Commits · b1b9f97a0937211dbca638c476ac47ee39875661 · Kirill Smelkov / linux

20 Aug, 2019 32 commits

net/mlx5: Fix the order of fc_stats cleanup · b1b9f97a

Gavi Teitz authored Aug 11, 2019

Previously, mlx5_cleanup_fc_stats() would cleanup the flow counter
pool beofre releasing all the counters to it, which would result in
flow counter bulks not getting freed. Resolve this by changing the
order in which elements of fc_stats are cleaned up, so that the flow
counter pool is cleaned up after all the counters are released.

Also move cleanup actions for freeing the bulk query memory and
destroying the idr to the end of mlx5_cleanup_fc_stats().
Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

b1b9f97a

net/mlx5e: Fix deallocation of non-fully init encap entries · 3c140dd5

Vlad Buslov authored Aug 12, 2019

Recent rtnl lock dependency refactoring changed encap entry attach code to
insert encap entry to hash table before it was fully initialized in order
to allow concurrent tc users to wait on completion for encap entry to
finish initialization. That change required all the users of encap entry to
obtain reference to it first and for caller that creates encap to put
reference to it on error, instead of freeing the entry memory directly.
However, releasing reference to such encap entry that wasn't fully
initialized causes NULL pointer dereference in
mlx5e_rep_encap_entry_detach() which expects e->out_dev to be set and encap
to be attached to nhe:

