Hi, this is a feature patch that implements 'proactive raid5 disk replacement' (http://www.arctic.org/~dean/raid-wishlist.html), that could help a lot on large raid5 arrays built from cheap sata drivers when the IO traffic such large that daily media scan on the disks isn't possible. linux software raid is very fragile by default, the typical (nervous) breakdown situation is: I noticed a bad block on a drive, replace it, and the resync fails cause another 2-3 disks have hidden badblocks too. I've to save the disks and rebuild bad blocks with a userspace tool (by hand..), meanwhile the site is down for hours. bad; especially when a pair of simple steps enough to avoid from this atypical problem: 1. dont kick a drive on read error cause it is possible that 99.99% is useable and will help (to serve and to save data) if another drive show bad sectors in same array 2. let mirror a partially failed drive to a spare _online_ and replace the source of the mirror with the spare when it's done. bad blocks isn't a problem unless same sector damaged on two disks what's a rare case. in this way is possible to fix an array with partially failed drives without data loss and without downtime I'm not a programmer just a sysadm who admins a large software sata array, but my angry got bigger than my laziness, so I made this patch on this weekend.. I'm not understand every piece of the md code (eg. the if-forest of the handle_stripe :) yet, so this patch may be a bug-colony and wrong by design, but I've tested it under heavy stress with both of 'faulty' module and real disks, and it works fine! ideas, piece of advice, bugfix/enchancement is welcomed! (I know, raid6 could be another solution for this problem, but that's a large overhead.) use: 1. patch the kernel, this one is against 2.6.11 2. type: # make drives mdadm -B -n1 -l faulty /dev/md/1 /dev/rd/0 mdadm -B -n1 -l faulty /dev/md/2 /dev/rd/1 mdadm -B -n1 -l faulty /dev/md/3 /dev/rd/2 # make the array mdadm -C -n3 -l5 /dev/md/0 /dev/md/1 /dev/md/2 /dev/md/3 # .. wait for sync .. # grow bad blocks as ma*tor does mdadm --grow -l faulty -p rp454 /dev/md/1 mdadm --grow -l faulty -p rp738 /dev/md/2 # add a spare mdadm -a /dev/md/0 /dev/rd/4 # -> fail a drive, sync begins <- # the md/1 will not marked as failed, this is the point, but if you want to, # you can issue this command again! mdadm -f /dev/md/0 /dev/md/1 # kernel: # resync from md1 to spare ram4 # added spare for active resync # .. wonder the read errors from md[12] and the sync goes on! # feel free to stress the md at this time, mkfs, dd, badblocks, etc # kernel: # raid5_spare_active: 3 in_sync 3->0 # /proc/mdstat: # md0 : active raid5 ram4[0] md3[2] md2[1] md1[0] # -> ram4 and md1 have same id, this means the spare is a complete mirror, # if you stop the array you can assembly it with ram4 instead of md1, # the superblock same both of them # check the mirror (stop write stress if any) mdadm --grow -l faulty -p none /dev/md/1 cmp /dev/md/1 /dev/rd/4 # hot-replace the mirrored -partially failed- device with the active spare # (yes, mark it as failed again, but if there's a syncing- or synced 'active spare' # the -f really fails the device or replace it with the synced spare) mdadm -f /dev/md/0 /dev/md/1 # kernel: # replace md1 with in_sync active spare ram4 # and voila! # /proc/mdstat: # md0 : active raid5 ram4[0] md3[2] md2[1] .. I hope someone can use it for something, for me it's a musthave feature .. -- dap
