diff options
| -rw-r--r-- | drivers/md/md.c | 346 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 134 |
2 files changed, 316 insertions, 164 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index ea839d811f64..c8d2bac4e28b 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3256,26 +3256,32 @@ static ssize_t level_store(struct mddev *mddev, const char *buf, size_t len) { char clevel[16]; - ssize_t rv = len; + ssize_t rv; + size_t slen = len; struct md_personality *pers, *oldpers; long level; void *priv, *oldpriv; struct md_rdev *rdev; + if (slen == 0 || slen >= sizeof(clevel)) + return -EINVAL; + + rv = mddev_lock(mddev); + if (rv) + return rv; + if (mddev->pers == NULL) { - if (len == 0) - return 0; - if (len >= sizeof(mddev->clevel)) - return -ENOSPC; - strncpy(mddev->clevel, buf, len); - if (mddev->clevel[len-1] == '\n') - len--; - mddev->clevel[len] = 0; + strncpy(mddev->clevel, buf, slen); + if (mddev->clevel[slen-1] == '\n') + slen--; + mddev->clevel[slen] = 0; mddev->level = LEVEL_NONE; - return rv; + rv = len; + goto out_unlock; } + rv = -EROFS; if (mddev->ro) - return -EROFS; + goto out_unlock; /* request to change the personality. Need to ensure: * - array is not engaged in resync/recovery/reshape @@ -3283,25 +3289,25 @@ level_store(struct mddev *mddev, const char *buf, size_t len) * - new personality will access other array. */ + rv = -EBUSY; if (mddev->sync_thread || test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || mddev->reshape_position != MaxSector || mddev->sysfs_active) - return -EBUSY; + goto out_unlock; + rv = -EINVAL; if (!mddev->pers->quiesce) { printk(KERN_WARNING "md: %s: %s does not support online personality change\n", mdname(mddev), mddev->pers->name); - return -EINVAL; + goto out_unlock; } /* Now find the new personality */ - if (len == 0 || len >= sizeof(clevel)) - return -EINVAL; - strncpy(clevel, buf, len); - if (clevel[len-1] == '\n') - len--; - clevel[len] = 0; + strncpy(clevel, buf, slen); + if (clevel[slen-1] == '\n') + slen--; + clevel[slen] = 0; if (kstrtol(clevel, 10, &level)) level = LEVEL_NONE; @@ -3312,20 +3318,23 @@ level_store(struct mddev *mddev, const char *buf, size_t len) if (!pers || !try_module_get(pers->owner)) { spin_unlock(&pers_lock); printk(KERN_WARNING "md: personality %s not loaded\n", clevel); - return -EINVAL; + rv = -EINVAL; + goto out_unlock; } spin_unlock(&pers_lock); if (pers == mddev->pers) { /* Nothing to do! */ module_put(pers->owner); - return rv; + rv = len; + goto out_unlock; } if (!pers->takeover) { module_put(pers->owner); printk(KERN_WARNING "md: %s: %s does not support personality takeover\n", mdname(mddev), clevel); - return -EINVAL; + rv = -EINVAL; + goto out_unlock; } rdev_for_each(rdev, mddev) @@ -3345,7 +3354,8 @@ level_store(struct mddev *mddev, const char *buf, size_t len) module_put(pers->owner); printk(KERN_WARNING "md: %s: %s would not accept array\n", mdname(mddev), clevel); - return PTR_ERR(priv); + rv = PTR_ERR(priv); + goto out_unlock; } /* Looks like we have a winner */ @@ -3438,6 +3448,9 @@ level_store(struct mddev *mddev, const char *buf, size_t len) md_update_sb(mddev, 1); sysfs_notify(&mddev->kobj, NULL, "level"); md_new_event(mddev); + rv = len; +out_unlock: + mddev_unlock(mddev); return rv; } @@ -3460,28 +3473,32 @@ layout_store(struct mddev *mddev, const char *buf, size_t len) { char *e; unsigned long n = simple_strtoul(buf, &e, 10); + int err; if (!*buf || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; if (mddev->pers) { - int err; if (mddev->pers->check_reshape == NULL) - return -EBUSY; - if (mddev->ro) - return -EROFS; - mddev->new_layout = n; - err = mddev->pers->check_reshape(mddev); - if (err) { - mddev->new_layout = mddev->layout; - return err; + err = -EBUSY; + else if (mddev->ro) + err = -EROFS; + else { + mddev->new_layout = n; + err = mddev->pers->check_reshape(mddev); + if (err) + mddev->new_layout = mddev->layout; } } else { mddev->new_layout = n; if (mddev->reshape_position == MaxSector) mddev->layout = n; } - return len; + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_layout = __ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store); @@ -3504,32 +3521,39 @@ static ssize_t raid_disks_store(struct mddev *mddev, const char *buf, size_t len) { char *e; - int rv = 0; + int err; unsigned long n = simple_strtoul(buf, &e, 10); if (!