Re: [PATCH] btrfs: clear bio reference after submit_one_bio()

From: Satoru Takeuchi
Date: Tue Jan 06 2015 - 17:48:55 EST

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In reply to: Naohiro Aota: "[PATCH] btrfs: clear bio reference after submit_one_bio()"
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Hi Naota,

On 2015/01/06 1:01, Naohiro Aota wrote:
> After submit_one_bio(), `bio' can go away. However submit_extent_page()
> leave `bio' referable if submit_one_bio() failed (e.g. -ENOMEM on OOM).
> It will cause invalid paging request when submit_extent_page() is called
> next time.
>
> I reproduced ENOMEM case with the following script (need
> CONFIG_FAIL_PAGE_ALLOC, and CONFIG_FAULT_INJECTION_DEBUG_FS).

I confirmed that this problem reproduce with 3.19-rc3 and
not reproduce with 3.19-rc3 with your patch.

Tested-by: Satoru Takeuchi <takeuchi_satoru@xxxxxxxxxxxxxx>

Thank you for reporting this problem with the reproducer
and fixing it too.

NOTE:
I used v3.19-rc3's tools/testing/fault-injection/failcmd.sh
for the following "./failcmd.sh".

> ./failcmd.sh -p $percent -t $times -i $interval \
> --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \
> -- \
> cat $directory/file > /dev/null

* 3.19-rc1 + your patch

===============================================================================
# ./run
512+0 records in
512+0 records out
#
===============================================================================

