* [PATCH v5 1/5] block: free both rq_map and request
2020-05-05 6:43 [PATCH v5 0/5] Fix potential kernel panic when increase hardware queue Weiping Zhang
@ 2020-05-05 6:43 ` Weiping Zhang
2020-05-07 6:10 ` Christoph Hellwig
2020-05-05 6:43 ` [PATCH v5 2/5] block: save previous hardware queue count before udpate Weiping Zhang
` (3 subsequent siblings)
4 siblings, 1 reply; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 6:43 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
Allocation:
__blk_mq_alloc_rq_map
blk_mq_alloc_rq_map
blk_mq_alloc_rq_map
tags = blk_mq_init_tags : kzalloc_node:
tags->rqs = kcalloc_node
tags->static_rqs = kcalloc_node
blk_mq_alloc_rqs
p = alloc_pages_node
tags->static_rqs[i] = p + offset;
Free:
blk_mq_free_rq_map
kfree(tags->rqs);
kfree(tags->static_rqs);
blk_mq_free_tags
kfree(tags);
The page allocated in blk_mq_alloc_rqs cannot be released,
so we should use blk_mq_free_map_and_requests here.
blk_mq_free_map_and_requests
blk_mq_free_rqs
__free_pages : cleanup for blk_mq_alloc_rqs
blk_mq_free_rq_map : cleanup for blk_mq_alloc_rq_map
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a7785df2c944..f789b3e1b3ab 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2995,7 +2995,7 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
out_unwind:
while (--i >= 0)
- blk_mq_free_rq_map(set->tags[i]);
+ blk_mq_free_map_and_requests(set, i);
return -ENOMEM;
}
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 2/5] block: save previous hardware queue count before udpate
2020-05-05 6:43 [PATCH v5 0/5] Fix potential kernel panic when increase hardware queue Weiping Zhang
2020-05-05 6:43 ` [PATCH v5 1/5] block: free both rq_map and request Weiping Zhang
@ 2020-05-05 6:43 ` Weiping Zhang
2020-05-07 6:11 ` Christoph Hellwig
2020-05-05 6:45 ` [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map Weiping Zhang
` (2 subsequent siblings)
4 siblings, 1 reply; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 6:43 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
blk_mq_realloc_tag_set_tags will update set->nr_hw_queues, so
save old set->nr_hw_queues before call this function.
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f789b3e1b3ab..a79afbe60ca6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3347,11 +3347,11 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
blk_mq_sysfs_unregister(q);
}
+ prev_nr_hw_queues = set->nr_hw_queues;
if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) <
0)
goto reregister;
- prev_nr_hw_queues = set->nr_hw_queues;
set->nr_hw_queues = nr_hw_queues;
blk_mq_update_queue_map(set);
fallback:
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map
2020-05-05 6:43 [PATCH v5 0/5] Fix potential kernel panic when increase hardware queue Weiping Zhang
2020-05-05 6:43 ` [PATCH v5 1/5] block: free both rq_map and request Weiping Zhang
2020-05-05 6:43 ` [PATCH v5 2/5] block: save previous hardware queue count before udpate Weiping Zhang
@ 2020-05-05 6:45 ` Weiping Zhang
2020-05-07 6:11 ` Christoph Hellwig
2020-05-05 6:46 ` [PATCH v5 5/5] block: rename blk_mq_alloc_rq_maps Weiping Zhang
2020-05-05 7:38 ` [RESEND PATCH " Weiping Zhang
4 siblings, 1 reply; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 6:45 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request,
actually it alloc both map and request, make function name
align with function.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c6ba94cba17d..02af33f56daa 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2473,7 +2473,7 @@ static void blk_mq_init_cpu_queues(struct request_queue *q,
}
}
-static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
+static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, int hctx_idx)
{
int ret = 0;
@@ -2532,7 +2532,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
hctx_idx = set->map[j].mq_map[i];
/* unmapped hw queue can be remapped after CPU topo changed */
if (!set->tags[hctx_idx] &&
- !__blk_mq_alloc_rq_map(set, hctx_idx)) {
+ !__blk_mq_alloc_map_and_request(set, hctx_idx)) {
/*
* If tags initialization fail for some hctx,
* that hctx won't be brought online. In this
@@ -2988,7 +2988,7 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
int i;
for (i = 0; i < set->nr_hw_queues; i++)
- if (!__blk_mq_alloc_rq_map(set, i))
+ if (!__blk_mq_alloc_map_and_request(set, i))
goto out_unwind;
return 0;
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map
2020-05-05 6:45 ` [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map Weiping Zhang
@ 2020-05-07 6:11 ` Christoph Hellwig
2020-05-07 12:59 ` Weiping Zhang
0 siblings, 1 reply; 13+ messages in thread
From: Christoph Hellwig @ 2020-05-07 6:11 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche, linux-block
On Tue, May 05, 2020 at 02:45:58PM +0800, Weiping Zhang wrote:
> rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request,
> actually it alloc both map and request, make function name
> align with function.