*buf || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; if (mddev->pers) - rv = update_raid_disks(mddev, n); + err = update_raid_disks(mddev, n); else if (mddev->reshape_position != MaxSector) { struct md_rdev *rdev; int olddisks = mddev->raid_disks - mddev->delta_disks; + err = -EINVAL; rdev_for_each(rdev, mddev) { if (olddisks < n && rdev->data_offset < rdev->new_data_offset) - return -EINVAL; + goto out_unlock; if (olddisks > n && rdev->data_offset > rdev->new_data_offset) - return -EINVAL; + goto out_unlock; } + err = 0; mddev->delta_disks = n - olddisks; mddev->raid_disks = n; mddev->reshape_backwards = (mddev->delta_disks < 0); } else mddev->raid_disks = n; - return rv ? rv : len; +out_unlock: + mddev_unlock(mddev); + return err ? err : len; } static struct md_sysfs_entry md_raid_disks = __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store); @@ -3548,30 +3572,34 @@ chunk_size_show(struct mddev *mddev, char *page) static ssize_t chunk_size_store(struct mddev *mddev, const char *buf, size_t len) { + int err; char *e; unsigned long n = simple_strtoul(buf, &e, 10); if (!*buf || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; if (mddev->pers) { - int err; if (mddev->pers->check_reshape == NULL) - return -EBUSY; - if (mddev->ro) - return -EROFS; - mddev->new_chunk_sectors = n >> 9; - err = mddev->pers->check_reshape(mddev); - if (err) { - mddev->new_chunk_sectors = mddev->chunk_sectors; - return err; + err = -EBUSY; + else if (mddev->ro) + err = -EROFS; + else { + mddev->new_chunk_sectors = n >> 9; + err = mddev->pers->check_reshape(mddev); + if (err) + mddev->new_chunk_sectors = mddev->chunk_sectors; } } else { mddev->new_chunk_sectors = n >> 9; if (mddev->reshape_position == MaxSector) mddev->chunk_sectors = n >> 9; } - return len; + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_chunk_size = __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store); @@ -3587,20 +3615,27 @@ resync_start_show(struct mddev *mddev, char *page) static ssize_t resync_start_store(struct mddev *mddev, const char *buf, size_t len) { + int err; char *e; unsigned long long n = simple_strtoull(buf, &e, 10); + err = mddev_lock(mddev); + if (err) + return err; if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) - return -EBUSY; - if (cmd_match(buf, "none")) + err = -EBUSY; + else if (cmd_match(buf, "none")) n = MaxSector; else if (!*buf || (*e && *e != '\n')) - return -EINVAL; + err = -EINVAL; - mddev->recovery_cp = n; - if (mddev->pers) - set_bit(MD_CHANGE_CLEAN, &mddev->flags); - return len; + if (!err) { + mddev->recovery_cp = n; + if (mddev->pers) + set_bit(MD_CHANGE_CLEAN, &mddev->flags); + } + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_resync_start = __ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store); @@ -3698,8 +3733,39 @@ static int restart_array(struct mddev *mddev); static ssize_t array_state_store(struct mddev *mddev, const char *buf, size_t len) { - int err = -EINVAL; + int err; enum array_state st = match_word(buf, array_states); + + if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) { + /* don't take reconfig_mutex when toggling between + * clean and active + */ + spin_lock(&mddev->lock); + if (st == active) { + restart_array(mddev); + clear_bit(MD_CHANGE_PENDING, &mddev->flags); + wake_up(&mddev->sb_wait); + err = 0; + } else /* st == clean */ { + restart_array(mddev); + if (atomic_read(&mddev->writes_pending) == 0) { + if (mddev->in_sync == 0) { + mddev->in_sync = 1; + if (mddev->safemode == 1) + mddev->safemode = 0; + set_bit(MD_CHANGE_CLEAN, &mddev->flags); + } + err = 0; + } else + err = -EBUSY; + } + spin_unlock(&mddev->lock); + return err; + } + err = mddev_lock(mddev); + if (err) + return err; + err = -EINVAL; switch(st) { case bad_word: break; @@ -3775,14 +3841,14 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len) /* these cannot be set */ break; } - if (err) - return err; - else { + + if (!err) { if (mddev->hold_active == UNTIL_IOCTL) mddev->hold_active = 0; sysfs_notify_dirent_safe(mddev->sysfs_state); - return len; } + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_array_state = __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store); @@ -3843,6 +3909,11 @@ new_dev_store(struct mddev *mddev, const char *buf, size_t len) minor != MINOR(dev)) return -EOVERFLOW; + flush_workqueue(md_misc_wq); + + err = mddev_lock(mddev); + if (err) + return err; if (mddev->persistent) { rdev = md_import_device(dev, mddev->major_version, mddev->minor_version); @@ -3866,6 +3937,7 @@ new_dev_store(struct mddev *mddev, const char *buf, size_t len) out: if (err) export_rdev(rdev); + mddev_unlock(mddev); return err ? err : len; } @@ -3877,7 +3949,11 @@ bitmap_store(struct mddev *mddev, const char *buf, size_t len) { char *end; unsigned long chunk, end_chunk; + int err; + err = mddev_lock(mddev); + if (err) + return err; if (!mddev->bitmap) goto out; /* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */ @@ -3895,6 +3971,7 @@ bitmap_store(struct mddev *mddev, const char *buf, size_t len) } bitmap_unplug(mddev->bitmap); /* flush the bits to disk */ out: + mddev_unlock(mddev); return len; } @@ -3922,6 +3999,9 @@ size_store(struct mddev *mddev, const char *buf, size_t len) if (err < 0) return err; + err = mddev_lock(mddev); + if (err) + return err; if (mddev->pers) { err = update_size(mddev, sectors); md_update_sb(mddev, 1); @@ -3932,6 +4012,7 @@ size_store(struct mddev *mddev, const char *buf, size_t len) else err = -ENOSPC; } + mddev_unlock(mddev); return err ? err : len; } @@ -3961,21 +4042,28 @@ metadata_store(struct mddev *mddev, const char *buf, size_t len) { int major, minor; char *e; + int err; /* Changing the details of 'external' metadata is * always permitted. Otherwise there must be * no devices attached to the array. */ + + err = mddev_lock(mddev); + if (err) + return err; + err = -EBUSY; if (mddev->external && strncmp(buf, "external:", 9) == 0) ; else if (!list_empty(&mddev->disks)) - return -EBUSY; + goto out_unlock; + err = 0; if (cmd_match(buf, "none")) { mddev->persistent = 0; mddev->external = 0; mddev->major_version = 0; mddev->minor_version = 90; - return len; + goto out_unlock; } if (strncmp(buf, "external:", 9) == 0) { size_t namelen = len-9; @@ -3989,22 +4077,27 @@ metadata_store(struct mddev *mddev, const char *buf, size_t len) mddev->external = 1; mddev->major_version = 0; mddev->minor_version = 90; - return len; + goto out_unlock; } major = simple_strtoul(buf, &e, 10); + err = -EINVAL; if (e==buf || *e != '.') - return -EINVAL; + goto out_unlock; buf = e+1; minor = simple_strtoul(buf, &e, 10); if (e==buf || (*e && *e != '\n') ) - return -EINVAL; + goto out_unlock; + err = -ENOENT; if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL) - return -ENOENT; + goto out_unlock; mddev->major_version = major; mddev->minor_version = minor; mddev->persistent = 1; mddev->external = 0; - return len; + err = 0; +out_unlock: + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_metadata = @@ -4049,7 +4142,10 @@ action_store(struct mddev *mddev, const char *page, size_t len) flush_workqueue(md_misc_wq); if (mddev->sync_thread) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); + if (mddev_lock(mddev) == 0) { + md_reap_sync_thread(mddev); + mddev_unlock(mddev); + } } } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) @@ -4063,7 +4159,11 @@ action_store(struct mddev *mddev, const char *page, size_t len) int err; if (mddev->pers->start_reshape == NULL) return -EINVAL; - err = mddev->pers->start_reshape(mddev); + err = mddev_lock(mddev); + if (!err) { + err = mddev->pers->start_reshape(mddev); + mddev_unlock(mddev); + } if (err) return err; sysfs_notify(&mddev->kobj, NULL, "degraded"); @@ -4346,14 +4446,20 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len) { char *e; unsigned long long new = simple_strtoull(buf, &e, 10); - unsigned long long old = mddev->suspend_lo; + unsigned long long old; + int err; - if (mddev->pers == NULL || - mddev->pers->quiesce == NULL) - return -EINVAL; if (buf == e || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; + err = -EINVAL; + if (mddev->pers == NULL || + mddev->pers->quiesce == NULL) + goto unlock; + old = mddev->suspend_lo; mddev->suspend_lo = new; if (new >= old) /* Shrinking suspended region */ @@ -4363,7 +4469,10 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len) mddev->pers->quiesce(mddev, 