Re: [PATCH 1/1] um: ubd: Fix data corruption
From: richard -rw- weinberger
Date: Thu Oct 14 2010 - 10:20:20 EST
On Thu, Oct 14, 2010 at 3:14 PM, Tejun Heo <htejun@xxxxxxxxx> wrote:
> Hello,
>
> Can you please try this one then? It seems to work here but I can't
> reproduce the original problem reliably so I'm not really sure.
>
> Thanks.
>
> diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
> index 1bcd208..9734994 100644
> --- a/arch/um/drivers/ubd_kern.c
> +++ b/arch/um/drivers/ubd_kern.c
> @@ -163,6 +163,7 @@ struct ubd {
> struct scatterlist sg[MAX_SG];
> struct request *request;
> int start_sg, end_sg;
> + sector_t rq_pos;
> };
>
> #define DEFAULT_COW { \
> @@ -187,6 +188,7 @@ struct ubd {
> .request = NULL, \
> .start_sg = 0, \
> .end_sg = 0, \
> + .rq_pos = 0, \
> }
>
> /* Protected by ubd_lock */
> @@ -1228,7 +1230,6 @@ static void do_ubd_request(struct request_queue *q)
> {
> struct io_thread_req *io_req;
> struct request *req;
> - sector_t sector;
> int n;
>
> while(1){
> @@ -1239,12 +1240,12 @@ static void do_ubd_request(struct request_queue *q)
> return;
>
> dev->request = req;
> + dev->rq_pos = blk_rq_pos(req);
> dev->start_sg = 0;
> dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
> }
>
> req = dev->request;
> - sector = blk_rq_pos(req);
> while(dev->start_sg < dev->end_sg){
> struct scatterlist *sg = &dev->sg[dev->start_sg];
>
> @@ -1256,10 +1257,9 @@ static void do_ubd_request(struct request_queue *q)
> return;
> }
> prepare_request(req, io_req,
> - (unsigned long long)sector << 9,
> + (unsigned long long)dev->rq_pos << 9,
> sg->offset, sg->length, sg_page(sg));
>
> - sector += sg->length >> 9;
> n = os_write_file(thread_fd, &io_req,
> sizeof(struct io_thread_req *));
> if(n != sizeof(struct io_thread_req *)){
> @@ -1272,6 +1272,7 @@ static void do_ubd_request(struct request_queue *q)
> return;
> }
>
> + dev->rq_pos += sg->length >> 9;
> dev->start_sg++;
> }
> dev->end_sg = 0;
It does not work for me.
But the error is a different one. :-)
Without your patch I've never got this kernel trace.
[ 59.850000] kworker/0:1: page allocation failure. order:0, mode:0x20
[ 59.850000] 0fe22d68: [<081ca1da>] dump_stack+0x1c/0x20
[ 59.850000] 0fe22d80: [<080a4981>] __alloc_pages_nodemask+0x4a0/0x4cb
[ 59.850000] 0fe22e00: [<080bd2d7>] cache_alloc_refill+0x213/0x3fe
[ 59.850000] 0fe22e58: [<080bd5db>] kmem_cache_alloc+0x62/0x8f
[ 59.850000] 0fe22e74: [<08062a4c>] do_ubd_request+0x91/0x40c
[ 59.850000] 0fe22edc: [<08148f01>] __blk_run_queue+0x40/0x6e
[ 59.850000] 0fe22ef0: [<08151280>] cfq_kick_queue+0x24/0x39
[ 59.850000] 0fe22f08: [<08083c86>] process_one_work+0x1ea/0x2f0
[ 59.850000] 0fe22f44: [<08084202>] worker_thread+0x174/0x2e4
[ 59.850000] 0fe22f74: [<08087e5b>] kthread+0x78/0x7f
[ 59.850000] 0fe22fb4: [<08066117>] run_kernel_thread+0x37/0x3f
[ 59.850000] 0fe22fe0: [<08059bd1>] new_thread_handler+0x60/0x87
[ 59.850000] 0fe22ffc: [<00000000>] 0x0
[ 59.850000]
[ 59.850000] Mem-Info:
[ 59.850000] Normal per-cpu:
[ 59.850000] CPU 0: hi: 42, btch: 7 usd: 15