>
> Reviewed-by: Ming Lei <ming.lei@redhat.com>
> Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
> ---
> block/blk-mq.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index c6ba94cba17d..02af33f56daa 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2473,7 +2473,7 @@ static void blk_mq_init_cpu_queues(struct request_queue *q,
> }
> }
>
> -static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
> +static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, int hctx_idx)
Please fix the > 80 char line here.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map
2020-05-07 6:11 ` Christoph Hellwig
@ 2020-05-07 12:59 ` Weiping Zhang
0 siblings, 0 replies; 13+ messages in thread
From: Weiping Zhang @ 2020-05-07 12:59 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Jens Axboe, tom.leiming, Bart Van Assche, linux-block
On Thu, May 7, 2020 at 2:12 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Tue, May 05, 2020 at 02:45:58PM +0800, Weiping Zhang wrote:
> > rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request,
> > actually it alloc both map and request, make function name
> > align with function.
> >
> > Reviewed-by: Ming Lei <ming.lei@redhat.com>
> > Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
> > ---
> > block/blk-mq.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/block/blk-mq.c b/block/blk-mq.c
> > index c6ba94cba17d..02af33f56daa 100644
> > --- a/block/blk-mq.c
> > +++ b/block/blk-mq.c
> > @@ -2473,7 +2473,7 @@ static void blk_mq_init_cpu_queues(struct request_queue *q,
> > }
> > }
> >
> > -static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
> > +static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, int hctx_idx)
>
> Please fix the > 80 char line here.
OK, fix in v6.
Thanks
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v5 5/5] block: rename blk_mq_alloc_rq_maps
2020-05-05 6:43 [PATCH v5 0/5] Fix potential kernel panic when increase hardware queue Weiping Zhang
` (2 preceding siblings ...)
2020-05-05 6:45 ` [PATCH v5 4/5] block: rename __blk_mq_alloc_rq_map Weiping Zhang
@ 2020-05-05 6:46 ` Weiping Zhang
2020-05-07 6:11 ` Christoph Hellwig
2020-05-05 7:38 ` [RESEND PATCH " Weiping Zhang
4 siblings, 1 reply; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 6:46 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
rename blk_mq_alloc_rq_maps to blk_mq_alloc_map_and_requests,
this function allocs both map and request, make function name align
with funtion.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 02af33f56daa..c2b2562dfe7e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3005,7 +3005,7 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
* may reduce the depth asked for, if memory is tight. set->queue_depth
* will be updated to reflect the allocated depth.
*/
-static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
+static int blk_mq_alloc_map_and_requests(struct blk_mq_tag_set *set)
{
unsigned int depth;
int err;
@@ -3165,7 +3165,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
if (ret)
goto out_free_mq_map;
- ret = blk_mq_alloc_rq_maps(set);
+ ret = blk_mq_alloc_map_and_requests(set);
if (ret)
goto out_free_mq_map;
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v5 5/5] block: rename blk_mq_alloc_rq_maps
2020-05-05 6:46 ` [PATCH v5 5/5] block: rename blk_mq_alloc_rq_maps Weiping Zhang
@ 2020-05-07 6:11 ` Christoph Hellwig
0 siblings, 0 replies; 13+ messages in thread
From: Christoph Hellwig @ 2020-05-07 6:11 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche, linux-block
On Tue, May 05, 2020 at 02:46:07PM +0800, Weiping Zhang wrote:
> rename blk_mq_alloc_rq_maps to blk_mq_alloc_map_and_requests,
> this function allocs both map and request, make function name align
> with funtion.