this is a feature patch that implements 'proactive raid5 disk replacement' (http://www.arctic.org/~dean/raid-wishlist.html), that could help a lot on large raid5 arrays built from cheap sata drivers when the IO traffic such large that daily media scan on the disks isn't possible. linux software raid is very fragile by default, the typical (nervous) breakdown situation is: I noticed a bad block on a drive, replace it, and the resync fails cause another 2-3 disks have hidden badblocks too. I've to save the disks and rebuild bad blocks with a userspace tool (by hand..), meanwhile the site is down for hours. bad; especially when a pair of simple steps enough to avoid from this atypical problem: 1. dont kick a drive on read error cause it is possible that 99.99% is useable and will help (to serve and to save data) if another drive show bad sectors in same array 2. let build a mirror _online_ to a spare and replace the source of the mirror with the spare when it's done. bad blocks not a problem unless same sector bad on two disks what's a rare case. in this way is possible to fix an array with partially failed drives without data loss and without downtime I'm not a programmer just a sysadm who admins a large software sata array, but my angry got bigger than my laziness, so I made this patch on this weekend.. I'm not understand every piece of the md code (eg. the if-forest of the handle_stripe :) yet, so this patch may be a bug-colony and wrong by design, but I've tested it under heavy stress with both of 'faulty' module and real disks, and it works fine! ideas, piece of advice, bugfix/enchancement is welcomed! (I know, raid6 could be another solution for this problem, but that's a large overhead too.) use: 1. patch the kernel, this one is against 2.6.11 2. type: # make drives mdadm -B -n1 -l faulty /dev/md/1 /dev/rd/0 mdadm -B -n1 -l faulty /dev/md/2 /dev/rd/1 mdadm -B -n1 -l faulty /dev/md/3 /dev/rd/2 # make the array mdadm -C -n3 -l5 /dev/md/0 /dev/md/1 /dev/md/2 /dev/md/3 # .. wait the sync .. # grow bad blocks as ma*tor does mdadm --grow -l faulty -p rp454 /dev/md/1 mdadm --grow -l faulty -p rp738 /dev/md/2 # add a spare mdadm -a /dev/md/0 /dev/rd/4 # -> fail a drive, sync begins <- # the md/1 will not marked as failed, this is the point, but if you want to, # you can issue this command again! mdadm -f /dev/md/0 /dev/md/1 # kernel: # resync from md1 to spare ram4 # added spare for active resync # .. wonder the read errors from md[12] and the sync goes on! # feel free to stress the md at this time, mkfs, dd, badblocks, etc # kernel: # raid5_spare_active: 3 in_sync 3->0 # /proc/mdstat: # md0 : active raid5 ram4[0] md3[2] md2[1] md1[0] # -> ram4 and md1 have same id, this means the spare is a complete mirror, # if you stop the array you can assembly it with ram4 instead of md1, # the superblock same both of them # check the mirror (stop write stress) mdadm --grow -l faulty -p none /dev/md/1 cmp /dev/md/0 /dev/rd/4 # hot-replace the mirrored -partially failed- device with the active spare # (yes, mark it as failed again, but if there's a syncing ot synced 'active spare' # the -f really fails the device or replace it with the synced spare) mdadm -f /dev/md/0 /dev/md/1 # kernel: # replace md1 with in_sync active spare ram4 # and voila! # /proc/mdstat: # md0 : active raid5 ram4[0] md3[2] md2[1] --- linux/include/linux/raid/raid5.h.orig 