1); mddev->pers->quiesce(mddev, 0); } - return len; + err = 0; +unlock: + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_suspend_lo = __ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store); @@ -4379,14 +4488,20 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len) { char *e; unsigned long long new = simple_strtoull(buf, &e, 10); - unsigned long long old = mddev->suspend_hi; + unsigned long long old; + int err; - if (mddev->pers == NULL || - mddev->pers->quiesce == NULL) - return -EINVAL; if (buf == e || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; + err = -EINVAL; + if (mddev->pers == NULL || + mddev->pers->quiesce == NULL) + goto unlock; + old = mddev->suspend_hi; mddev->suspend_hi = new; if (new <= old) /* Shrinking suspended region */ @@ -4396,7 +4511,10 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len) mddev->pers->quiesce(mddev, 1); mddev->pers->quiesce(mddev, 0); } - return len; + err = 0; +unlock: + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_suspend_hi = __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store); @@ -4416,11 +4534,17 @@ reshape_position_store(struct mddev *mddev, const char *buf, size_t len) { struct md_rdev *rdev; char *e; + int err; unsigned long long new = simple_strtoull(buf, &e, 10); - if (mddev->pers) - return -EBUSY; + if (buf == e || (*e && *e != '\n')) return -EINVAL; + err = mddev_lock(mddev); + if (err) + return err; + err = -EBUSY; + if (mddev->pers) + goto unlock; mddev->reshape_position = new; mddev->delta_disks = 0; mddev->reshape_backwards = 0; @@ -4429,7 +4553,10 @@ reshape_position_store(struct mddev *mddev, const char *buf, size_t len) mddev->new_chunk_sectors = mddev->chunk_sectors; rdev_for_each(rdev, mddev) rdev->new_data_offset = rdev->data_offset; - return len; + err = 0; +unlock: + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_reshape_position = @@ -4447,6 +4574,8 @@ static ssize_t reshape_direction_store(struct mddev *mddev, const char *buf, size_t len) { int backwards = 0; + int err; + if (cmd_match(buf, "forwards")) backwards = 0; else if (cmd_match(buf, "backwards")) @@ -4456,16 +4585,19 @@ reshape_direction_store(struct mddev *mddev, const char *buf, size_t len) if (mddev->reshape_backwards == backwards) return len; + err = mddev_lock(mddev); + if (err) + return err; /* check if we are allowed to change */ if (mddev->delta_disks) - return -EBUSY; - - if (mddev->persistent && + err = -EBUSY; + else if (mddev->persistent && mddev->major_version == 0) - return -EINVAL; - - mddev->reshape_backwards = backwards; - return len; + err = -EINVAL; + else + mddev->reshape_backwards = backwards; + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_reshape_direction = @@ -4486,6 +4618,11 @@ static ssize_t array_size_store(struct mddev *mddev, const char *buf, size_t len) { sector_t sectors; + int err; + + err = mddev_lock(mddev); + if (err) + return err; if (strncmp(buf, "default", 7) == 0) { if (mddev->pers) @@ -4496,19 +4633,22 @@ array_size_store(struct mddev *mddev, const char *buf, size_t len) mddev->external_size = 0; } else { if (strict_blocks_to_sectors(buf, §ors) < 0) - return -EINVAL; - if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors) - return -E2BIG; - - mddev->external_size = 1; + err = -EINVAL; + else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors) + err = -E2BIG; + else + mddev->external_size = 1; } - mddev->array_sectors = sectors; - if (mddev->pers) { - set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); + if (!err) { + mddev->array_sectors = sectors; + if (mddev->pers) { + set_capacity(mddev->gendisk, mddev->array_sectors); + revalidate_disk(mddev->gendisk); + } } - return len; + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry md_array_size = @@ -4596,13 +4736,7 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, } mddev_get(mddev); spin_unlock(&all_mddevs_lock); - if (entry->store == new_dev_store) - flush_workqueue(md_misc_wq); - rv = mddev_lock(mddev); - if (!rv) { - rv = entry->store(mddev, page, length); - mddev_unlock(mddev); - } + rv = entry->store(mddev, page, length); mddev_put(mddev); return rv; } diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index d5b80174b3b3..aa76865b804b 