From 7de07a4deb8e7707892b952daa59eff67701f0c3 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 14 Jan 2013 17:43:15 +0000 Subject: [PATCH] sfc: More sensible semantics for efx_filter_insert_filter() replace flag The 'replace' flag to efx_filter_insert_filter() controls whether the new filter may replace *any* filter, and is checked even before priority comparison. But lower-priority filters should never block insertion of higher-priority filters. Change the priority checking so that lower-priority filters are replaced regardless of the value of the flag, and rename the flag to 'replace_equal'. Signed-off-by: Ben Hutchings --- drivers/net/ethernet/sfc/filter.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/sfc/filter.c b/drivers/net/ethernet/sfc/filter.c index 8af42cd1feda..2fdd3a5f21c4 100644 --- a/drivers/net/ethernet/sfc/filter.c +++ b/drivers/net/ethernet/sfc/filter.c @@ -650,14 +650,22 @@ u32 efx_filter_get_rx_id_limit(struct efx_nic *efx) * efx_filter_insert_filter - add or replace a filter * @efx: NIC in which to insert the filter * @spec: Specification for the filter - * @replace: Flag for whether the specified filter may replace a filter - * with an identical match expression and equal or lower priority + * @replace_equal: Flag for whether the specified filter may replace an + * existing filter with equal priority * * On success, return the filter ID. * On failure, return a negative error code. + * + * If an existing filter has equal match values to the new filter + * spec, then the new filter might replace it, depending on the + * relative priorities. If the existing filter has lower priority, or + * if @replace_equal is set and it has equal priority, then it is + * replaced. Otherwise the function fails, returning -%EPERM if + * the existing filter has higher priority or -%EEXIST if it has + * equal priority. */ s32 efx_filter_insert_filter(struct efx_nic *efx, struct efx_filter_spec *spec, - bool replace) + bool replace_equal) { struct efx_filter_state *state = efx->filter_state; struct efx_filter_table *table = efx_filter_spec_table(state, spec); @@ -687,7 +695,7 @@ s32 efx_filter_insert_filter(struct efx_nic *efx, struct efx_filter_spec *spec, if (test_bit(filter_idx, table->used_bitmap)) { /* Should we replace the existing filter? */ - if (!replace) { + if (spec->priority == saved_spec->priority && !replace_equal) { rc = -EEXIST; goto out; } -- 2.30.2