2005-03-03 23:51:29.000000000 +0100 +++ linux/include/linux/raid/raid5.h 2005-08-14 03:02:11.000000000 +0200 @@ -147,6 +147,7 @@ #define R5_UPTODATE 0 /* page contains current data */ #define R5_LOCKED 1 /* IO has been submitted on "req" */ #define R5_OVERWRITE 2 /* towrite covers whole page */ +#define R5_FAILED 8 /* failed to read this stripe */ /* and some that are internal to handle_stripe */ #define R5_Insync 3 /* rdev && rdev->in_sync at start */ #define R5_Wantread 4 /* want to schedule a read */ @@ -224,6 +225,8 @@ int inactive_blocked; /* release of inactive stripes blocked, * waiting for 25% to be free */ + int mirrorit; /* source for active spare resync */ + spinlock_t device_lock; struct disk_info disks[0]; }; --- linux/drivers/md/md.c.orig 2005-08-14 21:22:08.000000000 +0200 +++ linux/drivers/md/md.c 2005-08-14 17:20:15.000000000 +0200 @@ -3545,18 +3547,19 @@ /* no recovery is running. * remove any failed drives, then - * add spares if possible + * add spares if possible. + * Spare are also removed and re-added, to allow + * the personality to fail the re-add. */ - ITERATE_RDEV(mddev,rdev,rtmp) { + ITERATE_RDEV(mddev,rdev,rtmp) if (rdev->raid_disk >= 0 && - rdev->faulty && + (rdev->faulty || ! rdev->in_sync) && atomic_read(&rdev->nr_pending)==0) { +printk("md_check_recovery: hot_remove_disk\n"); if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0) rdev->raid_disk = -1; } - if (!rdev->faulty && rdev->raid_disk >= 0 && !rdev->in_sync) - spares++; - } + if (mddev->degraded) { ITERATE_RDEV(mddev,rdev,rtmp) if (rdev->raid_disk < 0 @@ -3764,4 +3771,5 @@ EXPORT_SYMBOL(md_wakeup_thread); EXPORT_SYMBOL(md_print_devices); EXPORT_SYMBOL(md_check_recovery); +EXPORT_SYMBOL(kick_rdev_from_array); // fixme MODULE_LICENSE("GPL"); --- linux/drivers/md/raid5.c.orig 2005-08-14 21:22:08.000000000 +0200 +++ linux/drivers/md/raid5.c 2005-08-14 20:49:49.000000000 +0200 @@ -53,7 +53,7 @@ /* * The following can be used to debug the driver */ -#define RAID5_DEBUG 0 +#define RAID5_DEBUG 1 #define RAID5_PARANOIA 1 #if RAID5_PARANOIA && defined(CONFIG_SMP) # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock) @@ -61,7 +61,7 @@ # define CHECK_DEVLOCK() #endif -#define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x))) +#define PRINTK(x...) ((void)(RAID5_DEBUG && printk(KERN_DEBUG x))) #if RAID5_DEBUG #define inline #define __inline__ @@ -201,7 +201,7 @@ sh->pd_idx = pd_idx; sh->state = 0; - for (i=disks; i--; ) { + for (i=disks+1; i--; ) { struct r5dev *dev = &sh->dev[i]; if (dev->toread || dev->towrite || dev->written || @@ -291,8 +291,10 @@ sprintf(conf->cache_name, "raid5/%s", mdname(conf->mddev)); + /* +1: we need extra space in the *sh->devs for the 'active spare' to keep + handle_stripe() simple */ sc = kmem_cache_create(conf->cache_name, - sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev), + sizeof(struct stripe_head)+(devs-1+1)*sizeof(struct r5dev), 0, 0, NULL, NULL); if (!sc) return 1; @@ -301,12 +303,12 @@ sh = kmem_cache_alloc(sc, GFP_KERNEL); if (!sh) return 1; - memset(sh, 0, sizeof(*sh) + (devs-1)*sizeof(struct r5dev)); + memset(sh, 0, sizeof(*sh) + (devs-1+1)*sizeof(struct r5dev)); sh->raid_conf = conf; spin_lock_init(&sh->lock); - if (grow_buffers(sh, conf->raid_disks)) { - shrink_buffers(sh, conf->raid_disks); + if (grow_buffers(sh, conf->raid_disks+1)) { + shrink_buffers(sh, conf->raid_disks+1); kmem_cache_free(sc, sh); return 1; } @@ -391,18 +393,39 @@ } #else set_bit(R5_UPTODATE, &sh->dev[i].flags); + clear_bit(R5_FAILED, &sh->dev[i].flags); #endif } else { - if (conf->working_disks < conf->raid_disks && !conf->mddev->curr_resync && - conf->disks[i].rdev->in_sync) { - char b[BDEVNAME_SIZE]; - printk (KERN_ALERT - "raid5_end_read_request: Disk failure on %s, but just failing this req.