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5400,21 +5400,25 @@ EXPORT_SYMBOL(raid5_set_cache_size); static ssize_t raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len) { - struct r5conf *conf = mddev->private; + struct r5conf *conf; unsigned long new; int err; if (len >= PAGE_SIZE) return -EINVAL; - if (!conf) - return -ENODEV; - if (kstrtoul(page, 10, &new)) return -EINVAL; - err = raid5_set_cache_size(mddev, new); + err = mddev_lock(mddev); if (err) return err; - return len; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else + err = raid5_set_cache_size(mddev, new); + mddev_unlock(mddev); + + return err ?: len; } static struct md_sysfs_entry @@ -5438,19 +5442,27 @@ raid5_show_preread_threshold(struct mddev *mddev, char *page) static ssize_t raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len) { - struct r5conf *conf = mddev->private; + struct r5conf *conf; unsigned long new; + int err; + if (len >= PAGE_SIZE) return -EINVAL; - if (!conf) - return -ENODEV; - if (kstrtoul(page, 10, &new)) return -EINVAL; - if (new > conf->max_nr_stripes) - return -EINVAL; - conf->bypass_threshold = new; - return len; + + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new > conf->max_nr_stripes) + err = -EINVAL; + else + conf->bypass_threshold = new; + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry @@ -5475,29 +5487,35 @@ raid5_show_skip_copy(struct mddev *mddev, char *page) static ssize_t raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len) { - struct r5conf *conf = mddev->private; + struct r5conf *conf; unsigned long new; + int err; + if (len >= PAGE_SIZE) return -EINVAL; - if (!conf) - return -ENODEV; - if (kstrtoul(page, 10, &new)) return -EINVAL; new = !!new; - if (new == conf->skip_copy) - return len; - mddev_suspend(mddev); - conf->skip_copy = new; - if (new) - mddev->queue->backing_dev_info.capabilities |= - BDI_CAP_STABLE_WRITES; - else - mddev->queue->backing_dev_info.capabilities &= - ~BDI_CAP_STABLE_WRITES; - mddev_resume(mddev); - return len; + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new != conf->skip_copy) { + mddev_suspend(mddev); + conf->skip_copy = new; + if (new) + mddev->queue->backing_dev_info.capabilities |= + BDI_CAP_STABLE_WRITES; + else + mddev->queue->backing_dev_info.capabilities &= + ~BDI_CAP_STABLE_WRITES; + mddev_resume(mddev); + } + mddev_unlock(mddev); + return err ?: len; } static struct md_sysfs_entry @@ -5538,7 +5556,7 @@ static int alloc_thread_groups(struct r5conf *conf, int cnt, static ssize_t raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len) { - struct r5conf *conf = mddev->private; + struct r5conf *conf; unsigned long new; int err; struct r5worker_group *new_groups, *old_groups; @@ -5546,41 +5564,41 @@ raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len) if (len >= PAGE_SIZE) return -EINVAL; - if (!conf) - return -ENODEV; - if (kstrtoul(page, 10, &new)) return -EINVAL; - if (new == conf->worker_cnt_per_group) - return len; - - mddev_suspend(mddev); + err = mddev_lock(mddev); + if (err) + return err; + conf = mddev->private; + if (!conf) + err = -ENODEV; + else if (new != conf->worker_cnt_per_group) { + mddev_suspend(mddev); - old_groups = conf->worker_groups; - if (old_groups) - flush_workqueue(raid5_wq); + old_groups = conf->worker_groups; + if (old_groups) + flush_workqueue(raid5_wq); - err = alloc_thread_groups(conf, new, - &group_cnt, &worker_cnt_per_group, - &new_groups); - if (!err) { - spin_lock_irq(&conf->device_lock); - conf->group_cnt = group_cnt; - conf->worker_cnt_per_group = worker_cnt_per_group; - conf->worker_groups = new_groups; - spin_unlock_irq(&conf->device_lock); + err = alloc_thread_groups(conf, new, + &group_cnt, &worker_cnt_per_group, + &new_groups); + if (!err) { + spin_lock_irq(&conf->device_lock); + conf->group_cnt = group_cnt; + conf->worker_cnt_per_group = worker_cnt_per_group; + conf->worker_groups = new_groups; + spin_unlock_irq(&conf->device_lock); - if (old_groups) - kfree(old_groups[0].workers); - kfree(old_groups); + if (old_groups) + kfree(old_groups[0].workers); + kfree(old_groups); + } + mddev_resume(mddev); } + mddev_unlock(mddev); - mddev_resume(mddev); - - if (err) - return err; - return len; + return err ?: len; } static struct md_sysfs_entry |