++; > /* add + 1 on counter */ > } > } > } >/* printk("START DISK: %i %lu \n", start_disk, (long unsigned int)this_sector); */ > > /* make sure the disk is operational */ > /* operational = io not blocked and block in sync */ > for (i = 0 ; i < conf->raid_disks ; i++) { > int disk = start_disk + i; > if (disk >= conf->raid_disks) > disk -= conf->raid_disks; > > rdev = rcu_dereference(conf->mirrors[disk].rdev); > if (r1_bio->bios[disk] == IO_BLOCKED > || rdev == NULL > || !test_bit(In_sync, &rdev->flags)) > continue; > > new_disk = disk; > if (!test_bit(WriteMostly, &rdev->flags)) > break; > } > > /* round-robin mode no best disk, just the next operational disk */ > /* stripe no best disk, just the stripe operational disk */ > /* if time based, new disk must be the best disk, if not use near head :( */ > if (new_disk < 0 || > choose_first || > conf->read_balance_mode==1 || > conf->read_balance_mode==3 || > (conf->read_balance_mode==2 && time_based_best_disk==new_disk) > ){ > time_based_best_disk=-1; /* just allow 1 time based execution, if no operational disk use near head or roundrobin*/ > goto rb_out; > } > time_based_best_disk=-1; > /*near_head:*/ > /* > * Don't change to another disk for sequential reads: > * that's just for near head (round robin and time based don't need it, just if can select a good disk > */ > if (conf->next_seq_sect == this_sector) > goto rb_out; > if (this_sector == conf->mirrors[new_disk].head_position) > goto rb_out; > > if(this_sector>=conf->mirrors[new_disk].head_position) > current_distance = this_sector - conf->mirrors[new_disk].head_position; > else > current_distance = conf->mirrors[new_disk].head_position - this_sector; > > /* look for a better disk - i.e. head is closer */ > start_disk = new_disk; > for (i = 1; i < conf->raid_disks; i++) { > int disk = start_disk + 1; > if (disk >= conf->raid_disks) > disk -= conf->raid_disks; > > rdev = rcu_dereference(conf->mirrors[disk].rdev); > if (r1_bio->bios[disk] == IO_BLOCKED > || rdev == NULL > || !test_bit(In_sync, &rdev->flags) > || test_bit(WriteMostly, &rdev->flags)) > continue; > > if (!atomic_read(&rdev->nr_pending)) { > new_disk = disk; > break; > } > if(this_sector>=conf->mirrors[disk].head_position) > new_distance = this_sector - conf->mirrors[disk].head_position; > else > new_distance = conf->mirrors[disk].head_position - this_sector; > if (new_distance < current_distance) { > current_distance = new_distance; > new_disk = disk; > } > } > > rb_out: > if (new_disk >= 0) { > rdev = rcu_dereference(conf->mirrors[new_disk].rdev); > if (!rdev) > goto retry; > atomic_inc(&rdev->nr_pending); > if (!test_bit(In_sync, &rdev->flags)) { > /* cannot risk returning a device that failed > * before we inc'ed nr_pending > */ > rdev_dec_pending(rdev, conf->mddev); > goto retry; > } > conf->next_seq_sect = this_sector + sectors; > conf->last_used = new_disk; > } > rcu_read_unlock(); > >/* printk("SELECTED DISK: %i %lu \n", new_disk, (long unsigned int)this_sector); */ > return new_disk; >} > >static void unplug_slaves(mddev_t *mddev) >{ > conf_t *conf = mddev->private; > int i; > > rcu_read_lock(); > for (i=0; i<mddev->raid_disks; i++) { > mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); > if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { > struct request_queue *r_queue = bdev_get_queue(rdev->bdev); > > atomic_inc(&rdev->nr_pending); > rcu_read_unlock(); > > blk_unplug(r_queue); > > rdev_dec_pending(rdev, mddev); > rcu_read_lock(); > } > } > rcu_read_unlock(); >} > >static void raid1_unplug(struct request_queue *q) >{ > mddev_t *mddev = q->queuedata; > > unplug_slaves(mddev); > md_wakeup_thread(mddev->thread); >} > >static int raid1_congested(void *data, int bits) >{ > mddev_t *mddev = data; > conf_t *conf = mddev->private; > int i, ret = 0; > > if (mddev_congested(mddev, bits)) > return 1; > > rcu_read_lock(); > for (i = 0; i < mddev->raid_disks; i++) { > mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); > if (rdev && !test_bit(Faulty, &rdev->flags)) { > struct request_queue *q = bdev_get_queue(rdev->bdev); > > /* Note the '|| 1' - when read_balance prefers > * non-congested targets, it can be removed > */ > if ((bits & (1<<BDI_async_congested)) || 1) > ret |= bdi_congested(&q->backing_dev_info, bits); > else > ret &= bdi_congested(&q->backing_dev_info, bits); > } > } > rcu_read_unlock(); > return ret; >} > > >static int flush_pending_writes(conf_t *conf) >{ > /* Any writes that have been queued but are awaiting > * bitmap updates get flushed here. > * We return 1 if any requests were actually submitted. > */ > int rv = 0; > > spin_lock_irq(&conf->device_lock); > > if (conf->pending_bio_list.head) { > struct bio *bio; > bio = bio_list_get(&conf->pending_bio_list); > blk_remove_plug(conf->mddev->queue); > spin_unlock_irq(&conf->device_lock); > /* flush any pending bitmap writes to > * disk before proceeding w/ I/O */ > bitmap_unplug(conf->mddev->bitmap); > > while (bio) { /* submit pending writes */ > struct bio *next = bio->bi_next; > bio->bi_next = NULL; > generic_make_request(bio); > bio = next; > } > rv = 1; > } else > spin_unlock_irq(&conf->device_lock); > return rv; >} > >/* Barriers.... > * Sometimes we need to suspend IO while we do something else, > * either some resync/recovery, or reconfigure the array. > * To do this we raise a 'barrier'. > * The 'barrier' is a counter that can be raised multiple times > * to count how many activities are happening which preclude > * normal IO. > * We can only raise the barrier if there is no pending IO. > * i.e. if nr_pending == 0. > * We choose only to raise the barrier if no-one is waiting for the > * barrier to go down. This means that as soon as an IO request > * is ready, no other operations which require a barrier will start > * until the IO request has had a chance. > * > * So: regular IO calls 'wait_barrier'. When that returns there > * is no backgroup IO happening, It must arrange to call > * allow_barrier when it has finished its IO. > * backgroup IO calls must call raise_barrier. Once that returns > * there is no normal IO happeing. It must arrange to call > * lower_barrier when the particular background IO completes. > */ >#define RESYNC_DEPTH 32 > >static void raise_barrier(conf_t *conf) >{ > spin_lock_irq(&conf->resync_lock); > > /* Wait until no block IO is waiting */ > wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, > conf->resync_lock, > raid1_unplug(conf->mddev->queue)); > > /* block any new IO from starting */ > conf->barrier++; > > /* Now wait for all pending IO to complete */ > wait_event_lock_irq(conf->wait_barrier, > !conf->nr_pending && conf->barrier < RESYNC_DEPTH, > conf->resync_lock, > raid1_unplug(conf->mddev->queue)); > > spin_unlock_irq(&conf->resync_lock); >} > >static void lower_barrier(conf_t *conf) >{ > unsigned long flags; > BUG_ON(conf->barrier <= 0); > spin_lock_irqsave(&conf->resync_lock, flags); > conf->barrier--; > spin_unlock_irqrestore(&conf->resync_lock, flags); > wake_up(&conf->wait_barrier); >} > >static void wait_barrier(conf_t *conf) >{ > spin_lock_irq(&conf->resync_lock); > if (conf->barrier) { > conf->nr_waiting++; > wait_event_lock_irq(conf->wait_barrier, !conf->barrier, > conf->resync_lock, > raid1_unplug(conf->mddev->queue)); > conf->nr_waiting--; > } > conf->nr_pending++; > spin_unlock_irq(&conf->resync_lock); >} > >static void allow_barrier(conf_t *conf) >{ > unsigned long flags; > spin_lock_irqsave(&conf->resync_lock, flags); > conf->nr_pending--; > spin_unlock_irqrestore(&conf->resync_lock, flags); > wake_up(&conf->wait_barrier); >} > >static void freeze_array(conf_t *conf) >{ > /* stop syncio and normal IO and wait for everything to > * go quite. > * We increment barrier and nr_waiting, and then > * wait until nr_pending match nr_queued+1 > * This is called in the context of one normal IO request > * that has failed. Thus any sync request that might be pending > * will be blocked by nr_pending, and we need to wait for > * pending IO requests to complete or be queued for re-try. > * Thus the number queued (nr_queued) plus this request (1) > * must match the number of pending IOs (nr_pending) before > * we continue. > */ > spin_lock_irq(&conf->resync_lock); > conf->barrier++; > conf->nr_waiting++; > wait_event_lock_irq(conf->wait_barrier, > conf->nr_pending == conf->nr_queued+1, > conf->resync_lock, > ({ flush_pending_writes(conf); > raid1_unplug(conf->mddev->queue); })); > spin_unlock_irq(&conf->resync_lock); >} >static void unfreeze_array(conf_t *conf) >{ > /* reverse the effect of the freeze */ > spin_lock_irq(&conf->resync_lock); > conf->barrier--; > conf->nr_waiting--; > wake_up(&conf->wait_barrier); > spin_unlock_irq(&conf->resync_lock); >} > > >/* duplicate the data pages for behind I/O > * We return a list of bio_vec rather than just page pointers > * as it makes freeing easier > */ >static struct bio_vec *alloc_behind_pages(struct bio *bio) >{ > int i; > struct bio_vec *bvec; > struct bio_vec *pages = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), > GFP_NOIO); > if (unlikely(!pages)) > goto do_sync_io; > > bio_for_each_segment(bvec, bio, i) { > pages[i].bv_page = alloc_page(GFP_NOIO); > if (unlikely(!pages[i].bv_page)) > goto do_sync_io; > memcpy(kmap(pages[i].bv_page) + bvec->bv_offset, > kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); > kunmap(pages[i].bv_page); > kunmap(bvec->bv_page); > } > > return pages; > >do_sync_io: > if (pages) > for (i = 0; i < bio->bi_vcnt && pages[i].bv_page; i++) > put_page(pages[i].bv_page); > kfree(pages); > PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); > return NULL; >} > >static int make_request(mddev_t *mddev, struct bio * bio) >{ > conf_t *conf = mddev->private; > mirror_info_t *mirror; > r1bio_t *r1_bio; > struct bio *read_bio; > int i, targets = 0, disks; > struct bitmap *bitmap; > unsigned long flags; > struct bio_vec *behind_pages = NULL; > const int rw = bio_data_dir(bio); > const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); > const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA)); > mdk_rdev_t *blocked_rdev; > > /* > * Register the new request and wait if the reconstruction > * thread has put up a bar for new requests. > * Continue immediately if no resync is active currently. > */ > > md_write_start(mddev, bio); /* wait on superblock update early */ > > if (bio_data_dir(bio) == WRITE && > bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo && > bio->bi_sector < mddev->suspend_hi) { > /* As the suspend_* range is controlled by > * userspace, we want an interruptible > * wait. > */ > DEFINE_WAIT(w); > for (;;) { > flush_signals(current); > prepare_to_wait(&conf->wait_barrier, > &w, TASK_INTERRUPTIBLE); > if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo || > bio->bi_sector >= mddev->suspend_hi) > break; > schedule(); > } > finish_wait(&conf->wait_barrier, &w); > } > > wait_barrier(conf); > > bitmap = mddev->bitmap; > > /* > * make_request() can abort the operation when READA is being > * used and no empty request is available. > * > */ > r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); > > r1_bio->master_bio = bio; > r1_bio->sectors = bio->bi_size >> 9; > r1_bio->state = 0; > r1_bio->mddev = mddev; > r1_bio->sector = bio->bi_sector; > > if (rw == READ) { > /* > * read balancing logic: > */ > int rdisk = read_balance(conf, r1_bio); > > if (rdisk < 0) { > /* couldn't find anywhere to read from */ > raid_end_bio_io(r1_bio); > return 0; > } > mirror = conf->mirrors + rdisk; > > if (test_bit(WriteMostly, &mirror->rdev->flags) && > bitmap) { > /* Reading from a write-mostly device must > * take care not to over-take any writes > * that are 'behind' > */ > wait_event(bitmap->behind_wait, > atomic_read(&bitmap->behind_writes) == 0); > } > r1_bio->read_disk = rdisk; > > read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); > > r1_bio->bios[rdisk] = read_bio; > > read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; > read_bio->bi_bdev = mirror->rdev->bdev; > read_bio->bi_end_io = raid1_end_read_request; > read_bio->bi_rw = READ | do_sync; > read_bio->bi_private = r1_bio; > > generic_make_request(read_bio); > return 0; > } > > /* > * WRITE: > */ > /* first select target devices under spinlock and > * inc refcount on their rdev. Record them by setting > * bios[x] to bio > */ > disks = conf->raid_disks; > retry_write: > blocked_rdev = NULL; > rcu_read_lock(); > for (i = 0; i < disks; i++) { > mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); > if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { > atomic_inc(&rdev->nr_pending); > blocked_rdev = rdev; > break; > } > if (rdev && !test_bit(Faulty, &rdev->flags)) { > atomic_inc(&rdev->nr_pending); > if (test_bit(Faulty, &rdev->flags)) { > rdev_dec_pending(rdev, mddev); > r1_bio->bios[i] = NULL; > } else { > r1_bio->bios[i] = bio; > targets++; > } > } else > r1_bio->bios[i] = NULL; > } > rcu_read_unlock(); > > if (unlikely(blocked_rdev)) { > /* Wait for this device to become unblocked */ > int j; > > for (j = 0; j < i; j++) > if (r1_bio->bios[j]) > rdev_dec_pending(conf->mirrors[j].rdev, mddev); > > allow_barrier(conf); > md_wait_for_blocked_rdev(blocked_rdev, mddev); > wait_barrier(conf); > goto retry_write; > } > > BUG_ON(targets == 0); /* we never fail the last device */ > > if (targets < conf->raid_disks) { > /* array is degraded, we will not clear the bitmap > * on I/O completion (see raid1_end_write_request) */ > set_bit(R1BIO_Degraded, &r1_bio->state); > } > > /* do behind I/O ? > * Not if there are too many, or cannot allocate memory, > * or a reader on WriteMostly is waiting for behind writes > * to flush */ > if (bitmap && > (atomic_read(&bitmap->behind_writes) > < mddev->bitmap_info.max_write_behind) && > !waitqueue_active(&bitmap->behind_wait) && > (behind_pages = alloc_behind_pages(bio)) != NULL) > set_bit(R1BIO_BehindIO, &r1_bio->state); > > atomic_set(&r1_bio->remaining, 1); > atomic_set(&r1_bio->behind_remaining, 0); > > bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors, > test_bit(R1BIO_BehindIO, &r1_bio->state)); > for (i = 0; i < disks; i++) { > struct bio *mbio; > if (!r1_bio->bios[i]) > continue; > > mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); > r1_bio->bios[i] = mbio; > > mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; > mbio->bi_bdev = conf->mirrors[i].rdev->bdev; > mbio->bi_end_io = raid1_end_write_request; > mbio->bi_rw = WRITE | do_flush_fua | do_sync; > mbio->bi_private = r1_bio; > > if (behind_pages) { > struct bio_vec *bvec; > int j; > > /* Yes, I really want the '__' version so that > * we clear any unused pointer in the io_vec, rather > * than leave them unchanged. This is important > * because when we come to free the pages, we won't > * know the original bi_idx, so we just free > * them all > */ > __bio_for_each_segment(bvec, mbio, j, 0) > bvec->bv_page = behind_pages[j].bv_page; > if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) > atomic_inc(&r1_bio->behind_remaining); > } > > atomic_inc(&r1_bio->remaining); > spin_lock_irqsave(&conf->device_lock, flags); > bio_list_add(&conf->pending_bio_list, mbio); > blk_plug_device(mddev->queue); > spin_unlock_irqrestore(&conf->device_lock, flags); > } > r1_bio_write_done(r1_bio, bio->bi_vcnt, behind_pages, behind_pages != NULL); > kfree(behind_pages); /* the behind pages are attached to the bios now */ > > /* In case raid1d snuck in to freeze_array */ > wake_up(&conf->wait_barrier); > > if (do_sync) > md_wakeup_thread(mddev->thread); > > return 0; >} > >static void status(struct seq_file *seq, mddev_t *mddev) >{ > conf_t *conf = mddev->private; > int i; > > seq_printf(seq, " [%d/%d] [", conf->raid_disks, > conf->raid_disks - mddev->degraded); > rcu_read_lock(); > for (i = 0; i < conf->raid_disks; i++) { > mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); > seq_printf(seq, "%s", > rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); > } > rcu_read_unlock(); > seq_printf(seq, "]"); >} > > >static void error(mddev_t *mddev, mdk_rdev_t *rdev) >{ > char b[BDEVNAME_SIZE]; > conf_t *conf = mddev->private; > > > /* > * If it is not operational, then we have already marked it as dead > * else if it is the last working disks, ignore the error, let the > * next level up know. > * else mark the drive as failed > */ > if (test_bit(In_sync, &rdev->flags) > && (conf->raid_disks - mddev->degraded) == 1) { > /* > * Don't fail the drive, act as though we were just a > * normal single drive. > * However don't try a recovery from this drive as > * it is very likely to fail. > */ > mddev->recovery_disabled = 1; > return; > } > if (test_and_clear_bit(In_sync, &rdev->flags)) { > unsigned long flags; > spin_lock_irqsave(&conf->device_lock, flags); > mddev->degraded++; > set_bit(Faulty, &rdev->flags); > spin_unlock_irqrestore(&conf->device_lock, flags); > /* > * if recovery is running, make sure it aborts. > */ > set_bit(MD_RECOVERY_INTR, &mddev->recovery); > } else > set_bit(Faulty, &rdev->flags); > set_bit(MD_CHANGE_DEVS, &mddev->flags); > printk(KERN_ALERT "md/raid1:%s: Disk failure on %s, disabling device.\n" > KERN_ALERT "md/raid1:%s: Operation continuing on %d devices.\n", > mdname(mddev), bdevname(rdev->bdev, b), > mdname(mddev), conf->raid_disks - mddev->degraded); >} > >static void print_conf(conf_t *conf) >{ > int i; > > printk(KERN_DEBUG "RAID1 conf printout:\n"); > if (!conf) { > printk(KERN_DEBUG "(!conf)\n"); > return; > } > printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, > conf->raid_disks); > > rcu_read_lock(); > for (i = 0; i < conf->raid_disks; i++) { > char b[BDEVNAME_SIZE]; > mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); > if (rdev) > printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", > i, !test_bit(In_sync, &rdev->flags), > !test_bit(Faulty, &rdev->flags), > bdevname(rdev->bdev,b)); > } > rcu_read_unlock(); >} > >static void close_sync(conf_t *conf) >{ > wait_barrier(conf); > allow_barrier(conf); > > mempool_destroy(conf->r1buf_pool); > conf->r1buf_pool = NULL; >} > >static int raid1_spare_active(mddev_t *mddev) >{ > int i; > conf_t *conf = mddev->private; > int count = 0; > unsigned long flags; > > /* > * Find all failed disks within the RAID1 configuration > * and mark them readable. > * Called under mddev lock, so rcu protection not needed. > */ > for (i = 0; i < conf->raid_disks; i++) { > mdk_rdev_t *rdev = conf->mirrors[i].rdev; > if (rdev > && !test_bit(Faulty, &rdev->flags) > && !test_and_set_bit(In_sync, &rdev->flags)) { > count++; > sysfs_notify_dirent(rdev->sysfs_state); > } > } > spin_lock_irqsave(&conf->device_lock, flags); > mddev->degraded -= count; > spin_unlock_irqrestore(&conf->device_lock, flags); > > print_conf(conf); > return count; >} > > >static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) >{ > conf_t *conf = mddev->private; > int err = -EEXIST; > int mirror = 0; > mirror_info_t *p; > int first = 0; > int last = mddev->raid_disks - 1; > > if (rdev->raid_disk >= 0) > first = last = rdev->raid_disk; > > for (mirror = first; mirror <= last; mirror++) > if ( !