From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: Fwd: [powerpc/Baremetal]Kernel OOPS while executing memory hotplug on Power8 baremetal From: Jens Axboe To: vrbagal1 , Bart Van Assche , kent.overstreet@gmail.com, snitzer@redhat.com, linux-block@vger.kernel.org Cc: linux-scsi@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sachinp@linux.vnet.ibm.com, Linuxppc-dev References: <042fc8ee69b74c57815c0edfdbb253495e9d7718.camel@wdc.com> Message-ID: Date: Thu, 7 Jun 2018 09:40:47 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 List-ID: On 6/7/18 8:45 AM, Jens Axboe wrote: > On 6/7/18 4:37 AM, vrbagal1 wrote: >> On 2018-06-07 13:12, Bart Van Assche wrote: >>> On Thu, 2018-06-07 at 12:56 +0530, Venkat Rao B wrote: >>>> On Thursday 07 June 2018 12:46 PM, Bart Van Assche wrote: >>>>> On Thu, 2018-06-07 at 12:38 +0530, vrbagal1 wrote: >>>>>> Observing Kernel oops and machine reboots while executing memory hotplug >>>>>> test case, on Power8 Baremetal machine. >>>>>> >>>>>> I see this is introduced some where between rc6 and 4.17. >>>>> >>>>> Please provide the exact versions (git commit IDs) of the kernel versions >>>>> you have tested. >>>> >>>> Commit Id ---> 5037be168f >>> >>> The reason I was asking for the commit ID is because I saw that >>> clone_endio() >>> occurs in the oops which means that the dm driver is involved. An >>> important fix >>> for the dm driver went upstream recently, namely d37753540568 ("dm: Use >>> kzalloc >>> for all structs with embedded biosets/mempools"). Can you double check >>> whether >>> that commit it present in your tree? If it is not present, please >>> update to the >>> latest master and retest. If it is present, please report how to >>> reproduce >>> this oops to Kent Overstreet, Jens Axboe, linux-block and Mike Snitzer. >>> >>> Thanks, >>> >>> Bart. >> >> >> Yes, the fix is present in the tree, which I have tested. >> >> Steps to reproduce: >> >> Step1: Clone and Install avocado git clone >> https://github.com/avocado-framework/avocado.git >> Step2: Clone >> https://github.com/avocado-framework-tests/avocado-misc-tests.git >> Test case is >> https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/memhotplug.py >> Step3: Command to run the test is avocado run >> avocado-misc-tests/memory/memhotplug.py > > Can you try with the below? Not a fully formed fix since I'd prefer > if the dm bioset copy stuff was changed instead, but worth a shot. This is closer to an actual fix, please try that instead. diff --git a/block/bio.c b/block/bio.c index 595663e0281a..0616d86b15c6 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1967,6 +1967,21 @@ int bioset_init(struct bio_set *bs, } EXPORT_SYMBOL(bioset_init); +int bioset_init_from_src(struct bio_set *new, struct bio_set *src) +{ + unsigned int pool_size = src->bio_pool.min_nr; + int flags; + + flags = 0; + if (src->bvec_pool.min_nr) + flags |= BIOSET_NEED_BVECS; + if (src->rescue_workqueue) + flags |= BIOSET_NEED_RESCUER; + + return bioset_init(new, pool_size, src->front_pad, flags); +} +EXPORT_SYMBOL(bioset_init_from_src); + #ifdef CONFIG_BLK_CGROUP /** diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 98dff36b89a3..20a8d63754bf 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1953,9 +1953,10 @@ static void free_dev(struct mapped_device *md) kvfree(md); } -static void __bind_mempools(struct mapped_device *md, struct dm_table *t) +static int __bind_mempools(struct mapped_device *md, struct dm_table *t) { struct dm_md_mempools *p = dm_table_get_md_mempools(t); + int ret = 0; if (dm_table_bio_based(t)) { /* @@ -1982,13 +1983,16 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t) bioset_initialized(&md->bs) || bioset_initialized(&md->io_bs)); - md->bs = p->bs; - memset(&p->bs, 0, sizeof(p->bs)); - md->io_bs = p->io_bs; - memset(&p->io_bs, 0, sizeof(p->io_bs)); + ret = bioset_init_from_src(&md->bs, &p->bs); + if (ret) + goto out; + ret = bioset_init_from_src(&md->io_bs, &p->io_bs); + if (ret) + bioset_exit(&md->bs); out: /* mempool bind completed, no longer need any mempools in the table */ dm_table_free_md_mempools(t); + return ret; } /* @@ -2033,6 +2037,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, struct request_queue *q = md->queue; bool request_based = dm_table_request_based(t); sector_t size; + int ret; lockdep_assert_held(&md->suspend_lock); @@ -2068,7 +2073,11 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, md->immutable_target = dm_table_get_immutable_target(t); } - __bind_mempools(md, t); + ret = __bind_mempools(md, t); + if (ret) { + old_map = ERR_PTR(ret); + goto out; + } old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); rcu_assign_pointer(md->map, (void *)t); @@ -2078,6 +2087,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, if (old_map) dm_sync_table(md); +out: return old_map; } diff --git a/include/linux/bio.h b/include/linux/bio.h index 810a8bee8f85..307682ac2f31 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -417,6 +417,7 @@ enum { extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); extern void bioset_exit(struct bio_set *); extern int biovec_init_pool(mempool_t *pool, int pool_entries); +extern int bioset_init_from_src(struct bio_set *new, struct bio_set *src); extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); extern void bio_put(struct bio *); -- Jens Axboe From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: Fwd: [powerpc/Baremetal]Kernel OOPS while executing memory hotplug on Power8 baremetal Date: Thu, 7 Jun 2018 09:40:47 -0600 Message-ID: References: <042fc8ee69b74c57815c0edfdbb253495e9d7718.camel@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: vrbagal1 , Bart Van Assche , kent.overstreet@gmail.com, snitzer@redhat.com, linux-block@vger.kernel.org Cc: sachinp@linux.vnet.ibm.com, Linuxppc-dev , linuxppc-dev@lists.ozlabs.