>
> Reviewed-by: Ming Lei <ming.lei@redhat.com>
> Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v5 3/5] block: alloc map and request for new hardware queue
@ 2020-05-05 7:38 ` Weiping Zhang
0 siblings, 0 replies; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 7:02 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
Alloc new map and request for new hardware queue when increse
hardware queue count. Before this patch, it will show a
warning for each new hardware queue, but it's not enough, these
hctx have no maps and reqeust, when a bio was mapped to these
hardware queue, it will trigger kernel panic when get request
from these hctx.
Test environment:
* A NVMe disk supports 128 io queues
* 96 cpus in system
A corner case can always trigger this panic, there are 96
io queues allocated for HCTX_TYPE_DEFAULT type, the corresponding kernel
log: nvme nvme0: 96/0/0 default/read/poll queues. Now we set nvme write
queues to 96, then nvme will alloc others(32) queues for read, but
blk_mq_update_nr_hw_queues does not alloc map and request for these new
added io queues. So when process read nvme disk, it will trigger kernel
panic when get request from these hardware context.
Reproduce script:
nr=$(expr `cat /sys/block/nvme0n1/device/queue_count` - 1)
echo $nr > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller
dd if=/dev/nvme0n1 of=/dev/null bs=4K count=1
[ 8040.805626] ------------[ cut here ]------------
[ 8040.805627] WARNING: CPU: 82 PID: 12921 at block/blk-mq.c:2578 blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805627] Modules linked in: nvme nvme_core nf_conntrack_netlink xt_addrtype br_netfilter overlay xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nf_conntrack_tftp nft_masq nf_tables_set nft_fib_inet nft_f
ib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack tun bridge nf_defrag_ipv6 nf_defrag_ipv4 stp llc ip6_tables ip_tables nft_compat rfkill ip_set nf_tables nfne
tlink sunrpc intel_rapl_msr intel_rapl_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass ipmi_ssif crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_clmulni_intel intel_
cstate intel_uncore raid0 joydev intel_rapl_perf ipmi_si pcspkr mei_me ioatdma sg ipmi_devintf mei i2c_i801 dca lpc_ich ipmi_msghandler acpi_power_meter acpi_pad xfs libcrc32c sd_mod ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm d
rm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 8040.805637] ahci drm i40e libahci crc32c_intel libata t10_pi wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nvme_core]
[ 8040.805640] CPU: 82 PID: 12921 Comm: kworker/u194:2 Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2
[ 8040.805640] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8040.805641] Workqueue: nvme-reset-wq nvme_reset_work [nvme]
[ 8040.805642] RIP: 0010:blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805643] Code: 00 00 00 00 00 41 83 c5 01 44 39 6d 50 77 b8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b bb 98 00 00 00 89 d6 e8 8c 81 03 00 eb 83 <0f> 0b e9 52 ff ff ff 0f 1f 00 0f 1f 44 00 00 41 57 48 89 f1 41 56
[ 8040.805643] RSP: 0018:ffffba590d2e7d48 EFLAGS: 00010246
[ 8040.805643] RAX: 0000000000000000 RBX: ffff9f013e1ba800 RCX: 000000000000003d
[ 8040.805644] RDX: ffff9f00ffff6000 RSI: 0000000000000003 RDI: ffff9ed200246d90
[ 8040.805644] RBP: ffff9f00f6a79860 R08: 0000000000000000 R09: 000000000000003d
[ 8040.805645] R10: 0000000000000001 R11: ffff9f0138c3d000 R12: ffff9f00fb3a9008
[ 8040.805645] R13: 000000000000007f R14: ffffffff96822660 R15: 000000000000005f