[ 59.850000] active_anon:1146 inactive_anon:1194 isolated_anon:0
[ 59.850000] active_file:4314 inactive_file:19869 isolated_file:0
[ 59.850000] unevictable:0 dirty:1327 writeback:1837 unstable:0
[ 59.850000] free:131 slab_reclaimable:3618 slab_unreclaimable:1141
[ 59.850000] mapped:1105 shmem:10 pagetables:82 bounce:0
[ 59.850000] Normal free:524kB min:1440kB low:1800kB high:2160kB
active_anon:4584kB inactive_anon:4776kB active_file:17256kB
inactive_file:79476kB unevictable:0kB isolated(anon):0kB
isolated(file):0kB present:130048kB mlocked:0kB dirty:5308kB
writeback:7348kB mapped:4420kB shmem:40kB slab_reclaimable:14472kB
slab_unreclaimable:4564kB kernel_stack:164kB pagetables:328kB
unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? no
[ 59.850000] lowmem_reserve[]: 0 0
[ 59.850000] Normal: 1*4kB 3*8kB 25*16kB 3*32kB 0*64kB 0*128kB
0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 524kB
[ 59.850000] 24193 total pagecache pages
[ 59.850000] 0 pages in swap cache
[ 59.850000] Swap cache stats: add 0, delete 0, find 0/0
[ 59.850000] Free swap = 0kB
[ 59.850000] Total swap = 0kB
[ 59.850000] 32768 pages RAM
[ 59.850000] 1132 pages reserved
[ 59.850000] 26071 pages shared
[ 59.850000] 8225 pages non-shared
[ 94.930000] kworker/0:1: page allocation failure. order:0, mode:0x20
[ 94.930000] 0fe22d68: [<081ca1da>] dump_stack+0x1c/0x20
[ 94.930000] 0fe22d80: [<080a4981>] __alloc_pages_nodemask+0x4a0/0x4cb
[ 94.930000] 0fe22e00: [<080bd2d7>] cache_alloc_refill+0x213/0x3fe
[ 94.930000] 0fe22e58: [<080bd5db>] kmem_cache_alloc+0x62/0x8f
[ 94.930000] 0fe22e74: [<08062a4c>] do_ubd_request+0x91/0x40c
[ 94.930000] 0fe22edc: [<08148f01>] __blk_run_queue+0x40/0x6e
[ 94.930000] 0fe22ef0: [<08151280>] cfq_kick_queue+0x24/0x39
[ 94.930000] 0fe22f08: [<08083c86>] process_one_work+0x1ea/0x2f0
[ 94.930000] 0fe22f44: [<08084202>] worker_thread+0x174/0x2e4
[ 94.930000] 0fe22f74: [<08087e5b>] kthread+0x78/0x7f
[ 94.930000] 0fe22fb4: [<08066117>] run_kernel_thread+0x37/0x3f
[ 94.930000] 0fe22fe0: [<08059bd1>] new_thread_handler+0x60/0x87
[ 94.930000] 0fe22ffc: [<00000000>] 0x0
[ 94.930000]
[ 94.930000] Mem-Info:
[ 94.930000] Normal per-cpu:
[ 94.930000] CPU 0: hi: 42, btch: 7 usd: 7
[ 94.930000] active_anon:1202 inactive_anon:1274 isolated_anon:0
[ 94.930000] active_file:6904 inactive_file:17913 isolated_file:0
[ 94.930000] unevictable:0 dirty:1341 writeback:2209 unstable:0
[ 94.930000] free:132 slab_reclaimable:2912 slab_unreclaimable:1077
[ 94.930000] mapped:1173 shmem:10 pagetables:86 bounce:0
[ 94.930000] Normal free:528kB min:1440kB low:1800kB high:2160kB
active_anon:4808kB inactive_anon:5096kB active_file:27616kB
inactive_file:71652kB unevictable:0kB isolated(anon):0kB
isolated(file):0kB present:130048kB mlocked:0kB dirty:5364kB
writeback:8836kB mapped:4692kB shmem:40kB slab_reclaimable:11648kB
slab_unreclaimable:4308kB kernel_stack:168kB pagetables:344kB
unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? no
[ 94.930000] lowmem_reserve[]: 0 0
[ 94.930000] Normal: 0*4kB 0*8kB 17*16kB 8*32kB 0*64kB 0*128kB