\n" - ,bdevname(conf->disks[i].rdev->bdev, b)); - conf->disks[i].rdev->rerr = 1; + char b[BDEVNAME_SIZE]; + + /* + rule 1.,: try to keep all disk in_sync even if we've got read errors, + cause the 'active spare' maybe can rebuild a complete column from + partially failed drives + */ + if (conf->disks[i].rdev->in_sync && conf->working_disks < conf->raid_disks) { + /* bad news, but keep it, cause md_error() would do a complete + array shutdown, even if 99.99% is useable */ + printk(KERN_ALERT + "raid5_end_read_request: Read failure %s on sector %llu (%d) in degraded mode\n" + ,bdevname(conf->disks[i].rdev->bdev, b), + (unsigned long long)sh->sector, atomic_read(&sh->count)); + if (conf->mddev->curr_resync) + /* raid5_add_disk() will no accept the spare again, + and will not loop forever */ + conf->mddev->degraded = 2; + } else if (conf->disks[i].rdev->in_sync && conf->working_disks >= conf->raid_disks) { + /* will be computed */ + printk(KERN_ALERT + "raid5_end_read_request: Read failure %s on sector %llu (%d) in optimal mode\n" + ,bdevname(conf->disks[i].rdev->bdev, b), + (unsigned long long)sh->sector, atomic_read(&sh->count)); + /* conf->disks[i].rerr++ */ } else + /* practically it never happens */ md_error(conf->mddev, conf->disks[i].rdev); clear_bit(R5_UPTODATE, &sh->dev[i].flags); + set_bit(R5_FAILED, &sh->dev[i].flags); } rdev_dec_pending(conf->disks[i].rdev, conf->mddev); #if 0 @@ -438,10 +461,11 @@ PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n", (unsigned long long)sh->sector, i, atomic_read(&sh->count), uptodate); + /* sorry if (i == disks) { BUG(); return 0; - } + }*/ spin_lock_irqsave(&conf->device_lock, flags); if (!uptodate) @@ -475,33 +499,142 @@ dev->req.bi_private = sh; dev->flags = 0; - if (i != sh->pd_idx) + if (i != sh->pd_idx && i < sh->raid_conf->raid_disks) /* active spare? */ dev->sector = compute_blocknr(sh, i); } +static int raid5_remove_disk(mddev_t *mddev, int number); +static int raid5_add_disk(mddev_t *mddev, mdk_rdev_t *rdev); +/*static*/ void kick_rdev_from_array(mdk_rdev_t * rdev); +//static void md_update_sb(mddev_t * mddev); static void error(mddev_t *mddev, mdk_rdev_t *rdev) { char b[BDEVNAME_SIZE]; + char b2[BDEVNAME_SIZE]; raid5_conf_t *conf = (raid5_conf_t *) mddev->private; PRINTK("raid5: error called\n"); if (!rdev->faulty) { - mddev->sb_dirty = 1; - if (rdev->in_sync) { - conf->working_disks--; - mddev->degraded++; - conf->failed_disks++; - rdev->in_sync = 0; - /* - * if recovery was running, make sure it aborts. - */ - set_bit(MD_RECOVERY_ERR, &mddev->recovery); - } - rdev->faulty = 1; - printk (KERN_ALERT - "raid5: Disk failure on %s, disabling device." - " Operation continuing on %d devices\n", - bdevname(rdev->bdev,b), conf->working_disks); + int mddisks = 0; + mdk_rdev_t *rd; + mdk_rdev_t *rdevs = NULL; + struct list_head *rtmp; + int i; + + ITERATE_RDEV(mddev,rd,rtmp) + { + printk(KERN_INFO "mddev%d: %s\n", mddisks, bdevname(rd->bdev,b)); + mddisks++; + } + for (i = 0; (rd = conf->disks[i].rdev); i++) { + printk(KERN_INFO "r5dev%d: %s\n", i, bdevname(rd->bdev,b)); + } + ITERATE_RDEV(mddev,rd,rtmp) + { + rdevs = rd; + break; + } +printk("%d %d > %d %d ins:%d %p\n", + mddev->raid_disks, mddisks, conf->raid_disks, mddev->degraded, rdev->in_sync, rdevs); + if (conf->disks[conf->raid_disks].rdev == rdev && rdev->in_sync) { + /* in_sync, but must be handled specially, don't let 'degraded++' */ + printk ("active spare failed %s (in_sync)\n", + bdevname(rdev->bdev,b)); + mddev->sb_dirty = 1; + rdev->in_sync = 0; + rdev->faulty = 1; + rdev->raid_disk = conf->raid_disks; /* me as myself, again ;) */ + conf->mirrorit = -1; + } else if (mddisks > conf->raid_disks && !mddev->degraded && rdev->in_sync) { + /* have active spare, array is optimal, removed disk member + of it (but not the active spare) */ + if (rdev->raid_disk == conf->mirrorit && conf->disks[conf->raid_disks].rdev) { + if (!conf->disks[conf->raid_disks].rdev->in_sync) { + printk(KERN_ALERT "disk %s failed and active spare isn't in_sync yet, readd as normal spare\n", + bdevname(rdev->bdev,b)); + /* maybe shouldn't stop here, but we can't call this disk as + 'active spare' anymore, cause it's a simple rebuild from + a degraded array, fear of bad blocks! */ + conf->mirrorit = -1; + goto letitgo; + } else { + int ret; + + /* hot replace the synced drive with the 'active spare' + this is really "hot", I can't see clearly the things + what I have to do here. :} + pray. */ + + printk(KERN_ALERT "replace %s with in_sync active spare %s\n", + bdevname(rdev->bdev,b), + bdevname(rdevs->bdev,b2)); + rdev->in_sync = 0; + rdev->faulty = 1; + + conf->mirrorit = -1; + + /* my God, am I sane? */ + while ((i = atomic_read(&rdev->nr_pending))) { + printk("waiting for disk %d .. %d\n", + rdev->raid_disk, i); + } + ret = raid5_remove_disk(mddev, rdev->raid_disk); + if (ret) { + printk(KERN_WARNING "raid5_remove_disk1: busy?!\n"); + return; // should it nothing to do + } + ret = raid5_add_disk(mddev, conf->disks[conf->raid_disks].rdev); + if (!ret) { + printk(KERN_WARNING "raid5_add_disk: no free slot?!\n"); + return; // .. + } + + while ((i = atomic_read(&conf->disks[conf->raid_disks].rdev->nr_pending))) { + printk("waiting for disk %d .. %d\n", + conf->raid_disks, i); + } + ret = raid5_remove_disk(mddev, conf->raid_disks); + if (ret) { + printk(KERN_WARNING "raid5_remove_disk2: busy?!\n"); + return; // .. + } + + conf->disks[rdev->raid_disk].rdev->in_sync = 1; + + /* borrowed from hot_remove_disk() */ + kick_rdev_from_array(rdev); + //md_update_sb(mddev); + } + } else { + /* in_sync disk failed (!degraded), trying to make a copy + to a spare {and we could call it 'active spare' from now:} */ + printk(KERN_ALERT "resync from %s to spare %s (%d)\n", + bdevname(rdev->bdev,b), + bdevname(rdevs->bdev,b2), + conf->raid_disks); + conf->mirrorit = rdev->raid_disk; + + mddev->degraded++; /* for call raid5_hot_add_disk(), reset there */ + } + } else { +letitgo: + mddev->sb_dirty = 1; + if (rdev->in_sync) { + conf->working_disks--; + mddev->degraded++; + conf->failed_disks++; + rdev->in_sync = 0; + /* + * if recovery was running, make sure it aborts. + */ + set_bit(MD_RECOVERY_ERR, &mddev->recovery); + } + rdev->faulty = 1; + printk (KERN_ALERT + "raid5: Disk failure on %s, disabling device." + " Operation continuing on %d devices\n", + bdevname(rdev->bdev,b), conf->working_disks); + } } } @@ -896,6 +1029,8 @@ int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0; int non_overwrite = 0; int failed_num=0; + int aspare=0, asparenum=-1; + struct disk_info *asparedev; struct r5dev *dev; PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n", @@ -907,9 +1042,16 @@ clear_bit(STRIPE_DELAYED, &sh->state); syncing = test_bit(STRIPE_SYNCING, &sh->state); + asparedev = &conf->disks[conf->raid_disks]; + if (!conf->mddev->degraded && asparedev->rdev && !asparedev->rdev->faulty && + conf->mirrorit != -1) { + aspare++; + asparenum = sh->raid_conf->mirrorit; + PRINTK("has aspare (%d)\n", asparenum); + } /* Now to look around and see what can be done */ - for (i=disks; i--; ) { + for (i=disks+aspare; i--; ) { mdk_rdev_t *rdev; dev = &sh->dev[i]; clear_bit(R5_Insync, &dev->flags); @@ -953,12 +1095,17 @@ } if (dev->written) written++; rdev = conf->disks[i].rdev; /* FIXME, should I be looking rdev */ - if (!rdev || !rdev->in_sync || rdev->rerr /*forced error*/) { + if (!rdev || !rdev->in_sync || + (test_bit(R5_FAILED, &dev->flags) && !test_bit(R5_UPTODATE, &dev->flags))) { failed++; failed_num = i; + PRINTK("device %d failed for this stripe r%p w%p\n", i, dev->toread, dev->towrite); } else set_bit(R5_Insync, &dev->flags); } + if (aspare && failed > 1) + failed--; /* failed = 1 means "all ok" if we've aspare, this is simplest + method to do our work */ PRINTK("locked=%d uptodate=%d to_read=%d" " to_write=%d failed=%d failed_num=%d\n", locked, uptodate, to_read, to_write, failed, failed_num); @@ -1000,14 +1147,8 @@ bi = bi2; } - /* fail any reads if this device is non-operational or - there's forced read error */ + /* fail any reads if this device is non-operational */ if (!test_bit(R5_Insync, &sh->dev[i].flags)) { - if (conf->disks[i].rdev && conf->disks[i].rdev->rerr) { - conf->disks[i].rdev->rerr = 0; - printk (KERN_NOTICE "raid5: forced error on %d (r%d w%d)\n", - i, to_read, to_write); - } bi = sh->dev[i].toread; sh->dev[i].toread = NULL; if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) @@ -1027,6 +1168,7 @@ spin_unlock_irq(&conf->device_lock); } if (failed > 1 && syncing) { + printk(KERN_ALERT "sync stopped by IO error\n"); md_done_sync(conf->mddev, STRIPE_SECTORS,0); clear_bit(STRIPE_SYNCING, &sh->state); syncing = 0; @@ -1198,6 +1340,22 @@ PRINTK("Writing block %d\n", i); locked++; set_bit(R5_Wantwrite, &sh->dev[i].flags); + if (aspare && i == asparenum) { + char *ps, *pd; + + /* mirroring this new block */ + PRINTK("Writing to aspare too %d->%d\n", + i, conf->raid_disks); + /*if (test_bit(R5_LOCKED, &sh->dev[conf->raid_disks].flags)) { + printk("bazmeg, ez lokkolt1!!!\n"); + }*/ + ps = page_address(sh->dev[i].page); + pd = page_address(sh->dev[conf->raid_disks].page); + /* better idea? */ + memcpy(pd, ps, STRIPE_SIZE); + set_bit(R5_LOCKED, &sh->dev[conf->raid_disks].flags); + set_bit(R5_Wantwrite, &sh->dev[conf->raid_disks].flags); + } if (!test_bit(R5_Insync, &sh->dev[i].flags) || (i==sh->pd_idx && failed == 0)) set_bit(STRIPE_INSYNC, &sh->state); @@ -1234,14 +1392,30 @@ if (failed==0) failed_num = sh->pd_idx; /* should be able to compute the missing block and write it to spare */ + if (aspare) + failed_num = asparenum; if (!test_bit(R5_UPTODATE, &sh->dev[failed_num].flags)) { if (uptodate+1 != disks) BUG(); compute_block(sh, failed_num); uptodate++; } + if (aspare) { + char *ps, *pd; + + ps = page_address(sh->dev[failed_num].page); + pd = page_address(sh->dev[conf->raid_disks].page); + memcpy(pd, ps, STRIPE_SIZE); + PRINTK("R5_Wantwrite to aspare, uptodate: %d %p->%p\n", + uptodate, ps, pd); + /*if (test_bit(R5_LOCKED, &sh->dev[conf->raid_disks].flags)) { + printk("bazmeg, ez lokkolt2!!!