[ 8040.805645] FS: 0000000000000000(0000) GS:ffff9f013fa80000(0000) knlGS:0000000000000000
[ 8040.805646] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8040.805646] CR2: 00007f7f397fa6f8 CR3: 0000003d8240a002 CR4: 00000000007606e0
[ 8040.805647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8040.805647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8040.805647] PKRU: 55555554
[ 8040.805647] Call Trace:
[ 8040.805649] blk_mq_update_nr_hw_queues+0x31b/0x390
[ 8040.805650] nvme_reset_work+0xb4b/0xeab [nvme]
[ 8040.805651] process_one_work+0x1a7/0x370
[ 8040.805652] worker_thread+0x1c9/0x380
[ 8040.805653] ? max_active_store+0x80/0x80
[ 8040.805655] kthread+0x112/0x130
[ 8040.805656] ? __kthread_parkme+0x70/0x70
[ 8040.805657] ret_from_fork+0x35/0x40
[ 8040.805658] ---[ end trace b5f13b1e73ccb5d3 ]---
[ 8229.365135] BUG: kernel NULL pointer dereference, address: 0000000000000004
[ 8229.365165] #PF: supervisor read access in kernel mode
[ 8229.365178] #PF: error_code(0x0000) - not-present page
[ 8229.365191] PGD 0 P4D 0
[ 8229.365201] Oops: 0000 [#1] SMP PTI
[ 8229.365212] CPU: 77 PID: 13024 Comm: dd Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2
[ 8229.365232] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8229.365253] RIP: 0010:blk_mq_get_tag+0x227/0x250
[ 8229.365265] Code: 44 24 04 44 01 e0 48 8b 74 24 38 65 48 33 34 25 28 00 00 00 75 33 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e c3 48 8d 68 10 4c 89 ef <44> 8b 60 04 48 89 ee e8 dd f9 ff ff 83 f8 ff 75 c8 e9 67 fe ff ff
[ 8229.365304] RSP: 0018:ffffba590e977970 EFLAGS: 00010246
[ 8229.365317] RAX: 0000000000000000 RBX: ffff9f00f6a79860 RCX: ffffba590e977998
[ 8229.365333] RDX: 0000000000000000 RSI: ffff9f012039b140 RDI: ffffba590e977a38
[ 8229.365349] RBP: 0000000000000010 R08: ffffda58ff94e190 R09: ffffda58ff94e198
[ 8229.365365] R10: 0000000000000011 R11: ffff9f00f6a79860 R12: 0000000000000000
[ 8229.365381] R13: ffffba590e977a38 R14: ffff9f012039b140 R15: 0000000000000001
[ 8229.365397] FS: 00007f481c230580(0000) GS:ffff9f013f940000(0000) knlGS:0000000000000000
[ 8229.365415] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8229.365428] CR2: 0000000000000004 CR3: 0000005f35e26004 CR4: 00000000007606e0
[ 8229.365444] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8229.365460] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8229.365476] PKRU: 55555554
[ 8229.365484] Call Trace:
[ 8229.365498] ? finish_wait+0x80/0x80
[ 8229.365512] blk_mq_get_request+0xcb/0x3f0
[ 8229.365525] blk_mq_make_request+0x143/0x5d0
[ 8229.365538] generic_make_request+0xcf/0x310
[ 8229.365553] ? scan_shadow_nodes+0x30/0x30
[ 8229.365564] submit_bio+0x3c/0x150
[ 8229.365576] mpage_readpages+0x163/0x1a0
[ 8229.365588] ? blkdev_direct_IO+0x490/0x490
[ 8229.365601] read_pages+0x6b/0x190
[ 8229.365612] __do_page_cache_readahead+0x1c1/0x1e0
[ 8229.365626] ondemand_readahead+0x182/0x2f0
[ 8229.365639] generic_file_buffered_read+0x590/0xab0
[ 8229.365655] new_sync_read+0x12a/0x1c0
[ 8229.365666] vfs_read+0x8a/0x140
[ 8229.365676] ksys_read+0x59/0xd0
[ 8229.365688] do_syscall_64+0x55/0x1d0
[ 8229.365700] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Tested-by: Weiping Zhang <zhangweiping@didiglobal.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a79afbe60ca6..c6ba94cba17d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2521,18 +2521,6 @@ static void blk_mq_map_swqueue(struct request_queue *q)
* If the cpu isn't present, the cpu is mapped to first hctx.