(p=conf->mirrors+mirror)->rdev) { > > disk_stack_limits(mddev->gendisk, rdev->bdev, > rdev->data_offset << 9); > /* as we don't honour merge_bvec_fn, we must > * never risk violating it, so limit > * ->max_segments to one lying with a single > * page, as a one page request is never in > * violation. > */ > if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { > blk_queue_max_segments(mddev->queue, 1); > blk_queue_segment_boundary(mddev->queue, > PAGE_CACHE_SIZE - 1); > } > > p->head_position = 0; > rdev->raid_disk = mirror; > err = 0; > /* As all devices are equivalent, we don't need a full recovery > * if this was recently any drive of the array > */ > if (rdev->saved_raid_disk < 0) > conf->fullsync = 1; > rcu_assign_pointer(p->rdev, rdev); > break; > } > md_integrity_add_rdev(rdev, mddev); > print_conf(conf); > return err; >} > >static int raid1_remove_disk(mddev_t *mddev, int number) >{ > conf_t *conf = mddev->private; > int err = 0; > mdk_rdev_t *rdev; > mirror_info_t *p = conf->mirrors+ number; > > print_conf(conf); > rdev = p->rdev; > if (rdev) { > if (test_bit(In_sync, &rdev->flags) || > atomic_read(&rdev->nr_pending)) { > err = -EBUSY; > goto abort; > } > /* Only remove non-faulty devices if recovery > * is not possible. > */ > if (!test_bit(Faulty, &rdev->flags) && > !mddev->recovery_disabled && > mddev->degraded < conf->raid_disks) { > err = -EBUSY; > goto abort; > } > p->rdev = NULL; > synchronize_rcu(); > if (atomic_read(&rdev->nr_pending)) { > /* lost the race, try later */ > err = -EBUSY; > p->rdev = rdev; > goto abort; > } > md_integrity_register(mddev); > } >abort: > > print_conf(conf); > return err; >} > > >static void end_sync_read(struct bio *bio, int error) >{ > r1bio_t *r1_bio = bio->bi_private; > int i; > > for (i=r1_bio->mddev->raid_disks; i--; ) > if (r1_bio->bios[i] == bio) > break; > BUG_ON(i < 0); > update_head_pos(i, r1_bio); > /* > * we have read a block, now it needs to be re-written, > * or re-read if the read failed. > * We don't do much here, just schedule handling by raid1d > */ > if (test_bit(BIO_UPTODATE, &bio->bi_flags)) > set_bit(R1BIO_Uptodate, &r1_bio->state); > > if (atomic_dec_and_test(&r1_bio->remaining)) > reschedule_retry(r1_bio); >} > >static void end_sync_write(struct bio *bio, int error) >{ > int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); > r1bio_t *r1_bio = bio->bi_private; > mddev_t *mddev = r1_bio->mddev; > conf_t *conf = mddev->private; > int i; > int mirror=0; > > for (i = 0; i < conf->raid_disks; i++) > if (r1_bio->bios[i] == bio) { > mirror = i; > break; > } > if (!uptodate) { > sector_t sync_blocks = 0; > sector_t s = r1_bio->sector; > long sectors_to_go = r1_bio->sectors; > /* make sure these bits doesn't get cleared. */ > do { > bitmap_end_sync(mddev->bitmap, s, > &sync_blocks, 1); > s += sync_blocks; > sectors_to_go -= sync_blocks; > } while (sectors_to_go > 0); > md_error(mddev, conf->mirrors[mirror].rdev); > } > > update_head_pos(mirror, r1_bio); > > if (atomic_dec_and_test(&r1_bio->remaining)) { > sector_t s = r1_bio->sectors; > put_buf(r1_bio); > md_done_sync(mddev, s, uptodate); > } >} > >static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) >{ > conf_t *conf = mddev->private; > int i; > int disks = conf->raid_disks; > struct bio *bio, *wbio; > > bio = r1_bio->bios[r1_bio->read_disk]; > > > if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { > /* We have read all readable devices. If we haven't > * got the block, then there is no hope left. > * If we have, then we want to do a comparison > * and skip the write if everything is the same. > * If any blocks failed to read, then we need to > * attempt an over-write > */ > int primary; > if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { > for (i=0; i<mddev->raid_disks; i++) > if (r1_bio->bios[i]->bi_end_io == end_sync_read) > md_error(mddev, conf->mirrors[i].rdev); > > md_done_sync(mddev, r1_bio->sectors, 1); > put_buf(r1_bio); > return; > } > for (primary=0; primary<mddev->raid_disks; primary++) > if (r1_bio->bios[primary]->bi_end_io == end_sync_read && > test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { > r1_bio->bios[primary]->bi_end_io = NULL; > rdev_dec_pending(conf->mirrors[primary].rdev, mddev); > break; > } > r1_bio->read_disk = primary; > for (i=0; i<mddev->raid_disks; i++) > if (r1_bio->bios[i]->bi_end_io == end_sync_read) { > int j; > int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9); > struct bio *pbio = r1_bio->bios[primary]; > struct bio *sbio = r1_bio->bios[i]; > > if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { > for (j = vcnt; j-- ; ) { > struct page *p, *s; > p = pbio->bi_io_vec[j].bv_page; > s = sbio->bi_io_vec[j].bv_page; > if (memcmp(page_address(p), > page_address(s), > PAGE_SIZE)) > break; > } > } else > j = 0; > if (j >= 0) > mddev->resync_mismatches += r1_bio->sectors; > if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) > && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { > sbio->bi_end_io = NULL; > rdev_dec_pending(conf->mirrors[i].rdev, mddev); > } else { > /* fixup the bio for reuse */ > int size; > sbio->bi_vcnt = vcnt; > sbio->bi_size = r1_bio->sectors << 9; > sbio->bi_idx = 0; > sbio->bi_phys_segments = 0; > sbio->bi_flags &= ~(BIO_POOL_MASK - 1); > sbio->bi_flags |= 1 << BIO_UPTODATE; > sbio->bi_next = NULL; > sbio->bi_sector = r1_bio->sector + > conf->mirrors[i].rdev->data_offset; > sbio->bi_bdev = conf->mirrors[i].rdev->bdev; > size = sbio->bi_size; > for (j = 0; j < vcnt ; j++) { > struct bio_vec *bi; > bi = &sbio->bi_io_vec[j]; > bi->bv_offset = 0; > if (size > PAGE_SIZE) > bi->bv_len = PAGE_SIZE; > else > bi->bv_len = size; > size -= PAGE_SIZE; > memcpy(page_address(bi->bv_page), > page_address(pbio->bi_io_vec[j].bv_page), > PAGE_SIZE); > } > > } > } > } > if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { > /* ouch - failed to read all of that. > * Try some synchronous reads of other devices to get > * good data, much like with normal read errors. Only > * read into the pages we already have so we don't > * need to re-issue the read request. > * We don't need to freeze the array, because being in an > * active sync request, there is no normal IO, and > * no overlapping syncs. > */ > sector_t sect = r1_bio->sector; > int sectors = r1_bio->sectors; > int idx = 0; > > while(sectors) { > int s = sectors; > int d = r1_bio->read_disk; > int success = 0; > mdk_rdev_t *rdev; > > if (s > (PAGE_SIZE>>9)) > s = PAGE_SIZE >> 9; > do { > if (r1_bio->bios[d]->bi_end_io == end_sync_read) { > /* No rcu protection needed here devices > * can only be removed when no resync is > * active, and resync is currently active > */ > rdev = conf->mirrors[d].rdev; > if (sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, > bio->bi_io_vec[idx].bv_page, > READ)) { > success = 1; > break; > } > } > d++; > if (d == conf->raid_disks) > d = 0; > } while (!success && d != r1_bio->read_disk); > > if (success) { > int start = d; > /* write it back and re-read */ > set_bit(R1BIO_Uptodate, &r1_bio->state); > while (d != r1_bio->read_disk) { > if (d == 0) > d = conf->raid_disks; > d--; > if (r1_bio->bios[d]->bi_end_io != end_sync_read) > continue; > rdev = conf->mirrors[d].rdev; > atomic_add(s, &rdev->corrected_errors); > if (sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, > bio->bi_io_vec[idx].bv_page, > WRITE) == 0) > md_error(mddev, rdev); > } > d = start; > while (d != r1_bio->read_disk) { > if (d == 0) > d = conf->raid_disks; > d--; > if (r1_bio->bios[d]->bi_end_io != end_sync_read) > continue; > rdev = conf->mirrors[d].rdev; > if (sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, > bio->bi_io_vec[idx].bv_page, > READ) == 0) > md_error(mddev, rdev); > } > } else { > char b[BDEVNAME_SIZE]; > /* Cannot read from anywhere, array is toast */ > md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); > printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error" > " for block %llu\n", > mdname(mddev), > bdevname(bio->bi_bdev, b), > (unsigned long long)r1_bio->sector); > md_done_sync(mddev, r1_bio->sectors, 0); > put_buf(r1_bio); > return; > } > sectors -= s; > sect += s; > idx ++; > } > } > > /* > * schedule writes > */ > atomic_set(&r1_bio->remaining, 1); > for (i = 0; i < disks ; i++) { > wbio = r1_bio->bios[i]; > if (wbio->bi_end_io == NULL || > (wbio->bi_end_io == end_sync_read && > (i == r1_bio->read_disk || > !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) > continue; > > wbio->bi_rw = WRITE; > wbio->bi_end_io = end_sync_write; > atomic_inc(&r1_bio->remaining); > md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); > > generic_make_request(wbio); > } > > if (atomic_dec_and_test(&r1_bio->remaining)) { > /* if we're here, all write(s) have completed, so clean up */ > md_done_sync(mddev, r1_bio->sectors, 1); > put_buf(r1_bio); > } >} > >/* > * This is a kernel thread which: > * > * 1. Retries failed read operations on working mirrors. > * 2. Updates the raid superblock when problems encounter. > * 3. Performs writes following reads for array syncronising. > */ > >static void fix_read_error(conf_t *conf, int read_disk, > sector_t sect, int sectors) >{ > mddev_t *mddev = conf->mddev; > while(sectors) { > int s = sectors; > int d = read_disk; > int success = 0; > int start; > mdk_rdev_t *rdev; > > if (s > (PAGE_SIZE>>9)) > s = PAGE_SIZE >> 9; > > do { > /* Note: no rcu protection needed here > * as this is synchronous in the raid1d thread > * which is the thread that might remove > * a device. If raid1d ever becomes multi-threaded.... > */ > rdev = conf->mirrors[d].rdev; > if (rdev && > test_bit(In_sync, &rdev->flags) && > sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, > conf->tmppage, READ)) > success = 1; > else { > d++; > if (d == conf->raid_disks) > d = 0; > } > } while (!success && d != read_disk); > > if (!success) { > /* Cannot read from anywhere -- bye bye array */ > md_error(mddev, conf->mirrors[read_disk].rdev); > break; > } > /* write it back and re-read */ > start = d; > while (d != read_disk) { > if (d==0) > d = conf->raid_disks; > d--; > rdev = conf->mirrors[d].rdev; > if (rdev && > test_bit(In_sync, &rdev->flags)) { > if (sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, conf->tmppage, WRITE) > == 0) > /* Well, this device is dead */ > md_error(mddev, rdev); > } > } > d = start; > while (d != read_disk) { > char b[BDEVNAME_SIZE]; > if (d==0) > d = conf->raid_disks; > d--; > rdev = conf->mirrors[d].rdev; > if (rdev && > test_bit(In_sync, &rdev->flags)) { > if (sync_page_io(rdev, > sect + rdev->data_offset, > s<<9, conf->tmppage, READ) > == 0) > /* Well, this device is dead */ > md_error(mddev, rdev); > else { > atomic_add(s, &rdev->corrected_errors); > printk(KERN_INFO > "md/raid1:%s: read error corrected " > "(%d sectors at %llu on %s)\n", > mdname(mddev), s, > (unsigned long long)(sect + > rdev->data_offset), > bdevname(rdev->bdev, b)); > } > } > } > sectors -= s; > sect += s; > } >} > >static void raid1d(mddev_t *mddev) >{ > r1bio_t *r1_bio; > struct bio *bio; > unsigned long flags; > conf_t *conf = mddev->private; > struct list_head *head = &conf->retry_list; > int unplug=0; > mdk_rdev_t *rdev; > > md_check_recovery(mddev); > > for (;;) { > char b[BDEVNAME_SIZE]; > > unplug += flush_pending_writes(conf); > > spin_lock_irqsave(&conf->device_lock, flags); > if (list_empty(head)) { > spin_unlock_irqrestore(&conf->device_lock, flags); > break; > } > r1_bio = list_entry(head->prev, r1bio_t, retry_list); > list_del(head->prev); > conf->nr_queued--; > spin_unlock_irqrestore(&conf->device_lock, flags); > > mddev = r1_bio->mddev; > conf = mddev->private; > if (test_bit(R1BIO_IsSync, &r1_bio->state)) { > sync_request_write(mddev, r1_bio); > unplug = 1; > } else { > int disk; > > /* we got a read error. Maybe the drive is bad. Maybe just > * the block and we can fix it. > * We freeze all other IO, and try reading the block from > * other devices. When we find one, we re-write > * and check it that fixes the read error. > * This is all done synchronously while the array is > * frozen > */ > if (mddev->ro == 0) { > freeze_array(conf); > fix_read_error(conf, r1_bio->read_disk, > r1_bio->sector, > r1_bio->sectors); > unfreeze_array(conf); > } else > md_error(mddev, > conf->mirrors[r1_bio->read_disk].rdev); > > bio = r1_bio->bios[r1_bio->read_disk]; > if ((disk=read_balance(conf, r1_bio)) == -1) { > printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" > " read error for block %llu\n", > mdname(mddev), > bdevname(bio->bi_bdev,b), > (unsigned long long)r1_bio->sector); > raid_end_bio_io(r1_bio); > } else { > const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC; > r1_bio->bios[r1_bio->read_disk] = > mddev->ro ? IO_BLOCKED : NULL; > r1_bio->read_disk = disk; > bio_put(bio); > bio = bio_clone_mddev(r1_bio->master_bio, > GFP_NOIO, mddev); > r1_bio->bios[r1_bio->read_disk] = bio; > rdev = conf->mirrors[disk].rdev; > if (printk_ratelimit()) > printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to" > " other mirror: %s\n", > mdname(mddev), > (unsigned long long)r1_bio->sector, > bdevname(rdev->bdev,b)); > bio->bi_sector = r1_bio->sector + rdev->data_offset; > bio->bi_bdev = rdev->bdev; > bio->bi_end_io = raid1_end_read_request; > bio->bi_rw = READ | do_sync; > bio->bi_private = r1_bio; > unplug = 1; > generic_make_request(bio); > } > } > cond_resched(); > } > if (unplug) > unplug_slaves(mddev); >} > > >static int init_resync(conf_t *conf) >{ > int buffs; > > buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; > BUG_ON(conf->r1buf_pool); > conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, > conf->poolinfo); > if (!conf->r1buf_pool) > return -ENOMEM; > conf->next_resync = 0; > return 0; >} > >/* > * perform a "sync" on one "block" > * > * We need to make sure that no normal I/O request - particularly write > * requests - conflict with active sync requests. > * > * This is achieved by tracking pending requests and a 'barrier' concept > * that can be installed to exclude normal IO requests. > */ > >static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) >{ > conf_t *conf = mddev->private; > r1bio_t *r1_bio; > struct bio *bio; > sector_t max_sector, nr_sectors; > int disk = -1; > int i; > int wonly = -1; > int write_targets = 0, read_targets = 0; > sector_t sync_blocks; > int still_degraded = 0; > > if (!conf->r1buf_pool) > if (init_resync(conf)) > return 0; > > max_sector = mddev->dev_sectors; > if (sector_nr >= max_sector) { > /* If we aborted, we need to abort the > * sync on the 'current' bitmap chunk (there will > * only be one in raid1 resync. > * We can find the current addess in mddev->curr_resync > */ > if (mddev->curr_resync < max_sector) /* aborted */ > bitmap_end_sync(mddev->bitmap, mddev->curr_resync, > &sync_blocks, 1); > else /* completed sync */ > conf->fullsync = 0; > > bitmap_close_sync(mddev->bitmap); > close_sync(conf); > return 0; > } > > if (mddev->bitmap == NULL && > mddev->recovery_cp == MaxSector && > !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && > conf->fullsync == 0) { > *skipped = 1; > return max_sector - sector_nr; > } > /* before building a request, check if we can skip these blocks.. > * This call the bitmap_start_sync doesn't actually record anything > */ > if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && > !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { > /* We can skip this block, and probably several more */ > *skipped = 1; > return sync_blocks; > } > /* > * If there is non-resync activity waiting for a turn, > * and resync is going fast enough, > * then let it though before starting on this new sync request. > */ > if (!go_faster && conf->nr_waiting) > msleep_interruptible(1000); > > bitmap_cond_end_sync(mddev->bitmap, sector_nr); > r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); > raise_barrier(conf); > > conf->next_resync = sector_nr; > > rcu_read_lock(); > /* > * If we get a correctably read error during resync or recovery, > * we might want to read from a different device. So we > * flag all drives that could conceivably be read from for READ, > * and any others (which will be non-In_sync devices) for WRITE. > * If a read fails, we try reading from something else for which READ > * is OK. > */ > > r1_bio->mddev = mddev; > r1_bio->sector = sector_nr; > r1_bio->state = 0; > set_bit(R1BIO_IsSync, &r1_bio->state); > > for (i=0; i < conf->raid_disks; i++) { > mdk_rdev_t *rdev; > bio = r1_bio->bios[i]; > > /* take from bio_init */ > bio->bi_next = NULL; > bio->bi_flags &= ~(BIO_POOL_MASK-1); > bio->bi_flags |= 1 << BIO_UPTODATE; > bio->bi_comp_cpu = -1; > bio->bi_rw = READ; > bio->bi_vcnt = 0; > bio->bi_idx = 0; > bio->bi_phys_segments = 0; > bio->bi_size = 0; > bio->bi_end_io = NULL; > bio->bi_private = NULL; > > rdev = rcu_dereference(conf->mirrors[i].rdev); > if (rdev == NULL || > test_bit(Faulty, &rdev->flags)) { > still_degraded = 1; > continue; > } else if (!test_bit(In_sync, &rdev->flags)) { > bio->bi_rw = WRITE; > bio->bi_end_io = end_sync_write; > write_targets ++; > } else { > /* may need to read from here */ > bio->bi_rw = READ; > bio->bi_end_io = end_sync_read; > if (test_bit(WriteMostly, &rdev->flags)) { > if (wonly < 0) > wonly = i; > } else { > if (disk < 0) > disk = i; > } > read_targets++; > } > atomic_inc(&rdev->nr_pending); > bio->bi_sector = sector_nr + rdev->data_offset; > bio->bi_bdev = rdev->bdev; > bio->bi_private = r1_bio; > } > rcu_read_unlock(); > if (disk < 0) > disk = wonly; > r1_bio->read_disk = disk; > > if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) > /* extra read targets are also write targets */ > write_targets += read_targets-1; > > if (write_targets == 0 || read_targets == 0) { > /* There is nowhere to write, so all non-sync > * drives must be failed - so we are finished > */ > sector_t rv = max_sector - sector_nr; > *skipped = 1; > put_buf(r1_bio); > return rv; > } > > if (max_sector > mddev->resync_max) > max_sector = mddev->resync_max; /* Don't do IO beyond here */ > nr_sectors = 0; > sync_blocks = 0; > do { > struct page *page; > int len = PAGE_SIZE; > if (sector_nr + (len>>9) > max_sector) > len = (max_sector - sector_nr) << 9; > if (len == 0) > break; > if (sync_blocks == 0) { > if (!bitmap_start_sync(mddev->bitmap, sector_nr, > &sync_blocks, still_degraded) && > !conf->fullsync && > !