0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 528kB
[ 94.930000] 24827 total pagecache pages
[ 94.930000] 0 pages in swap cache
[ 94.930000] Swap cache stats: add 0, delete 0, find 0/0
[ 94.930000] Free swap = 0kB
[ 94.930000] Total swap = 0kB
[ 94.930000] 32768 pages RAM
[ 94.930000] 1132 pages reserved
[ 94.930000] 26123 pages shared
[ 94.930000] 8586 pages non-shared
[ 94.930000] kworker/0:1: page allocation failure. order:0, mode:0x20
[ 94.930000] 0fe22c60: [<081ca1da>] dump_stack+0x1c/0x20
[ 94.930000] 0fe22c78: [<080a4981>] __alloc_pages_nodemask+0x4a0/0x4cb
[ 94.930000] 0fe22cf8: [<080bd2d7>] cache_alloc_refill+0x213/0x3fe
[ 94.930000] 0fe22d50: [<080bd5db>] kmem_cache_alloc+0x62/0x8f
[ 94.930000] 0fe22d6c: [<08062a4c>] do_ubd_request+0x91/0x40c
[ 94.930000] 0fe22dd4: [<08062e5f>] ubd_intr+0x98/0xbf
[ 94.930000] 0fe22df8: [<0809bed1>] handle_IRQ_event+0x15/0x9b
[ 94.930000] 0fe22e14: [<0809bfbd>] __do_IRQ+0x66/0xb8
[ 94.930000] 0fe22e34: [<08059136>] do_IRQ+0x1f/0x34
[ 94.930000] 0fe22e44: [<080592e6>] sigio_handler+0x46/0x5c
[ 94.930000] 0fe22e5c: [<08066e6e>] sig_handler_common+0x61/0x70
[ 94.930000] 0fe22ed4: [<08066ec3>] unblock_signals+0x46/0x57
[ 94.930000] 0fe22ee0: [<081cc3c7>] _raw_spin_unlock_irq+0x10/0x13
[ 94.930000] 0fe22eec: [<0815128b>] cfq_kick_queue+0x2f/0x39
[ 94.930000] 0fe22f08: [<08083c86>] process_one_work+0x1ea/0x2f0
[ 94.930000] 0fe22f44: [<08084202>] worker_thread+0x174/0x2e4
[ 94.930000] 0fe22f74: [<08087e5b>] kthread+0x78/0x7f
[ 94.930000] 0fe22fb4: [<08066117>] run_kernel_thread+0x37/0x3f
[ 94.930000] 0fe22fe0: [<08059bd1>] new_thread_handler+0x60/0x87
[ 94.930000] 0fe22ffc: [<00000000>] 0x0
[ 94.930000]
[ 94.930000] Mem-Info:
[ 94.930000] Normal per-cpu:
[ 94.930000] CPU 0: hi: 42, btch: 7 usd: 18
[ 94.930000] active_anon:1202 inactive_anon:1274 isolated_anon:0
[ 94.930000] active_file:6904 inactive_file:17913 isolated_file:0
[ 94.930000] unevictable:0 dirty:1341 writeback:1811 unstable:0
[ 94.930000] free:132 slab_reclaimable:2912 slab_unreclaimable:1066
[ 94.930000] mapped:1173 shmem:10 pagetables:86 bounce:0
[ 94.930000] Normal free:528kB min:1440kB low:1800kB high:2160kB
active_anon:4808kB inactive_anon:5096kB active_file:27616kB
inactive_file:71652kB unevictable:0kB isolated(anon):0kB
isolated(file):0kB present:130048kB mlocked:0kB dirty:5364kB
writeback:7244kB mapped:4692kB shmem:40kB slab_reclaimable:11648kB
slab_unreclaimable:4264kB kernel_stack:168kB pagetables:344kB
unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? no
[ 94.930000] lowmem_reserve[]: 0 0
[ 94.930000] Normal: 0*4kB 0*8kB 17*16kB 8*32kB 0*64kB 0*128kB
0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 528kB
[ 94.930000] 24827 total pagecache pages
[ 94.930000] 0 pages in swap cache
[ 94.930000] Swap cache stats: add 0, delete 0, find 0/0
[ 94.930000] Free swap = 0kB
[ 94.930000] Total swap = 0kB
[ 94.930000] 32768 pages RAM
[ 94.930000] 1132 pages reserved
[ 94.930000] 26123 pages shared
[ 94.930000] 8575 pages non-shared
--
Thanks,
//richard
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