*/
for_each_possible_cpu(i) {
- hctx_idx = set->map[HCTX_TYPE_DEFAULT].mq_map[i];
- /* unmapped hw queue can be remapped after CPU topo changed */
- if (!set->tags[hctx_idx] &&
- !__blk_mq_alloc_rq_map(set, hctx_idx)) {
- /*
- * If tags initialization fail for some hctx,
- * that hctx won't be brought online. In this
- * case, remap the current ctx to hctx[0] which
- * is guaranteed to always have tags allocated
- */
- set->map[HCTX_TYPE_DEFAULT].mq_map[i] = 0;
- }
ctx = per_cpu_ptr(q->queue_ctx, i);
for (j = 0; j < set->nr_maps; j++) {
@@ -2541,6 +2529,18 @@ static void blk_mq_map_swqueue(struct request_queue *q)
HCTX_TYPE_DEFAULT, i);
continue;
}
+ hctx_idx = set->map[j].mq_map[i];
+ /* unmapped hw queue can be remapped after CPU topo changed */
+ if (!set->tags[hctx_idx] &&
+ !__blk_mq_alloc_rq_map(set, hctx_idx)) {
+ /*
+ * If tags initialization fail for some hctx,
+ * that hctx won't be brought online. In this
+ * case, remap the current ctx to hctx[0] which
+ * is guaranteed to always have tags allocated
+ */
+ set->map[j].mq_map[i] = 0;
+ }
hctx = blk_mq_map_queue_type(q, j, i);
ctx->hctxs[j] = hctx;
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* [RESEND PATCH v5 3/5] block: alloc map and request for new hardware queue
@ 2020-05-05 7:38 ` Weiping Zhang
0 siblings, 0 replies; 13+ messages in thread
From: Weiping Zhang @ 2020-05-05 7:38 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche; +Cc: linux-block
From: Ming Lei <ming.lei@redhat.com>
Alloc new map and request for new hardware queue when increse
hardware queue count. Before this patch, it will show a
warning for each new hardware queue, but it's not enough, these
hctx have no maps and reqeust, when a bio was mapped to these
hardware queue, it will trigger kernel panic when get request
from these hctx.
Test environment:
* A NVMe disk supports 128 io queues
* 96 cpus in system
A corner case can always trigger this panic, there are 96
io queues allocated for HCTX_TYPE_DEFAULT type, the corresponding kernel
log: nvme nvme0: 96/0/0 default/read/poll queues. Now we set nvme write
queues to 96, then nvme will alloc others(32) queues for read, but
blk_mq_update_nr_hw_queues does not alloc map and request for these new
added io queues. So when process read nvme disk, it will trigger kernel
panic when get request from these hardware context.