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) > break; > BUG_ON(sync_blocks < (PAGE_SIZE>>9)); > if ((len >> 9) > sync_blocks) > len = sync_blocks<<9; > } > > for (i=0 ; i < conf->raid_disks; i++) { > bio = r1_bio->bios[i]; > if (bio->bi_end_io) { > page = bio->bi_io_vec[bio->bi_vcnt].bv_page; > if (bio_add_page(bio, page, len, 0) == 0) { > /* stop here */ > bio->bi_io_vec[bio->bi_vcnt].bv_page = page; > while (i > 0) { > i--; > bio = r1_bio->bios[i]; > if (bio->bi_end_io==NULL) > continue; > /* remove last page from this bio */ > bio->bi_vcnt--; > bio->bi_size -= len; > bio->bi_flags &= ~(1<< BIO_SEG_VALID); > } > goto bio_full; > } > } > } > nr_sectors += len>>9; > sector_nr += len>>9; > sync_blocks -= (len>>9); > } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); > bio_full: > r1_bio->sectors = nr_sectors; > > /* For a user-requested sync, we read all readable devices and do a > * compare > */ > if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { > atomic_set(&r1_bio->remaining, read_targets); > for (i=0; i<conf->raid_disks; i++) { > bio = r1_bio->bios[i]; > if (bio->bi_end_io == end_sync_read) { > md_sync_acct(bio->bi_bdev, nr_sectors); > generic_make_request(bio); > } > } > } else { > atomic_set(&r1_bio->remaining, 1); > bio = r1_bio->bios[r1_bio->read_disk]; > md_sync_acct(bio->bi_bdev, nr_sectors); > generic_make_request(bio); > > } > return nr_sectors; >} > >static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks) >{ > if (sectors) > return sectors; > > return mddev->dev_sectors; >} > >static conf_t *setup_conf(mddev_t *mddev) >{ > conf_t *conf; > int i; > mirror_info_t *disk; > mdk_rdev_t *rdev; > int err = -ENOMEM; > > conf = kzalloc(sizeof(conf_t), GFP_KERNEL); > if (!conf) > goto abort; > > conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, > GFP_KERNEL); > if (!conf->mirrors) > goto abort; > > conf->tmppage = alloc_page(GFP_KERNEL); > if (!conf->tmppage) > goto abort; > > conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); > if (!conf->poolinfo) > goto abort; > conf->poolinfo->raid_disks = mddev->raid_disks; > conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, > r1bio_pool_free, > conf->poolinfo); > if (!conf->r1bio_pool) > goto abort; > > conf->poolinfo->mddev = mddev; > > spin_lock_init(&conf->device_lock); > list_for_each_entry(rdev, &mddev->disks, same_set) { > int disk_idx = rdev->raid_disk; > if (disk_idx >= mddev->raid_disks > || disk_idx < 0) > continue; > disk = conf->mirrors + disk_idx; > > disk->rdev = rdev; > > disk->head_position = 0; > } > conf->raid_disks = mddev->raid_disks; > conf->mddev = mddev; > INIT_LIST_HEAD(&conf->retry_list); > > spin_lock_init(&conf->resync_lock); > init_waitqueue_head(&conf->wait_barrier); > > bio_list_init(&conf->pending_bio_list); > > conf->last_used = -1; > for (i = 0; i < conf->raid_disks; i++) { > > disk = conf->mirrors + i; > > if (!disk->rdev || > !test_bit(In_sync, &disk->rdev->flags)) { > disk->head_position = 0; > if (disk->rdev) > conf->fullsync = 1; > } else if (conf->last_used < 0) > /* > * The first working device is used as a > * starting point to read balancing. > */ > conf->last_used = i; > } > > err = -EIO; > if (conf->last_used < 0) { > printk(KERN_ERR "md/raid1:%s: no operational mirrors\n", > mdname(mddev)); > goto abort; > } > err = -ENOMEM; > conf->thread = md_register_thread(raid1d, mddev, NULL); > if (!conf->thread) { > printk(KERN_ERR > "md/raid1:%s: couldn't allocate thread\n", > mdname(mddev)); > goto abort; > } > > return conf; > > abort: > if (conf) { > if (conf->r1bio_pool) > mempool_destroy(conf->r1bio_pool); > kfree(conf->mirrors); > safe_put_page(conf->tmppage); > kfree(conf->poolinfo); > kfree(conf); > } > return ERR_PTR(err); >} > >static int run(mddev_t *mddev) >{ > conf_t *conf; > int i; > mdk_rdev_t *rdev; > > if (mddev->level != 1) { > printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n", > mdname(mddev), mddev->level); > return -EIO; > } > if (mddev->reshape_position != MaxSector) { > printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n", > mdname(mddev)); > return -EIO; > } > /* > * copy the already verified devices into our private RAID1 > * bookkeeping area. [whatever we allocate in run(), > * should be freed in stop()] > */ > if (mddev->private == NULL) > conf = setup_conf(mddev); > else > conf = mddev->private; > > if (IS_ERR(conf)) > return PTR_ERR(conf); > > mddev->queue->queue_lock = &conf->device_lock; > list_for_each_entry(rdev, &mddev->disks, same_set) { > disk_stack_limits(mddev->gendisk, rdev->bdev, > rdev->data_offset << 9); > /* as we don't honour merge_bvec_fn, we must never risk > * violating it, so limit ->max_segments to 1 lying within > * a single page, as a one page request is never in violation. > */ > if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { > blk_queue_max_segments(mddev->queue, 1); > blk_queue_segment_boundary(mddev->queue, > PAGE_CACHE_SIZE - 1); > } > } > > mddev->degraded = 0; > for (i=0; i < conf->raid_disks; i++) > if (conf->mirrors[i].rdev == NULL || > !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || > test_bit(Faulty, &conf->mirrors[i].rdev->flags)) > mddev->degraded++; > > if (conf->raid_disks - mddev->degraded == 1) > mddev->recovery_cp = MaxSector; > > if (mddev->recovery_cp != MaxSector) > printk(KERN_NOTICE "md/raid1:%s: not clean" > " -- starting background reconstruction\n", > mdname(mddev)); > printk(KERN_INFO > "md/raid1:%s: active with %d out of %d mirrors\n", > mdname(mddev), mddev->raid_disks - mddev->degraded, > mddev->raid_disks); > > /* > * Ok, everything is just fine now > */ > mddev->thread = conf->thread; > conf->thread = NULL; > > /* start read balance using near head, no time configured, no stripe shift configured too */ > conf->read_balance_mode=0; > conf->read_balance_stripe_shift=0; > > mddev->private = conf; > > md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); > if (mddev->to_remove == &raid1_attrs_group){ > /* remove sysfs read balance */ > mddev->to_remove = NULL; > }else{ > /* start sysfs read balance */ > if(sysfs_create_group(&mddev->kobj, &raid1_attrs_group)) > printk(KERN_WARNING > "md/raid1:%s: failed to create sysfs attributes.