\n"); + }*/ + } if (uptodate != disks) BUG(); + if (aspare) + failed_num = conf->raid_disks; dev = &sh->dev[failed_num]; set_bit(R5_LOCKED, &dev->flags); set_bit(R5_Wantwrite, &dev->flags); @@ -1265,7 +1439,7 @@ bi->bi_size = 0; bi->bi_end_io(bi, bytes, 0); } - for (i=disks; i-- ;) { + for (i=disks+aspare; i-- ;) { int rw; struct bio *bi; mdk_rdev_t *rdev; @@ -1507,6 +1681,15 @@ unplug_slaves(mddev); return 0; } + /* if there is 1 or more failed drives and we are trying + * to resync, then assert that we are finished, because there is + * nothing we can do. + */ + if (mddev->degraded >= 1 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + int rv = (mddev->size << 1) - sector_nr; + md_done_sync(mddev, rv, 1); + return rv; + } x = sector_nr; chunk_offset = sector_div(x, sectors_per_chunk); @@ -1605,11 +1788,11 @@ } mddev->private = kmalloc (sizeof (raid5_conf_t) - + mddev->raid_disks * sizeof(struct disk_info), + + (mddev->raid_disks + 1) * sizeof(struct disk_info), GFP_KERNEL); if ((conf = mddev->private) == NULL) goto abort; - memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) ); + memset (conf, 0, sizeof (*conf) + (mddev->raid_disks + 1) * sizeof(struct disk_info) ); conf->mddev = mddev; if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL) @@ -1639,7 +1822,6 @@ disk->rdev = rdev; - rdev->rerr = 0; /* !!! */ if (rdev->in_sync) { char b[BDEVNAME_SIZE]; printk(KERN_INFO "raid5: device %s operational as raid" @@ -1650,6 +1832,7 @@ } conf->raid_disks = mddev->raid_disks; + conf->mirrorit = -1; /* * 0 for a fully functional array, 1 for a degraded array. */ @@ -1699,7 +1882,7 @@ } } memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + - conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; + (conf->raid_disks+1) * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; if (grow_stripes(conf, conf->max_nr_stripes)) { printk(KERN_ERR "raid5: couldn't allocate %dkB for buffers\n", memory); @@ -1859,6 +2042,17 @@ tmp->rdev->in_sync = 1; } } + tmp = conf->disks + i; + if (tmp->rdev && !tmp->rdev->faulty && !tmp->rdev->in_sync) { + /* sync done to the 'active spare' */ + tmp->rdev->in_sync = 1; + + printk(KERN_NOTICE "raid5_spare_active: %d in_sync %d->%d\n", + i, tmp->rdev->raid_disk, conf->mirrorit); + + /* scary..? :} */ + tmp->rdev->raid_disk = conf->mirrorit; + } print_raid5_conf(conf); return 0; } @@ -1872,6 +2066,7 @@ print_raid5_conf(conf); rdev = p->rdev; +printk("raid5_remove_disk %d\n", number); if (rdev) { if (rdev->in_sync || atomic_read(&rdev->nr_pending)) { @@ -1899,18 +2094,35 @@ int disk; struct disk_info *p; + if (mddev->degraded > 1) + /* no point adding a device */ + return 0; + /* * find the disk ... */ for (disk=0; disk < mddev->raid_disks; disk++) if ((p=conf->disks + disk)->rdev == NULL) { rdev->in_sync = 0; - rdev->rerr = 0; /* !!! */ rdev->raid_disk = disk; found = 1; p->rdev = rdev; break; } + + if (!found) { + /* array optimal, this should be the 'active spare' */ + conf->disks[disk].rdev = rdev; + rdev->in_sync = 0; + rdev->raid_disk = conf->raid_disks; + + mddev->degraded--; + found++; /* call resync */ + + printk(KERN_INFO "added spare for active resync\n"); + } + printk(KERN_INFO "raid5_add_disk: %d (%d)\n", disk, found); + print_raid5_conf(conf); return found; }