Reproduce script:
nr=$(expr `cat /sys/block/nvme0n1/device/queue_count` - 1)
echo $nr > /sys/module/nvme/parameters/write_queues
echo 1 > /sys/block/nvme0n1/device/reset_controller
dd if=/dev/nvme0n1 of=/dev/null bs=4K count=1
[ 8040.805626] ------------[ cut here ]------------
[ 8040.805627] WARNING: CPU: 82 PID: 12921 at block/blk-mq.c:2578 blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805627] Modules linked in: nvme nvme_core nf_conntrack_netlink xt_addrtype br_netfilter overlay xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nf_conntrack_tftp nft_masq nf_tables_set nft_fib_inet nft_f
ib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack tun bridge nf_defrag_ipv6 nf_defrag_ipv4 stp llc ip6_tables ip_tables nft_compat rfkill ip_set nf_tables nfne
tlink sunrpc intel_rapl_msr intel_rapl_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass ipmi_ssif crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_clmulni_intel intel_
cstate intel_uncore raid0 joydev intel_rapl_perf ipmi_si pcspkr mei_me ioatdma sg ipmi_devintf mei i2c_i801 dca lpc_ich ipmi_msghandler acpi_power_meter acpi_pad xfs libcrc32c sd_mod ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm d
rm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 8040.805637] ahci drm i40e libahci crc32c_intel libata t10_pi wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nvme_core]
[ 8040.805640] CPU: 82 PID: 12921 Comm: kworker/u194:2 Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2
[ 8040.805640] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8040.805641] Workqueue: nvme-reset-wq nvme_reset_work [nvme]
[ 8040.805642] RIP: 0010:blk_mq_map_swqueue+0x2b6/0x2c0
[ 8040.805643] Code: 00 00 00 00 00 41 83 c5 01 44 39 6d 50 77 b8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b bb 98 00 00 00 89 d6 e8 8c 81 03 00 eb 83 <0f> 0b e9 52 ff ff ff 0f 1f 00 0f 1f 44 00 00 41 57 48 89 f1 41 56
[ 8040.805643] RSP: 0018:ffffba590d2e7d48 EFLAGS: 00010246
[ 8040.805643] RAX: 0000000000000000 RBX: ffff9f013e1ba800 RCX: 000000000000003d
[ 8040.805644] RDX: ffff9f00ffff6000 RSI: 0000000000000003 RDI: ffff9ed200246d90
[ 8040.805644] RBP: ffff9f00f6a79860 R08: 0000000000000000 R09: 000000000000003d
[ 8040.805645] R10: 0000000000000001 R11: ffff9f0138c3d000 R12: ffff9f00fb3a9008
[ 8040.805645] R13: 000000000000007f R14: ffffffff96822660 R15: 000000000000005f
[ 8040.805645] FS: 0000000000000000(0000) GS:ffff9f013fa80000(0000) knlGS:0000000000000000
[ 8040.805646] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8040.805646] CR2: 00007f7f397fa6f8 CR3: 0000003d8240a002 CR4: 00000000007606e0
[ 8040.805647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8040.805647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8040.805647] PKRU: 55555554
[ 8040.805647] Call Trace:
[ 8040.805649] blk_mq_update_nr_hw_queues+0x31b/0x390
[ 8040.805650] nvme_reset_work+0xb4b/0xeab [nvme]
[ 8040.805651] process_one_work+0x1a7/0x370
[ 8040.805652] worker_thread+0x1c9/0x380
[ 8040.805653] ? max_active_store+0x80/0x80
[ 8040.805655] kthread+0x112/0x130
[ 8040.805656] ? __kthread_parkme+0x70/0x70
[ 8040.805657] ret_from_fork+0x35/0x40
[ 8040.805658] ---[ end trace b5f13b1e73ccb5d3 ]---
[ 8229.365135] BUG: kernel NULL pointer dereference, address: 0000000000000004
[ 8229.365165] #PF: supervisor read access in kernel mode
[ 8229.365178] #PF: error_code(0x0000) - not-present page
[ 8229.365191] PGD 0 P4D 0
[ 8229.365201] Oops: 0000 [#1] SMP PTI
[ 8229.365212] CPU: 77 PID: 13024 Comm: dd Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2
[ 8229.365232] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019
[ 8229.365253] RIP: 0010:blk_mq_get_tag+0x227/0x250
[ 8229.365265] Code: 44 24 04 44 01 e0 48 8b 74 24 38 65 48 33 34 25 28 00 00 00 75 33 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e c3 48 8d 68 10 4c 89 ef <44> 8b 60 04 48 89 ee e8 dd f9 ff ff 83 f8 ff 75 c8 e9 67 fe ff ff