\n", > mdname(mddev)); > } > mddev->queue->unplug_fn = raid1_unplug; > mddev->queue->backing_dev_info.congested_fn = raid1_congested; > mddev->queue->backing_dev_info.congested_data = mddev; > md_integrity_register(mddev); > return 0; >} > >static int stop(mddev_t *mddev) >{ > conf_t *conf = mddev->private; > struct bitmap *bitmap = mddev->bitmap; > > /* wait for behind writes to complete */ > if (bitmap && atomic_read(&bitmap->behind_writes) > 0) { > printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n", > mdname(mddev)); > /* need to kick something here to make sure I/O goes? */ > wait_event(bitmap->behind_wait, > atomic_read(&bitmap->behind_writes) == 0); > } > > raise_barrier(conf); > lower_barrier(conf); > > md_unregister_thread(mddev->thread); > mddev->thread = NULL; > > /* read balance sysfs group */ > mddev->to_remove = &raid1_attrs_group; > > blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ > if (conf->r1bio_pool) > mempool_destroy(conf->r1bio_pool); > kfree(conf->mirrors); > kfree(conf->poolinfo); > kfree(conf); > mddev->private = NULL; > return 0; >} > >static int raid1_resize(mddev_t *mddev, sector_t sectors) >{ > /* no resync is happening, and there is enough space > * on all devices, so we can resize. > * We need to make sure resync covers any new space. > * If the array is shrinking we should possibly wait until > * any io in the removed space completes, but it hardly seems > * worth it. > */ > md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0)); > if (mddev->array_sectors > raid1_size(mddev, sectors, 0)) > return -EINVAL; > set_capacity(mddev->gendisk, mddev->array_sectors); > revalidate_disk(mddev->gendisk); > if (sectors > mddev->dev_sectors && > mddev->recovery_cp == MaxSector) { > mddev->recovery_cp = mddev->dev_sectors; > set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); > } > mddev->dev_sectors = sectors; > mddev->resync_max_sectors = sectors; > return 0; >} > >static int raid1_reshape(mddev_t *mddev) >{ > /* We need to: > * 1/ resize the r1bio_pool > * 2/ resize conf->mirrors > * > * We allocate a new r1bio_pool if we can. > * Then raise a device barrier and wait until all IO stops. > * Then resize conf->mirrors and swap in the new r1bio pool. > * > * At the same time, we "pack" the devices so that all the missing > * devices have the higher raid_disk numbers. > */ > mempool_t *newpool, *oldpool; > struct pool_info *newpoolinfo; > mirror_info_t *newmirrors; > conf_t *conf = mddev->private; > int cnt, raid_disks; > unsigned long flags; > int d, d2, err; > > /* Cannot change chunk_size, layout, or level */ > if (mddev->chunk_sectors != mddev->new_chunk_sectors || > mddev->layout != mddev->new_layout || > mddev->level != mddev->new_level) { > mddev->new_chunk_sectors = mddev->chunk_sectors; > mddev->new_layout = mddev->layout; > mddev->new_level = mddev->level; > return -EINVAL; > } > > err = md_allow_write(mddev); > if (err) > return err; > > raid_disks = mddev->raid_disks + mddev->delta_disks; > > if (raid_disks < conf->raid_disks) { > cnt=0; > for (d= 0; d < conf->raid_disks; d++) > if (conf->mirrors[d].rdev) > cnt++; > if (cnt > raid_disks) > return -EBUSY; > } > > newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); > if (!newpoolinfo) > return -ENOMEM; > newpoolinfo->mddev = mddev; > newpoolinfo->raid_disks = raid_disks; > > newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, > r1bio_pool_free, newpoolinfo); > if (!newpool) { > kfree(newpoolinfo); > return -ENOMEM; > } > newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL); > if (!newmirrors) { > kfree(newpoolinfo); > mempool_destroy(newpool); > return -ENOMEM; > } > > raise_barrier(conf); > > /* ok, everything is stopped */ > oldpool = conf->r1bio_pool; > conf->r1bio_pool = newpool; > > for (d = d2 = 0; d < conf->raid_disks; d++) { > mdk_rdev_t *rdev = conf->mirrors[d].rdev; > if (rdev && rdev->raid_disk != d2) { > char nm[20]; > sprintf(nm, "rd%d", rdev->raid_disk); > sysfs_remove_link(&mddev->kobj, nm); > rdev->raid_disk = d2; > sprintf(nm, "rd%d", rdev->raid_disk); > sysfs_remove_link(&mddev->kobj, nm); > if (sysfs_create_link(&mddev->kobj, > &rdev->kobj, nm)) > printk(KERN_WARNING > "md/raid1:%s: cannot register " > "%s\n", > mdname(mddev), nm); > } > if (rdev) > newmirrors[d2++].rdev = rdev; > } > kfree(conf->mirrors); > conf->mirrors = newmirrors; > kfree(conf->poolinfo); > conf->poolinfo = newpoolinfo; > > spin_lock_irqsave(&conf->device_lock, flags); > mddev->degraded += (raid_disks - conf->raid_disks); > spin_unlock_irqrestore(&conf->device_lock, flags); > conf->raid_disks = mddev->raid_disks = raid_disks; > mddev->delta_disks = 0; > > conf->last_used = 0; /* just make sure it is in-range */ > lower_barrier(conf); > > set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); > md_wakeup_thread(mddev->thread); > > mempool_destroy(oldpool); > return 0; >} > >static void raid1_quiesce(mddev_t *mddev, int state) >{ > conf_t *conf = mddev->private; > > switch(state) { > case 2: /* wake for suspend */ > wake_up(&conf->wait_barrier); > break; > case 1: > raise_barrier(conf); > break; > case 0: > lower_barrier(conf); > break; > } >} > >static void *raid1_takeover(mddev_t *mddev) >{ > /* raid1 can take over: > * raid5 with 2 devices, any layout or chunk size > */ > if (mddev->level == 5 && mddev->raid_disks == 2) { > conf_t *conf; > mddev->new_level = 1; > mddev->new_layout = 0; > mddev->new_chunk_sectors = 0; > conf = setup_conf(mddev); > if (!IS_ERR(conf)) > conf->barrier = 1; > return conf; > } > return ERR_PTR(-EINVAL); >} > >static struct mdk_personality raid1_personality = >{ > .name = "raid1", > .level = 1, > .owner = THIS_MODULE, > .make_request = make_request, > .run = run, > .stop = stop, > .status = status, > .error_handler = error, > .hot_add_disk = raid1_add_disk, > .hot_remove_disk= raid1_remove_disk, > .spare_active = raid1_spare_active, > .sync_request = sync_request, > .resize = raid1_resize, > .size = raid1_size, > .check_reshape = raid1_reshape, > .quiesce = raid1_quiesce, > .takeover = raid1_takeover, >}; > >static int __init raid_init(void) >{ > return register_md_personality(&raid1_personality); >} > >static void raid_exit(void) >{ > unregister_md_personality(&raid1_personality); >} > >module_init(raid_init); >module_exit(raid_exit); >MODULE_LICENSE("GPL"); >MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); >MODULE_ALIAS("md-personality-3"); /* RAID1 */ >MODULE_ALIAS("md-raid1"); >MODULE_ALIAS("md-level-1");
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