* 3.19-rc3

===============================================================================
# ./run
512+0 records in
512+0 records out
[ 188.433726] run (776): drop_caches: 1
[ 188.682372] FAULT_INJECTION: forcing a failure.
name fail_page_alloc, interval 100, probability 111000, space 0, times 3
[ 188.689986] CPU: 0 PID: 954 Comm: cat Not tainted 3.19.0-rc3-ktest #1
[ 188.693834] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 188.698466] 0000000000000064 ffff88007b343618 ffffffff816e5563 ffff88007fc0fc78
[ 188.702730] ffffffff81c655c0 ffff88007b343638 ffffffff813851b5 0000000000000010
[ 188.707043] 0000000000000002 ffff88007b343768 ffffffff81188126 ffff88007b3435a8
[ 188.711283] Call Trace:
[ 188.712620] [<ffffffff816e5563>] dump_stack+0x45/0x57
[ 188.715330] [<ffffffff813851b5>] should_fail+0x135/0x140
[ 188.718218] [<ffffffff81188126>] __alloc_pages_nodemask+0xd6/0xb30
[ 188.721567] [<ffffffff81339075>] ? blk_rq_map_sg+0x35/0x170
[ 188.724558] [<ffffffffa0010705>] ? virtio_queue_rq+0x145/0x2b0 [virtio_blk]
[ 188.728191] [<ffffffffa01bd00f>] ? btrfs_submit_compressed_read+0xcf/0x4d0 [btrfs]
[ 188.732079] [<ffffffff811d99fb>] ? kmem_cache_alloc+0x1cb/0x230
[ 188.735153] [<ffffffff81181265>] ? mempool_alloc_slab+0x15/0x20
[ 188.738188] [<ffffffff811cee1a>] alloc_pages_current+0x9a/0x120
[ 188.741153] [<ffffffffa01bd0e9>] btrfs_submit_compressed_read+0x1a9/0x4d0 [btrfs]
[ 188.744835] [<ffffffffa0178621>] btrfs_submit_bio_hook+0x1c1/0x1d0 [btrfs]
[ 188.748225] [<ffffffffa018b7b3>] ? lookup_extent_mapping+0x13/0x20 [btrfs]
[ 188.751547] [<ffffffffa0179c08>] ? btrfs_get_extent+0x98/0xad0 [btrfs]
[ 188.754656] [<ffffffffa01901d7>] submit_one_bio+0x67/0xa0 [btrfs]
[ 188.757554] [<ffffffffa0193f27>] submit_extent_page.isra.35+0xd7/0x1c0 [btrfs]
[ 188.760981] [<ffffffffa019509d>] __do_readpage+0x31d/0x7b0 [btrfs]
[ 188.763920] [<ffffffffa0195f10>] ? btrfs_create_repair_bio+0x110/0x110 [btrfs]
[ 188.767382] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.770671] [<ffffffffa018f88d>] ? btrfs_lookup_ordered_range+0x13d/0x180 [btrfs]
[ 188.774366] [<ffffffffa01958ca>] __extent_readpages.constprop.42+0x2ba/0x2d0 [btrfs]
[ 188.778031] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.781241] [<ffffffffa01969b9>] extent_readpages+0x169/0x1b0 [btrfs]
[ 188.784322] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.789014] [<ffffffffa0176b0f>] btrfs_readpages+0x1f/0x30 [btrfs]
[ 188.792028] [<ffffffff8118bf5c>] __do_page_cache_readahead+0x18c/0x1f0
[ 188.795078] [<ffffffff8118c09f>] ondemand_readahead+0xdf/0x260
[ 188.797702] [<ffffffffa016c5df>] ? btrfs_congested_fn+0x5f/0xa0 [btrfs]
[ 188.800718] [<ffffffff8118c291>] page_cache_async_readahead+0x71/0xa0
[ 188.803650] [<ffffffff8118017f>] generic_file_read_iter+0x40f/0x5e0
[ 188.806480] [<ffffffff811f43be>] new_sync_read+0x7e/0xb0
[ 188.808832] [<ffffffff811f55d8>] __vfs_read+0x18/0x50
[ 188.811068] [<ffffffff811f569a>] vfs_read+0x8a/0x140
[ 188.813298] [<ffffffff811f5796>] SyS_read+0x46/0xb0
[ 188.815486] [<ffffffff81125806>] ? __audit_syscall_exit+0x1f6/0x2a0
[ 188.818293] [<ffffffff816eb8e9>] system_call_fastpath+0x12/0x17
[ 188.821005] BUG: unable to handle kernel paging request at 000000010000000c
[ 188.821984] IP: [<ffffffffa01901b3>] submit_one_bio+0x43/0xa0 [btrfs]
[ 188.821984] PGD 7bad3067 PUD 0
[ 188.821984] Oops: 0000 [#1] SMP
[ 188.821984] Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables bnep bluetooth rfkill btrfs xor raid6_pq microcode 8139too serio_raw virtio_balloon 8139cp mii nfsd auth_rpcgss nfs_acl lockd grace sunrpc virtio_blk ata_generic pata_acpi
[ 188.821984] CPU: 1 PID: 954 Comm: cat Not tainted 3.19.0-rc3-ktest #1
[ 188.821984] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 188.821984] task: ffff880037665220 ti: ffff88007b340000 task.ti: ffff88007b340000
[ 188.821984] RIP: 0010:[<ffffffffa01901b3>] [<ffffffffa01901b3>] submit_one_bio+0x43/0xa0 [btrfs]
[ 188.821984] RSP: 0018:ffff88007b3438c8 EFLAGS: 00010202
[ 188.821984] RAX: 0000000000000000 RBX: ffff88007c282ba8 RCX: 0000000000010001
[ 188.821984] RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
[ 188.821984] RBP: ffff88007b3438d8 R08: ffffea0001e33100 R09: 00000000000027df
[ 188.821984] R10: ffff88007fd1c000 R11: 0000000000dbb000 R12: ffff88007b343b40
[ 188.821984] R13: ffff88007c282ba8 R14: 0000000000006dd8 R15: ffff880071584f80
[ 188.821984] FS: 00007fdf777c5740(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000
[ 188.821984] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 188.821984] CR2: 000000010000000c CR3: 000000007bf59000 CR4: 00000000000006e0
[ 188.821984] Stack:
[ 188.821984] 0000000000001000 ffff88007b343b40 ffff88007b343938 ffffffffa0193f27
[ 188.821984] ffff88007b343938 0000000000000001 0000000000000000 ffffea0001e33180
[ 188.821984] 00000000027e0000 0000000000001000 ffff88007cc24680 ffff88007b343b50
[ 188.821984] Call Trace:
[ 188.821984] [<ffffffffa0193f27>] submit_extent_page.isra.35+0xd7/0x1c0 [btrfs]
[ 188.821984] [<ffffffffa019509d>] __do_readpage+0x31d/0x7b0 [btrfs]
[ 188.821984] [<ffffffffa0195f10>] ? btrfs_create_repair_bio+0x110/0x110 [btrfs]
[ 188.821984] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.821984] [<ffffffffa018f88d>] ? btrfs_lookup_ordered_range+0x13d/0x180 [btrfs]
[ 188.821984] [<ffffffffa01958ca>] __extent_readpages.constprop.42+0x2ba/0x2d0 [btrfs]
[ 188.821984] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.821984] [<ffffffffa01969b9>] extent_readpages+0x169/0x1b0 [btrfs]
[ 188.821984] [<ffffffffa0179b70>] ? btrfs_submit_direct+0x7b0/0x7b0 [btrfs]
[ 188.821984] [<ffffffffa0176b0f>] btrfs_readpages+0x1f/0x30 [btrfs]
[ 188.821984] [<ffffffff8118bf5c>] __do_page_cache_readahead+0x18c/0x1f0
[ 188.821984] [<ffffffff8118c09f>] ondemand_readahead+0xdf/0x260
[ 188.821984] [<ffffffffa016c5df>] ? btrfs_congested_fn+0x5f/0xa0 [btrfs]
[ 188.821984] [<ffffffff8118c291>] page_cache_async_readahead+0x71/0xa0
[ 188.821984] [<ffffffff8118017f>] generic_file_read_iter+0x40f/0x5e0
[ 188.821984] [<ffffffff811f43be>] new_sync_read+0x7e/0xb0
[ 188.821984] [<ffffffff811f55d8>] __vfs_read+0x18/0x50
[ 188.821984] [<ffffffff811f569a>] vfs_read+0x8a/0x140
[ 188.821984] [<ffffffff811f5796>] SyS_read+0x46/0xb0
[ 188.821984] [<ffffffff81125806>] ? __audit_syscall_exit+0x1f6/0x2a0
[ 188.821984] [<ffffffff816eb8e9>] system_call_fastpath+0x12/0x17
[ 188.821984] Code: c1 e0 04 48 8d 44 06 f0 48 8b 73 50 4c 8b 00 8b 40 0c 4d 8b 48 10 48 c7 43 50 00 00 00 00 f0 ff 43 74 48 8b 76 20 48 85 f6 74 4d <4c> 8b 56 18 4d 85 d2 74 44 4d 8b 58 08 49 c1 e1 0c 49 89 c8 89
[ 188.821984] RIP [<ffffffffa01901b3>] submit_one_bio+0x43/0xa0 [btrfs]
[ 188.821984] RSP <ffff88007b3438c8>
[ 188.821984] CR2: 000000010000000c
[ 188.953169] ---[ end trace 498f24be78e8baad ]---
#
===============================================================================