[ 1092.454517] BUG: unable to handle page fault for address: 00000000000420e8
[ 1092.454571] #PF: supervisor read access in kernel mode
[ 1092.454602] #PF: error_code(0x0000) - not-present page
[ 1092.454632] PGD 800000083032c067 P4D 800000083032c067 PUD 84107d067 PMD 0
[ 1092.454673] Oops: 0000 [#1] SMP PTI
[ 1092.454697] CPU: 20 PID: 22393 Comm: tc Not tainted 5.3.0-rc3+ #589
[ 1092.454733] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[ 1092.454806] RIP: 0010:mlx5e_rep_encap_entry_detach+0x1c/0x630 [mlx5_core]
[ 1092.454845] Code: be f4 ff ff ff e9 11 ff ff ff 0f 1f 40 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fc 53 48 89 f3 48 83 ec 30 <48> 8b 87 28 16 04 00 48 89 f7 48 05 d0 03 00 00 48 89
 45 c8 e8 cb
[ 1092.454942] RSP: 0018:ffffb6f08421f5a0 EFLAGS: 00010286
[ 1092.454974] RAX: 0000000000000000 RBX: ffff8ab668644e00 RCX: ffffb6f08421f56c
[ 1092.455013] RDX: ffff8ab668644e40 RSI: ffff8ab668644e00 RDI: 0000000000000ac0
[ 1092.455053] RBP: ffffb6f08421f5f8 R08: 0000000000000001 R09: 0000000000000000
[ 1092.455092] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000ac0
[ 1092.455131] R13: 00000000ffffff9b R14: ffff8ab63f200ac0 R15: ffff8ab668644e40
[ 1092.455171] FS:  00007fa195bdc480(0000) GS:ffff8ab66fa00000(0000) knlGS:0000000000000000
[ 1092.455216] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1092.455249] CR2: 00000000000420e8 CR3: 0000000867522001 CR4: 00000000001606e0
[ 1092.455288] Call Trace:
[ 1092.455315]  ? __mutex_unlock_slowpath+0x4d/0x2a0
[ 1092.455365]  mlx5e_encap_dealloc.isra.0+0x31/0x60 [mlx5_core]
[ 1092.455424]  mlx5e_tc_add_fdb_flow+0x596/0x750 [mlx5_core]
[ 1092.455484]  __mlx5e_add_fdb_flow+0x152/0x210 [mlx5_core]
[ 1092.455534]  mlx5e_configure_flower+0x4d5/0xe30 [mlx5_core]
[ 1092.455574]  tc_setup_cb_call+0x67/0xb0
[ 1092.455601]  fl_hw_replace_filter+0x142/0x300 [cls_flower]
[ 1092.455639]  fl_change+0xd24/0x1bdb [cls_flower]
[ 1092.455675]  tc_new_tfilter+0x3e0/0x970
[ 1092.455709]  ? tc_del_tfilter+0x720/0x720
[ 1092.455735]  rtnetlink_rcv_msg+0x389/0x4b0
[ 1092.455763]  ? netlink_deliver_tap+0x95/0x400
[ 1092.455791]  ? rtnl_dellink+0x2d0/0x2d0
[ 1092.455817]  netlink_rcv_skb+0x49/0x110
[ 1092.455844]  netlink_unicast+0x171/0x200
[ 1092.455872]  netlink_sendmsg+0x224/0x3f0
[ 1092.455901]  sock_sendmsg+0x5e/0x60
[ 1092.455924]  ___sys_sendmsg+0x2ae/0x330
[ 1092.455950]  ? task_work_add+0x43/0x50
[ 1092.455976]  ? fput_many+0x45/0x80
[ 1092.456004]  ? __lock_acquire+0x248/0x18e0
[ 1092.456033]  ? find_held_lock+0x2b/0x80
[ 1092.456058]  ? task_work_run+0x7b/0xd0
[ 1092.456085]  __sys_sendmsg+0x59/0xa0
[ 1092.457013]  do_syscall_64+0x5c/0xb0
[ 1092.457924]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1092.458842] RIP: 0033:0x7fa195da27b8
[ 1092.459918] Code: 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 8f 0c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83
 ec 28 89 54
[ 1092.462634] RSP: 002b:00007fff94409298 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1092.464011] RAX: ffffffffffffffda RBX: 000000005d515b0e RCX: 00007fa195da27b8
[ 1092.465391] RDX: 0000000000000000 RSI: 00007fff94409300 RDI: 0000000000000003
[ 1092.466761] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000006
[ 1092.468121] R10: 0000000000404ec2 R11: 0000000000000246 R12: 0000000000000001
[ 1092.469456] R13: 0000000000480640 R14: 0000000000000016 R15: 0000000000000001
[ 1092.470766] Modules linked in: act_mirred act_tunnel_key cls_flower dummy vxlan ip6_udp_tunnel udp_tunnel sch_ingress nfsv3 nfs_acl nfs lockd grace fscache tun bridge stp llc sunrpc rdma_ucm rdma_cm
iw_cm ib_cm mlx5_ib ib_uverbs ib_core intel_rapl_msr intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp mlx5_core kvm_intel kvm irqbypass crct10dif_pclmul mei_me crc32_pclmul crc32
c_intel igb iTCO_wdt ghash_clmulni_intel ses mlxfw intel_cstate iTCO_vendor_support ptp intel_uncore lpc_ich pps_core mei i2c_i801 joydev intel_rapl_perf ioatdma enclosure ipmi_ssif pcspkr dca wmi ipmi_
si ipmi_devintf ipmi_msghandler acpi_pad acpi_power_meter ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper drm mpt3sas raid_class scsi_transport_sas
[ 1092.479618] CR2: 00000000000420e8
[ 1092.481214] ---[ end trace ce2e0f4d9a67f604 ]---

To fix the issue, set e->compl_result to positive value after encap was
initialized successfully. Check e->compl_result value in
mlx5e_encap_dealloc() and only detach and dealloc encap if the value is
positive.

