diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 8a0327581d62..5e9f3610c6fd 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -288,6 +288,12 @@ struct io { sector_t last; }; +enum stop_on_failure { + BCH_CACHED_DEV_STOP_AUTO = 0, + BCH_CACHED_DEV_STOP_ALWAYS, + BCH_CACHED_DEV_STOP_MODE_MAX, +}; + struct cached_dev { struct list_head list; struct bcache_device disk; @@ -380,6 +386,8 @@ struct cached_dev { unsigned writeback_rate_i_term_inverse; unsigned writeback_rate_p_term_inverse; unsigned writeback_rate_minimum; + + enum stop_on_failure stop_when_cache_set_failed; }; enum alloc_reserve { @@ -939,6 +947,7 @@ void bch_write_bdev_super(struct cached_dev *, struct closure *); extern struct workqueue_struct *bcache_wq; extern const char * const bch_cache_modes[]; +extern const char * const bch_stop_on_failure_modes[]; extern struct mutex bch_register_lock; extern struct list_head bch_cache_sets; diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index dda4ccdd1360..7b45160e9a22 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -47,6 +47,14 @@ const char * const bch_cache_modes[] = { NULL }; +/* Default is -1; we skip past it for stop_when_cache_set_failed */ +const char * const bch_stop_on_failure_modes[] = { + "default", + "auto", + "always", + NULL +}; + static struct kobject *bcache_kobj; struct mutex bch_register_lock; LIST_HEAD(bch_cache_sets); @@ -1188,6 +1196,9 @@ static int cached_dev_init(struct cached_dev *dc, unsigned block_size) max(dc->disk.disk->queue->backing_dev_info->ra_pages, q->backing_dev_info->ra_pages); + /* default to auto */ + dc->stop_when_cache_set_failed = BCH_CACHED_DEV_STOP_AUTO; + bch_cached_dev_request_init(dc); bch_cached_dev_writeback_init(dc); return 0; @@ -1464,25 +1475,72 @@ static void cache_set_flush(struct closure *cl) closure_return(cl); } +/* + * This function is only called when CACHE_SET_IO_DISABLE is set, which means + * cache set is unregistering due to too many I/O errors. In this condition, + * the bcache device might be stopped, it depends on stop_when_cache_set_failed + * value and whether the broken cache has dirty data: + * + * dc->stop_when_cache_set_failed dc->has_dirty stop bcache device + * BCH_CACHED_STOP_AUTO 0 NO + * BCH_CACHED_STOP_AUTO 1 YES + * BCH_CACHED_DEV_STOP_ALWAYS 0 YES + * BCH_CACHED_DEV_STOP_ALWAYS 1 YES + * + * The expected behavior is, if stop_when_cache_set_failed is configured to + * "auto" via sysfs interface, the bcache device will not be stopped if the + * backing device is clean on the broken cache device. + */ +static void conditional_stop_bcache_device(struct cache_set *c, + struct bcache_device *d, + struct cached_dev *dc) +{ + if (dc->stop_when_cache_set_failed == BCH_CACHED_DEV_STOP_ALWAYS) { + pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.", + d->disk->disk_name, c->sb.set_uuid); + bcache_device_stop(d); + } else if (atomic_read(&dc->has_dirty)) { + /* + * dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO + * and dc->has_dirty == 1 + */ + pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.", + d->disk->disk_name); + bcache_device_stop(d); + } else { + /* + * dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO + * and dc->has_dirty == 0 + */ + pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is clean, keep it alive.", + d->disk->disk_name); + } +} + static void __cache_set_unregister(struct closure *cl) { struct cache_set *c = container_of(cl, struct cache_set, caching); struct cached_dev *dc; + struct bcache_device *d; size_t i; mutex_lock(&bch_register_lock); - for (i = 0; i < c->devices_max_used; i++) - if (c->devices[i]) { - if (!UUID_FLASH_ONLY(&c->uuids[i]) && - test_bit(CACHE_SET_UNREGISTERING, &c->flags)) { - dc = container_of(c->devices[i], - struct cached_dev, disk); - bch_cached_dev_detach(dc); - } else { - bcache_device_stop(c->devices[i]); - } + for (i = 0; i < c->devices_max_used; i++) { + d = c->devices[i]; + if (!d) + continue; + + if (!UUID_FLASH_ONLY(&c->uuids[i]) && + test_bit(CACHE_SET_UNREGISTERING, &c->flags)) { + dc = container_of(d, struct cached_dev, disk); + bch_cached_dev_detach(dc); + if (test_bit(CACHE_SET_IO_DISABLE, &c->flags)) + conditional_stop_bcache_device(c, d, dc); + } else { + bcache_device_stop(d); } + } mutex_unlock(&bch_register_lock); diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index a3a45de5626d..414129f7c49f 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -78,6 +78,7 @@ rw_attribute(congested_write_threshold_us); rw_attribute(sequential_cutoff); rw_attribute(data_csum); rw_attribute(cache_mode); +rw_attribute(stop_when_cache_set_failed); rw_attribute(writeback_metadata); rw_attribute(writeback_running); rw_attribute(writeback_percent); @@ -126,6 +127,12 @@ SHOW(__bch_cached_dev) bch_cache_modes + 1, BDEV_CACHE_MODE(&dc->sb)); + if (attr == &sysfs_stop_when_cache_set_failed) + return bch_snprint_string_list(buf, PAGE_SIZE, + bch_stop_on_failure_modes + 1, + dc->stop_when_cache_set_failed); + + sysfs_printf(data_csum, "%i", dc->disk.data_csum); var_printf(verify, "%i"); var_printf(bypass_torture_test, "%i"); @@ -247,6 +254,15 @@ STORE(__cached_dev) } } + if (attr == &sysfs_stop_when_cache_set_failed) { + v = bch_read_string_list(buf, bch_stop_on_failure_modes + 1); + + if (v < 0) + return v; + + dc->stop_when_cache_set_failed = v; + } + if (attr == &sysfs_label) { if (size > SB_LABEL_SIZE) return -EINVAL; @@ -326,6 +342,7 @@ static struct attribute *bch_cached_dev_files[] = { &sysfs_data_csum, #endif &sysfs_cache_mode, + &sysfs_stop_when_cache_set_failed, &sysfs_writeback_metadata, &sysfs_writeback_running, &sysfs_writeback_delay,