Thanks,
Satoru

>
> #!/bin/bash
>
> dmesgout=dmesg.txt
> start=100000
> end=300000
> step=1000
>
> # btrfs options
> device=/dev/vdb1
> directory=/mnt/btrfs
>
> # fault-injection options
> percent=100
> times=3
>
> mkdir -p $directory || exit 1
> mount -o compress $device $directory || exit 1
>
> rm -f $directory/file || exit 1
> dd if=/dev/zero of=$directory/file bs=1M count=512 || exit 1
>
> for interval in `seq $start $step $end`; do
> dmesg -C
> echo 1 > /proc/sys/vm/drop_caches
> sync
> export FAILCMD_TYPE=fail_page_alloc
> ./failcmd.sh -p $percent -t $times -i $interval \
> --ignore-gfp-highmem=N --ignore-gfp-wait=N --min-order=0 \
> -- \
> cat $directory/file > /dev/null
> dmesg > ${dmesgout}
> if grep -q BUG: ${dmesgout}; then
> cat ${dmesgout}
> exit 1
> fi
> done
>
> umount $directory
> exit 0
>
> Signed-off-by: Naohiro Aota <naota@xxxxxxxxx>
> ---
> fs/btrfs/extent_io.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 4ebabd2..4421161 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2816,8 +2816,10 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
> bio_add_page(bio, page, page_size, offset) < page_size) {
> ret = submit_one_bio(rw, bio, mirror_num,
> prev_bio_flags);
> - if (ret < 0)
> + if (ret < 0) {
> + *bio_ret = NULL;
> return ret;
> + }
> bio = NULL;
> } else {
> return 0;
>

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Next message: Pavel Machek: "Re: 3.19 on Nokia n900: audio quality awful"
Previous message: Andrey Utkin: "lustre/lnet/lnet/lib-move.c: memcpy with (struct iovec*)->iov_base, which is __user"
In reply to: Naohiro Aota: "[PATCH] btrfs: clear bio reference after submit_one_bio()"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]