Fixes: d589e785 ("net/mlx5e: Allow concurrent creation of encap entries")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

3c140dd5

Documentation: net: mlx5: Devlink health documentation updates · 26aa7ab1

Aya Levin authored Jul 23, 2019

Add documentation for devlink health rx reporter supported by mlx5.
Update tx reporter documentation.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

26aa7ab1

net/mlx5e: Report and recover from CQE with error on RQ · 8276ea13

Aya Levin authored Jun 26, 2019

Add support for report and recovery from error on completion on RQ by
setting the queue back to ready state. Handle only errors with a
syndrome indicating the RQ might enter error state and could be
recovered.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

8276ea13

net/mlx5e: RX, Handle CQE with error at the earliest stage · 0a35ab3e

Saeed Mahameed authored Jun 14, 2019

Just to be aligned with the MPWQE handlers, handle RX WQE with error
for legacy RQs in the top RX handlers, just before calling skb_from_cqe().

CQE error handling will now be called at the same stage regardless of
the RQ type or netdev mode NIC, Representor, IPoIB, etc ..

This will be useful for down stream patch to improve error CQE
handling.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

0a35ab3e

net/mlx5e: Report and recover from rx timeout · 32c57fb2

Aya Levin authored Jun 25, 2019

Add support for report and recovery from rx timeout. On driver open we
post NOP work request on the rx channels to trigger napi in order to
fillup the rx rings. In case napi wasn't scheduled due to a lost
interrupt, perform EQ recovery.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

32c57fb2

net/mlx5e: Report and recover from CQE error on ICOSQ · be5323c8

Aya Levin authored Jun 25, 2019

Add support for report and recovery from error on completion on ICOSQ.
Deactivate RQ and flush, then deactivate ICOSQ. Set the queue back to
ready state (firmware) and reset the ICOSQ and the RQ (software
resources). Finally, activate the ICOSQ and the RQ.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

be5323c8

net/mlx5e: Split open/close ICOSQ into stages · 9d18b514

Aya Levin authored Jul 02, 2019

Align ICOSQ open/close behaviour with RQ and SQ. Split open flow into
open and activate where open handles creation and activate enables the
queue. Do a symmetric thing in close flow: split into close and
deactivate.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

9d18b514

net/mlx5e: Add support to rx reporter diagnose · 9032e719

Aya Levin authored Jun 25, 2019

Add rx reporter, which supports diagnose call-back. Diagnostics output
include: information common to all RQs: RQ type, RQ size, RQ stride
size, CQ size and CQ stride size. In addition advertise information per
RQ and its related icosq and attached CQ.

$ devlink health diagnose pci/0000:00:0b.0 reporter rx
 Common config:
   RQ:
     type: 2 stride size: 2048 size: 8
   CQ:
     stride size: 64 size: 1024
 RQs:
   channel ix: 0 rqn: 4308 HW state: 1 SW state: 3 posted WQEs: 7 cc: 7 ICOSQ HW state: 1
   CQ:
     cqn: 1032 HW status: 0
   channel ix: 1 rqn: 4313 HW state: 1 SW state: 3 posted WQEs: 7 cc: 7 ICOSQ HW state: 1
   CQ:
     cqn: 1036 HW status: 0
   channel ix: 2 rqn: 4318 HW state: 1 SW state: 3 posted WQEs: 7 cc: 7 ICOSQ HW state: 1
   CQ:
     cqn: 1040 HW status: 0
   channel ix: 3 rqn: 4323 HW state: 1 SW state: 3 posted WQEs: 7 cc: 7 ICOSQ HW state: 1
   CQ:
     cqn: 1044 HW status: 0