[ 8229.365304] RSP: 0018:ffffba590e977970 EFLAGS: 00010246
[ 8229.365317] RAX: 0000000000000000 RBX: ffff9f00f6a79860 RCX: ffffba590e977998
[ 8229.365333] RDX: 0000000000000000 RSI: ffff9f012039b140 RDI: ffffba590e977a38
[ 8229.365349] RBP: 0000000000000010 R08: ffffda58ff94e190 R09: ffffda58ff94e198
[ 8229.365365] R10: 0000000000000011 R11: ffff9f00f6a79860 R12: 0000000000000000
[ 8229.365381] R13: ffffba590e977a38 R14: ffff9f012039b140 R15: 0000000000000001
[ 8229.365397] FS: 00007f481c230580(0000) GS:ffff9f013f940000(0000) knlGS:0000000000000000
[ 8229.365415] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8229.365428] CR2: 0000000000000004 CR3: 0000005f35e26004 CR4: 00000000007606e0
[ 8229.365444] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8229.365460] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8229.365476] PKRU: 55555554
[ 8229.365484] Call Trace:
[ 8229.365498] ? finish_wait+0x80/0x80
[ 8229.365512] blk_mq_get_request+0xcb/0x3f0
[ 8229.365525] blk_mq_make_request+0x143/0x5d0
[ 8229.365538] generic_make_request+0xcf/0x310
[ 8229.365553] ? scan_shadow_nodes+0x30/0x30
[ 8229.365564] submit_bio+0x3c/0x150
[ 8229.365576] mpage_readpages+0x163/0x1a0
[ 8229.365588] ? blkdev_direct_IO+0x490/0x490
[ 8229.365601] read_pages+0x6b/0x190
[ 8229.365612] __do_page_cache_readahead+0x1c1/0x1e0
[ 8229.365626] ondemand_readahead+0x182/0x2f0
[ 8229.365639] generic_file_buffered_read+0x590/0xab0
[ 8229.365655] new_sync_read+0x12a/0x1c0
[ 8229.365666] vfs_read+0x8a/0x140
[ 8229.365676] ksys_read+0x59/0xd0
[ 8229.365688] do_syscall_64+0x55/0x1d0
[ 8229.365700] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Tested-by: Weiping Zhang <zhangweiping@didiglobal.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
---
block/blk-mq.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a79afbe60ca6..c6ba94cba17d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2521,18 +2521,6 @@ static void blk_mq_map_swqueue(struct request_queue *q)
* If the cpu isn't present, the cpu is mapped to first hctx.
*/
for_each_possible_cpu(i) {
- hctx_idx = set->map[HCTX_TYPE_DEFAULT].mq_map[i];
- /* unmapped hw queue can be remapped after CPU topo changed */
- if (!set->tags[hctx_idx] &&
- !__blk_mq_alloc_rq_map(set, hctx_idx)) {
- /*
- * If tags initialization fail for some hctx,
- * that hctx won't be brought online. In this
- * case, remap the current ctx to hctx[0] which
- * is guaranteed to always have tags allocated
- */
- set->map[HCTX_TYPE_DEFAULT].mq_map[i] = 0;
- }
ctx = per_cpu_ptr(q->queue_ctx, i);
for (j = 0; j < set->nr_maps; j++) {
@@ -2541,6 +2529,18 @@ static void blk_mq_map_swqueue(struct request_queue *q)
HCTX_TYPE_DEFAULT, i);
continue;
}
+ hctx_idx = set->map[j].mq_map[i];
+ /* unmapped hw queue can be remapped after CPU topo changed */
+ if (!set->tags[hctx_idx] &&
+ !__blk_mq_alloc_rq_map(set, hctx_idx)) {
+ /*
+ * If tags initialization fail for some hctx,
+ * that hctx won't be brought online. In this
+ * case, remap the current ctx to hctx[0] which
+ * is guaranteed to always have tags allocated
+ */
+ set->map[j].mq_map[i] = 0;
+ }
hctx = blk_mq_map_queue_type(q, j, i);
ctx->hctxs[j] = hctx;
--
2.18.1
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v5 3/5] block: alloc map and request for new hardware queue
2020-05-05 7:38 ` [RESEND PATCH " Weiping Zhang
(?)
@ 2020-05-07 6:13 ` Christoph Hellwig
-1 siblings, 0 replies; 13+ messages in thread
From: Christoph Hellwig @ 2020-05-07 6:13 UTC (permalink / raw)
To: axboe, tom.leiming, bvanassche, linux-block
The patch looks good, although I'm not a fan of the long backtraces
in the commit log..
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 13+ messages in thread