From patchwork Sun Jan 14 14:42:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 10162649 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6016A60390 for ; Sun, 14 Jan 2018 14:44:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4B14D28A9B for ; Sun, 14 Jan 2018 14:44:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F9F528AAE; Sun, 14 Jan 2018 14:44:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A199228A9B for ; Sun, 14 Jan 2018 14:44:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751916AbeANOo1 (ORCPT ); Sun, 14 Jan 2018 09:44:27 -0500 Received: from mx2.suse.de ([195.135.220.15]:49181 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbeANOo1 (ORCPT ); Sun, 14 Jan 2018 09:44:27 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EE3F2AAB6; Sun, 14 Jan 2018 14:44:25 +0000 (UTC) From: Coly Li To: linux-bcache@vger.kernel.org Cc: linux-block@vger.kernel.org, Coly Li , Michael Lyle , Hannes Reinecke , Junhui Tang Subject: [PATCH v3 12/13] bcache: add io_disable to struct cached_dev Date: Sun, 14 Jan 2018 22:42:35 +0800 Message-Id: <20180114144236.28213-13-colyli@suse.de> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180114144236.28213-1-colyli@suse.de> References: <20180114144236.28213-1-colyli@suse.de> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a bcache device is configured to writeback mode, current code does not handle write I/O errors on backing devices properly. In writeback mode, write request is written to cache device, and latter being flushed to backing device. If I/O failed when writing from cache device to the backing device, bcache code just ignores the error and upper layer code is NOT noticed that the backing device is broken. This patch tries to handle backing device failure like how the cache device failure is handled, - Add a error counter 'io_errors' and error limit 'error_limit' in struct cached_dev. Add another io_disable to struct cached_dev to disable I/Os on the problematic backing device. - When I/O error happens on backing device, increase io_errors counter. And if io_errors reaches error_limit, set cache_dev->io_disable to true, and stop the bcache device. The result is, if backing device is broken of disconnected, and I/O errors reach its error limit, backing device will be disabled and the associated bcache device will be removed from system. Signed-off-by: Coly Li Cc: Michael Lyle Cc: Hannes Reinecke Cc: Junhui Tang Reviewed-by: Hannes Reinecke --- drivers/md/bcache/bcache.h | 7 +++++++ drivers/md/bcache/io.c | 14 ++++++++++++++ drivers/md/bcache/request.c | 14 ++++++++++++-- drivers/md/bcache/super.c | 22 ++++++++++++++++++++++ drivers/md/bcache/sysfs.c | 15 ++++++++++++++- 5 files changed, 69 insertions(+), 3 deletions(-) diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index c41736960045..5a811959392d 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -360,6 +360,7 @@ struct cached_dev { unsigned sequential_cutoff; unsigned readahead; + unsigned io_disable:1; unsigned verify:1; unsigned bypass_torture_test:1; @@ -379,6 +380,10 @@ struct cached_dev { unsigned writeback_rate_i_term_inverse; unsigned writeback_rate_p_term_inverse; unsigned writeback_rate_minimum; + +#define DEFAULT_CACHED_DEV_ERROR_LIMIT 64 + atomic_t io_errors; + unsigned error_limit; }; enum alloc_reserve { @@ -882,6 +887,7 @@ static inline void closure_bio_submit(struct cache_set *c, /* Forward declarations */ +void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio); void bch_count_io_errors(struct cache *, blk_status_t, int, const char *); void bch_bbio_count_io_errors(struct cache_set *, struct bio *, blk_status_t, const char *); @@ -909,6 +915,7 @@ int bch_bucket_alloc_set(struct cache_set *, unsigned, struct bkey *, int, bool); bool bch_alloc_sectors(struct cache_set *, struct bkey *, unsigned, unsigned, unsigned, bool); +bool bch_cached_dev_error(struct cached_dev *dc); __printf(2, 3) bool bch_cache_set_error(struct cache_set *, const char *, ...); diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c index 8013ecbcdbda..7fac97ae036e 100644 --- a/drivers/md/bcache/io.c +++ b/drivers/md/bcache/io.c @@ -50,6 +50,20 @@ void bch_submit_bbio(struct bio *bio, struct cache_set *c, } /* IO errors */ +void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio) +{ + char buf[BDEVNAME_SIZE]; + unsigned errors; + + WARN_ONCE(!dc, "NULL pointer of struct cached_dev"); + + errors = atomic_add_return(1, &dc->io_errors); + if (errors < dc->error_limit) + pr_err("%s: IO error on backing device, unrecoverable", + bio_devname(bio, buf)); + else + bch_cached_dev_error(dc); +} void bch_count_io_errors(struct cache *ca, blk_status_t error, diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index ad4cf71f7eab..386b388ce296 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -637,6 +637,8 @@ static void backing_request_endio(struct bio *bio) if (bio->bi_status) { struct search *s = container_of(cl, struct search, cl); + struct cached_dev *dc = container_of(s->d, + struct cached_dev, disk); /* * If a bio has REQ_PREFLUSH for writeback mode, it is * speically assembled in cached_dev_write() for a non-zero @@ -657,6 +659,7 @@ static void backing_request_endio(struct bio *bio) } s->recoverable = false; /* should count I/O error for backing device here */ + bch_count_backing_io_errors(dc, bio); } bio_put(bio); @@ -1067,8 +1070,14 @@ static void detatched_dev_end_io(struct bio *bio) bio_data_dir(bio), &ddip->d->disk->part0, ddip->start_time); - kfree(ddip); + if (bio->bi_status) { + struct cached_dev *dc = container_of(ddip->d, + struct cached_dev, disk); + /* should count I/O error for backing device here */ + bch_count_backing_io_errors(dc, bio); + } + kfree(ddip); bio->bi_end_io(bio); } @@ -1107,7 +1116,8 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q, struct cached_dev *dc = container_of(d, struct cached_dev, disk); int rw = bio_data_dir(bio); - if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) { + if (unlikely((d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags)) || + dc->io_disable)) { bio->bi_status = BLK_STS_IOERR; bio_endio(bio); return BLK_QC_T_NONE; diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 08a0b541a4da..14fce3623770 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1188,6 +1188,10 @@ 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); + atomic_set(&dc->io_errors, 0); + dc->io_disable = false; + dc->error_limit = DEFAULT_CACHED_DEV_ERROR_LIMIT; + bch_cached_dev_request_init(dc); bch_cached_dev_writeback_init(dc); return 0; @@ -1339,6 +1343,24 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size) return flash_dev_run(c, u); } +bool bch_cached_dev_error(struct cached_dev *dc) +{ + char name[BDEVNAME_SIZE]; + + if (!dc || test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags)) + return false; + + dc->io_disable = true; + /* make others know io_disable is true earlier */ + smp_mb(); + + pr_err("bcache: stop %s: too many IO errors on backing device %s\n", + dc->disk.name, bdevname(dc->bdev, name)); + + bcache_device_stop(&dc->disk); + return true; +} + /* Cache set */ __printf(2, 3) diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index afb051bcfca1..7288927f2a47 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -131,7 +131,9 @@ SHOW(__bch_cached_dev) var_print(writeback_delay); var_print(writeback_percent); sysfs_hprint(writeback_rate, dc->writeback_rate.rate << 9); - + sysfs_hprint(io_errors, atomic_read(&dc->io_errors)); + sysfs_printf(io_error_limit, "%i", dc->error_limit); + sysfs_printf(io_disable, "%i", dc->io_disable); var_print(writeback_rate_update_seconds); var_print(writeback_rate_i_term_inverse); var_print(writeback_rate_p_term_inverse); @@ -223,6 +225,14 @@ STORE(__cached_dev) d_strtoul(writeback_rate_i_term_inverse); d_strtoul_nonzero(writeback_rate_p_term_inverse); + sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX); + + if (attr == &sysfs_io_disable) { + int v = strtoul_or_return(buf); + + dc->io_disable = v ? 1 : 0; + } + d_strtoi_h(sequential_cutoff); d_strtoi_h(readahead); @@ -330,6 +340,9 @@ static struct attribute *bch_cached_dev_files[] = { &sysfs_writeback_rate_i_term_inverse, &sysfs_writeback_rate_p_term_inverse, &sysfs_writeback_rate_debug, + &sysfs_errors, + &sysfs_io_error_limit, + &sysfs_io_disable, &sysfs_dirty_data, &sysfs_stripe_size, &sysfs_partial_stripes_expensive,