linux/include
Davide Caratti a5b72a083d net/sched: add delete_empty() to filters and use it in cls_flower
Revert "net/sched: cls_u32: fix refcount leak in the error path of
u32_change()", and fix the u32 refcount leak in a more generic way that
preserves the semantic of rule dumping.
On tc filters that don't support lockless insertion/removal, there is no
need to guard against concurrent insertion when a removal is in progress.
Therefore, for most of them we can avoid a full walk() when deleting, and
just decrease the refcount, like it was done on older Linux kernels.
This fixes situations where walk() was wrongly detecting a non-empty
filter, like it happened with cls_u32 in the error path of change(), thus
leading to failures in the following tdc selftests:

 6aa7: (filter, u32) Add/Replace u32 with source match and invalid indev
 6658: (filter, u32) Add/Replace u32 with custom hash table and invalid handle
 74c2: (filter, u32) Add/Replace u32 filter with invalid hash table id

On cls_flower, and on (future) lockless filters, this check is necessary:
move all the check_empty() logic in a callback so that each filter
can have its own implementation. For cls_flower, it's sufficient to check
if no IDRs have been allocated.

This reverts commit 275c44aa19.

Changes since v1:
 - document the need for delete_empty() when TCF_PROTO_OPS_DOIT_UNLOCKED
   is used, thanks to Vlad Buslov
 - implement delete_empty() without doing fl_walk(), thanks to Vlad Buslov
 - squash revert and new fix in a single patch, to be nice with bisect
   tests that run tdc on u32 filter, thanks to Dave Miller

Fixes: 275c44aa19 ("net/sched: cls_u32: fix refcount leak in the error path of u32_change()")
Fixes: 6676d5e416 ("net: sched: set dedicated tcf_walker flag when tp is empty")
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Suggested-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:35:19 -08:00
..
acpi Merge branches 'acpi-utils', 'acpi-platform', 'acpi-video' and 'acpi-doc' 2019-11-26 10:30:49 +01:00
asm-generic powerpc updates for 5.5 #2 2019-12-06 13:36:31 -08:00
clocksource x86/hyperv: Initialize clockevents earlier in CPU onlining 2019-11-15 10:33:49 +01:00
crypto crypto: ablkcipher - remove deprecated and unused ablkcipher support 2019-11-17 09:02:49 +08:00
drm mm + drm coherent memory support for vmwgfx 2019-11-30 09:38:11 -08:00
dt-bindings ARM: Device-tree updates 2019-12-05 12:09:47 -08:00
keys powerpc updates for 5.5 2019-11-30 14:35:43 -08:00
kunit
kvm
linux ptp: fix the race between the release of ptp_clock and cdev 2019-12-30 20:19:27 -08:00
math-emu
media drm main pull for 5.5-rc1 2019-11-27 17:45:48 -08:00
misc
net net/sched: add delete_empty() to filters and use it in cls_flower 2019-12-30 20:35:19 -08:00
pcmcia
ras
rdma IB/core: Introduce rdma_user_mmap_entry_insert_range() API 2019-12-12 16:55:36 -05:00
scsi scsi: target: iscsi: Wait for all commands to finish before freeing a session 2019-11-19 21:37:35 -05:00
soc drm msm + fixes for 5.5-rc1 2019-12-06 10:28:09 -08:00
sound ASoC: Fixes for v5.5 2019-12-17 14:18:32 +01:00
target
trace This is a relatively quiet cycle for nfsd, mainly various bugfixes. 2019-12-07 16:56:00 -08:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
vdso
video
xen xen/interface: re-define FRONT/BACK_RING_ATTACH() 2019-12-20 13:44:42 +01:00