[Devel] [PATCH] fuse kio: Replenish netaddr_cmp() with unix sockets type

[Alexey Kuznetsov]

Hello!

Fine. But I cannot figure out why we never hit this problem in user space,
it does exactly the same thing.

Also, add PCS_ADDRTYPE_RDMA just to be on safe side.
On Fri, Oct 12, 2018 at 4:58 PM Kirill Tkhai <ktkhai at virtuozzo.com> wrote:
>
> We met crash in unix socket comparison:
>
> [21519.571700] kernel BUG at fs/fuse/kio/pcs/pcs_cs.c:170!
> [21519.592534] RIP: 0010:[<ffffffffc080d4b0>]  [<ffffffffc080d4b0>] pcs_cs_find_create+0x300/0x310 [fuse_kio_pcs]
> [21519.593817] RSP: 0018:ffff8af1f86f3d18  EFLAGS: 00010293
> [21519.595102] RAX: 0000000000000000 RBX: ffff8af1d5369680 RCX: 0000000000000000
> [21519.596429] RDX: 0000000000000001 RSI: ffff8af1d5369668 RDI: ffff8af234463820
> [21519.597763] RBP: ffff8af1f86f3d58 R08: 0000000000000000 R09: 0000000000000000
> [21519.599115] R10: ffff8af33fc07340 R11: 0000000000000001 R12: ffff8af1d5369668
> [21519.600467] R13: ffff8af9e8758080 R14: ffff8af1d53696c0 R15: ffff8af234463800
> [21519.602085] FS:  0000000000000000(0000) GS:ffff8afa1fac0000(0000) knlGS:0000000000000000
> [21519.603509] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [21519.604918] CR2: 000000c4201db000 CR3: 000000104e744000 CR4: 00000000003607e0
> [21519.606371] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [21519.607805] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [21519.609604] Call Trace:
> [21519.611106]  [<ffffffffc0806b50>] cslist_alloc+0x1f0/0x400 [fuse_kio_pcs]
> [21519.612567]  [<ffffffffc08070ef>] pcs_map_complete+0x38f/0x420 [fuse_kio_pcs]
> [21519.614001]  [<ffffffffc07fca59>] fuse_complete_map_work+0x79/0xc0 [fuse_kio_pcs]
> [21519.615388]  [<ffffffff96cb7532>] process_one_work+0x182/0x440
> [21519.616772]  [<ffffffff96cb86e6>] worker_thread+0x126/0x3c0
> [21519.618270]  [<ffffffff96cb85c0>] ? manage_workers.isra.24+0x2a0/0x2a0
> [21519.619703]  [<ffffffff96cbf681>] kthread+0xd1/0xe0
> [21519.621134]  [<ffffffff96cbf5b0>] ? create_kthread+0x60/0x60
> [21519.622507]  [<ffffffff97354677>] ret_from_fork_nospec_begin+0x21/0x21
> [21519.623845]  [<ffffffff96cbf5b0>] ? create_kthread+0x60/0x60
>
> Extend netaddr_cmp() with PCS_ADDRTYPE_UNIX to make function
> not to wonder unknown socket type. Note, unix sockets do not
> care about address, since all of them are on local machine,
> there is only port has a sense.
>
> https://pmc.acronis.com/browse/VSTOR-16083
>
> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
> ---
>  fs/fuse/kio/pcs/pcs_cs.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fuse/kio/pcs/pcs_cs.c b/fs/fuse/kio/pcs/pcs_cs.c
> index 56ab3adb36db..3f34c197850f 100644
> --- a/fs/fuse/kio/pcs/pcs_cs.c
> +++ b/fs/fuse/kio/pcs/pcs_cs.c
> @@ -166,6 +166,8 @@ static inline int netaddr_cmp(PCS_NET_ADDR_T const *addr1, PCS_NET_ADDR_T const
>         case PCS_ADDRTYPE_IP6:
>                 sz = sizeof(struct in6_addr);
>                 break;
> +       case PCS_ADDRTYPE_UNIX:
> +               return 0;
>         default:
>                 BUG();
>         }
> @@ -173,7 +175,8 @@ static inline int netaddr_cmp(PCS_NET_ADDR_T const *addr1, PCS_NET_ADDR_T const
>         return memcmp(addr1->address, addr2->address, sz);
>  }
>
> -int pcs_netaddr_cmp(PCS_NET_ADDR_T const *addr1, PCS_NET_ADDR_T const *addr2)
> +static int pcs_netaddr_cmp(PCS_NET_ADDR_T const *addr1,
> +                          PCS_NET_ADDR_T const *addr2)
>  {
>         return netaddr_cmp(addr1, addr2, 0);
>  }
>