From mboxrd@z Thu Jan 1 00:00:00 1970 From: Coly Li Subject: Re: [PATCH] bug fix for making cache device failed Date: Mon, 24 Sep 2018 22:46:38 +0800 Message-ID: <22662faa-22da-11c6-e093-c89ee86a448a@suse.de> References: <20180921061418.3131-1-cdbdyx@163.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20180921061418.3131-1-cdbdyx@163.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dongbo Cao Cc: kent.overstreet@gmail.com, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-bcache@vger.kernel.org On 9/21/18 2:14 PM, Dongbo Cao wrote: > 1)when the nbuckets of cache device is smaller than 1024, make cache device will trigger BUG_ON in kernel, add a condition to avoid this. > 2)split original if condition code into separate ones to make it clearly to debug. > > Signed-off-by: Dongbo Cao Hi Dongbo, In general the patch is good to me. But could you please to split this patch into 2 patches?  One is for split original if-condition code, one is for the panic fix. Then it might be more clear to me. Thanks. Coly Li > --- > drivers/md/bcache/super.c | 87 ++++++++++++++++++++++++++++++++------- > 1 file changed, 73 insertions(+), 14 deletions(-) > > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index fa4058e4..47d122ed 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -2017,6 +2017,8 @@ static int cache_alloc(struct cache *ca) > size_t free; > size_t btree_buckets; > struct bucket *b; > + int ret = -ENOMEM; > + const char *err = NULL; > > __module_get(THIS_MODULE); > kobject_init(&ca->kobj, &bch_cache_ktype); > @@ -2034,27 +2036,82 @@ static int cache_alloc(struct cache *ca) > */ > btree_buckets = ca->sb.njournal_buckets ?: 8; > free = roundup_pow_of_two(ca->sb.nbuckets) >> 10; > + if (!free) { > + ret = -EPERM; > + err = "ca->sb.nbuckets is too small"; > + goto err_free; > + } > > - if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, GFP_KERNEL) || > - !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) || > - !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) || > - !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) || > - !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) || > - !init_heap(&ca->heap, free << 3, GFP_KERNEL) || > - !(ca->buckets = vzalloc(array_size(sizeof(struct bucket), > - ca->sb.nbuckets))) || > - !(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t), > - prio_buckets(ca), 2), > - GFP_KERNEL)) || > - !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca))) > - return -ENOMEM; > + if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, > + GFP_KERNEL)) { > + err = "ca->free[RESERVE_BTREE] alloc failed"; > + goto err_btree_alloc; > + } > + if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), > + GFP_KERNEL)) { > + err = "ca->free[RESERVE_PRIO] alloc failed"; > + goto err_prio_alloc; > + } > + if (!init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL)) { > + err = "ca->free[RESERVE_MOVINGGC] alloc failed"; > + goto err_movinggc_alloc; > + } > + if (!init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL)) { > + err = "ca->free[RESERVE_NONE] alloc failed"; > + goto err_none_alloc; > + } > + if (!init_fifo(&ca->free_inc, free << 2, GFP_KERNEL)) { > + err = "ca->free_inc alloc failed"; > + goto err_free_inc_alloc; > + } > + if (!init_heap(&ca->heap, free << 3, GFP_KERNEL)) { > + err = "ca->heap alloc failed"; > + goto err_heap_alloc; > + } > + if (!(ca->buckets = vzalloc(array_size(sizeof(struct bucket), > + ca->sb.nbuckets)))) { > + err = "ca->buckets alloc failed"; > + goto err_buckets_alloc; > + } > + if (!(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t), > + prio_buckets(ca), 2), > + GFP_KERNEL))) { > + err = "ca->prio_buckets alloc failed"; > + goto err_prio_buckets_alloc; > + } > + if (!(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca))) { > + err = "ca->disk_buckets alloc failed"; > + goto err_disk_buckets_alloc; > + } > > ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca); > > for_each_bucket(b, ca) > atomic_set(&b->pin, 0); > - > return 0; > + > +err_disk_buckets_alloc: > + kfree(ca->prio_buckets); > +err_prio_buckets_alloc: > + vfree(ca->buckets); > +err_buckets_alloc: > + free_heap(&ca->heap); > +err_heap_alloc: > + free_fifo(&ca->free_inc); > +err_free_inc_alloc: > + free_fifo(&ca->free[RESERVE_NONE]); > +err_none_alloc: > + free_fifo(&ca->free[RESERVE_MOVINGGC]); > +err_movinggc_alloc: > + free_fifo(&ca->free[RESERVE_PRIO]); > +err_prio_alloc: > + free_fifo(&ca->free[RESERVE_BTREE]); > +err_btree_alloc: > +err_free: > + module_put(THIS_MODULE); > + if (err) > + pr_notice("error %s: %s", ca->cache_dev_name, err); > + return ret; > } > > static int register_cache(struct cache_sb *sb, struct page *sb_page, > @@ -2080,6 +2137,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page, > blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); > if (ret == -ENOMEM) > err = "cache_alloc(): -ENOMEM"; > + else if (ret == -EPERM) > + err = "cache_alloc(): cache device is too small"; > else > err = "cache_alloc(): unknown error"; > goto err;