$ devlink health diagnose pci/0000:00:0b.0 reporter rx -jp
{
    "Common config": {
        "RQ": {
            "type": 2,
            "stride size": 2048,
            "size": 8
        },
        "CQ": {
            "stride size": 64,
            "size": 1024
        }
    },
    "RQs": [ {
            "channel ix": 0,
            "rqn": 4308,
            "HW state": 1,
            "SW state": 3,
            "posted WQEs": 7,
            "cc": 7,
            "ICOSQ HW state": 1,
            "CQ": {
                "cqn": 1032,
                "HW status": 0
            }
        },{
            "channel ix": 1,
            "rqn": 4313,
            "HW state": 1,
            "SW state": 3,
            "posted WQEs": 7,
            "cc": 7,
            "ICOSQ HW state": 1,
            "CQ": {
                "cqn": 1036,
                "HW status": 0
            }
        },{
            "channel ix": 2,
            "rqn": 4318,
            "HW state": 1,
            "SW state": 3,
            "posted WQEs": 7,
            "cc": 7,
            "ICOSQ HW state": 1,
            "CQ": {
                "cqn": 1040,
                "HW status": 0
            }
        },{
            "channel ix": 3,
            "rqn": 4323,
            "HW state": 1,
            "SW state": 3,
            "posted WQEs": 7,
            "cc": 7,
            "ICOSQ HW state": 1,
            "CQ": {
                "cqn": 1044,
                "HW status": 0
            }
        } ]
}
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

9032e719

net/mlx5e: Add helper functions for reporter's basics · 11af6a6d

Aya Levin authored Jul 11, 2019

Introduce helper functions for create and destroy reporters and update
channels. In the following patch, rx reporter is added and it will use
these helpers too.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

11af6a6d

net/mlx5e: Add cq info to tx reporter diagnose · 2bf09e60

Aya Levin authored Jun 30, 2019

Add cq information to general diagnose output: CQ size and stride size.
Per SQ add information about the related CQ: cqn and CQ's HW status.

$ devlink health diagnose pci/0000:00:0b.0 reporter tx
 Common Config:
   SQ:
     stride size: 64 size: 1024
   CQ:
     stride size: 64 size: 1024
 SQs:
   channel ix: 0 tc: 0 txq ix: 0 sqn: 4307 HW state: 1 stopped: false cc: 0 pc: 0
   CQ:
     cqn: 1030 HW status: 0
   channel ix: 1 tc: 0 txq ix: 1 sqn: 4312 HW state: 1 stopped: false cc: 0 pc: 0
   CQ:
     cqn: 1034 HW status: 0
   channel ix: 2 tc: 0 txq ix: 2 sqn: 4317 HW state: 1 stopped: false cc: 0 pc: 0
   CQ:
     cqn: 1038 HW status: 0
   channel ix: 3 tc: 0 txq ix: 3 sqn: 4322 HW state: 1 stopped: false cc: 0 pc: 0
   CQ:
     cqn: 1042 HW status: 0

$ devlink health diagnose pci/0000:00:0b.0 reporter tx -jp
{
    "Common Config": {
        "SQ": {
            "stride size": 64,
            "size": 1024
        },
        "CQ": {
            "stride size": 64,
            "size": 1024
        }
    },
    "SQs": [ {
            "channel ix": 0,
            "tc": 0,
            "txq ix": 0,
            "sqn": 4307,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0,
            "CQ": {
                "cqn": 1030,
                "HW status": 0
            }
        },{
            "channel ix": 1,
            "tc": 0,
            "txq ix": 1,
            "sqn": 4312,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0,
            "CQ": {
                "cqn": 1034,
                "HW status": 0
            }
        },{
            "channel ix": 2,
            "tc": 0,
            "txq ix": 2,
            "sqn": 4317,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0,
            "CQ": {
                "cqn": 1038,
                "HW status": 0
            }
        },{
            "channel ix": 3,
            "tc": 0,
            "txq ix": 3,
            "sqn": 4322,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0,
            "CQ": {
                "cqn": 1042,
                "HW status": 0
        } ]
}
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

2bf09e60

net/mlx5e: Extend tx reporter diagnostics output · 2d708887

Aya Levin authored Jun 30, 2019

Enhance tx reporter's diagnostics output to include: information common
to all SQs: SQ size, SQ stride size.
In addition add channel ix, tc, txq ix, cc and pc.