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On 6/7/18 8:45 AM, Jens Axboe wrote: > On 6/7/18 4:37 AM, vrbagal1 wrote: >> On 2018-06-07 13:12, Bart Van Assche wrote: >>> On Thu, 2018-06-07 at 12:56 +0530, Venkat Rao B wrote: >>>> On Thursday 07 June 2018 12:46 PM, Bart Van Assche wrote: >>>>> On Thu, 2018-06-07 at 12:38 +0530, vrbagal1 wrote: >>>>>> Observing Kernel oops and machine reboots while executing memory hotplug >>>>>> test case, on Power8 Baremetal machine. >>>>>> >>>>>> I see this is introduced some where between rc6 and 4.17. >>>>> >>>>> Please provide the exact versions (git commit IDs) of the kernel versions >>>>> you have tested. >>>> >>>> Commit Id ---> 5037be168f >>> >>> The reason I was asking for the commit ID is because I saw that >>> clone_endio() >>> occurs in the oops which means that the dm driver is involved. An >>> important fix >>> for the dm driver went upstream recently, namely d37753540568 ("dm: Use >>> kzalloc >>> for all structs with embedded biosets/mempools"). Can you double check >>> whether >>> that commit it present in your tree? If it is not present, please >>> update to the >>> latest master and retest. If it is present, please report how to >>> reproduce >>> this oops to Kent Overstreet, Jens Axboe, linux-block and Mike Snitzer. >>> >>> Thanks, >>> >>> Bart. >> >> >> Yes, the fix is present in the tree, which I have tested. >> >> Steps to reproduce: >> >> Step1: Clone and Install avocado git clone >> https://github.com/avocado-framework/avocado.git >> Step2: Clone >> https://github.com/avocado-framework-tests/avocado-misc-tests.git >> Test case is >> https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/memhotplug.py >> Step3: Command to run the test is avocado run >> avocado-misc-tests/memory/memhotplug.py > > Can you try with the below? Not a fully formed fix since I'd prefer > if the dm bioset copy stuff was changed instead, but worth a shot. This is closer to an actual fix, please try that instead. diff --git a/block/bio.c b/block/bio.c index 595663e0281a..0616d86b15c6 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1967,6 +1967,21 @@ int bioset_init(struct bio_set *bs, } EXPORT_SYMBOL(bioset_init); +int bioset_init_from_src(struct bio_set *new, struct bio_set *src) +{ + unsigned int pool_size = src->bio_pool.min_nr; + int flags; + + flags = 0; + if (src->bvec_pool.min_nr) + flags |= BIOSET_NEED_BVECS; + if (src->rescue_workqueue) + flags |= BIOSET_NEED_RESCUER; + + return bioset_init(new, pool_size, src->front_pad, flags); +} +EXPORT_SYMBOL(bioset_init_from_src); + #ifdef CONFIG_BLK_CGROUP /** diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 98dff36b89a3..20a8d63754bf 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1953,9 +1953,10 @@ static void free_dev(struct mapped_device *md) kvfree(md); } -static void __bind_mempools(struct mapped_device *md, struct dm_table *t) +static int __bind_mempools(struct mapped_device *md, struct dm_table *t) { struct dm_md_mempools *p = dm_table_get_md_mempools(t); + int ret = 0; if (dm_table_bio_based(t)) { /* @@ -1982,13 +1983,16 @@ static void __bind_mempools(struct mapped_device *md, struct dm_table *t) bioset_initialized(&md->bs) || bioset_initialized(&md->io_bs)); - md->bs = p->bs; - memset(&p->bs, 0, sizeof(p->bs)); - md->io_bs = p->io_bs; - memset(&p->io_bs, 0, sizeof(p->io_bs)); + ret = bioset_init_from_src(&md->bs, &p->bs); + if (ret) + goto out; + ret = bioset_init_from_src(&md->io_bs, &p->io_bs); + if (ret) + bioset_exit(&md->bs); out: /* mempool bind completed, no longer need any mempools in the table */ dm_table_free_md_mempools(t); + return ret; } /* @@ -2033,6 +2037,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, struct request_queue *q = md->queue; bool request_based = dm_table_request_based(t); sector_t size; + int ret; lockdep_assert_held(&md->suspend_lock); @@ -2068,7 +2073,11 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, md->immutable_target = dm_table_get_immutable_target(t); } - __bind_mempools(md, t); + ret = __bind_mempools(md, t); + if (ret) { + old_map = ERR_PTR(ret); + goto out; + } old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); rcu_assign_pointer(md->map, (void *)t); @@ -2078,6 +2087,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, if (old_map) dm_sync_table(md); +out: return old_map; } diff --git a/include/linux/bio.h b/include/linux/bio.h index 810a8bee8f85..307682ac2f31 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -417,6 +417,7 @@ enum { extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags); extern void bioset_exit(struct bio_set *); extern int biovec_init_pool(mempool_t *pool, int pool_entries); +extern int bioset_init_from_src(struct bio_set *new, struct bio_set *src); extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *); extern void bio_put(struct bio *); -- Jens Axboe