$ devlink health diagnose pci/0000:00:0b.0 reporter tx
 Common config:
   SQ:
     stride size: 64 size: 1024
 SQs:
   channel ix: 0 tc: 0 txq ix: 0 sqn: 4307 HW state: 1 stopped: false cc: 0 pc: 0
   channel ix: 1 tc: 0 txq ix: 1 sqn: 4312 HW state: 1 stopped: false cc: 0 pc: 0
   channel ix: 2 tc: 0 txq ix: 2 sqn: 4317 HW state: 1 stopped: false cc: 0 pc: 0
   channel ix: 3 tc: 0 txq ix: 3 sqn: 4322 HW state: 1 stopped: false cc: 0 pc: 0

$ devlink health diagnose pci/0000:00:0b.0 reporter tx -jp
{
    "Common config": {
        "SQ": {
            "stride size": 64,
            "size": 1024
        }
    },
    "SQs": [ {
            "channel ix": 0,
            "tc": 0,
            "txq ix": 0,
            "sqn": 4307,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0
        },{
            "channel ix": 1,
            "tc": 0,
            "txq ix": 1,
            "sqn": 4312,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0
        },{
            "channel ix": 2,
            "tc": 0,
            "txq ix": 2,
            "sqn": 4317,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0
        },{
            "channel ix": 3,
            "tc": 0,
            "txq ix": 3,
            "sqn": 4322,
            "HW state": 1,
            "stopped": false,
            "cc": 0,
            "pc": 0
         } ]
}
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

2d708887

net/mlx5e: Extend tx diagnose function · dd921fd2

Aya Levin authored Jun 24, 2019

The following patches in the set enhance the diagnostics info of tx
reporter. Therefore, it is better to pass a pointer to the SQ for
further data extraction.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

dd921fd2

net/mlx5e: Generalize tx reporter's functionality · c50de4af

Aya Levin authored Jul 01, 2019

Prepare for code sharing with rx reporter, which is added in the
following patches in the set. Introduce a generic error_ctx for
agnostic recovery despatch.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

c50de4af

net/mlx5e: Change naming convention for reporter's functions · 06293ae4

Aya Levin authored Jul 01, 2019

Change from mlx5e_tx_reporter_* to mlx5e_reporter_tx_*. In the following
patches in the set rx reporter is added, the new naming convention is
more uniformed.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

06293ae4

net/mlx5e: Rename reporter header file · 4edc17fd

Aya Levin authored Jul 01, 2019

Rename reporter.h -> health.h so patches in the set can use it for
health related functionality.
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

4edc17fd

r8152: divide the tx and rx bottom functions · d2187f8e

Hayes Wang authored Aug 19, 2019

Move the tx bottom function from NAPI to a new tasklet. Then, for
multi-cores, the bottom functions of tx and rx may be run at same
time with different cores. This is used to improve performance.

On x86, Tx/Rx 943/943 Mbits/sec -> 945/944.
For arm platform, Tx/Rx: 917/917 Mbits/sec -> 933/933.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

d2187f8e

Merge tag 'wireless-drivers-next-for-davem-2019-08-19' of... · 932630fa

David S. Miller authored Aug 19, 2019

Merge tag 'wireless-drivers-next-for-davem-2019-08-19' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next

Kalle Valo says:

====================
wireless-drivers-next patches for 5.4

First set of patches for 5.4.

Major changes:

brcmfmac

* enable 160 MHz channel support

rt2x00

* add support for PLANEX GW-USMicroN USB device

rtw88

* add Bluetooth coexistance support
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

932630fa

Merge branch 'sctp-support-per-endpoint-auth-and-asconf-flags' · 5483ecef

David S. Miller authored Aug 19, 2019

Xin Long says:

====================
sctp: support per endpoint auth and asconf flags

This patchset mostly does 3 things:

  1. add per endpint asconf flag and use asconf flag properly
     and add SCTP_ASCONF_SUPPORTED sockopt.
  2. use auth flag properly and add SCTP_AUTH_SUPPORTED sockopt.
  3. remove the 'global feature switch' to discard chunks.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

5483ecef